Asma Bourougaaoui, Christelle Robinet, Mohamed L. Ben Jamâa, Mathieu Laparie
Ectotherms are largely impacted by extreme climate events, essentially heatwaves. In Tunisia, the pine processionary moth (PPM), Thaumetopoea pityocampa, is a defoliator typically laying eggs in summer. Its geographical range is expanding northwards in Europe while retracting from southern Tunisia where summer temperatures can reach extreme heats. We explored the effects of climate change over the last 30 years on PPM at its southern range edge. We investigated variations of fecundity and causes of egg mortality over time using historical and contemporary collections of egg masses. Due to incomplete historical series, a clustering method was used to group climatically homologous sampling sites and perform allochronic analyses on clusters instead of individual localities. Our results suggest negative effects of summer heat on egg survival, down to 0% hatching rate in one site during a major heatwave. Such high hatching failures resulted partly from high egg sterility and aborted embryos, with little effects of parasitism rate, suggesting heat susceptibility during embryonic development, but our results do not allow distinguishing impeded mating success from failed egg maturation or early embryo death. Decreasing female fecundity was observed in regions where allochronic comparisons were possible, associated with a decrease in parasitism rate, while climatic variability increased. Previous studies have confirmed experimentally the thermal sensitivity of PPM early instars to temperatures observed in the present work, including one population from southern Tunisia. However, further work is required to evaluate the relative importance of warming summers among populations, since the risk of heat stress depends on the phenology of sensitive instars, and populations from the warmest areas may not necessarily be the most vulnerable to climate change if they already evolved phenological heat avoidance. In addition to heat‐induced mortality, the ultimate fitness of heat survivors should also be explored to determine potential carry‐over effects on subsequent life stages.
{"title":"A retrospective analysis on the effects of climate warming on the pine processionary moth at the southern edge of its range","authors":"Asma Bourougaaoui, Christelle Robinet, Mohamed L. Ben Jamâa, Mathieu Laparie","doi":"10.1111/oik.10989","DOIUrl":"https://doi.org/10.1111/oik.10989","url":null,"abstract":"Ectotherms are largely impacted by extreme climate events, essentially heatwaves. In Tunisia, the pine processionary moth (PPM), <jats:italic>Thaumetopoea pityocampa</jats:italic>, is a defoliator typically laying eggs in summer. Its geographical range is expanding northwards in Europe while retracting from southern Tunisia where summer temperatures can reach extreme heats. We explored the effects of climate change over the last 30 years on PPM at its southern range edge. We investigated variations of fecundity and causes of egg mortality over time using historical and contemporary collections of egg masses. Due to incomplete historical series, a clustering method was used to group climatically homologous sampling sites and perform allochronic analyses on clusters instead of individual localities. Our results suggest negative effects of summer heat on egg survival, down to 0% hatching rate in one site during a major heatwave. Such high hatching failures resulted partly from high egg sterility and aborted embryos, with little effects of parasitism rate, suggesting heat susceptibility during embryonic development, but our results do not allow distinguishing impeded mating success from failed egg maturation or early embryo death. Decreasing female fecundity was observed in regions where allochronic comparisons were possible, associated with a decrease in parasitism rate, while climatic variability increased. Previous studies have confirmed experimentally the thermal sensitivity of PPM early instars to temperatures observed in the present work, including one population from southern Tunisia. However, further work is required to evaluate the relative importance of warming summers among populations, since the risk of heat stress depends on the phenology of sensitive instars, and populations from the warmest areas may not necessarily be the most vulnerable to climate change if they already evolved phenological heat avoidance. In addition to heat‐induced mortality, the ultimate fitness of heat survivors should also be explored to determine potential carry‐over effects on subsequent life stages.","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"100 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Alice Brambilla, Achaz von Hardenberg, Bruno Bassano, Luigi Ranghetti, Lukas Keller, Marco Festa‐Bianchet
Climate affects seasonality and plant phenology, which can influence seasonal body mass dynamics of herbivores in temperate environments. We investigated long‐term trends of seasonal body mass changes in male Alpine ibex Capra ibex. We used SEM to test direct and indirect relationships between body mass, mass changes and environmental and climatic variables. Individually recognizable Alpine ibex were weighed repeatedly between 2000 and 2022 in Gran Paradiso National Park (Italy). Autumn mass increased substantially over these two decades, up to 15% in some age classes. Over the same time frame, both summer mass gain and winter mass loss decreased, suggesting that heavier autumn body mass was due to the cumulative effects of reduced mass loss over several winters. The environmental factor with the strongest effects on winter mass changes was the starting date of vegetation green‐up at low altitude, where ibex gather after winter to feed on new growth vegetation. Early springs led to lower winter mass loss, likely because ibex relied on stored fat for a shorter period and had greater access to forage. High population density also increased winter mass loss. Environmental conditions and resource availability, possibly also influenced by density in winter and early spring, seem therefore to directly affect the body mass dynamics of male Alpine ibex, while the effect of summer conditions appears less relevant. By affecting seasonal body mass dynamics, climate change may have consequences for life history and population dynamics of mountain herbivores, for example via earlier access of young males to reproduction.
气候会影响季节性和植物物候，从而影响温带环境中食草动物的季节性体重动态。我们研究了雄性阿尔卑斯山山羊（Capra ibex）体质量季节性变化的长期趋势。我们使用 SEM 检验了体重、体重变化与环境和气候变量之间的直接和间接关系。2000 年至 2022 年期间，我们在意大利大帕拉迪索国家公园对可识别的阿尔卑斯山山羊个体进行了反复称重。在这二十年间，秋季体重大幅增加，某些年龄段的体重增加了 15%。在同一时期，夏季体质量增加和冬季体质量减少，这表明秋季体质量增加是由于几个冬季体质量减少的累积效应。对冬季体重变化影响最大的环境因素是低海拔地区植被返青的起始日期，因为冬季过后，山羊会聚集在那里取食新长出的植被。早春导致冬季体重损失较低，这可能是因为山羊依靠储存脂肪的时间较短，而且有更多的机会获得饲料。高密度的种群也会增加冬季体重损失。因此，环境条件和资源可用性似乎直接影响着雄性阿尔卑斯山山羊的体重动态，而夏季条件的影响似乎较小。通过影响季节性体重动态，气候变化可能会对山区食草动物的生活史和种群动态产生影响，例如，年轻的雄性动物可以更早地进入繁殖期。
{"title":"Climate drives body mass changes in a mountain ungulate: shorter winters lead to heavier Alpine ibex","authors":"Alice Brambilla, Achaz von Hardenberg, Bruno Bassano, Luigi Ranghetti, Lukas Keller, Marco Festa‐Bianchet","doi":"10.1111/oik.10643","DOIUrl":"https://doi.org/10.1111/oik.10643","url":null,"abstract":"Climate affects seasonality and plant phenology, which can influence seasonal body mass dynamics of herbivores in temperate environments. We investigated long‐term trends of seasonal body mass changes in male Alpine ibex <jats:italic>Capra ibex</jats:italic>. We used SEM to test direct and indirect relationships between body mass, mass changes and environmental and climatic variables. Individually recognizable Alpine ibex were weighed repeatedly between 2000 and 2022 in Gran Paradiso National Park (Italy). Autumn mass increased substantially over these two decades, up to 15% in some age classes. Over the same time frame, both summer mass gain and winter mass loss decreased, suggesting that heavier autumn body mass was due to the cumulative effects of reduced mass loss over several winters. The environmental factor with the strongest effects on winter mass changes was the starting date of vegetation green‐up at low altitude, where ibex gather after winter to feed on new growth vegetation. Early springs led to lower winter mass loss, likely because ibex relied on stored fat for a shorter period and had greater access to forage. High population density also increased winter mass loss. Environmental conditions and resource availability, possibly also influenced by density in winter and early spring, seem therefore to directly affect the body mass dynamics of male Alpine ibex, while the effect of summer conditions appears less relevant. By affecting seasonal body mass dynamics, climate change may have consequences for life history and population dynamics of mountain herbivores, for example via earlier access of young males to reproduction.","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"23 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141942454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Global change is a multifaceted, unprecedented crisis hitting the life support system of our planet. Among global changes, climate change is regarded as one of the most grave threats to biodiversity because of its direct impacts on species and ecosystems integrity and because of its indirect consequences through synergistic effects with other global change factors such as biological invasions. The challenges presented to either reduce or mitigate this biodiversity crisis derived from climate change require novel synthesis and innovation in ecological and evolutionary theory. Positive species interactions within and between trophic levels can play a key role in the resilience of ecological communities. Depending on the tolerance of nurse species to different aspects of climate change, communities can be more or less resilient to those changes. This knowledge has important implications for both natural communities and agroecosystems. Further, our fundamental understanding of the role of positive interactions can also enable both effective conservation and restoration levers in space and time.This special issue includes studies addressing the role of facilitative interactions on the response of ecological systems to climate change. Key concepts examined included stress, gradients, nurse species, spatial scale, translocation, phylogenetics alongside physiochemicals, and variation in the capacity of species to buffer changes. Alpine, tundra, drylands and temperate forests were directly tested, but salient principles were relevant to all ecosystems including a contribution on soil biota and also a call to more open data and collaborative science. Together, this corpus of work highlighted the significance of facilitative interactions in mitigating many of the effects of climate change on biodiversity.
{"title":"The importance of facilitative interactions in mediating climate change impact on biodiversity","authors":"Sonia Kéfi, C J. Lortie, Lohengrin A. Cavieres","doi":"10.1111/oik.10984","DOIUrl":"https://doi.org/10.1111/oik.10984","url":null,"abstract":"Global change is a multifaceted, unprecedented crisis hitting the life support system of our planet. Among global changes, climate change is regarded as one of the most grave threats to biodiversity because of its direct impacts on species and ecosystems integrity and because of its indirect consequences through synergistic effects with other global change factors such as biological invasions. The challenges presented to either reduce or mitigate this biodiversity crisis derived from climate change require novel synthesis and innovation in ecological and evolutionary theory. Positive species interactions within and between trophic levels can play a key role in the resilience of ecological communities. Depending on the tolerance of nurse species to different aspects of climate change, communities can be more or less resilient to those changes. This knowledge has important implications for both natural communities and agroecosystems. Further, our fundamental understanding of the role of positive interactions can also enable both effective conservation and restoration levers in space and time.This special issue includes studies addressing the role of facilitative interactions on the response of ecological systems to climate change. Key concepts examined included stress, gradients, nurse species, spatial scale, translocation, phylogenetics alongside physiochemicals, and variation in the capacity of species to buffer changes. Alpine, tundra, drylands and temperate forests were directly tested, but salient principles were relevant to all ecosystems including a contribution on soil biota and also a call to more open data and collaborative science. Together, this corpus of work highlighted the significance of facilitative interactions in mitigating many of the effects of climate change on biodiversity.","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"217 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Tovah D. Siegel, William Justin Cooper, Rebecca E. Forkner, William F. Laurance, José Luís Camargo, David Luther
While many effects of forest fragmentation are reasonably well understood, knowledge of interspecific interactions in fragmented ecosystems is much more limited, particularly for high diversity tropical forests. Using nearly 40 years of data from the Biological Dynamics of Forest Fragments Project in Central Amazonia, we assessed whether forest fragment area and time since isolation impact mutualistic interactions between frugivorous birds and their food resources. We used structural equation modeling to analyze the complex pathways between four main variables determining these interactions: fruiting tree abundance, frugivorous bird abundance, forest fragment area, and time since fragment isolation. Our results confirm that fragment area alters the abundance of some tree resources, with successional plant families increasing in abundance with decreasing fragment size. However, these changes do not drive alterations in the abundance of frugivorous birds. We also tested if bird species with a greater relative diet breadth are less vulnerable to forest fragmentation and found that specialist frugivores are more vulnerable to forest fragmentation immediately after isolation but are not differentially impacted within the long term. Collectively, our results demonstrate the need to further evaluate human‐driven habitat change across multiple timescales to fully understand its impacts on complex species interactions.
{"title":"Forest fragmentation effects on mutualistic interactions: frugivorous birds and fruiting trees","authors":"Tovah D. Siegel, William Justin Cooper, Rebecca E. Forkner, William F. Laurance, José Luís Camargo, David Luther","doi":"10.1111/oik.10383","DOIUrl":"https://doi.org/10.1111/oik.10383","url":null,"abstract":"While many effects of forest fragmentation are reasonably well understood, knowledge of interspecific interactions in fragmented ecosystems is much more limited, particularly for high diversity tropical forests. Using nearly 40 years of data from the Biological Dynamics of Forest Fragments Project in Central Amazonia, we assessed whether forest fragment area and time since isolation impact mutualistic interactions between frugivorous birds and their food resources. We used structural equation modeling to analyze the complex pathways between four main variables determining these interactions: fruiting tree abundance, frugivorous bird abundance, forest fragment area, and time since fragment isolation. Our results confirm that fragment area alters the abundance of some tree resources, with successional plant families increasing in abundance with decreasing fragment size. However, these changes do not drive alterations in the abundance of frugivorous birds. We also tested if bird species with a greater relative diet breadth are less vulnerable to forest fragmentation and found that specialist frugivores are more vulnerable to forest fragmentation immediately after isolation but are not differentially impacted within the long term. Collectively, our results demonstrate the need to further evaluate human‐driven habitat change across multiple timescales to fully understand its impacts on complex species interactions.","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"77 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Federico Morelli, Yanina Benedetti, Dilara Arslan, Juan Delgado
We extensively reviewed scientific literature and extracted a large dataset with roadkill events for reptile species. We examined 300 articles from 33 European countries, gathering 1688 records of reptiles killed by vehicle traffic. A total of 125 taxa were found documented as roadkill (100 native and 25 exotic species). We calculated each species' occurrence frequency within the database (henceforth ‘relative roadkill frequency'). The relative roadkill of species was strongly and significantly correlated when comparing the whole dataset and the subset of systematic studies. We modelled the inter‐specific variation in relative roadkill frequency across the European reptilian phylogeny concerning species traits, evolutionary uniqueness, and distribution range using a phylogenetic generalized least squares (PGLS) model. Overall, reptile casualties are more pronounced for more closely related species. However, the relative roadkill frequency was unrelated to the level of evolutionary distinctiveness of European reptiles. Additionally, relative roadkill frequency was not correlated to the distribution range but was positively correlated with the species' body mass. The reptiles more frequently cited as road casualties were overall relatively large species: Montpellier snake Malpolon monspessulanus, European grass snake Natrix natrix, and Caspian whipsnake Dolichophis caspius. Additionally, more active species during the crepuscular hours were less affected by roadkill. From a conservation point of view, our results suggest that roadkill frequency is not more significant for evolutionary, more unique reptiles than for other species in Europe, while at the same time, widely distributed species are not the main target of roadkill events. Then, the main causes of roadkill in reptiles must be associated with other factors, such as behavioural traits or density of populations, rather than simply the size of their distribution range.Keywords: evolutionary uniqueness, phylogenetic signal, reptile species, roadkill incidence, wildlife conservation
{"title":"Crepuscular and small but not evolutionary unique species are the reptiles less affected by roadkill in Europe","authors":"Federico Morelli, Yanina Benedetti, Dilara Arslan, Juan Delgado","doi":"10.1111/oik.10785","DOIUrl":"https://doi.org/10.1111/oik.10785","url":null,"abstract":"We extensively reviewed scientific literature and extracted a large dataset with roadkill events for reptile species. We examined 300 articles from 33 European countries, gathering 1688 records of reptiles killed by vehicle traffic. A total of 125 taxa were found documented as roadkill (100 native and 25 exotic species). We calculated each species' occurrence frequency within the database (henceforth ‘relative roadkill frequency'). The relative roadkill of species was strongly and significantly correlated when comparing the whole dataset and the subset of systematic studies. We modelled the inter‐specific variation in relative roadkill frequency across the European reptilian phylogeny concerning species traits, evolutionary uniqueness, and distribution range using a phylogenetic generalized least squares (PGLS) model. Overall, reptile casualties are more pronounced for more closely related species. However, the relative roadkill frequency was unrelated to the level of evolutionary distinctiveness of European reptiles. Additionally, relative roadkill frequency was not correlated to the distribution range but was positively correlated with the species' body mass. The reptiles more frequently cited as road casualties were overall relatively large species: Montpellier snake <jats:italic>Malpolon monspessulanus</jats:italic>, European grass snake <jats:italic>Natrix natrix</jats:italic>, and Caspian whipsnake <jats:italic>Dolichophis caspius</jats:italic>. Additionally, more active species during the crepuscular hours were less affected by roadkill. From a conservation point of view, our results suggest that roadkill frequency is not more significant for evolutionary, more unique reptiles than for other species in Europe, while at the same time, widely distributed species are not the main target of roadkill events. Then, the main causes of roadkill in reptiles must be associated with other factors, such as behavioural traits or density of populations, rather than simply the size of their distribution range.Keywords: evolutionary uniqueness, phylogenetic signal, reptile species, roadkill incidence, wildlife conservation","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"51 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
While the positive species–area relationship on islands is frequently observed, the mechanisms underlying this pattern remain poorly studied. By analyzing insular community diversity across spatial scales and the soil properties within the islands, we were able to explore potential mechanisms leading to the island species–area relationship of plants, as well as associated soil bacteria and fungi, from a tropical archipelago. We found that both plant and soil microbial communities showed similar positive species–area relationships across scales and the greater taxonomic diversity on larger islands was mainly driven by the higher richness within samples. These patterns arose primarily due to shifting habitat quality with island area, rather than spatial processes generally attributed to species–area relationships. Specifically, for plants, changes in soil total phosphorus content with island area were most explanatory, while changes in soil pH appeared to play the most important role in shaping soil bacteria and fungi patterns. By contrast, we found little evidence for the role of spatial processes (i.e. dispersal limitation or soil heterogeneity) within the island. Overall, this study highlights the importance of dissecting potential mechanisms underlying multi‐trophic community dynamics to explain patterns of biodiversity and its variation on islands.
{"title":"Habitat quality drives the species–area relationship of plants and soil microbes in an ocean archipelago","authors":"Shurong Zhou, Hao Qin, Renfu Liao, Yikang Cheng","doi":"10.1111/oik.10660","DOIUrl":"https://doi.org/10.1111/oik.10660","url":null,"abstract":"While the positive species–area relationship on islands is frequently observed, the mechanisms underlying this pattern remain poorly studied. By analyzing insular community diversity across spatial scales and the soil properties within the islands, we were able to explore potential mechanisms leading to the island species–area relationship of plants, as well as associated soil bacteria and fungi, from a tropical archipelago. We found that both plant and soil microbial communities showed similar positive species–area relationships across scales and the greater taxonomic diversity on larger islands was mainly driven by the higher richness within samples. These patterns arose primarily due to shifting habitat quality with island area, rather than spatial processes generally attributed to species–area relationships. Specifically, for plants, changes in soil total phosphorus content with island area were most explanatory, while changes in soil pH appeared to play the most important role in shaping soil bacteria and fungi patterns. By contrast, we found little evidence for the role of spatial processes (i.e. dispersal limitation or soil heterogeneity) within the island. Overall, this study highlights the importance of dissecting potential mechanisms underlying multi‐trophic community dynamics to explain patterns of biodiversity and its variation on islands.","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"60 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Ciro Cabal, Fernando Valladares, Stephen W. Pacala
Shrubs are usually adapted to stressful environments in which soil resources are limited, and thus, roots are fundamental for their biological success. However, root measures are challenging to collect, especially in field conditions and at the individual level. For this study, we collected data on the three‐dimensional distribution of fine root biomass of twenty‐three individuals belonging to three shrub species in a mediterranean shrubland in central Spain: gum rockrose Cistus ladanifer, rosemary Salvia rosmarinus, and hairy‐fruited broom Cytisus striatus. Our goal was to determine the soil‐foraging strategies adopted by the plants. We hypothesized that plants would show stabilizing niche differences explaining the high plant biodiversity characteristic of mediterranean shrublands and that they would follow the game theory model's prediction of exploitative segregation of roots behaving territorially but also over‐proliferating roots close to their stem and engaging in a root tragedy of the commons. We found that two‐thirds to three‐fourths of the biomass was belowground, and the system's productivity was roughly 500–600 g C m−2 year−1. Only rosemary plants competed with neighbors following the exploitative segregation predictions. Broom plants had the shallowest and most widespread root systems but significantly reduced their root range toward competing neighbors. Gum rockrose presented deep, narrow root systems avoiding extensive overlap with neighbors but did not appear to respond to competitive pressure levels. Shrubs appeared to stratify their roots at different soil depths, supporting the niche segregation hypothesis.
灌木通常适应土壤资源有限的压力环境，因此根系是其生物成功的基础。然而，根的测量数据很难收集，尤其是在野外条件下和个体水平上。在这项研究中，我们收集了西班牙中部地中海灌木林中三种灌木物种的 23 个个体的细根生物量的三维分布数据，这三种灌木物种分别是：岩蔷薇 Cistus ladanifer、迷迭香 Salvia rosmarinus 和毛果扫帚 Cytisus striatus。我们的目标是确定植物采用的觅土策略。我们假设，植物会表现出稳定的生态位差异，以解释地中海灌木地植物生物多样性高的特点，并假设它们会遵循博弈论模型的预测，即根系的开发性隔离行为具有领地性，但也会在靠近茎干的地方过度增殖根系，上演根系的公地悲剧。我们发现，三分之二到四分之三的生物量在地下，系统的生产力大约为每年 500-600 克 C m-2。只有迷迭香植物与邻居的竞争符合开发性隔离的预测。扫帚属植物的根系最浅、分布最广，但它们的根系范围明显缩小，与竞争邻居的根系范围相近。岩蔷薇的根系深而窄，避免了与邻居的广泛重叠，但似乎对竞争压力水平没有反应。灌木似乎在不同的土壤深度对根系进行分层，这支持了生态位隔离假说。
{"title":"Root foraging strategies and niche segregation of three mediterranean shrub species","authors":"Ciro Cabal, Fernando Valladares, Stephen W. Pacala","doi":"10.1111/oik.10724","DOIUrl":"https://doi.org/10.1111/oik.10724","url":null,"abstract":"Shrubs are usually adapted to stressful environments in which soil resources are limited, and thus, roots are fundamental for their biological success. However, root measures are challenging to collect, especially in field conditions and at the individual level. For this study, we collected data on the three‐dimensional distribution of fine root biomass of twenty‐three individuals belonging to three shrub species in a mediterranean shrubland in central Spain: gum rockrose <jats:italic>Cistus ladanifer</jats:italic>, rosemary <jats:italic>Salvia rosmarinus</jats:italic>, and hairy‐fruited broom <jats:italic>Cytisus striatus</jats:italic>. Our goal was to determine the soil‐foraging strategies adopted by the plants. We hypothesized that plants would show stabilizing niche differences explaining the high plant biodiversity characteristic of mediterranean shrublands and that they would follow the game theory model's prediction of exploitative segregation of roots behaving territorially but also over‐proliferating roots close to their stem and engaging in a root tragedy of the commons. We found that two‐thirds to three‐fourths of the biomass was belowground, and the system's productivity was roughly 500–600 g C m<jats:sup>−2</jats:sup> year<jats:sup>−1</jats:sup>. Only rosemary plants competed with neighbors following the exploitative segregation predictions. Broom plants had the shallowest and most widespread root systems but significantly reduced their root range toward competing neighbors. Gum rockrose presented deep, narrow root systems avoiding extensive overlap with neighbors but did not appear to respond to competitive pressure levels. Shrubs appeared to stratify their roots at different soil depths, supporting the niche segregation hypothesis.","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"37 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Marketa Zimova, Scott Newey, Becks Denny, Simen Pedersen, L. Scott Mills
Climate change has resulted in a myriad of stressors to wild organisms. Phenotypic plasticity, including behavioral plasticity, is hypothesized to play a key role in allowing animals to cope with rapid climate change and mitigate its negative fitness consequences. Camouflage mismatch resulting from decreasing duration of snow cover presents a stressor to species that undergo coat color molts to maintain camouflage against seasonally changing backgrounds. Winter white animals appear highly conspicuous against dark, snowless background and experience increased predation‐induced mortality. Here, we evaluate the potential of behavioral plasticity to buffer against camouflage mismatch in mountain hares Lepus timidus in Scotland. We carried out field surveys in three populations over two years and found no evidence that hares modify their behaviors in response to increasing camouflage mismatch. Hares did not prefer to rest closer to light‐colored rocks or farther from conspecifics with increasing color contrast. Furthermore, whiter hares did not seek to rest closer to snowy backgrounds; rather, hares preferred to sit farther from snow. These results suggest that behavioral plasticity might not be a universal, rapid mechanism facilitating adaptation to climate change.Keywords: behavioral plasticity, camouflage, climate change, mountain hares, phenological mismatch
{"title":"Scottish mountain hares do not respond behaviorally to camouflage mismatch","authors":"Marketa Zimova, Scott Newey, Becks Denny, Simen Pedersen, L. Scott Mills","doi":"10.1111/oik.10834","DOIUrl":"https://doi.org/10.1111/oik.10834","url":null,"abstract":"Climate change has resulted in a myriad of stressors to wild organisms. Phenotypic plasticity, including behavioral plasticity, is hypothesized to play a key role in allowing animals to cope with rapid climate change and mitigate its negative fitness consequences. Camouflage mismatch resulting from decreasing duration of snow cover presents a stressor to species that undergo coat color molts to maintain camouflage against seasonally changing backgrounds. Winter white animals appear highly conspicuous against dark, snowless background and experience increased predation‐induced mortality. Here, we evaluate the potential of behavioral plasticity to buffer against camouflage mismatch in mountain hares <jats:italic>Lepus timidus</jats:italic> in Scotland. We carried out field surveys in three populations over two years and found no evidence that hares modify their behaviors in response to increasing camouflage mismatch. Hares did not prefer to rest closer to light‐colored rocks or farther from conspecifics with increasing color contrast. Furthermore, whiter hares did not seek to rest closer to snowy backgrounds; rather, hares preferred to sit farther from snow. These results suggest that behavioral plasticity might not be a universal, rapid mechanism facilitating adaptation to climate change.Keywords: behavioral plasticity, camouflage, climate change, mountain hares, phenological mismatch","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"30 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Merijn Moens, Jacobus C. Biesmeijer, Elaine Huang, Nicolas J. Vereecken, Leon Marshall
Studies have found that biotic information can play an important role in shaping the distribution of species even at large scales. However, results from species distribution models are not always consistent among studies and the underlying factors that influence the importance of biotic information to distribution models, are unclear. We studied wild bees and plants, and cleptoparasite bees and their hosts in the Netherlands to evaluate how the inclusion of their biotic interactions affects the performance of species distribution models. We assessed model performance through spatial block cross‐validation and by comparing models with interactions to models where the interacting species was randomized. Finally, we evaluated how, 1) spatial resolution, 2) taxonomic rank (genus or species), 3) degree of specialization, 4) distribution of the biotic factor, 5) bee body size and 6) type of biotic interaction, affect the importance of biotic interactions in shaping the distribution of wild bee species using generalized linear models (GLMs). We found that the models of wild bees improved when the biotic factor was included. The model performance improved the most for parasitic bees. Spatial resolution, taxonomic rank, distribution range of the biotic factor and degree of specialization of the modelled species all influenced the importance of the biotic interaction to the models. We encourage researchers to include biotic interactions in species distribution models, especially for specialized species and when the biotic factor has a limited distribution range. However, before adding the biotic factor we suggest considering different spatial resolutions and taxonomic ranks of the biotic factor. We recommend using single species or genus data as a biotic factor in the models of specialist species and for the generalist species, we recommend using an approximate measure of interactions, such as flower richness.
{"title":"The importance of biotic interactions in distribution models of wild bees depends on the type of ecological relations, spatial scale and range","authors":"Merijn Moens, Jacobus C. Biesmeijer, Elaine Huang, Nicolas J. Vereecken, Leon Marshall","doi":"10.1111/oik.10578","DOIUrl":"https://doi.org/10.1111/oik.10578","url":null,"abstract":"Studies have found that biotic information can play an important role in shaping the distribution of species even at large scales. However, results from species distribution models are not always consistent among studies and the underlying factors that influence the importance of biotic information to distribution models, are unclear. We studied wild bees and plants, and cleptoparasite bees and their hosts in the Netherlands to evaluate how the inclusion of their biotic interactions affects the performance of species distribution models. We assessed model performance through spatial block cross‐validation and by comparing models with interactions to models where the interacting species was randomized. Finally, we evaluated how, 1) spatial resolution, 2) taxonomic rank (genus or species), 3) degree of specialization, 4) distribution of the biotic factor, 5) bee body size and 6) type of biotic interaction, affect the importance of biotic interactions in shaping the distribution of wild bee species using generalized linear models (GLMs). We found that the models of wild bees improved when the biotic factor was included. The model performance improved the most for parasitic bees. Spatial resolution, taxonomic rank, distribution range of the biotic factor and degree of specialization of the modelled species all influenced the importance of the biotic interaction to the models. We encourage researchers to include biotic interactions in species distribution models, especially for specialized species and when the biotic factor has a limited distribution range. However, before adding the biotic factor we suggest considering different spatial resolutions and taxonomic ranks of the biotic factor. We recommend using single species or genus data as a biotic factor in the models of specialist species and for the generalist species, we recommend using an approximate measure of interactions, such as flower richness.","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"66 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Eve B. Cooper, Lauren J. N. Brent, Noah Snyder‐Mackler, James P. Higham
The life‐history tradeoff between reproduction and survival often results in a discordant timing of peak mortality risk for males and females in seasonally reproducing species. Understanding how this seasonal association between reproductive investment and survival is impacted by individual age, demography, and climate is increasingly important as anthropogenic influence is driving rapid global climate and population structure changes. We investigate how tradeoffs between seasonal reproductive investment and survival have fluctuated in response to observed changes in demography and climate using 60 years of demographic records collected from a free‐ranging population of rhesus macaques Macaca mulatta (n = 1919 males, 1609 females). Seasonal mortality rates fluctuated significantly over the 60‐year period for both males and females. In males, but not females, age‐specific survival was different during periods of low and high reproductive investment, indicating that tradeoffs between reproduction and survival are particularly age‐dependent in males. There was no little to no evidence for an effect of sex ratio on survival in either sex. In both sexes, higher population density was associated with lower survival, and this negative effect of density was particularly strong during each sex's period of low reproductive investment. While there was no evidence for an effect of temperature on female survival during periods of low reproductive investment, during periods of high reproductive investment there was a positive association between average daily temperature maximum and female survival. Female survival was higher overall when rainfall was greater, and this positive effect of rainfall on survival was particularly strong for females during periods of low reproductive investment. Conversely, there were no effects of temperature or rainfall on male survival. The results of this study illustrate the considerable ways that climatic and demographic factors can influence sex‐specific mortality during each sex's distinct periods of reproductive investment.
{"title":"Demography and climate influence sex‐specific survival costs of reproduction over 60 years in a free ranging primate population","authors":"Eve B. Cooper, Lauren J. N. Brent, Noah Snyder‐Mackler, James P. Higham","doi":"10.1111/oik.10624","DOIUrl":"https://doi.org/10.1111/oik.10624","url":null,"abstract":"The life‐history tradeoff between reproduction and survival often results in a discordant timing of peak mortality risk for males and females in seasonally reproducing species. Understanding how this seasonal association between reproductive investment and survival is impacted by individual age, demography, and climate is increasingly important as anthropogenic influence is driving rapid global climate and population structure changes. We investigate how tradeoffs between seasonal reproductive investment and survival have fluctuated in response to observed changes in demography and climate using 60 years of demographic records collected from a free‐ranging population of rhesus macaques <jats:italic>Macaca mulatta</jats:italic> (n = 1919 males, 1609 females). Seasonal mortality rates fluctuated significantly over the 60‐year period for both males and females. In males, but not females, age‐specific survival was different during periods of low and high reproductive investment, indicating that tradeoffs between reproduction and survival are particularly age‐dependent in males. There was no little to no evidence for an effect of sex ratio on survival in either sex. In both sexes, higher population density was associated with lower survival, and this negative effect of density was particularly strong during each sex's period of low reproductive investment. While there was no evidence for an effect of temperature on female survival during periods of low reproductive investment, during periods of high reproductive investment there was a positive association between average daily temperature maximum and female survival. Female survival was higher overall when rainfall was greater, and this positive effect of rainfall on survival was particularly strong for females during periods of low reproductive investment. Conversely, there were no effects of temperature or rainfall on male survival. The results of this study illustrate the considerable ways that climatic and demographic factors can influence sex‐specific mortality during each sex's distinct periods of reproductive investment.","PeriodicalId":19496,"journal":{"name":"Oikos","volume":"97 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141739833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
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