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Abstract

Managing ecosystems for resilience and sustainability requires understanding how they will respond to future anthropogenic drivers such as climate change and urbanization. In fire-dependent ecosystems, predicting this response requires a focus on how these drivers will impact fire regimes. Here, we use scenarios of climate change, urbanization and management to simulate the future dynamics of the critically endangered and fire-dependent longleaf pine (Pinus palustris) ecosystem. We investigated how climate change and urbanization will affect the ecosystem, and whether the two conservation goals of a 135% increase in total longleaf area and a doubling of fire-maintained open-canopy habitat can be achieved in the face of these drivers. Our results show that while climatic warming had little effect on the wildfire regime, and thus on longleaf pine dynamics, urban growth led to an 8% reduction in annual wildfire area. The management scenarios we tested increase the ecosystem's total extent by up to 62% and result in expansion of open-canopy longleaf by as much as 216%, meeting one of the two conservation goals for the ecosystem. We find that both conservation goals for this ecosystem, which is climate-resilient but vulnerable to urbanization, are only attainable if a greater focus is placed on restoration of non-longleaf areas as opposed to maintaining existing longleaf stands. Our approach demonstrates the importance of accounting for multiple relevant anthropogenic threats in an ecosystem-specific context in order to facilitate more effective management actions. Copyright © 2014 Elsevier Ltd. All rights reserved.

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... Recent work by Chen et al. [51] presented burstiness -strong intermittent activity between longer periods of lulls -of longleaf cone production as a new method for potentially helping to compare and predict the timing of good seed crop years between longleaf pine stands. Many factors such as genetics and site characteristics have been studied and shown to impact these reproductive trends, but relationships with climate are often complex and not fully understood [47,52,53] . ...
... Wildfire is a substantial factor in longleaf reestablishment and maintenance [17,21,52] . Without the presence of frequent fires, faster-growing yet less fire-resistant hardwoods and other pine species are prone to outgrow and outcompete longleaf pine [17] . ...
... Central to this issue is that wildlife regimes throughout the southeast have been anthropogenically drastically reduced since times of pre-European settlement [17,21] . However, relationships between fire, anthropogenic activity, climate, and energy storage can be complex, and not all is known about each factor [52,61] . For instance, the grass stage unique to longleaf pine allows for high survivability of low-intensity fires, yet may represent a trade-off with lowered survivability to drought stress than other pines such as loblolly [35,44] . ...
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Climate change poses many risks to economically and ecologically crucial species. Longleaf pine (Pinus palustris Mill.) trees are keystone species that were once dominant across the southeastern United States, but now occupy less than 5% of their historic range and are thus classified as endangered. Here we review the current status and challenges facing longleaf pine trees, what is known on how changing climate will impact longleaf growth and reproduction, and gaps in the literature that are important to address. We found that many fundamental aspects of longleaf pine growth and reproduction are understood. However, these systems are complex, and not all is known about each factor that influences the relationship between climate, growth, and reproductive output. Additionally, long-term data sets capable of examining all relevant factors in these relationships do not currently exist. To fill necessary gaps, we recommend a joint approach between using readily available data sets and establishing new long-term monitoring plots targeted to collect data on missing or poorly understood conditions. This review provides a clue from an ecological complexity perspective to understand and manage longleaf pine forests under climate change.
... Study of post-fire bacterial community responses should expand concepts that relate fire as an ecological process 20 to ground-level fuel dynamics and fire feedbacks, as well as compositional variation in savanna/grassland microbial communities 21 . Understanding post-fire bacterial feedback effects on fuel decomposition and plant community recovery will help predict microbial effects on fuel dynamics and thus fire regimes, as well as microbial and functional adaptations to changes in fire regimes related to both climate and human effects [22][23][24][25] . This new element of microbial effects in fire ecology may also be useful in guiding management of ecosystems, especially those with old-growth characteristics that reflect long evolutionary histories in association with fire, especially in high diversity hotspots of biodiversity and endemism 22,23 . ...
... Maintaining substrate heterogeneity via frequent, low intensity fire is likely important to maintain larger microbial biodiversity on long-term scales, which affect microbial ecosystem functions such as decomposition, nutrient cycling 83 , and plant interactions 13 and plant recovery 84 that are important to consider for adaptive fire management 60,85 . This is especially important in consideration of changes in fire regimes related to human and climate effects 24,25 . The biodiversity of bacterial communities should be a characteristic of old-growth fire-frequented ecosystems 23 that complements the large plant diversity characteristic of this and other pine savanna biodiversity hotspots 33 . ...
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Bacterial communities associated with vegetation-soil interfaces have important roles in terrestrial ecosystems. These bacterial communities, studied almost exclusively in unburnt ecosystems or those affected by rare, high-intensity wildfires, have been understudied in fire-frequented grasslands and savannas. The composition of ground-level bacterial communities was explored in an old-growth pine savanna with a centuries-long management history of prescribed fires every 1–2 years. Using 16S metabarcoding, hypotheses were tested regarding differences in bacterial families of litter and soil surface substrates in patches of ground layer vegetation that were naturally burnt or unburnt during landscape-level prescribed fires. Litter/soil substrates and fire/no fire treatments explained 67.5% of bacterial community variation and differences, driven by relative abundance shifts of specific bacterial families. Fires did not strongly affect plant or soil variables, which were not linked to bacterial community differences. Litter/soil substrates and the naturally patchy frequent fires appear to generate microhabitat heterogeneity in this pine savanna, driving responses of bacterial families. Prescribed fire management may benefit from considering how fire-altered substrate heterogeneity influences and maintains microbial diversity and function, especially in these fiery ecosystems. Frequent, low-intensity fires appear ecologically important in maintaining the diverse microbial foundation that underlie ecosystem processes and services in fire-frequented habitats.
... Collectively, the loss and alteration of these ecosystems have significant implications not only for longleaf pine, Kupfer et al. Fire Ecology (2022) 18:27 the wildland-urban interface and altering the landscape context within which longleaf pine forests are embedded (Costanza et al. 2015;Radeloff et al. 2018). These ongoing threats will occur at a time when the region is expected to experience significant climatic changes that will affect species and ecosystems in complex ways (Carter et al. 2018). ...
... If climate change further narrows the availability of suitable burning conditions, managers may need to consider alternative burning approaches (e.g., burning at different times or in different seasons) or the increased use of more expensive mechanical or chemical options to meet future management goals (Provencher et al. 2001). Projected patterns of urbanization would impose an additional challenge to longleaf pine fire management as more stands are brought into an expanding wildland-urban interface (Costanza et al. 2015). Effectively addressing these intertwined challenges will be critical because any reduction in prescribed burning is likely to result in decreased biological diversity and could contribute to increased wildfires and, with that, the potential to threaten human developments and negatively influence regional air quality (Mitchell et al. 2014). ...
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Background Projected trajectories of climate and land use change over the remainder of the twenty-first century may result in conditions and situations that require flexible approaches to conservation planning and practices. For example, prescribed burning is a widely used management tool for promoting longer-term resilience and sustainability in longleaf pine ecosystems of the southeastern United States, but regional stressors such as climatic warming, changing fire conditions, and an expanding wildland-urban interface may challenge its application. To facilitate the development of fire management strategies that account for such changes, we surveyed nearly 300 fire managers to elicit information on the criteria used for prioritizing burn sites, current burning practices and constraints, and expectations for changes in burning opportunities, including those pertaining to climate change and urban growth. Results Respondents noted that their most common criteria for selecting longleaf pine stands for burning were fire history, ecosystem health, and fuel reduction, with the presence of threatened and endangered species also given priority by public land managers. Many respondents (38%) cited recent burn frequencies that fall short of historic burn intervals. Barriers to burning included legal, institutional, and managerial constraints, such as proximity to human developments, public concerns, and risk aversion, as well as environmental and resource constraints, including weather, air quality restrictions, and lack of personnel, equipment, or funding. Roughly half of all respondents expect that opportunities to burn will be reduced over the next 30 years, particularly during the growing season. Fire manager perceptions of factors that will limit prescribed burning in the future include a similar suite of constraints, many of which will be affected by projected regional changes in land use and climate. Conclusions On an organizational level, burn window availability and resource limitations constrain prescribed burning practices. More broadly, policy and legal frameworks coupled with trends in urbanization and climate change are expected to interact with operational constraints to challenge managers’ abilities to implement landscape-scale burning strategies and achieve restoration goals. Additional research and engagement with fire managers are needed to investigate opportunities for introducing policy flexibility, leveraging shared management interests, and developing creative solutions to expand burning opportunities.
... Miller et al. (2017) developed a geospatial layer of prairie dog colony locations that would be useful to set initial conditions, while the observed expansion of prairie dog colonies during the 2002-2007 persistent drought could be useful for model evaluation (Table 3). Additional information on prairie dog dispersal as a function of climatic and non-climatic factors (e.g., Cincotta et al., 1987;Dalsted et al., 1981;Derner et al., 2006;Garrett and Franklin, 1988;Hoogland, 2001), rate of expansion during drought, and effects of prairie dog colonies/grazing on vegetation state and composition • Stock/flow module - (Daniel et al., 2017a;Miller et al., 2017) • Vegetation response to climate - (Smart et al., 2007) • • Dispersal kernels - (Frid et al., 2013;Frid and Wilmshurst, 2009;Miller et al., 2017) • • Geospatial layer of prairie dog colonies for initialization - • Dispersal - (Cincotta et al., 1987;Garrett and Franklin, 1988;Dalsted et al., 1981;Hoogland, 2001) • Vegetation state and composition - (Krueger, 1986;Archer et al., 1987) • Rate of expansion during drought Fire • Fire dynamics under persistent drought (2002)(2003)(2004)(2005)(2006)(2007) • Dry/wet cycles • Vegetation impacts - (Miller et al., 2015;Daniel et al., 2017b;Halofsky et al., 2013;Blankenship et al., 2015;Costanza et al. 2015) • Area burned in drought, normal years T.A. Beeton et al. Climate Risk Management xxx (xxxx) xxx-xxx (e.g., Archer et al., 1987;Fahnestock and Detling, 2002;Krueger, 1986) would further support model development. ...
... The fire sub-model directly and indirectly impacts biomass availability and distribution for bison. Several studies have simulated fire dynamics and impacts to vegetation using STSMs (Blankenship et al., 2015;Costanza et al., 2015;Daniel et al., 2017b;Halofsky et al., 2013;Miller et al., 2015). Fire dynamics were only briefly discussed by local managers, specifically with regard to decreased fire during the most recent persistent drought period, and the ebb and flow of fire with respect to wet and dry cycles, both of which could be useful to evaluate fire behavior within the model (Table 3). ...
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Policies directing agencies and public land managers to incorporate climate change into management face several barriers. These stem, in part, from a disconnect between the information that is produced and the information needs of local resource managers. A disproportionate focus on the natural and physical sciences in climate vulnerability and adaptation assessment obscure understandings of complex social systems and the interactions and feedbacks in social-ecological systems. We use a qualitative case study of bison management on Department of the Interior-managed and tribal lands to explore how a social-science driven Determinants and Analogue Vulnerability Assessment (DAVA) can inform ecological response models, specifically simulation models that account for multiple drivers of change. First, we illustrate how a DAVA approach can help to: 1) identify key processes, entities, and interactions across scales; 2) document local impacts, indicators, and monitoring efforts of drought and climate; and 3) identify major tradeoffs and uncertainties. We then demonstrate how qualitative narratives can inform simulation models by: 1) prioritizing model components included in modeling efforts; 2) framing joint management and climate scenarios; and 3) parameterizing and evaluating model performance. We do this by presenting a conceptual joint agent-based/state-and-transition simulation modeling framework. Simulation models can represent multiple interacting variables and can identify surprising, emergent outcomes that might not be evident from qualitative analysis alone, and we argue that qualitative case studies can ground simulation models in local contexts and help make them more structurally realistic and useful. Together, these can provide a step toward developing actionable climate change adaptation strategies.
... Landscape modeling has been used previously to simulate management, policy, climate change, and resource or energy demand alternatives. In most forest landscape modeling examples, scenarios represent systematic variations in specific model variables designed by researchers to test hypotheses about the influence of each variable on landscape characteristics and processes (Radeloff et al. 2006;Hemstrom et al. 2007;Costanza et al. 2012;Duveneck et al. 2014a;Halofsky et al. 2014;Costanza et al. 2015b). In other cases, scenarios represent management alternatives for single-owner landscapes defined by the research team or a government agency (Gustafson et al. 2006b;Zollner et al. 2008;Côté et al. 2010;Gustafson et al. 2011). ...
... This stochastic, empirical simulation model was designed to project the spatial interactions of succession, natural disturbances, and management at broad spatial scales (up to 250,000 ha) over decades to centuries (Kurz et al. 2000;ESSA Technologies Ltd. 2007;ESSA Technologies Ltd. 2008). STMs and VDDT/TELSA in particular have been widely employed to simulate the effects of management in other landscapes of conservation interest (Forbis et al. 2006;Provencher et al. 2007;Hemstrom et al. 2007;Costanza et al. 2012Costanza et al. , 2015aCostanza et al. , 2015b. ...
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Context. Broad-scale land conservation and management often involve applying multiple strategies in a single landscape. However, the potential outcomes of such arrangements remain difficult to evaluate given the interactions of ecosystem dynamics, resource extraction, and natural disturbances. The costs and potential risks of implementing these strategies make robust evaluation critical. Objectives. We used collaborative scenario modeling to compare the potential outcomes of alternative management strategies in the Two Hearted River watershed in Michigan’s Upper Peninsula to answer key questions: Which management strategies best achieve conservation goals of maintaining landscape spatial heterogeneity and conserving mature forests and wetlands? And how does an increase in wildfire and windthrow disturbances influence these outcomes? Methods. Scenarios were modeled using the VDDT/ TELSA state-and-transition modeling suite, and resulting land cover maps were analyzed using ArcGIS, FRAGSTATS, and R statistical software. Results. Results indicate that blending conservation strategies, such as single-ownership forest reserves and working forest conservation easements in targeted areas of the landscape, may better achieve these goals than applying a single strategy across the same area. However, strategies that best achieve these conservation goals may increase the sensitivity of the landscape to changes in wildfire and windthrow disturbance regimes. Conclusions. These results inform decision-making about which conservation strategy or combination of strategies to apply in specific locations on the landscape to achieve optimum conservation outcomes, how to best utilize scarce financial resources, and how to reduce the financial and ecological risks associated with the application of innovative strategies in an uncertain future.
... A variety of approaches to capturing climate change in STSM are emerging [16][17][18][19]. Two specific examples of these efforts include Nowacki and Abrams, who incorporated temperature patterns and species tolerance into STSM to project potential vegetation changes and predict future tree species habitats [20], and Costanza and colleagues, who used historical emissions data to inform and develop scenarios of alternative wildfire probabilities to capture climate change using STSM and determine the impacts that varied anthropogenic disturbances may have on the resilience of a Pinus palustris ecosystem [21]. ...
... Similar to findings by Nowacki et al. and Costanza et al., we found that management is an important determinant of the landscape outcomes in the face of climate change [20,21]. Here, management as defined by each of the three scenarios, influences the landscape more than an increase in the probability of wildfire and windthrow. ...
Article
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Comparisons of the potential outcomes of multiple land management strategies and an understanding of the influence of potential increases in climate-related disturbances on these outcomes are essential for long term land management and conservation planning. To provide these insights, we developed an approach that uses collaborative scenario development and state-and-transition simulation modeling to provide land managers and conservation practitioners with a comparison of potential landscapes resulting from alternative management scenarios and climate conditions, and we have applied this approach in the Wild Rivers Legacy Forest (WRLF) area in northeastern Wisconsin. Three management scenarios were developed with input from local land managers, scientists, and conservation practitioners: 1) continuation of current management, 2) expanded working forest conservation easements, and 3) cooperative ecological forestry. Scenarios were modeled under current climate with contemporary probabilities of natural disturbance and under increased probability of windthrow and wildfire that may result from climate change in this region. All scenarios were modeled for 100 years using the VDDT/TELSA modeling suite. Results showed that landscape composition and configuration were relatively similar among scenarios, and that management had a stronger effect than increased probability of windthrow and wildfire. These findings suggest that the scale of the landscape analysis used here and the lack of differences in predominant management strategies between ownerships in this region play significant roles in 738 AIMS Environmental Science Volume 2, Issue 3, 737-763. scenario outcomes. The approach used here does not rely on complex mechanistic modeling of uncertain dynamics and can therefore be used as starting point for planning and further analysis.
... Ecologically appropriate management of longleaf pine habitats requires an understanding of potentially unique ways that climate, fire, and species composition interact in different communities . While the effects of climate, fire, and species composition on longleaf pine tree growth have been examined separately (Ames et al., 2015;Costanza et al., 2015;Loudermilk et al., 2016), they have not been assessed altogether or at the community scale. A deeper understanding of longleaf pine tree growth and stand structure is necessary to manage and restore longleaf ecosystems in the face of anthropogenic threats such as continued logging and conversion, fire mismanagement and climate change (Gilliam, 2021;Van Lear et al., 2005). ...
Article
The longleaf pine (Pinus palustris) savanna is an endangered ecosystem within a global biodiversity hotspot. However, most studies of longleaf habitats have not considered their distinct structure and function among unique communities, which are critical for developing appropriate management strategies. We aim to assess how differences in climate, fire, and species composition interact and relate to longleaf pine densities and growth rates in distinct communities. We surveyed longleaf pine stand structure (density by size and age classes) and estimated growth rates using 516 tree cores across 5 community types (69 plots, each ≤ 160 m²). Surveys covered the range of longleaf pine in Florida, USA, including the southernmost extent of the species range, and included all communities where longleaf are dominant (sandhill, upland pine, and mesic, wet, and scrubby flatwoods). We used an NMDS ordination to classify communities by species composition. We used linear mixed-effects models to examine the effect of community type on longleaf pine density and growth rates and then used recursive partitioning and regression tree analyses to identify how climate, fire, and species composition affect density and growth rates. We found that stand structure and species composition were different across communities, with upland pine being the most species rich and having the highest density of mature trees, whereas growth rates were not statistically different across communities. Across communities, unique interactions between climate, fire, and species composition, resulted in differences in stand structure and growth rates. In general, tree and grass stage densities were best predicted by species composition and fire rather than by climate, whereas growth rates were best predicted by climate. Having included the southernmost extent of longleafs range we show that longleaf growth rates increased with higher temperatures, but this effect is reversed in dry conditions. Our results suggest that longleaf growth rates across its range will be more sensitive to current and future climate change than longleaf population density. Furthermore, while controlling competition from hardwoods has been a focus of longleaf restoration, our results suggest that species that facilitate longleaf establishment may be equally important in restoring and managing these habitats. Managers should design and apply regional and community specific plans that take into account relationships between fire and associated species composition under a changing climate, which will influence strand structure and tree growth differently in different communities.
... For example, in a survey of 12 urban green roofs across Chicago, arbuscular mycorrhizal (AM) fungal composition largely varied with ecosystem age (Chaudhary et al., 2019), and not soil chemistry or plant communities as in natural systems (Kivlin et al., 2011). Finally, the combined disturbance of urbanization and wildfires may not be additive and instead may have unknown synergistically negative effects on belowground ecosystems (Costanza et al., 2015). ...
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Wildfires are increasing in frequency and intensity as drier and warmer climates increase plant detrital fuel loads. At the same time, increases in urbanization position 9% of fire-prone land within the United States at the wildland–urban interface. While rarely studied, the compounded effects of urbanization and wildfires may have unknown synergistically negative effects on ecosystems. Previous studies at the wildland–urban interface often focus on aboveground plant communities, but belowground ecosystems may also be affected by this double disturbance. In particular, it is unclear how much fire and urbanization independently or interactively affect nutritional symbioses such as those between arbuscular mycorrhizal (AM) fungi and the majority of terrestrial plants. In November 2016, extreme drought conditions and long-term fire suppression combined to create a wildfire within the Great Smoky Mountains National Park and the neighboring exurban city of Gatlinburg, TN. To understand how the double disturbance of urbanization and fire affected AM fungal communities, we collected fine roots from the 5 dominant understory species in September 2018 at each of 18 sites spanning 3 burn severities in both exurban and natural sites. Despite large variation in burn severity, plant species identity had the largest influence on AM fungi. AM fungal colonization, richness, and composition all varied most among plant species. Fire and urbanization did influence some AM fungal metrics; colonization was lower in burned sites and composition was more variable among exurban locations. There were no interactions among burn severity and urbanization on AM fungi. Our results point to the large influence of plant species identity structuring this obligate nutritional symbiosis regardless of disturbance regime. Therefore, the majority of AM fungal taxa may be buffered from fire-induced ecosystem changes if plant community composition largely remains intact, plant species life history traits allow for AM fungal persistence after fire disturbance, and/or nearby undisturbed habitat can act as an inoculum source for recolonization following fires. Thus, it is critical to maintain natural, undisturbed habitats interspersed within the wildland–urban interface.
... Models for each BpS and their accompanying description documents (collectively referred to as the BpS model library) synthesize fundamental ecological information about ecosystem dynamics, structure, composition, and disturbance regimes. The BpS model library has been widely applied to a variety of land management needs such as National Forest planning (Nantahala and Pisgah National Forests 2020), regional assessments (DeMeo et al. 2018), evaluating management scenarios (Costanza et al. 2015a), and supporting stakeholder-driven planning efforts ). These products create the first comprehensive, nation-wide baseline for assessing current vegetation conditions, and, to our knowledge, represent the largest participatory ecological modeling effort (e.g., Voinov et al. 2018) completed in the USA. ...
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In the context of widespread ecological changes, land managers and policymakers confront the need to prioritize ecosystem restoration and fuel management activities across large areas to sustain ecosystem services. Reference conditions inform prioritization efforts by providing a baseline from which to measure where and how vegetation and fuels have changed, but until recently the USA lacked a complete set of reference conditions. We describe the ongoing development of a comprehensive set of vegetation reference conditions based on over 900 quantitative vegetation dynamic models and accompanying description documents for terrestrial ecosystems in the USA. These models and description documents, collaboratively developed by more than 800 experts around the country through the interagency LANDFIRE Program, synthesize fundamental ecological information about ecosystem dynamics, structure, composition, and disturbance regimes before European‐American settlement. These products establish the first comprehensive national baseline for measuring vegetation change in the USA, providing land managers and policymakers with a tool to support vegetation restoration and fuel management activities at regional to national scales. Users have applied these products to support a variety of land management needs including exploring ecosystem dynamics, assessing current and desired conditions, and simulating the effects of management actions. In an era of rapid ecological change, these products provide land managers with an adaptable tool for understanding ecosystems and predicting possible future conditions.
... Climate change-driven trends in severe drought and storm events pose a challenge to the adaptive capacity of forests in southeastern USA (Mitchell et al., 2014). Longleaf pine (Pinus palustris Mill.), a species of conservation focus in the region, is adapted to future-climate conditions (Costanza et al., 2015). Commonly occupying dry sandy sites, longleaf pine woodland occurs along the southeastern coastal plain from eastern Texas to southeastern Virginia and into central Florida, USA (Van Lear et al., 2005). ...
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The Adaptive Silviculture for Climate Change (ASCC) network tests silvicultural treatments to promote ‘resistance’ or ‘resilience’ to climate change or speed ‘transition’ to new forest types. Based on projected increases in air temperatures and within-season dry periods in southeastern USA, we installed resistance, resilience and transition treatments involving species selection and varied intensities of density reduction, plus an untreated control, in mixed longleaf pine-hardwood woodland in southwest Georgia USA. Within a year of treatment a tropical cyclone, Hurricane Michael, exposed the site to the unforeseen climatic stress of >44-m s−1 winds. We measured inventory plots post-cyclone and compared the data to pre-storm and pre-treatment values. We analysed stand density index (metric SDI, species maximum value = 1000), stand complexity index (SCI), composition and individual tree characteristics. The ASCC treatments decreased both SDI (from 220 to 124 in the transition treatment) and SCI. The cyclone did not greatly decrease SDI (mean decrease 4.5 per cent) and decreased SCI only in the Controls. Xeric hardwoods were more prone to damage than other functional groups, and ordination showed that the cyclone shifted species composition to greater longleaf pine dominance. Taller trees were more likely to be damaged, except in the resilience treatment, which had a relatively large representation of shorter, more easily damaged xeric hardwoods. The open canopy of the longleaf-hardwood woodland, only 22 per cent of maximum SDI before treatment, evidently fostered wind-firmness, thereby limiting the destructive effect of the cyclone. The sensitivity of xeric hardwoods to hurricane damage suggests that there may be a trade-off between wind tolerance and drought tolerance among functional groups. Maintaining a mixture of drought and wind-resistant species, as in the resilience treatments, may provide broader insurance against multiple climate change impacts in longleaf pine and other forested systems dominated by a single foundation species.
... thick bark, buried buds or meristems, light or winged seeds) were prominent in many ecosystems, including pyrophyllic longleaf pine (Pinus palustris) ecosystems that are a focus of regional conservation efforts (e.g. Costanza et al. 2015;Stephens et al. 2019). ...
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Prescribed burning is a critical tool for managing wildfire risks and meeting ecological objectives, but its safe and effective application requires that specific meteorological criteria (a ‘burn window’) are met. Here, we evaluate the potential impacts of projected climatic change on prescribed burning in the south-eastern United States by applying a set of burn window criteria that capture temperature, relative humidity and wind speed to projections from an ensemble of Global Climate Models under two greenhouse gas emission scenarios. Regionally, the percentage of suitable days for burning changes little during winter but decreases substantially in summer owing to rising temperatures by the end of the 21st century compared with historical conditions. Management implications of such changes for six representative land management units include seasonal shifts in burning opportunities from summer to cool-season months, but with considerable regional variation. We contend that the practical constraints of rising temperatures on prescribed fire activities represent a significant future challenge and show that even meeting basic burn criteria (as defined today) will become increasingly difficult over time, which speaks to the need for adaptive management strategies to prepare for such changes.
... In this exploratory study we have identified patterns in productivity and phenology shifts across the range, but our understanding of the mechanisms behind these patterns is still speculative and in need of further investigation. Long-term impacts of climate change on RCWs will depend on how the birds (and land managers) respond not only to changes in the phenology of food and other critical resources, but also how they respond to shifting forest communities (Iverson and Prasad 2001), changing fire regimes (Costanza et al. 2015), altered frequency and intensity of hurricanes and tropical storms (Stanturf et al. 2007), potential increases in southern pine beetle infestations (Dendroctonus frontalis; Gan 2004), and the capacity of RCWs to continue to adjust their behavior to keep pace with the changing system in which they live. ...
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Many temperate bird species are breeding earlier in response to warming temperatures. We examined the effects of climate on breeding phenology and productivity in 19 populations across the range of the Red-cockaded Woodpecker (Dryobates borealis), an endangered species endemic to pine (Pinus spp.) forests in the southeastern United States. Red-cockaded Woodpeckers nested earlier in warmer springs and delayed nesting in wetter springs. Earlier nesting and larger group sizes resulted in higher productivity. Spring temperatures have warmed over time across the range, but this has not led to range-wide advances in nesting date over time. Coastal and northern populations have exhibited a trend of earlier nesting over time, but the response of inland populations has been variable, including some populations in which nesting has become later over time. Geographic patterns included high and increasing productivity at higher latitudes, and declining productivity in the southwestern portion of the range, suggesting a possible shift in acceptable climate conditions for the species. Earlier nesting over time was associated with increasing productivity at higher latitudes, while elsewhere earlier nesting over time was associated with declining or stable productivity, suggesting that populations differ in their ability to adjust to a changing climate. The Red-cockaded Woodpecker is a habitat specialist heavily reliant on habitat management and has little capacity to shift its range, so its long-term viability will depend on its ability to adjust in place to changing local conditions.
... [36] simulated the spatial landscape dynamics resulting from different biomass production scenarios to meet bioenergy demands in North Carolina. Exogenous economic demand was incorporated by using the outcomes of an economic timber supply model [37] as target areas for the STM. They found that satisfying bioenergy demands from forestry rather than biomass crops increased forest area but decreased ecological quality (i.e. ...
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Purpose of Review The purpose of this review is to analyse recent advances in ecological-economic modelling designed to inform desirable landscape composition and configuration. We explore how models capture the economic and ecological consequences of landscape pattern, and potential feedbacks to the responses by policy or landholders. Recent Findings Modelling approaches are becoming increasingly interlinked, coupling components of empirical-statistical modelling, spatial and bioeconomic simulation, land-use optimization and agent-based models. We analyse recent methodological advances and find that only few examples capture feedbacks between landscape pattern and decision-making. Summary We outline how future hybrid models could build on these recent advances by inter alia an improved representation of landscape patterns, refining the theory behind decision-making, incorporating uncertainty and reducing model complexity. We conclude that coupling recent developments in land-use optimization and agent-based models may help bridge gaps between modelling philosophies as well as parsimony vs. complexity. This fruitful field of research could help to improve understanding on the role of landscape pattern in social-ecological systems.
... Compared to other Southern pines, longleaf pine ecosystems are more tolerant of wildfire and more resistant to pests such as Southern pine beetle (Dendroctonus frontalis). Both forms of disturbances are expected to exacerbate under warmer, drier conditions (Costanza et al., 2015;Hodges et al., 1979;Martinson et al., 2007;Southeast Regional Partnership for Planning and Sustainability, 2009). Longleaf pine are also timber resources, and landowners may manage these ecosystems as profitable investments (Alavalapati et al., 2002;America's Longleaf, 2018). ...
... The available bioclimatic niche models that predominate the predictions about woodpeckers (Figure 3b) provide potential broad-scale range distribution trends (Pearson & Dawson, 2003) and ground cover composition (James, Hess, Kicklighter, & Thum, 2011), which are indistinguishable at the scale of plant functional groups. Therefore, even with the persistence of the needle-leaved evergreen biome or long-leaf pine successional stages within this region (Costanza, Terando, McKerrow, & Collazo, 2015), finer scale niche attributes are important (Schiegg et al., 2002) and should be included in model integration. ...
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The structure and composition of forest ecosystems are expected to shift with climate‐induced changes in precipitation, temperature, fire, carbon mitigation strategies, and biological disturbance. These factors are likely to have biodiversity implications. However, climate‐driven forest ecosystem models used to predict changes to forest structure and composition are not coupled to models used to predict changes to biodiversity. We proposed integrating woodpecker response (biodiversity indicator) with forest ecosystem models. Woodpeckers are a good indicator species of forest ecosystem dynamics, because they are ecologically constrained by landscape‐scale forest components, such as composition, structure, disturbance regimes, and management activities. In addition, they are correlated with forest avifauna community diversity. In this study, we explore integrating woodpecker and forest ecosystem climate models. We review climate–woodpecker models and compare the predicted responses to observed climate‐induced changes. We identify inconsistencies between observed and predicted responses, explore the modeling causes, and identify the models pertinent to integration that address the inconsistencies. We found that predictions in the short term are not in agreement with observed trends for 7 of 15 evaluated species. Because niche constraints associated with woodpeckers are a result of complex interactions between climate, vegetation, and disturbance, we hypothesize that the lack of adequate representation of these processes in the current broad‐scale climate–woodpecker models results in model–data mismatch. As a first step toward improvement, we suggest a conceptual model of climate–woodpecker–forest modeling for integration. The integration model provides climate‐driven forest ecosystem modeling with a measure of biodiversity while retaining the feedback between climate and vegetation in woodpecker climate change modeling.
... Internally, supportive leadership helped to advance climate change-related planning efforts within some states, while interviews verified that the political environment in other states made it difficult to address climate change directly. 4 In 2018 the Southeast Climate Science Center was renamed the Southeast Climate Adaptation Science Center. ...
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This report, produced in support of the Southeast Conservation Adaptation Strategy, reviews how states in the southeastern United States have addressed current and projected climate change in their recently-updated State Wildlife Action Plans (SWAPs). Researchers associated with the Vital Futures project (a collaboration among National Wildlife Federation, University of South Carolina, and North Carolina State University) examined state wildlife action plans from 15 southeastern states and Puerto Rico in order to: 1) identify the various approaches used to address climate change in the recent SWAP updates, 2) highlight key commonalities and differences among the states, and 3) improve understanding of the challenges and opportunities that state agencies face as they address climate change risks. Methods included detailed review of the SWAPs and follow-up interviews with SWAP coordinators. An adapted version of the “climate-smart conservation cycle” [11] provided the conceptual framework for the data analysis. This examination is intended to illuminate elements of success in these plans and facilitate further progress in both state and regional conservation efforts.
... The effects of urbanization on vegetation degradation have drawn increasing attention (Imhoff et al., 2004;Costanza et al., 2015;Pickens et al., 2017). Studies of the effects of urbanization on plant function in ecosystems at the landscape scale have mainly documented the loss of vegetation caused by the modification of farmland into urban land, for example in the United States (Milesi et al., 2003), in Europe (Gingrich et al., 2015), and in China (Tian and Qiao, 2014;Yu et al., 2009). ...
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Over that past decade, ecological restoration practices have expanded globally. However, the effectiveness of ecological restoration depends on the complex interactions of various natural and socioeconomic factors, about which there is limited scientific understanding and thus provides an important research frontier. This paper analyzed the relationship between regional scale vegetation restoration and the process of urbanization using the Loess Plateau of China as a case study. This region has experienced both rapid urbanization and a high number of vegetation restoration activities. Urbanization and vegetation restoration can be considered as extremes on the spectrum of environment preservation activities. Three separate spatial correlation analyses between urbanization and vegetation restoration were identified, resulting in: 1) insignificant correlations in saturated urban areas; 2) significant negative correlations in peri-urban areas; and 3) significant positive correlations in undeveloped areas. The relationship between urbanization and vegetation restoration is thus stage-dependent. Impacts of urbanization on vegetation degradation has improved but has not been fully addressed by large scale vegetation restoration. Regardless of whether the county or grid scale is used, peri-urbanization was found to be the critical factor affecting the effectiveness of vegetation restoration over both time and space. Therefore, peri-urbanized areas are viewed as priorities for improving the coupling of urban development and vegetation restoration.
... Therefore, fire (both wild and prescribed) can significantly and positively impact seedling development by reducing competition. Although fire tolerance makes longleaf an ideal species for addressing many of the challenges of climate change and variability, the ability to effectively apply prescribed burning to an increasingly fragmented and urbanized landscape is a primary factor limiting the restoration of longleaf pine (Costanza et al. 2015). Without fire or some other way to suppress early stage longleaf pine competition, tree regeneration is very difficult. ...
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The USDA Forest Service has many national level policies related to multiple use management. However, translating national policy to stand level forest management can be difficult. As an example of how a national policy can be put into action, we examined three case studies in which a desired future condition is evaluated at the national, region, and local scale. We chose to use carbon sequestration as the desired future condition because climate change has become a major area of concern during the last decade. Several studies have determined that the 193 million acres of US national forest land currently sequester 11 to 15% of the total carbon emitted as a nation. This paper provides a framework by which national scale strategies for maintaining or enhancing forest carbon sequestration is translated through regional considerations and local constraints in adaptive management practices. Although this framework used the carbon sequestration as a case study, this framework could be used with other national level priorities such as the National Environmental Protection Act (NEPA) or the Endangered Species Act (ESA).
... STSMs have been applied to a wide range of questions and ecological systems (Kerns et al., 2012;Wilson et al., 2014), including forested landscapes (e.g. Costanza et al., 2015;Miller et al., 2015;Costanza et al., 2017). Because of their general, empirical approach for representing vegetation dynamics, along with their inherent representation of stochasticity, STSMs offer the prospect of developing scenario-based simulation models that remain true to a forest planning model's assumptions of forest dynamics. ...
... We also acknowledge that the future effects of climate change on Bachman's sparrow distribution remains uncertain, however, current evidence suggests their range has not moved northward as other species have shifted (Hitch and Leberg, 2007). Other evidence suggests urban growth effects will far outweigh an increase in wildfires due to climate change in the southeastern United States (Costanza et al., 2015). ...
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A landscape-scale perspective on restoration ecology has been advocated, but few studies have informed restoration with landscape metrics or addressed broad-scale threats. Threats such as urban growth may affect restoration effectiveness in a landscape context. Here, we studied longleaf pine savanna in the rapidly urbanizing southeastern United States where a habitat-specialist bird, Bachman's sparrow (Peucaea aestivalis), is closely associated with savanna vegetation structure and frequent fire. Our objectives were to construct a species distribution model for Bachman's sparrow, determine the relationship between fire and urbanization, quantify the urban growth effect (2010–2090), identify potential restoration areas, and determine the interaction between restoration potential and urban growth by 2050. Number of patches, patch size, and isolation metrics were used to evaluate scenarios. The species distribution model was 88% accurate and emphasized multiscale canopy cover characteristics, fire, and percent habitat. Fires were less common <600 m from urban areas, and this fire suppression effect exacerbated urban growth effects. For restoration scenarios, canopy cover reduction by 30% resulted in nearly double the amount of habitat compared to the prescribed fire scenario; canopy cover reduction resulted in larger patch sizes and less patch isolation compared to current conditions. The effect of urban growth on restoration scenarios was unequal. Seventy-four percent of restoration areas from the prescribed fire scenario overlapped with projected urban growth, whereas the canopy cover reduction scenario only overlapped by 9%. We emphasize the benefits of simultaneously considering the effects of urban growth and landscape-scale restoration potential to promote a landscape with greater patch sizes and less isolation.
... Managers should identify possible pathways to collapse so as to hedge against the risk of this occurring. Identifying such pathways can be based on the current understanding of ecosystems or as an extension of available conceptual models and/or state-and-transition models (eg those provided by Perry and Enright [2002] and Costanza et al. [2015]). Models of ecosystem collapse should incorporate long-term scenarios that specifically acknowledge possible future disturbances and stressors that could trigger major, undesirable changes (Bowman et al. 2013;Messier et al. 2015). ...
Article
Many forest ecosystems are thought to be at risk of ecological collapse, which is broadly defined as an abrupt, long-lasting, and widespread change in ecosystem state and dynamics that has major negative impacts on biodiversity and key ecosystem services. However, there is currently a limited ability to accurately predict the risk of collapse for a given forest ecosystem. Moreover, how ecosystem collapse manifests itself will be ecosystem specific, as will be the associated mitigation strategies. In light of these challenges, we present a checklist of 11 practical principles to help managers reduce the risk of ecosystem collapse. These principles include developing a robust definition of collapse that is appropriate for a given ecosystem, managing for multiple ecosystem stressors under increasing uncertainty, adopting conservative approaches to management that account for potential losses of timber resources and limit the risk of overharvesting, and conducting long-term monitoring to gather data on key ecosystem attributes sensitive to ecological change.
... Some studies clearly indicate the effect of urbanization processes in combination to other drivers of change on biodiversity. Costanza, Terando, McKerrow & Collazo (2015) conducted a scenario analysis of the impacts of climate change, urbanization and management on future dynamics of the longleaf pine ecosystem. They clearly demonstrated the importance of accounting for multiple ecosystem drivers together for informing ecosystem management. ...
... This active and passive fire suppression has resulted in much less frequent fire return intervals compared to pre-European settlement conditions. Costanza et al. [2015], for example, examined wildfire records for the coastal plain regions of Alabama, Georgia, and Florida and found wildfire return intervals that ranged from ~40 yr for surface fires in early succession longleaf pine forests to over 100 yr in degraded sites. Although wildfire return intervals are now much longer resulting in less area burned across the landscape, the peak fire season still occurs in the spring ( Fig. 16.1) when large amounts of fine dead fuels (such as grasses and pine needles) from the previous winter are present and when humidity levels are low. ...
Chapter
Human-caused climate change is predicted to affect the frequency of hazard-linked extremes. Unusually large wildfires are a type of extreme event that is constrained by climate and can be a hazard to society but also an important ecological disturbance. This chapter focuses on changes in the frequency of extreme monthly area burned by wildfires for the end of the 21st century for a wildfire-prone region in the southeast United States. Predicting changes in area burned is complicated by the large and varied uncertainties in how the climate will change and in the models used to predict those changes. The chapter characterizes and quantifies multiple sources of uncertainty and propagate the expanded prediction intervals of future area burned. It illustrates that while accounting for multiple sources of uncertainty in global change science problems is a difficult task, it will be necessary in order to properly assess the risk of increased exposure to these society-relevant events.
... >10 6 cells) landscapes (e.g. Costanza et al. 2015b). Finally, ST-Sim users can integrate external models (e.g. ...
Article
A wide range of spatially explicit simulation models have been developed to forecast landscape dynamics, including models for projecting changes in both vegetation and land use. While these models have generally been developed as separate applications, each with a separate purpose and audience, they share many common features. We present a general framework, called a state-and-transition simulation model (STSM), which captures a number of these common features, accompanied by a software product, called ST-Sim, to build and run such models. The STSM method divides a landscape into a set of discrete spatial units and simulates the discrete state of each cell forward as a discrete-time-inhomogeneous stochastic process. The method differs from a spatially interacting Markov chain in several important ways, including the ability to add discrete counters such as age and time-since-transition as state variables, to specify one-step transition rates as either probabilities or target areas, and to represent multiple types of transitions between pairs of states. We demonstrate the STSM method using a model of land-use/land-cover (LULC) change for the state of Hawai'i, USA. Processes represented in this example include expansion/contraction of agricultural lands, urbanization, wildfire, shrub encroachment into grassland and harvest of tree plantations; the model also projects shifts in moisture zones due to climate change. Key model output includes projections of the future spatial and temporal distribution of LULC classes and moisture zones across the landscape over the next 50 years. State-and-transition simulation models can be applied to a wide range of landscapes, including questions of both land-use change and vegetation dynamics. Because the method is inherently stochastic, it is well suited for characterizing uncertainty in model projections. When combined with the ST-Sim software, STSMs offer a simple yet powerful means for developing a wide range of models of landscape dynamics.
... Climate change has obvious and direct effects on agricultural production. Accordingly, concerns about the possible impacts of climatic variability on agriculture have considerably changed research interests over the last decade (Adenle et al., 2015; Archie et al., 2014; Costanza et al., 2015; Demuzere et al., 2014; ElKhoury et al., 2015; Fu et al., 2015; Lindner et al., 2014; Paroissien et al., 2015; Qu and Silva, 2015; Shih et al., 2015). It is widely accepted that global climate change (GCC) may alter the production and productivity of agricultural crops; therefore, it is necessary to understand the possible impacts of GCC on agriculture. ...
... After researchers define their states, initial conditions, transitions, and pathways, they then use Monte Carlo simulations to measure the variability of the results that account for the stochastic properties of the model parameters. More complex models will include multiple scenarios that capture different management protocols [2], climate scenarios [3,4,5], state-and-transition attribute values (i.e., aggregating state classes and transitions to obtain different output summaries), various types of multipliers (e.g., the influence of slope on fire spread properties [6]), and stock-flow models (e.g., Intergovernmental Panel on Climate Change carbon models [7]). Although not required, STSM may also incorporate Geographic Information Systems (GIS) data of state classes, management zones, biophysical strata, and transitions. ...
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State-and-transition simulation modeling relies on knowledge of vegetation composition and structure (states) that describe community conditions, mechanistic feedbacks such as fire that can affect vegetation establishment, and ecological processes that drive community conditions as well as the transitions between these states. However, as the need for modeling larger and more complex landscapes increase, a more advanced awareness of computing resources becomes essential. The objectives of this study include identifying challenges of executing state-and-transition simulation models, identifying common bottlenecks of computing resources, developing a workflow and software that enable parallel processing of Monte Carlo simulations, and identifying the advantages and disadvantages of different computing resources. To address these objectives, this study used the ApexRMS® SyncroSim software and embarrassingly parallel tasks of Monte Carlo simulations on a single multicore computer and on distributed computing systems. The results demonstrated that state-and-transition simulation models scale best in distributed computing environments, such as high-throughput and high-performance computing, because these environments disseminate the workloads across many compute nodes, thereby supporting analysis of larger landscapes, higher spatial resolution vegetation products, and more complex models. Using a case study and five different computing environments, the top result (high-throughput computing versus serial computations) indicated an approximate 96.6% decrease of computing time. With a single, multicore compute node (bottom result), the computing time indicated an 81.8% decrease relative to using serial computations. These results provide insight into the tradeoffs of using different computing resources when research necessitates advanced integration of ecoinformatics incorporating large and complicated data inputs and models.
... We modified the LANDFIRE model pathways in several important ways to reflect current conditions and forest biomass production scenarios. First, we reduced wildfire probabilities for every vegetation type by 93% to reflect contemporary fire suppression in the Southeast following our other recent work [35] by adding a multiplier of 0.07 for every wildfire transition in all pathways. For models of forested vegetation types, we added states and transitions to represent harvest and thinning (See Figure 2 for an example, and Supplementary Material for all model state classes and transitions). ...
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We linked state-and-transition simulation models (STSMs) with an economics-based timber supply model to examine landscape dynamics in North Carolina through 2050 for three scenarios of forest biomass production. Forest biomass could be an important source of renewable energy in the future, but there is currently much uncertainty about how biomass production would impact landscapes. In the southeastern US, if forests become important sources of biomass for bioenergy, we expect increased land-use change and forest management. STSMs are ideal for simulating these landscape changes, but the amounts of change will depend on drivers such as timber prices and demand for forest land, which are best captured with forest economic models. We first developed state-and-transition model pathways in the ST-Sim software platform for 49 vegetation and land-use types that incorporated each expected type of landscape change. Next, for the three biomass production scenarios, the SubRegional Timber Supply Model (SRTS) was used to determine the annual areas of thinning and harvest in five broad forest types, as well as annual areas converted among those forest types, agricultural, and urban lands. The SRTS output was used to define area targets for STSMs in ST-Sim under two scenarios of biomass production and one baseline, business-as-usual scenario. We show that ST-Sim output matched SRTS targets in most cases. Landscape dynamics results indicate that, compared with the baseline scenario, forest biomass production leads to more forest and, specifically, more intensively managed forest on the landscape by 2050. Thus, the STSMs, informed by forest economics models, provide important information about potential landscape effects of bioenergy production.
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Context Both anthropogenic change and environmental variability cause spatiotemporal fluctuations in the availability of habitat on a landscape. Land acquisition and restoration for conservation also facilitates dynamic habitat accessibility. Accounting for these spatiotemporal dynamics is critical to the success of conservation planning to increase landscape connectivity. Objectives We aimed to forecast the individual and interactive effects of anthropogenic change, environmental variability, and conservation action on landscape connectivity over time. In doing so, we sought to evaluate the capacity of conservation actions intended to enhance connectivity to keep pace with global change. Methods We used a landscape change model to simulate strategies for the expansion of protected area networks on a ~1.5 million ha landscape in North Carolina. We forecasted spatiotemporal changes (2020-2100) to complex habitat networks across multiple scenarios of climate and land-use change, using graph theory to assess the variance in connectivity between conservation strategies and among global change futures. Results Both climate and land-use change reduced the influence of conservation on landscape connectivity, but through different mechanisms. Climate change increased available longleaf pine habitat, improving overall landscape connectivity and camouflaging connectivity improvements from conservation. Land-use change reduced the connectivity improvements facilitated by conservation as the cost of movement between habitat patches increased. Conclusion Rather than acting synergistically with land-use change, climate change negated the connectivity declines from land-use change in the study area. More broadly, our approach to forecast landscape-level responses to climate change, land-use change, and management can support the identification of conservation strategies that are more robust to global change, better enhancing landscape connectivity.
Article
Maintaining and enhancing landscape connectivity reduces biodiversity declines due to habitat fragmentation. Uncertainty remains, however, about the effectiveness of conservation for enhancing connectivity for multiple species on dynamic landscapes, especially over long time horizons. Focusing on central North Carolina, we forecast connectivity under four common conservation strategies‐ acquiring the lowest cost land, acquiring land clustered around already established conservation areas, acquiring land with high geodiversity characteristics, and acquiring land opportunistically‐ on a dynamic landscape incorporating forest growth and succession, disturbance, and management from 2020 to 2100. We used graph theoretic metrics to quantify landscape connectivity across these four strategies, evaluating connectivity for four ecologically relevant species guilds, representing endpoints along a spectrum of vagility and habitat specificity: long‐ vs. short‐distance dispersal ability and habitat specialists vs. generalists. Our results indicate that landscape connectivity will improve for specialist species under any conservation strategy employed, although these increases were highly variable across strategies. For generalist species, connectivity improvements were negligible. Overall, clustering the development of new protected areas around land already designated for conservation yielded the largest improvements in connectivity, with increases of several orders of magnitude beyond current landscape connectivity for both long‐ and short‐distance dispersing specialist species. Conserving the lowest cost land showed the smallest contributions to connectivity. Our approach provides insight into the connectivity contributions of a suite of conservation alternatives prior to on‐the‐ground implementation, and therefore can inform connectivity planning to maximize conservation benefit. This article is protected by copyright. All rights reserved
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Effective habitat conservation is predicated on maintaining high levels or increasing local persistence probability of the species it purports to protect. Thus, methodological approaches that improve the inferential value of local persistence are of utmost value to guide conservation planning as they inform area selection processes. Herein we used the painted bunting Passerina ciris, a species of conservation interest in North Carolina, as an illustrative case that combined single-season, single-species occupancy analyses and a threats and risk decision support tool to rank five areas of conservation interest in terms of local persistence probability. We used survey data from two seasons (2008–2009) grouped into 21 natal dispersal sampling units and land-cover data from 12 habitat classes to establish the relationship between local occupancy probability and habitat. Occupancy increased most strongly with increasing amount of maritime forest. Projections to year 2050, relative to year 2000, indicated that a potential loss of maritime forest of 200–1,300 ha, depending on the area of interest. Projected loss was lowest at Bald Head Island–Wilmington (2%) and highest at Camp Lejune (27%). Bald Head Island–Wilmington ranked highest in projected local persistence probability (0.91; 95% confidence interval [CI] ¼ 0.53–0.99), whereas Top Sail–Hammocks Beach Park ranked lowest (0.28; 95% CI ¼ 0.03–0.82). Estimates of local persistence offer decision-makers another criterion to prioritize areas for conservation and help guide efforts aimed at maintaining or enhancing local persistence. These include in situ habitat management, expanding or connecting existing areas of interest. In the future, we recommend the use of multiseason occupancy models, coupled with measures of uncertainty of land-cover projections, to strengthen inferences about local persistence, particularly useful in nonstationary landscapes driven by human activities.
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State-and-transition simulation models (STSMs) provide a general framework for forecasting landscape dynamics, including projections of both vegetation and land-use/land-cover (LULC) change. The STSM method divides a landscape into spatially-referenced cells and then simulates the state of each cell forward in time, as a discrete-time stochastic process using a Monte Carlo approach, in response to any number of possible transitions. A current limitation of the STSM method, however, is that all of the state variables must be discrete. 2.Here we present a new approach for extending a STSM, in order to account for continuous state variables, called a state-and-transition simulation model with stocks and flows (STSM-SF). The STSM-SF method allows for any number of continuous stocks to be defined for every spatial cell in the STSM, along with a suite of continuous flows specifying the rates at which stock levels change over time. The change in the level of each stock is then simulated forward in time, for each spatial cell, as a discrete-time stochastic process. The method differs from the traditional systems dynamics approach to stock-flow modelling in that the stocks and flows can be spatially-explicit, and the flows can be expressed as a function of the STSM states and transitions. 3.We demonstrate the STSM-SF method by integrating a spatially-explicit carbon
Technical Report
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Climate change impacts ecosystems in many ways, from effects on species to phenology to wildfire dynamics. Assessing the potential vulnerability of ecosystems to future changes in climate is an important first step in prioritizing and planning for conservation. Although assessments of climate change vulnerability commonly are done for species, fewer have been done for ecosystems. To aid regional conservation planning efforts, we assessed climate change vulnerability for ecosystems in the Southeastern United States and Caribbean. First, we solicited input from experts to create a list of candidate ecosystems for assessment. From that list, 12 ecosystems were selected for a vulnerability assessment that was based on a synthesis of available geographic information system (GIS) data and literature related to 3 components of vulnerability—sensitivity, exposure, and adaptive capacity. This literature and data synthesis comprised “Phase I” of the assessment. Sensitivity is the degree to which the species or processes in the ecosystem are affected by climate. Exposure is the likely future change in important climate and sea level variables. Adaptive capacity is the degree to which ecosystems can adjust to changing conditions. Where available, GIS data relevant to each of these components were used. For example, we summarized observed and projected climate, protected areas existing in 2011, projected sea-level rise, and projected urbanization across each ecosystem’s distribution. These summaries were supplemented with information in the literature, and a short narrative assessment was compiled for each ecosystem. We also summarized all information into a qualitative vulnerability rating for each ecosystem.
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This article explores factors that shape population structure in novel environments that have received scant theoretical attention: cities. Urban bird populations exhibit higher densities and lower diversity. Some work suggests this may result from lower predation pressure and more predictable and abundant resources. These factors may lead to populations with few winners and many losers regarding access to food, body condition, and reproductive success. We explore these hypotheses with an individual-energy-based competition model with two phenotypes of differing foraging ability. We show that low frequency resource fluctuations favor strong competitors and vice versa. We show that low predation skews equilibrium populations in favor of weak competitors and vice versa. Increasing the time between resource pulses can thus shift population structure from weak to strong competitor dominance. Given recent evidence for more constant resource input and lower predation in urban areas, the model helps understand observed urban bird population structure. r
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Multiagency partnerships increasingly work cooperatively to plan and implement fire management. The stakeholders that comprise such partnerships differ in their perceptions of the benefits and risks of fire use or nonuse. These differences inform how different stakeholders prioritize sites for burning, constrain prescribed burning, and how they rationalize these priorities and constraints. Using a survey of individuals involved in the planning and implementation of prescribed fire in the Onslow Bight region of North Carolina, we examined how the constraints and priorities for burning in the longleaf pine (Pinus palustris) ecosystem differed among three stakeholder groups: prescribed burn practitioners from agencies, practitioners from private companies, and nonpractitioners. Stakeholder groups did not differ in their perceptions of constraints to burning, and development near potentially burned sites was the most important constraint identified. The top criteria used by stakeholders to decide where to burn were the time since a site was last burned, and a site's ecosystem health, with preference given to recently burned sites in good health. Differences among stakeholder groups almost always pertained to perceptions of the nonecological impacts of burning. Prescribed burning priorities of the two groups of practitioners, and particularly practitioners from private companies, tended to be most influenced by nonecological impacts, especially through deprioritization of sites that have not been burned recently or are in the wildland-urban interface (WUI). Our results highlight the difficulty of burning these sites, despite widespread laws in the southeast U.S. that limit liability of prescribed burn practitioners. To avoid ecosystem degradation on sites that are challenging to burn, particularly those in the WUI, conservation partnerships can facilitate demonstration projects involving public and private burn practitioners on those sites. In summary, an increased understanding of stakeholder perspectives can provide insight into the potential long-term consequences of current fire management and thus facilitate effective ecosystem conservation.
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This state-of-knowledge review about the effects of fire on flora and fuels can assist land managers with ecosystem and fire management planning and in their efforts to inform others about the ecological role of fire. Chapter topics include fire regime classification, autecological effects of fire, fire regime characteristics and postfire plant community developments in ecosystems throughout the United States and Canada, global climate change, ecological principles of fire regimes, and practical considerations for managing fire in an ecosytem context.
Conference Paper
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The LANDFIRE program is developing 2010 maps of vegetation and wildland fuel attributes for the United States at 30-meter resolution. Currently available vegetation layers include ca. 2001 and 2008 forest canopy cover and canopy height derived from Landsat and Forest Inventory and Analysis (FIA) plot measurements. The LANDFIRE canopy cover layer for the conterminous United States is the first of its kind developed with FIA tree measurements as the source of ground reference data. The mapping process is based on regression tree models with FIA plot values as the dependent variables (canopy cover, canopy height), using predictor variables derived from reflectance, terrain, and a Shuttle Radar Topography Mission-based height metric. Base vegetation maps are updated beginning with a set of annual disturbance maps that combine extant fire severity mapping with Landsat time-series disturbance and polygon data describing management activities on Federal and state lands. FIA plot data are used in the Forest Vegetation Simulator to model disturbance effects on forest vegetation for each disturbance type and severity class. Updated 2010 products are scheduled for delivery during early 2013. The 2010 products include a new tree list layer in which stand structure is depicted explicitly by approximating a representative list of trees occurring at each 30-m pixel. The tree list layer provides a more detailed characterization of canopy fuel structure than is available with standard LANDFIRE products, facilitating new applications and research in fire behavior and fire effects simulation.
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The future health of ecosystems is arguably as dependent on urban sprawl as it is on human-caused climatic warming. Urban sprawl strongly impacts the urban ecosystems it creates and the natural and agro-ecosystems that it displaces and fragments. Here, we project urban sprawl changes for the next 50 years for the fast-growing Southeast U.S. Previous studies have focused on modeling population density, but the urban extent is arguably as important as population density per se in terms of its ecological and conservation impacts. We develop simulations using the SLEUTH urban growth model that complement population-driven models but focus on spatial pattern and extent. To better capture the reach of low-density suburban development, we extend the capabilities of SLEUTH by incorporating street-network information. Our simulations point to a future in which the extent of urbanization in the Southeast is projected to increase by 101% to 192%. Our results highlight areas where ecosystem fragmentation is likely, and serve as a benchmark to explore the challenging tradeoffs between ecosystem health, economic growth and cultural desires.
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Information on future land-use and land-cover (LULC) change is needed to analyze the impact of LULC change on ecological processes. The U.S. Geological Survey has produced spatially explicit, thematically detailed LULC projections for the conterminous United States. Four qualitative and quantitative scenarios of LULC change were developed, with characteristics consistent with the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES). The four quantified scenarios (A1B, A2, B1, and B2) served as input to the Forecasting Scenarios of Land-use Change (FORE-SCE) model. Four spatially explicit datasets consistent with scenario storylines were produced for the conterminous United States, with annual LULC maps from 1992 through 2100. The future projections are characterized by a loss of natural land covers in most scenarios, with corresponding expansion of anthropogenic land uses. Along with the loss of natural land covers, remaining natural land covers experience increased fragmentation under most scenarios, with only the B2 scenario remaining relatively stable in both proportion of remaining natural land covers and basic fragmentation measures. Forest stand age was also modeled. By 2100, scenarios and ecoregions with heavy forest cutting have relatively lower mean stand ages compared to those with less forest cutting. Stand ages differ substantially between unprotected and protected forest lands, as well as between different forest classes. The modeled data were compared to the National Land Cover Database (NLCD) and other data sources to assess model characteristics. The consistent, spatially explicit, and thematically detailed LULC projections and the associated forest stand age data layers have been used to analyze LULC impacts on carbon and greenhouse gas fluxes, biodiversity, climate and weather variability, hydrologic change, and other ecological processes.
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The emerging field of climate-change adaptation has experienced a dramatic increase in attention as the impacts of climate change on biodiversity and ecosystems have become more evident. Preparing for and addressing these changes are now prominent themes in conservation and natural resource policy and practice. Adaptation increasingly is viewed as a way of managing change, rather than just maintaining existing conditions. There is also increasing recognition of the need not only to adjust management strategies in light of climate shifts, but to reassess and, as needed, modify underlying conservation goals. Major advances in the development of climate-adaptation principles, strategies, and planning processes have occurred over the past few years, although implementation of adaptation plans continues to lag. With ecosystems expected to undergo continuing climate-mediated changes for years to come, adaptation can best be thought of as an ongoing process, rather than as a fixed endpoint.
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With projected climate change, we expect to face much more forest fire in the coming decades. Policymakers are challenged not to categorize all fires as destructive to ecosystems simply because they have long flame lengths and kill most of the trees within the fire boundary. Ecological context matters: In some ecosystems, high-severity regimes are appropriate, but climate change may modify these fire regimes and ecosystems as well. Some undesirable impacts may be avoided or reduced through global strategies, as well as distinct strategies based on a forest’s historical fire regime.
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This study used a wildfire loss simulation model to evaluate how different land use policies are likely to influence wildfire risk in the wildland urban interface (WUI) for Flathead County, Montana. The model accounts for the complex socio-ecological interactions among climate change, economic growth, land use change and policy, homeowner mitigations, and forest treatments in Flathead County's WUI over the five 10-year subperiods comprising the future evaluation period (i.e., 2010-2059). Wildfire risk, defined as expected residential losses from wildfire [E(RLW)], depends on the number of residential properties on parcels, the probability that parcels burn, the probability of wildfire losses to residential structures on properties given the parcels on which those properties are located burn, the average percentage of wildfire-related losses in aesthetic values of residential properties, and the total value (structures plus land) of residential properties. E(RLW) for the five subperiods is simulated for 2010 (referred to as the current), moderately restrictive, and highly restrictive land use policy scenarios, a moderate economic growth scenario and the A2 greenhouse gas emissions scenario. Results demonstrate that increasingly restrictive land use policy for Flathead County significantly reduces the amount and footprint of future residential development in the WUI. In addition, shifting from the current to a moderately restrictive land use policy for Flathead County significantly reduces wildfire risk for the WUI, but shifting from the current to a highly restrictive land use policy does not significantly reduce wildfire risk in the WUI. Both the methods and results of the study can help land and wildfire managers to better manage future wildfire risk and identify residential areas having potentially high wildfire risk.
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At their worst, fires at the rural-urban or wildland-urban interface cause tragic loss of human lives and homes, but mitigating these fire effects through management elicits many social and scientific challenges. This paper addresses four interconnected management challenges posed by socially disastrous landscape fires. The issues concern various assets (particularly houses, human life and biodiversity), fuel treatments, and fire and human behaviours. The topics considered are: 'asset protection zones'; 'defensible space' and urban fire spread in relation to house ignition and loss; 'stay-or-go' policy and the prediction of time available for safe egress and the possible conflict between the creation of defensible space and wildland management objectives. The first scientific challenge is to model the effective width of an asset protection zone of an urban area. The second is to consider the effect of vegetation around a house, potentially defensible space, on fire arrival at the structure. The third scientific challenge is to present stakeholders with accurate information on rates of spread, and where the fire front is located, so as to allow them to plan safe egress or preparation time in their particular circumstances. The fourth scientific challenge is to be able to predict the effects of fires on wildland species composition. Associated with each scientific challenge is a social challenge: for the first two scientific challenges the social challenge is to co-ordinate fuel management within and between the urban and rural or wildland sides of the interface. For the third scientific challenge, the social challenge is to be aware of, and appropriately use, fire danger information so that the potential for safe egress from a home can be estimated most accurately. Finally, the fourth social challenge is to for local residents of wildland-urban interfaces with an interest in biodiversity conservation to understand the effects of fire regimes on biodiversity, thereby assisting hard-pressed wildland managers to make informed choices.
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In forests historically maintained by frequent fire, reintroducing fire after decades of exclusion often causes widespread overstory mortality. To better understand this phenomenon, we subjected 16 fire-excluded (ca. 40 years since fire) 10 ha longleaf pine (Pinus palustris Mill.) stands to one of four replicated burning treatments based on volumetric duff moisture content (VDMC): wet (115% VDMC); moist (85% VDMC); dry (55% VDMC); and a no-burn control. During the first 2 years postfire, overstory pines in the dry burns suffered the greatest mortality (mean 20.5%); pine mortality in the wet and moist treatments did not differ from the control treatment. Duff reduction was greatest in the dry burns (mean 46.5%), with minimal reduction in the moist and wet burns (14.5% and 5%, respectively). Nested logistic regression using trees from all treatments revealed that the best predictors of individual pine mortality were duff consumption and crown scorch (P < 0.001; R2 = 0.34). Crown scorch was significant only in dry burns, whereas duff consumption was significant across all treatments. Duff consumption was related to moisture content in lower duff (Oa; R2 = 0.78, P < 0.001). Restoring fire to long-unburned forests will require development of burn prescriptions that include file effects of duff consumption, an often overlooked fire effect.
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Studies of the effects of climate change on forests have focused on the ability of species to tolerate temperature and moisture changes and to disperse, but they have ignored the effects of disturbances caused by climate change (e.g., Ojima et al. 1991).Yet modeling studies indicate the importance of climate effects on disturbance regimes (He et al. 1999). Local, regional, and global changes in temperature and precipitation can influence the occurrence, timing, frequency, duration, extent, and intensity of disturbances (Baker 1995, Turner et al. 1998). Because trees can survive from decades to centuries and take years to become established, climate-change impacts are expressed in forests, in part, through alterations in disturbance regimes (Franklin et al. 1992, Dale et al. 2000). yes
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Southern old-growth forests are small and rare, but critical in their support of biodiversity. While the remnant old-growth forests contain diversity that is significant regionally and globally, they most likely represent only a portion of the variety that old forests once sustained. High within-habitat diversity and rarity in the landscape magnify the conservation value of these systems. Old-growth stands of two particular communities—longleaf pine (Pinus palustris) forests and floodplain (bottomland/swamp) forests—have emblematic links to two notable bird species of concern, the Red-cockaded (Picoides borealis) and Ivory-billed (Campephilus principalis) Woodpeckers. In addition to conservation importance, southern old forests have social and economic values that are in danger of further impoverishment if these systems are lost to future generations. Summarizing the findings from a recenatus and values, identify current threats, and describe potential strategies to promote greater long-term conservation of old forests across the South.
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Biologically rich savannas and woodlands dominated by Pinus palustris once dominated the southeastern U.S. landscape. With European settlement, fire suppression, and landscape fragmentation, this ecosystem has been reduced in area by 97%. Half of remnant forests are not burned with sufficient frequency, leading to declines in plant and animal species richness. For these fire-suppressed ecosystems a major regional conservation goal has been ecological restoration, primarily through the reinitiation of historic fire regimes. Unfortunately, fire reintroduction in long-unburned Longleaf pine stands can have novel, undesirable effects. We review case studies of Longleaf pine ecosystem restoration, highlighting novel fire behavior, patterns of tree mortality, and unintended outcomes resulting from reintroduction of fire. Many of these pineland restoration efforts have resulted in excessive overstory pine mortality (often >50%) and produced substantial quantities of noxious smoke. The most compelling mechanisms of high tree mortality after reintroduction of fire are related to smoldering combustion of surface layers of organic matter (duff) around the bases of old pines. Development of effective methods to reduce fuels and competing vegetation while encouraging native vegetation is a restoration challenge common to fire-prone ecosystems worldwide that will require understanding of the responses of altered ecosystems to the resumption of historically natural disturbances.
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When Europeans first settled in southeastern North America and began to explore their new homeland, they found a landscape that was to a large extent dominated by open, savannalike longleaf pine woodlands. The pines were typically widely spaced, affording the traveler opportunities to see for long distances without obstruction by undergrowth. The ground layer was dominated by grasses with a great diversity of showy forbs. Vegetation of this character occurred from southeastern Virginia southward deep into peninsular Florida and west to western Louisiana and eastern Texas (Frost et al. 1986; Harcombe et al. 1993; Peet and Allard 1993; Ware et al. 1993; Platt 1999; Christensen 2000; Frost this volume).
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LANDFIRE is a 5-year, multipartner project producing consistent and comprehensive maps and data describ-ing vegetation, wildland fuel, fire regimes and ecological departure from historical conditions across the United States. It is a shared project between the wildland fire management and research and development programs of the US Depart-ment of Agriculture Forest Service and US Department of the Interior. LANDFIRE meets agency and partner needs for comprehensive, integrated data to support landscape-level fire management planning and prioritization, commu-nity and firefighter protection, effective resource allocation, and collaboration between agencies and the public. The LANDFIRE data production framework is interdisciplinary, science-based and fully repeatable, and integrates many geospatial technologies including biophysical gradient analyses, remote sensing, vegetation modelling, ecological simu-lation, and landscape disturbance and successional modelling. LANDFIRE data products are created as 30-m raster grids and are available over the internet at www.landfire.gov, accessed 22 April 2009. The data products are produced at scales that may be useful for prioritizing and planning individual hazardous fuel reduction and ecosystem restoration projects; however, the applicability of data products varies by location and specific use, and products may need to be adjusted by local users.
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Book
The longleaf pine ecosystem, once one of the most extensive ecosystems in North America, is now among the most threatened. Over the past few centuries, land clearing, logging, fire suppression, and the encroachment of more aggressive plants have led to an overwhelming decrease in the ecosystem’s size, to approximately 2.2% of its original coverage. Despite this devastation, the range of the longleaf still extends from Virginia to Texas. Through the combined efforts of organizations such as the USDA Forest Service, the Longleaf Alliance, and the Nature Conservancy, extensive programs to conserve, restore, and manage the ecosystem are currently underway. The longleaf pine ecosystem is valued not only for its aesthetic appeal, but also for its outstanding biodiversity, habitat value, and for the quality of the longleaf pine lumber. It has a natural resistance to fire and insects, and supports more than thirty threatened or endangered plant and animal species, including the red-cockaded woodpecker and the gopher tortoise. The Longleaf Pine Ecosystem unites a wealth of current information on the ecology, silviculture, and restoration of this ecosystem. The book also includes a discussion of the significant historical, social, and political aspects of ecosystem management, making it a valuable resource for students, land managers, ecologists, private landowners, government agencies, consultants, and the forest products industry. About the Editors: Dr. Shibu Jose is Associate Professor of Forest Ecology and Dr. Eric J. Jokela is Professor of Silviculture at the School of Forest Resources and Conservation at the University of Florida in Gainesville. Dr. Deborah L. Miller is Associate Professor of Wildlife Ecology in the Department of Wildlife Ecology and Conservation at the University of Florida in Milton.
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Significant climate anomalies have characterized the last 1000 yr in the Sierra Nevada, California, USA. Two warm, dry periods of 150- and 200-yr duration occurred during AD 900-1350, which were followed by anomalously cold climates, known as the Little Ice Age, that lasted from AD 1400 to 1900. Climate in the last century has been significantly warmer. Regional biotic and physical response to these climatic periods occurred. Climate variability presents challenges when interpreting historical variability, including the need to accommodate climate effects when comparing current ecosystems to historical conditions, especially if comparisons are done to evaluate causes (e.g., human impacts) of differences, or to develop models for restoration of current ecosystems. Many historical studies focus on "presettlement" periods, which usually fall within the Little Ice Age. Thus, it should be assumed that ecosystems inferred for these historical periods responded to different climates than those at present, and management implications should be adjusted accordingly. The warmer centuries before the Little Ice Age may be a more appropriate analogue to the present, although no historic period is likely to be better as a model than an understanding of what conditions would be at present without intervention. Understanding the climate context of historical reconstruction studies, and adjusting implications to the present, should strengthen the value of historical variability research to management.
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The asynchronous regional regression model (ARRM) is a flexible and computationally efficient statistical model that can downscale station‐based or gridded daily values of any variable that can be transformed into an approximately symmetric distribution and for which a large‐scale predictor exists. This technique was developed to bridge the gap between large‐scale outputs from atmosphere–ocean general circulation models (AOGCMs) and the fine‐scale output required for local and regional climate impact assessments. ARRM uses piecewise regression to quantify the relationship between observed and modelled quantiles and then downscale future projections. Here, we evaluate the performance of three successive versions of the model in downscaling daily minimum and maximum temperature and precipitation for 20 stations in North America from diverse climate zones. Using cross‐validation to maximize the independent comparison period, historical downscaled simulations are evaluated relative to observations in terms of three different quantities: the probability distributions, giving a visual image of the skill of each model; root‐mean‐square errors; and bias in nine quantiles that represent both means and extremes. Successive versions of the model show improved accuracy in simulating extremes, where AOGCMs are often most biased and which are frequently the focus of impact studies. Overall, the quantile regression‐based technique is shown to be efficient, robust, and highly generalizable across multiple variables, regions, and climate model inputs.
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Ecosystems around the world are already threatened by land-use and land-cover change, extraction of natural resources, biological disturbances, and pollution. These environmental stressors have been the primary source of ecosystem degradation to date, and climate change is now exacerbating some of their effects. Ecosystems already under stress are likely to have more rapid and acute reactions to climate change; it is therefore useful to understand how multiple stresses will interact, especially as the magnitude of climate change increases. Understanding these interactions could be critically important in the design of climate adaptation strategies, especially because actions taken by other sectors (eg energy, agriculture, transportation) to address climate change may create new ecosystem stresses.
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A field study was installed to test silvicultural treatments for establishing longleaf pine (Pinus palustris Mill.) in loblolly pine (P. taeda L.) stands. Harvesting was used to create seven canopy treatments, four with uniformly distributed canopies at different residual basal areas [Control (16.2 m2/ha), MedBA (9.0 m2/ha), LowBA (6.4 m2/ha), and Clearcut (0 m2/ha)] and three circular gaps defined by area [LG (∼5281 m2), MG (∼3217 m2), and SG (∼1576 m2)]. Within each canopy treatment, we applied three cultural treatments designed to benefit planted seedling early growth: no treatment (NT), herbicide (H), and herbicide plus fertilization (H + F). Three growing seasons after planting, seedling survival significantly differed among canopy treatments; compared to Controls, Clearcut plots had higher survival (80.6%). H and H + F treatments did not affect seedling survival in the first two years after application. Canopy removal generally increased seedling root collar diameter (RCD) but interacted with cultural treatments. NT within Controls had the smallest RCD, and H + F within Clearcuts had the largest RCD. Canopy treatments significantly affected the percentage of seedlings in height growth (i.e., terminal bud >15 cm high); Control plots had a significantly lower percentage of seedlings in height growth than other canopy treatments. H and H + F treatments also significantly increased the percentage of seedlings in height growth when compared to NT. Our results indicate that canopy removal improves early establishment of longleaf pine seedlings and that herbicides may additionally be used to increase early longleaf pine seedling growth. Our results are similar to those reported in previous studies conducted in mature longleaf pine stands.
Article
The hallmark of development in the United States has been sprawling urbanisation. However, most of the analyses about urbanisation have focused on specific regions or metropolitan areas. This study provides a comprehensive overview of the changing urban landscape patterns between 2001 and 2006. Using the land cover data from the US Geological Survey for these 2 years, I characterise the landscape metrics for each county in the continental United States. The changes in these metrics are correlated with the drivers of urbanisation including socioeconomic variables. Uneven and heterogeneous patterns of growth in a country this large are not surprising. However, the metrics reveal that while urban counties are becoming less fragmented, some rural counties in the Southern and Western United States are experiencing significant leapfrog development.
Article
Scientifically informed conservation goals do not always align with what is accomplished in practice, leading to the so-called “knowing–doing gap”. One reason why the knowing–doing gap exists may be that scientific recommendations often do not account for the “real-world” social context of conservation. The social context may be particularly important for ecosystem restoration involving prescribed burning. In the longleaf pine ecosystem, scientists and conservationists have called for large-scale restoration using prescribed burning; however, recent levels of burning may be insufficient to accomplish restoration. We studied the knowing–doing gap in the longleaf pine ecosystem by investigating where recent burns had been conducted. We used spatio-temporal logistic regression to relate recent burning in the Onslow Bight, North Carolina, to site and landscape attributes that burn practitioners there had previously said were important. Our results show that prescribed burns were preferentially placed on high-quality sites rather than on degraded sites, suggesting a knowing–doing gap in longleaf pine conservation in which burning is not used for restoration. In addition, sites that had not been burned for at least 4 years showed an increased probability of burning as distance from development increased, suggesting that sites with high fuel loads near development were not likely to be burned. Finding ways to encourage burning on degraded sites near development, such as rewarding practitioners for successfully conducting difficult burns, would help narrow the knowing–doing gap in conservation of this and other fire-dependent ecosystems.
Article
Restoration is a time-consuming and expensive endeavour. As such, it is a field that could benefit immensely from the adoption of an adaptive management approach, where knowledge gained from previous experiences is incorporated into future planning efforts. However, meta-analyses that synthesise results obtained over large spatial scales are rarely conducted, hindering the ability of restoration practitioners to learn from mistakes and successes of others. We present a case study of groundcover restoration in the southeastern United States as an example of the wealth of information that can be obtained from a synthesis of existing data. This example is characteristic of many restoration endeavours in that a large number of decisions must be made during the restoration process. We used Classification and Regression Trees (CART) to identify those restoration activities that most often lead to successful groundcover establishment in forests of the Southeastern US. The most important factors in determining mean survivorship of plants established through outplanting included planting season, the presence of existing canopy cover, and the use of prescribed fire after planting. These three factors alone explained 28% of the variation in mean survivorship (pPRE=0.28, model PRE=0.32). In contrast, the single greatest predictive variable in the establishment density of seeds sown on restoration sites was the use of herbicide prior to planting which explained 30% of the variation in establishment rate (pPRE=0.30, model PRE=0.38). Based on these analyses, we describe simple, discrete recommendations that should improve the survival and establishment of native plant species in restoration sites across the southeastern coastal plain of the US. We also discuss the utility of CART in distilling large volumes of existing data into easily interpretable recommendations.
Article
a b s t r a c t Longleaf pine (Pinus palustris Mill.), a species that once dominated the southeastern USA, is considered to be more drought tolerant than the principle plantation species in the South, loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.), and so is predicted to better cope with increases in drought fre-quency associated with climate change. To determine if longleaf pine displays a more conservative water use strategy than the other two southern pine species, we examined diurnal patterns in leaf light-satu-rated photosynthesis, stomatal conductance, water use efficiency and leaf water potential (W L) over one growing season in a 50-year-old replicated field experiment. Short-term photosynthetic response to tem-perature was examined in August. No consistent differences among species in leaf gas exchange rates were observed, but W L was higher in longleaf pine compared to loblolly and slash pine across the growing season. Foliar d 13 C measured at the end of the growing season was higher in longleaf pine than in loblolly pine but not slash pine. No temperature optimum of photosynthesis was observed in any species and photosynthesis did not respond to changing temperature. Based on leaf physiological traits, these results do not support the contention that longleaf pine has a more conservative leaf water use strategy than the other two pine species. The results do suggest that differences in hydraulic architecture or hydraulic effi-ciency may account for higher W L and perhaps greater drought tolerance in longleaf pine.
Book
IPCC Special Report on Emissions Scenarios Contents: Foreword Preface Summary for policymakers Technical Summary Chapter 1: Background and Overview Chapter 2: An Overview of the Scenario Literature Chapter 3: Scenario Driving Forces Chapter 4: An Overview of Scenarios Chapter 5: Emission Scenarios Chapter 6: Summary Discussions and Recommendations
Article
The results of a survey of fire management officials concerning historical and projected prescribed burning activity in the South is reported. Prescribed burning programs on USDA Forest Service and private and state-owned lands are described in terms of area burned by ownership and state, intended resource benefits, barriers to expanded burning, and optimum burning area needed to achieve resource management goals. More than 4.1 million ac/yr of pine-type forest were burned between 1985 and 1994, about 6.5% of the area in pine-type forest per year. South. J. Appl. For. 25(4):149–153.
Article
a b s t r a c t We developed a spatially explicit model that simulated future southern pine beetle (Dendroctonus frontalis, SPB) dynamics and pine forest management for a real landscape over 60 years to inform regional forest management. The SPB has a considerable effect on forest dynamics in the Southeastern United States, especially in loblolly pine (Pinus taeda) stands that are managed for timber production. Regional outbreaks of SPB occur in bursts resulting in elimination of entire stands and major economic loss. These outbreaks are often interspersed with decades of inactivity, making long-term modeling of SPB dynam-ics challenging. Forest management techniques, including thinning, have proven effective and are often recommended as a way to prevent SPB attack, yet the robustness of current management practices to long-term SPB dynamics has not been examined. We used data from previously documented SPB infesta-tions and forest inventory data to model four scenarios of SPB dynamics and pine forest management. We incorporated two levels of beetle pressure: a background low level, and a higher level in which SPB had the potential to spread among pine stands. For each level of beetle pressure, we modeled two scenarios of forest management: one assuming forests would be managed continuously via thinning, and one with a reduction in thinning. For our study area in Georgia, Florida, and Alabama, we found that beetle pressure and forest management both influenced the landscape effects of SPB. Under increased SPB pressure, even with continuous management, the area of pine forests affected across the region was six times greater than under baseline SPB levels. However, under high SPB pressure, continuous management decreased the area affected by nearly half compared with reduced management. By incorporating a range of forest and SPB dynamics over long time scales, our results extend previous modeling studies, and inform for-est managers and policy-makers about the potential future effects of SPB. Our model can also be used to investigate the effects of additional scenarios on SPB dynamics, such as alternative management or climate change.
Article
A study was conducted on a Coastal Plain flatwoods site in Florida to determine the effects of common forestry herbicides on Longleaf pine seedling survival and growth and on the understory vegetation. Following removal of the overstory slash pine, five low-rate herbicide treatments were applied over the top of planted Longleaf pine seedlings to provide short-term understory vegetation control and accelerate seedling growth. The objective was to increase Longleaf pine growth by reducing the shrub competition while increasing the herbaceous ground cover. Despite causing reduction in seedling survival over the control treatment, imazapyr (0.21 ae kg/ha) resulted in the highest seedling growth (height and volume). The significant reduction of shrub cover, density, and height by imazapyr was believed to be responsible for the improved seedling growth in this treatment. Both hexazinone (0.56 ai kg/ha) and sulfometuron methyl (0.26 ai kg/ha) + hexazinone (0.56 ai kg/ha) treatments also reduced cover of Runner oak, a major shrub species, but the response was evident only 8 months after treatment. Although sulfometuron methyl (0.26 ai kg/ha) and sulfometuron methyl + hexazinone treatments did not result in any significant change in overall grass, forb, and shrub cover, both treatments resulted in greater Longleaf pine growth compared to the control. None of the herbicides significantly affected the major understory grasses and forbs. Overall, imazapyr provided the best desired results with significant increase in seedling growth and better control of shrub species with no significant effects on grass and other herbaceous species cover.
Article
Aristida stricta (wiregrass), a perennial bunchgrass, quickly accumulates dead leaves, which along with the shed needles of Pinus palustris (longleaf pine) provide the fuel for frequent surface fires. Thus, historically, wiregrass played a key role in many longleaf communities where it significantly influenced the natural fire regime and thereby the composition of the plant community. Reestablishment of wiregrass is, therefore, critical to restoring the native understory of Atlantic Coastal Plain longleaf pine ecosystems. This study measured the effects of different site preparations and fertilizer application on the survival and growth of wiregrass seedlings. Two-month–old seedlings were underplanted in existing longleaf pine stands on dry Lakeland soils at the Savannah River Site in South Carolina. Survival was acceptable at 51% after four years, although reduced owing to drought and small seedling size. Survival and growth could both be increased by using older seedlings with an initial height of at least 6 cm. Wiregrass leaves grew quite rapidly and attained an average length of 48 cm in four years on control plots. Basal area growth rate was greater than expected, averaging 40% on control treatments and 55% on cultivated and fertilized plots. If growth rates during the first four seasons continue, wiregrass will attain mature size on cultivated and fertilized plots at six years, while non-fertilized control plots will take eight years. A planting density of one seedling per m2 is recommended to provide sufficient wiregrass foliar cover to influence fire regimes in a reasonable length of time (i.e., 5–7 years).
Article
The significant loss of the longleaf pine-wiregrass ecosystem in the southeastern United States has serious implications for biodiversity and ecosystem functioning. In response to this loss, we have initiated a long-term and landscape-scale restoration experiment at the 80,125 ha (310 mi2) Department of Energy Savannah River Site (SRS) located near Aiken, South Carolina. Aristida beyrichiana (wiregrass), an important and dominant grass (i.e., a “matrix” species) of the longleaf pine savanna understory, and 31 other herbaceous “non-matrix” species were planted at six locations throughout SRS in 2002 and 2003. Of the 36,056 transplanted seedlings, 75% were still alive in June 2004, while mean 1–2 year survival across all planted species was 48%. Lespedeza hirta (hairy lespedeza) exhibited the greatest overall survival per 3 × 3 m cell at 95%, whereas Schizachyrium spp. (little bluestem) exhibited the greatest mean cover among individual species at 5.9%. Wiregrass survival and cover were significantly reduced when planted with non-matrix species. Aggregate cover of all planted species in restored cells averaged 25.9% in 2006. High rates of survival and growth of the planted species resulted in greater species richness (SR), diversity, and vegetative cover in restored cells. Results suggest that the loss of the longleaf pine-wiregrass ecosystem may be ameliorated through restoration efforts and illustrate the positive impact of restoration plantings on biodiversity and vegetative cover.
Chapter
From Virginia to Texas, much of the coastal plain landscape was once covered by a “vast forest of the most stately pine trees that can be imagined … ”(Bartram 1791 [1955]). Longleaf pine could be found from sea level, on the margins of brackish marshes, to around 2000 feet on the Talladega National Forest in Alabama (Harper 1905; Stowe et al. 2002). The spectacular failure of the primeval longleaf pine forest (Fig. 1) to reproduce itself after exploitation is a milestone event in the natural history of the eastern United States, even greater in scale and impact than the elimination of chestnut (Castanea dentata) from Appalachian forests by blight. This chapter discusses presettlement extent and summarizes major events in the decline of the longleaf pine ecosystem and its displacement from more than 97% of the lands it once occupied.
Chapter
Restoring longleaf pine trees to the southeastern landscape is a daunting task, because more than 97% of the original area has been lost to other uses (Landers et al. 1995; Frost this volume). However, many of the disincentives and difficulties in managing for longleaf pine have been addressed and solved or exposed as misconceptions, and landowners across the region are expressing renewed interest in returning this once-dominant southern pine to their lands. Several recent publications providing information to landowners and natural resource managers on longleaf pine restoration and management have appeared (Earley 1997, 2002; Franklin 1997; Kush 1997, 1999, 2001, 2003; Johnson 1999; Mitchell et al. 2000).
Chapter
Regenerating longleaf pine (Pinus palustris) is key to its long-term sustainable production of forest resources and its perpetuation as the dominant tree species in a variety of important ecosystems ranging from xeric to mesic to hydric site conditions.
Article
The longleaf pine-grassland (Pinus palustris-Poaceae) ecosystem occupied over 30 million ha in the southeastern United States at the time of European discovery. Frequent low- to moderate-intensity surface fires ignited by both lightning and native Americans sustained open diverse stands in a fire climax and prevented succession to mixed hardwood forests. Disruption of pre-historical and historical fire regimes, coupled with land conversion, urbanization, and other factors, is responsible for the rapid decline of the ecosystem. Today only about 1.2 million ha remain, much in isolated fragments. Primarily because of habitat loss, many animal and plant species associated with longleaf forests are now rare or in decline. Restoration ecologists and managers face a daunting challenge—recreating an ecosystem, in the face of chronic cumulative stress from human activities, that varied widely over temporal and spatial scales. Key restoration factors include: (1) development of a general understanding of the historical condition of the longleaf ecosystem, especially unusual or unique communities and habitats embedded in the general fabric of the larger ecosystem, (2) initiation and expansion of a fire regime, where feasible, similar to that which historically shaped the ecosystem, (3) maintenance/enhancement of herbaceous diversity, (4) continued research on habitat requirements and distribution of rare species, and (5) encouragement of a multi-owner partnership approach to promote conservation across the landscape. Landowners and the public must be educated about the values of the longleaf pine-grassland ecosystem and develop a conservation ethic that considers aesthetics, wildlife, and biodiversity, in addition to economics, if the ecosystem is to be restored. Most forestry practices used to manage and restore longleaf forests are of low short-term risk to rare species in this ecosystem. The benefits of active management usually far outweigh the long-term risks associated with no management.
Article
Longleaf pine (Pinus palustris Mill.) forests of the Gulf Coastal Plain historically burned every 2–4 years with low intensity fires, which maintained open stands with herbaceous dominated understories. During the early and mid 20th century however, reduced fire frequency allowed fuel to accumulate and hardwoods to increase in the midstory and overstory layers, while woody shrubs gained understory dominance. In 2001, a research study was installed in southern Alabama to develop management options that could be used to reduce fuel loads and restore the ecosystem. As part of a nationwide fire and fire surrogates study, treatments included a control (no fire or other disturbance), prescribed burning only, thinning of selected trees, thinning plus prescribed burning, and herbicide plus prescribed burning. After two cycles of prescribed burning, applied biennially during the growing season, there were positive changes in ecosystem composition. Although thinning treatments produced revenue, while reducing midstory hardwoods and encouraging growth of a grassy understory, burning was needed to discourage regrowth of the hardwood midstory and woody understory. Herbicide application followed by burning gave the quickest changes in understory composition, but repeated applications of fire eventually produced the same results at the end of this 8-year study. Burning was found to be a critical component of any restoration treatment for longleaf communities of this region with positive changes in overstory, midstory and understory layers after just three or four burns applied every 2 or 3 years.
Article
Modeling can be used to resolve controversies generated by differing opinions about the effects of livestock grazing, fire management, and herbicide application on western public lands. We used spatial simulations of 10 potential vegetation types to compare 6 management scenarios over 20 years in a 141,853 ha landscape in eastern Nevada. Scenarios were compared by incrementally varying one factor at a time and were based on the Bureau of Land Management's (BLM's) potential restoration plans. The following factors were varied: managed fire, livestock grazing, mechanical and chemical treatment of vegetation, and restoration budgets. After 20 years the differences in vegetative composition between scenarios were small. BLM's level of funding was too low to improve ecological condition because the landscape was too degraded, however, current funding could maintain communities that retained native perennial understories. In general, the effects of livestock grazing were minor and undesirable compared to benefits gained from the use of mechanical and chemical methods followed by seeding. Mechanical methods and herbicide application in addition to current fire management had more desirable effects than without fire management.