Ecological Monographs最新文献

{"title":"Scale-dependent diversity–biomass relationships can be driven by tree mycorrhizal association and soil fertility","authors":"Zikun Mao,&nbsp;Fons van der Plas,&nbsp;Adriana Corrales,&nbsp;Kristina J. Anderson-Teixeira,&nbsp;Norman A. Bourg,&nbsp;Chengjin Chu,&nbsp;Zhanqing Hao,&nbsp;Guangze Jin,&nbsp;Juyu Lian,&nbsp;Fei Lin,&nbsp;Buhang Li,&nbsp;Wenqi Luo,&nbsp;William J. McShea,&nbsp;Jonathan A. Myers,&nbsp;Guochun Shen,&nbsp;Xihua Wang,&nbsp;En-Rong Yan,&nbsp;Ji Ye,&nbsp;Wanhui Ye,&nbsp;Zuoqiang Yuan,&nbsp;Xugao Wang","doi":"10.1002/ecm.1568","DOIUrl":"10.1002/ecm.1568","url":null,"abstract":"<p>Diversity–biomass relationships (DBRs) often vary with spatial scale in terrestrial ecosystems, but the mechanisms driving these scale-dependent patterns remain unclear, especially for highly heterogeneous forest ecosystems. This study explores how mutualistic associations between trees and different mycorrhizal fungi, i.e., arbuscular mycorrhizal (AM) vs. ectomycorrhizal (EM) association, modulate scale-dependent DBRs. We hypothesized that in soil-heterogeneous forests with a mixture of AM and EM tree species, (i) AM and EM tree species would respond in contrasting ways (i.e., positively vs. negatively, respectively) to increasing soil fertility, (ii) AM tree dominance would contribute to higher tree diversity and EM tree dominance to greater standing biomass, and that as a result (iii) mycorrhizal associations would exert an overall negative effect on DBRs across spatial scales. To empirically test these hypotheses, we collected detailed tree distribution and soil information (e.g., nitrogen, phosphorus, organic matter, pH) from seven temperate and subtropical AM–EM mixed forest megaplots (16–50 ha). Using a spatial codispersion null model and structural equation modeling, we identified the relationships among AM or EM tree dominance, soil fertility, tree species diversity, and biomass and, thus, DBRs across 0.01- to 1-ha scales. We found the first evidence overall supporting the three aforementioned hypotheses in these AM–EM mixed forests: (i) In most forests, with increasing soil fertility, tree communities changed from EM-dominated to AM-dominated; (ii) increasing AM tree dominance had an overall positive effect on tree diversity and a negative effect on biomass, even after controlling for soil fertility and number of trees. Together, (iii) the changes in mycorrhizal dominance along soil fertility gradients weakened the positive DBR observed at 0.01- to 0.04-ha scales in nearly all forests and drove negative DBRs at 0.25- to 1-ha scales in four out of seven forests. Hence, this study highlights a soil-related mycorrhizal dominance mechanism that could partly explain why, in many natural forests, biodiversity–ecosystem functioning (BEF) relationships shift from positive to negative with increasing spatial scale.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 2","pages":""},"PeriodicalIF":6.1,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42749498","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":"Underlying geology and climate interactively shape climate change refugia in mountain streams","authors":"Nobuo Ishiyama,&nbsp;Masanao Sueyoshi,&nbsp;Jorge García Molinos,&nbsp;Kenta Iwasaki,&nbsp;Junjiro N. Negishi,&nbsp;Itsuro Koizumi,&nbsp;Shigeya Nagayama,&nbsp;Akiko Nagasaka,&nbsp;Yu Nagasaka,&nbsp;Futoshi Nakamura","doi":"10.1002/ecm.1566","DOIUrl":"10.1002/ecm.1566","url":null,"abstract":"<p>Identifying climate-change refugia is a key adaptation strategy for reducing global warming impacts. Knowledge of the effects of underlying geology on thermal regime along climate gradients and the ecological responses to the geology-controlled thermal regime is essential to plan appropriate climate adaptation strategies. In the present study, the dominance of volcanic rocks in the watershed is used as a landscape-scale surrogate for cold groundwater inputs to clarify the importance of underlying geology in stream ecosystems along climate gradients. First, using hundreds of monitoring stations distributed across multiple catchments, we explored the relationship between watershed geology and the mean summer water temperature of mountain streams along climate gradients in the Japanese archipelago. Mean summer water temperature was explained by the interaction between the watershed geology and climate in addition to independent effects. The cooling effect supported by volcanic rocks reached up to 3.3°C among study regions, which was more pronounced in streams with less summer precipitation or lower air temperatures. Next, we examined the function of volcanic streams as cold refugia under contemporary and future climatic conditions. Community composition analyses revealed that volcanic streams hosted distinct stream communities composed of more cold-water species compared with nonvolcanic streams. Scenario analyses based on multiple global climate models and Representative Concentration Pathways (RCPs) revealed a geology-related pattern of thermal habitat loss for cold-water species. Nonvolcanic streams rapidly declined in thermally suitable habitats for lotic sculpins even under the lowest emission scenario (RCP 2.6). In contrast, most volcanic streams will be sustained below the thermal threshold, especially for low- and mid-level emission scenarios (RCP 2.6, 4.5). However, the distinct stream community in volcanic streams and geology-dependent habitat loss for lotic sculpins was not uniform and were more pronounced in streams with less summer precipitation or lower air temperatures. These findings highlight that underlying geology, climate variability, and their interaction should be considered simultaneously for the effective management of climate-change refugia in mountain streams.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 2","pages":""},"PeriodicalIF":6.1,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42604083","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":"Hydrodynamics structure plankton communities and interactions in a freshwater tidal estuary","authors":"Adrianne P. Smits,&nbsp;Luke C. Loken,&nbsp;Erwin E. Van Nieuwenhuyse,&nbsp;Matthew J. Young,&nbsp;Paul R. Stumpner,&nbsp;Leah E. K. Lenoch,&nbsp;Jon R. Burau,&nbsp;Randy A. Dahlgren,&nbsp;Tiffany Brown,&nbsp;Steven Sadro","doi":"10.1002/ecm.1567","DOIUrl":"10.1002/ecm.1567","url":null,"abstract":"<p>Drivers of phytoplankton and zooplankton dynamics vary spatially and temporally in estuaries due to variation in hydrodynamic exchange and residence time, complicating efforts to understand controls on food web productivity. We conducted approximately monthly (2012–2019; <i>n</i> = 74) longitudinal sampling at 10 fixed stations along a freshwater tidal terminal channel in the San Francisco Estuary, California, characterized by seaward to landward gradients in water residence time, turbidity, nutrient concentrations, and plankton community composition. We used multivariate autoregressive state space (MARSS) models to quantify environmental (abiotic) and biotic controls on phytoplankton and mesozooplankton biomass. The importance of specific abiotic drivers (e.g., water temperature, turbidity, nutrients) and trophic interactions differed significantly among hydrodynamic exchange zones with different mean residence times. Abiotic drivers explained more variation in phytoplankton and zooplankton dynamics than a model including only trophic interactions, but individual phytoplankton–zooplankton interactions explained more variation than individual abiotic drivers. Interactions between zooplankton and phytoplankton were strongest in landward reaches with the longest residence times and the highest zooplankton biomass. Interactions between cryptophytes and both copepods and cladocerans were stronger than interactions between bacillariophytes (diatoms) and zooplankton taxa, despite contributing less biovolume in all but the most landward reaches. Our results demonstrate that trophic interactions and their relative strengths vary in a hydrodynamic context, contributing to food web heterogeneity within estuaries at spatial scales smaller than the freshwater to marine transition.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 2","pages":""},"PeriodicalIF":6.1,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1567","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49187880","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":"Using a demographic model to project the long-term effects of fire management on tree biomass in Australian savannas","authors":"Brett P. Murphy,&nbsp;Peter J. Whitehead,&nbsp;Jay Evans,&nbsp;Cameron P. Yates,&nbsp;Andrew C. Edwards,&nbsp;Harry J. MacDermott,&nbsp;Dominique C. Lynch,&nbsp;Jeremy Russell-Smith","doi":"10.1002/ecm.1564","DOIUrl":"10.1002/ecm.1564","url":null,"abstract":"<p>Tropical savannas are characterized by high primary productivity and high fire frequency, such that much of the carbon captured by vegetation is rapidly returned to the atmosphere. Hence, there have been suggestions that management-driven reductions in savanna fire frequency and/or severity could significantly reduce greenhouse gas emissions and sequester carbon in tree biomass. However, a key knowledge gap is the extent to which savanna tree biomass will respond to modest shifts in fire regimes due to plausible, large-scale management interventions. Here, we: (1) characterize relationships between the frequency and severity of fires and key demographic rates of savanna trees, based on long-term observations in vegetation monitoring plots across northern Australia; (2) use these relationships to develop a process-explicit demographic model describing the effects of fire on savanna tree populations; and (3) use the demographic model to address the question: to what extent is it feasible, through the strategic application of prescribed burning, to increase tree biomass in Australian tropical savannas? Our long-term tree monitoring dataset included observations of 12,344 tagged trees in 236 plots, monitored for between 3 and 24 years. Analysis of this dataset showed that frequent high-severity fires significantly reduced savanna tree recruitment, survival, and growth. Our demographic model suggested that: (1) despite the negative effects of frequent high-severity fires on demographic rates, savanna tree biomass appears to be suppressed by only a relatively small amount by contemporary fire regimes, characterized by a mix of low- to high-severity fires; and (2) plausible, management-driven reductions in the frequency of high-severity fires are likely to lead to increases in tree biomass of about 11.0 t DM ha⁻¹ (95% CI: −1.2–20.8) over a century. Accounting for this increase in carbon storage could generate significant carbon credits, worth, on average, three times those generated annually by current greenhouse gas (methane and nitrous oxide) abatement projects, and has the potential to significantly increase the economic viability of fire/carbon projects, thereby promoting ecologically sustainable management of tropical savannas in Australia and elsewhere. This growing industry has the potential to bring much-needed economic activity to savanna landscapes, without compromising important natural and cultural values.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 2","pages":""},"PeriodicalIF":6.1,"publicationDate":"2023-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1564","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47216891","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":"Tree symbioses sustain nitrogen fixation despite excess nitrogen supply","authors":"Duncan N. L. Menge,&nbsp;Amelia A. Wolf,&nbsp;Jennifer L. Funk,&nbsp;Steven S. Perakis,&nbsp;Palani R. Akana,&nbsp;Rachel Arkebauer,&nbsp;Thomas A. Bytnerowicz,&nbsp;K. A. Carreras Pereira,&nbsp;Alexandra M. Huddell,&nbsp;Sian Kou-Giesbrecht,&nbsp;Sarah K. Ortiz","doi":"10.1002/ecm.1562","DOIUrl":"10.1002/ecm.1562","url":null,"abstract":"<p>Symbiotic nitrogen fixation (SNF) is a key ecological process whose impact depends on the strategy of SNF regulation—the degree to which rates of SNF change in response to limitation by N versus other resources. SNF that is obligate or exhibits incomplete downregulation can result in excess N fixation, whereas a facultative SNF strategy does not. We hypothesized that tree-based SNF strategies differed by latitude (tropical vs. temperate) and symbiotic type (actinorhizal vs. rhizobial). Specifically, we expected tropical rhizobial symbioses to display strongly facultative SNF as an explanation of their success in low-latitude forests. In this study we used ¹⁵N isotope dilution field experiments in New York, Oregon, and Hawaii to determine SNF strategies in six N-fixing tree symbioses. Nitrogen fertilization with +10 and +15 g N m⁻² year⁻¹ for 4–5 years alleviated N limitation in all taxa, paving the way to determine SNF strategies. Contrary to our hypothesis, all six of the symbioses we studied sustained SNF even at high N. <i>Robinia pseudoacacia</i> (temperate rhizobial) fixed 91% of its N (%N_dfa) in controls, compared to 64% and 59% in the +10 and +15 g N m⁻² year⁻¹ treatments. For <i>Alnus rubra</i> (temperate actinorhizal), %N_dfa was 95%, 70%, and 60%. For the tropical species, %N_dfa was 86%, 80%, and 82% for <i>Gliricidia sepium</i> (rhizobial); 79%, 69%, and 67% for <i>Casuarina equisetifolia</i> (actinorhizal); 91%, 42%, and 67% for <i>Acacia koa</i> (rhizobial); and 60%, 51%, and 19% for <i>Morella faya</i> (actinorhizal). Fertilization with phosphorus did not stimulate tree growth or SNF. These results suggest that the latitudinal abundance distribution of N-fixing trees is not caused by a shift in SNF strategy. They also help explain the excess N in many forests where N fixers are common.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 2","pages":""},"PeriodicalIF":6.1,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44704545","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":"Abiotic and biotic drivers of tree trait effects on soil microbial biomass and soil carbon concentration","authors":"Rémy Beugnon,&nbsp;Wensheng Bu,&nbsp;Helge Bruelheide,&nbsp;Andréa Davrinche,&nbsp;Jianqing Du,&nbsp;Sylvia Haider,&nbsp;Matthias Kunz,&nbsp;Goddert von Oheimb,&nbsp;Maria D. Perles-Garcia,&nbsp;Mariem Saadani,&nbsp;Thomas Scholten,&nbsp;Steffen Seitz,&nbsp;Bala Singavarapu,&nbsp;Stefan Trogisch,&nbsp;Yanfen Wang,&nbsp;Tesfaye Wubet,&nbsp;Kai Xue,&nbsp;Bo Yang,&nbsp;Simone Cesarz,&nbsp;Nico Eisenhauer","doi":"10.1002/ecm.1563","DOIUrl":"10.1002/ecm.1563","url":null,"abstract":"<p>Forests are ecosystems critical to understanding the global carbon budget, due to their carbon sequestration potential in both aboveground and belowground compartments, especially in species-rich forests. Soil carbon sequestration is strongly linked to soil microbial communities, and this link is mediated by the tree community, likely due to modifications of microenvironmental conditions (i.e., biotic conditions, soil properties, and microclimate). We studied soil carbon concentration and the soil microbial biomass of 180 local neighborhoods along a gradient of tree species richness ranging from 1 to 16 tree species per plot in a Chinese subtropical forest experiment (BEF-China). Tree productivity and different tree functional traits were measured at the neighborhood level. We tested the effects of tree productivity, functional trait identity, and dissimilarity on soil carbon concentrations, and their mediation by the soil microbial biomass and microenvironmental conditions. Our analyses showed a strong positive correlation between soil microbial biomass and soil carbon concentrations. In addition, soil carbon concentration increased with tree productivity and tree root diameter, while it decreased with litterfall C:N content. Moreover, tree productivity and tree functional traits (e.g., fungal root association and litterfall C:N ratio) modulated microenvironmental conditions with substantial consequences for soil microbial biomass. We also showed that soil history and topography should be considered in future experiments and tree plantations, as soil carbon concentrations were higher at sites where historical (i.e., at the beginning of the experiment) carbon concentrations were high, themselves being strongly affected by the topography. Altogether, these results implied that the quantification of the different soil carbon pools is critical for understanding microbial community–soil carbon stock relationships and their dependence on tree diversity and microenvironmental conditions.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 2","pages":""},"PeriodicalIF":6.1,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1563","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49043890","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":"Interspecific differences in microhabitat use expose insects to contrasting thermal mortality","authors":"Maria Vives-Ingla,&nbsp;Javier Sala-Garcia,&nbsp;Constantí Stefanescu,&nbsp;Armand Casadó-Tortosa,&nbsp;Meritxell Garcia,&nbsp;Josep Peñuelas,&nbsp;Jofre Carnicer","doi":"10.1002/ecm.1561","DOIUrl":"10.1002/ecm.1561","url":null,"abstract":"<p>Ecotones linking open and forested habitats contain multiple microhabitats with varying vegetal structures and microclimatic regimes. Ecotones host many insect species whose development is intimately linked to the microclimatic conditions where they grow (e.g., the leaves of their host plants and the surrounding air). Yet microclimatic heterogeneity at these fine scales and its effects on insects remain poorly quantified for most species. Here we studied how interspecific differences in the use of microhabitats across ecotones lead to contrasting thermal exposure and survival costs between two closely-related butterflies (<i>Pieris napi</i> and <i>P. rapae</i>). We first assessed whether butterflies selected different microhabitats to oviposit and quantified the thermal conditions at the microhabitat and foliar scales. We also assessed concurrent changes in the quality and availability of host plants. Finally, we quantified larval time of death under different experimental temperatures (thermal death time [TDT] curves) to predict their thermal mortality considering both the intensity and the duration of the microclimatic heat challenges in the field. We identified six processes determining larval thermal exposure at fine scales associated with butterfly oviposition behavior, canopy shading, and heat and water fluxes at the soil and foliar levels. Leaves in open microhabitats could reach temperatures 3–10°C warmer than the surrounding air while more closed microhabitats presented more buffered and homogeneous temperatures. Interspecific differences in microhabitat use matched the TDT curves and the thermal mortality in the field. Open microhabitats posed acute heat challenges that were better withstood by the thermotolerant butterfly, <i>P. rapae</i>, where the species mainly laid their eggs. Despite being more thermosensitive, <i>P. napi</i> was predicted to present higher survivals than <i>P. rapae</i> due to the thermal buffering provided by their selected microhabitats. However, its offspring could be more vulnerable to host-plant scarcity during summer drought periods. Overall, the different interaction of the butterflies with microclimatic and host-plant variation emerging at fine scales and their different thermal sensitivity posed them contrasting heat and resource challenges. Our results contribute to setting a new framework that predicts insect vulnerability to climate change based on their thermal sensitivity and the intensity, duration, and accumulation of their heat exposure.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 2","pages":""},"PeriodicalIF":6.1,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1561","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49490468","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":"Partner fidelity and environmental filtering preserve stage-specific turtle ant gut symbioses for over 40 million years","authors":"Yi Hu,&nbsp;Catherine L. D'Amelio,&nbsp;Benoît Béchade,&nbsp;Christian S. Cabuslay,&nbsp;Piotr Łukasik,&nbsp;Jon G. Sanders,&nbsp;Shauna Price,&nbsp;Emily Fanwick,&nbsp;Scott Powell,&nbsp;Corrie S. Moreau,&nbsp;Jacob A. Russell","doi":"10.1002/ecm.1560","DOIUrl":"https://doi.org/10.1002/ecm.1560","url":null,"abstract":"Sustaining beneficial gut symbioses presents a major challenge for animals, including holometabolous insects. Social insects may meet such challenges through partner fidelity, aided by behavioral symbiont transfer and transgenerational inheritance through colony founders. We address such potential through colony-wide explorations across 13 eusocial, holometabolous insect species in the ant genus Cephalotes . Through amplicon sequencing, we show that previously characterized worker microbiomes are conserved in sol-dier castes, that adult microbiomes exhibit trends of phylosymbiosis","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2022-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1560","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50123837","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":"Climate-mediated population dynamics of a migratory songbird differ between the trailing edge and range core","authors":"William B. Lewis,&nbsp;Robert J. Cooper,&nbsp;Richard B. Chandler,&nbsp;Ryan W. Chitwood,&nbsp;Mason H. Cline,&nbsp;Michael T. Hallworth,&nbsp;Joanna L. Hatt,&nbsp;Jeff Hepinstall-Cymerman,&nbsp;Sara A. Kaiser,&nbsp;Nicholas L. Rodenhouse,&nbsp;T. Scott Sillett,&nbsp;Kirk W. Stodola,&nbsp;Michael S. Webster,&nbsp;Richard T. Holmes","doi":"10.1002/ecm.1559","DOIUrl":"10.1002/ecm.1559","url":null,"abstract":"<p>Understanding the demographic drivers of range contractions is important for predicting species' responses to climate change; however, few studies have examined the effects of climate change on survival and recruitment across species' ranges. We show that climate change can drive trailing edge range contractions through the effects on apparent survival, and potentially recruitment, in a migratory songbird. We assessed the demographic drivers of trailing edge range contractions using a long-term demography dataset for the black-throated blue warbler (<i>Setophaga caerulescens</i>) collected across elevational climate gradients at the trailing edge and core of the breeding range. We used a Bayesian hierarchical model to estimate the effect of climate change on apparent survival and recruitment and to forecast population viability at study plots through 2040. The trailing edge population at the low-elevation plot became locally extinct by 2017. The local population at the mid-elevation plot at the trailing edge gradually declined and is predicted to become extirpated by 2040. Population declines were associated with warming temperatures at the mid-elevation plot, although results were more equivocal at the low-elevation plot where we had fewer years of data. Population density was stable or increasing at the range core, although warming temperatures are predicted to cause population declines by 2040 at the low-elevation plot. This result suggests that even populations within the geographic core of the range are vulnerable to climate change. The demographic drivers of local population declines varied between study plots, but warming temperatures were frequently associated with declining rates of population growth and apparent survival. Declining apparent survival in our study system is likely to be associated with increased adult emigration away from poor-quality habitats. Our results suggest that demographic responses to warming temperatures are complex and dependent on local conditions and geographic range position, but spatial variation in population declines is consistent with the climate-mediated range shift hypothesis. Local populations of black-throated blue warblers near the warm-edge range boundary at low latitudes and low elevations are likely to be the most vulnerable to climate change, potentially leading to local extirpation and range contractions.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://esajournals.onlinelibrary.wiley.com/doi/epdf/10.1002/ecm.1559","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9642160","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 geographic footprint of mutualism: How mutualists influence species' range limits","authors":"Joshua C. Fowler,&nbsp;Marion L. Donald,&nbsp;Judith L. Bronstein,&nbsp;Tom E. X. Miller","doi":"10.1002/ecm.1558","DOIUrl":"10.1002/ecm.1558","url":null,"abstract":"<p>Understanding mechanisms that generate range limits is central to knowing why species are found where they are and how they will respond to environmental change. There is growing awareness that biotic interactions play an important role in generating range limits. However, current theory and data overwhelmingly focus on abiotic drivers and antagonistic interactions. Here we explore the effect that mutualists have on their partner's range limits: the geographic “footprint” of mutualism. This footprint arises from two general processes: modification of a partner's niche through environment-dependent fitness effects and, for a subset of mutualisms, dispersal opportunities that lead suitable habitats to be filled. We developed a conceptual framework that organizes different footprints of mutualism and the underlying mechanisms that shape them, and evaluated supporting empirical evidence from the primary literature. In the available literature, we found that the fitness benefits and dispersal opportunities provided by mutualism can extend species' ranges; conversely, the absence of mutualism can constrain species from otherwise suitable regions of their range. Most studies found that the footprint of mutualism is driven by changes in the frequency of mutualist partners from range core to range edge, whereas fewer found changes in interaction outcomes, the diversity of partners, or varying sensitivities of fitness to the effects of mutualists. We discuss these findings with respect to specialization, dependence, and intimacy of mutualism. Much remains unknown about the geographic footprint of mutualisms, leaving fruitful areas for future work. A particularly important future direction is to explore the role of mutualism during range shifts under global change, including the promotion of shifts at leading edges and persistence at trailing edges.</p>","PeriodicalId":11505,"journal":{"name":"Ecological Monographs","volume":"93 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43541236","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}