bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/349639

Toads and roads: transport infrastructure severely impacts dispersal regardless of life stage

Cayuela, H.·Bonnaire, E.·Besnard, A.
View original source ↗Export metadata ↓

Abstract

Transport infrastructure such as roads has been reported to negatively affect dispersal. Their effects on dispersal are thought to be complex, depending on the characteristics of the structure and the intensity of the traffic using it. In addition, individual factors, such as age, may strongly affect dispersal decisions and success when individuals are confronted with transport infrastructure. Despite the importance of this topic for wildlife conservation, few studies have investigated the effect of transport infrastructure on individuals dispersal decisions before and after sexual maturity. We examined the effects on two kinds of infrastructure, gravel tracks and paved roads, on the dispersal of an endangered amphibian, the yellow-bellied toad (Bombina variegata). We used capture-recapture data collected during a five-year period on a large, spatially structured population of B. variegata. Our study revealed that emigration rates increased with an individuals age, while dispersal distance decreased. It also showed that both tracks and roads had negative effects on dispersal. The negative effect of roads was stronger than that of tracks. We additionally found that the effect of tracks on dispersal slightly decreased with a toads age. In contrast, the negative effect of roads was severe and relatively similar across age classes.

Source connections

Explore related subjects

ecologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Cayuela, H., Bonnaire, E., Besnard, A.. 2018-06-18. Toads and roads: transport infrastructure severely impacts dispersal regardless of life stage. https://doi.org/10.1101/349639

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Habitat degradation destabilizes complex metacommunities by disrupting dispersal

Habitat loss and fragmentation are rapidly reshaping ecosystems worldwide, yet their consequences for ecological stability remain unresolved. Classical theory, pioneered by Robert May, established rigorous criteria for stability; however, these apply to spatially well-mixed communities, limiting their relevance to habitat degradation. Here, we develop a metacommunity framework that integrates classical stability theory with spatial dynamics to determine how anthropogenic habitat degradation reshapes ecosystem stability. We show that metacommunities exhibit three distinct dynamical regimes following a perturbation (e.g., drought or forest fire): stable regime (perturbations decay and species persist), reactive regime (perturbations are transiently amplified, which increases extinction risk under repeated disturbances), and unstable regime (perturbations grow, causing extinctions even after a single disturbance). Dispersal fundamentally reshapes these stability transitions, converting unstable communities into reactive ones and reactive communities into stable ones. While homogeneous dispersal progressively stabilizes communities, heterogeneous dispersal maximizes stability at intermediate strengths. We further show that habitat loss and fragmentation can be comparably effective at driving species extinctions by shifting metacommunities from stable to reactive and ultimately unstable regimes, demonstrating that fragmentation per se can be as important as habitat loss. Our findings reveal that reactivity is both an early-warning signal of impending instability and a state of elevated extinction risk under recurrent disturbances. By linking stability transitions to changes in population persistence under nonlinear dynamics, our results bridge classical stability theory with spatial ecology and provide a general framework for predicting how ecological complexity and dispersal jointly govern both ecosystem stability and population persistence under habitat degradation.

ecology↗
bioRxiv2026

Joint effects of climate change and urbanization accelerate plant biodiversity loss across urban green spaces

Urbanization and climate change are rapidly reshaping biodiversity worldwide, yet their combined impacts on ecosystems remain poorly understood. Urban green spaces (UGS) underpin urban biodiversity, but differ widely in their structure, management, and exposure to global change. Here, we examine how these two drivers jointly influence plant communities across five major UGS types (allotments, private gardens, residential green spaces, parks, and ruderal areas) in three socio-culturally distinct Swiss cities. By combining vegetation surveys from 180 sites (60 sites per city) with species-specific thermal niches, high-resolution projections of historical and future urban microclimates, and land-use change scenarios, we trace how climate-driven species loss interacts with the shifting availability of urban habitats to shape biodiversity outcomes by mid-century. We found that UGS types differed markedly in their contributions to biodiversity, with allotments and ruderal areas supporting disproportionately high compositional uniqueness. However, climate change alone was projected to drive substantial plant diversity declines across all UGS types, with 40-80% of species exceeding their thermal niches by mid-century based on climate change scenario and UGS type. Although allotments exhibited relatively greater tolerance due to broader community-level thermal preferences, this advantage was undermined by their rapid decline under urbanization. When considered jointly, climate change and urbanization generated widespread biodiversity losses through complementary mechanisms: climate change drove species declines, while urbanization amplified these losses by disproportionately reducing high-value habitats. These results reveal a consistent trajectory of biodiversity decline across urban landscapes and highlight the need to conserve high-diversity yet shrinking UGS, particularly allotments, while enhancing the ecological value and climate resilience of expanding UGS, such as parks and residential areas, to safeguard future urban biodiversity under global change.

ecology↗
bioRxiv2026

Algal turf sediment dynamics across the Florida Reef Tract

Algal turfs and their associated sediments are dominant components of many degraded reefs, where they mediate key ecosystem processes. However, the quantification of algal turfs and their sediments across reef shelves is limited outside Indo-Pacific reef systems. We quantified algal turf length, sediment loads, and sediment grain size distribution across four reef positions (nearshore, inner, middle, and outer) at three locations along the northern Florida Reef Tract (FRT). Sediment loads were positively associated with algal turf length and generally declined moving offshore. Nearshore reefs supported algal turfs that were both 1.6-fold longer and contained 1.6-fold higher sediment loads than on outer reefs, while sediment composition shifted toward finer grain sizes offshore. Nevertheless, regardless of reef position, all algal turfs had high sediment loads ranging from 1,445 to 16,639 g m-2. Our findings suggest that cross-shelf patterns in algal turf sediment dynamics are present on Western Atlantic reefs and reveal that long sediment-laden algal turfs dominate on the FRT. These results highlight the pervasive nature of sediment-laden algal turfs on degraded reefs and emphasize the need to monitor and manage their expansion on reefs subject to chronic coastal development and climate-driven disturbance.

ecology↗