Michelle E. Thompson

The importance of defining focal assemblages when evaluating amphibian and reptile responses to land use

Habitat loss and degradation are primary threats to amphibians and reptiles, but the relative effects of common land uses on assemblages and the mechanisms that underlie faunal responses are poorly studied. We reviewed the effects of four prevalent types of habitat alteration (urbanization, agriculture, livestock grazing, and silviculture) on amphibian and reptile species richness and abundance by summarizing reported responses in the literature and by estimating effect sizes across studies for species richness in each land-use type. We then used a multinomial model to classify species as natural habitat specialists, generalists, and disturbed habitat specialists and examined variation in effect sizes for each land-use type according to habitat specialization categories. There were mixed conclusions from individual studies, some reporting negative, neutral, or positive effects of land use on species richness and total abundance. A large proportion of studies reported species-specific effects of individual species abundance. However, in our analysis of effect sizes, we found a general trend of negative effects of land use on species richness. We also demonstrate that habitat associations of common species and species turnover can explain variation in the effect of land use on herpetofauna. Our review highlights the pervasive negative effects of common land uses on amphibians and reptiles, the importance of identifying groups vulnerable to land-use change (e.g., forest-associated species) in conservation studies, and the potential influence of disturbance-associated species on whole assemblage analyses.

Phylogenetic homogenization of amphibian assemblages in human-altered habitats across the globe

Significance Widespread conversion of natural habitats to human land use creates evolutionarily novel environments and causes declines of native species. Stemming biodiversity loss requires an understanding of why some species persist while others decline in these novel habitats. We analyzed survey data of amphibian species from around the globe to determine whether closely related species respond similarly to habitat conversion. We find that species that persist in converted habitats tend to come from the same clades within the amphibian tree of life and that by favoring these widely distributed clades, habitat conversion leads to nonrandom extirpations and loss of evolutionary history. Our results show that the identity of winners and losers during the Anthropocene can be tightly linked to their evolutionary history. Habitat conversion is driving biodiversity loss and restructuring species assemblages across the globe. Responses to habitat conversion vary widely, however, and little is known about the degree to which shared evolutionary history underlies changes in species richness and composition. We analyzed data from 48 studies, comprising 438 species on five continents, to understand how taxonomic and phylogenetic diversity of amphibian assemblages shifts in response to habitat conversion. We found that evolutionary history explains the majority of variation in species’ responses to habitat conversion, with specific clades scattered across the amphibian tree of life being favored by human land uses. Habitat conversion led to an average loss of 139 million years of amphibian evolutionary history within assemblages, high species and lineage turnover at landscape scales, and phylogenetic homogenization at the global scale (despite minimal taxonomic homogenization). Lineage turnover across habitats was greatest in lowland tropical regions where large species pools and stable climates have perhaps given rise to many microclimatically specialized species. Together, our results indicate that strong phylogenetic clustering of species’ responses to habitat conversion mediates nonrandom structuring of local assemblages and loss of global phylogenetic diversity. In an age of rapid global change, identifying clades that are most sensitive to habitat conversion will help prioritize use of limited conservation resources.

Thermal quality influences habitat use of two anole species

Regeneration of secondary forests on previously deforested or degraded land is one of the most dominant forms of land-use change in the tropics. However, the response of animal communities to forest regeneration is poorly understood. To evaluate support for thermal quality as a mechanism driving reptile species distributions during secondary forest succession, we measured operative temperatures and occupancy in three successional forest stages (pasture, secondary forest, and old growth forest) for two anole species common in the landscape (Norops humilis and Norops limifrons). We then measured thermal preference in laboratory experiments and used operative temperature and temperature preference measurements to determine how thermal quality of habitat changes over the course of secondary forest succession, and if occupancy varies as a function of thermal quality. We found that thermal quality was lowest in pasture habitat because of a large frequency of temperatures above the thermal preference range. However, in low thermal quality pasture sites, riparian habitats and remnant trees provided a thermal refuge for both lizard species. Our results support thermal quality as a mechanism for reptile species distributions in altered landscapes and highlight the importance of the maintenance of riparian corridors.

Effects of Secondary Forest Succession on Amphibians and Reptiles: A Review and Meta-analysis

Over the past century, humans have cleared the Earths forests at an alarming rate and intensity. The majority of global forest cover is categorized as secondary forest, and it is becoming increasingly important to consider secondary forests in addition to old-growth forest in conservation planning for biota. We reviewed the literature to synthesize information on amphibian and reptile communities during secondary forest succession. We summarized literature on mechanisms of community change during forest succession and conducted a meta-analysis to estimate effect sizes for species richness and abundance in human-modified landscapes (agriculture, pasture, and plantation) and old-growth forests compared to regenerating secondary forests. Studies reported strong support for differences in species composition among human-modified landscapes, secondary forest, and old-growth forest as well as species-specific responses to successional forest change. Secondary forest generally had higher species richness and abundance than human-modified landscapes, but lower species richness and abundance than old-growth forests. This result was more pronounced in amphibians than reptiles, and effect size of abundance was more variable than richness among studies. Secondary forests have better conservation value than altered habitats, but they do not necessarily hold the same conservation value for species as old-growth forest.

Between the Academy and Queerness: Microaggressions in Social Work Education

Three social work scholars explore their experiences of microaggressions in academia using queer theory as a lens to disrupt, deconstruct, and disorder the dominant heteronormative discourse. Qualitative analysis of autoethnography narratives resulted in seven themes describing experiences of microaggressions in social work education. Themes illuminated were as follows: (1) queer isolation, (2) throwing shade, (3) queer insult, (4) biphobia: not queer (straight) enough, (5) too queer, (6) queer backlash, and (7) revolving closet door. Concept mapping was used to explore each of these areas as they relate to the values of social work. Recommendations for social work education and research are presented.