Tropical forest biodiversity is under immense pressure due to a combination of global and local factors, including climate change and intensive land use. Birds play an important role in tropical forest ecosystems, contributing significantly to various ecosystem services. This study examined the impact of deforestation on the richness and abundance of understorey-nesting bird communities along a land-use intensification gradient in the peripheral zone of Korup National Park, Southwest Cameroon. We selected 30 sampling plots, each covering 4 ha, across five habitat types: near-primary forest, secondary forest, disturbed forest, cocoa/coffee plantations, and annual food crop fields. A total of 236 understorey bird nests were identified, representing 16 species. Our findings revealed that land use intensity significantly influenced bird species richness and abundance. Primary and secondary forests provided 75% of the nesting species and 71% of the nests. However, 19% of the species either appeared or increased in cocoa/coffee plantations and annual crop fields. Among the feeding groups, frugivores were the most sensitive group to deforestation. This study corroborates the adverse effects of forest destruction on birds communities and highlights the urgent need to address the rapid and extensive forest conversion occurring within Korup National Park. Allowing secondary forests to regenerate and preserving large patches of primary forest are essential strategies to help understorey-nesting bird communities mitigate the impacts of global changes.
{"title":"Understorey-nesting bird community responses to land use in the Korup National Park, an Afrotropical rainforest in South-Western Cameroon","authors":"Jean Tonleu , Noelline Tsafack , Kadiri S. Bobo , Sebastien Lhoumeau , Wilfried G.T. Lontchi , Cyrille L.T. Tanebang , Mpoame Mbida","doi":"10.1016/j.actao.2024.104040","DOIUrl":"10.1016/j.actao.2024.104040","url":null,"abstract":"<div><div>Tropical forest biodiversity is under immense pressure due to a combination of global and local factors, including climate change and intensive land use. Birds play an important role in tropical forest ecosystems, contributing significantly to various ecosystem services. This study examined the impact of deforestation on the richness and abundance of understorey-nesting bird communities along a land-use intensification gradient in the peripheral zone of Korup National Park, Southwest Cameroon. We selected 30 sampling plots, each covering 4 ha, across five habitat types: near-primary forest, secondary forest, disturbed forest, cocoa/coffee plantations, and annual food crop fields. A total of 236 understorey bird nests were identified, representing 16 species. Our findings revealed that land use intensity significantly influenced bird species richness and abundance. Primary and secondary forests provided 75% of the nesting species and 71% of the nests. However, 19% of the species either appeared or increased in cocoa/coffee plantations and annual crop fields. Among the feeding groups, frugivores were the most sensitive group to deforestation. This study corroborates the adverse effects of forest destruction on birds communities and highlights the urgent need to address the rapid and extensive forest conversion occurring within Korup National Park. Allowing secondary forests to regenerate and preserving large patches of primary forest are essential strategies to help understorey-nesting bird communities mitigate the impacts of global changes.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104040"},"PeriodicalIF":1.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-11-21DOI: 10.1016/j.actao.2024.104038
Rodrigo Gómez Alés , Franco Valdez Ovallez , Oscar A. Stellatelli , Ana E. Victorica Erostarbe , Rodrigo Nieva Cocilio , Ana P. Galdeano , Graciela M. Blanco , Juan Carlos Acosta
Lizard assemblages are dynamic, influenced by both seasonal climatic changes and intrinsic population shifts. Climate plays a crucial role in shaping lizard phenology, or the timing of their biological events, which critically affects the spatiotemporal structure of sympatric populations. Understanding how species richness and abundance fluctuate over time, and how these changes are influences by temporal factors, is essential for distinguishing between variations caused by unpredictable external factors and underlying natural changes. This study aimed to characterize lizard assemblage structure and dynamics, as well as species demographics, over three consecutive years within an Arid Chaco - Monte ecotone in central-western Argentina. We also sought to assess the effects of environmental drivers (e.g., temperature, precipitation) on assemblage and population dynamics. Monthly samples were taken using pitfall traps from October 2015 to May 2018 within the protected area of the Valle Fértil Multiple Use Reserve. We captured 1446 lizards, representing 12 species. Liolaemus chacoensis was dominant in the assemblage, followed by Teius teyou and Aurivela longicauda. Species richness and diversity varied seasonally, peaking during summer and autumn. The lizard assemblage exhibited activity throughout all seasons, with significant temporal niche overlap between species. Reproduction and activity in lizards were highly seasonal, primarily occurring in spring and summer, likely due to low winter temperatures and highly seasonal rainfall. Our study shows that climate seasonality and the demographics of the dominant species significantly influence the temporal dynamics of lizard assemblages in the Arid Chaco-Monte ecotone of Argentina.
{"title":"Climatic seasonality and dominant species drive the temporal dynamics in a lizard assemblage in the Arid Chaco - Monte ecotone","authors":"Rodrigo Gómez Alés , Franco Valdez Ovallez , Oscar A. Stellatelli , Ana E. Victorica Erostarbe , Rodrigo Nieva Cocilio , Ana P. Galdeano , Graciela M. Blanco , Juan Carlos Acosta","doi":"10.1016/j.actao.2024.104038","DOIUrl":"10.1016/j.actao.2024.104038","url":null,"abstract":"<div><div>Lizard assemblages are dynamic, influenced by both seasonal climatic changes and intrinsic population shifts. Climate plays a crucial role in shaping lizard phenology, or the timing of their biological events, which critically affects the spatiotemporal structure of sympatric populations. Understanding how species richness and abundance fluctuate over time, and how these changes are influences by temporal factors, is essential for distinguishing between variations caused by unpredictable external factors and underlying natural changes. This study aimed to characterize lizard assemblage structure and dynamics, as well as species demographics, over three consecutive years within an Arid Chaco - Monte ecotone in central-western Argentina. We also sought to assess the effects of environmental drivers (e.g., temperature, precipitation) on assemblage and population dynamics. Monthly samples were taken using pitfall traps from October 2015 to May 2018 within the protected area of the Valle Fértil Multiple Use Reserve. We captured 1446 lizards, representing 12 species. <em>Liolaemus chacoensis</em> was dominant in the assemblage, followed by <em>Teius teyou</em> and <em>Aurivela longicauda</em>. Species richness and diversity varied seasonally, peaking during summer and autumn. The lizard assemblage exhibited activity throughout all seasons, with significant temporal niche overlap between species. Reproduction and activity in lizards were highly seasonal, primarily occurring in spring and summer, likely due to low winter temperatures and highly seasonal rainfall. Our study shows that climate seasonality and the demographics of the dominant species significantly influence the temporal dynamics of lizard assemblages in the Arid Chaco-Monte ecotone of Argentina.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104038"},"PeriodicalIF":1.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-11-21DOI: 10.1016/j.actao.2024.104042
Said Mohammed , Klaus Mummenhoff
The aim of this study was to compare the role of mucilage in seed dispersal and germination of the two closely related invasive weed species, Lepidium campestre and Lepidium draba. The study investigated the staining patterns of mucilage and its effects on seed germination, water uptake, dehydration, adherence to sand particles and dispersal by wind, water and animals following standard protocols. The mucilaginous seeds of L. campestre had a higher pectin and cellulose content than L. draba. This difference has a significant effect on water uptake and retention. The mucilage increased water uptake in both species, with L. campestre seeds absorbing significantly more water (836% compared to 75% in L. draba). Remarkably, the mucilage of both species had very little effect on seed germination. Significantly, the seeds of L. draba readily germinated under dry conditions, suggesting that this species may have developed different germination strategies. In addition, the seeds and fruits of L. draba showed a higher potential for dispersal via water and wind, whereas those of L. campestre adhered to animals. Further, L. campestre seeds showed significantly stronger adherence to sand particles (1872%) compared to those of L. draba (445%). This suggests that L. campestre seeds are more likely to disperse locally and possibly adhere to animals or soil particles. Our results suggest that mucilage produce by the two invasive weed species results in different methods of dispersal, which may help explain differences in their distribution patterns.
本研究的目的是比较粘液质在两种亲缘关系很近的入侵杂草--野营鹅掌楸（Lepidium campestre）和垂叶鹅掌楸（Lepidium draba）--的种子传播和萌发中的作用。研究按照标准方案调查了粘液的染色模式及其对种子萌发、吸水、脱水、附着在沙粒上以及通过风、水和动物散播的影响。L. campestre 的粘液种子果胶和纤维素含量高于 L. draba。这种差异对吸水和保水有很大影响。粘液增加了这两个物种的吸水率，其中 L. campestre 种子的吸水率明显更高（836%，而 L. draba 为 75%）。值得注意的是，两种植物的粘液对种子萌发的影响都很小。值得注意的是，L. draba 的种子在干燥条件下很容易萌发，这表明该物种可能已经形成了不同的萌发策略。此外，L. draba 的种子和果实通过水和风传播的可能性更大，而 L. campestre 的种子和果实则会粘附在动物身上。此外，L. campestre 种子对沙粒的附着力（1872%）明显强于 L. draba 种子（445%）。这表明，L. campestre 种子更有可能在当地扩散，并有可能粘附在动物或土壤颗粒上。我们的研究结果表明，这两种入侵杂草产生的粘液导致了不同的传播方式，这可能有助于解释它们分布模式的差异。
{"title":"Functional divergence exists in mucilage-mediated seed dispersal, but not in germination of myxospermic Lepidium campestre and Lepidium draba (Brassicaceae)","authors":"Said Mohammed , Klaus Mummenhoff","doi":"10.1016/j.actao.2024.104042","DOIUrl":"10.1016/j.actao.2024.104042","url":null,"abstract":"<div><div>The aim of this study was to compare the role of mucilage in seed dispersal and germination of the two closely related invasive weed species, <em>Lepidium campestre</em> and <em>Lepidium draba</em>. The study investigated the staining patterns of mucilage and its effects on seed germination, water uptake, dehydration, adherence to sand particles and dispersal by wind, water and animals following standard protocols. The mucilaginous seeds of <em>L. campestre</em> had a higher pectin and cellulose content than <em>L. draba</em>. This difference has a significant effect on water uptake and retention. The mucilage increased water uptake in both species, with <em>L. campestre</em> seeds absorbing significantly more water (836% compared to 75% in <em>L. draba</em>). Remarkably, the mucilage of both species had very little effect on seed germination. Significantly, the seeds of <em>L. draba</em> readily germinated under dry conditions, suggesting that this species may have developed different germination strategies. In addition, the seeds and fruits of <em>L. draba</em> showed a higher potential for dispersal via water and wind, whereas those of <em>L. campestre</em> adhered to animals. Further, <em>L. campestre</em> seeds showed significantly stronger adherence to sand particles (1872%) compared to those of <em>L. draba</em> (445%). This suggests that <em>L. campestre</em> seeds are more likely to disperse locally and possibly adhere to animals or soil particles. Our results suggest that mucilage produce by the two invasive weed species results in different methods of dispersal, which may help explain differences in their distribution patterns.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104042"},"PeriodicalIF":1.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-10-20DOI: 10.1016/j.actao.2024.104037
Christian Damgaard, Jesper Leth Bak, Morten Strandberg, Rikke Reisner Hansen
Ecosystem stability and resilience are vital characteristics for understanding key ecosystem dynamics, conservation management and restoration issues. However, for heathlands and other semi-natural ecosystems investigating stability and resilience demands a different approach from that of more stable ecosystems closer to a successional climax state, since we need to distinguish between 1) disturbances that are needed to maintain the ecosystem in a habitat-characteristic state, and 2) pressures that may perturb the ecosystem away from a characteristic state. Here, we suggest methods to measure and predict resilience in Atlantic dry heathland ecosystems. This will be achieved by outlining a working hypothesis of the most important factors that regulate the stability and resilience of semi-natural heathland ecosystems. At the center of the proposed hypothesis is the amount of nitrogen in the soil that is available for plant growth and how the nitrogen-cycling pathway is formed by dominant species of heathland ecosystems. Furthermore, we will discuss possible ways to quantify semi-natural ecosystem resilience and suggest a research program that would allow us to test the outlined working hypothesis in semi-natural ecosystems and provide quantitative information for making ecological predictions on heathland stability and resilience. This investigation has direct consequences for how heathland conservation may be planned in a way that protects both resilience, structure, function and the characteristic species of heathlands. It could also form an ecological basis for investigating anthropogenic practices and ways to protect its associated culture-historical values.
{"title":"The resilience of heathland ecosystems: A working hypothesis","authors":"Christian Damgaard, Jesper Leth Bak, Morten Strandberg, Rikke Reisner Hansen","doi":"10.1016/j.actao.2024.104037","DOIUrl":"10.1016/j.actao.2024.104037","url":null,"abstract":"<div><div>Ecosystem stability and resilience are vital characteristics for understanding key ecosystem dynamics, conservation management and restoration issues. However, for heathlands and other semi-natural ecosystems investigating stability and resilience demands a different approach from that of more stable ecosystems closer to a successional climax state, since we need to distinguish between 1) <em>disturbances</em> that are needed to maintain the ecosystem in a habitat-characteristic state, and 2) <em>pressures</em> that may perturb the ecosystem away from a characteristic state. Here, we suggest methods to measure and predict resilience in Atlantic dry heathland ecosystems. This will be achieved by outlining a working hypothesis of the most important factors that regulate the stability and resilience of semi-natural heathland ecosystems. At the center of the proposed hypothesis is the amount of nitrogen in the soil that is available for plant growth and how the nitrogen-cycling pathway is formed by dominant species of heathland ecosystems. Furthermore, we will discuss possible ways to quantify semi-natural ecosystem resilience and suggest a research program that would allow us to test the outlined working hypothesis in semi-natural ecosystems and provide quantitative information for making ecological predictions on heathland stability and resilience. This investigation has direct consequences for how heathland conservation may be planned in a way that protects both resilience, structure, function and the characteristic species of heathlands. It could also form an ecological basis for investigating anthropogenic practices and ways to protect its associated culture-historical values.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104037"},"PeriodicalIF":1.3,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-10-19DOI: 10.1016/j.actao.2024.104036
Rafael Costa Cardoso, Rodrigo Lopes Ferreira, Marconi Souza-Silva
Caves, once thought to be isolated ecosystems", are now understood to have intricate connections with surface environments, particularly evident at their entrances. These connections can significantly affect the microclimate within caves, leading to varying degrees of environmental stability. Our research explores the impact of microclimate conditions, specifically related to cave environmental stability, on biodiversity changes. We surveyed subterranean invertebrates during two different seasonal periods in 17 limestone caves in three karst regions in southeastern Brazil. Our analysis aimed to understand how environmental stability influences the overall richness of cave invertebrates and troglobitic species richness (restricted to subterranean habitats). We hypothesized that more stable caves would experience less fluctuation in relative species richness and lower turnover between seasons. Additionally, we anticipated that caves with greater environmental stability would harbor a higher richness of cave-restricted species in the function of their length. Our findings support these hypotheses, revealing a significant positive correlation between cave environmental stability and species richness. Caves with higher environmental stability demonstrated lower species turnover rates between seasons, indicating enhanced community stability. While environmental stability significantly affected species richness, its influence on cave-restricted species was comparatively less pronounced. This suggests a complex interplay of factors shaping the unique fauna of caves. Nonetheless, the implications of climate change underscore the importance of preserving the environmental stability of these ecosystems. Using environmental stability as a guide can help protect cave biodiversity from the adverse effects of climate change, contributing to broader conservation efforts for these unique habitats.
{"title":"Caves’ environmental stability shaping subterranean biodiversity in the neotropics","authors":"Rafael Costa Cardoso, Rodrigo Lopes Ferreira, Marconi Souza-Silva","doi":"10.1016/j.actao.2024.104036","DOIUrl":"10.1016/j.actao.2024.104036","url":null,"abstract":"<div><div>Caves, once thought to be isolated ecosystems\", are now understood to have intricate connections with surface environments, particularly evident at their entrances. These connections can significantly affect the microclimate within caves, leading to varying degrees of environmental stability. Our research explores the impact of microclimate conditions, specifically related to cave environmental stability, on biodiversity changes. We surveyed subterranean invertebrates during two different seasonal periods in 17 limestone caves in three karst regions in southeastern Brazil. Our analysis aimed to understand how environmental stability influences the overall richness of cave invertebrates and troglobitic species richness (restricted to subterranean habitats). We hypothesized that more stable caves would experience less fluctuation in relative species richness and lower turnover between seasons. Additionally, we anticipated that caves with greater environmental stability would harbor a higher richness of cave-restricted species in the function of their length. Our findings support these hypotheses, revealing a significant positive correlation between cave environmental stability and species richness. Caves with higher environmental stability demonstrated lower species turnover rates between seasons, indicating enhanced community stability. While environmental stability significantly affected species richness, its influence on cave-restricted species was comparatively less pronounced. This suggests a complex interplay of factors shaping the unique fauna of caves. Nonetheless, the implications of climate change underscore the importance of preserving the environmental stability of these ecosystems. Using environmental stability as a guide can help protect cave biodiversity from the adverse effects of climate change, contributing to broader conservation efforts for these unique habitats.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104036"},"PeriodicalIF":1.3,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-10-18DOI: 10.1016/j.actao.2024.104035
Marcelo H. Cassini, Luciano Rivas
Species that have been introduced into regions outside their native range can damage biodiversity and natural ecosystems. Hyperpredation is the process by which an introduced primary prey enables a generalist predator to increase dramatically in numbers leading to sustained abnormally high predation of secondary native prey. Testing the hyperpredation model is a challenging task because it has several assumptions but no exclusive predictions that are inconsistent with alternative hypotheses, for which data supporting several predictions are required to validate this hypothesis. We reviewed studies that postulate hyperpredation as a mechanism explaining the impact of introduced species. We used Scopus and Google Scholar databases for finding publications and Prisma protocol for selecting them. No one of the 44 selected publications provided enough information to demonstrate hyperpredation as the mechanism responsible for the impact of introduced prey populations on native biodiversity because (i) in all studies there were other ecological mechanisms that could explain the observed decline of native prey; (ii) no study have considered all the assumptions of the hyperpredation model, nor found positive results for all its predictions, and (iii) most studies used observational, descriptive method instead of field experiments that explicitly try to refute alternative hypotheses.
引入原生地以外地区的物种会破坏生物多样性和自然生态系统。过度捕食是指引入的主要猎物使通性捕食者的数量急剧增加，导致对次要本地猎物的捕食量持续异常增加的过程。检验超捕食模型是一项具有挑战性的任务，因为它有几个假设，但没有与其他假设不一致的独家预测，因此需要支持几个预测的数据来验证这一假设。我们回顾了将超捕食假定为解释引入物种影响机制的研究。我们使用 Scopus 和 Google Scholar 数据库查找出版物，并使用 Prisma 协议筛选出版物。在所选的 44 篇出版物中，没有一篇提供了足够的信息来证明超捕食是引入猎物种群对本地生物多样性造成影响的机制，因为（i）在所有研究中，还有其他生态机制可以解释所观察到的本地猎物的减少；（ii）没有一项研究考虑了超捕食模型的所有假设，也没有发现其所有预测的积极结果；（iii）大多数研究使用了观察和描述性方法，而不是明确尝试反驳其他假设的野外实验。
{"title":"Hyperpredation as a mechanism responsible for the impact of introduced populations on native biodiversity","authors":"Marcelo H. Cassini, Luciano Rivas","doi":"10.1016/j.actao.2024.104035","DOIUrl":"10.1016/j.actao.2024.104035","url":null,"abstract":"<div><div>Species that have been introduced into regions outside their native range can damage biodiversity and natural ecosystems. Hyperpredation is the process by which an introduced primary prey enables a generalist predator to increase dramatically in numbers leading to sustained abnormally high predation of secondary native prey. Testing the hyperpredation model is a challenging task because it has several assumptions but no exclusive predictions that are inconsistent with alternative hypotheses, for which data supporting several predictions are required to validate this hypothesis. We reviewed studies that postulate hyperpredation as a mechanism explaining the impact of introduced species. We used Scopus and Google Scholar databases for finding publications and Prisma protocol for selecting them. No one of the 44 selected publications provided enough information to demonstrate hyperpredation as the mechanism responsible for the impact of introduced prey populations on native biodiversity because (i) in all studies there were other ecological mechanisms that could explain the observed decline of native prey; (ii) no study have considered all the assumptions of the hyperpredation model, nor found positive results for all its predictions, and (iii) most studies used observational, descriptive method instead of field experiments that explicitly try to refute alternative hypotheses.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104035"},"PeriodicalIF":1.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-09-27DOI: 10.1016/j.actao.2024.104031
Kohei Nakatsuji , Yuta Kobayashi , Tomohiro Yoshida
Predation plays an important role in the coexistence of multiple species within forest ecosystems. It is spatially heterogeneous and influenced by the surrounding environment at different spatial scales. Studies focusing on multiple environmental factors in systems with high spatial complexity are lacking, but elucidating the effects of local environmental factors within a forest could assist in understanding the effects of local differences in predation pressures on multispecies coexistence. Here, we examined the effects of microtopography and vegetation on predation pressure using the model caterpillar method. We hypothesized that differences in microtopography and vegetation types would result in different predation pressures on invertebrates within a forest. Insect attacks were dominant throughout the study period. The attack rates on the model caterpillars were also lower on hill tops and evergreen deciduous trees. Predation pressure within the forest was heterogeneous and independently influenced by topography and vegetation type. Our results suggest that environmental heterogeneity within forests may lead to highly variable predation pressures and affect multispecies coexistence. This study suggests that microtopography and vegetation types within forests should be considered for biological control.
{"title":"Microtopography and vegetation generate uneven predation pressure on forest insects","authors":"Kohei Nakatsuji , Yuta Kobayashi , Tomohiro Yoshida","doi":"10.1016/j.actao.2024.104031","DOIUrl":"10.1016/j.actao.2024.104031","url":null,"abstract":"<div><div>Predation plays an important role in the coexistence of multiple species within forest ecosystems. It is spatially heterogeneous and influenced by the surrounding environment at different spatial scales. Studies focusing on multiple environmental factors in systems with high spatial complexity are lacking, but elucidating the effects of local environmental factors within a forest could assist in understanding the effects of local differences in predation pressures on multispecies coexistence. Here, we examined the effects of microtopography and vegetation on predation pressure using the model caterpillar method. We hypothesized that differences in microtopography and vegetation types would result in different predation pressures on invertebrates within a forest. Insect attacks were dominant throughout the study period. The attack rates on the model caterpillars were also lower on hill tops and evergreen deciduous trees. Predation pressure within the forest was heterogeneous and independently influenced by topography and vegetation type. Our results suggest that environmental heterogeneity within forests may lead to highly variable predation pressures and affect multispecies coexistence. This study suggests that microtopography and vegetation types within forests should be considered for biological control.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104031"},"PeriodicalIF":1.3,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-09-26DOI: 10.1016/j.actao.2024.104030
Amelia S.N. Kumala, Devi N. Choesin, Ichsan Suwandhi
The seagrass ecosystem is considered one of the most effective coastal ecosystems in storing carbon. Carbon stock estimation for a certain ecosystem is highly affected by factors such as species diversity and habitat type. This study aims to investigate the relationship between plant community structure and carbon stocks in the seagrass ecosystem using a case study of six coastal sites in Karimunjawa Marine National Park, Indonesia. In this region, eight seagrass species were recorded, i.e., Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Halodule pinifolia, Halophila ovalis, Halophila minor, Syringodium isoetifolium, and Oceana serrulata. From the six study sites, the highest estimated carbon stock was 426.2 Mg C ha−1 (Site 5; Telaga, dominated by E. acoroides). Meanwhile, the lowest estimated carbon stock was 127.4 Mg C ha−1 (Site 4; Koin, dominated by T. hemprichii). The density of E. acoroides was positively correlated with the total seagrass biomass carbon stocks (r = 0.97; p < 0.01), while its dominance was positively correlated with sediment carbon stocks (r = 0.92; p < 0.05) and total seagrass ecosystem carbon stocks (r = 0.92; p < 0.05). Seagrass ecosystems with different community structures showed different carbon storage capacities. Seagrass ecosystems dominated by large-sized species such as E. acoroides showed higher estimated carbon stocks thus suggesting the importance of considering the variability of community structure in managing seagrass ecosystems for carbon sequestration and storage.
海草生态系统被认为是储存碳最有效的沿海生态系统之一。某一生态系统的碳储量估算受物种多样性和生境类型等因素的影响很大。本研究以印度尼西亚卡里蒙查瓦海洋国家公园（Karimunjawa Marine National Park）的六个沿海地点为案例，旨在研究海草生态系统中植物群落结构与碳储量之间的关系。该地区记录了 8 种海草，即 Enhalus acoroides、Thalassia hemprichii、Cymodocea rotundata、Halodule pinifolia、Halophila ovalis、Halophila minor、Syringodium isoetifolium 和 Oceana serrulata。在六个研究地点中，估计最高碳储量为 426.2 兆克碳公顷-1（地点 5；泰拉加，以 E. acoroides 为主）。同时，最低的碳储量估计值为 127.4 Mg C ha-1（地点 4；Koin，以 T. hemprichii 为主）。E. acoroides的密度与海草生物量总碳储量呈正相关（r = 0.97; p <0.01），而其优势度与沉积物碳储量（r = 0.92; p <0.05）和海草生态系统总碳储量（r = 0.92; p <0.05）呈正相关。不同群落结构的海草生态系统表现出不同的碳储存能力。以 E. acoroides 等大型物种为主的海草生态系统估计碳储量较高，这表明在管理海草生态系统以进行碳固存和储存时，考虑群落结构的变化非常重要。
{"title":"Relationship between seagrass community structure and carbon stocks on the coasts of Karimunjawa Marine National Park, Indonesia","authors":"Amelia S.N. Kumala, Devi N. Choesin, Ichsan Suwandhi","doi":"10.1016/j.actao.2024.104030","DOIUrl":"10.1016/j.actao.2024.104030","url":null,"abstract":"<div><div>The seagrass ecosystem is considered one of the most effective coastal ecosystems in storing carbon. Carbon stock estimation for a certain ecosystem is highly affected by factors such as species diversity and habitat type. This study aims to investigate the relationship between plant community structure and carbon stocks in the seagrass ecosystem using a case study of six coastal sites in Karimunjawa Marine National Park, Indonesia. In this region, eight seagrass species were recorded, i.e., <em>Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Halodule pinifolia, Halophila ovalis, Halophila minor, Syringodium isoetifolium,</em> and <em>Oceana serrulata</em>. From the six study sites, the highest estimated carbon stock was 426.2 Mg C ha<sup>−1</sup> (Site 5; Telaga, dominated by <em>E. acoroides</em>). Meanwhile, the lowest estimated carbon stock was 127.4 Mg C ha<sup>−1</sup> (Site 4; Koin, dominated by <em>T. hemprichii</em>)<em>.</em> The density of <em>E. acoroides</em> was positively correlated with the total seagrass biomass carbon stocks (r = 0.97; p < 0.01), while its dominance was positively correlated with sediment carbon stocks (r = 0.92; p < 0.05) and total seagrass ecosystem carbon stocks (r = 0.92; p < 0.05). Seagrass ecosystems with different community structures showed different carbon storage capacities. Seagrass ecosystems dominated by large-sized species such as <em>E. acoroides</em> showed higher estimated carbon stocks thus suggesting the importance of considering the variability of community structure in managing seagrass ecosystems for carbon sequestration and storage.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104030"},"PeriodicalIF":1.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-09-26DOI: 10.1016/j.actao.2024.104033
Daichi Iijima, Takeshi Osawa
Mountain environments change rapidly over short distances along altitudinal gradients, providing an ideal system for exploring the mechanisms that shape biodiversity gradients. Species richness is the most studied diversity metric in mountains, and altitudinal patterns and their shaping mechanisms have been investigated worldwide. Although the altitudinal patterns of species richness in breeding bird assemblages have been extensively studied, less attention has been paid to seasonal changes in patterns between winter and summer. Furthermore, the effects of severe climate in high-elevation areas on seasonal changes in the altitudinal pattern of species richness in insular mountains remain unclear. We investigated changes in the pattern between the breeding and wintering seasons using field and literature surveys in Mount Tsukuba (877 m a.s.l.), central Japan. Temperatures at the middle elevations of the slope are relatively higher than those at the foot of the mountain in winter. The mountain is covered with forests up to its summit. We found that the altitudinal pattern of species richness was the low-plateau during the wintering season. Low-elevation areas were havens for wintering species, whereas high-elevation areas were impoverished in wintering species. Conversely, there was no association between elevation and species richness during the breeding season. Our study suggests that the relaxation of severe climates in high-elevation areas during winter and verdant forests in the highlands during summer are critical mechanisms driving seasonal changes in the altitudinal pattern of species richness. Furthermore, we highlight that comprehensive monitoring, including wintering seasons, is essential for detecting the changes in the diversity patterns of mountain bird assemblages due to the shift in the peak of wintering species richness under ongoing climate change.
{"title":"Seasonal changes in altitudinal patterns of bird species richness in a temperate low-elevation mountain","authors":"Daichi Iijima, Takeshi Osawa","doi":"10.1016/j.actao.2024.104033","DOIUrl":"10.1016/j.actao.2024.104033","url":null,"abstract":"<div><div>Mountain environments change rapidly over short distances along altitudinal gradients, providing an ideal system for exploring the mechanisms that shape biodiversity gradients. Species richness is the most studied diversity metric in mountains, and altitudinal patterns and their shaping mechanisms have been investigated worldwide. Although the altitudinal patterns of species richness in breeding bird assemblages have been extensively studied, less attention has been paid to seasonal changes in patterns between winter and summer. Furthermore, the effects of severe climate in high-elevation areas on seasonal changes in the altitudinal pattern of species richness in insular mountains remain unclear. We investigated changes in the pattern between the breeding and wintering seasons using field and literature surveys in Mount Tsukuba (877 m a.s.l.), central Japan. Temperatures at the middle elevations of the slope are relatively higher than those at the foot of the mountain in winter. The mountain is covered with forests up to its summit. We found that the altitudinal pattern of species richness was the low-plateau during the wintering season. Low-elevation areas were havens for wintering species, whereas high-elevation areas were impoverished in wintering species. Conversely, there was no association between elevation and species richness during the breeding season. Our study suggests that the relaxation of severe climates in high-elevation areas during winter and verdant forests in the highlands during summer are critical mechanisms driving seasonal changes in the altitudinal pattern of species richness. Furthermore, we highlight that comprehensive monitoring, including wintering seasons, is essential for detecting the changes in the diversity patterns of mountain bird assemblages due to the shift in the peak of wintering species richness under ongoing climate change.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104033"},"PeriodicalIF":1.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-09-25DOI: 10.1016/j.actao.2024.104034
E. Elias Johnson , D. Alejandro Espinosa-Lucas , R. Darío Pérez-García , Israel Solano-Zavaleta , J. Jaime Zúñiga-Vega , Gonzalo A. Ramírez-Cruz
Urbanization has forced animals to respond to novel environments. One of the basic questions in urban ecology is if ecological processes that occur in natural conditions also occur in urban environments. In natural ecosystems, key predators can limit prey abundance and have a widespread effect on trophic levels. Here, we examine a predator-prey interaction in Mexico City, an urban ecosystem where prey can be evaluated in the presence or absence of apex predators. Nearly all original ecosystems in Mexico City have been transformed for human purposes. Many of the green spaces in the city contain populations of the Mexican gray squirrel, a species native to this area. These green spaces are also inhabited by different species of raptors, the most frequent being Harris's hawk, Cooper's hawk, and sharp-shinned hawk. Little is known about the interactions between raptors and squirrels, particularly how different environmental factors influence this ecological relationship. We do know, however, that raptors prey on squirrels. We predicted that in parks where raptors were present, there would be fewer squirrels than in parks where there were no raptors. We studied the relationship between raptors and squirrels using occupancy models, which also allowed us to evaluate environmental factors that affect the presence of both squirrels and raptors. We also tested if the presence of raptors influenced the occupancy probability of squirrels, and vice versa. Lastly, we estimated the abundance of squirrels in parks, both where raptors were present and where they were absent. Contrary to our predictions, in our first two sampling periods we found a positive relationship between the presence of raptors and squirrel abundance, but this relationship was absent during our second two survey periods, which was due to a decline in squirrel abundance in parks where raptors were present. These results suggest that predator-prey interactions occur in urban settings much as they do under natural conditions, but that other factors unique to urbanization can also impact the abundance of raptors and squirrels. Our findings also suggest that raptors might be an effective means of controlling squirrel populations under some conditions.
{"title":"Keystone species in an urban environment: Do raptors control the Mexican gray squirrel in Mexico City?","authors":"E. Elias Johnson , D. Alejandro Espinosa-Lucas , R. Darío Pérez-García , Israel Solano-Zavaleta , J. Jaime Zúñiga-Vega , Gonzalo A. Ramírez-Cruz","doi":"10.1016/j.actao.2024.104034","DOIUrl":"10.1016/j.actao.2024.104034","url":null,"abstract":"<div><div>Urbanization has forced animals to respond to novel environments. One of the basic questions in urban ecology is if ecological processes that occur in natural conditions also occur in urban environments. In natural ecosystems, key predators can limit prey abundance and have a widespread effect on trophic levels. Here, we examine a predator-prey interaction in Mexico City, an urban ecosystem where prey can be evaluated in the presence or absence of apex predators. Nearly all original ecosystems in Mexico City have been transformed for human purposes. Many of the green spaces in the city contain populations of the Mexican gray squirrel, a species native to this area. These green spaces are also inhabited by different species of raptors, the most frequent being Harris's hawk, Cooper's hawk, and sharp-shinned hawk. Little is known about the interactions between raptors and squirrels, particularly how different environmental factors influence this ecological relationship. We do know, however, that raptors prey on squirrels. We predicted that in parks where raptors were present, there would be fewer squirrels than in parks where there were no raptors. We studied the relationship between raptors and squirrels using occupancy models, which also allowed us to evaluate environmental factors that affect the presence of both squirrels and raptors. We also tested if the presence of raptors influenced the occupancy probability of squirrels, and vice versa. Lastly, we estimated the abundance of squirrels in parks, both where raptors were present and where they were absent. Contrary to our predictions, in our first two sampling periods we found a positive relationship between the presence of raptors and squirrel abundance, but this relationship was absent during our second two survey periods, which was due to a decline in squirrel abundance in parks where raptors were present. These results suggest that predator-prey interactions occur in urban settings much as they do under natural conditions, but that other factors unique to urbanization can also impact the abundance of raptors and squirrels. Our findings also suggest that raptors might be an effective means of controlling squirrel populations under some conditions.</div></div>","PeriodicalId":55564,"journal":{"name":"Acta Oecologica-International Journal of Ecology","volume":"125 ","pages":"Article 104034"},"PeriodicalIF":1.3,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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