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Location of the Klamath Ranger District among physiographic provinces of southwest Oregon. (Source is Franklin and Dyrness 1973.)
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Investigations using available data sought to guide short-term management decisions regarding the needs of northern spotted owl in the high Cascade Mountains of Oregon. Landscape attributes and pattern indices were measured and tested for identification of areas likely to contain northern spotted owl nests. Predictive models indicating planning sta...
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... plans also affect marginal parts of the owl's range and include the High Cascades province of Oregon ( Franklin and Dyrness 1973). This province is somewhat isolated from the bulk of the owl's range by the high-elevation subalpine fir/mountain hemlock zone (Figure 1). It is composed of mixed conifer forests favoring western white pine (Pinus monticola), lodgepole pine (Pinus contorta), mountain hemlock (Tsuga mertensiana), subalpine fir (Abies lasiocarpa) and Shasta red fir (Abies magnifica shastenisis) at higher elevations and ponderosa pine (Pinus ponderosa) sugar pine (Pinus lambertiana) and white fir (Abies concolor) at lower elevations (Hopkins 1979). ...
Context 2
... plans also affect mar- ginal parts of the owl's range and include the High Cascades province of Oregon ( Franklin and Dyrness 1973). This province is somewhat isolated from the bulk of the owl's range by the high-elevation subalpine fir/mountain hemlock zone (Figure 1). It is composed of mixed conifer forests favoring western white pine (Pinus monticola), lodgepole pine (Pinus contorta), mountain hemlock (Tsuga mertensiana), subalpine fir (Abies lasiocarpa) and Shasta red fir (Abies magnifi- ca shastenisis) at higher elevations and ponderosa pine (Pinus ponderosa) sugar pine (Pinus lambertiana) and white fir (Abies concolor) at lower elevations (Hopkins 1979). ...
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Citations
... Much of the cited research on the negative impacts of anthropogenic development come from greater sage-grouse whose distribution encompasses significantly more human alteration. It is possible that presence of higher densities of some anthropogenic modifications can increase gene flow precisely because they create unfavorable conditions, prompting individuals to disperse through the area despite the lack of available resources (Ribe et al., 1998;Spear et al., 2010). These relationships highlight the importance of carefully considering the biological mechanism underlying modelled relationships for conservation insight, as TA B L E 2 Rangewide top 10 Gunnison sage-grouse multicovariate model parameter estimates and associated 95% credible intervals (CRI increased anthropogenic footprint will necessarily remove and degrade sagebrush habitat essential for this species to persist (Young et al., 2020). ...
Habitat fragmentation and degradation impacts an organism's ability to navigate the landscape, ultimately resulting in decreased gene flow and increased extinction risk. Understanding how landscape composition impacts gene flow (i.e., connectivity) and interacts with scale is essential to conservation decision‐making. We used a landscape genetics approach implementing a recently developed statistical model based on the generalized Wishart probability distribution to identify the primary landscape features affecting gene flow and estimate the degree to which each component influences connectivity for Gunnison sage‐grouse (Centrocercus minimus). We were interested in two spatial scales: among distinct populations rangewide and among leks (i.e., breeding grounds) within the largest population, Gunnison Basin. Populations and leks are nested within a landscape fragmented by rough terrain and anthropogenic features, although requisite sagebrush habitat is more contiguous within populations. Our best fit models for each scale confirm the importance of sagebrush habitat in connectivity, although the important sagebrush characteristics differ. For Gunnison Basin, taller shrubs and higher quality nesting habitat were the primary drivers of connectivity, while more sagebrush cover and less conifer cover facilitated connectivity rangewide. Our findings support previous assumptions that Gunnison sage‐grouse range contraction is largely the result of habitat loss and degradation. Importantly, we report direct estimates of resistance for landscape components that can be used to create resistance surfaces for prioritization of specific locations for conservation or management (i.e., habitat preservation, restoration, or development) or as we demonstrated, can be combined with simulation techniques to predict impacts to connectivity from potential management actions.
... This lack of relationship is likely the result of a mismatch between dispersal and the habitats modelled in the indices (Ribe et al. 1998;Spear et al. 2010). ...
Functional connectivity, quantified using landscape genetics, can inform conservation through the identification of factors linking genetic structure to landscape mechanisms. We used breeding habitat metrics, landscape attributes and indices of grouse abundance, to compare fit between structural connectivity and genetic differentiation within five long-established Sage Grouse Management Zones (MZ) I-V using microsatellite genotypes from 6,844 Greater Sage-Grouse (Centrocercus urophasianus) collected across their 10.7 million-km² range. We estimated structural connectivity using a circuit theory based approach where we built resistance surfaces using thresholds dividing the landscape into ‘habitat’ and ‘non-habitat’ and Nodes were clusters of sage-grouse leks (where feather samples were collected using non-invasive techniques). As hypothesized, MZ-specific habitat metrics were the best predictors of differentiation. To our surprise, inclusion of grouse abundance-corrected indices did not greatly improve model fit in most MZs. Functional connectivity of breeding habitat was reduced when probability of lek occurrence dropped below 0.25 (MZs I, IV) and 0.5 (II), thresholds lower than those previously identified as required for the formation of breeding leks, which suggests that individuals are willing to travel through undesirable habitat. The individual MZ landscape results suggested terrain roughness and steepness shaped functional connectivity across all MZs. Across respective MZs, sagebrush availability (<10-30%; II, IV, V), tree canopy cover (>10%; I, II, IV) and cultivation (>25%; I, II, IV, V) each reduced movement beyond their respective thresholds. Model validations confirmed variation in predictive ability across MZs with top resistance surfaces better predicting gene flow than geographic distance alone, especially in cases of low and high differentiation among lek-groups. The resultant resistance maps we produced spatially depict the strength and redundancy of range-wide gene flow and can help direct conservation actions to maintain and restore functional connectivity for sage-grouse.
... Multiple studies have demonstrated the positive association between structural connectivity (i.e., habitat) and functional connectivity (i.e., gene flow; Laiolo and Tella 2006;Wang et al. 2008;Row et al. 2010). However, structural habitat connectivity does not always result in functional connectivity (Ribe et al. 1998;Spear et al. 2010). The structural connectivity of seasonal habitats (Fedy et al. 2014;Row et al. 2015) likely influences functional gene flow across the state; however, these habitat may not be as influential as large-scale landscape features that represent substantial areas of unsuitable habitat such as mountain ranges. ...
The identification and demographic assessment of biologically meaningful populations is fundamental to species’ ecology and management. Although genetic tools are used frequently to identify populations, studies often do not incorporate demographic data to understand their respective population trends. We used genetic data to define subpopulations in a continuously distributed species. We assessed demographic independence and variation in population trends across the distribution. Additionally, we identified potential barriers to gene flow among subpopulations. We sampled greater sage-grouse (Centrocercus urophasianus) leks from across their range (≈175,000 Km²) in Wyoming and amplified DNA at 14 microsatellite loci for 1761 samples. Subsequently, we assessed population structure in unrelated individuals (n = 872) by integrating results from multiple Bayesian clustering approaches and used the boundaries to inform our assessment of long-term population trends and lek activity over the period of 1995–2013. We identified four genetic clusters of which two northern ones showed demographic independence from the others. Trends in population size for the northwest subpopulation were statistically different from the other three genetic clusters and the northeast and southwest subpopulations demonstrated a general trend of increasing proportion of inactive leks over time. Population change from 1996 to 2012 suggested population growth in the southern subpopulations and decline, or neutral, change in the northern subpopulations. We suggest that sage-grouse subpopulations in northern Wyoming are at greater risk of extirpation than the southern subpopulations due to smaller census and effective population sizes and higher variability within subpopulations. Our research is an example of incorporating genetic and demographic data and provides guidance on the identification of subpopulations of conservation concern.
... Despite this link, structural connectivity built from habitat suitability indices may not always represent functional connectivity (i.e., gene flow). For example, the habitat used on a daily basis may be different from the habitat a species is willing to travel through when dispersing (Ribe et al. 1998;Spear et al. 2010). Ideally, the comparison of genetic differentiation to resistance derived from habitat suitability indices, as well as individual landscape components, could potentially provide insight into where dispersal and daily-use habitat diverge. ...
Given the significance of animal dispersal to population dynamics and geographic variability, understanding how dispersal is impacted by landscape patterns has major ecological and conservation importance. Speaking to the importance of dispersal, the use of linear mixed models to compare genetic differentiation with pairwise resistance derived from landscape resistance surfaces has presented new opportunities to disentangle the menagerie of factors behind effective dispersal across a given landscape. Here, we combine these approaches with novel resistance surface parameterization to determine how the distribution of high- and low-quality seasonal habitat and individual landscape components shape patterns of gene flow for the greater sage-grouse (Centrocercus urophasianus) across Wyoming. We found that pairwise resistance derived from the distribution of low-quality nesting and winter, but not summer, seasonal habitat had the strongest correlation with genetic differentiation. Although the patterns were not as strong as with habitat distribution, multivariate models with sagebrush cover and landscape ruggedness or forest cover and ruggedness similarly had a much stronger fit with genetic differentiation than an undifferentiated landscape. In most cases, landscape resistance surfaces transformed with 17.33-km-diameter moving windows were preferred, suggesting small-scale differences in habitat were unimportant at this large spatial extent. Despite the emergence of these overall patterns, there were differences in the selection of top models depending on the model selection criteria, suggesting research into the most appropriate criteria for landscape genetics is required. Overall, our results highlight the importance of differences in seasonal habitat preferences to patterns of gene flow and suggest the combination of habitat suitability modeling and linear mixed models with our resistance parameterization is a powerful approach to discerning the effects of landscape on gene flow.
... Ces différentes caractéristiques peuvent toutes être liées plus ou moins directement à la biodiversité présente dans la mosaïque paysagère. Par exemple, la proportion des différents types de patchs ou la taille des patchs peuvent refléter la quantité d'habitats favorables disponibles pour les espèces (Ribe et al. 1998;Lichstein et al. 2002;Barbaro et al. 2007;Hakkarainen et al. 2008). La taille des patchs est également déterminante pour la disponibilité en ressources qui a un impact direct sur la productivité (reproduction, taille des nichées) des espèces et sur la capacité d'un patch d'habitat donné à abriter une population d'espèces (Forman 1995;Oja et al. 2005;Warren et al. 2005). ...
... In forest landscapes, many studies have demonstrated that heterogeneity of stand types and of forest habitats are necessary to maintain high forest-dwelling species diversity (Freemark & Merriam 1986;Noss 1987;Beese & Bryant 1999;Werner & Raffa 2000). For instance, the diversity, area and continuity of forest habitats could reflect amount, diversity and accessibility of resources available for species and are critical for their coexistence (Enoksson et al. 1995;Ribe et al. 1998;Mazerolle & Villard 1999;Lichstein et al. 2002;Macdonald & Fenniak 2007). A wide literature survey was performed in order to carefully choose indices that have been clearly related to intra-forest mosaic characteristics which are critical to maintain forest biodiversity. ...
... These two criteria were based on the same four metrics, which were computed respectively on the forest habitat and stand type raster datasets: area-weighted median patch size (AREA_WMD), patch richness (PR), patch equitability (SIEI) and patch continuity (MESH). All of these metrics reflect complementary intra-forest mosaic characteristics that are considered to be related to forest biodiversity (Harner & Harper 1976;Enoksson et al. 1995;Skov 1997;Bender et al. 1998;Ribe et al. 1998;Werner & Raffa 2000;Chávez & Macdonald 2010). We used Fragstats 3.3 for metrics calculations. ...
There is a general consensus that as pressures on natural resources increase, biodiversity is being lost, and the rate of loss is not sustainable. Within the present situation is become a critical need to develop methods and tools for biodiversity monitoring and conservation. In particular, we need spatially-explicit tools and rapid assessment methods that are relatively easy to implement at different scales and at a relatively low cost. One of the basic assumptions in ecology is that there are positive relationships at different spatial scales between landscape heterogeneity and species richness in a given landscape mosaic. In this thesis, we focus on this assumption in order to build a Potential Species Biodiversity Index. Our aim was to assess potential biodiversity within a forest landscape mosaic, considering the Vercors' mountain range as a case study. The index encompasses indirect biodiversity indicators and criteria as a surrogate to biodiversity potential present for a given area. This approach allows a better understanding of the relationships between forests stand structure, forest landscape characteristics and species richness or geographical distribution. The main steps of the method and its evaluation are presented in scientific papers. The analysis of geographical distribution of the index at different spatial scales provides practical applications for conservation planning and multifunctional forest management related fields.
... Ces différentes caractéristiques peuvent toutes être liées plus ou moins directement à la biodiversité présente dans la mosaïque paysagère. Par exemple, la proportion des différents types de patchs ou la taille des patchs peuvent refléter la quantité d'habitats favorables disponibles pour les espèces (Ribe et al. 1998;Lichstein et al. 2002;Barbaro et al. 2007;Hakkarainen et al. 2008). La taille des patchs est également déterminante pour la disponibilité en ressources qui a un impact direct sur la productivité (reproduction, taille des nichées) des espèces et sur la capacité d'un patch d'habitat donné à abriter une population d'espèces (Forman 1995;Oja et al. 2005;Warren et al. 2005). ...
... In forest landscapes, many studies have demonstrated that heterogeneity of stand types and of forest habitats are necessary to maintain high forest-dwelling species diversity (Freemark & Merriam 1986;Noss 1987;Beese & Bryant 1999;Werner & Raffa 2000). For instance, the diversity, area and continuity of forest habitats could reflect amount, diversity and accessibility of resources available for species and are critical for their coexistence (Enoksson et al. 1995;Ribe et al. 1998;Mazerolle & Villard 1999;Lichstein et al. 2002;Macdonald & Fenniak 2007). A wide literature survey was performed in order to carefully choose indices that have been clearly related to intra-forest mosaic characteristics which are critical to maintain forest biodiversity. ...
... These two criteria were based on the same four metrics, which were computed respectively on the forest habitat and stand type raster datasets: area-weighted median patch size (AREA_WMD), patch richness (PR), patch equitability (SIEI) and patch continuity (MESH). All of these metrics reflect complementary intra-forest mosaic characteristics that are considered to be related to forest biodiversity (Harner & Harper 1976;Enoksson et al. 1995;Skov 1997;Bender et al. 1998;Ribe et al. 1998;Werner & Raffa 2000;Chávez & Macdonald 2010). We used Fragstats 3.3 for metrics calculations. ...
Le déclin de la biodiversité lié à l’augmentation des pressions sur les ressources naturelles, fait l’objet d’un large consensus. Cette situation souligne un besoin urgent de développer des outils de diagnostic et de suivi de l’état de la biodiversité qui soient spatialisés, rapides à mettre en ½uvre, peu coûteux et qui permettent de réaliser des expertises à l’échelle des territoires. Une des hypothèses centrales en écologie est qu’il existe des relations positives entre l’hétérogénéité spatiale mesurée dans la mosaïque paysagère et la richesse en espèces qui peut y cohabiter à différentes échelles. Dans ce travail, nous nous appuyons sur cette hypothèse pour développer un Indice de Biodiversité Spécifique Potentielle afin de réaliser un diagnostic de l’état de la biodiversité dans la mosaïque paysagère intra-forestière à différentes échelles, en prenant l’exemple du massif du Vercors. Cet indice s’appuie sur des indicateurs et des critères capables de refléter le niveau de biodiversité potentiellement présente dans une zone géographique donnée, et permet d’approfondir les connaissances sur les relations entre la structure des peuplements, les caractéristiques de la mosaïque forestière et la richesse ou la répartition géographique des espèces. Les étapes clés de la méthodologie et de son évaluation sont valorisées sous forme d’articles. La représentation spatiale de la biodiversité potentielle à différentes échelles permet d’envisager de nombreuses applications dans les domaines de la conservation et de la gestion forestière multifonctionnelle.
... Rigorous methods for carrying out resource selection functions were documented in the wildlife literature in 1993 (Manly et al. 1993). Landscape ecology, a relatively young discipline compared with wildlife biology, began with spatially explicit models that placed emphasis on pattern description (e.g., Ribe et al. 1998) and issues of scale (e.g., Naugle et al. 1999). Here, the relationship between landscape pattern and process (one of the fundamental tenets of the sub-discipline) underpins much of the modeling work. ...
The field of predictive habitat modeling evolved somewhat separately within the sub-disciplines of theoretical ecology, wildlife
management, and landscape ecology. This chapter suggests that this is due to slightly different worldviews, cultures, and
research applications within each subfield (Table 11.1). Within the theoretical ecology literature, models of all kinds (e.g.,
movement, foraging, competition, demographic) have been widespread for many years. The evolution from descriptive models of
habitat quality (e.g., Whittaker and McCuen 1976), to mathematical formulations of niche (e.g., Austin 1985), to spatially-explicit
predictive habitat models (e.g., Saarenmaa et al. 1988) was a gradual one. The driving force in this literature appears to
be underlying theoretical formulations of a host of ecological processes and interactions (e.g., population dynamics, movement,
predation, competition).
... In the northerly portion of its range, in areas where the northern flying squirrel (Glaucomys sabrinus; an older forest associate) is the primary prey, understory development is important in both older and younger forest (Carey et al., 1992), and the NSO may be negatively associated with the amount of edge. The NSO selected nest locations with large patches of older forests and low amounts of forest edge in the high Cascades of southern Oregon; landscapes with extensive edges between openings and forest not suitable for nesting were less likely to be selected (Ribe et al., 1998). Thus, spatial pattern is important to the NSO. ...
Regional conservation planning frequently relies on general assumptions about historical disturbance regimes to inform decisions about landscape restoration, reserve allocations, and landscape management. Spatially explicit simulations of landscape dynamics provide quantitative estimates of landscape structure and allow for the testing of alternative scenarios. We used a landscape fire succession model to estimate the historical range of variability of vegetation and fire in a dry forest landscape (size ca. 7900 km2) where the present-day risk of high severity fire threatens the persistence of older closed canopy forest which may serve as Northern Spotted Owl (Strix occidentalis caurina) habitat. Our results indicated that historically, older forest may have comprised the largest percentage of the landscape (∼35%), followed by early successional forest (∼25%), with about 9% of the landscape in a closed canopy older forest condition. The amount and condition of older forest varied by potential vegetation type and land use allocation type. Vegetation successional stages had fine-grained spatial heterogeneity in patch characteristics, with older forest tending to have the largest patch sizes among the successional stages. Increasing fire severities posed a greater risk to Northern Spotted Owl habitat than increasing fire sizes or frequencies under historical fire regimes. Improved understanding of historical landscape-specific fire and vegetation conditions and their variability can assist forest managers to promote landscape resilience and increases of older forest, in dry forests with restricted amounts of habitat for sensitive species.
... The relationship between landscape metrics and bird species richness and their habitat preferences has been studied most extensively. There are many studies that have been performed on the relationships between landscape parameters and specific species -owls (Carey et al., 1992;Ribe et al., 1998), sparrows (Perkins and Conner, 2003), turkeys (Chamberlain et al., 2000;Miller and Conner, 2007), woodpeckers (Wigley et al., 1999), bobwhites (Guthery et al., 2001;Twedt et al., 2007), grouses (Fearer and Stauffer, 2003), pheasants (Clark et al., 1999) and ducks (Stephens et al., 2005). Different studies have shown that most bird species responded more strongly to the composition of land-cover classes than to the configuration of the landscape (Table 1). ...
The aim of this overview paper is to analyze the use of various landscape metrics and landscape indices for the characterization of landscape structure and various processes at both landscape and ecosystem level. We analyzed the appearance of the terms landscape metrics/indexes/indices in combination with seven main categories in the field of landscape ecology [1) use/selection and misuse of metrics, 2) biodiversity and habitat analysis; 3) water quality; 4) evaluation of the landscape pattern and its change; 5) urban landscape pattern, road network; 6) aesthetics of landscape; 7) management, planning and monitoring] in the titles, abstracts and/or key words of research papers published in international peer-reviewed scientific journals indexed by the Institute of Science Information (ISI) Web of Science (WoS) from 1994 to October 2008. Most of the landscape metrics and indices are used concerning biodiversity and habitat analysis, and also the evaluation of landscape pattern and its change (up to 25 articles per year). There are only a few articles on the relationships of landscape metrics/indices/indexes to social aspects and landscape perception.
... The factors involved in determining suitable breeding habitat have been investigated for a number of different species (e.g. Bian and West, 1997;Ribe et al., 1998;Howell et al., 2000;Lawler and Edwards, 2002). For the grey seal, a small number of Scottish breeding colonies have been intensively studied, and this has resulted in numerous qualitative descriptions of the environmental factors that females may use when selecting a pupping site at these colonies (Boyd et al., 1962;Prime, 1981;Anderson and Harwood, 1985;Pomeroy et al., 1994Pomeroy et al., , 2000aCaudron, 1995). ...
Understanding the habitat requirements of a species for breeding is essential for its conservation, particularly if the availability of suitable habitat is a limiting factor for population growth. This is postulated to be the case for grey seals, one of the more abundant marine apex predators in northern European waters. In common with similar studies that have investigated the habitat preferences of breeding grey seals, we use abiotic (topographical, climatological) attributes but, unlike previous work, we also incorporate behavioural variables, particularly the occurrence of aggressive interactions between females and the presence of neighbouring seals. We used two Generalized Additive Models (GAM) in a sequential and iterative fashion. The first model links the occurrence of aggression at particular points in the colony to local topography derived from a Geographical Information System (GIS), presence of neighbouring seal pups and the day of the breeding season. The output of this GAM is used as one of the explanatory variables in a GAM of daily variation in the spatial distribution of births. Although proximity of a birth site to a water source and the presence of neighbouring seal pups both had significant influences on the distribution of newborn pups over time and space, at the scale of the study site it was found that simple rules could predict pup distribution more efficiently than a complex individual-based simulation model.
