Ecology Letters最新文献

Seasonality can drive the evolution of reproductive plasticity in insects. An extreme form is reproductive diapause, where individuals halt reproduction during unfavourable seasons. How diapause evolves from milder forms of plasticity (e.g., through changes in cue perception and responses) is poorly understood. In the tropics, seasonality is common, but it is unclear how widespread reproductive plasticity is, or how it correlates with dry and wet seasons. Here, we analyse reproductive plasticity in Amazonian butterflies using a four-year monthly time series of reproductive phenotypes. Sampling nine species across four Nymphalidae subfamilies, we observe a widespread occurrence of diverse reproductive plasticity, suggesting repeated evolutionary changes in reproductive plasticity. Detailed analyses of two Catonephele species reveal a conserved cue (temperature), with species-specific divergence of cue response (dry season diapause only in C. acontius). Together, our data support the ubiquity of reproductive plasticity in the tropics and suggest repeated evolutionary change in diapause.

Quantifying biotic interactions at scale is critical to understanding ecosystem functions, such as plant-pollinator interactions. Here, we demonstrate how woody plant functional traits and vegetation structure gathered with remote sensing can aid in predicting plant-pollinator network indices from fine to broad spatial extents. We analysed 209 tropical plant-pollinator networks, where vegetation characteristics were generated using spectral and LiDAR data. We found that pollination network structures were correlated to plant traits reflective of drought-adaptive strategies and nutrient availability. Networks were predicted to be more nested and less specialised with increasing leaf nitrogen content. Further, relationships between leaf thickness, photosynthetic capacity, and water content indicate that networks may be more modular and less connected under arid, high-light conditions where plants invest in water-conserving tissues yet maintain high photosynthetic rates. Our findings reveal plant functional strategies as underlying environmental mechanisms that structure plant-pollinator networks, paving the way to predict interactions using remote sensing.

Genome size is a key genomic trait underpinning evolutionary potential and ecological adaptation in pathogens, yet its biogeographic patterns remain poorly understood. From New Zealand data, we quantify the influence of host traits versus environmental factors on biogeographic patterns of genome size in pathogenic fungi, and test whether these predictors differ between native and alien pathogens. Host plants were the strongest predictors of genome size, with effects particularly pronounced in Basidiomycota and biotrophic fungi. Within co-origin host-pathogen pairs (native-native; alien-alien), conservative host traits were associated with smaller pathogen genomes overall, but with larger genomes in Basidiomycota. Host effects were stronger in native pathogens, while environmental filtering diverged, with climate dominating in native pathogens and terrain-related factors in alien pathogens. Native pathogens exhibited pronounced geographic genomic differentiation, whereas alien pathogens showed spatial homogenization. These results reveal a hierarchical framework that enhances predictions of disease dynamics under global environmental change.

The Thermal Death Time (TDT) model has enabled quantification of heat injury in ectothermic organisms across variable thermal stress intensities and durations. Using experimental data from Drosophila suzukii, here we extend this framework to include a quantitative assessment of repair of thermal injury. We first demonstrate that heat injury accumulates additively and exponentially at stressful temperatures and subsequently show how repair of heat injury also depends on both temperature and duration across permissive temperatures. We find repair to be additive across different permissive temperatures, with the highest repair rate at intermediate temperatures. Importantly, integration of injury and repair rates enables accurate predictions of thermal failure during simple temperature fluctuations alternating between stressful and permissive temperature ranges. Our data therefore support an extension of the TDT framework to integrate injury-repair dynamics. With further validation for other traits and taxa, these dynamics will be critical for assessing thermal vulnerability in a warming climate.

Reciprocal effects between plants and soil have been proposed as mechanisms that promote coexistence. However, recent theoretical and empirical works have questioned their role in stabilizing coexistence within multispecies communities. In these systems, soil-mediated indirect interactions may play a pivotal but often overlooked role. We investigate these indirect interactions using an experimental system of two competing shrub species grown in soil conditioned by a mediating third tree species. Tree-induced shifts in soil microbial communities, metabolites and nutrients boost growth in the weak competitor species while reducing germination in the dominant competitor. Simulations demonstrate that these shifts in plant performance are sufficient to stabilize coexistence, producing simulated spatial distributions consistent with those observed in natural communities. Our findings underscore the role of soil effects in driving indirect interactions that sustain coexistence in diverse plant communities, highlighting the importance of indirect but also positive and negative multitrophic interactions in maintaining biodiversity.

Global environmental change is driving widespread insect declines, yet underlying mechanisms remain poorly understood, particularly when mediated by trophic interactions. Many studies purportedly test global change stressors on insect herbivores mediated via their host plants (bottom-up) and natural enemies (top-down), but we lack a comprehensive understanding of overall effects. Here, we performed a meta-analysis of 246 papers testing 18 distinct global change stressors impacting insect herbivores via trophic interactions. We found variable, often opposing impacts of global change stressors on herbivore fitness when herbivores and their host plants were exposed, while the only detected significant effect involving natural enemies was a reduced herbivore fitness under warming, potentially due to increased enemy attacks. Notably, generalists exhibited greater vulnerability to global change than specialists, challenging assumptions that dietary generalists are more resilient. Insect herbivores tested in agricultural systems were more prone to be benefited by global change, whereas closed experimental systems amplified negative outcomes. Our results underscore the importance of considering trophic interactions and context-specific dynamics in predicting ecological responses to environmental change. By integrating bottom-up and top-down mechanisms, our study provides a nuanced quantitative understanding of how global change influences insect herbivores, with important implications for biodiversity conservation in the Anthropocene.

Plants employ multiple strategies to adapt to their growth environment. Characterizing key dimensions in plant trait space is important for understanding functional diversity within ecosystems. Leaf and root functional traits have been studied in the context of resource economics, but whether they covary, and through which mechanisms, is still debated. We investigated this in subtropical forests by sampling root and leaf traits on individuals of co-existing species in two communities with different resource availability. We found largely non-correlated variation between leaf and fine root traits both across and within communities, and a clear decoupling between leaf economic spectrum and root economic space, independent of evolutionary history. Our results suggest that leaf-root trait relationships are shaped by an interplay between microenvironmental heterogeneity that drives decoupling and shared selection pressures promoting covariation. The interplay explains the weak observed coordination and highlights the importance of environmental context in predicting above- and below-ground plant functions.

Retraction: Z. Tao, K. Zhang, R.M. Callaway, E. Siemann, Y. Liu, and W. Huang, "Native Plant Diversity Generates Microbial Legacies That Either Promote or Suppress Non-Natives, Depending on Drought History," Ecology Letters 27, no. 9 (2024): e14504, https://doi.org/10.1111/ele.14504. The above article, published online on 2 October 2024 in Wiley Online Library (http://onlinelibrary.wiley.com/), has been retracted by agreement between the journal Editor-in-Chief, Peter H. Thrall; and John Wiley & Sons Ltd. Concerns about the data were raised by one of the journal editors. Following publication, the editors identified unusual repetitive patterns in the data underlying the study. The editors concluded that the patterns, identified using common statistical analysis tools, were unlikely to have occurred by chance from a typical environmental data collection effort. When asked about the concerns, the authors shared some raw data but were unable to provide a satisfactory explanation to the editors for the patterns in the published data that the editors could not reconcile with the study's conclusions. When later presented with the possibility of retraction and a draft retraction statement, the authors disagreed strongly and provided a detailed rebuttal of the editors' assessment. They argued in part that the software tools the editors used to identify the duplication patterns had not been peer reviewed or otherwise validated. As part of an extensive investigation of the authors' rebuttal claims, the publisher consulted an anonymous and independent subject matter expert (SME), who confirmed the findings of the editors and noted that the repetitive patterns observed in the underlying data were inconsistent with the reliability required to support the article's conclusions. As a result of the post-publication review by the SME, the editors affirm that they have lost confidence in the results and conclusions. In line with the journal's editorial policies, the editors determined that unresolved concerns regarding data reliability warranted retraction. The authors disagree with the retraction.