Biodiversity Research Institute

Climate change is significantly affecting biodiversity, and organisms that depend on external temperature – such as ectotherms – are particularly vulnerable to these effects. Microhabitats provide refuge for species, thereby reducing exposure to thermal and hydric stress under climate change. Using a mechanistic modelling approach, we assessed how microhabitat variability and physiological traits influence activity behaviour, time spent in preferred temperature, shade selection, and water loss under different climate change scenarios on two green lizard species. We classified study area microhabitats using high‐resolution geospatial data and applied biophysical models to simulate organismal responses under current and future climate change scenarios (+2°C and +4°C). We first calibrated microhabitat‐specific microclimate models using field data and adjusting key parameters that determine surface energy balance and soil heat transfer, including surface roughness height, substrate longwave emissivity, and soil density. We then performed steady‐state ectotherm models and extracted physiological responses such as foraging and basking times, times spent in preferred temperature, selected shade, and water loss under current and projected climate scenarios. Our results revealed differences between species in terms of thermoregulatory and water‐loss dynamics: Timon lepidus showed higher foraging and basking activity, particularly in open rocky microhabitats. In contrast, Lacerta schreiberi relied more on shaded vegetated microhabitats and exhibited higher size‐corrected evaporative water loss. Foraging activity in T. lepidus increased in low‐slope areas, whereas L. schreiberi foraged more in steeper microhabitats, where both species also selected greater shade. Activity increased on south/west slopes, while shade selection was greater on north/west slopes. Activity periods may increase under warming conditions, but this may come at the cost of higher selected shade and water loss. These results go beyond recognizing the buffering role of microhabitats in climate change, by linking fine‐scale thermal and hydric variation to physiological strategies of lizard species. By integrating microclimate and ectotherm models, our work illustrates how species‐specific traits interact with microhabitat heterogeneity to shape differential vulnerability under warming conditions.

ABSTRACTBiodiversity change forecasts rely on long‐term time series, but such data are often scarce in space and time. Here, we interpolated spatiotemporal changes in species richness using a new method based on machine learning that does not require temporal replication at sites. Using 698,692 one‐time sampled vegetation plots, we estimated trends in vascular plant alpha diversity across Europe and validated our approach against 22,852 independent time series. We found an overall near‐zero net change in species richness between 1960 and 2020. However, species richness generally declined from 1960 to 1980 and increased from 2000 to 2020 across habitats. Declines were most pronounced in forests, but trends varied across habitats and regions, with overall increases at higher latitudes and elevations, and declines or stable trends elsewhere. Our findings demonstrate how data without temporal replication can be used to reveal context‐dependent biodiversity dynamics, underscoring their importance for conservation and management.

Debate has arisen on the use of "re-wilding" to promote biodiversity conservation. We contend that approaches aiming for strict non-intervention to restore "wilderness" may be conceptually inconsistent when applied to human-shaped landscapes. Several ecosystems of high biodiversity value, often misclassified as "pristine" have been shaped over millennia of human use, a context rarely acknowledged by re-wilding approaches. Rural abandonment in Europe is seen as an opportunity to promote biodiversity conservation through "re-wilding", but management neglect may favor forest species at the expense of open-habitat species. In Mediterranean regions, where cultural ecosystems have high conservation value, management neglect may reduce biodiversity and increase wildfire hazard, especially under climate change. Using three Mediterranean basin case studies, we argue that wilderness-focused re-wilding, if applied uncritically, can have unintended negative consequences. While recognizing the diversity of re-wilding concepts, we highlight the need for context-specific strategies, where active management remains essential.

ABSTRACTBiological invasion is a key driver of biodiversity loss, leading to significant changes in community composition and structure. Hence, understanding how biological invasions influence community assembly processes is crucial for identifying invasion mechanisms and developing management strategies aimed at minimizing their impacts on natural ecosystems. Beyond environmental filtering or niche‐based exclusion, biotic interactions (e.g., interspecific competition) between invasive and their native counterparts can also affect species distributions and local invasion dynamics. This study combined joint Species Distribution Models (jSDMs) with a long‐term European‐level dataset to uncover co‐occurrence patterns and community organization of freshwater macroinvertebrates in the context of biological invasion. To do this, we considered functional traits, phylogenetic relationships, environmental niches, and residual variance potentially mirroring species‐to‐species interactions between non‐native and native species. Environmental covariates exhibited significant differences in explaining variation of occurrences between native and non‐native species; although environmental filtering had a more pronounced effect on native species. This finding supported the hypothesis that non‐native species generally exhibit broader environmental niches. Indeed, our findings emphasized the importance of biotic filtering (in the form of interspecific competition and invasion meltdown among non‐native species) acting beyond the abiotic environment in shaping the distribution of non‐native and native species, providing a more nuanced view of the key drivers underlying invasion risk and success.

The common loon (Gavia immer) is considered a sentinel of ecosystem health, and declines in this species have been linked to several different drivers. Loons are widely recognized as being very sensitive to fungal respiratory disease, and this has proven a major barrier to successful clinical care and rehabilitation. The goal of the present study was to assess the presence of antibody reactivity to Aspergillus with secondary testing including Aspergillus antigen and gliotoxin detection as well as plasma protein electrophoresis and complete blood count as sample volume permitted. Conducted over two years in collaboration with multiple centers in Maine, New Hampshire, and Florida, samples were collected in the Northeast from healthy wild adult and juvenile birds (n = 72) as well as clinically abnormal birds presented for rehabilitation (n = 29). In addition, a cohort of rehabilitation samples was obtained from clinically abnormal overwintering birds (n = 6). Necropsy results were available for those found moribund or euthanized (n = 29). Of these birds, eight were confirmed to have aspergillosis where the remainder were diagnosed with other complications. Only three of eight displayed antibody reactivity to Aspergillus using a recombinant antigen-based ELISA and four tested positive for the presence of gliotoxin. An abnormal electrophoretogram was present in samples from all eight birds. The presence of antibody reactivity was not observed in clinically normal loons and only in one of the necropsied loons without aspergillosis. Overall, aspergillosis appears uncommon in healthy, free-ranging birds but likely can be an opportunistic infection after a stress inducing event. Serological testing and protein electrophoresis may provide an opportunity to monitor the health of this species and may improve the ability to manage this species in captivity.

ABSTRACTChanges in vegetation cover are occurring across sub‐Saharan Africa and can have substantial effects on ecological communities, but limited data make understanding status and trends difficult for many taxa. We surveyed birds for several decades across Uganda using point counts. Using time‐to‐detection analysis in a trait‐informed Bayesian multi‐species occupancy framework, we model bird species richness as a function of year and local tree cover across 28 sites. We test for trends in richness and occupancy, and for the relationship between these and local and landscape‐scale tree cover. Species richness increased at 75% of sites through the study period, and generalist bird species were most likely to be increasing in occupancy. Forest specialist bird species, and to a lesser extent generalists, responded positively to tree cover. Woody cover is changing across Uganda, with declines most pronounced in areas with the highest tree cover. This is likely to be causing declines in forest specialist species while favouring generalists. When tree cover decline is caused by conversion to croplands, rather than transitions to grasslands, grassland specialists are unlikely to benefit. Effects of climate and land use change and population pressure are likely to continue to alter woody plant cover and thus affect East African bird communities.