Invasive species pose the greatest threat to biodiversity, having a significant impact on the native biota and ecosystems. With the added challenge of climate change, it remains uncertain how these invasive mammals will spread globally in the future. Using species distribution modelling, we assessed the potential distribution of 64 invasive mammals and identified hotspots of invasion. Our findings indicate that European countries are particularly vulnerable to mammal invasions. Our analysis of niche dynamics also suggests that 37 out of 64 invasive mammals are experiencing niche shifts, which could portend future invasions.
Functional and phylogenetic diversity of plant communities can influence the diversity of herbivorous insects and, consequently, the structure of plant-herbivore interactions. However, few studies have evaluated how functional and phylogenetic diversity affect the structure of ecological networks, especially in savanna ecosystems. We investigated whether the functional and phylogenetic diversity of plant communities influenced the topology of plant-herbivore networks in Neotropical savannas. Our study was performed in 12 remnant areas of neotropical savannas in Brazil. We tested the hypothesis that higher functional and phylogenetic diversity in plant communities increases the species richness and abundance of herbivorous insects. Plant communities with higher functional and phylogenetic diversity should be expected to exhibit more specialized and modular plant-herbivore networks. Here, we sampled 255 insect species, 73 plant species, and identified 218 distinct plant-herbivore interactions. Plant functional diversity reduced the richness and abundance of herbivorous insects, and leaf thickness was the only plant trait associated with increased herbivore richness and abundance. Furthermore, we found that phylogenetic diversity increased the insect species richness, supporting our hypotheses. However, contrary to our expectations, our results show that neither the functional nor the phylogenetic diversity of plant communities affected the topological descriptors of plant-herbivore networks. This study suggests that, while plant functional and phylogenetic diversity shapes the diversity of herbivore communities, its impact on network structure may be mediated by additional ecological or environmental factors, such as habitat structure, resource availability, and microclimatic variation.
Forecasting ecosystems under climate change requires multi-species approaches that account for ecological interactions through ecological networks. While previous projections have used network approaches mainly focusing on extinction-cascade directionality as a driver of ecological change, few multi-species projections have considered the resilience mechanisms of ecological networks to species extinctions. These mechanisms are link-loss sensitivity (the inverse of a network’s ability to withstand loss of links when interaction partners go extinct) and realisation of rewiring potential (the capacity to reallocate lost interactions to novel or existing partners). Using a new quantitative framework, we simulate compositional and network changes across globally distributed, in-situ sampled mutualistic frugivory networks. These simulations are based on species-specific climate-driven extinction cascades that incorporate both resilience mechanisms simultaneously. To assess the impact of network resilience mechanisms on biodiversity loss and network connectedness, we introduce and explore two-dimensional resilience landscapes defined by link-loss sensitivity and rewiring potential. We evaluate outcomes under optimistic and pessimistic resilience assumptions, and both low- and high-emission climate change scenarios to improve understanding of the potential consequences of extinction cascades across the Earth. Additionally, we compare climate driven projections with baseline scenarios that remove the least- and most-connected species in each network. In contrast to traditional models emphasizing bottom-up or top-down cascades, we account for bi-directional extinction processes to better reflect ecological reality. Our findings suggest that ignoring ecological network resilience mechanisms may significantly underestimate ecological change, particularly in terms of biodiversity loss and shifts in network connectedness under climate change.
Understanding how species traits shape ecological interactions across organizational levels is fundamental to explaining tropical biodiversity. In plant-pollinator systems, competition, niche partitioning, and specialist-generalist strategies are closely linked to functional trait variation, which can influence species coexistence and network structure. Yet, how the functional diversity of interacting groups determines network organization remains poorly understood, particularly in pristine tropical forests. Here, we examined how plant and bee functional diversity structures plant-pollinator interaction networks in a pristine Amazonian forest. Specifically, we evaluated whether functional richness, evenness, and dispersion of plants and bees influence interaction diversity, interaction evenness, network specialization, and connectance, and whether species traits predict species-level specialization. Higher bee functional richness was associated with lower network specialization, suggesting that a broader range of pollinator traits promotes more generalized interaction patterns. In contrast, greater plant functional dispersion and higher bee functional evenness were associated with reduced connectance, indicating that trait differentiation among plants may promote niche partitioning, whereas an even distribution of pollinator functional traits may redistribute interactions among functionally similar species. Solitary bees showed higher specialization than social bees, highlighting their potential importance for the reproduction of plant species with specific pollination requirements. Overall, our findings show that functional trait diversity shapes plant-pollinator network organization at both community and species levels. By integrating functional traits into interaction network analyses, this study advances understanding of the mechanisms supporting niche partitioning, functional redundancy, network robustness, and ecosystem functioning in highly diverse tropical forests.
This paper presents an evolutionary game-theoretic model to explore the transition of human economies between non-symbiotic and symbiotic regimes, driven by the level of renewable natural resource availability. Drawing analogies to biological ecosystems, we formalize a threshold-driven function that triggers regime shifts when resource stocks dip below a critical limit. Through replicator dynamics grounded in the Price equation, our results show that, in a non-symbiotic regime, populations move from competitive to predatory behaviors, overshooting the planet’s regenerative capacity. Conversely, a symbiotic regime promotes cooperation and resource-sharing, thus reducing the risk of ecological collapse. Simulations indicate that, under the normalized ecological-footprint indicator used in the model, a predator-dominated world would demand renewable-resource services equivalent to approximately 2.30 times the system’s regenerative capacity. In contrast, a mutualist-dominated scenario reduces this demand to approximately 0.99 times regenerative capacity, conditional on lower depletion intensity and greater responsiveness to resource scarcity. The findings highlight how strategic choices shape ecological footprints, offering pathways for policy interventions to encourage collective solutions and minimize exploitation pressures.
