Ecology Letters最新文献

Understanding stability is crucial for predicting ecological responses to environmental fluctuations. While the diversity-stability relationship is well studied, the role of species' fundamental responses remains underexplored. We investigate how the distribution of species' fundamental responses, captured by a novel metric—imbalance—drives community stability through asynchrony and population stability. Using a protist microcosm experiment, we manipulated species richness and response distributions (defined as interspecific variation in species performance curves) under fluctuating temperature at different nutrient concentrations. Results show that lower imbalance leads to higher temporal stability, while richness has no effect. Structural equation modelling revealed that asynchrony and population stability explain 90% of the variation in stability. Imbalance estimated from monocultures predicted community stability, suggesting that fundamental species responses drove community stability. This study offers new insights into the responses of ecological systems to environmental change.

The cover image is based on the article Delicate Trade-Offs: Nonlinear Multiple Biotic Constraints on Absorptive Fine Root Lifespan Across Trees by Zeqing Ma et al., https://doi.org/10.1111/ele70210

As environments worldwide change at unprecedented rates during the Anthropocene, understanding context dependency—how species interactions vary depending on environmental context—is crucial. Combining comparative genomics across 42 angiosperms with transcriptomics, genome-wide association mapping and gene duplication origin analyses, we show for the first time that gene family expansions are important to context-dependent regulation of species interactions. Gene families expanded in mycorrhizal fungi-associating plants display up to 200% more context-dependent gene expression and double the genetic variation associated with mycorrhizal benefits to plant fitness. Moreover, we discover these gene family expansions arise primarily from tandem duplications with > 2-times more tandem duplications genome-wide, indicating gene family expansions continuously supply genetic variation, allowing fine-tuning of context dependency in species interactions throughout plant evolution. Taken together, our results spotlight how widespread gene duplications can provide molecular flexibility required for plant–microbial interactions to match changing environmental conditions.

Alpha (α), beta (𝛽), gamma (𝛾) and zeta (𝛇) diversity metrics are complementary in their information, yet insight from this complementarity has yet to be explored. Here we use postglacial lake sediments for reconstructing plant metacommunity diversity patterns using all four metrics. Based on sedimentary ancient DNA data, we find that the metacommunity both diversified (𝛽_spatial) and homogenised (𝛇) over millennia of ecosystem development, alongside rising taxon richness at both community (α) and metacommunity (𝛾) level. In contrast temporal turnover of taxa (𝛽_temporal) declined, both at the community and metacommunity level. With taxon appearances exceeding disappearances this suggests the co-existence of taxa in the communities increased. However, the shared taxa in the metacommunity (𝛇) showed a continuously high temporal turnover, suggesting the taxa contributing to the metacommunity homogenisation were largely transient. That communities homogenised but remained distinctively different over millennia highlights the importance of individual communities in sustaining metacommunity biodiversity.

The recent announcement of a genetically engineered organism resembling the extinct dire wolf (Aenocyon dirus) has reignited a media and academic debate over the ecological, ethical, and philosophical implications of de-extinction. Although the revival was later clarified to be a modified grey wolf with a small fraction of the dire wolf DNA, the case illustrates how close biotechnology is to achieving a true de-extinction. While proponents promote such techniques as innovative additional tools for conservation, this paper calls for a more critical examination of their broader implications. Drawing on insights from invasion ecology, rewilding, ethics, and governance, we argue that de-extinction must not be guided by feasibility or commercial appeal alone. Instead, it requires a multidisciplinary framework to be thoroughly understood, responsibly guided, and—if deemed appropriate—accepted. As biotechnological innovations advance and may become widely used, they should be aligned with biodiversity conservation principles to avoid unintended ecological consequences.

Sociality offers benefits to species that can enhance their fitness. However, pathogen transmission can be higher in larger groups, potentially negating the advantages of group living. Despite the important paradoxical effects of population density on disease impacts and recovery, the competing effects of density remain unexplored. Here, we examine the response of a social bat species to pathogen invasion by comparing the effect of colony size on disease impacts during the summer (disease-free period) and winter (disease period). During pathogen invasion, larger winter colonies initially experienced relatively higher declines than smaller colonies. Conversely, summer colony size positively influenced colony growth immediately following pathogen invasion and during recovery, suggesting that Allee effects may be important in population resilience. Our results show that hosts faced with a novel pathogen may experience both benefits and costs of group living, and balancing these competing effects could impede evolutionary selection pressure toward asociality.

Following rapid climate change, tundra plant communities are experiencing extensive compositional shifts. A conservation concern is the potential encroachment of boreal species into the tundra (‘borealisation’). Tundra borealisation has been sporadically reported, but not systematically quantified. Here, we synthesised data from across 32 study areas, spanning 1137 plots and 287 vascular plant species, resurveyed between 1981 and 2023. We (i) quantified tundra borealisation as the colonisation and increase in abundance of Boreal and Boreal-Tundra species, (ii) assessed biogeographical, climatic and local borealisation drivers and (iii) identified species contributing to borealisation and their associated traits. Half of the plots experienced borealisation, although borealisation rates were not different to random expectation. Borealisation was greater in Eurasia, closer to the treeline, at higher elevations, in warmer and wetter regions, where climate change was limited, and where initial boreal abundance was lower. Boreal coloniser species were generally short-statured, and more often shrubs and graminoids. Boreal species colonised around three times less frequently than Boreal-Tundra species. Hence, our findings indicate that tundra borealisation is mainly driven by the spread of already established boreal-low Arctic tundra species. These plant community composition changes could have cascading impacts on land-atmosphere interactions, trophic dynamics and Indigenous and local livelihoods.

We investigated the decomposition of diverse root-associated fungi, their influence on native soil carbon (C) dynamics and the relationship of these processes with fungal traits. We quantified the decomposition of ¹³C-labelled mycelium of 14 species, their priming of native soil C, impact on functional soil C pools, microbial use of C and microbial community size and composition and evaluated chemical, morphological and physiological traits of the fungi to investigate their potential to control C processes. Fungal melanin, blackness, C/N and growth rates were linked to necromass decomposability and its stabilisation. Necromass addition commonly caused suppression of native soil C decomposition (negative priming), including that of the resistant C pool, and this suppression was stronger as fungal decomposability decreased. We provide novel, clear evidence of linkages between root-associated fungal traits, necromass decomposition, microbial C use and soil C stability which builds our mechanistic understanding of the role of dead fungi on soil C storage.

Competitive coexistence is often understood as an additive process where coexisting species pairs, triplets, etc. combine to form larger communities. However, emergent coexistence—where multispecies persistence occurs without pairwise coexistence—can arise through mechanisms including intransitive loops, facilitation, or higher-order interactions. Emergent coexistence has functional consequences, for example constraining community assembly and reducing robustness to extinctions. Here, we demonstrate that emergent coexistence can arise without intransitivity in competitive communities with pairwise interactions. First, we develop a simple trade-off model where interactions are competitive, transitive, and pairwise, yet coexistence is emergent. Second, we show that coexistence is typically emergent in well-known hierarchical trade-off models. Third, we find that emergent coexistence frequently occurs without pronounced intransitivity in random model communities. Our results suggest that competitive coexistence may often be emergent, highlighting a need to better understand the mechanisms and prevalence of this phenomenon in order to reliably predict community assembly, robustness, and biodiversity maintenance.