Papers by Diana Stralberg
Ecology and Evolution
Climate change refugia are areas that are relatively buffered from contemporary climate change an... more Climate change refugia are areas that are relatively buffered from contemporary climate change and may be important safe havens for wildlife and plants under anthropogenic climate change. Topographic variation is an important driver of thermal heterogeneity, but it is limited in relatively flat landscapes, such as the boreal plain and prairie regions of western Canada. Topographic variation within this region is mostly restricted to river valleys and hill systems, and their effects on local climates are not well documented. We sought to quantify thermal heterogeneity as a function of topography and vegetation cover within major valleys and hill systems across the boreal–grassland transition zone.Using iButton data loggers, we monitored local temperature at four hills and 12 river valley systems that comprised a wide range of habitats and ecosystems in Alberta, Canada (N = 240), between 2014 and 2020. We then modeled monthly temperature by season as a function of topography and diffe...
Frontiers in Ecology and Evolution, 2021
Distributions of landbirds in Canadian northern forests are expected to be affected by climate ch... more Distributions of landbirds in Canadian northern forests are expected to be affected by climate change, but it remains unclear which pathways are responsible for projected climate effects. Determining whether climate change acts indirectly through changing fire regimes and/or vegetation dynamics, or directly through changes in climatic suitability may allow land managers to address negative trajectories via forest management. We used SpaDES, a novel toolkit built in R that facilitates the implementation of simulation models from different areas of knowledge to develop a simulation experiment for a study area comprising 50 million ha in the Northwest Territories, Canada. Our factorial experiment was designed to contrast climate effects pathways on 64 landbird species using climate-sensitive and non-climate sensitive models for tree growth and mortality, wildfire, and landbirds. Climate-change effects were predicted to increase suitable habitat for 73% of species, resulting in average ...
Frontiers in Ecology and the Environment, 2020
PLoS ONE, 2014
Tidal marshes maintain elevation relative to sea level through accumulation of mineral and organi... more Tidal marshes maintain elevation relative to sea level through accumulation of mineral and organic matter, yet this dynamic accumulation feedback mechanism has not been modeled widely in the context of accelerated sea-level rise. Uncertainties exist about tidal marsh resiliency to accelerated sea-level rise, reduced sediment supply, reduced plant productivity under increased inundation, and limited upland habitat for marsh migration. We examined marsh resiliency under these uncertainties using the Marsh Equilibrium Model, a mechanistic, elevation-based soil cohort model, using a rich data set of plant productivity and physical properties from sites across the estuarine salinity gradient. Four tidal marshes were chosen along this gradient: two islands and two with adjacent uplands. Varying century sea-level rise (52, 100, 165, 180 cm) and suspended sediment concentrations (100%, 50%, and 25% of current concentrations), we simulated marsh accretion across vegetated elevations for 100 years, applying the results to high spatial resolution digital elevation models to quantify potential changes in marsh distributions. At low rates of sea-level rise and mid-high sediment concentrations, all marshes maintained vegetated elevations indicative of mid/high marsh habitat. With century sea-level rise at 100 and 165 cm, marshes shifted to low marsh elevations; mid/high marsh elevations were found only in former uplands. At the highest century sea-level rise and lowest sediment concentrations, the island marshes became dominated by mudflat elevations. Under the same sediment concentrations, low salinity brackish marshes containing highly productive vegetation had slower elevation loss compared to more saline sites with lower productivity. A similar trend was documented when comparing against a marsh accretion model that did not model vegetation feedbacks. Elevation predictions using the Marsh Equilibrium Model highlight the importance of including vegetation responses to sea-level rise. These results also emphasize the importance of adjacent uplands for long-term marsh survival and incorporating such areas in conservation planning efforts.
Biodiversity and Conservation, Nov 17, 2010
Conservation of migratory shorebirds and waterfowl presents unique challenges due to extensive hi... more Conservation of migratory shorebirds and waterfowl presents unique challenges due to extensive historic loss of wetland habitats, and current reliance on managed landscapes for wintering and migratory passage. We developed a spatially-explicit approach to estimate potential shorebird and waterfowl densities in California by integrating mapped habitat layers and statewide bird survey data with expert-based habitat rankings. Using these density estimates
Quantifying the relative contributions of environmental conditions and spatial factors to species... more Quantifying the relative contributions of environmental conditions and spatial factors to species distribution can help improve our understanding of the processes that drive diversity patterns. In this study, based on tree inventory, topography and soil data from a 20-ha stem-mapped permanent forest plot in Guangdong Province, China, we evaluated the influence of different ecological processes at different spatial scales using canonical redundancy analysis (RDA) at the community level and multiple linear regression at the species level. At the community level, the proportion of explained variation in species distribution increased with grid-cell sizes, primarily due to a monotonic increase in the explanatory power of environmental variables. At the species level, neither environmental nor spatial factors were important determinants of overstory species ’ distributions at small cell sizes. However, purely spatial variables explained most of the variation in the distributions of under...
Environmental Research Letters
The spatially varying influence of humans on fire probability in North America Marc-André Parisie... more The spatially varying influence of humans on fire probability in North America Marc-André Parisien, Carol Miller, Sean A Parks et al.-Different regional climatic drivers of Holocene large wildfires in boreal forests of northeastern America Cécile C Remy, Christelle Hély, Olivier Blarquez et al.-Recent citations Reforestation policy has constrained options for managing risks on public forests Victor J. Lieffers et al-Wildland fire risk research in Canada Lynn M. Johnston et al-Focus on changing fire regimes: interactions with climate, ecosystems, and society Brendan M Rogers et al
Electronic supplementary material The online version of this article (doi:10.1007/s13157-010-0052... more Electronic supplementary material The online version of this article (doi:10.1007/s13157-010-0052-8) contains supplementary material, which is available to authorized users.
The Condor, 2020
Estimating the population abundance of landbirds is a challenging task complicated by the amount,... more Estimating the population abundance of landbirds is a challenging task complicated by the amount, type, and quality of available data. Avian conservationists have relied on population estimates from Partners in Flight (PIF), which primarily uses roadside data from the North American Breeding Bird Survey (BBS). However, the BBS was not designed to estimate population sizes. Therefore, we set out to compare the PIF approach with spatially explicit models incorporating roadside and off-road point-count surveys. We calculated population estimates for 81 landbird species in Bird Conservation Region 6 in Alberta, Canada, using land cover and climate as predictors. We also developed a framework to evaluate how the differences between the detection distance, time-of-day, roadside count, and habitat representation adjustments explain discrepancies between the 2 estimators. We showed that the key assumptions of the PIF population estimator were commonly violated in this region, and that the 2...
More than 80 percent of San Francisco Bay's original tidal wetlands have been altered or disp... more More than 80 percent of San Francisco Bay's original tidal wetlands have been altered or displaced, reducing available habitat for a range of tidal marsh-dependent species, including the Federally listed California Clapper Rail (Rallus longirostris obsoletus) and three endemic Song Sparrow (Melospiza melodia) subspecies. In the South Bay, many tidal marshes were converted to commercial salt ponds, which have since become among the most important Pacific coast sites for shorebirds, waterfowl and other waterbirds. Recently, however, over 6,000 ha of commercial salt ponds were sold to wildlife management agencies for creation and restoration of tidal marsh systems, which will result in a significant change in the Bay's wetland landscape. This situation creates a need to evaluate the interrelated and potentially conflicting habitat needs of a wide range of species, in order to inform priorities for wetland restoration and management. Using a combination of standardized bird surv...
This study examines the effect of rural residential development and landscape composition on bree... more This study examines the effect of rural residential development and landscape composition on breeding birds in Placer County’s foothill oak woodlands. Point count survey data were used to construct generalized linear models for individual species’ abundance or probability of occurrence, based on two sets of variables: GIS-derived landscape characteristics, including development density, oak woodland proportion, and habitat diversity; and field-collected local habitat parameters. We found that many species examined were sensitive to either development density or landscape composition at some distance between 250 and 4,000 m. Of the 48 breeding species common enough to analyze statistically, the occurrence of 24 species was significantly associated with landscape characteristics. Species shown to be associated with development density and/or urban edge proximity included the lark sparrow (-), Rufouscrowned sparrow (-), western meadowlark (-), black Phoebe (+), house finch (+) and west...
Conservation Letters
Global and national commitments to slow biodiversity loss by expanding protected area networks al... more Global and national commitments to slow biodiversity loss by expanding protected area networks also provide opportunities to evaluate conservation priorities in the face of climate change. Using recently developed indicators of climatic macrorefugia, environmental diversity, and corridors, we conducted a systematic, climate-informed prioritization of conservation values across North America. We explicitly considered complementarity of multiple conservation objectives, capturing key niche-based temperature and moisture thresholds for 324 tree species and 268 songbird species. Conservation rankings were influenced most strongly by climate corridors and speciesspecific refugia layers. Although areas of high conservation value under climate change were partially aligned with existing protected areas, ∼80% of areas within the top quintile of biome-level conservation values lack formal protection. Results from this study and application of our approach elsewhere can help improve the long-term value of conservation investments at multiple spatial scales.
Diversity
Populations of Canada Warbler (Cardellina canadensis) are declining in Canada’s Atlantic Northern... more Populations of Canada Warbler (Cardellina canadensis) are declining in Canada’s Atlantic Northern Forest. Land conservancies and government agencies are interested in identifying areas to protect populations, while some timber companies wish to manage forests to minimize impacts on Canada Warbler and potentially create future habitat. We developed seven conservation planning scenarios using Zonation software to prioritize candidate areas for permanent land conservation (4 scenarios) or responsible forest management (minimizing species removal during forest harvesting while promoting colonization of regenerated forest; 3 scenarios). Factors used to prioritize areas included Canada Warbler population density, connectivity to protected areas, future climate suitability, anthropogenic disturbance, and recent Canada Warbler observations. We analyzed each scenario for three estimates of natal dispersal distance (5, 10, and 50 km). We found that scenarios assuming large dispersal distances...
Avian Conservation and Ecology
Canada's boreal forest region is among the most extensive and largely intact ecosystems on earth,... more Canada's boreal forest region is among the most extensive and largely intact ecosystems on earth, but has experienced rapid industrial development in the last half-century. Calls for urgent conservation action have been prompted by the increasing pace of development and declines in biodiversity, including songbirds. To assist conservation decision making, we introduce a framework to facilitate selection of the highest priority areas for a given conservation objective. We varied six key decision points representing possible constraints or a priori conservation factors: (1) prioritization metric (species representation vs. diversity), (2) geographic stratification, (3) degree of anthropogenic disturbance, (4) species' conservation status, (5) species' ecological association, and (6) climate-change and uncertainty discounting. Using the Zonation conservation planning tool, we evaluated landbird conservation priorities across 128 scenarios for 63 passerine species based on current and projected future density predictions. We compared Zonation land rankings across scenarios with respect to consistency, efficiency (additive and proportional conservation value per unit area), and the relative contributions of each of the six factors of interest. We found large differences between solutions depending on constraints and conservation objectives, and relatively low conservation efficiency overall, with the largest gains in overall conservation value observed in areas ranging from 0.31-0.56 of the study region. This reflects the large range of conservation opportunities still present in the Canadian boreal region, and the widely dispersed nature of landbird distributions, which results in high substitutability among similar areas. However, we did find increasing consistency among solutions as multiple constraints were considered. In particular, stratifying solutions geographically resulted in more consistent priorities, although at the expense of efficiency. Other constraints, including climate change, disturbance-and uncertainty-discounting, and the selection and weighting of species, helped to further focus priorities. Although no single scenario can be viewed as prescriptive, we provide a roadmap for prioritizing boreal songbird conservation efforts across multiple conservation objectives. Stratégies visant l'identification d'endroits prioritaires pour la conservation de passereaux en forêt boréale canadienne
Ecography, 2016
Many of the Neotropical migrant bird species that breed throughout the Canadian boreal region are... more Many of the Neotropical migrant bird species that breed throughout the Canadian boreal region are not found in the Alaskan boreal region, separated by the northwestern cordilleran mountains, despite the presence of climatically suitable habitat. We asked whether biological or climatic factors constrain certain species from crossing this geographic barrier. Analyzing a comprehensive dataset for 80 boreal passerine species, we used phylogenetic logistic regression to evaluate the relative importance of physical, migratory and competition metrics versus current and paleoclimatic suitability factors. Controlling for current climatic suitability within boreal Alaska, we found that species with the greatest climatic suitability across the northwestern cordillera, presently and also during the mid-Holocene period, were most likely to be regular breeders in the Alaskan boreal region. Migratory strategy also played a role, but could not be disentangled from its strong phylogenetic basis. Our analysis suggests that the perceived barrier of the northwestern cordillera may be easily weakened as climate change improves conditions there for many forest species. The weakening of this barrier may lead to relatively rapid range expansions and the reshuffling of species communities. Species' realized distributional shifts will be a function of the interplay between a changing climate and static topographic features.
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Papers by Diana Stralberg