Article

Quantitatively Evaluating Restoration Experiments: Research Design, Statistical Analysis, and Data Management Considerations

Authors:
To read the full-text of this research, you can request a copy directly from the author.

Abstract

Conceptual and logistical challenges associated with the design and analysis of ecological restoration experiments are often viewed as being insurmountable, thereby limiting the potential value of restoration experiments as tests of ecological theory. Such research constraints are, however, not unique within the environmental sciences. Numerous natural and anthropogenic disturbances represent unplanned, uncontrollable events that cannot be replicated or studied using traditional experimental approaches and statistical analyses. A broad mix of appropriate research approaches (e.g., long-term studies, large-scale comparative studies, space-for-time substitution, modeling, and focused experimentation) and analytical tools (e.g., observational, spatial, and temporal statistics) are available and required to advance restoration ecology as a scientific discipline. In this article, research design and analytical options are described and assessed in relation to their applicability to restoration ecology. Significant research benefits may be derived from explicitly defining conceptual models and presuppositions, developing multiple working hypotheses, and developing and archiving high-quality data and metadata. Flexibility in research approaches and statistical analyses, high-quality databases, and new sampling approaches that support research at broader spatial and temporal scales are critical for enhancing ecological understanding and supporting further development of restoration ecology as a scientific discipline.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the author.

... Replication may also be difficult. These difference mean that the experiment design may also differ from non-restoration studies (Michener et al. 1997). ...
... The experimental design of a study and its use of statistical analysis influence each other greatly, guided by the questions asked by the study (Michener et al. 1997, Lortie 2014. Since restoration studies can differ in design from more traditional study ecologies, the statistical test chosen to examine the data may differ as well (Michener et al. 1997). ...
... The experimental design of a study and its use of statistical analysis influence each other greatly, guided by the questions asked by the study (Michener et al. 1997, Lortie 2014. Since restoration studies can differ in design from more traditional study ecologies, the statistical test chosen to examine the data may differ as well (Michener et al. 1997). This can lead to less common statistics being used in these types of studies or to the use of more common statistical tests in different ways (Michener et al. 1997). ...
Preprint
Full-text available
Restoration ecology is the study of restoration or restoration practices in degraded areas. It is of particular importance in arid environments due to the heavy impact humans have had in these areas. Some studies of restoration may require different statistics due to the unique challenges faced when examining degraded areas. A systematic review was conducted to assess the use of statistics in the field. It was determined that the field and influence of restoration ecology had increased dramatically since its development. Statistics are widely used in the study of restoration of arid areas. Major tests are similar to those found in other ecological studies such as ANOVAs and linear regressions. There were a few less common tests used in some of the studies. These include tests such as the Mantel test which may be useful to restoration ecology and should be explored further. Finally it was determined that the description of how statistics were used in the study was particularly important. The description should be detailed to help other researchers understand the findings of the paper. This will help to advance the field and the restoration of arid environments.
... Manipulative experiments can yield great inferential power, particularly in complex landscapes, providing added confidence that the observed effect was due to mitigation and not to other factors (Evans, Riley, & Lamberti, 2015;Rytwinski et al., 2015; van der Grift et al., 2013). However, implementing an experimental approach is challenging and examples in road ecology are rare (Michener, 1997;Rytwinski et al., 2015). The second component missing from most evaluations is the use of genetic techniques (Balkenhol & Waits, 2009;Simmons, Sunnucks, Taylor, & van der Ree, 2010;Sunnucks & Balkenhol, 2015). ...
... Large-scale ecological experiments are often called for in ecology and conservation, but are notoriously difficult to implement and often heavily constrained in the real world (Michener, 1997;Roedenbeck et al., 2007;van der Ree, Jaeger, Rytwinski, & van der Grift, 2015). Our study was no exception. ...
Article
Millions of dollars are spent on wildlife crossing structures intended to reduce the barrier effects of roads on wildlife. However, we know little about the degree to which these structures facilitate dispersal and gene flow. Our study incorporates two elements that are rarely used in the evaluation of wildlife crossing structures: an experimental design including a before and after comparison, and the use of genetic techniques to demonstrate effects on gene flow at both population and individual levels. We evaluated the effect of wildlife crossing structures (canopy bridges and glider poles) on a gliding mammal, the squirrel glider (Petaurus norfolcensis). We genotyped 399 individuals at eight microsatellite markers to analyse population structure, first-generation migrants and parentage relationships. We found that the freeway was not a complete genetic barrier, with a strong effect evident at only one site. We hypothesise that the presence of corridors alongside the freeway and throughout the surrounding landscape facilitated circuitous detours for squirrel gliders. Installing a crossing structure at the location with a strong barrier effect restored gene flow within just five years of mitigation. Synthesis and applications. Our study highlights the importance of using genetic techniques not just to evaluate the success of road crossing structures for wildlife, but also to guide their placement within the landscape. Managers wishing to reduce the effects of linear infrastructure on squirrel gliders and other arboreal mammals should aim to preserve and enhance vegetation along roadsides and within centre medians, as well as mitigate large gaps by implementing wildlife crossing structures.
... Restoration ecologists have a number of decisions regarding planning an effective experimental design, and the appropriate statistics for both the design and the type of data that is collected. A study by Michener (1997) described the kinds of statistical tests that could be used depending on the type of restoration experiment. These include ANOVAs and regressions for comparing the results of experimental designs such as testing the effect of a treatment, and ordinations for analyzing changes in community structure or species distributions, and finally time series analyses for examining pre and post restoration sampling. ...
... These include ANOVAs and regressions for comparing the results of experimental designs such as testing the effect of a treatment, and ordinations for analyzing changes in community structure or species distributions, and finally time series analyses for examining pre and post restoration sampling. Since Michener's 1997 paper, there has not been a review of the types of statistical analyses used. A review of this kind is important to identify what statistics are being done and how in order for to identify potential weaknesses and give recommendations for future directions important to the advancement of this field. ...
Preprint
Full-text available
Restoration ecology is a rapidly growing field of research. The statistical analyses and experimental designs used in this field have likely also expanded. In this review, the statistical scope of the restoration ecology of invaded grasslands will be investigated. A systematic review was conducted on 103 articles to examine the types of statistical tests used and how they changed over time, if assumptions are tested, and how the number of statistical tests and the experimental design influence both the citation rate of articles and the impact factor of journals where these articles are published. ANOVAs have consistently been the dominant test. Statistical test diversity has increased since the year 2000. Most articles did test the assumptions of statistical analyses. The number of tests, and sample size of experiments are both positively correlated with the average citation rate of articles and the impact factor of the journal while the number of factors was negatively correlated. GLMs are recommended as a statistical test to be used more frequently in the future over ANOVAs. There is room for improvement in terms of reporting statistics accurately, including testing assumptions. When possible, sample sizes should be increased to both increase the quality of data, and the citation rate and the journal impact where articles are published. When possible and appropriate, sample sizes and the number of statistical tests should be increased. Adding factors in experimental designs should only be done so without compromising sample size as it has been shown to hinder the citation rate and journal impact.
... In the light of this suggested approach, restoration efforts could be planned as "experimental" sites, an approach that will naturally facilitate an objective evaluation of outcomes as part of a research effort. Michener (1997) has stressed that, without proper ecological audit of existing restoration sites, future restoration projects will not benefit from past attempts, a notion that has been termed in other disciplines as "double-loop learning." Michener (1997) had previously identified the need for empirical evidence to address the following generic questions: (i) Have restoration activities succeeded or failed? ...
... Michener (1997) has stressed that, without proper ecological audit of existing restoration sites, future restoration projects will not benefit from past attempts, a notion that has been termed in other disciplines as "double-loop learning." Michener (1997) had previously identified the need for empirical evidence to address the following generic questions: (i) Have restoration activities succeeded or failed? (ii) How and what was the science behind the success or failure? ...
... 20 An efficient and direct way to evaluate restoration is to use a before-after/control-impact (BACI) design to compare changes in systems at treated sites to those within controls using data gathered before and after application. 21,22 Beforeafter/control-impact designs provide a robust way to identify changes associated with treatments because they consider 2 or more time periods and explicit controls, which reduces the potential for confounding due to environmental variation or natural changes in resources over time. 23 Unfortunately, logistical and administrative issues often linked to funding can make rigorous evaluations of restoration impacts difficult and limit our understanding of the benefits and ways to improve future efforts. ...
... 23 Unfortunately, logistical and administrative issues often linked to funding can make rigorous evaluations of restoration impacts difficult and limit our understanding of the benefits and ways to improve future efforts. 21 Here, we addressed some of these challenges through explicit use of a BACI design, data on multiple ecological indicators, and spatial replication across numerous treatment and control areas at 3 sites and 10 ranches. ...
Article
Full-text available
Restoring and enhancing riparian vegetation on private and communal lands in Mexico is important for biodiversity conservation given the ecological significance of these areas and the scarcity of public protected areas. To enhance riparian vegetation and wildlife habitats and train local people in restoration techniques, we implemented restoration and outreach efforts on private and communal lands in the Sky Islands region of northwest Mexico. We fenced 475 ha of riparian zones from livestock, erected erosion-control structures, planted trees, and developed management agreements for cool-season grazing with landowners on 10 ranches across 3 sites in 2012-2013, then repaired fences and renegotiated agreements in 2017-2019. To foster evaluation, we used a before-after/control-impact design to measure attributes of vegetation structure and bird communities and compared baselines from 2012 with post-treatment estimates from 2019. As predicted, understory vegetation volume generally increased in treatments relative to controls (P = .09), especially when one treatment area with the lowest pre-treatment grazing impacts was censored (P = .01). Although canopy cover also increased, there was little differential change in treatments relative to con-trols (P ⩾ .23) due likely to longer time periods needed to realize responses. Densities of most focal bird populations varied across time periods in directions that typically matched observed changes in vegetation structure, but fewer species showed signs of differential positive change linked to treatments relative to controls. Densities of Yellow-breasted Chat, a key understory obligate and important focal species, increased in treatments relative to controls across sites, as did densities of Sinaloa Wren, which also use dense underbrush (P⩽ .05). Positive changes by other understory obligates (eg, Common Yellowthroat, Song Sparrow) were more local but sometimes of high magnitude (>8-fold) also suggesting positive impacts of treatments. Despite mixed results over a limited time period, these patterns suggest restoration efforts drove localized recovery of understory vegetation and associated bird populations, but benefits varied widely with environmental and social factors linked to management. Greater ecological benefits to riparian areas on private and communal lands in this region can be fostered by further incentivizing construction, maintenance, and proper use of restoration infrastructure, through education, and by building relationships based on trust and credibility with landowners
... Since there were no reforested areas of similar restoration ages in the same landscape to act as ideal replicates, we considered sampling plots within each site as replicates of restoration age and width in our experimental design. Although we are aware of the issues associated with pseudo replication, this sampling design has been successfully used in studies of restoration ecology performed on a site-specific basis, where no replication across the landscape is feasible (Michener 1997;Hurlbert 1984;Gilliam 2002;Martins and Antonini 2016). Replication is impractical for many restoration treatments, given that replicate sites might simply not be present in a given area. ...
... Replication is impractical for many restoration treatments, given that replicate sites might simply not be present in a given area. Despite the known limitations of this design, the results obtained can be used for understanding the recovery of arthropod communities in restored areas by providing crucial insights into long-term trends (Michener 1997;Sant'Anna et al. 2014). ...
Article
Full-text available
Riparian forests have been greatly affected by anthropogenic actions with formerly continuous riparian forests being slowly converted into small and isolated patches. Riparian forests are extremely important habitats for many groups of insects, including bees and wasps, because they are sources of shelter and food for them and their offspring. There is a growing body of evidence of success in the restoration of riparian forest plant communities; however, little research has been done on the associated invertebrate communities. We test whether restoring plant communities is sufficient for restoring the taxonomic composition of trap-nesting bees and wasps and which functional traits are favored in different sites. We predict that species richness, abundance, and community composition of trap-nesting bees and wasps of riparian sites undergoing restoration will converge on the “target” of a reference site with increasing time, since restoration increases habitat complexity. We also predict that the width of restored patches will also influence the species richness, abundance and community composition of trap-nesting bees and wasps. Bee richness and abundance, and wasp richness, were strongly related to fragment width, but not to age since restoration. Our results indicate that although restored sites are relatively small and scattered in a fragmented landscape, they provide suitable habitat for re-colonization by community assemblages of trap-nesting bees and wasps and the traits selected captured the responses to the habitat restoration. Hence, restored riparian areas can be considered important habitats for invertebrates, thus contributing to an increase in local biodiversity and, possibly, the restoration of some of the ecosystem services they originally provided.
... Les options d'intervention choisies pour la première phase de la réhabilitation diffèrent de celles de la seconde phase de gestion, en ter mes d'outils et d'objectifs . L'évaluation des résultats doit être basée sur des indica teurs appropriés mesurés sur une période suffisante en intégrant les multiples cau ses de variation temporelle (Kentula et al. , 1993 ;White & Walker, 1997 ;Michener, 1997). ...
... To our knowledge, the effect of grain size on detection of the effect of restoration on forest community composition has received scant attention (but see: Korb et al. 2003 and. Especially in restoration monitoring, sampling at different scales is strongly recommended (Block et al. 2001;Chapman 1999;Underwood and Chapman 2003;Metlen and Fiedler 2006;Marignani et al. 2007Marignani et al. , 2008 to describe scale-dependent variation for ecosystems and landscapes (Michener 1997;White and Walker 1997). ...
Article
Monitoring restoration effectiveness implies that restoration measures should be evaluated using multiscale analysis and modelling approaches. In this way, the scale-dependent nature of ecosystem processes and dynamics can be adequately described. Here, we evaluated how grain size (i.e. the dimension of sampling units) and type of data (abundance vs. presence/absence) impact the analysis of the response to restoration management activities aiming at halting the loss of European beech forests with Abies alba in the central Apennines (Italy). The proposed analysis relies on forests sampled in three Sites of Community Importance (SCIs) located in central Italy. For each treatment (reference, control and impact), randomly located multi-scale plots were selected. Vascular plant occurrences were recorded twice in every plot during summer 2010 or 2011 (before restoration) and in 2013 or 2014 (after restoration). Analysis of species abundances, recorded at the largest grain size available (20 X 20 m plot), showed a significant change in plant species composition in restored sites just after two years from the restoration management. When presence/absence data were used previous results were less visible, for all the examined grains, in two out of the three sites, suggesting a site-dependent response.
... Agency research programs should be developed to investigate ecological tradeoffs of alternative approaches and study the effectiveness of restoration treatments. Where possible, projects should be designed as experiments with replicates and controls to test alternative hypotheses (Sexton & Czaro 1999, Michener 1997. New understanding resulting from these efforts should then be used adjust subsequent restoration activities, enabling an adaptive management approach (Walters & Holling 1990). ...
... Monitoring and evaluating ecological restoration projects is crucial to evaluating treatment efficacy and improving future management actions (Michener 1997). One way to assess the potential effects of restoration on a wildlife species is to track short-term changes in habitat, assuming that these will lead to long-term population changes. ...
Article
Full-text available
Conifer woodlands have expanded into sagebrush (Artemisia spp.) ecosystems and degrade habitat for sagebrush obligate species such as the Greater Sage-grouse (Centrocercus urophasianus). Conifer management is increasing despite a lack of empirical evidence assessing outcomes to grouse and their habitat. Although assessments of vegetation recovery after conifer removal are common, comparisons of successional trends with habitat guidelines or actual data on habitat used by sage-grouse is lacking. We assessed impacts of conifer encroachment on vegetation characteristics known to be important for sage-grouse nesting. Using a controlled repeated measures design, we then evaluated vegetation changes for 3 years after conifer removal. We compared these results to data from 356 local sage-grouse nests, rangewide nesting habitat estimates, and published habitat guidelines. We measured negative effects of conifer cover on many characteristics important for sage-grouse nesting habitat including percent cover of forbs, grasses, and shrubs, and species richness of forbs and shrubs. In untreated habitat, herbaceous vegetation cover was slightly below the cover at local nest sites, while shrub cover and sagebrush cover were well below cover at the nest sites. Following conifer removal, we measured increases in herbaceous vegetation, primarily grasses, and sagebrush height. Our results indicate that conifer abundance can decrease habitat suitability for nesting sage-grouse. Additionally, conifer removal can improve habitat suitability for nesting sage-grouse within 3 years, and trajectories indicate that the habitat may continue to improve in the near future. Implications for Practice • Increased conifer cover in sagebrush ecosystems reduces shrub understory vegetation characteristics important for sage-grouse nesting, thereby limiting habitat suitability and availability for sage-grouse. • Conifer removal increases herbaceous vegetation in a short time period which increases habitat suitability for sage-grouse nesting habitat. Shrubs may not respond as quickly. • Different conifer removal methods may have differing impacts on understory vegetation. Managers should consider and attempt to limit potential negative affects, such as decreased shrub cover or increased exotic annual grasses, when planning conifer removal projects. • Managers should first focus conifer removal efforts in areas with intact shrub and herbaceous composition to achieve the quickest and most complete habitat recovery.
... After removing some less relevant questions, all constructs passed the tests: see Table 2. Most variables were then averaged and transformed (some reversed) onto a scale between 0 and 1, where 0 represents no usage or negative attitude whereas 1 represents very high usage or positive attitude. T-tests were done when a variable was nominal, to test if the difference of means was statistically significant [31]. For correlations between ordinal variables the non-parametric Spearman rank order correlation test was applied (all with the StatSoft Statistica software). ...
Conference Paper
There is a global demand for graduates with computing skills as well as a global shortage of computing professionals, especially women. In Africa these shortages are even more critical. To resolve this problem, studies in the past have argued for increased computing usage in schools that would lead to increased interest in computing degrees. Recently computing usage in the form of mobile devices and mobile gaming has increased substantially in schools, yet in South Africa interest in studying computing at a tertiary level has not increased substantially. Hence, this paper aims to determine whether mobile and gaming usage impacts school learners’ attitude towards computer related degrees. A survey of 292 South African secondary school learners confirms low interest in computing degrees, especially by girls, as well as misperceptions of computing degrees. An IT Usage Attitude Model is proposed and validated in which mobile and gaming usage vary substantially based on gender but usage does not influence attitude towards computing degrees.
... Such approach has been used in similar studies in restoration ecology where optimal sampling design (i.e. presence of experimental controls and age replicates within one site) may not be available (cf. Michener 1997). ...
Article
Full-text available
We investigated: (1) the changes in the nekton community with increasing mangrove forest age (composed of 6-, 8-, 10-, 11-and 18-yr old stands); (2) the relationship among the nekton community and the mangrove vegetation, mangrove soils, and environmental variables; and (3) the nekton community as a potential indicator for evaluating progress of mangrove restoration programs. Nekton were collected using a triangular trap net (mesh size = 2 mm) with 10 m wingspan on each side (area = 43.3 m2) that was set ~ 1 m from the edge of mangrove sites facing the shoreline, for three consecutive nights (before, during and after the spring tide). The trap net was designed to catch nekton that enter mangroves at high tide and were potentially trapped as tide recedes. A total of 99 species from 52 families comprised of crabs, shrimp, squid and fi shes was recorded. Among the dominant families were Portunidae and Penaeidae (for crustaceans) and Atherinidae, Apogonidae, Hemirhamphidae, Tetraodontidae, Congridae, Sphyraenidae, Murraenidae, Ambassidae, Gerreidae, Clupeidae, Platycephalidae, Gobiidae, Mullidae and Plotosidae (for fi shes) accounting for 90% of all collected individuals. Except for the 18-yr stands, the nekton abundance and biomass from each stand did not signifi cantly varied with sampling periods. However, the nekton communities 159 PROCEEDINGS PROCEEDINGS varied signifi cantly with mangrove developmental stages. The young (< 10 yrs), intermediate (10-12 yrs), and mature (> 12 yrs) stands clustered together and were signifi cantly diff erent with the natural stands. The species composition, abundance and biomass of the nekton community were not signifi cantly correlated with mangrove stand age, vegetation and soil, but were rather signifi cantly associated with environmental variables, particularly proximity to reef and elevation. The lack of correlation suggests that nekton, as a whole, is not a useful indicator in evaluating the progress of restoring habitat functionality in planted mangroves. However, removing the fi sh assemblage and a reanalysis of other species yielded signifi cant eff ects of mangroves on nekton community. Crustaceans, particularly of the families Portunidae and Penaeidae, were useful indicators for determining the habitat functionality of planted mangroves. Species under these families (particularly crabs and shrimps) are mangrove-dependent species that have stronger affi nity to mangroves than the mangrove-transient species such as fi shes.
... Series"), frecuentemente utilizado en la evaluación de proyectos de restauración (Michener et al., 1997;Underwood, 1994). El diseño implica la comparación de un tramo o área potencialmente impactada (en este caso, el tramo donde se realizó la intervención) con tramos control, mediante mediciones temporales durante un período anterior y uno posterior al comienzo de la intervención, lo que permite incorporar al análisis la variabilidad temporal y espacial de todos los tramos. ...
Thesis
Full-text available
Los arroyos que atraviesan áreas urbanas son cuerpos de agua altamente vulnerables debido a las transformaciones que el ser humano imprime sobre ellos para adecuarlos a un determinado uso cotidiano. Esto provoca un desequilibrio en la dinámica del sistema ecológico al alterar su morfología, la estructura y diversidad de las comunidades biológicas que lo habitan y las funciones ecológicas que desempeñan. Al mismo tiempo, la transformación de los sistemas lóticos trae aparejada una pérdida en distintos aspectos ecológicos percibidos por el ser humano como beneficios (bienes y servicios ecosistémicos) para mejorar su calidad de vida. La creciente preocupación por mejorar el estado de ríos y arroyos urbanos ha propiciado el desarrollo de numerosos proyectos de rehabilitación. En este trabajo hemos abordado la rehabilitación de un tramo del arroyo San Francisco (Claypole, provincia de Buenos Aires) mediante el manejo de la vegetación riparia y la re-inserción de macrófitas nativas, aplicando un enfoque socio-ecológico y de Investigación-Acción Participativa (IAP). Trabajamos junto con una cuadrilla del barrio, abocada a la limpieza y mantenimiento del arroyo, bajo el precepto de que un abordaje participativo y comunitario que incluya a todos los actores involucrados en la toma de decisiones es un elemento fundamental para garantizar el éxito en la implementación de un plan de rehabilitación a largo plazo. Utilizando un diseño BACIPS asimétrico (Before-After Control-Impact Paired Series) se evaluó el efecto de la intervención sobre la cobertura y riqueza de macrófitas, sobre la concentración y retención neta a nivel de tramo de los principales nutrientes disueltos, y sobre la estructura y función de las comunidades algales perifíticas mediante el estudio de variables de masa y la identificación de los grupos funcionales principales. El abordaje socio-ecológico de la problemática ambiental permitió identificar los problemas que afectaban la calidad del arroyo, así como las valoraciones personales que conllevaba la rehabilitación de ese curso de agua para los integrantes de la cuadrilla, poniendo de manifiesto la importancia sanitaria y eco-comunitaria por sobre el valor netamente estético. La supervivencia de las macrófitas trasplantadas alcanzó un 30% del número de parches trasplantados tres meses después de la intervención, con un aumento sostenido de la riqueza en el tramo intervenido. Sin embargo, no se observó un efecto neto sobre la retención de los principales nutrientes en el arroyo ni en la turbidez del cuerpo de agua. El empleo del perifiton como indicador de cambios en el arroyo permitió detectar un potencial efecto de la intervención. Se registraron variaciones en la comunidad algal perifítica, con un aumento significativo en su biomasa y un recambio en los grupos funcionales. Este proyecto representa una experiencia de integración de saberes y de vinculación de la investigación científica con los problemas de la sociedad desde un enfoque participativo y transversal, con el compromiso de aportar al fortalecimiento de las organizaciones populares para una mejora en el hábitat urbano y las condiciones de vida de la población.
... A more weather-centric approach would require interpretation of individual-year results through the lens of weather conditions during an individual field trial ( Fig. 3; Monaco et al., 2016). Development of predictive models for rangeland-revegetation success from these data may require additional meta-analyses across multiple field conditions in which relative weather for a given site and year are covariables (Michener, 1997;Johnson, 2006). ...
Article
Invasive annual weeds negatively impact ecosystem services and pose a major conservation threat on semiarid rangelands throughout the western United States. Rehabilitation of these rangelands is challenging due to interannual climate and subseasonal weather variability that impacts seed germination, seedling survival and establishment, annual weed dynamics, wildfire frequency, and soil stability. Rehabilitation and restoration outcomes could be improved by adopting a weather-centric approach that uses the full spectrum of available site-specific weather information from historical observations, seasonal climate forecasts, and climate-change projections. Climate data can be used retrospectively to interpret success or failure of past seedings by describing seasonal and longer-term patterns of environmental variability subsequent to planting. A more detailed evaluation of weather impacts on site conditions may yield more flexible adaptive-management strategies for rangeland restoration and rehabilitation, as well as provide estimates of transition probabilities between desirable and undesirable vegetation states. Skillful seasonal climate forecasts could greatly improve the cost efficiency of management treatments by limiting revegetation activities to time periods where forecasts suggest higher probabilities of successful seedling establishment. Climate-change projections are key to the application of current environmental models for development of mitigation and adaptation strategies and for management practices that require a multidecadal planning horizon. Adoption of new weather technology will require collaboration between land managers and revegetation specialists and modifications to the way we currently plan and conduct rangeland rehabilitation and restoration in the Intermountain West.
... Monitoring and evaluating ecological restoration projects is crucial to evaluating treatment efficacy and improving future management actions (Michener 1997). One way to assess the potential effects of restoration on a wildlife species is to track short-term changes in habitat, assuming that these will lead to long-term population changes. ...
Article
Conifer woodlands have expanded into sagebrush (Artemisia spp.) ecosystems and degrade habitat for sagebrush obligate species such as the Greater Sage-grouse (Centrocercus urophasianus). Conifer management is increasing despite a lack of empirical evidence assessing outcomes to grouse and their habitat. Although assessments of vegetation recovery after conifer removal are common, comparisons of successional trends with habitat guidelines or actual data on habitat used by sage-grouse is lacking. We assessed impacts of conifer encroachment on vegetation characteristics known to be important for sage-grouse nesting. Using a controlled repeated measures design, we then evaluated vegetation changes for 3 years after conifer removal.We compared these results to data from 356 local sage-grouse nests, rangewide nesting habitat estimates, and published habitat guidelines. We measured negative effects of conifer cover on many characteristics important for sage-grouse nesting habitat including percent cover of forbs, grasses, and shrubs, and species richness of forbs and shrubs. In untreated habitat, herbaceous vegetation cover was slightly below the cover at local nest sites, while shrub cover and sagebrush cover were well below cover at the nest sites. Following conifer removal, we measured increases in herbaceous vegetation, primarily grasses, and sagebrush height. Our results indicate that conifer abundance can decrease habitat suitability for nesting sage-grouse. Additionally,conifer removal can improve habitat suitability for nesting sage-grouse within 3 years, and trajectories indicate that the habitat may continue to improve in the near future.
... Durante el proceso de recuperación de un ecosistema, el resultado final puede no llegar a una completa restauración funcional y estructural como se desearía. Durante la trayectoria de recuperación puede ocurrir que los procesos ecosistémicos no sigan un desarrollo ordenado hasta un único punto final, ya que por un lado los ecosistemas son dinámicos aunque sigan tendencias sucesionales y también pueden pasar por rápidas transiciones entre diferentes estados estables hacia múltiples puntos terminales (Choi, 2004;Choi, 2007;Ehrenfeld & Toth, 1997;Harris et al., 2006;Hobbs & Norton, 1996;McLane & Aitken, 2012;Michener, 1997;Palmer, Ambrose & Poff, 1997;White & Walker, 1997). De esto se derivaron otros conceptos relacionados con la recuperación de ecosistemas, tales como rehabilitación y reclamación o reemplazo (Figura 1). ...
Article
Full-text available
Ecological restoration is a very active area in ecology and of great importance for ecosystems management. Despite of being a relatively young discipline, the classical concepts of restoration seem, at present, impractical considering the great challenges generated by modification and destruction of ecosystems. This is due to anthropic activities (deforestation, change of land use, pollution) and global climate change. In the classic definition of restoration, the objective is to recover the degraded ecosystem to the same conditions of a historical reference state. However, nowadays the ecosystems return to a state prior to the disturbances seems unviable, because the thresholds of resilience have already been overcome. Additionally, climate change is causing environmental changes at an unprecedented rate. For this reason, ecological restoration needs to unite efforts of diverse actors to recover ecosystems that can be sustainable and functional in the future, where the species could be able to tolerate the environmental conditions that will exist in the long term. Assisted migration has been proposed as a conservation strategy; it is defined as the translocation of species to new locations outside their known range of distribution. In the current context of loss of diversity and ecosystems, this strategy could be fundamental for the formation of new communities that can later become novel ecosystems where species that are fundamental to the dynamics of ecosystems can persist and, at the same time, recover function, structure and resilience.
... HENRY FRANKLIN HOWE AND CRISTINA MARTÍNEZ-GARZA his challenge, but face practical problems of small scale of experiments and no budgetary support for long-time monitoring (Michener, 1997). Assisted regeneration that creates heterogeneity and connectivity between habitat remnants is more likely to restore diversity and ecosystem services in a timely fashion than slow natural succession, plantation monocultures or trial and error restoration. ...
Article
Full-text available
Large-scale ecological restoration generally employs un-replicated trial and error to re-create habitats destroyed or degraded by human activity. Trial and error follows a management plan that employs the "best available practice" for each habitat type; adaptive management reflecting experience subsequently corrects errors. The process is slow because each restoration is often well-advanced before adjustments are attempted. Rare are simultaneous replicated trials during the initial restoration or corrective process. "Systemic experimental restoration" would design replicated planting or management contrasts at the outset of large-scale public and commercial restorations. Alternative treatments create mosaics of different manifestations of a community within a mosaic of habitat types. Replicated contrasts within habitats allow the inference of cause and effect of success and failure on scales of communities, landscapes and ecosystems. For the long-term development of restoration ecology as a science, semi-natural communities of known contrasting histories will be important to encourage managers or investigators to create additional projects beyond explicit management or scientific objectives of an initial management plan. By consciously, integrating heterogeneity throughout restoration management plans, systemic mosaics of treatments within and between habitats, would facilitate multiple habitat responses to unpredictable changes in climate and land use.
... In general, conifer removal can prevent displacement and fragmentation of sagebrush systems, reduce available avian predator perches and nesting habitat, and improve range conditions[8,[21][22][23], but it is not confirmed that sage-grouse benefit from these treatments and determine the time frame of the response. A key step in ecological restoration is monitoring management outcomes[24,25], and experimentally evaluating restorative actions is an important step in understanding their efficacy[26]. Even more rare is monitoring demographics of the focal species after habitat restoration[27]. ...
Article
Full-text available
Sagebrush (Artemisia spp.) obligate wildlife species such as the imperiled greater sage-grouse (Centrocercus urophasianus) face numerous threats including altered ecosystem processes that have led to conifer expansion into shrub-steppe. Conifer removal is accelerating despite a lack of empirical evidence on grouse population response. Using a before-after-control-impact design at the landscape scale, we evaluated effects of conifer removal on two important demographic parameters, annual survival of females and nest survival, by monitoring 219 female sage-grouse and 225 nests in the northern Great Basin from 2010 to 2014. Estimates from the best treatment models showed positive trends in the treatment area relative to the control area resulting in an increase of 6.6% annual female survival and 18.8% nest survival relative to the control area by 2014. Using stochastic simulations of our estimates and published demographics, we estimated a 25% increase in the population growth rate in the treatment area relative to the control area. This is the first study to link sage-grouse demographics with conifer removal and supports recommendations to actively manage conifer expansion for sage-grouse conservation. Sage-grouse have become a primary catalyst for conservation funding to address conifer expansion in the West, and these findings have important implications for other ecosystem services being generated on the wings of species conservation.
... Field manipulations are generally labor intensive and have been criticized because they are often not replicated adequately or correctly for statistical analysis (Hurlbert 1984, Cooper and Barmuta 1993, Carpenter et al. 1998). These experimental approaches may be supplemented by using survey data in a ''space for time '' substitution (Stromberg et al. 1996, Flower et al. 1997, Michener 1997 where samples from many sites spanning gradients of ecological condition and natural environmental variation in a region are analyzed. While such survey data are often complex, multivariate statistical methods can reduce this complexity and extract patterns at regional spatial scales that are relevant to environmental management (Omernik 1995). ...
Article
Full-text available
Using redundancy analysis (RDA) and canonical correspondence analysis (CCA), we assessed relationships among chemical and physical characteristics and macroinvertebrate assemblages at stream sites sampled by the Regional Environmental Monitoring and Assessment Program (R-EMAP) in the mineral belt of the Southern Rockies Ecoregion in Colorado. We contrasted results of analyses where community structure was summarized as community metrics and analyses based on genera abundances. Our objective was to identify metrics or taxa diagnostic of major environmental stressors in these streams. When RDA was used to analyze the community metrics data, three axes were significant, accounting for 96% of the metric-environment relation. The first RDA axis was correlated with dissolved cadmium, sediment zinc, and total suspended solids, variables that indicate it was related to mining effects. The second and third RDA axes were correlated with water temperature, mean substrate embeddedness, mean canopy density at the banks, and a riparian human disturbance index for agriculture, variables associated with riparian and substrate alterations associated with grazing by livestock. When CCA was used to analyze the genera abundance data, four axes were significant, accounting for 45% of the species-environment relation. The CCA axes were correlated with total and dissolved iron, water temperature, dissolved and total organic carbon, mean bank height, and mean water surface gradient, variables associated with riparian disturbance from livestock grazing, but not with mining effects. Because CCA measures variation in community structure in terms of changes in the absolute abundances of different genera relative to one another, that analysis of genera abundances was sensitive to the effects of riparian disturbance and stream size, but not to the general toxicological effects associated with mining that reduced the abundances of all genera. Community metrics measure various aspects of community structure, including taxa richness, taxa relative abundances, and taxa relative dominance, and these metrics were sensitive to the effects of mining, riparian disturbance, and stream size. Some community metrics, such as the percentage abundance of the most dominant taxon, the total number of individuals, the total number of taxa, and the number of chironomid taxa, may be used to diagnose the environmental stressors in these streams, while the results of the CCA for genera abundances may be used to design new metrics for this purpose.
... Caution should be taken with short-duration studies, since the lack of detecting an effect may be from a study design that is not strong enough to detect an effect, rather than the lack of an effect from the management practice (Lindenmayer 1999). Studies with an insufficient duration (or presumably not enough sites) risk misinterpreting results and the ability to predict responses to disturbances (Michener 1997). ...
... Treating sample plots as independent observations allows for the comparison of different plantations (Sansevero et al. 2011). Such chronosequences provide a cost-effective and quick method for investigating forest change over time (Letcher & Chazdon 2009) and are generally used in restoration project comparisons where no replication across the landscape is possible since replicate sites might not exist (Hurlbert 1984;Michener 1997;Block et al. 2001;Guilliam 2002). More practically, finding other sites with similar environmental conditions or restoration models for comparison is very difficult in the study area, and the approach used is the only way to gain insight into long-term trends. ...
Article
Full-text available
Questions: Do different growth forms have distinct temporal patterns of recovery of their structure, diversity, and composition in restored Atlantic Rain forest? Are tree and non-tree assemblages structured by the same factors? Location: Atlantic Rain Forest, restored by planting an assemblage of highdiversity tree species, Brazil. Methods: We measured plant colonization of restoration sites of different ages to evaluate restoration success in terms of species diversity, colonization by non-tree species and structure measures among stands. We used Procrustes analysis to test whether the same conditions that influence tree composition influence non-tree composition (congruence between non-trees and trees present on the same sites). Results: Many structural aspects of recovering forests, e.g. tree basal area, canopy cover, height, tree richness, and non-tree floristic composition resembled a mature forest within five decades. Although tree species diversity increased according to restoration age of sites, planted sites did not recover the richness of all growth forms even after five decades of restoration, and particularly lacked climbers and epiphytes. We detected significant similarity between corresponding points (tree and non-tree composition) from separate ordinations only in the reference forest. Therefore, naturally assembled communities are more concordant than those originating from active restoration. Conclusion: Non-tree assemblages respond to different factors than the tree assemblages in restoration sites. Hence, non-tree recovery may not result as a natural consequence of tree recovery, and specific restoration strategies for non-tree species must be applied. Tree richness recovered after two decades. Only half of the non-tree species richness was recovered in old restoration sites, but their composition similarity reached expected levels of reference values. Further studies will investigate if low richness of non-tree species is a consequence of low input of allochthonous propagules (landscape filter) or whether they are arriving but not establishing (environmental filter). Enrichment planting of non-tree species may be required if the problem is propagule input. We recommend enrichment planting should be implemented within 10 yrs after initial restoration planting because of the need for trees as supporting structures. However, if propagules are arriving but not establishing, the solution is to detect which environmental filters are important and to manipulate them through forest management.
... El monitoreo de la efectividad ecológica de las ER (Block et al. 2001) se articuló a su formulación considerando aspectos como la disposición y cantidad de unidades de respuesta, la orientación cardinal y las secuencias de implementación de siembras para obtener unidades homogéneas estandarizadas e independientes, pertinentes para la toma eficiente de datos y la colección de información robusta (Michener 1997). Se seleccionaron parámetros e indicadores con base en la lista propuesta por Holl y Cairns (2002) para el monitoreo de proyectos de RE y se estableció la periodicidad para su seguimiento el corto plazo en cinco años. ...
Conference Paper
Full-text available
En Colombia, de la extensión original del bosque seco tropical (Bs-T) actualmente queda el 8% y tan sólo el 0.4% se encuentra bajo alguna figura de protección. En los valles interandinos del río Magdalena (Departamento del Huila) se desarrolla el Plan Piloto de Restauración del Bs-T del proyecto hidroeléctrico El Quimbo, el cual busca definir las estrategias de restauración ecológica más exitosas desde el punto de vista ecológico y económico. Se realizó una zonificación de unidades ecológicas homogéneas en función de la cobertura vegetal, la pendiente y los ecosistemas de referencia, las cuales permitieron guiar los objetivos de restauración. En cada una de las siete unidades de manejo se diseñaron e implementaron cuatro estrategias de restauración: tres estrategias combinan actividades de intervención (restauración activa) y la otra detiene los disturbios antrópicos para permitir y monitorear el proceso de restauración pasiva. En cada estrategia se realizan intervenciones físicas, de hábitat y biológicas. Las actividades físicas buscan reducir la erosión del suelo y superar el déficit hídrico, las de hábitat dan refugio a la fauna y aumentan el flujo de semillas y las bióticas promueven los procesos sucesionales. En los pastizales las estrategias de rehabilitación buscan recuperar los procesos ecosistémicos y los servicios ambientales del ecosistema. En los arbustales y bosques las estrategias de restauración buscan superar los umbrales y aumentar su integridad ecológica. La efectividad de las estrategias se determinará a través del monitoreo de aumento de la integridad ecológica y la recuperación de la conectividad y los servicios ecosistémicos.
... Intact bottomland hardwood forests are among the list of endangered ecosystems in the United States; in the past 50 years, losses of these forest have at times been greater than 120,000 ha per year ( MacDonald et al. 1979, as cited in King 1996. This survey was undertaken in order to analyze and classify a remnant bottomland forest, the results of which can be used to assist future ecological management and restoration of these disappearing ecosystems ( Shear et al. 1996;Michener 1997). ...
Article
A remnant bottomland hardwood forest near Denton, Texas was surveyed in order to describe its phytosociological composition. Hackberry, cedar elm and green ash dominate the site with respect to basal area, density and frequency in the forest. Importance values for these three dominant species are 40%, 28% and 10%, respectively. Snag density was found to be 57 per hectare. Cluster analyses of plot metrics indicate a patchy forest. Many trees were found to be well over 200 years old, indicating that the forest predates any significant Anglo settlement. These results indicate that the forest may be classified as transitional old-growth of the hackberry/elm/ash forest type. Because of its unique status as a relatively intact north Texas bottomland hardwood forest, the data obtained from this site can be used for comparisons with other bottomland forests, and as a guideline for future restoration efforts throughout the northwestern region of the southern bottomland forests.
... Several papers have outlined general concepts and theory for developing a restoration 51 experiment to evaluate effects on wildlife, including an array of analytical approaches and a 52 multitude of pitfalls and barriers to successful experiments (Michener 1997, Chapman 1998, 53 Block et al. 2001. Despite this guidance, experiments evaluating wildlife responses to habitat 54 restoration remain rare, and likely have been hampered by financial and logistical constraints 55 combined with fear of failure (Aslan et al. 2013, Dickens andSuding 2013). ...
Preprint
Full-text available
Experimenting with new and unconventional restoration methods and designs is critical to advancing the field of ecological restoration. Conventional methods cannot be considered reliable in a future with climate change-induced shifts in weather conditions, species distributions, and ecosystem processes. It is crucial that researchers and practitioners collaborate to identify the most effective restoration methods, yet there remains a disturbing lack of restoration experiments at the spatial or temporal scales relevant for evaluating wildlife responses. We suspect that willingness to attempt such experiments is hampered by the perceived difficulty of conducting these experiments combined with a fear of failure. However, we argue that failure to experiment with new methods guarantees learning nothing new. Here, we address many of the major challenges of designing an experiment to evaluate wildlife responses to restoration, including (1) distinguishing between the goals and objectives of the restoration project and the key uncertainties the experiment will address, (2) designing the experiment itself, including optimizing plot size and replication, and (3) determining how and when the results will be evaluated. We then illustrate how we designed an experiment to evaluate riparian bird responses to restoration along the lower Cosumnes River in the Central Valley of California, USA. Researchers and practitioners working together from the start of the objectives-setting process, through experimental design, implementation, and evaluation can proactively address the challenges of conducting a restoration experiment and maximize the chances of successfully identifying effective restoration methods, adding to the practitioners’ toolbox, and accelerating the rate of successful habitat restoration.
... To examine the temporal trend of NUE time series data, we used models with autoregressive moving average residuals (Box et al., 2015) to account for temporal autocorrelation. Temporal autocorrelation occurs when unexplained variation at one time step has lingering effects over additional time steps (Ives et al., 2010;Michener, 1997); thus, if events that affect NUE in one year have lasting effects in subsequent years, they may generate autocorrelation. In our time series models, "unexplained variation" refers to any variation not captured in the trends of NUE, which are explicitly included in the model. ...
Article
Full-text available
Vegetation phenology directly reflects the response of ecosystem physiological and ecological processes to environmental changes and has received increasing attention in climate change, which leads to the development of various phenology monitoring techniques and methods of extracting the phenological index. Based on relevant literatures, the monitoring techniques of vegetation phenology were reviewed. Second, the methods of extracting phenological index using different techniques were introduced systematically. Thirdly, the differences from multi-source data and from multi-methods were evaluated based on ground phenology record, flux observation and vegetation index. Although various methods have been adopted in current vegetation phenological studies, it should be aware of their appropriately spatiotemporal scales for different methods, and the mutual complementation will help to improve the system for phenology monitoring. Meanwhile, the comparison indicated the obvious differences in derived vegetation phenological index using various observation techniques and extraction methods, especially for the autumn vegetation phenological index. Such results highlight the importance to assess reasonably these differences from multi-source data and from multi-methods, and to establish a rational processing system for the mutual comparison and conversion from different methods.
... Postrestoration appraisals enable critical, comparative evaluation of restoration techniques (Downs & Kondolf, https://doi.org/10.33256/32.1.1426 2002; Skinner et al., 2008), guide future management decisions, and help reduce uncertainties in contemporary applications (Michener, 1997;Skinner et al., 2008;Loflen et al., 2016). Monitoring is required to track progress along the recovery trajectory, implement corrective actions, and provide feedback on ecosystem state and restoration interventions, thereby inform future actions (Choi, 2004;Klemas, 2013). ...
Article
Full-text available
Wetlands perform critical ecological functions and provide wildlife habitats. Yet, wetland degradation continues at a global scale. In Massachusetts, USA, wetland restoration has reached remarkable heights, partly promoted by the retirement of cranberry bogs. In this study, to assess the effectiveness of cranberry-farm restoration for conservation of native herpetofauna, we surveyed both retired and restored cranberry bogs in southeastern Massachusetts. Using both visual encounter surveys and baited aquatic traps, we documented herpetofaunal species and their relative abundance. Both survey methods combined, the cumulative herpetofaunal species richness at the restored bogs (16) exceeded that of the retired bogs (11). Our trap surveys indicated that the amphibian species richness at the retired bog was significantly greater than that of the restored bog. In contrast, reptilian species richness as well as the relative abundance of both amphibians and reptiles were significantly greater at the restored bog compared to the retired bog. Subsequent analyses we performed identified that greater habitat heterogeneity emerging from active restoration intervention was the underlying driver of elevated richness and abundance. Most frequently encountered herpetofauna at the restored versus retired bogs were habitat generalists with broader geographic ranges and are not of conservation concern. Our findings suggest that the restored bog we monitored is still in the early-recovery phase after active intervention. We urge the need for long-term herpetofaunal inventories via systematic, standard surveys to assess restoration success.
... The selection of our sampling sites allows for a spacefor-time substitution approach (Pickett, 1989;Michener, 1997) with respect to restoration measures. The spatial differences between the natural, unimpacted shore site KBN, the armoured shore site HGM and the restored shore site HGR can be also thought of as a temporal succession of events: a natural shore (KBN) would be anthropogenically modified (HGM) and subsequently restored back to a near-natural state (HGR). ...
Article
Full-text available
The littoral zones of many Central European lakes are severely altered by lake-side retaining walls. These are suspected to impair littoral biota due to the reflection of incoming wave energy. We conducted a comparative study (armoured shore with a retaining wall and a restored shore with a wedge-shaped cobble embankment vs. a pristine shore) at a wind-exposed shore section of Lake Constance. The retaining wall had a number of significant remote effects on the littoral zone, i.e. increased near-bottom current velocities, higher bed-load transport rates, coarsening of surface sediments, reduction in phytomass density, reduction in total densities and number of taxa of macroinvertebrates as well as a significant decline in the percentages of Limnomysis benedeni Czerniavsky, 1882, Ostracoda, Corbicula fluminea O.F. Müller, 1774, Dreissenapolymorpha (Pallas, 1771) and other Bivalvia. However, the significantly affected zone had a rather narrow width of ~ 3 m. Shore restoration measures are needed to remediate negative effects of retaining walls and re-establish ecological conditions that are comparable to those of pristine shores. We recommend a more site sensitive sampling strategy, e.g. for macroinvertebrates in context with the ecological quality assessment under the European Water Framework Directive.
... Who are these data for, if they are not to inform future research and move forward our broader ecological understanding of restoration? Bayesian methods offer an opportunity for data synthesis that can help ecologists integrate multiple sources of data (such as quantitative and qualitative data discussed by Michener 1997). Researchers have demonstrated that information obtained in observational studies can decrease uncertainty in analysis of experimental studies (McCarthy & Masters 2005) and the reverse may also be true when laboratory or manipulated studies Author contributions: CA wrote the paper; TTC, MJG edited the manuscript and provided conceptual feedback. ...
Article
Full-text available
There is an urgent need for near-term predictions of ecological restoration outcomes despite imperfect knowledge of ecosystems. Restoration outcomes are always uncertain but integrating Bayesian modeling into the process of adaptive management allows researchers and practitioners to explicitly incorporate prior knowledge of ecosystems into future predictions. While barriers exist, employing qualitative expert knowledge and previous case studies can help narrow the range of uncertainty in forecasts. Software and processes that allow for repeatable methodologies can help bridge the existing gap between theory and application of Bayesian methods in adaptive management. This article is protected by copyright. All rights reserved.
... Although it would not have eliminated the challenge, additional pre-restoration data would have been instructive in clarifying to what extent post-restoration trends deviated from pre-restoration trends. The lack of pre-restoration data and difficulties in selecting appropriate controls are especially common issues in assessments of environmental impacts, and the topic has been discussed in depth [e.g., 55,56,76]. ...
Article
Recent restoration efforts for the native Olympia oyster, Ostrea lurida, are commonly motivated by potential return of oyster-associated ecosystem services, including increased water filtration. The potential impact of such restoration on another species of ecological concern, eelgrass, Zostera marina, is unclear, but has been hypothesized to be positive if oyster filter feeding increases light penetration to eelgrass. For two years after construction of an oyster restoration project, we assessed the response of adjacent eelgrass (impact) compared to control and reference eelgrass beds by monitoring changes in light intensity, eelgrass shoot density, biomass, leaf morphometrics, and epiphyte load. We observed lower light intensity consistently over time, including prior to restoration, near the constructed oyster bed relative to the control and one of the reference locations. We also observed minor variations between control and impact eelgrass morphology and density. However, the changes observed were not outside the range of natural variation expected in this system, based upon comparisons to reference eelgrass beds, nor were they detrimental. This limited impact to eelgrass may be due in part to the incorporation of a buffer distance between the restored oyster bed and the existing eelgrass bed, which may have dampened both positive and negative impacts. These findings provide evidence that Olympia oyster restoration and eelgrass conservation goals can be compatible and occur simultaneously.
... This study design is commonly used for impact assessments and is considered a "quasi-experiment" because it lacks replication and random allocation of treatments (Stewart-Oaten et al. 1992, Block et al. 2001. Although the inference of quasi-experiments is limited, true experiments at large scales are often logistically and financially unfeasible (Michener 1997). The BACI design of this study followed the description of Block et al. (2001). ...
Article
Full-text available
Woody plant expansion into shrub and grasslands is a global and vexing ecological problem. In the Great Basin of North America, the expansion of pinyon–juniper (Pinus spp.–Juniperus spp.) woodlands is threatening the sagebrush (Artemisia spp.) biome. The Greater Sage‐grouse (Centrocercus urophasianus; sage‐grouse), a sagebrush obligate species, is widespread in the Great Basin and considered an indicator for the condition of sagebrush ecosystems. To assess the population response of sage‐grouse to landscape‐scale juniper removal, we analyzed a long‐term telemetry data set and lek counts with a Bayesian integrated population model in a before‐after‐control‐impact design. Population growth rates (λ) in a treatment area (Treatment) with juniper removal and a control area (Control) without juniper removal indicated the two areas generally experienced population increase, decrease, and stability in the same years. However, the difference in λ between study areas indicated a steady increase in the Treatment relative to the Control starting in 2013 (removals initiated in 2012), with differences of 0.13 and 0.11 in 2016 and 2017, respectively. Retrospective sensitivity analysis suggested the dynamics in λ were driven by increases in juvenile, adult, first nest, and yearling survival in the Treatment relative to the Control. These findings demonstrate the effectiveness of targeted conifer removal as a management strategy for conserving sage‐grouse populations in sagebrush steppe affected by conifer expansion. Examples of positive, population‐level responses to habitat management are exceptionally rare for terrestrial vertebrates, and this study provides promising evidence of active management that can be implemented to aid recovery of an imperiled species and biome.
... Thus, it was allowed to develop a descriptive research design. As referred by Kothari [67] and Michener [68], a structured survey allows us to quantify a multitude of data for further analysis. The use of the survey, as well as, the use of quantitative analysis of the data, with help of different statistical tools and methods, can be verified in a great variety of research work carried out under various studies about quality management, as well as, of its needs [69,70]. ...
Article
Full-text available
These transformations will change the industrial landscape, toward Quality 4.0 and therefore, our lives. The presented research was conducted on quality management employees in Portugal and it aims to analyze if such employees have the perception of the impact of Industry 4.0 in the quality management profession and the required and needed skills. After analyzing the answered questionnaires, 90 results were considered valid. This is the sample of our study. Simultaneously, the goal of this research is also to review and analyze the main topics in progress related to quality management for the fourth industrial revolution and how quality emerges of this change. The professionals that work on quality management must have creative thinking, be leaders, know how to communicate and work as a team, as well as, to have knowledge and understanding of ICT (Information and Communications Technology), and main pillars of Industry 4.0. These are the main findings. Besides that, they must know how to motivate their work teams, be open to change, know how to use Big Data to make decisions and above all, they must know how to manage conflicts. In addition, quality professionals must promote the design and production of first class products, be the defenders of their customers within the organization , and finally, they must create value for the stakeholders.
... Several papers have outlined general concepts and theory for developing a restoration 51 experiment to evaluate effects on wildlife, including an array of analytical approaches and a 52 multitude of pitfalls and barriers to successful experiments (Michener 1997, Chapman 1998, 53 Block et al. 2001. Despite this guidance, experiments evaluating wildlife responses to habitat 54 restoration remain rare, and likely have been hampered by financial and logistical constraints 55 combined with fear of failure (Aslan et al. 2013, Dickens andSuding 2013). ...
Preprint
Full-text available
Experimenting with new and unconventional restoration methods and designs is critical to advancing the field of ecological restoration. Conventional methods cannot be considered reliable in a future with climate change-induced shifts in weather conditions, species distributions, and ecosystem processes. It is crucial that researchers and practitioners collaborate to identify the most effective restoration methods, yet there remains a disturbing lack of restoration experiments at the spatial or temporal scales relevant for evaluating wildlife responses. We suspect that willingness to attempt such experiments is hampered by the perceived difficulty of conducting these experiments combined with a fear of failure. However, we argue that failure to experiment with new methods guarantees learning nothing new. Here, we address many of the major challenges of designing an experiment to evaluate wildlife responses to restoration, including (1) distinguishing between the goals and objectives of the restoration project and the key uncertainties the experiment will address, (2) designing the experiment itself, including optimizing plot size and replication, and (3) determining how and when the results will be evaluated. We then illustrate how we designed an experiment to evaluate riparian bird responses to restoration along the lower Cosumnes River in the Central Valley of California, USA. Researchers and practitioners working together from the start of the objectives-setting process, through experimental design, implementation, and evaluation can proactively address the challenges of conducting a restoration experiment and maximize the chances of successfully identifying effective restoration methods, adding to the practitioners’ toolbox, and accelerating the rate of successful habitat restoration.
... Restoration manipulations were only partially successful in Nizzanim LTER, but rodents seemed to respond most favorably. With respect to ecosystem functioning, "long-term" can mean anything from decades to centuries, so realistic expectations about restoration of sand dunes could take many years [141]. Over a longer timeframe, the response at the composition level may become more pronounced. ...
Article
Full-text available
Coastal dune habitats have been declining globally over the last several decades due to rapid urbanization. Within remaining dune systems, dune fixation has resulted in further losses of mobile dunes with negative impacts on their associated species. Some studies suggest vegetation removal can initially promote habitat heterogeneity, and increase availability of suitable habitats for psammophile, xeric and endemic mobile dune species, but longer-term responses are generally unknown. We investigated the temporal trends of four taxonomic groups to determine the effect of vegetation removal on dune assemblages over a 12-year period at an LTER site. Three different forms of removal are investigated here—removal in a grid form on fixed dunes, removal of the wind-facing slope vegetation on semi-fixed dunes and opportunistic off-road driving on disturbed dunes. Results were varied across taxa, highlighting the need for multi-taxa monitoring in conservation and restoration management. Overall, fixed dune treatment had very little effect, while a stronger response was found in semi-fixed treatments in particular for mobile dune indicator species, which showed evidence of recolonization within a few years following treatment. Disturbed dunes were most similar to mobile dunes for animal taxa indicating that pulse removal may not be as effective as continuous press disturbance. Nevertheless, a less destructive form of disturbance such as re-introduction of grazing might be preferable and requires further investigation.
... Like FMT studies, projects in restoration ecology commonly lack experimental and control treatments or are monitored insufficiently to identify causes of success and failure (Kondolf 1995;Michener 1997). Restoration ecology has been criticized for being ad hoc, site-specific, and conceptually ungrounded (Suding 2011). ...
Article
Full-text available
Dysbiosis of the gut facilitates chronic diseases such as cancer, obesity, and autoimmune disorders. Successful treatment may require restoration of functions performed by symbiotic microbes. The field of ecological restoration has restored species diversity and ecosystem function of natural habitats since the latter part of the 20th century, but its possible applications to medicine are unexplored. Here we show that approaches developed to restore natural ecosystems may aid in the treatment of chronic disease by helping to characterize target conditions for healthy microbe communities, by identifying the importance of donor diversity in fecal microbiota transplants, and by elevating the importance of diet, patient involvement, and personalized medicine in gut health. Dialogue between the fields of restoration ecology and medicine may help to guide future directions in gut research and clinical care.
... Thus, allowing to develop a descriptive research design. A structured survey allows to quantify a multitude of data for further analysis and relationships as referred by (Kothari, 2011;Michener, 1997). The use of the survey and the use of quantitative analysis of the data through different techniques and statistical methods can be observed in a variety of research work carried out under studies regarding quality management and its needs (Duran, 2014;Lam, 1995). ...
Article
Full-text available
Quality Management has been one of the most dominating and pervasive managerial approaches all over the world during the last three decades. The questionnaire of this study included different information, of where we can highlight: the perception of the importance having implemented the ISO 9001 standard; the most used quality tools/techniques in the professional activities. As main conclusions we can highlight: women attach great importance to the implementation of the ISO 9001 standard, namely as regards on customer satisfaction, in the competitiveness of the Organization and in the relationship with customers and give less importance in individual performance, in motivation of professionals and in the evolution of sales. Men value the implementation of the ISO 9001 more, namely regarding to the relationship with customers, in the management mode and they give less importance to the evolution of sales and to the motivation of professionals.
... Measuring the ecological benefits of ecoengineered shorelines requires prespecifying a monitoring framework (prior to initiation) that effectively assesses changes in a specific intervention or habitat of interest (Michener 1997, Block et al. 2001. Ideally, monitoring plans compare ecoengineered shorelines with controls (i.e. ...
Article
Full-text available
Human population growth and accelerating coastal development have been the drivers for unprecedented construction of artificial structures along shorelines globally. Construction has been recently amplified by societal responses to reduce flood and erosion risks from rising sea levels and more extreme storms resulting from climate change. Such structures, leading to highly modified shorelines, deliver societal benefits, but they also create significant socioeconomic and environmental challenges. The planning, design and deployment of these coastal structures should aim to provide multiple goals through the application of ecoengineering to shoreline development. Such developments should be designed and built with the overarching objective of reducing negative impacts on nature, using hard, soft and hybrid ecological engineering approaches. The design of ecologically sensitive shorelines should be context-dependent and combine engineering, environmental and socioeconomic considerations. The costs and benefits of ecoengineered shoreline design options should be considered across all three of these disciplinary domains when setting objectives, informing plans for their subsequent maintenance and management and ultimately monitoring and evaluating their success. To date, successful ecoengineered shoreline projects have engaged with multiple stakeholders (e.g. architects, engineers, ecologists, coastal/port managers and the general public) during their conception and construction, but few have evaluated engineering, ecological and socioeconomic outcomes in a comprehensive manner. Increasing global awareness of climate change impacts (increased frequency or magnitude of extreme weather events and sea level rise), coupled with future predictions for coastal development (due to population growth leading to urban development and renewal, land reclamation and establishment of renewable energy infrastructure in the sea) will increase the demand for adaptive techniques to protect coastlines. In this review, we present an overview of current ecoengineered shoreline design options, the drivers and constraints that influence implementation and factors to consider when evaluating the success of such ecologically engineered shorelines
... Measuring the ecological benefits of ecoengineered shorelines requires prespecifying a monitoring framework (prior to initiation) that effectively assesses changes in a specific intervention or habitat of interest (Michener 1997, Block et al. 2001. Ideally, monitoring plans compare ecoengineered shorelines with controls (i.e. ...
Chapter
Full-text available
Human population growth and accelerating coastal development have been the drivers for unprecedented construction of artificial structures along shorelines globally. Construction has been recently amplified by societal responses to reduce flood and erosion risks from rising sea levels and more extreme storms resulting from climate change. Such structures, leading to highly modified shorelines, deliver societal benefits, but they also create significant socioeconomic and environmental challenges. The planning, design and deployment of these coastal structures should aim to provide multiple goals through the application of ecoengineering to shoreline development. Such developments should be designed and built with the overarching objective of reducing negative impacts on nature, using hard, soft and hybrid ecological engineering approaches. The design of ecologically sensitive shorelines should be context-dependent and combine engineering, environmental and socioeconomic considerations. The costs and benefits of ecoengineered shoreline design options should be considered across all three of these disciplinary domains when setting objectives, informing plans for their subsequent maintenance and management and ultimately monitoring and evaluating their success. To date, successful ecoengineered shoreline projects have engaged with multiple stakeholders (e.g. architects, engineers, ecologists, coastal/port managers and the general public) during their conception and construction, but few have evaluated engineering, ecological and socioeconomic outcomes in a comprehensive manner. Increasing global awareness of climate change impacts (increased frequency or magnitude of extreme weather events and sea level rise), coupled with future predictions for coastal development (due to population growth leading to urban development and renewal, land reclamation and establishment of renewable energy infrastructure in the sea) will increase the demand for adaptive techniques to protect coastlines. In this review, we present an overview of current ecoengineered shoreline design options, the drivers and constraints that influence implementation and factors to consider when evaluating the success of such ecologically engineered shorelines.
... We included all reach-year samples in all analyses. While we recognize that including all temporal samples in subsequent analyses without identifying or controlling for temporal autocorrelation is not ideal, we emphasize that the treatment of these observational data was developed to conceptualize themes in fish trait responses to reach-scale habitat rather than use probabilistic methods to evaluate causal mechanisms with certainty (Michener 1997). This treatment of temporally replicated data collection is not uncommon in evaluations of fish-habitat associations that employ ordination techniques (e.g. ...
Article
Full-text available
Valley plug formation is a challenging consequence of stream channelization especially in physiographic regions with highly erodible soils. Upstream channel degradation and incision results in accelerated sediment delivery processes wherein downstream aggradation decreases stream power and creates sand‐clogged channels. Channel reconstruction is now meeting hydrogeomorphic goals related to valley plug remediation yet there exists a need to understand how this practice also facilitates ecological restoration. We evaluated fish trait response to in‐stream habitat conditions in channelized, recently restored, and ‘least‐disturbed’ reference reaches of Coastal Plains streams in West Tennessee. Restored reaches were ecologically similar to channelized reaches, having higher proportions of nest‐guarding omnivores that were correlated with higher percentages of pool habitats and lower wetted width:depth ratios compared to reference reaches. Reference reaches had higher proportions of fast‐water dwelling and specialized insectivores that were correlated with high abundance of large woody debris, high wetted width:depth ratios, and low percentages of pool habitats. We conclude that in‐stream habitats in reconstructed channels have yet to promote reach‐scale ecological restoration relative to fish assemblage organization because trait‐habitat associations were not similar to reference conditions. However, our results lend to the development of ecological restoration targets that can be incorporated in future channel reconstruction projects in valley‐plugged, channelized streams of the Coastal Plains. This article is protected by copyright. All rights reserved.
... To examine the temporal trend of NUE time series data, we used models with autoregressive moving average residuals (Box et al., 2015) to account for temporal autocorrelation. Temporal autocorrelation occurs when unexplained variation at one time step has lingering effects over additional time steps (Ives et al., 2010;Michener, 1997); thus, if events that affect NUE in one year have lasting effects in subsequent years, they may generate autocorrelation. In our time series models, "unexplained variation" refers to any variation not captured in the trends of NUE, which are explicitly included in the model. ...
Article
Full-text available
Abstract Spatial variation and temporal trajectory of crop nitrogen use efficiency (NUE) have important implications for nitrogen management and environmental conservation. Previous studies have examined cross‐nation divergences in crop NUE but often overlooked its spatial heterogeneity and cross‐crop differences at subnational scales. We examined the relationship between state‐level NUE and nitrogen fertilizer use for two major fertilizer‐consuming crops, corn and winter wheat, which account for over half of national N fertilizer use in the United States. Since 1970, as N fertilizer use rates have changed, the responses of crop yield and NUE have exhibited large temporal and spatial variations. It is evident that NUE of corn begins to decline when N fertilizer application rate exceeds ~150 kg N ha−1 yr−1, and that yield response of winter wheat slows down with annual N fertilizer input above ~50 kg N ha−1 yr−1. State‐level NUE in both crops has risen in recent decades, which could potentially reduce N loss from agricultural production. Across the United States, some major corn‐producing states demonstrate a shift from an increasing trend of NUE during the period 1970 to 1999 to a decreasing trend after 2000, whereas winter wheat‐producing states present an opposite pattern. Furthermore, this study indicates that annual dynamics of N surplus in corn is closely tied with grain yields, while that in winter wheat significantly correlates with N fertilizer input. A larger proportion of N loss would be anticipated if no further increase in corn yield was obtained or fertilizer use kept rising in winter wheat.
... El monitoreo de la efectividad ecológica de las ER (Block et al. 2001) se articuló a su formulación considerando aspectos como la disposición y cantidad de unidades de respuesta, la orientación cardinal y las secuencias de implementación de siembras para obtener unidades homogéneas estandarizadas e independientes, pertinentes para la toma eficiente de datos y la colección de información robusta (Michener 1997). Se seleccionaron parámetros e indicadores con base en la lista propuesta por Holl y Cairns (2002) para el monitoreo de proyectos de RE y se estableció la periodicidad para su seguimiento el corto plazo en cinco años. ...
Article
Full-text available
El diagnóstico ecológico regional es fundamental para planificar procesos de restauración ecológica (RE), especialmente en ecosistemas poco conocidos y amenazados como el Bosque Seco Tropical (bs-T). A partir del diagnóstico ecológico de un bs-T en el departamento del Huila, Colombia, se formuló, implementó e inició el monitoreo de seis estrategias para su restauración. Para los escenarios de restauración se identificaron las barreras a la regeneración natural y sus facilitadores, los ecosistemas de referencia y las especies clave. Con esta información se formularon seis estrategias de restauración: i) nucleación en pastizales abiertos con núcleos entre 2x2 m y 32x32 m con variación en el número de especies (3–30), número de individuos (9–196), ensambles de especies (1–4) y manejo del suelo, ii) siembra bajo árboles nodriza en pastizales arbolados con 37 individuos de seis especies, iii) siembra bajo agrupaciones de árboles con 57 individuos de once especies, iv) ampliación de borde de bosques y arbustales con fajas de 10x5 m con 17 individuos de cinco especies, v) enriquecimiento en arbustales y bosques en módulos hexagonales monoespecíficos de siete individuos, y vi) restauración espontánea. La siembra total fue de 54 300 individuos con mayor esfuerzo en la nucleación de 32x32 m con 159 réplicas y 21 676 individuos. El monitoreo a largo plazo permitirá evaluar el desarrollo de trayectorias sucesionales acorde con las referencias y determinar el costo efectividad de las estrategias. Este proceso metodológico de diagnóstico ecológico, formulación, implementación y monitoreo de estrategias puede servir como guía importante para la RE del bs-T en otras localidades.
... Data management complexity increases for long-term and broad-scale comparative studies and assessments in which scientists from numerous disciplines can be involved for long periods to address a complex series of questions or hypotheses. This necessitates increased attention to adequate metadata, QA/QC, archiving, and methods standardization (Michener, 1997). ...
Technical Report
Full-text available
The Salton Sea, California’s largest lake, provides essential habitat for several fish and wildlife species and is an important cultural and recreational resource. It has no outlet, and dissolved salts contained in the inflows concentrate in the Salton Sea through evaporation. The salinity of the Salton Sea, which is currently nearly one and a half times the salinity of ocean water, has been increasing as a result of evaporative processes and low freshwater inputs. Further reductions in inflows from water conservation, recycling, and transfers will lower the level of the Salton Sea and accelerate the rate of salinity increases, reduce the suitability of fish and wildlife habitat, and affect air quality by exposing lakebed playa that could generate dust.
... Like FMT studies, projects in restoration ecology commonly lack experimental and control treatments or are monitored insufficiently to identify causes of success and failure (Kondolf 1995;Michener 1997). Restoration ecology has been criticized for being ad hoc, site-specific, and conceptually ungrounded (Suding 2011). ...
Preprint
Full-text available
Dysbiosis of the gut facilitates chronic diseases such as cancer, obesity, and autoimmune disorders. Successful treatment may require restoration of functions performed by symbiotic microbes. The field of ecological restoration has restored species diversity and ecosystem function of natural habitats since the latter part of the 20th century, but its possible applications to medicine are unexplored. Here we show that approaches developed to restore natural ecosystems may aid in the treatment of chronic disease by helping to characterize target conditions for healthy microbe communities, by identifying the importance of donor diversity in fecal microbiota transplants, and by elevating the importance of diet, patient involvement , and personalized medicine in gut health. Dialogue between the fields of restoration ecology and medicine may help to guide future directions in gut research and clinical care.
Article
Future crop yield increases are unlikely to keep pace with the dietary needs of a global human population expected to reach nine billion by 2050. This study used United States Department of Agriculture county‐level yield data and autoregressive moving‐average models to examine how changes in maize (Zea mays L.), soybean (Glycine max L.), and winter wheat (Triticum aestivum L.) yields, temporal variability in yields, and yield gaps have varied across space and time from 1970–2017. The majority of county‐level yields have increased linearly, although the increases in wheat lag behind corn and soybean. Where trends were nonlinear, accelerating yields were found in more mesic regions east of the Great Plains, and decelerating yields were found in the drier central and western United States. Mean crop yields were positively correlated with rate of yield increase and negatively correlated with interannual variability. Hotspots were identified in Minnesota, Iowa, Illinois, Nebraska, and some West Coast states where crop yields are currently the largest, have the lowest yield gaps, and since 1970, have had the highest rates of change and/or are experiencing an acceleration of annual yield gains. Across all crop types, the counties with the lowest average yields, highest yield gaps, lowest rates of yield increase over time, and/or deceleration in yield increases were predominantly found in the central United States, including the Dakotas, Kansas, Oklahoma, and Texas. Regions of greatest performance generally have fertile soils, plentiful growing season rainfall, and optimal growing season length and temperatures, or are benefitting from irrigation.
Article
Full-text available
We compared the mollusc assemblages of planted mono-specific Rhizophora mangroves of known different ages. As forest age increased, there was a shift in species composition, abundance and biomass of mollusc assemblages for all faunal types (infauna, epifauna and arboreal fauna). This shift was correlated with the changes in vegetation (increasing forest cover and above-ground biomass) and sediment characteristics (increasing organic matter and decreasing sand content). Some species dominate in young plantations (<10 years old; Pirenella cingulata) and in intermediate plantations (10–15 years old; Nerita polita), while other species only occur in mature plantations and natural mangrove stands (>15 years; Terebralia sulcata, Nerita planospira). The two former groups of species are mostly species of infaunal and epifaunal habitats, while the latter group is mainly composed of arboreal species. The shift in mollusc species composition and dominance may serve as a useful indicator of restoration patterns in planted mangroves.
Chapter
The extent and state of ecosystem health of Philippine mangroves are affected by the occurrences of typhoons (ca. 20 per year). While severe damages (and sometimes even total forest collapse) are commonly reported, there are some cases where mangroves are less damaged and easily recovered implying that some mangroves are either highly vulnerable or resilient. Most studies on effects of typhoons in mangroves (including post-typhoon recovery) are mainly focused on vegetation but rarely on changes in sediment and faunal composition and activities. Also, these studies are mostly short-term and rapid (<1 year) with suboptimal experimental designs because of the lack of baseline data and systematic assessment. In this study, a 15-year synthesis of impacts of typhoon and post-typhoon recovery in selected mangrove sites in the Philippines was discussed and compared with other typhoon-disturbed tropical/subtropical mangroves. The study covered pre- and post-typhoon changes in vegetation, sediment, and faunal assemblages and activities including the assessment of possible recovery and identification of recovery indicators. The study provides an overview of interrelationships of vegetation, sediment (including nutrients), and faunal assemblages and activities as a more integrative approach in damage and recovery assessments. Lastly, the implications of the study on research needs (e.g., systematic and sustained monitoring) and policy and management programs (e.g., effective conservation and restoration programs) for Philippine mangroves were discussed.
Article
While best practices for evaluating restoration ecology projects are emerging rapidly, budget constraints often limit post‐restoration monitoring, which emphasizes the need for practical and efficient monitoring strategies. We examined the post‐restoration outcome for an ENGO (Nature Conservancy of Canada) project, to assess retroactively how variation in intensity and frequency of sampling would have affected estimates of plant species composition, diversity and richness over time. The project restored four habitat types (mesic forest, oak woodland, wet meadow and sand barren) using sculptured seeding of tallgrass prairie and woody species. Species level plant cover was monitored annually for 10 years in 168 2×2 m quadrats. We performed randomization tests to examine estimates of species diversity and richness as a function of the number of quadrats sampled, and assessed the necessity of annual sampling for describing changes in species composition and successional trajectories. The randomization tests revealed that sampling 10‐17 quadrats, depending on habitat type, was sufficient to obtain estimates of species diversity that were at least 95% of values obtained from the whole data set. Species richness as a function of number of quadrats sampled did not plateau, which suggests that rather than increasing the number of sampling quadrats, richness could be estimated more efficiently using non‐quadrat based sampling techniques. Non‐metric multidimensional scaling analysis revealed that plant species composition largely stabilized by 3‐5 years post‐restoration depending on habitat type. By that time, native, seeded species dominated the restoration, and the benefits of annual sampling for tracking changes in species composition diminished. This article is protected by copyright. All rights reserved.
Chapter
Arthropods represent the most diverse group of organisms on the Colorado Plateau and throughout the Southwest, yet relatively little effort has been directed toward th inventory and monitoring of arthropods on the Colorado Plateau as compared to vascular plants and vertebrate animals. For scientists and natural resource managers to understand biotic diversity, biotic communities, and ecosystem processes on landscapes of intere t, they need to conduct arthropod inventory and monitoring studies. Arthropod inventory and monitoring present challenges due to the tremendous diversity of taxa, but those challenges can be resolved through careful planning. Inventory and monitoring protocols for plants and vertebrate animals are readily available, but no such resources are available for arthropods. This article presents an approach and protocols to planning and implementing landscape-scale arthropod inventory and monitoring projects in semiarid regions. Unlike plant and vertebrate inventory and monitoring, arthropod inventory and monitoring usually requires the recruitment of outside taxonomic experts for consultation relative to the selection of target taxa, advice for appropriate sampling protocols, and specimen identification. Arthropod inventory and monitoring also should include collaboration ith a regional arthropod research museum to develop and archive voucher and reference specimen collections. Aspects of inventory and monitoring that are unique to arthropods are discussed, and an overall step-wise conceptual model to arthropod inventory and monitoring is presented.
Chapter
Full-text available
Estuaries are transitional ecosystems at the interface of the terrestrial and marine realms. Their unique physiographic position gives rise to large spatial variability, and to dynamic temporal variability resulting, in part, from a variety of forces and fluxes at the oceanic and terrestrial boundaries. River flow, in particular, is an important mechanism for delivering watershed-derived materials such as fresh water, sediments, and nutrients; each of these quantities in turn directly influences the physical structure and biological communities of estuaries. With this setting in mind, we consider here the general proposition that estuarine variability at the yearly time scale can be caused by annual fluctuations in river flow. We use a “long-term” (15-year) time series of phytoplankton biomass variability in South San Francisco Bay (SSFB), a lagoon-type estuary in which phytoplankton primary production is the largest source of organic carbon (Jassby et al. 1993).
Chapter
Full-text available
Ordered categorical (or semi-quantitative) data are frequently encountered in ecology (e.g., Steen et al. 1990; Ménard et al. 1993). Researchers often resort to semi-quantitative measures (to describe abundance patterns, age or stage structures, environmental factors, etc.) to reduce processing time and/or because of financial constraints, while retaining an acceptable level of accuracy.
Data
Full-text available
Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. The JSTOR Archive is a trusted digital repository providing for long-term preservation and access to leading academic journals and scholarly literature from around the world. The Archive is supported by libraries, scholarly societies, publishers, and foundations. It is an initiative of JSTOR, a not-for-profit organization with a mission to help the scholarly community take advantage of advances in technology. For more information regarding JSTOR, please contact support@jstor.org.
Article
Full-text available
There may be problems concerning the appropriate design of sampling programs to assess the impact upon the abundance of biological populations of, for example, the discharge of effluents into an aquatic ecosystem at a single point. Key to the resolution of these issues is correct identification of the statistical parameter of interest, which is the mean of the underlying probabilistic 'process' that produces the abundance, rather than the actual abundance itself. An appropriate sampling scheme was designed to detect the effect of the discharge upon this underlying mean. Detection of the effect of the discharge is achieved by testing whether the difference between abundances at a control site and an impact site changes once the discharge begins. -from Authors
Article
Full-text available
Separate modeling of the spatial mean field, the spatial variance field, and the space-time residual fields can give a more detailed and possibly more accurate representation of spatial interpolation errors when we have repeated observations on a fixed monitoring network. This article gives expressions for the spatial interpolation errors in terms of the statistics of the component fields, which enable us to assess the relative importance of different kinds of uncertainty. This modeling approach is applied to data of sulfur dioxide concentrations in Europe, and a comparison with neighborhood kriging is done by means of cross-validation.
Article
Data of understood quality, free from introduced errors or biases, are critical for analyses that aim to isolate subtle trends or patterns related to disturbance, succession or ecosystem evolution. As data accrue, the demand for data-driven, statistically based quality control techniques increases. A data quality control method for long-term environmental data that emphasizes statistical data visualization is described. Traditional parametric modelling is compared with semiparametric smoothing techniques using the Akaika Information Criterion (AIC) for model selection. An interface in development fits a series of parametric and semiparametric models, selects the minimum AIC fit, returns graphical output and estimates the potential intervention points. -Authors
Article
The primary goal of the long-term ecological research programme at Konza Prairie is to understand how grazing influences biotic and ecosystem processes and patterns imposed by fire frequency over the landscape mosaic, all of which are subjected to a variable (and possibly directional) climatic regime. A vital component of the research programme has been the development of the Konza Prairie LTER Research Information Management Program with the overall objectives of assuring data integrity, providing security for the database, and facilitating use of data by the original investigator(s) as well as by future investigators. Programme development has benefited from experiences gained through various administrative changes associated with Konza Prairie, growth of the research programme on Konza Prairie (especially in the fields of remote sensing and geographical information systems (GIS)), knowledge gained from other multidisciplinary research efforts (i.e., other LTER sites and First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE), and with changing computer technology. -from Authors
Article
The fifteen contributions show the formidable difficulties inherent in predicting the consequences of ecosystem changes, noting the use but also limitations of historical records and simulation models. The way forward is envisioned as being through long-term experimental manipulation of whole ecosystems. Such experiments would not only show how whole sytems, as well as their component elements, might respond to both short- and long-term change, but would also serve as tests for simulation models. Chapters, all abstracted separately, are on: El Nino; atmosphere-forest interactions and Amazon Basin deforestation; lessons from deforestation processes in the past; desertification; acid rain and forest ecosystems; uncontrolled ecosystem experiments with inorganic and organic micropollution; whole-lake experiments at the Experimental Lakes Area; fire and stream water chemistry; acidification; wetland ecosystems; forested watershed disturbance; mathematics of complex systems; aquatic ecosystem experiments in the context of global climatic change; whole-terrestrial ecosystem experiments; available technologies for field experimentation with elevated CO2 in global change research. (See 93L/11129, 11130, 11318, 11319, 11447-11449, 11453, 12022, 12064, 12065, 12109, 12200 and 12251). -P.J.Jarvis
Article
Exphasizes scientific problems requiring the scale and understanding that can be obtained only by the power of whole-ecosystem experiments. Assessments and recommendations are presented for discrete system types but include the assumption that many important changes in aquatic systems will derive from changes in the terrestrial systems located "upstream' in the hydrologic cycle. -from Authors
Article
Whole lake experiments have included eutrophication; acidification; pollution with radioactive materials and trace metals; and, very recently, a beginning in food chain manipulations. ELA work has also examined the effects of watershed changes on lakes, either by deliberately modifying watersheds (for example, wetland acidifications) and the clearcutting of forests. -from Author
Article
Much of the information managed for environmental analysis has a spatial component, which is critical in integrating one source with another. Recent standards efforts around the world (particularly the US Spatial Data Transfer Standard (SDTS)) specify the kind of information (data about the data or metadata) required to evaluate the data quality of some spatial data product. The SDTS requires that a data producer provide a Data Quality Report, which includes the lineage, positional accuracy, attribute accuracy, logical consistency and completeness of the data. Many of these elements of the report can be transmitted in the form of spatial distributions. A potential user should be able to peruse the Data Quality Report and render an informed judgement about the fitness of the data for the projected use. The Vector Product Format (designed for the public domain Digital Chart of the World), when compared with SDTS, shows particular improvements in implementing the original goals of including information to evaluate fitness for use. One key element is the treatment of metadata as spatial data in their own right. -Author
Chapter
The effects of nutrients and herbivory on phytoplankton biomass and production were examined, using data from 25 lakes studied for 2 to 6 years each. Variance among lakes was substantially greater than variance among years, for all physical, chemical, phytoplankton, and zooplankton variates studied. Experimentally manipulated lakes had coefficients of variation within the range exhibited by nonmanipulated lakes. Graphical, correlative, and regression analyses illustrated the significant joint effects of both nutrients and herbivory on phytoplankton biomass and production. A Bayesian analysis of sensitivity to new information showed that the statistical models for chlorophyll are quite robust. Statistical models for primary production were deemed less conclusive, because primary production was measured in fewer lakes. We provide a list of common challenges in comparative statistical analysis of ecosystems and explain their implications for our study. The major pattern apparent in our data—that summer chlorophyll responds positively to nutrients and negatively to herbivore size — is congruent with results of whole-lake experiments in which nutrients or predators were manipulated.
Chapter
Numerous, irrefutable examples of the central role that long-term studies play in ecology now exist (see, e.g., Likens, 1983; Strayer et al., 1986). There is increasing recognition that, because most important questions in ecology ultimately deal with predicting ecosystem responses, testing the correctness of ecological concepts and predictions by observing the future is essential. There are many sophisticated predictive models and general constructs, but few have actually been tested against data. In the final analysis, the most convincing validation comes only from such tests against reality.
Chapter
Are retrospective studies useful as supplements to long-term ecological studies? Can they serve as substitutes? Retrospective studies have often addressed the same sorts of problems as long-term studies. These include obtaining baseline data for comparison with modern observations, observing very slow processes, and measuring community and ecosystem responses to rare events (Strayer et al., 1986).
Article
Issues related to data preservation and sharing are receiving increased attention from scientific societies, funding agencies, and the broad scientific community. Ecologists, for example, are increasingly using data collected by other scientists to address questions at broader spatial, temporal, and thematic scales (e.g., global change, biodiversity, sustainability). No data set is perfect and self-explanatory. Ecologists must, therefore, rely upon a set of instructions or documentation to acquire a specific data set, determine its suitability for meeting specific research objectives, and accurately interpret results from subsequent processing, analysis, and modeling. 'Metadata' represent the set of instructions or documentation that describe the content, context, quality, structure, and accessibility of a data set. Although geospatial metadata standards have been developed and widely endorsed by the geographical science community, such standards do not yet exist for the ecological sciences. In this paper, we examine potential benefits and costs associated with developing and implementing metadata for nongeospatial ecological data. We present a set of generic metadata descriptors that could serve as the basis for a 'metadata standard' for nongeospatial ecological data. Alternative strategies for metadata implementation that meet differing organizational or investigator-specific objectives are presented. Finally, we conclude with several recommendations related to future development and implementation of ecological metadata.
Chapter
The ecological world is a multi-causal system in which patterns result from the direct effects of physical factors, from intraspecific and interspecific biotic interactions, and from indirect and feedback effects of one species or system element on another. As such, there is no single, simple approach that can ever unambiguously demonstrate how or why a particular process, physical factor, or species has an effect on another element of the ecosystem. Although this chapter will critically evaluate the potential contributions of experimentation to ecological understanding, I must stress at the outset that ecological research requires a synthetic approach in which observational, experimental, and theoretical approaches are pursued in a simultaneous, coordinated, interactive manner.
Article
Ecological studies typically involve comparison of biological responses among a variety of environmental conditions. When the response variables have continuous distributions and the conditions are discrete, whether inherently or by design, then it is appropriate to analyze the data using analysis of variance (ANOVA). When data conform to a complete, balanced design (equal numbers of observations in each experimental treatment), it is straightforward to conduct an ANOVA, particularly with the aid of the numerous statistical computing packages that are available. Interpretation of an ANOVA of balanced data is also unambiguous. Unfortunately, for a variety of reasons, it is rare that a practicing ecologist embarks on an analysis of data that are completely balanced. Regardless of its cause, lack of balance necessitates care in the analysis and interpretation. In this paper, our aim is to provide an overview of the consequences of lack of balance and to give some guidelines to analyzing unbalanced data for models involving fixed effects. Our treatment is necessarily cursory and will not substitute for training available from a sequence of courses in mathematical statistics and linear models. It is intended to introduce the reader to the main issues and to the extensive statistical literature that deals with them.
Article
Some practical techniques are discussed for analyzing time series whose statistical properties are changing with time. We first consider how principal component analysis can reduce the multidimensional nature of certain series and, in particular, apply this technique to the analysis of changing seasonal patterns. Discussions of trend, changes in oscillatory behavior, and "unusual" events follow. The problem of making inferences regarding causation is briefly considered. We conclude with a call for flexibility in approach.
Article
This book provides research workers with the statistical background needed in order to collect and analyze data in an intelligent and critical manner. Key examples and case studies are used to illustrate commonly encountered research problems and to explain how they may be solved or even avoided altogether. Professor Manly also presents a clear understanding of the opportunities and limitations of different research designs, as well as an introduction to some new methods of analysis that are proving increasingly popular. Topics covered include: the differences between observational and experimental studies, the design of sample surveys, multiple regression, interrupted time series, computer intensive statistics, and the ethical considerations of research. In the final chapter, there is a discussion of how the various components of a research study come together.
Article
Our knowledge of the structure and functioning of terrestrial ecosystems on a global scale is not developed to a sufficient degree to understand--much less predict--the consequences of climate change either on the systems themselves or on subsequent atmospheric interactions. In many regards we have lagged behind the atmospheric scientists, and to a certain degree the oceanographers, in establishing a global understanding of the dynamics of our respective systems. This is due in part to the inherently greater complexity of biotic systems, but also to the lack of appropriate tools to measure regional biotic processes. These tools are now becoming available and with them a better understanding of terrestrial and atmospheric interactions. Even as these capabilities become a reality we must be realistic in recognizing that we have so far to go along the road to understanding that useful predictive capacity may elude us for a long time to come. What we need to do is act on the recommendations that have been emerging over the past few years and develop a global program to document more precisely the distribution, structure, and quantity of the earth's biotic systems, their principal functional properties, and--most difficult of all--their changing nature. In order to do this we will have to: (1) perfect some of the emerging new tools for assessing these properties, (2) fill some of the gaps in our knowledge about the relevant processes, and (3) establish an international network of long-term observations and large-scale ecosystem manipulations. We have been aware of these needs and shortcomings for some time and we must move from plans to concerted international action.
Chapter
A conceptual framework for the design, implementation, and operation of scientific information systems has been developed. This framework is based on experience with focused field experiments, long-term data archiving, and data publication. The elements of the framework include management and organizational constraints, the requirements of the scientific community, the flow of data from source to archive, and resource requirements. Examples of these principles, drawn from successful information systems experience with the FIFE Information System and the Pilot Land Data System, are discussed.
Article
Depending upon the level of error inherent in the source data and the error operationally produced through data capture and manipulation, GIS products may possess significant amounts of error. Errors inherent in 1) land-cover maps derived through classification of Landsat digital data; 2) slope-angle and slope-aspect information derived from digital terrain tapes; and 3) soil-type data acquired from USDA Soil Conservation Service soil survey reports, were assessed. These data were compared to field information collected for 35 sample sites. -from Authors
Article
Several approaches are discussed for statistical analysis of large-scale (and possibly unreplicated) ecological experiments. These include intervention analyses and comparisons of alternative models using Bayes' formula. Such techniques are unfamiliar to many ecologists and are not typically included in graduate curricula in ecology. I argue for increased training in these areas and for collaborations between statisticians and ecologists to develop innovative approaches to the analysis of large-scale perturbations.
Article
A prediction method is given for a first- and second-order nonstationary spatio-temporal process. The predictor uses local data only and consists of a two-stage generalized regression estimate of the local drift at the prediction location added to a kriging prediction of the residual process at that location. This predictor is applied to observations on seasonal, rainfall-deposited sulfate over the conterminous United States between summer 1986 and summer 1992. Analyses suggest that predictions and estimated prediction standard errors have negligible to small biases, there is spatially heterogeneous temporal drift, and temporal covariance is negligible.
Article
Functional evaluation of wetlands in nutrient cycling, water quality maintenance, and wetland construction and restoration contexts requires knowledge of differences in microbial processes between different wetland types and understanding of the nature and extent of variation in these processes within a given wetland type. In this study, we measured a suite of microbial variables (microbial biomass C and N content, denitrification enzyme activity, potential net N mineralization and nitrification, and soil respiration) that are indices of wetland nutrient cycling and water quality maintenance functions in four different wetland types (calcareous fens, red maple swamps, woodland pools, and wet clay meadows) in eastern New York state. Total soil C and N content, water content, pH, water-table levels, and groundwater NH+4, NO-3, and electrical conductivity were also measured. The clay meadow wetlands were drier and had lower levels of organic matter and most microbial variables than the other wetland types. Site-to-site variation within the fens was very high and was not strongly controlled by water-table levels. Organic matter content and N status appear to be strong regulators of microbial biomass and activity in fens. Red maple swamps and woodland pools had similar levels of most microbial variables. Variation within these wetland types was controlled by hydrology and organic matter quality. The suite of microbial variables that we measured identified potential functional differences between wetland types and should be useful for comparisons of the water quality maintenance value of different wetlands and for functional evaluation of altered or restored sites.
Article
In this paper, a comprehensive outline of the different types of errors encoutered in the process of data collection is presented. An overview of different errors encountered in the "primary and secondary' methods of data collection is explained. In addition, a brief summary of different standards and specifications used in the primary methods of data collection is provided. Finally, a comparison between the primary and the secondary methods of data collection is made. -from Authors
Article
This paper focuses on the nature of error in spatial databases and the implications of this error for spatial data transformation in GIS applications. It describes an error propagation research paradigm as an information flow linking successively more formal components of error propagation in a GIS context. The paradigm enables researchers to formulate, manipulate, and experiment with components of error propagation to determine their implications for decision making. The applicability of the paradigm is illustrated with a simple GIS application in which error is propagated from sources to final product through a sequence of data transformation functions. -from Authors