Ecography最新文献

Despite extensive research, stabilizing mechanisms in ecosystems remain uncertain. Taylor's power law (TPL) is a pervasive ecological pattern that describes how variance scales with mean abundance (σ² = aμᵇ). While TPL has been widely studied within populations, its role across species within communities and its implications for stability remain largely unexplored. A TPL scaling factor (b) < 2 implies an unexplored stabilizing effect of dominant species (hereafter the ‘dominance effect'), where community stability arises from dominant species being relatively more stable than subordinates. This study aims to explore the influence of TPL exponent b on the dominance effect on stability and identify the biotic and abiotic community factors shaping it. Using data from over 9000 permanent vegetation plots globally, we investigated within-community TPL, linked it to the dominance effect, and examined drivers of b values. Results reveal a strong contribution of b, together with species evenness, to dominance effects on stability. A ubiquitous TPL (mode R² = 0.92) with a consistent b < 2 highlights widespread dominance effects. Lower b values were linked to resource-conservative strategies and climatic seasonality, reinforcing the role of environmental filtering in stability. These findings highlight the widespread dominance effect on community temporal stability, particularly driven by woody, large-seeded species in cold, seasonal climates. Moreover, results identify the TPL exponent b as a powerful indicator of dominant species' stabilizing effects, complementing the well-known role of species diversity.

Anthropogenically induced changes in environmental conditions have been affecting species communities globally, leading to shifts in ecosystem functioning. Physical drivers like temperature, salinity and acidification are especially important in coastal ecosystems, and high-resolution time-series are essential to identify how these variables affect zooplankton community composition due to their importance in marine ecosystems. In this study we analysed a zooplankton monitoring dataset spanning from 1996–2021 to identify community changes and their drivers. We examined long-term trends in environmental variables, corresponding total zooplankton biomass as well as changes in the biomass of specific taxa using generalised additive models (GAMs). We found a strong decline in total zooplankton biomass during September and October until 2006 and 2004, respectively. Copepod biomass further decreased during the last decade, while rotifer and cladoceran biomass increased, indicating a dominance shift towards species with shorter generation times and less complex ontogeny. Copepod biomass was negatively correlated with salinity, while cladoceran and rotifer biomass was positively correlated with temperature. Our results highlight that multiple climate change-related environmental variables influence communities in different ways and hence, should be investigated simultaneously. Further, we argue that zooplankton community analyses and monitoring efforts should include small taxa like rotifers.

Island biogeography models primarily rely on island physical features and isolation to explain their biodiversity patterns. While newer models have incorporated functional traits to understand plant distribution, few empirical studies have tried to disentangle geometric constraints from niche-based processes to predict multiple diversity facets of island animals. Frogs are dispersal-limited organisms with narrow physiological requirements, and little is known about how ecological and geomorphological factors dictate their distribution on islands. Here, we tested how climate, productivity, environmental heterogeneity, isolation, and island area influence frog species richness, functional dispersion (FDis), and evolutionary distinctiveness (ED) on islands worldwide using structural equation models. Quantile regression was used to further explore the influence of island size and isolation on diversity facets. We found a positive association of island area and climate (i.e. temperature) with diversity metrics, while isolation had no effect in most of them. Notably, the influence of island area, but not isolation, was more pronounced on highly diverse islands. The relative importance of predictor variables differed between tropical and temperate islands and across facets: geometric constraints were more important for determining species richness and ED in all islands and in tropical islands, while niche-related variables dictated FD in all and both tropical and temperate islands. The low tolerance of frogs for crossing seawater may explain the lack of an isolation effect.

Climate change has widespread effects on the distribution, abundance and behavior of species around the world, leading to the reshuffling of ecological communities. However, it remains unclear whether individual species' range shifts scale up to result in communities whose rate of change lag, lead, or track the rate of climate change. We capitalized on a century-old dataset originally collected by Joseph Grinnell and his students, plus modern resurveys, to measure long-term compositional responses of small mammal communities to climate change in historical and modern eras across three regions in the Sierra Nevada of California (Lassen, Yosemite, Sequoia and Kings Canyon National Parks). Across this period, mean annual temperature in each region increased and mean annual precipitation decreased. We tested whether small mammal communities have shifted their composition in favor of species more adapted to hot and dry conditions, processes known as thermophilization and negative mesophilization, respectively. We found positive thermophilization rates (communities composed of more warm-adapted species) in one of three regions, and negative mesophilization rates (communities composed of dry-adapted species) in one of the three regions. We show that region-specific colonization and extinction dynamics of warm-, cool-, wet- and dry-adapted species jointly drive thermophilization and mesophilization rates, highlighting that community change arises from both species gains and losses. Importantly, thermophilization and mesophilization rates within regions lagged behind corresponding rates of climate change on average by 0.39–1.40°C and 154–301 mm. Our results suggest that the net effects of climate change can be directional at the scale of the ecological community, despite variability in individual species responses to environmental change and the varied mechanisms that govern them. Communities, like many individual species, may already be out of equilibrium with ambient climate.

Simulation outputs from forest landscape models are complex, and tools for their visual analysis and effective communication are often limited. In this paper, we present EcoViz, a novel, open-source visualisation platform designed to complement existing forest models by providing advanced 3D visualisation capabilities. EcoViz facilitates the exploration of simulation results through two primary modes: symbolic rendering, designed for analytical tasks, such as pattern recognition and model evaluation, and photorealistic rendering, leveraging physically based rendering (Mitsuba 3) and a custom library of European 3D tree models for communication purposes. The platform imports spatially explicit individual tree or cohort data and employs a temporally coherent sampling technique to visualise individual trees derived from cell-based density maps. Key features include: interactive side-by-side comparison of different simulation scenarios or time points, with synchronised navigation (viewpoint, timeline, transects), a mini-map overview, timeline controls with linked ecological metric graphs, and transect analysis tools. The practical application of EcoViz is demonstrated by visualising simulations of the Berchtesgaden National Park under baseline and climate change scenarios exported from a forest landscape model. This case study showcases EcoViz's utility for comparative scenario analysis across spatial scales and how it aids model evaluation through visual inspection. While symbolic views support detailed analysis, the photorealistic output offers a compelling tool for science communication with diverse audiences, including scientific peers, forest managers, and the public.