@article{leidner_haddad_2011, title={Combining Measures of Dispersal to Identify Conservation Strategies in Fragmented Landscapes}, volume={25}, ISSN={["0888-8892"]}, DOI={10.1111/j.1523-1739.2011.01720.x}, abstractNote={Abstract:  Understanding the way in which habitat fragmentation disrupts animal dispersal is key to identifying effective and efficient conservation strategies. To differentiate the potential effectiveness of 2 frequently used strategies for increasing the connectivity of populations in fragmented landscapes—corridors and stepping stones—we combined 3 complimentary methods: behavioral studies at habitat edges, mark‐recapture, and genetic analyses. Each of these methods addresses different steps in the dispersal process that a single intensive study could not address. We applied the 3 methods to the case study of Atrytonopsis new species 1, a rare butterfly endemic to a partially urbanized stretch of barrier islands in North Carolina (U.S.A.). Results of behavioral analyses showed the butterfly flew into urban and forested areas, but not over open beach; mark‐recapture showed that the butterfly dispersed successfully through short stretches of urban areas (<500 m); and genetic studies showed that longer stretches of forest (>5 km) were a dispersal barrier, but shorter stretches of urban areas (≤5 km) were not. Although results from all 3 methods indicated natural features in the landscape, not urbanization, were barriers to dispersal, when we combined the results we could determine where barriers might arise: forests restricted dispersal for the butterfly only when there were long stretches with no habitat. Therefore, urban areas have the potential to become a dispersal barrier if their extent increases, a finding that may have gone unnoticed if we had used a single approach. Protection of stepping stones should be sufficient to maintain connectivity for Atrytonopsis new species 1 at current levels of urbanization. Our research highlights how the use of complementary approaches for studying animal dispersal in fragmented landscapes can help identify conservation strategies.}, number={5}, journal={CONSERVATION BIOLOGY}, author={Leidner, Allison K. and Haddad, Nick M.}, year={2011}, month={Oct}, pages={1022–1031} }
 @article{leidner_haddad_lovejoy_2010, title={Does Tropical Forest Fragmentation Increase Long-Term Variability of Butterfly Communities?}, volume={5}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0009534}, abstractNote={Habitat fragmentation is a major driver of biodiversity loss. Yet, the overall effects of fragmentation on biodiversity may be obscured by differences in responses among species. These opposing responses to fragmentation may be manifest in higher variability in species richness and abundance (termed hyperdynamism), and in predictable changes in community composition. We tested whether forest fragmentation causes long-term hyperdynamism in butterfly communities, a taxon that naturally displays large variations in species richness and community composition. Using a dataset from an experimentally fragmented landscape in the central Amazon that spanned 11 years, we evaluated the effect of fragmentation on changes in species richness and community composition through time. Overall, adjusted species richness (adjusted for survey duration) did not differ between fragmented forest and intact forest. However, spatial and temporal variation of adjusted species richness was significantly higher in fragmented forests relative to intact forest. This variation was associated with changes in butterfly community composition, specifically lower proportions of understory shade species and higher proportions of edge species in fragmented forest. Analysis of rarefied species richness, estimated using indices of butterfly abundance, showed no differences between fragmented and intact forest plots in spatial or temporal variation. These results do not contradict the results from adjusted species richness, but rather suggest that higher variability in butterfly adjusted species richness may be explained by changes in butterfly abundance. Combined, these results indicate that butterfly communities in fragmented tropical forests are more variable than in intact forest, and that the natural variability of butterflies was not a buffer against the effects of fragmentation on community dynamics.}, number={3}, journal={PLOS ONE}, author={Leidner, Allison K. and Haddad, Nick M. and Lovejoy, Thomas E.}, year={2010}, month={Mar} }
 @article{leidner_haddad_2010, title={Natural, not urban, barriers define population structure for a coastal endemic butterfly}, volume={11}, ISSN={["1572-9737"]}, DOI={10.1007/s10592-010-0117-5}, number={6}, journal={CONSERVATION GENETICS}, author={Leidner, Allison K. and Haddad, Nick M.}, year={2010}, month={Dec}, pages={2311–2320} }
 @article{leidner_pouyat_2009, title={Jumping into the policy puddle}, volume={7}, number={10}, journal={Frontiers in Ecology and the Environment}, author={Leidner, A. and Pouyat, R. V.}, year={2009}, pages={555–556} }
 @article{hess_bartel_leidner_rosenfeld_rubino_snider_ricketts_2006, title={Effectiveness of biodiversity indicators varies with extent, grain, and region}, volume={132}, ISSN={["1873-2917"]}, DOI={10.1016/j.biocon.2006.04.037}, abstractNote={Abstract The use of indicator taxa for conservation planning is common, despite inconsistent evidence regarding their effectiveness. These inconsistencies may be the result of differences among species and taxonomic groups studied, geographic location, or scale of analysis. The scale of analysis can be defined by grain and extent, which are often confounded. Grain is the size of each observational unit and extent is the size of the entire study area. Using species occurrence records compiled by NatureServe from survey data, range maps, and expert opinion, we examined correlations in species richness between each of seven taxa (amphibians, birds, butterflies, freshwater fish, mammals, freshwater mussels, and reptiles) and total richness of the remaining six taxa at varying grains and extents in two regions of the US (Mid-Atlantic and Pacific Northwest). We examined four different spatial units of interest: hexagon (∼649 km 2 ), subecoregion (3800–34,000 km 2 ), ecoregion (8300–79,000 km 2 ), and geographic region (315,000–426,000 km 2 ). We analyzed the correlations with varying extent of analysis (grain held constant at the hexagon) and varying grain (extent held constant at the region). The strength of correlation among taxa was context dependent, varying widely with grain, extent, region, and taxon. This suggests that (1) taxon, grain, extent, and study location explain, in part, inconsistent results of previous studies; (2) planning based on indicator relationships developed at other grains or extents should be undertaken cautiously; and (3) planning based on indicator relationships developed in other geographic locations is risky, even if planning occurs at an equivalent grain and extent.}, number={4}, journal={BIOLOGICAL CONSERVATION}, publisher={Elsevier BV}, author={Hess, George R. and Bartel, Rebecca A. and Leidner, Allison K. and Rosenfeld, Kristen M. and Rubino, Matthew J. and Snider, Sunny B. and Ricketts, Taylor H.}, year={2006}, month={Oct}, pages={448–457} }