Ecology Letters最新文献

Lalechère, E., Marrec, R., & Lenoir, J. (2025). A Non-Equilibrium Species Distribution Model Reveals Unprecedented Depth of Time Lag Responses to Past Environmental Change Trajectories. Ecology Letters, 28(1), e70040. https://doi.org/10.1111/ele.70040

In the ‘Material and Methods’ section and in the ‘Results’ section, the assertation that the distribution of the residual errors followed a normal distribution was unnecessary to assess model validity. This may lead to some confusion about the family of distribution that was used. As stated in the article, we relied on the binomial distribution.

We apologize for this mistake.

The scientific aspiration of building causal knowledge has received little explicit discussion in ecology despite its fundamental importance. When methods are described as ‘causal’, emphasis is increasingly placed on statistical techniques for isolating associations so as to quantify causal effects. In contrast, natural scientists have historically approached the pursuit of causal knowledge through the investigation of mechanisms that interconnect the components of systems. In this paper, we first summarise a recently published multievidence paradigm for causal studies meant to reconcile conflicting viewpoints. We then describe some of the basic principles of causal statistics and the challenge of estimating pure causal effects. We follow that by describing basic principles related to causal mechanistic investigations, which focus on characterising the structures and processes conveying causal effects. While causal statistics focuses on estimating effect sizes, mechanistic investigations focus on characterising the attributes of the underlying structures and processes linking causative agents to responses. There are important differences between how one approaches each endeavour, as well as differences in what is obtained from each type of investigation. Finally, the case is made that an explicit assessment of existing mechanistic knowledge should be an initial step in causal investigations.

Freshwater ecosystems worldwide are under pressure from neonicotinoid insecticides. While it is recognised that communities of species are responsible for ecosystem functioning, it remains unknown if neonicotinoid-induced community transformations negatively affect ecosystem functioning. Therefore, we employed an experimental approach with 36 naturally established freshwater ecosystems exposed to increasing field-realistic concentrations of the neonicotinoid thiacloprid. Upon exposure, we found severe degradation of ecosystem functioning in the form of loss of organic matter consumption and dramatic shifts in primary productivity. This functional decline coincides with strongly eroded species co-occurrence networks to the point that these are indistinguishable from randomised assemblages of species. Together, these findings show how current environmental concentrations of a neonicotinoid can strongly disrupt freshwater ecosystem functioning via degradation of the invertebrate food web. Since this dramatic ecosystem degradation occurs below nearly all identified ecotoxicological risks, we call here for the reconsideration of the use of these insecticides.

Spillback—where non-native species increase native pathogen prevalence—is potentially an important mechanism by which non-natives contribute to zoonotic disease emergence. However, spillback has not yet been directly demonstrated because it is difficult to disentangle from confounding factors which correlate with non-native species abundance and native pathogen prevalence. Here, we capitalise on replicated, quasi-experimental releases of non-native pheasants (Phasianus colchicus) to compare vector abundance and native pathogen prevalence between sites with similar local conditions but different non-native densities. Prevalence of Borrelia spp. (the causative agent of Lyme disease) in questing ticks was almost 2.5x higher in woods where pheasants are released compared to control woods, with a particularly strong effect on Borrelia garinii, a bird specialist genospecies. Furthermore, adult (but not nymphal) ticks tended to be more abundant at pheasant-release woods. This work provides evidence that non-native species can impact zoonotic pathogen prevalence via spillback in ecologically relevant contexts.

Responding to Mori (2025), we discuss that the simplifications and implications of the Tea Bag Index are essential to its ease of use. However, they necessitate careful attention, especially regarding the appropriate incubation time. Aligning with Mori (2025), we call for a deeper understanding of the interpretation of k_TBI.

Botelho et al. claimed that ecosystem models cannot make accurate population forecasts and should not be used in conservation management. We agree that producing accurate forecasts from ecosystem models is difficult, but assert that it has been achieved and their utility as a decision-support tool is evident.

A much remarked-upon pattern in nature is elevated trait disparity in sympatric relative to allopatric populations or species. Early explanations focused on secondary contact between allopatrically speciating taxa and emphasised adaptive divergence driven by costly interactions in sympatry (i.e., ‘character displacement’). Here we consider a related hypothesis, ‘species sorting’, which describes a bias in the outcome of secondary contact wherein lineages are unlikely to establish sympatry unless and until they evolve sufficient trait differences in allopatry. Sorting-like processes are prevalent in community assembly theory but are more seldom discussed in the context of speciation and secondary sympatry. We first define ecological and reproductive species sorting as analogous to ecological and reproductive character displacement, and we synthesise ‘differential fusion’ and the ‘Templeton effect’ within this framework. Through the logic of coexistence and assembly theories, we distinguish the types of allopatry-derived trait differences that will likely promote sympatry from those that likely will not, and we discuss biogeographic consequences of the latter. We then highlight new empirical approaches to distinguish sorting from displacement and survey the mixed evidence to-date. We finally suggest key priorities for future research into the hypothesized role of species sorting as a generator of major biodiversity patterns.

Taxonomic diversity effects on forest productivity and response to climate extremes range from positive to negative, suggesting a key role for complex interactions among neighbouring trees. To elucidate how neutral interactions, hierarchical competition and resource partitioning between neighbours' shape tree growth and climate response in a highly diverse Amazonian forest, we combined 30 years of tree censuses with measurements of water- and carbon-related traits. We modelled individual tree growth response to climate and neighbourhood to disentangle the relative effect of neighbourhood densities, trait hierarchies and dissimilarities. While neighbourhood densities consistently decreased growth, trait dissimilarity increased it, and both had the potential to influence climate response. Greater water conservatism provided a competitive advantage to focal trees in normal years, but water–spender neighbours reduced this effect in dry years. By underlining the importance of density and trait-mediated neighbourhood interactions, our study offers a way towards improving predictions of forest dynamics.