Pub Date : 2024-11-06DOI: 10.1016/j.ecocom.2024.101107
In this paper, we investigate a prey–predator community of fish coexisting in a multi-patches model, where different fishing patches are interconnected through migration terms. Only the predator is caught, while the prey grows logistically on each patch. The main objective of our research is to compare the maximum sustainable yield achieved in two contrasting scenarios: unconnected patches and connected patches with rapid stock movements. We show that the total maximum sustainable yield for the connected patches can be greater than the sum of the maximum sustainable yield on each isolated patch. The analysis of the model allows us to establish the conditions under which one of the two cases is more favorable from the viewpoint of yield. As a result, we provide a complete classification for all possible cases. This valuable information can be used to assist decision-makers in selecting the best management strategy for a particular fishery.
{"title":"Enhancing maximum sustainable yield in a patchy prey–predator environment","authors":"","doi":"10.1016/j.ecocom.2024.101107","DOIUrl":"10.1016/j.ecocom.2024.101107","url":null,"abstract":"<div><div>In this paper, we investigate a prey–predator community of fish coexisting in a multi-patches model, where different fishing patches are interconnected through migration terms. Only the predator is caught, while the prey grows logistically on each patch. The main objective of our research is to compare the maximum sustainable yield achieved in two contrasting scenarios: unconnected patches and connected patches with rapid stock movements. We show that the total maximum sustainable yield for the connected patches can be greater than the sum of the maximum sustainable yield on each isolated patch. The analysis of the model allows us to establish the conditions under which one of the two cases is more favorable from the viewpoint of yield. As a result, we provide a complete classification for all possible cases. This valuable information can be used to assist decision-makers in selecting the best management strategy for a particular fishery.</div></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-30DOI: 10.1016/j.ecocom.2024.101104
Spatial patterns of alternating high and low biomass occur in a wide range of ecosystems. Patterns can improve ecosystem productivity and resilience, but the particular effects of patterning depend on their spatial structure. The spatial structure is conventionally classified as either regular, when the patches of biomass are of similar size and are spaced in similar intervals, or irregular. The formation of regular patterns is driven by scale-dependent feedbacks. Models incorporating those feedbacks generate highly regular patterns, while natural patterns appear less regular. This calls for a more nuanced quantification beyond a binary classification. Here, we propose measuring the degree of regularity by the maximum of a pattern’s spectral density, based on the observation that the density of highly regular patterns consists of a narrow and high peak, while the density of highly irregular patterns consists of a low and wide lobe. We rescale the density to make the measure invariant with respect to the characteristic length-scale of a pattern, facilitating the comparison of patterns observed or modelled under different conditions. We demonstrate our method in a metastudy determining the regularity of natural and model-generated patterns depicted in previous studies. We find that natural patterns have an intermediate degree of regularity, resembling random surfaces generated by stochastic processes. We find that conventional deterministic models do not reproduce the intermediate regularity of natural patterns, as they generate patterns which are much more regular and similar to periodic surfaces. We call for appreciating the stochasticity of natural patterns in systems with scale-dependent feedbacks.
{"title":"A scale-invariant method for quantifying the regularity of environmental spatial patterns","authors":"","doi":"10.1016/j.ecocom.2024.101104","DOIUrl":"10.1016/j.ecocom.2024.101104","url":null,"abstract":"<div><div>Spatial patterns of alternating high and low biomass occur in a wide range of ecosystems. Patterns can improve ecosystem productivity and resilience, but the particular effects of patterning depend on their spatial structure. The spatial structure is conventionally classified as either regular, when the patches of biomass are of similar size and are spaced in similar intervals, or irregular. The formation of regular patterns is driven by scale-dependent feedbacks. Models incorporating those feedbacks generate highly regular patterns, while natural patterns appear less regular. This calls for a more nuanced quantification beyond a binary classification. Here, we propose measuring the degree of regularity by the maximum of a pattern’s spectral density, based on the observation that the density of highly regular patterns consists of a narrow and high peak, while the density of highly irregular patterns consists of a low and wide lobe. We rescale the density to make the measure invariant with respect to the characteristic length-scale of a pattern, facilitating the comparison of patterns observed or modelled under different conditions. We demonstrate our method in a metastudy determining the regularity of natural and model-generated patterns depicted in previous studies. We find that natural patterns have an intermediate degree of regularity, resembling random surfaces generated by stochastic processes. We find that conventional deterministic models do not reproduce the intermediate regularity of natural patterns, as they generate patterns which are much more regular and similar to periodic surfaces. We call for appreciating the stochasticity of natural patterns in systems with scale-dependent feedbacks.</div></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-16DOI: 10.1016/j.ecocom.2024.101105
The honeybee Apis mellifera is an introduced managed pollinator species in many world regions and exhibits a high capacity to compete for resources against native bee species. Despite empirical evidence showing that A. mellifera establishes a great number of interactions within plant-bee interaction networks (i.e., high interactive role), little is known on whether its interactive role changes along elevational gradients. Being motivated by these concerns, here we assessed the species richness of plants, bees, interaction diversity, and the interactive role of A. mellifera within plant-bee interaction networks along an elevation gradient from the coastal dunes (4 m.a.s.l.) of the Gulf of Mexico up to the pine-fir forests (3425 m.a.s.l.) in the extinct volcano Cofre de Perote in Mexico. Moreover, we evaluated the interactive role of A. mellifera’s on the diversity of plant-bee interactions along this elevational gradient. We found a decrease in the richness of plants, bees, interaction diversity as elevation increased, and the interactive role of A. mellifera within the networks also decreased with elevation. Moreover, the interactive role of A. mellifera had no effect on the diversity of plant-bee interactions along the studied elevational gradient. These findings indicate that climatic conditions could be filtering plant and bee species and their interactions, even the interactions of a super generalist species as A. mellifera. In short, our study helps understand the responses of species and their biotic interactions over Neotropical elevational gradients. By examining the pronounced climatic shifts, similar to those induced by climate change, we also highlight the sensitivity of these responses to significant environmental alterations. Our findings underscore the critical importance of understanding ecological dynamics in the face of rapidly changing climates.
蜜蜂（Apis mellifera）是世界上许多地区引进的人工授粉物种，与本地蜜蜂物种竞争资源的能力很强。尽管经验证据表明，蜜蜂在植物-蜜蜂互动网络中建立了大量互动关系（即高互动作用），但人们对蜜蜂的互动作用是否会随着海拔梯度的变化而变化知之甚少。出于这些考虑，我们在此评估了从墨西哥湾沿海沙丘（海拔 4 米）到墨西哥 Cofre de Perote 死火山松杉林（海拔 3425 米）的海拔梯度上植物、蜜蜂的物种丰富度、交互多样性以及 A. mellifera 在植物-蜜蜂交互网络中的交互作用。此外，我们还评估了 A. mellifera 在这一海拔梯度上对植物-蜜蜂相互作用多样性的交互作用。我们发现，随着海拔的升高，植物、蜜蜂和互动多样性的丰富程度有所降低，而 A. mellifera 在网络中的互动作用也随着海拔的升高而降低。此外，在所研究的海拔梯度上，A. mellifera的交互作用对植物-蜜蜂交互作用的多样性没有影响。这些发现表明，气候条件可能会过滤植物和蜜蜂物种及其相互作用，甚至是像A. mellifera这样的超级通才物种的相互作用。简而言之，我们的研究有助于了解物种及其生物相互作用在新热带海拔梯度上的反应。通过研究明显的气候转变（类似于气候变化引起的转变），我们还强调了这些反应对重大环境变化的敏感性。我们的研究结果突出表明，面对快速变化的气候，了解生态动态至关重要。
{"title":"The central importance of the honeybee (Apis mellifera L.) within plant-bee interaction networks decreases along a Neotropical elevational gradient","authors":"","doi":"10.1016/j.ecocom.2024.101105","DOIUrl":"10.1016/j.ecocom.2024.101105","url":null,"abstract":"<div><div>The honeybee <em>Apis mellifera</em> is an introduced managed pollinator species in many world regions and exhibits a high capacity to compete for resources against native bee species. Despite empirical evidence showing that <em>A. mellifera</em> establishes a great number of interactions within plant-bee interaction networks (i.e., high interactive role), little is known on whether its interactive role changes along elevational gradients. Being motivated by these concerns, here we assessed the species richness of plants, bees, interaction diversity, and the interactive role of <em>A. mellifera</em> within plant-bee interaction networks along an elevation gradient from the coastal dunes (4 m.a.s.l.) of the Gulf of Mexico up to the pine-fir forests (3425 m.a.s.l.) in the extinct volcano Cofre de Perote in Mexico. Moreover, we evaluated the interactive role of <em>A. mellifera</em>’s on the diversity of plant-bee interactions along this elevational gradient. We found a decrease in the richness of plants, bees, interaction diversity as elevation increased, and the interactive role of <em>A. mellifera</em> within the networks also decreased with elevation. Moreover, the interactive role of <em>A. mellifera</em> had no effect on the diversity of plant-bee interactions along the studied elevational gradient. These findings indicate that climatic conditions could be filtering plant and bee species and their interactions, even the interactions of a super generalist species as <em>A. mellifera</em>. In short, our study helps understand the responses of species and their biotic interactions over Neotropical elevational gradients. By examining the pronounced climatic shifts, similar to those induced by climate change, we also highlight the sensitivity of these responses to significant environmental alterations. Our findings underscore the critical importance of understanding ecological dynamics in the face of rapidly changing climates.</div></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-16DOI: 10.1016/j.ecocom.2024.101106
Climate change affects Central European forest ecosystems in different ways and, consequently, these changes result in different feedbacks on the provision of forest ecosystem services. Regarding the complexity and the variability in climate-forest interactions outcome, forest decision makers necessitate reliable information about changes in the forest ecosystem services for planning and adaptation purposes. However, forest productivity predictions incorporate multiple levels of uncertainty that have to be regarded to ensure building realistic expectations in forest decision-making. Besides the chosen forest simulation model, uncertainties come from the climate change data represented by a set of representative concentration pathways (RCP), within the underlying ensemble of global circulation and regional climate models (GCM-RCM), and further in the treatment of the CO2-fertilization effect. We considered the mentioned uncertainties in a framework on simulating forest growth and water services for two forest sites, a Sessile oak and a Scots pine stand in Rhineland-Palatine, Germany. The framework revealed a high variability in future forest ecosystem services. Particularly, the variability among the selected GCM-RCM models within the same Representative Concentration Pathway (RCP) was higher than the variability among different RCPs (RCP2.6 and RCP8.5 representing the low and high CO2-emission scenarios, respectively). Sessile oak productivity increased under all scenarios, whereas Scots pine growth declined in the lower end of the RCP8.5 scenario. Water services remained mostly stable at both sites. Moreover, we applied a panel data model to estimate what climate indices caused changes in the forest ecosystem services. We found that Scots pine is more sensitive to a multitude of climate indices, such as temperature changes and Sessile oak showed strong response to the CO2-fertilization. We propose applying this framework to evaluate forest management options under climate change.
{"title":"Assessing the ecological complexity and uncertainty of predicting forest ecosystem services under climate change","authors":"","doi":"10.1016/j.ecocom.2024.101106","DOIUrl":"10.1016/j.ecocom.2024.101106","url":null,"abstract":"<div><div>Climate change affects Central European forest ecosystems in different ways and, consequently, these changes result in different feedbacks on the provision of forest ecosystem services. Regarding the complexity and the variability in climate-forest interactions outcome, forest decision makers necessitate reliable information about changes in the forest ecosystem services for planning and adaptation purposes. However, forest productivity predictions incorporate multiple levels of uncertainty that have to be regarded to ensure building realistic expectations in forest decision-making. Besides the chosen forest simulation model, uncertainties come from the climate change data represented by a set of representative concentration pathways (RCP), within the underlying ensemble of global circulation and regional climate models (GCM-RCM), and further in the treatment of the CO<sub>2</sub>-fertilization effect. We considered the mentioned uncertainties in a framework on simulating forest growth and water services for two forest sites, a Sessile oak and a Scots pine stand in Rhineland-Palatine, Germany. The framework revealed a high variability in future forest ecosystem services. Particularly, the variability among the selected GCM-RCM models within the same Representative Concentration Pathway (RCP) was higher than the variability among different RCPs (RCP2.6 and RCP8.5 representing the low and high CO<sub>2</sub>-emission scenarios, respectively). Sessile oak productivity increased under all scenarios, whereas Scots pine growth declined in the lower end of the RCP8.5 scenario. Water services remained mostly stable at both sites. Moreover, we applied a panel data model to estimate what climate indices caused changes in the forest ecosystem services. We found that Scots pine is more sensitive to a multitude of climate indices, such as temperature changes and Sessile oak showed strong response to the CO<sub>2</sub>-fertilization. We propose applying this framework to evaluate forest management options under climate change.</div></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-16DOI: 10.1016/j.ecocom.2024.101102
Describing mechanisms that ensure stable co-occurrence of sympatric species is fundamental to understanding the complexity of ecological community dynamics. In this study, the Pied flycatcher and the Collared flycatcher were used as model species for the analysis of co-occurrence patterns of closely related hybridising species that inhabit overlapping forest habitats. I hypothesise that spatial niche partitioning between species emerges as a vital adaptive response to interspecific competition and manifests itself in significant shifts in habitat preferences in syntopic areas but not in the allotopic ones. The study leverages a comprehensive dataset that includes species density in 372 randomly selected 1 km² grid cells across the territory of Poland. The analysis of habitat preferences was performed with linear mixed-effect modeling, whereas a contrast analysis was used to investigate changes in habitat preferences resulting from the presence of a competitor. The findings indicate that both species modify their habitat preferences when transitioning between syntopic and allotopic sites. Remarkably, in regions without competitors, such shifts are significantly less pronounced, as demonstrated by the Pied flycatcher that prefers the same habitats both in allopatric regions and allotopic sites. When these results are compared with other studies on closely related hybridising and non-hybridising species, it turns out that what influences the degree and number of niches subjected to competition is the time that passes from species divergence. This study highlights the imperative need to incorporate co-occurrence parameters of closely related species into niche and species distribution models to enhance their ecological realism.
{"title":"Niche divergence mechanisms of closely related hybridising bird species. Modeling approach based on remote sensing data of forest habitats","authors":"","doi":"10.1016/j.ecocom.2024.101102","DOIUrl":"10.1016/j.ecocom.2024.101102","url":null,"abstract":"<div><div>Describing mechanisms that ensure stable co-occurrence of sympatric species is fundamental to understanding the complexity of ecological community dynamics. In this study, the Pied flycatcher and the Collared flycatcher were used as model species for the analysis of co-occurrence patterns of closely related hybridising species that inhabit overlapping forest habitats. I hypothesise that spatial niche partitioning between species emerges as a vital adaptive response to interspecific competition and manifests itself in significant shifts in habitat preferences in syntopic areas but not in the allotopic ones. The study leverages a comprehensive dataset that includes species density in 372 randomly selected 1 km² grid cells across the territory of Poland. The analysis of habitat preferences was performed with linear mixed-effect modeling, whereas a contrast analysis was used to investigate changes in habitat preferences resulting from the presence of a competitor. The findings indicate that both species modify their habitat preferences when transitioning between syntopic and allotopic sites. Remarkably, in regions without competitors, such shifts are significantly less pronounced, as demonstrated by the Pied flycatcher that prefers the same habitats both in allopatric regions and allotopic sites. When these results are compared with other studies on closely related hybridising and non-hybridising species, it turns out that what influences the degree and number of niches subjected to competition is the time that passes from species divergence. This study highlights the imperative need to incorporate co-occurrence parameters of closely related species into niche and species distribution models to enhance their ecological realism.</div></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-16DOI: 10.1016/j.ecocom.2024.101103
Based on the classical idea that no two species can occupy the same niche, ecological communities are frequently assumed to be structured according to the rules of interspecific competition, based on the intuition provided by the Lotka/Volterra competition equations in two dimensions. It has been noted that when three or more species are involved, the usual tacit assumption that all competition is transitive may be violated. Intransitive loops change some of the emergent principles of the competition-based framework of community structure. Since the intransitivity is oscillatory, the convenient stable equilibrium approach to communities is altered and oscillatory behavior of the system needs to be acknowledged. It is likely that real communities, especially if they are relatively large, will contain one or more intransitive structures, along with normal transitivities. Here we examine some theoretical constructs that emanate from the joint consideration of intransitive and transitive structures co-occurring in an ecological community.
{"title":"Transitive and intransitive structures in competition-based ecological communities","authors":"","doi":"10.1016/j.ecocom.2024.101103","DOIUrl":"10.1016/j.ecocom.2024.101103","url":null,"abstract":"<div><div>Based on the classical idea that no two species can occupy the same niche, ecological communities are frequently assumed to be structured according to the rules of interspecific competition, based on the intuition provided by the Lotka/Volterra competition equations in two dimensions. It has been noted that when three or more species are involved, the usual tacit assumption that all competition is transitive may be violated. Intransitive loops change some of the emergent principles of the competition-based framework of community structure. Since the intransitivity is oscillatory, the convenient stable equilibrium approach to communities is altered and oscillatory behavior of the system needs to be acknowledged. It is likely that real communities, especially if they are relatively large, will contain one or more intransitive structures, along with normal transitivities. Here we examine some theoretical constructs that emanate from the joint consideration of intransitive and transitive structures co-occurring in an ecological community.</div></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-10DOI: 10.1016/j.ecocom.2024.101101
Conservation offsets are increasingly used as an instrument for biodiversity conservation on private lands. Since the restoration of degraded land often involves uncertainties and time lags, conservation biologists have recommended that credits in conservation offset schemes be awarded only with the completion of the restoration process (“savings bank”). These arguments, however, ignore that such a scheme design may incur higher economic costs than a design in which credits are already awarded at the initiation of the restoration process (“lending bank”). Here a generic agent-based ecological-economic simulation model is developed to explore the cost-effectiveness of savings and lending banks. The economic model compartment considers spatially heterogeneous and dynamic conservation costs and time preferences in the landowners. The ecological compartment considers uncertainty in the duration and the success of restoration process, and in the metapopulation dynamics of a species described by the rates of local population extinction and the colonisation of empty habitat patches. By this the widely used offset metric of “habitat hectares” is replaced by “metapopulation viability” which is commonly used in conservation biology. It turns out that whether credits should be awarded at the initiation or with completion of restoration depends on the ecological and economic circumstances. Larger colonisation and extinction rates, e.g., tend to favour the awarding of credits with the initiation of habitat restoration.
{"title":"Should the biodiversity bank be a savings bank or a lending bank?","authors":"","doi":"10.1016/j.ecocom.2024.101101","DOIUrl":"10.1016/j.ecocom.2024.101101","url":null,"abstract":"<div><div>Conservation offsets are increasingly used as an instrument for biodiversity conservation on private lands. Since the restoration of degraded land often involves uncertainties and time lags, conservation biologists have recommended that credits in conservation offset schemes be awarded only with the completion of the restoration process (“savings bank”). These arguments, however, ignore that such a scheme design may incur higher economic costs than a design in which credits are already awarded at the initiation of the restoration process (“lending bank”). Here a generic agent-based ecological-economic simulation model is developed to explore the cost-effectiveness of savings and lending banks. The economic model compartment considers spatially heterogeneous and dynamic conservation costs and time preferences in the landowners. The ecological compartment considers uncertainty in the duration and the success of restoration process, and in the metapopulation dynamics of a species described by the rates of local population extinction and the colonisation of empty habitat patches. By this the widely used offset metric of “habitat hectares” is replaced by “metapopulation viability” which is commonly used in conservation biology. It turns out that whether credits should be awarded at the initiation or with completion of restoration depends on the ecological and economic circumstances. Larger colonisation and extinction rates, e.g., tend to favour the awarding of credits with the initiation of habitat restoration.</div></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-08-01DOI: 10.1016/j.ecocom.2024.101093
Numerous studies have demonstrated the significance of climatic and edaphic conditions in regulating the species composition and forest structure. However, there is still a lack of knowledge regarding the ecological processes that are brought about by phenological expression and regeneration. This study postulates that phenology, regeneration, and species dominance are a sequence of intermediary processes through which environmental conditions affect forest structure. In a dry deciduous forest of Similipal Biosphere Reserve (SBR), India, we analysed the relationships between various environmental characteristics, phenological parameters, seedling density, sapling density, and tree density using Structural Equation Modelling (SEM). The study revealed an immediate association between climate and leafing (Path Coefficient: -0.67; T: 9.374; p < 0.01), flowering (Path Coefficient: -0.61; T: 2.981; p < 0.01), and fruiting (Path Coefficient: -0.67; T: 3.51; p < 0.01). The sequential association between seedling and sapling density and forest structure was also significant (p < 0.5). However, these were found to have no direct link with phenology (T < 1; p > 0.05) which has been assumed to be the outcome of anthropogenic activities in the forest having an impact on the system. Comparatively, synchrony of fruit senescence and synchrony of flowering were the principal events that supported regeneration more than others, each accounting for 79 % and 74 % of their data, respectively. On the other hand, the monthly minimum temperature (contributing 97 % of data) was a key contribution to the principal component (PC1) and was primarily responsible for triggering the phenological cycle. Most of the important phenophases were seasonal (Rayleigh's Z varied from 10.93 to 50.01; p < 0.01) except the fruit initiation (Rayleigh's Z = 0.48; p = 0.2). Most of the species (72 % of all species) had regeneration densities that were corresponding to their competitive scores. Similarly, density of adult tree species proportionated with their density in regeneration stage (sapling and seedling), supporting the research hypothesis. However, several deviant species suggested that the system was affected by a wide range of other factors. This is the first study of its kind to evaluate the critical ecological processes together, and recommends further investigation across different woodland ecosystems to deepen understanding of forest functioning.
{"title":"Systematic effects of environmental factors and phenology on forest structure: Tracking the ecological processes","authors":"","doi":"10.1016/j.ecocom.2024.101093","DOIUrl":"10.1016/j.ecocom.2024.101093","url":null,"abstract":"<div><p>Numerous studies have demonstrated the significance of climatic and edaphic conditions in regulating the species composition and forest structure. However, there is still a lack of knowledge regarding the ecological processes that are brought about by phenological expression and regeneration. This study postulates that phenology, regeneration, and species dominance are a sequence of intermediary processes through which environmental conditions affect forest structure. In a dry deciduous forest of Similipal Biosphere Reserve (SBR), India, we analysed the relationships between various environmental characteristics, phenological parameters, seedling density, sapling density, and tree density using Structural Equation Modelling (SEM). The study revealed an immediate association between climate and leafing (Path Coefficient: -0.67; T: 9.374; <em>p</em> < 0.01), flowering (Path Coefficient: -0.61; T: 2.981; <em>p</em> < 0.01), and fruiting (Path Coefficient: -0.67; T: 3.51; <em>p</em> < 0.01). The sequential association between seedling and sapling density and forest structure was also significant (<em>p</em> < 0.5). However, these were found to have no direct link with phenology (<em>T</em> < 1; <em>p</em> > 0.05) which has been assumed to be the outcome of anthropogenic activities in the forest having an impact on the system. Comparatively, synchrony of fruit senescence and synchrony of flowering were the principal events that supported regeneration more than others, each accounting for 79 % and 74 % of their data, respectively. On the other hand, the monthly minimum temperature (contributing 97 % of data) was a key contribution to the principal component (PC1) and was primarily responsible for triggering the phenological cycle. Most of the important phenophases were seasonal (Rayleigh's Z varied from 10.93 to 50.01; <em>p</em> < 0.01) except the fruit initiation (Rayleigh's <em>Z</em> = 0.48; <em>p</em> = 0.2). Most of the species (72 % of all species) had regeneration densities that were corresponding to their competitive scores. Similarly, density of adult tree species proportionated with their density in regeneration stage (sapling and seedling), supporting the research hypothesis. However, several deviant species suggested that the system was affected by a wide range of other factors. This is the first study of its kind to evaluate the critical ecological processes together, and recommends further investigation across different woodland ecosystems to deepen understanding of forest functioning.</p></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-07-11DOI: 10.1016/j.ecocom.2024.101092
Ruijing Yang , Minquan Feng , Zimeng Liu , Xuyan Wang , Zili Qu
The analysis of keystone species based on network structure has increasingly emphasized the significance of quantitative food webs. In this study, Zhangze Lake was chosen as the research subject, and assigned a weighted index to each index by creatively combined isotope techniques with topological important and uniqueness theories, then united centrality theory. Next, various scales of indices were used to examine the importance of each nutrient in the food web, the correlation between the ordering and distribution across indices, and the difference in time. This study revealed that the centrality of phytoplankton was significantly higher in April compared to July. Both of the monthly unique species in this ecosystem were planktivorous feeders, while the keystone species serving as higher consumers were identified to be Exopalaemon modestus. The ranking results of the indices other than the weighted closeness centrality and weighted betweenness centrality showed consistency. Additionally, the distributions of the weighted indices differed significantly from their corresponding unweighted indices, with the weighted centrality indices being more similar to the out-degree ordering and more strongly correlated in April. When only strong interactions between species were considered, there was a negative correlation found between species centrality and uniqueness. Through the quantitative construction of a diet proportion food web model, combined with multiple indices, we have provided a practical solution for holistically and quantitatively identifying key species, thus aiding in the accurate and effective protection of biodiversity.
{"title":"Analysis of keystone species in a quantitative network perspective based on stable isotopes","authors":"Ruijing Yang , Minquan Feng , Zimeng Liu , Xuyan Wang , Zili Qu","doi":"10.1016/j.ecocom.2024.101092","DOIUrl":"https://doi.org/10.1016/j.ecocom.2024.101092","url":null,"abstract":"<div><p>The analysis of keystone species based on network structure has increasingly emphasized the significance of quantitative food webs. In this study, Zhangze Lake was chosen as the research subject, and assigned a weighted index to each index by creatively combined isotope techniques with topological important and uniqueness theories, then united centrality theory. Next, various scales of indices were used to examine the importance of each nutrient in the food web, the correlation between the ordering and distribution across indices, and the difference in time. This study revealed that the centrality of phytoplankton was significantly higher in April compared to July. Both of the monthly unique species in this ecosystem were planktivorous feeders, while the keystone species serving as higher consumers were identified to be <em>Exopalaemon modestus</em>. The ranking results of the indices other than the weighted closeness centrality and weighted betweenness centrality showed consistency. Additionally, the distributions of the weighted indices differed significantly from their corresponding unweighted indices, with the weighted centrality indices being more similar to the out-degree ordering and more strongly correlated in April. When only strong interactions between species were considered, there was a negative correlation found between species centrality and uniqueness. Through the quantitative construction of a diet proportion food web model, combined with multiple indices, we have provided a practical solution for holistically and quantitatively identifying key species, thus aiding in the accurate and effective protection of biodiversity.</p></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141593168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-07-10DOI: 10.1016/j.ecocom.2024.101091
Yijun Ren , Ying Gong , Yue Yu , Xinghao Chen , Langqin Yu , Lei Zhao
Exploring how food webs are assembled from basic modules is charming and crucial for understanding how communities are self-organized. As one of the basic modules, intraguild predation (IGP) consists of a prey being consumed by both an intermediate and a top predator, with the former also being consumed by the latter (thus encompassing both predation and competition). This interaction has been shown to govern food web stability, and therefore underpin the organization of network structures. While some studies have been made in understanding the factors and mechanisms behind the prevalence of IGP modules in food webs, the specific role of food web topological structures in relation to these modules remains largely unexplored and is not well understood. Here, 103 food webs were analyzed, and we found that the number of modules in each food web was largely determined by taxon richness and connectance. After controlling richness and connectance, the specific scale-free pattern and core-periphery structure of empirical food webs explains the higher prevalence of IGP modules in empirical food webs better than by chance. Lastly, the loss of taxa which supported large number of IGP modules would lead to serious damage to food web robustness, indicating the keystone role of these taxa in maintaining food web structure and stability. Our results provide new insight into the assembly of empirical food webs from the perspective of IGP modules.
{"title":"Topological traits are associated with the prevalence of IGP modules in empirical food webs","authors":"Yijun Ren , Ying Gong , Yue Yu , Xinghao Chen , Langqin Yu , Lei Zhao","doi":"10.1016/j.ecocom.2024.101091","DOIUrl":"https://doi.org/10.1016/j.ecocom.2024.101091","url":null,"abstract":"<div><p>Exploring how food webs are assembled from basic modules is charming and crucial for understanding how communities are self-organized. As one of the basic modules, intraguild predation (IGP) consists of a prey being consumed by both an intermediate and a top predator, with the former also being consumed by the latter (thus encompassing both predation and competition). This interaction has been shown to govern food web stability, and therefore underpin the organization of network structures. While some studies have been made in understanding the factors and mechanisms behind the prevalence of IGP modules in food webs, the specific role of food web topological structures in relation to these modules remains largely unexplored and is not well understood. Here, 103 food webs were analyzed, and we found that the number of modules in each food web was largely determined by taxon richness and connectance. After controlling richness and connectance, the specific scale-free pattern and core-periphery structure of empirical food webs explains the higher prevalence of IGP modules in empirical food webs better than by chance. Lastly, the loss of taxa which supported large number of IGP modules would lead to serious damage to food web robustness, indicating the keystone role of these taxa in maintaining food web structure and stability. Our results provide new insight into the assembly of empirical food webs from the perspective of IGP modules.</p></div>","PeriodicalId":50559,"journal":{"name":"Ecological Complexity","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141593169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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