Biology subjects

Waldock, C.

Publications and source records attributed to Waldock, C..

8 recordsLinked to original sources

bioRxiv2026

Anthropogenic-driven loss of an adaptive radiation reduces thermal response diversity

Biodiversity is predicted to stabilize ecosystems if species have different environmental responses. How this response diversity is shaped by ecological and evolutionary processes remains poorly understood. We determine the drivers of thermal response diversity of 16 Swiss peri-alpine lake-fish communities. We report the first evidence that evolutionary diversification of lineages through adaptive radiation can increase the response diversity of an ecosystem. In-situ diversification increases response diversity in the cold-deep lake environment, but non-endemic and non-native species contributed only weakly to response diversity. The loss of endemic species during historical anthropogenic eutrophication led to a negative legacy on present thermal response diversity in cold and deep lake strata. Overall, the interplay of evolutionary diversification, ecological assembly and anthropogenic impacts drives variation in response diversity. Conserving and restoring processes that generate diversity may help maintain ecosystem stability beyond the Anthropocene.

ecology↗

bioRxiv2026

Unexpected global biodiversity responses to climate change arise from complex adaptation, seascape, and dispersal dynamics

Global marine biodiversity peaks in the tropics and is widely projected to shift polewards under climate warming as species track thermal optima. These projections rely largely on phenomenological models that treat species responses as shifts in climate suitability and neglect fundamental eco-evolutionary dynamics. The consequences of these dynamics in fluctuating populations for global biodiversity patterns therefore remain unresolved. We addressed this deficit by integrating local adaptation, dispersal, and gene flow - mediated trait homogenisation into spatially explicit global simulations of >1,400 tropical reef fishes under climate change. Biodiversity responses departed systematically from simple poleward redistribution. Depending on the interaction between dispersal and adaptive capacity, latitudinal richness peaks widened or narrowed, shifted equatorward or poleward, or collapsed entirely. These alternative regimes emerged from threshold-dependent interactions between seascape connectivity, metapopulation trait homogenisation, and accumulating thermal stress. Critically, greater dispersal enhanced persistence only below seascape-driven connectivity thresholds; beyond which homogenisation of traits across thermally heterogeneous populations disrupted local adaptation - particularly at metapopulation peripheries - and increased extinction risk. Continuous demographic feedback further generated cumulative stress and extinction tipping dynamics absent from snapshot suitability models. Our results show that eco-evolutionary dynamics can invert or destabilise expected climate-driven redistribution patterns, indicating that projections excluding these mechanisms may systematically misestimate the magnitude and direction of global biodiversity change in a rapidly warming ocean.

ecology↗

bioRxiv2025

Systemic bio-inequity links poverty to biodiversity and induces a conservation paradox

O_LIBiodiversity is declining globally while inequity is growing, and poverty rates are not improving. Global sustainable development and conservation initiatives aim to address biodiversity loss and poverty simultaneously. C_LIO_LIThrough text analysis of global biodiversity policies, we identified a consistent narrative that countries with high biodiversity are expected to use this natural capital to reduce poverty. Theoretically then, should higher biodiversity lead to higher prosperity? Clearly countries with higher biodiversity often experience higher poverty rates, so we explore how this paradox emerges using a path analysis integrating multiple mediating factors represented in biological, historical, and socio-economic data. C_LIO_LIWe find that historical colonial exploitation was directed towards biodiversity rich regions, and through socio-economic legacies, continues to influence present-day poverty. At a country-scale, biodiversity is associated with higher poverty rates through increasing the likelihood of historical colonisation. Colonisation drove colonised countries towards natural resource exportation with weakened governance and increased poverty rates. We find no statistical support that country-scale biodiversity levels directly influence poverty, either positively or negatively. C_LIO_LIMoreover, we find that conservation investments did not align with countries biodiversity or their economic capacity to protect nature, indicating a conservation paradox. Our work uncovers that conservation initiatives to protect biodiversity ignore that biodiversity is strongly associated as a historical catalyst for modern global inequalities. C_LIO_LIOur findings quantitatively support the "systemic bio-inequity" hypothesis proposed here. This hypothesis argues that modern biodiversity-poverty linkages are, at least partly, attributed to historical legacies of unequal exploitation of the natural resources provided by biodiversity. This hypothesis aligns with the theory of ecologically unequal exchange. Our findings highlight the problematics of the narrative that natural wealth, and its conservation, will underpin future economic prosperity of countries. This assumption overlooks systemic, historical and institutional drivers of modern poverty. C_LIO_LIRecognizing that colonial and neoliberal structures have created inverted poverty-biodiversity relationships fundamentally changes how we should approach conservation. A decolonial approach is needed in conservation to address this legacy, whereby conservationists must not only recognise but challenge and replace damaging narratives that overlook past and present inequalities in access to the benefits of biodiversity. C_LI

ecology↗

bioRxiv2021

How many replicates to accurately estimate fish biodiversity using environmental DNA on coral reefs?

Quantifying the diversity of species in rich tropical marine environments remains challenging. Environmental DNA (eDNA) metabarcoding is a promising tool to face this challenge through the filtering, amplification, and sequencing of DNA traces from water samples. However, the reliability of biodiversity detection from eDNA samples can be low in marine environments because eDNA density is low and certainly patchy in this vast, heterogenous and dynamic environment. So, the number of sampling replicates and filtered volume necessary to obtain accurate estimates of biodiversity in rich tropical marine environments using eDNA metabarcoding is still unknown. Here, we used a paired sampling design of 30L per replicate on 68 reef transects from 8 sites in three tropical regions and identified fish Molecular Taxonomic Units (MOTUs) using a 12S marker. We quantified local biodiversity variation as MOTU richness, compositional turnover and compositional nestedness between replicated pairs of seawater samples. We report strong turnover of MOTUs between replicated pairs of samples undertaken in the same location, time, and conditions. Paired samples contained non-overlapping assemblages rather than subsets of one-another. As a result, localised diversity accumulation curves showed that even 6 replicates (180L) in the same location underestimated local diversity (for an area <1km). However, sampling of regional diversity using [~]25 replicates in variable locations (often covering 10s of km) achieved saturation of biodiversity accumulation curves. Our results demonstrate high variability of diversity estimates perhaps arising from heterogeneous and local distribution of eDNA distribution in seawater or highly skewed frequencies of eDNA traces. This high compositional variability has consequences for using eDNA to monitor temporal and spatial biodiversity changes of local assemblages. Future biomonitoring efforts could be strongly undermined by a high level of false-negative detections under low replication protocols. We reveal the need to increase replicates or increase sampled water volume to better inform management of marine biodiversity using eDNA.

ecology↗

bioRxiv2021

A quantitative review of abundance-based species distribution models

The contributions of species to ecosystem functions or services depend not only on their presence in a given community, but also on their local abundance. Progress in predictive spatial modelling has largely focused on species occurrence, rather than abundance. As such, limited guidance exists on the most reliable methods to explain and predict spatial variation in abundance. We analysed the performance of 68 abundance-based species distribution models fitted to 800,000 standardised abundance records for more than 800 terrestrial bird and reef fish species. We found high heterogeneity in performance of abundance-based models. While many models performed poorly, a subset of models consistently reconstructed range-wide abundance patterns. The best predictions were obtained using random forests for frequently encountered and abundant species, and for predictions within the same environmental domain as model calibration. Extending predictions of species abundance outside of the environmental conditions used in model training generated poor predictions. Thus, interpolation of abundances between observations can help improve understanding of spatial abundance patterns, but extrapolated predictions of abundance, e.g. under climate change, have a much greater uncertainty. Our synthesis provides a roadmap for modelling abundance patterns, a key property of species distributions that underpins theoretical and applied questions in ecology and conservation.

ecology↗

bioRxiv2019

Temperature-related biodiversity change across temperate marine and terrestrial systems

Climate change is reshaping global biodiversity as species respond to changing temperatures. However, the net effects of climate-driven species redistribution on local assemblage diversity remain unknown. Here, we relate trends in species richness and abundance from 21,500 terrestrial and marine assemblage time series across temperate regions (23.5-60.0{degrees}) to changes in air or sea surface temperature. We find a strong coupling between biodiversity and temperature changes in the marine realm, which is conditional on the baseline climate. We detect increases in species richness with increasing temperature that is twice as pronounced in warmer locations, while abundance declines with warming in the warmest marine locations. In contrast, we did not detect systematic temperature-related richness or abundance trends on land, despite a greater magnitude of warming. We also found no evidence for an interaction between biodiversity change and latitude, further emphasizing the importance of baseline climate in structuring assemblages. As the world is committed to further warming, significant challenges remain in maintaining local biodiversity amongst the non-uniform inflow and outflow of "climate migrants" across distinct regions, especially in the ocean.

ecology↗

bioRxiv2018

Biodiversity trends are stronger in marine than terrestrial assemblages

Human activities have fundamentally altered biodiversity. Extinction rates are elevated and model projections suggest drastic biodiversity declines. Yet, observed temporal trends in recent decades are highly variable, despite consistent change in species composition. Here, we uncover clear spatial patterns within this variation. We estimated trends in the richness and composition of assemblages in over 50,000 time-series, to provide the most comprehensive assessment of temporal change in biodiversity across the planet to date. The strongest, most consistent pattern shows compositional change dominated by species turnover, with marine taxa experiencing up to fourfold the variation in rates of change of terrestrial taxa. Richness change ranged from no change to richness gains or losses of ~10% per year, with tropical marine biomes experiencing the most extreme changes. Earth is undergoing a process of spatial reorganisation of species and, while few areas are unaffected, biodiversity change is consistently strongest in the oceans.

ecology↗

bioRxiv2018

The geography of the Anthropocene differs between the land and the sea

O_LIClimate change and other anthropogenic drivers of biodiversity change are unequally distributed across the world. The geographic patterns of different drivers, and the spatial overlap among these drivers, have important implications for the direction and pace of biodiversity change, yet are not well documented. Moreover, it is unknown if the geographic patterns of drivers differ between the terrestrial and marine realm, as expected due to marked differences in how humans interact with the land and ocean. C_LIO_LIWe compiled global gridded datasets on climate change, land-use, resource exploitation, pollution, species invasions, and human population density. We used multivariate statistics to examine the spatial relationships among the datasets and to characterize the typical combinations of drivers experienced by different parts of the world. C_LIO_LIWe found stronger positive correlations among drivers in the terrestrial than in the marine realm, leading to areas of high intensities of multiple drivers on land. Climate change tended to be negatively correlated with other drivers in the terrestrial realm (e.g., in the tundra and boreal forest with high climate change but low human use and pollution) whereas the opposite was true in the marine realm (e.g., in the Indo-Pacific with high climate change and high fishing). C_LIO_LIWe show that different regions of the world can be defined by anthropogenic threat complexes (ATCs), distinguished by different sets of drivers with varying intensities. The ATCs can be used to test hypothesis about the pattern of biodiversity change, especially the joint effects of multiple drivers. More generally, our global analysis highlights the broad conservation priorities needed to mitigate the effects of anthropogenic change on biodiversity responses, with different priorities emerging on land and in the ocean, and in different parts of the world. C_LI

ecology↗