Biological Reviews最新文献

Coexistence is simultaneously one of the most fundamental concepts of ecology, and one of the most difficult to define. A particular challenge is that, despite a well-developed body of research, several different schools of thought have developed over the past century, leading to multiple independent, and largely isolated, branches of literature with distinct methodologies. Here, we provide a broad overview of the most common concepts and metrics currently used to detect and characterise ecological coexistence. We first introduce four classes of behaviour, which jointly describe the ways in which community dynamics can unfold: (i) the existence of a feasible steady state (or invariant set), i.e. where all coexisting species retain positive abundances in the long-term in the absence of interference by external forces; (ii) the existence of a local attractor that draws the community towards a feasible steady state from within a restricted set of starting conditions; (iii) the existence of a global attractor that draws the community towards feasible steady states from any non-zero starting condition; and (o) a null transient state, where species abundances vary over time irrespective of steady states and attractors. Next, we explain how these classes of behaviour relate to commonly used metrics for identifying and characterising coexistence, including analyses of parameter sensitivity, asymptotic return rates, invasion growth rates, and time to extinction. We then discuss the scope and limitations of each of these behavioural classes and corresponding metrics, with a particular focus on applications in empirical systems. Finally, we provide a potential workflow for matching empirical questions to theoretical tools, and present a brief prospectus looking forward to opportunities for advancing and integrating research on coexistence.

Fire is a major form of environmental disturbance, and in recent years, due to anthropogenic climate change and anthropogenic land management, we are seeing increases in the frequency and intensity of fires. With bees being an important, diverse group of pollinators that is facing declines globally, understanding how they respond to fires is critical. Here, we conduct a literature review to understand what is known from the literature on how bees respond to fire, and how such responses to fire can vary depending on species life-history traits and aspects of fire regimes. Our literature review yielded 148 studies from 140 publications. Bee responses to fire were extremely variable, with no consistent pattern in abundance or species richness increasing, decreasing, or showing no significant change under fire. Different families and taxa responded differently and to different aspects of fire regimes. Generally, regarding taxonomic vulnerability, andrenids and colletids were vulnerable to fire, whereas halictids responded favourably to fire. In terms of guild, ground-nesting generalists responded favourably to fire, whereas cavity-nesting specialists were most vulnerable to fire. We revealed major gaps in research in the Southern Hemisphere and in tropical landscapes dominated by flowering trees, with most studies conducted in pine-forested, fire-prone landscapes in the Northern Hemisphere. Additionally, only a few studies used manipulative experiments, or have considered how to maximise bee recovery after fires. Overall, fire is an important disturbance affecting bee communities, and while some species may benefit from certain fire regimes, other species are vulnerable, and management to preserve such species under predictions of increasingly frequent and severe fires is required.

Over a century of research has revealed an amazing complexity of behaviours and physiological adaptations that allow tiny bark beetles to overcome large trees, sometimes resulting in outbreaks that kill millions of trees. Turning a tree into a home and successfully raising offspring involves constant interactions among the beetles, the tree, its microbiome, and the beetles' associated microbes, all influenced by abiotic factors that can determine success or failure. While we have learned much about these systems, substantial knowledge gaps remain. This synthesis aims to clarify and integrate current understanding, identify gaps, challenge long-held assumptions, and address interpretative issues that impede progress toward a holistic understanding of these systems. We advocate for expanding perspectives using synecological approaches to understand these complex systems better. We encourage expanding research into how colonization by the bark beetle–fungi complex influences subsequent tree decay and forest carbon dynamics. An explicit goal is to provide a comprehensive resource for new researchers while encouraging them to question established hypotheses and to explore new avenues of enquiry.

Humans play key roles in shaping the structure and processes of ecosystems globally, especially in cities. This recognition has prompted a recent focus on understanding urban systems via interactions between human social systems and ecological and evolutionary processes. Most research has focused on interactions between two of these three domains. Here we present a framework for linking all three – social, ecological, and evolutionary – by focusing on phenotypic response and effect traits, illustrating the framework's utility in understanding wildlife dynamics in urban systems. We first present a generalized model for the social–ecological–evolutionary–phenotypic (SEEP) framework, then use urban climate as a specific example, provide guidance on how to implement this approach, and finally discuss emerging questions motivated by the framework and challenges in utilizing the approach.

Metazoan multicellularity and eusociality — both outcomes of the fraternal major transitions — have numerous features in common such as uneven distribution of group-establishing potential. In addition to this framework, I argue herein that the group-forming principles of metazoan multicellularity and eusociality are analogous to hierarchical cancer in that the cancer stem cells generate other cancer cells deprived of tumorigenicity. As such, I introduce concepts of germinating reproducers and sterile workers widely applicable to those systems. In particular, exploitative replication is suggested as an efficient strategy for maintaining the cooperation of fraternal cooperative organisations accompanied by asymmetric replication/reproduction. From this point of view, the defectors that spontaneously appear in metazoan multicellular organisms, eusocial colonies, and cancer clusters are cancers, egg-laying workers, and hypertumours, respectively. In a way similar to the policing observed in eusociality and metazoan multicellularity, I propose the hypothesis that the lactate-producing Warburg effect of cancer cells could represent a policing mechanism against hypertumours. Specifically, the Warburg effect establishes an acidified microenvironment that can repress growth of defector hypertumours by restricting diffusion of cancer growth factors. Considering the altruistic nature of the Warburg effect and metabolic plasticity, the possibility of hypertumours performing oxidative phosphorylation is discussed. This structural analogy not only highlights the role of asymmetric replication/reproduction in highly cooperative systems, but also provides a novel perspective on the social interactions of cancer cells, potentially laying foundations for clinical strategies aimed at disrupting cancer cooperation.

The browning of freshwater ecosystems is increasingly evident in temperate and northern regions, with widespread ramifications for lake physics, chemistry, and biology. Contrasting results on how freshwater browning may impact fish have been reported, but there has been no comprehensive examination of how browning may cause cascading effects on individual- to population- to community-level traits of freshwater fishes. We addressed this knowledge gap by summarizing the existing literature and conducting a series of original analyses to: (i) explore the effects of a brown water gradient on populations of eight economically important species of fish across 871 lakes; and (ii) examine how a brown water gradient may influence community trait compositions across 303 lakes. From our literature synthesis, we found that fish growth is often negatively associated with browner waters, despite browning generally showing no effect on fish foraging. We also demonstrated that browner waters had greater abundances of northern pike (Esox lucius) and walleye (Sander vitreus), but lower numbers of lake trout (Salvelinus namaycush), yellow perch (Perca flavescens), largemouth bass (Micropterus salmoides), smallmouth bass (M. dolomieu), and lake whitefish (Coregonus clupeaformis). Moreover, we showed that fish communities were significantly more likely to contain species with larger eyes in browner lakes. Lastly, we examined relationships between various metrics of browning (i.e. dissolved organic carbon, Secchi transparency, water colour) and present a framework for how the effects of freshwater browning on fish may scale from individuals to populations to communities.

Globally, rivers receive a diverse range of chemicals, including metals, pesticides, persistent organic pollutants, petrochemicals, human and veterinary pharmaceuticals and personal care products. However, the extent to which these different chemical groups affect riverine invertebrate communities is not well defined. Here we set out to evaluate the available evidence for associations between British riverine invertebrate communities and different chemical groups (and individual members of these chemical groups). Our assessment comprised three elements, (i) an evaluation of whether environmental concentrations of these chemicals exceed the lowest effect concentrations (ECs) based on laboratory tests, (ii) an assessment of associations between chemical groups and changes in British riverine invertebrate communities using the existing published literature, and (iii) calculated potential risk of toxicity of the chemical groups to invertebrates based on measured exposures (Environmental Agency monitoring data) and laboratory-based measurements of the lethal concentration required to kill half of the tested population (LC₅₀). Our conclusions indicate that metal and pesticide pollutants (including the veterinary medicine fipronil) are of greatest concern for British riverine invertebrate communities. Petrochemicals were also of potential concern, however, risk calculations indicate this risk is lower than that for metals and pesticides. All other chemical groups assessed appeared to be of relatively low risk to British riverine invertebrates based on the available information. However, the concentrations of some pharmaceuticals and personal care products in British rivers exceeded the lowest ECs for some invertebrate species and require further investigation. Given the widespread concern regarding declines in freshwater invertebrates, studies on chemical impacts on invertebrate populations in British rivers are surprisingly limited and further targeted studies are warranted.