Ecology Letters

Zhang, Entao; Wang, Yang; Chen, Shiping; Zhou, Daowei; Shangguan, Zhouping; Huang, Jianhui; He, Jin‐Sheng; Wang, Yanfen; Sheng, Jiandong; Tang, Lisong; Li, Xinrong; Dong, Ming; Wu, Yan; Hu, Shuijin; Bai, Yongfei

doi: 10.1111/ele.14516pmid: 39354912

The intricate mechanisms controlling plant diversity and community composition are cornerstone of ecological understanding. Yet, the role of mycorrhizal symbiosis in influencing community composition has often been underestimated. Here, we use extensive species survey data from 1315 grassland sites in China to elucidate the influence of mycorrhizal symbiosis on plant phylogenetic diversity and community assembly. We show that increasing mycorrhizal symbiotic potential leads to greater phylogenetic dispersion within plant communities. Mycorrhizal species predominantly influence deterministic processes, suggesting a role in niche‐based community assembly. Conversely, non‐mycorrhizal species exert a stronger influence on stochastic processes, highlighting the importance of random events in shaping community structure. These results underscore the crucial but often hidden role of mycorrhizal symbiosis in driving plant community diversity and assembly. This study provides valuable insights into the mechanisms shaping ecological communities and the way for more informed conservation that acknowledges the complex interplay between symbiosis and community dynamics.

dos Santos, Danilo F. B.; Herschberger, Jacob E.; Subedi, Bijay; Pocius, Victoria M.; Neely, Wesley J.; Greenspan, Sasha E.; Becker, C. Guilherme; Romero, Gustavo Q.; Kersch‐Becker, Mônica F.

doi: 10.1111/ele.14499pmid: 39354894

Shelter‐building insects are important ecosystem engineers, playing critical roles in structuring arthropod communities. Nonetheless, the influence of leaf shelters and arthropods on plant–associated microbiota remains largely unexplored. Arthropods that visit or inhabit plants can contribute to the leaf microbial community, resulting in significant changes in plant–microbe interactions. By artificially constructing leaf shelters, we provide evidence that shelter‐building insects influence not only the arthropod community structure but also impact the phyllosphere microbiota. Leaf shelters exhibited higher abundance and richness of arthropods, changing the associated arthropod community composition. These shelters also altered the composition and community structure of phyllosphere microbiota, promoting greater richness and diversity of bacteria at the phyllosphere. In leaf shelters, microbial diversity positively correlated with the richness and diversity of herbivores. These findings demonstrate the critical role of leaf shelters in structuring both arthropod and microbial communities through altered microhabitats and species interactions.

Winkler, Lennart; Freckleton, Robert P.; Székely, Tamás; Janicke, Tim

doi: 10.1111/ele.14515pmid: 39354897

Size differences between males and females are common across the tree of life (termed sexual size dimorphism; SSD), and have fundamental implications for ecology, life history and behaviour of both sexes. Conventionally, SSD is thought to evolve in response to sex‐specific sexual selection but more recent work suggests that ecological processes can also promote sex‐differences in size. Here, we provide a global test for the role of sexual selection in the evolution of sexual size dimorphism using data from 77 comparative studies spanning the major classes of the animal kingdom. We show that intense sexual selection typically correlates with male‐biased SSD across species. Importantly, pre‐copulatory but not post‐copulatory sexual selection predicts SSD, suggesting a pervasive role of premating male–male competition and female choice to drive sex differences in body size. Collectively, our findings suggest that pre‐copulatory sexual selection plays a major role in the evolution of male‐biased SSD.

Stocker, Clayton W.; Bamford, Stephanie M.; Jahn, Miki; Mazué, Geoffrey P. F.; Pettersen, Amanda K.; Ritchie, Daniel; Rubin, Alexander M.; Noble, Daniel W. A.; Seebacher, Frank

doi: 10.1111/ele.14511pmid: 39354891

Climate change is altering temperature means and variation, and both need to be considered in predictions underpinning conservation. However, there is no consensus in the literature regarding the effects of temperature fluctuations on biological functions. Fluctuations may affect biological responses because of inequalities from non‐linear responses, endocrine regulation or exposure to damaging temperatures. Here we establish the current state of knowledge of how temperature fluctuations impact biological responses within individuals and populations compared to constant temperatures with the same mean. We conducted a meta‐analysis of 143 studies on ectothermic animals (1492 effect sizes, 118 species). In this study, 89% of effect sizes were derived from diel cycles, but there were no significant differences between diel cycles and shorter (<8 h) or longer (>48 h) cycles in their effect on biological responses. We show that temperature fluctuations have little effect overall on trait mean and variance. Nonetheless, temperature fluctuations can be stressful: fluctuations increased ‘gene expression’ in aquatic animals, which was driven mainly by increased hsp70. Fluctuating temperatures also decreased longevity, and increased amplitudes had negative effects on population responses in aquatic organisms. We conclude that mean temperatures and extreme events such as heat waves are important to consider, but regular (particularly diel) temperature fluctuations are less so.

Jackson, Toby D.; Bittencourt, Paulo; Poffley, Jakob; Anderson, Juliet; Muller‐Landau, Helene C.; Ramos, Pablo A. R.; Rowland, Lucy; Coomes, David

doi: 10.1111/ele.14527pmid: 39354905

In tropical forests, trees strategically balance growth patterns to optimise fitness amid multiple environmental stressors. Wind poses the primary risk to a tree's mechanical stability, prompting developments such as thicker trunks to withstand the bending forces. Therefore, a trade‐off in resource allocation exists between diameter growth and vertical growth to compete for light. We explore this trade‐off by measuring the relative wind mortality risk for 95 trees in a tropical forest in Panama and testing how it varies with tree size, species and wind exposure. Surprisingly, local wind exposure and tree size had minimal impact on wind mortality risk; instead, species wood density emerged as the crucial factor. Low wood density species exhibited a significantly greater wind mortality risk, suggesting a prioritisation of competition for light over biomechanical stability. Our study highlights the pivotal role of wind safety in shaping the life‐history strategy of trees and structuring diverse tropical forests.

Eduardo, Leandro Nolé; Mincarone, Michael Maia; Sutton, Tracey; Bertrand, Arnaud

doi: 10.1111/ele.14510pmid: 39354890

Deep‐pelagic fishes are among the most abundant vertebrates on Earth. They play a critical role in sequestering carbon, providing prey for harvestable fishing stocks and linking oceanic layers and trophic levels. However, knowledge of these fishes is scarce and fragmented, hampering the ability of both the scientific community and stakeholders to address them effectively. While modelling approaches incorporating these organisms have advanced, they often oversimplify their functional and ecological diversity, potentially leading to misconceptions. To address these gaps, this synthesis examines the biodiversity and ecology of global deep‐pelagic fishes. We review pelagic ecosystem classifications and propose a new semantic framework for deep‐pelagic fishes. We evaluate different sampling methods, detailing their strengths, limitations and complementarities. We provide an assessment of the world's deep‐pelagic fishes comprising 1554 species, highlighting major groups and discussing regional variability. By describing their morphological, behavioural and ecological diversity, we show that these organisms are far from homogeneous. Building on this, we call for a more realistic approach to the ecology of deep‐pelagic fishes transitioning between very different ecological niches during diel vertical migrations. To facilitate this, we introduce the concept of ‘diel‐modulated realised niche’ and propose a conceptual model synthesising the multiple drivers responsible for such transitions.

Li, Jingyi; Brose, Ulrich; Rosenbaum, Benjamin; Ryser, Remo; Berti, Emilio

doi: 10.1111/ele.14522pmid: 39354907

Information transmission among species is a fundamental aspect of natural ecosystems that faces significant disruption from rapidly growing anthropogenic sensory pollution. Understanding the constraints of information flow on species' trophic interactions is often overlooked due to a limited comprehension of the mechanisms of information transmission and the absence of adequate analytical tools. To fill this gap, we developed a sensory information‐constrained functional response (IFR) framework, which accounts for the information transmission between predator and prey. Through empirical evaluation, the IFR provided a biologically grounded explanation for the systematic variation of functional responses. Specifically, it posits that the variation of different functional‐response shapes, associated with community stability, is attributable to limitations in sensory information transmission among species. This not only deepens our mechanistic understanding of species interactions but also elucidates how anthropogenic activities are reshaping species interactions and community dynamics by disrupting information exchange through sensory pollution.

Hu, Guorui; Bai, Haonan; Zhao, Yunpeng; Chen, Ning; Li, Honglin; Mao, He; Guo, Zengpeng; Sheng, Xiongjie; Zhang, Hui; An, Hang; Zhang, Panhong; Zhang, Zhengkuan; Sun, Yinguang; Ma, Miaojun

LaManna, Joseph A.; Hartig, Florian; Myers, Jonathan A.; Freckleton, Robert P.; Detto, Matteo; Surendra, Akshay; Doolittle, Cole J.; Bachelot, Bénédicte; Bagchi, Robert; Comita, Liza S.; DeFilippis, David M.; Huanca‐Nunez, Nohemi; Hülsmann, Lisa; Jevon, Fiona V.;

Byers, James E.; Pringle, James M.

doi: 10.1111/ele.14520pmid: 39354906

For marine species with planktonic dispersal, invasion of open ocean coastlines is impaired by the physical adversity of ocean currents moving larvae downstream and offshore. The extent species are affected by physical adversity depends on interactions of the currents with larval life history traits such as planktonic duration, depth and seasonality. Ecologists have struggled to understand how these traits expose species to adverse ocean currents and affect their ability to persist when introduced to novel habitat. We use a high‐resolution global ocean model to isolate the role of ocean currents on the persistence of a larval‐producing species introduced to every open coastline of the world. We find physical adversity to invasion varies globally by several orders of magnitude. Larval duration is the most influential life history trait because increased duration prolongs species' exposure to ocean currents. Furthermore, variation of physical adversity with life history elucidates how trade‐offs between dispersal traits vary globally.