Pub Date : 2024-09-10DOI: 10.1101/2024.09.08.611896
Thibaud Decaens, George G Brown, Erin K Cameron, Csaba Csuzdi, Nico Eisenhauer, Sylvain Gerard, Arnaud Goulpeau, Mickael Hedde, Samuel James, Emmanuel Lapied, Marie-Eugenie Maggia, Daniel F Marchan, Jerome Mathieu, Helen RP Phillips, Eric Marcon
Estimating the overall number of species for a given taxon is a central issue in ecology and conservation biology. It should be particularly topical in the case of soil organisms, which represent the majority of known species, but it still suffers from a considerable taxonomic knowledge deficit. We propose here an estimation of the global number of earthworm species based on the Joppa approach, which models taxonomic effort over time in order to estimate the total number of known and, as yet, unknown species in a given taxa. We also conducted regional assessments of species numbers, which allowed us to refine global estimates by providing an accurate overview of the taxonomic deficit in different latitudinal locations on the planet. Our results allow us to propose a conservative estimation of global diversity of the order of 30,000 species. This means that the 5,679 species and subspecies already described represent at best around 20% of the global number of earthworm species. Considering the current rate of new species description, we calculate that it would take at least 120 years to describe all the species existing on Earth. We discuss the strategies that could be developed to reduce the magnitude of this taxonomic deficit.
{"title":"A can of worms: estimating the global number of earthworm species","authors":"Thibaud Decaens, George G Brown, Erin K Cameron, Csaba Csuzdi, Nico Eisenhauer, Sylvain Gerard, Arnaud Goulpeau, Mickael Hedde, Samuel James, Emmanuel Lapied, Marie-Eugenie Maggia, Daniel F Marchan, Jerome Mathieu, Helen RP Phillips, Eric Marcon","doi":"10.1101/2024.09.08.611896","DOIUrl":"https://doi.org/10.1101/2024.09.08.611896","url":null,"abstract":"Estimating the overall number of species for a given taxon is a central issue in ecology and conservation biology. It should be particularly topical in the case of soil organisms, which represent the majority of known species, but it still suffers from a considerable taxonomic knowledge deficit. We propose here an estimation of the global number of earthworm species based on the Joppa approach, which models taxonomic effort over time in order to estimate the total number of known and, as yet, unknown species in a given taxa. We also conducted regional assessments of species numbers, which allowed us to refine global estimates by providing an accurate overview of the taxonomic deficit in different latitudinal locations on the planet. Our results allow us to propose a conservative estimation of global diversity of the order of 30,000 species. This means that the 5,679 species and subspecies already described represent at best around 20% of the global number of earthworm species. Considering the current rate of new species description, we calculate that it would take at least 120 years to describe all the species existing on Earth. We discuss the strategies that could be developed to reduce the magnitude of this taxonomic deficit.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1101/2024.09.06.611601
Luuk Croijmans, Daan Mertens, Dirk F. van Apeldoorn, Yufei Jia, Nelson Rios Hernandez, Erik H. Poelman
Industrialized agriculture needs sustainable alternatives to pesticides to avoid negative impacts on the environment and human health. Crop diversification is known to decrease pest pressure in agricultural crops. Up till now, effects of insect herbivores on crop yield are often assumed equal among cropping systems. Here, we show that cropping system alters the effect that herbivores have on cabbage crop yield, where more herbivores do not necessarily lead to reduced yields. Our most diverse cropping system had simultaneously the highest number of herbivores and highest crop yield. Conversely, in a cultivar mixture we observed negative impacts of herbivores on yield. Our study shows that, in addition to the time of arrival and type of herbivore, cropping system should be considered when assessing how insect herbivores affect crop yield. We emphasize how our perception of herbivorous insects as pests is flawed and limits conservation efforts and sustainable farming practices.
{"title":"Herbivore prevalence poorly predicts yield in diverse cropping systems","authors":"Luuk Croijmans, Daan Mertens, Dirk F. van Apeldoorn, Yufei Jia, Nelson Rios Hernandez, Erik H. Poelman","doi":"10.1101/2024.09.06.611601","DOIUrl":"https://doi.org/10.1101/2024.09.06.611601","url":null,"abstract":"Industrialized agriculture needs sustainable alternatives to pesticides to avoid negative impacts on the environment and human health. Crop diversification is known to decrease pest pressure in agricultural crops. Up till now, effects of insect herbivores on crop yield are often assumed equal among cropping systems. Here, we show that cropping system alters the effect that herbivores have on cabbage crop yield, where more herbivores do not necessarily lead to reduced yields. Our most diverse cropping system had simultaneously the highest number of herbivores and highest crop yield. Conversely, in a cultivar mixture we observed negative impacts of herbivores on yield. Our study shows that, in addition to the time of arrival and type of herbivore, cropping system should be considered when assessing how insect herbivores affect crop yield. We emphasize how our perception of herbivorous insects as pests is flawed and limits conservation efforts and sustainable farming practices.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1101/2024.09.06.611626
Thi Minh Thao Le, Sten Madec, Erida Gjini
How does coexistence of multiple species or pathogen strains arise in a system? What do coexistence patterns in time and space reveal about the epidemiology, ecology and evolution of such systems? Species abundance patterns often defy fully mechanistic explanations, especially when compositional variation and relative taxa abundances differ across settings. To link such variation to deterministic biological processes in a cause-and-effect fashion requires modeling frameworks that are general in spirit, simple enough to understand and implement, and easily-applicable to multi-site data and their environmental gradients. Here, we propose a method to study variation in serotype frequencies of Streptococcus pneumoniae bacteria across different geographic endemic settings. We use the framework of replicator dynamics, derived for a multi-strain SIS model with co-colonization, to extract from 5 countries data fundamental parameters of inter-strain interactions, based on pairwise invasion fitnesses and their context-dependence. We integrate serotype frequency distributions and serotype identities (SAD + identities) collected from cross-sectional epidemiological surveys in Denmark, Nepal, Iran, Brazil and Mozambique. The snapshot observations are modelled under the same nested framework, by which we present a rationale for mechanistically linking and fitting multi-strain distributions across sites. Besides yielding an effective numerical estimation for more than 70% of the 92 x 92 (αij) in the pneumococcus serotype interaction matrix, this study offers a new proof-of-concept in the inference of random multi-species interactions. We show that in pneumococcus the vast majority of standardized interaction coefficients in co-colonization are concentrated near zero, with a few serotype pairs displaying extreme deviations from the mean. This statistical pattern confirms that the co-colonization coefficients in pneumococcus display a random probability distribution governed by a limited set of parameters, which are slightly modulated in each epidemiological context to shape coexistence. We also discuss key assumptions that must be carefully balanced in the estimation procedure. Our study paves the way for a deeper qualitative and quantitative understanding of the high-dimensional interaction landscape in multi-strain co-colonization systems.
{"title":"Nested inference of pairwise interactions from strain frequency data across settings and context-dependent mutual invasibilities","authors":"Thi Minh Thao Le, Sten Madec, Erida Gjini","doi":"10.1101/2024.09.06.611626","DOIUrl":"https://doi.org/10.1101/2024.09.06.611626","url":null,"abstract":"How does coexistence of multiple species or pathogen strains arise in a system? What do coexistence patterns in time and space reveal about the epidemiology, ecology and evolution of such systems? Species abundance patterns often defy fully mechanistic explanations, especially when compositional variation and relative taxa abundances differ across settings. To link such variation to deterministic biological processes in a cause-and-effect fashion requires modeling frameworks that are general in spirit, simple enough to understand and implement, and easily-applicable to multi-site data and their environmental gradients. Here, we propose a method to study variation in serotype frequencies of Streptococcus pneumoniae bacteria across different geographic endemic settings. We use the framework of replicator dynamics, derived for a multi-strain SIS model with co-colonization, to extract from 5 countries data fundamental parameters of inter-strain interactions, based on pairwise invasion fitnesses and their context-dependence. We integrate serotype frequency distributions and serotype identities (SAD + identities) collected from cross-sectional epidemiological surveys in Denmark, Nepal, Iran, Brazil and Mozambique. The snapshot observations are modelled under the same nested framework, by which we present a rationale for mechanistically linking and fitting multi-strain distributions across sites. Besides yielding an effective numerical estimation for more than 70% of the 92 x 92 (α<sub>ij</sub>) in the pneumococcus serotype interaction matrix, this study offers a new proof-of-concept in the inference of random multi-species interactions. We show that in pneumococcus the vast majority of standardized interaction coefficients in co-colonization are concentrated near zero, with a few serotype pairs displaying extreme deviations from the mean. This statistical pattern confirms that the co-colonization coefficients in pneumococcus display a random probability distribution governed by a limited set of parameters, which are slightly modulated in each epidemiological context to shape coexistence. We also discuss key assumptions that must be carefully balanced in the estimation procedure. Our study paves the way for a deeper qualitative and quantitative understanding of the high-dimensional interaction landscape in multi-strain co-colonization systems.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1101/2024.09.06.611638
Ang Hu, Yifan Cui, Sarah Bercovici, Andrew Tanentzap, Jay Lennon, Xiaopei Lin, Yuanhe Yang, Yongqin Liu, Helena Osterholz, Hailiang Dong, Yahai Lu, Nianzhi Jiao, Jianjun Wang
How dissolved organic matter (DOM) responds to climate warming is critical for understanding its effectiveness as a natural climate solution. Here, we use a highly resolved dataset of 821 DOM samples covering the surface waters to the deep Atlantic, Southern, and Pacific oceans to examine molecular-level responses to warming water temperatures, i.e. their thermal responses. In general, the strength and diversity of thermal responses among individual molecules both decline towards the deep waters, but they show decreasing and increasing trends with more recalcitrant molecules in concentration, respectively. Their contrasting trends concur with the more important role of photochemical processes in explaining the diversity of thermal responses than the strength. By projecting global ocean thermal responses from 1950-2020, we predict increases in the diversity are unexpectedly largest at deeper depths (> 1,000 m). Such increases could elevate recalcitrant deep-ocean carbon sink by approximately 10 Tg C yr-1 which accounts for > 5% of the carbon flux survived to the deep ocean. Our findings highlight the importance of photochemical legacies in driving DOM thermal responses and further help predict the future oceanic carbon sink under global change.
溶解有机物（DOM）如何应对气候变暖对于了解其作为自然气候解决方案的有效性至关重要。在这里，我们使用了一个由 821 个溶解有机物样本组成的高分辨率数据集，涵盖了从表层水到大西洋、南大洋和太平洋深海的水域，以研究分子层面对水温变暖的反应，即热反应。一般来说，单个分子的热反应强度和多样性在向深海移动时都会下降，但随着分子浓度的增加，它们分别呈现出下降和上升的趋势。它们的对比趋势表明，光化学过程在解释热反应多样性方面的作用比热反应强度更为重要。通过预测 1950-2020 年的全球海洋热响应，我们预测在更深的海域（1000 米），热响应多样性的增加会出乎意料地最大。这种增加可能会使深海碳汇增加约10 Tg C/yr-1，占深海存活碳通量的5%。我们的发现强调了光化学遗留物在驱动 DOM 热反应中的重要性，并进一步帮助预测全球变化下的未来海洋碳汇。
{"title":"Photochemical processes drive thermal responses of dissolved organic matter in the dark ocean","authors":"Ang Hu, Yifan Cui, Sarah Bercovici, Andrew Tanentzap, Jay Lennon, Xiaopei Lin, Yuanhe Yang, Yongqin Liu, Helena Osterholz, Hailiang Dong, Yahai Lu, Nianzhi Jiao, Jianjun Wang","doi":"10.1101/2024.09.06.611638","DOIUrl":"https://doi.org/10.1101/2024.09.06.611638","url":null,"abstract":"How dissolved organic matter (DOM) responds to climate warming is critical for understanding its effectiveness as a natural climate solution. Here, we use a highly resolved dataset of 821 DOM samples covering the surface waters to the deep Atlantic, Southern, and Pacific oceans to examine molecular-level responses to warming water temperatures, i.e. their thermal responses. In general, the strength and diversity of thermal responses among individual molecules both decline towards the deep waters, but they show decreasing and increasing trends with more recalcitrant molecules in concentration, respectively. Their contrasting trends concur with the more important role of photochemical processes in explaining the diversity of thermal responses than the strength. By projecting global ocean thermal responses from 1950-2020, we predict increases in the diversity are unexpectedly largest at deeper depths (> 1,000 m). Such increases could elevate recalcitrant deep-ocean carbon sink by approximately 10 Tg C yr-1 which accounts for > 5% of the carbon flux survived to the deep ocean. Our findings highlight the importance of photochemical legacies in driving DOM thermal responses and further help predict the future oceanic carbon sink under global change.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1101/2024.09.05.611377
Rory S Lennox, Angus R McIntosh, Hao Ran Lai, Daniel B Stouffer, Nixie C Boddy, Christian Zammit, Jonathan D Tonkin
In rivers, we are seeing a shift away from natural flow regimes towards larger and more frequent extreme drought and flood events. However, it is unclear how increasing intensity and frequency of extreme flow disturbances will play out alongside existing biotic pressures, such as biological invasions, to impact aquatic biodiversity. In New Zealand, vulnerable native non-diadromous galaxiid fishes face pressure from introduced trout through interspecific competition and predation, which may influence the recovery of native galaxiids after flood disturbances. Here, we employed a capture-mark-recapture study across 12 sites, along a gradient of disturbance following a major flood event, to examine the impact of extreme flooding on the population structure of non-diadromous galaxiids (Galaxias vulgaris and G. paucispondylus), and the effect of trout presence on individual galaxiid growth rates recovering from this event. We found a lower abundance of all non-diadromous galaxiid size classes under higher flood magnitudes, but smaller size classes (i.e., young-of-year and 1-2 year cohorts) were more impacted. Furthermore, the presence of trout, whether at low or high abundances, reduced the individual growth of native non-diadromous galaxiids, despite interspecific effects being a weaker regulator of individual growth compared to conspecific effects. Moreover, trout effects on galaxiids varied by both galaxiid size and density, such that growth of smaller individual galaxiids in low densities were most affected by the presence of trout regardless of trout density. In summary, our results demonstrate that non-diadromous galaxiid population dynamics in future are likely to be affected by flood disturbance regimes and introduced trout presence, the outcome of which involves a complex balance between reduced population persistence and increased individual resistance of larger individuals. Conservation efforts that focus on maintaining strategically placed trout-free source populations of adult galaxiids could therefore be an important tool to enable native dispersal into trout-affected habitat and maintain population resilience in the face of increasingly larger and more frequent extreme events, given that recruitment of non-diadromous galaxiids is higher in the absence of trout.
{"title":"Introduced trout hinder the recovery of native fish following an extreme flood disturbance","authors":"Rory S Lennox, Angus R McIntosh, Hao Ran Lai, Daniel B Stouffer, Nixie C Boddy, Christian Zammit, Jonathan D Tonkin","doi":"10.1101/2024.09.05.611377","DOIUrl":"https://doi.org/10.1101/2024.09.05.611377","url":null,"abstract":"In rivers, we are seeing a shift away from natural flow regimes towards larger and more frequent extreme drought and flood events. However, it is unclear how increasing intensity and frequency of extreme flow disturbances will play out alongside existing biotic pressures, such as biological invasions, to impact aquatic biodiversity. In New Zealand, vulnerable native non-diadromous galaxiid fishes face pressure from introduced trout through interspecific competition and predation, which may influence the recovery of native galaxiids after flood disturbances. Here, we employed a capture-mark-recapture study across 12 sites, along a gradient of disturbance following a major flood event, to examine the impact of extreme flooding on the population structure of non-diadromous galaxiids (Galaxias vulgaris and G. paucispondylus), and the effect of trout presence on individual galaxiid growth rates recovering from this event. We found a lower abundance of all non-diadromous galaxiid size classes under higher flood magnitudes, but smaller size classes (i.e., young-of-year and 1-2 year cohorts) were more impacted. Furthermore, the presence of trout, whether at low or high abundances, reduced the individual growth of native non-diadromous galaxiids, despite interspecific effects being a weaker regulator of individual growth compared to conspecific effects. Moreover, trout effects on galaxiids varied by both galaxiid size and density, such that growth of smaller individual galaxiids in low densities were most affected by the presence of trout regardless of trout density. In summary, our results demonstrate that non-diadromous galaxiid population dynamics in future are likely to be affected by flood disturbance regimes and introduced trout presence, the outcome of which involves a complex balance between reduced population persistence and increased individual resistance of larger individuals. Conservation efforts that focus on maintaining strategically placed trout-free source populations of adult galaxiids could therefore be an important tool to enable native dispersal into trout-affected habitat and maintain population resilience in the face of increasingly larger and more frequent extreme events, given that recruitment of non-diadromous galaxiids is higher in the absence of trout.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1101/2024.06.13.598783
Claus Rueffler, Laurent Lehmann
Many seabirds congregate in large colonies for breeding, a time when they are central place foragers. An influential idea in seabird ecology posits that competition during breeding results in an area of reduced prey availability around colonies, a phenomenon known as Ashmole's halo, and that this limits colony size. This idea has gained empirical support, including the finding that species coexisting within a colony might be able to do so by foraging on a single prey species but at different distances. Here, we provide a comprehensive mathematical model for central place foragers exploiting a single prey in a two-dimensional environment, where the prey distribution is the result of intrinsic birth and death, movement in space and mortality due to foraging birds (we also consider a variant tailored toward colonial social insects). Bird predation at different distances occurs according to an ideal free foraging distribution that maximizes prey delivery under flight and search costs. We fully characterize the birds' ideal free distribution and the prey distribution it generates. Our results show that prey depletion halos around breeding colonies are a robust phenomenon and that the birds' ideal free distribution is sensitive to prey movement. Furthermore, coexistence of several seabird species on a single prey easily emerges through behavioral niche partitioning whenever trait differences between species entail trade-offs between efficiently exploiting a scarce prey close to the colony and a more abundant prey far away. Such behavioral-based coexistence-inducing mechanism should generalize to other habitat and diet choice scenarios.
{"title":"Central place foragers, prey depletion halos, and how behavioral niche partitioning promotes consumer coexistence","authors":"Claus Rueffler, Laurent Lehmann","doi":"10.1101/2024.06.13.598783","DOIUrl":"https://doi.org/10.1101/2024.06.13.598783","url":null,"abstract":"Many seabirds congregate in large colonies for breeding, a time when they are central place foragers. An influential idea in seabird ecology posits that competition during breeding results in an area of reduced prey availability around colonies, a phenomenon known as Ashmole's halo, and that this limits colony size. This idea has gained empirical support, including the finding that species coexisting within a colony might be able to do so by foraging on a single prey species but at different distances. Here, we provide a comprehensive mathematical model for central place foragers exploiting a single prey in a two-dimensional environment, where the prey distribution is the result of intrinsic birth and death, movement in space and mortality due to foraging birds (we also consider a variant tailored toward colonial social insects). Bird predation at different distances occurs according to an ideal free foraging distribution that maximizes prey delivery under flight and search costs. We fully characterize the birds' ideal free distribution and the prey distribution it generates. Our results show that prey depletion halos around breeding colonies are a robust phenomenon and that the birds' ideal free distribution is sensitive to prey movement. Furthermore, coexistence of several seabird species on a single prey easily emerges through behavioral niche partitioning whenever trait differences between species entail trade-offs between efficiently exploiting a scarce prey close to the colony and a more abundant prey far away. Such behavioral-based coexistence-inducing mechanism should generalize to other habitat and diet choice scenarios.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-08DOI: 10.1101/2024.09.07.611535
Benjamin Rutschmann, Patrick Laurenz Kohl, Ingolf Steffan-Dewenter
Investigating the life history of social insect colonies and the demography of their populations are important for their conservation, but data collection is challenging. There is a growing interest in understanding the population status of wild-living honeybee colonies across Europe, for which it is critical to collect data on survival and natality rates. Although survival rates can be investigated through regular inspections of wild nests, the accurate quantification of natality rates (i.e., the number of swarms produced per colony per year) remains a significant challenge. Using digital weight scales, we remotely monitored the natural swarming behavior of ten unmanaged Apis mellifera carnica colonies housed in static-volume hives (45L) in a forest region of southern Germany. During the 2019 season, between mid-May and late June, we recorded 17 swarming events, averaging 1.7 swarms per colony. Our observations offer a reference point for the timing, frequency, and size of honeybee swarms that helps us understand the natural reproductive patterns of wild-living honeybees in a temperate forest environment.
{"title":"Swarming rate and timing of unmanaged honeybee colonies (Apis mellifera carnica) in a forest environment","authors":"Benjamin Rutschmann, Patrick Laurenz Kohl, Ingolf Steffan-Dewenter","doi":"10.1101/2024.09.07.611535","DOIUrl":"https://doi.org/10.1101/2024.09.07.611535","url":null,"abstract":"Investigating the life history of social insect colonies and the demography of their populations are important for their conservation, but data collection is challenging. There is a growing interest in understanding the population status of wild-living honeybee colonies across Europe, for which it is critical to collect data on survival and natality rates. Although survival rates can be investigated through regular inspections of wild nests, the accurate quantification of natality rates (i.e., the number of swarms produced per colony per year) remains a significant challenge. Using digital weight scales, we remotely monitored the natural swarming behavior of ten unmanaged <em>Apis mellifera carnica</em> colonies housed in static-volume hives (45L) in a forest region of southern Germany. During the 2019 season, between mid-May and late June, we recorded 17 swarming events, averaging 1.7 swarms per colony. Our observations offer a reference point for the timing, frequency, and size of honeybee swarms that helps us understand the natural reproductive patterns of wild-living honeybees in a temperate forest environment.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-08DOI: 10.1101/2024.09.04.611199
Moritz Mercker, Verena Peschko, Kai Borkenhagen, Nele Markones, Henriette Schwemmer, Volker Dierschke, Stefan Garthe
A differentiated understanding of how regional human activities affect the spatial distribution and numbers of animals within specific areas of interest is of great ecological importance. Estimating these effects from empirical data is challenging however, because human activities can affect animals in qualitatively different ways and on different spatial and temporal scales. In addition, spatio-temporal animal abundance is frequently influenced by factors intrinsic and extrinsic to the area of interest, potentially confounding impact studies, e.g., based on trends. In this study, we synergistically combined regression and mechanistic modelling to separate these different influences. We first used partial differential equations to simulate various potential animal redistribution patterns affected by regional human activities. We then selected appropriate patterns as predictors in regression-based species distribution models, together with additional anthropogenic and natural covariates. The simultaneous consideration of large-scale (number-conserving) animal reorganisation, their regional loss or gain, and the influence of additional environmental covariates eventually allowed the generation of qualitative and quantitative estimates and predictions of human-induced changes. We exemplarily applied our approach to investigate the current and future impact of increasing offshore wind farm (OWF) implementation in the German North Sea on common murres (Uria aalge) during autumn. OWFs constructed up to 2019 reduced common murre numbers in German waters by 18.3%. If the planned OWF priority and reservation areas outlined in the German Marine Spatial Plan are implemented, the predicted loss would increase to 77.7%. Notably, these predictions did not include additional anthropogenic activities or further plans for OWF installation, which could together lead to the almost complete disappearance of common murres from the German North Sea. By directly comparing predicted animal numbers and distributions in hypothetical scenarios with and without human pressures, the presented method allows us to measure and predict the effects of human activities on regional trends and large-scale reorganisation. This in turn helps us to quantify and predict the impact of planned human activities on wildlife, including in the context of the current rapid expansion of alternative energies.
{"title":"Loss or redistribution? A better way of estimating regional changes in animal distribution and numbers caused by increased human activities","authors":"Moritz Mercker, Verena Peschko, Kai Borkenhagen, Nele Markones, Henriette Schwemmer, Volker Dierschke, Stefan Garthe","doi":"10.1101/2024.09.04.611199","DOIUrl":"https://doi.org/10.1101/2024.09.04.611199","url":null,"abstract":"A differentiated understanding of how regional human activities affect the spatial distribution and numbers of animals within specific areas of interest is of great ecological importance. Estimating these effects from empirical data is challenging however, because human activities can affect animals in qualitatively different ways and on different spatial and temporal scales. In addition, spatio-temporal animal abundance is frequently influenced by factors intrinsic and extrinsic to the area of interest, potentially confounding impact studies, e.g., based on trends. In this study, we synergistically combined regression and mechanistic modelling to separate these different influences. We first used partial differential equations to simulate various potential animal redistribution patterns affected by regional human activities. We then selected appropriate patterns as predictors in regression-based species distribution models, together with additional anthropogenic and natural covariates. The simultaneous consideration of large-scale (number-conserving) animal reorganisation, their regional loss or gain, and the influence of additional environmental covariates eventually allowed the generation of qualitative and quantitative estimates and predictions of human-induced changes. We exemplarily applied our approach to investigate the current and future impact of increasing offshore wind farm (OWF) implementation in the German North Sea on common murres (Uria aalge) during autumn. OWFs constructed up to 2019 reduced common murre numbers in German waters by 18.3%. If the planned OWF priority and reservation areas outlined in the German Marine Spatial Plan are implemented, the predicted loss would increase to 77.7%. Notably, these predictions did not include additional anthropogenic activities or further plans for OWF installation, which could together lead to the almost complete disappearance of common murres from the German North Sea. By directly comparing predicted animal numbers and distributions in hypothetical scenarios with and without human pressures, the presented method allows us to measure and predict the effects of human activities on regional trends and large-scale reorganisation. This in turn helps us to quantify and predict the impact of planned human activities on wildlife, including in the context of the current rapid expansion of alternative energies.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-08DOI: 10.1101/2024.09.05.611527
Jason Cosens Walsman, Arietta E Fleming-Davies, Richard Hall, Dana Hawley
Anthropogenic food provisioning provides massive inputs of food to wildlife, with profound ecological and evolutionary consequences. By altering wildlife condition, density, and behavior, provisioning can influence transmission of infectious diseases and thus may impose strong selection pressure on wildlife pathogens. But surprisingly, we lack theory on the eco-evolutionary consequences of provisioning for host-pathogen dynamics. Here we develop a mathematical model of the eco-evolutionary dynamics of a wildlife pathogen under provisioning, motivated by Mycoplasma gallisepticum, a bacterial pathogen that emerged, spread, and changed its virulence in provisioned house finches. We model how provisioning influences the evolution of pathogen virulence, defined here as mortality associated with infection. Consistent with past empirical work, house finches recover from infection and acquire incomplete immunity; this incomplete immunity is stronger if their initial infection was with a more virulent pathogen strain. We find that, even though provisioning improves body condition, it should still select for higher virulence, and thus may actually lead to declines in host populations. These negative effects arise because provisioning magnifies the impact of incomplete immunity, selecting for higher virulence and driving host populations down. Our results highlight that food provisioning can select for more virulent pathogens, with potentially far-reaching implications for conservation.
{"title":"Wildlife provisioning selects for higher pathogen virulence in hosts with incomplete immunity","authors":"Jason Cosens Walsman, Arietta E Fleming-Davies, Richard Hall, Dana Hawley","doi":"10.1101/2024.09.05.611527","DOIUrl":"https://doi.org/10.1101/2024.09.05.611527","url":null,"abstract":"Anthropogenic food provisioning provides massive inputs of food to wildlife, with profound ecological and evolutionary consequences. By altering wildlife condition, density, and behavior, provisioning can influence transmission of infectious diseases and thus may impose strong selection pressure on wildlife pathogens. But surprisingly, we lack theory on the eco-evolutionary consequences of provisioning for host-pathogen dynamics. Here we develop a mathematical model of the eco-evolutionary dynamics of a wildlife pathogen under provisioning, motivated by Mycoplasma gallisepticum, a bacterial pathogen that emerged, spread, and changed its virulence in provisioned house finches. We model how provisioning influences the evolution of pathogen virulence, defined here as mortality associated with infection. Consistent with past empirical work, house finches recover from infection and acquire incomplete immunity; this incomplete immunity is stronger if their initial infection was with a more virulent pathogen strain. We find that, even though provisioning improves body condition, it should still select for higher virulence, and thus may actually lead to declines in host populations. These negative effects arise because provisioning magnifies the impact of incomplete immunity, selecting for higher virulence and driving host populations down. Our results highlight that food provisioning can select for more virulent pathogens, with potentially far-reaching implications for conservation.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-08DOI: 10.1101/2024.09.04.611292
Miguel Lurgi, Alberto Pascual-García
Understanding the factors that influence the persistence and stability of complex ecological networks is a central focus of ecological research. Recent research into these factors has predominantly attempted to unveil the ecological processes and structural constraints that influence network stability. Comparatively little attention has been given to the consequences of evolutionary events, despite the fact that the interplay between ecology and evolution has been recognised as fundamental to understand the formation of ecological communities and predict their reaction to change. In light of current environmental challenges, there is a compelling need for a quantitative framework to predict biodiversity loss under environmental perturbations while accounting for evolutionary processes. We extend existing mutualistic population dynamical models by incorporating evolutionary adaptation events to address this critical gap. We relate ecological aspects of mutualistic community stability to the stability of persistent evolutionary pathways. Our findings highlight the significance of the structural stability of ecological systems in predicting biodiversity loss under both evolutionary and environmental changes, particularly in relation to species-level selection. Notably, our simulations reveal that the evolution of mutualistic networks tends to increase a network-dependent parameter termed critical competition, which places systems in a regime in which mutualistic interactions enhance structural stability and, consequently, biodiversity. This research emphasizes the pivotal role of natural selection in shaping ecological networks, steering them towards reduced effective competition below a critical threshold where mutualistic interactions foster stability. The outcomes of our study contribute to the development of a predictive framework for eco-evolutionary dynamics, offering insights into the interplay between ecological and evolutionary processes in the face of environmental change.
{"title":"Structural stability determines evolutionary stability in mutualistic model ecosystems","authors":"Miguel Lurgi, Alberto Pascual-García","doi":"10.1101/2024.09.04.611292","DOIUrl":"https://doi.org/10.1101/2024.09.04.611292","url":null,"abstract":"Understanding the factors that influence the persistence and stability of complex ecological networks is a central focus of ecological research. Recent research into these factors has predominantly attempted to unveil the ecological processes and structural constraints that influence network stability. Comparatively little attention has been given to the consequences of evolutionary events, despite the fact that the interplay between ecology and evolution has been recognised as fundamental to understand the formation of ecological communities and predict their reaction to change. In light of current environmental challenges, there is a compelling need for a quantitative framework to predict biodiversity loss under environmental perturbations while accounting for evolutionary processes.\u0000We extend existing mutualistic population dynamical models by incorporating evolutionary adaptation events to address this critical gap. We relate ecological aspects of mutualistic community stability to the stability of persistent evolutionary pathways. Our findings highlight the significance of the structural stability of ecological systems in predicting biodiversity loss under both evolutionary and environmental changes, particularly in relation to species-level selection. Notably, our simulations reveal that the evolution of mutualistic networks tends to increase a network-dependent parameter termed critical competition, which places systems in a regime in which mutualistic interactions enhance structural stability and, consequently, biodiversity.\u0000This research emphasizes the pivotal role of natural selection in shaping ecological networks, steering them towards reduced effective competition below a critical threshold where mutualistic interactions foster stability. The outcomes of our study contribute to the development of a predictive framework for eco-evolutionary dynamics, offering insights into the interplay between ecological and evolutionary processes in the face of environmental change.","PeriodicalId":501320,"journal":{"name":"bioRxiv - Ecology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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