Ecological Monographs最新文献

{"title":"Comparing the differing effects of host species richness on metrics of disease","authors":"Michael H. Cortez","doi":"10.1002/ecm.1626","DOIUrl":"10.1002/ecm.1626","url":null,"abstract":"<p>Changes in host species richness can alter infection risk and disease levels in multi-host communities. I review theoretical predictions for direct and environmental transmission pathogens about the effects of host additions (or removals) on three commonly used disease metrics: the pathogen community reproduction number <span></span><math>\u0000 <mrow>\u0000 <mfenced>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mn>0</mn>\u0000 </msub>\u0000 </mfenced>\u0000 </mrow></math> and infection prevalence and infected density in a focal host. To extend this prior work and explain why predictions differ between metrics, I analyze Susceptible Infected-Recovered-type models of an environmentally transmitted pathogen and multiple host species that compete for resources. Using local sensitivity analysis, I show how trait-mediated and density-mediated indirect effects drive each metric's response to variation in an added host's ability to transmit a pathogen, the added host's density, and the pathogen transmission mechanism. For each disease metric, the responses are typically predicted by the added host's ability to transmit the pathogen when interspecific competition is weak whereas the responses can be altered by shifts in host densities when interspecific competition is strong. In addition, the three metrics often respond in the same direction. However, the metrics can respond in different directions for three reasons: (1) differences between the ability of exposed individuals to transmit the pathogen over the length of time the individuals are infected (i.e., host competence) and a host population's instantaneous net rate of production of infectious propagules; (2) strong density-mediated feedbacks driven by disease-induced mortality; and (3) host additions or removals cause large changes in focal host density via competition or disease-induced mortality. This study extends and unifies prior theoretical studies, and helps identify the rules governing the context-dependent relationships between host species richness and the three metrics of disease.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142374526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mycorrhizal fungi as critical biotic filters for tree seedling establishment during species range expansions","authors":"Jordon C. Tourville,&nbsp;Thomas R. Horton,&nbsp;Martin Dovciak","doi":"10.1002/ecm.1634","DOIUrl":"10.1002/ecm.1634","url":null,"abstract":"<p>Global warming has been shifting climatic envelopes of many tree species to higher latitudes and elevations across the globe; however, unsuitable soil biota may inhibit tree migrations into these areas of suitable climate. Specifically, the role of mycorrhizal fungi in facilitating tree seedling establishment beyond natural species range limits has not been fully explored within forest ecosystems. We used three experiments to isolate and quantify the effects of mycorrhizal colonization and common mycorrhizal networks (CMN) on tree seedling survival and growth across (within and beyond) the elevational ranges of two dominant tree species in northeastern North America, which were associated with either arbuscular mycorrhiza (AMF, <i>Acer saccharum</i>) or ectomycorrhiza (EMF, <i>Fagus grandifolia</i>). In order to quantify the influence of mycorrhiza on seedling establishment independent of soil chemistry and climate, we grew seedlings in soils from within and beyond our study species ranges in a greenhouse experiment (GE) as well as in the field using a soil translocation experiment (STE) and another field experiment manipulating seedling connections to potential CMNs (CMNE). Root length colonized, seedling survival and growth, foliar nutrients, and the presence of potential root pathogens were examined as metrics influencing plant performance across species' ranges. Mycorrhizal inoculum from within species ranges, but not from outside, increased seedling survival and growth in a greenhouse setting; however, only seedling survival, and not growth, was significantly improved in field studies. Sustained potential connectivity to AMF networks increased seedling survival across the entire elevational range of <i>A. saccharum</i>. Although seedlings disconnected from a potential CMN did not suffer decreased foliar nutrient levels compared with connected seedlings, disconnected AM seedlings, but not EM seedlings, had significantly higher aluminum concentrations and more potential pathogens present. Our results indicate that mycorrhizal fungi may facilitate tree seedling establishment beyond species range boundaries in this forested ecosystem and that the magnitude of this effect is modulated by the dominant mycorrhizal type present (i.e., AM vs. EM). Thus, despite changing climate conditions beyond species ranges, a lack of suitable mutualists can still limit successful seedling establishment and stall adaptive climate-induced shifts in tree species distributions.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The assembly and dynamics of ecological communities in an ever-changing world","authors":"Oscar Godoy,&nbsp;Fernando Soler-Toscano,&nbsp;José R. Portillo,&nbsp;José A. Langa","doi":"10.1002/ecm.1633","DOIUrl":"10.1002/ecm.1633","url":null,"abstract":"<p>Alternative perspectives on the maintenance of biodiversity and the assembly of ecological communities suggest that both processes cannot be investigated simultaneously. In this concept and synthesis, we challenge this view by presenting major theoretical advances in structural stability and permanence theory. These advances, which provide complementary views, allow studying the short- and long-term dynamics of ecological communities as changes in species richness, composition, and abundance. Here, the global attractor, technically named informational structure (IS), is the central element to construct from information of species' intrinsic growth rates and their strength and sign of interactions. The global attractor has four main properties: (1) It contains all the limits of what is feasible and unfeasible of the dynamical behavior of an ecological system, therefore, (2) it provides a thorough characterization of all combinations of species' richness and composition in which species can coexist (i.e., feasible and stable equilibrium), (3) as well as all connections (paths) of assembly between coexisting communities. Importantly, (4) such topology of coexisting communities and their connections changes when environmental (abiotic and biotic) variation affects the ability of species to grow and interact with others. Overall, these four properties allow switching from a traditional evaluation of species coexistence at equilibrium to a much more realistic nonequilibrium perspective where changes in the structure of the global attractor underlie the transient ecological dynamics. Several fields in ecology can benefit from the study of an IS. For instance, it can serve to evaluate community responses after the end of a perturbation, to design restoration trajectories, to study the consequences of biological invasions on the persistence of native species within communities, or to assess ecosystem health status. We illustrate this latter possibility with empirical observations of 7 years in Mediterranean annual grasslands. We document that extremely wet or dry years generate ISs supporting few coexisting communities and few assembly paths. The remaining communities distinguish winners from losers of ongoing climate change and indicate the limits to future community assembly opportunities. A fully tractable operational framework is readily available to understand and predict the assembly and dynamics of ecological communities in an ever-changing world.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1633","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142360589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Herbivore regulation of savanna vegetation: Structural complexity, diversity, and the complexity–diversity relationship","authors":"Tyler C. Coverdale,&nbsp;Peter B. Boucher,&nbsp;Jenia Singh,&nbsp;Todd M. Palmer,&nbsp;Jacob R. Goheen,&nbsp;Robert M. Pringle,&nbsp;Andrew B. Davies","doi":"10.1002/ecm.1624","DOIUrl":"10.1002/ecm.1624","url":null,"abstract":"<p>Large mammalian herbivores exert strong top-down control on plants, which in turn influence most ecological processes. Accordingly, the decline, displacement, or extinction of wild large herbivores in African savannas is expected to alter the physical structure of vegetation, the diversity of plant communities, and downstream ecosystem functions. However, herbivore impacts on vegetation comprise both direct and indirect effects and often depend on herbivore body size and plant type. Understanding how herbivores affect savanna vegetation requires disaggregating the effects of different herbivores and the responses of different plants, as well as accounting for both the structural complexity and composition of plant assemblages. We combined high-resolution Light Detection and Ranging (LiDAR) with field measurements from size-selective herbivore exclosures in Kenya to determine how herbivores affect the diversity and physical structure of vegetation, how these impacts vary with body size and plant type, and whether there are predictable associations between plant diversity and structural complexity. Herbivores generally reduced the diversity and abundance of both overstory and understory plants, though the magnitude of these impacts varied substantially as a function of body size and plant type: only megaherbivores (elephants and giraffes) affected tree cover, whereas medium- and small-bodied herbivores had stronger effects on herbaceous diversity and abundance. We also found evidence that herbivores altered the strength and direction of interactions between trees and herbaceous plants, with signatures of facilitation in the presence of herbivores and of competition in their absence. While megaherbivores uniquely affected tree structure, medium- and small-bodied species had stronger (and complementary) effects on metrics of herbaceous vegetation structure. Plant structural responses to herbivore exclusion were species-specific: of five dominant tree species, just three exhibited significant individual morphological variation across exclosure treatments, and the size class of herbivores responsible for these effects varied across species. Irrespective of exclosure treatment, more species-rich plant communities were more structurally complex. We conclude that the diversity and architecture of savanna vegetation depend on consumptive and nonconsumptive plant–herbivore interactions; the roles of herbivore diversity, body size, and plant traits in mediating those interactions; and a positive feedback between plant diversity and structural complexity.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142329998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global change experiments in mountain ecosystems: A systematic review","authors":"Matteo Dainese,&nbsp;Harald Crepaz,&nbsp;Roberta Bottarin,&nbsp;Veronika Fontana,&nbsp;Elia Guariento,&nbsp;Andreas Hilpold,&nbsp;Nikolaus Obojes,&nbsp;Chiara Paniccia,&nbsp;Alberto Scotti,&nbsp;Julia Seeber,&nbsp;Michael Steinwandter,&nbsp;Ulrike Tappeiner,&nbsp;Georg Niedrist","doi":"10.1002/ecm.1632","DOIUrl":"10.1002/ecm.1632","url":null,"abstract":"<p>Mountain ecosystems play an important role globally as centers of biodiversity and in providing ecosystem services to lowland populations, but are influenced by multiple global change drivers such as climate change, nitrogen deposition, or altered disturbance regimes. As global change is accelerating and the consequences for humans and nature are intensifying, there is an increasing demand for understanding and predicting the impacts and implications of global change on mountain ecosystems. Manipulation experiments are one of the major tools for testing the causal impacts of global change and establishing a mechanistic understanding of how these changes may transform the global biota from single organisms to entire ecosystems. Over the past three decades, hundreds of such experiments have been conducted in mountainous regions worldwide. To strengthen the experimental evidence for the possible ecological consequences of global change, we systematically reviewed the literature on global change experiments in mountains. We first investigated the spread of manipulation experiments to test the effects of different global change drivers on key biological and ecological processes from the organism to the ecosystem level. We then examined and discussed the balance of evidence regarding the impact of these global change drivers on biological and ecological processes, and outlined the possible consequences for mountain ecosystems. Finally, we identified research gaps and proposed future directions for global change research in mountain environments. Among the major drivers, temperature was manipulated most frequently, generally showing consistent strong impacts between biological and ecosystem processes, functional groups, and habitat types. There is also strong evidence suggesting that changes in water and nutrient availability have a direct impact on the life history and functioning of mountain organisms. Despite these important findings, there are several gaps that require urgent attention. These include experiments testing adult trees in tropical and boreal regions, assessing animal responses and biotic interactions, and investigating aquatic environments and soil systems more extensively. A broader approach that integrates experimental data with field observations and relies on international collaboration through coordinated experiments could help address these gaps and provide a more consistent and robust picture of the impacts of global change on mountain ecosystems.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1632","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142277001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parasites disrupt a keystone mutualism that underpins the structure, functioning, and resilience of a coastal ecosystem","authors":"Joseph P. Morton,&nbsp;Brian P. Davis,&nbsp;Taylor A. Walker,&nbsp;India H. Haber,&nbsp;Eve H. Adelson,&nbsp;Brian R. Silliman","doi":"10.1002/ecm.1630","DOIUrl":"10.1002/ecm.1630","url":null,"abstract":"<p>Parasites can alter the traits or densities of mutualistic partners, potentially destabilizing mutualistic associations that underpin the structure, functioning, and stability of entire ecosystems. Despite the potentially wide-ranging consequences of such disruptions, no studies have directly manipulated parasite prevalence and/or intensity in a mutualistic partner, nor quantified the resulting community-level effects. Here, we investigated the effects of a common trematode parasite (<i>Cercaria opaca</i>) on the strength of a keystone facultative mutualism in western Atlantic salt marshes between the foundational marsh cordgrass, <i>Spartina alterniflora</i>, and the ribbed mussel, <i>Geukensia demissa</i>. Cordgrass increases mussel survivorship and growth through shading, while mussels enhance cordgrass growth by producing nutrient-rich biodeposits. This mutualistic association also creates conditions that enhance biodiversity and ecosystem functioning, and mediates the ability of foundational plants to resist and recover from extreme drought. We used lab and field assays to show how increasing infection with trematode metacercariae negatively influenced mussel biodeposit production, as well as the strength of mussel shells and byssal attachments. By conducting a field manipulation using experimentally infected mussels, we demonstrated that the mutualistic benefits of mussels to cordgrass growth decreased with increasing trematode infection intensity—a pattern likely generated by reduced mussel biodeposition and enhanced mortality. Additionally, increasing parasite loads in mussels led to predictable decreases in the abundances of benthic invertebrates, as well as in key ecosystem characteristics and process rates (i.e., redox potential and sediment accretion). Finally, a survey of five North Carolina salt marshes demonstrated that infection with <i>C. opaca</i> was most common in mussels in areas experiencing cordgrass die-off due to drought, and that infection intensity decreased with distance from die-off areas. Because the mussel–cordgrass mutualism underpins marsh ecosystem resilience to drought-associated die-off, our results suggest that parasitism may depress recovery from these disturbances. Although this is the first experimental demonstration of parasites indirectly altering community structure and functioning by undermining an ecologically influential mutualism, this type of relationship could be common in nature, given that parasites frequently infect influential mutualists.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142235505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An integrative paradigm for building causal knowledge","authors":"James B. Grace","doi":"10.1002/ecm.1628","DOIUrl":"10.1002/ecm.1628","url":null,"abstract":"<p>A core aspiration of the ecological sciences is to determine how systems work, which implies the challenge of developing a causal understanding. Causal inference has long been approached from a statistical perspective, which can be limited and restrictive for a variety of reasons. Ecologists and other natural scientists have historically pursued mechanistic knowledge as an alternative approach to causal understanding, though without explicit reference to the requirements of causal statistics. In this paper, I describe the premises of an expanded paradigm for causal studies, the Integrative Causal Investigation Paradigm, that subsumes causal statistics and mechanistic investigation into a multi-evidence approach. This paradigm is distinct from the one articulated by causal statistics in that it (1) focuses its attention on the long-term goal of building causal knowledge across multiple studies and (2) recognizes the essential role of mechanistic investigations in establishing a causal understanding. The Integrative Paradigm, consequentially, proposes that there are multiple methodological routes to building causal knowledge and thus represents a pluralistic perspective. This paper begins by describing the crux of the problem faced by causal statistics. To understand this problem, it should be recognized that the word <i>causal</i> has multiple meanings and a variety of evidential standards. An expanded vocabulary is developed so as to reduce ambiguities and clarify critical issues. I further show by example that there is an important ingredient typically omitted from consideration in causal statistics, which is the known information related to the mechanisms underlying relationships being evaluated. To address this issue, I describe a procedure, Causal Knowledge Analysis, that involves an evaluation and compilation of existing evidence indicative of causal content and the features of mechanisms. Causal Knowledge Analysis is applied to three example situations to illustrate the process and its potential for contributing to the development of causal knowledge. The implications of adopting the proposed paradigm and associated procedures are discussed and include the potential for advancing ecology, the potential for clarifying causal methodology, and the potential for contributing to predictive forecasting.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1628","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal biology diversity of bee pollinators: Taxonomic, phylogenetic, and plant community-level correlates","authors":"Carlos M. Herrera","doi":"10.1002/ecm.1625","DOIUrl":"10.1002/ecm.1625","url":null,"abstract":"<p>Community-wide assembly of plant–pollinator systems depends on an intricate combination of biotic and abiotic factors, including heterogeneity among pollinators in thermal biology and responses to abiotic factors. Studies on the thermal biology of pollinators have mostly considered only one or a few species of plants or pollinators at a time, and the possible driving role of the diversity in thermal biology of pollinator asemblages at the plant community level remains largely unexplored. More specifically, it is unknown whether diversity in the thermal biology of bees, a major pollinator group worldwide, contributes to the assembly and maintenance of diverse bee communities; broadens the spectrum of possibilities available to bee-pollinated plants; facilitates interspecific partitioning of ecological gradients across habitats, seasons, and time of day; and/or enhance plant pollination success through complementarity effects. The objectives of this study were to assess the diversity in thermal biology of the bee assemblage that pollinates plants in a Mediterranean montane area, evaluate its taxonomic and phylogenetic underpinnings, and elucidate whether there existed seasonal, daily, between-habitat, or floral visitation correlates of bee thermal biology which could contribute to partition ecological gradients among plant and bee species. Thermal biology parameters were obtained in the laboratory (<i>K</i>, intrinsic warming constant) and the field (thoracic and ambient temperature at foraging site, <i>T</i>_th and <i>T</i>_air) on individual bees of a diverse sample (<i>N</i> = 204 bee species) comprising most bee pollinators of the regional plant community. Species-specific thermal biology parameters were combined with quantitative field data on bee pollinators and flower visitation for the regional community of entomophilous plants (<i>N</i> = 292 plant species). Results revealed that the regional bee assemblage harbored considerable diversity in thermal biology features; that such diversity was mostly taxonomically, phylogenetically, and body-size structured; and that the broad interspecific heterogeneity in thermal biology represented in the bee community as a whole eventually translated into daily, seasonal, among-habitat, and flower visitation patterns at the plant community level. This lends support to the hypothesis that broad diversity in thermal biology of bees can enhance opportunities for bee coexistence, spatiotemporal partitioning of floral resources, and plant pollination success.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1625","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142142899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The enigmatic life history of the bamboo explained as a strategy to arrest succession","authors":"Aiyu Zheng,&nbsp;Stephen W. Pacala","doi":"10.1002/ecm.1621","DOIUrl":"10.1002/ecm.1621","url":null,"abstract":"<p>Bamboos are perennial woody grasses that display an enigmatic mix of traits. Bamboo is highly shade intolerant like early-successional trees. Without secondary xylem, bamboos cannot continue to grow once they reach a maximum height or replace xylem damaged by hydraulic stress and must instead replace each stem after a few years using vegetative propagation via rhizomes. These traits of bamboo would appear to make them inferior to trees in competition for both light and water in all but early-successional wet locations. However, some species competitively exclude trees and form persistent monodominant stands across large areas in tropical and temperate forests, including areas that are not mesic. Moreover, bamboo paradoxically postpones seed production for decades to over a century, and then flowers semelparously and dies synchronously. The delayed reproduction appears to be inconsistent with an early-successional strategy to colonize disturbed areas as soon as they form, while the simultaneous death over large areas appears to be inconsistent with a late-successional strategy to gain and hold space. Bamboo exhibits great diversity in its growth form and life histories along the tropical-temperate geographical cline, with tropical bamboo being taller with shorter rhizome lengths and flowering interval lengths than temperate bamboo. We hypothesize that all of the above characteristics of bamboo are essential elements of competitive strategies to arrest succession in a lineage that lacks secondary xylem. To develop this Arrested Succession Hypothesis, we construct mathematical models of competition for recently disturbed areas between a tree species and a species with bamboo's enigmatic characteristics. We modeled the growth of bamboo genetic individuals from seedlings after seed germination to clonal culms at mass flowering and then placed these individuals in competition with one another and with trees in simple models of competition for light. Results explain how bamboo's traits allow it to persist in forests late in succession despite its hydraulic disadvantages, and form monodominant stands in the temperate zone, but not in tropical forests. They explain why bamboo is semelparous with synchronized reproduction, and why maximum culm size and age, reproductive interval, and rhizome length differ between the tropics and the temperate zone.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1621","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142118215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New theoretical and analytical framework for quantifying and classifying ecological niche differentiation","authors":"Alfredo Ascanio,&nbsp;Jason T. Bracken,&nbsp;Martin Henry H. Stevens,&nbsp;Tereza Jezkova","doi":"10.1002/ecm.1622","DOIUrl":"10.1002/ecm.1622","url":null,"abstract":"<p>Ecological niche differentiation is a process that accompanies lineage diversification and community assembly. Traditionally, the degree of niche differentiation is estimated by contrasting niche hypervolumes of two taxa, reconstructed using ecologically relevant variables. These methods disregard the fact that niches can shift in different ways and directions. Without means of discriminating between different types of niche differentiation, important evolutionary and ecological patterns may go unrecognized. Herein, we introduce a new conceptual and methodological framework that allows quantification and classification of niche differentiation and divergence between taxa along single niche axis. This new method, the Niche Divergence Plane, is based on species' responses to an underlying environmental gradient, from which we derive a two-dimensional plane defined by two indices, niche exclusivity and niche dissimilarity. These two indices identify the proportion of the environmental gradient that is unique to each species, that is, how much of the environmental gradient species do not share (niche breadth exclusivity) and how different the species' responses are along the environmental gradient (niche dissimilarity). Thus, the latter can also be seen as a measure of the differences in niche preference or importance, even when there is significant overlap in niche breadth (i.e., low niche exclusivity). Based on the position of the two indices on the divergence plane, we can distinguish niche conservatism from four other general types of niche divergence: hard, soft, weighted, and nested. We demonstrate that the Niche Divergence Plane complements traditional measures of niche similarity (e.g., Schoener's <i>D</i> or Hellinger's <i>I</i>). Additionally, we show an empirical comparison using the Niche Divergence Plane framework on two <i>Ambystoma</i> salamanders. Overall, we demonstrate that the Niche Divergence Plane is a versatile tool that can be used to complement and expand previous methods of ecological niche comparisons and the study of ecological niche divergence.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"94 4","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1622","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141918899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}