Ecology最新文献

{"title":"Functional R code is rare in species distribution and abundance papers","authors":"Kenneth F. Kellner, Jeffrey W. Doser, Jerrold L. Belant","doi":"10.1002/ecy.4475","DOIUrl":"https://doi.org/10.1002/ecy.4475","url":null,"abstract":"Analytic reproducibility is important for scientific credibility in ecology, but the extent to which scientific literature meets this criterion is not well understood. We surveyed 497 papers published in 2018–2022 in 9 ecology‐related journals. We focused on papers that used hierarchical models to estimate species distribution and abundance. We determined if papers achieved two components of analytic reproducibility: (1) availability of data and code, and (2) code functionality. We found that 28% of papers made data and code available, and 7% of papers provided code that ran without errors. Our findings indicate that analytic reproducibility remains the exception rather than the rule in ecology literature. We recommend authors (1) test code in a separate clean environment; (2) simplify code structure; (3) minimize software packages used; and (4) minimize code run time. We suggest journals (1) validate authors' provided open data statements and URLs; (2) recommend that code and data be shared in a separate repository rather than as appendices; and (3) elevate the status of code and data during review. We suggest these guidelines can aid the ecology community by improving the scientific reproducibility and credibility of ecological research.","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"54 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiyear genotype characterization of eastern spruce budworm outbreaking populations from Quebec and adjacent regions","authors":"João Pedro Fontenelle, Jeremy Larroque, Simon Legault, Julian Wittische, Jessica A. R. Underwood, Patrick M. A. James","doi":"10.1002/ecy.4466","DOIUrl":"10.1002/ecy.4466","url":null,"abstract":"<p>Population outbreaks are characterized by irruptive changes in population density and connectivity resulting in rapid demographic and spatial expansion, often at the landscape scale. Outbreaks are common across multiple taxa, many of which inhabit northern ecosystems. Outbreaks of Lepidopteran defoliators in forest ecosystems are a particularly compelling example of this phenomenon, given the massive spatial scales over which these outbreaks can occur, their frequency, and socioeconomic impacts. The eastern spruce budworm (SBW) is a native outbreaking Lepidopteran defoliator of North American boreal forests. Cyclic outbreaks of the SBW influence ecosystem functioning and resilience, as well as forest productivity, timber supply, and other socioeconomic values related to management and mitigation. Despite these significant impacts, the ecological and biological drivers and outcomes of these outbreaks remain poorly understood. Here, we present an extensive genotypic dataset for 1998 geo-referenced SBW individuals collected between the years of 2012 and 2017, during the rising and peak phases of an outbreak that began approximately in 2006. Our sampling covers an unprecedented scope in the extent and number of individuals collected between 2012 and 2017 from Quebec, and in 2015 from New Brunswick (Canada) and from Maine (USA), from multiple SBW life stages, including early and late instar larvae (L2–L6), pupae, and adult moths. Genomic DNA extraction was followed by library preparation and high-throughput sequencing using Genotyping-by-Sequencing (GBS). Samples were genotyped for single nucleotide polymorphisms (SNPs) and aligned to the bw6 version of the SBW genome. This dataset represents one of the most extensive genotypic datasets to date for a boreal insect and is unique as it includes multiple years during a developing (ongoing, at time of sampling) outbreak. Sampling effort covered areas close to the epicenter of the outbreak (Quebec/Canada) and adjacent areas affected by the outbreak progress. This dataset also provides genome-wide characterization of SBW populations from Quebec, serving as a standard for the identification of future samples regarding their locality of origin, structure and connectivity. These data represent a valuable novel resource for further study of the spatial and temporal dynamics of SBW, and how spatial genetic diversity and gene flow are affected by population outbreaks. These data provide a temporal snapshot of SBW genetic diversity, which can serve as baseline for future studies regarding outbreaks, and the impact of human-induced environmental changes on complex population dynamics. This genotype dataset comprises a unique representation of genomic-level composition and variation observed in subsequent generations of an irruptive, cyclic outbreaking species and is of utmost importance for exploring and describing how accelerated demographic variation impacts the development of spatial genetic structure across ","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"105 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecy.4466","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142669895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resting in plain sight: Dormancy ecology of the intermediate snail host of Schistosoma haematobium","authors":"Naima C. Starkloff, Moses P. Mahalila, Safari Kinung'hi, David J. Civitello","doi":"10.1002/ecy.4472","DOIUrl":"10.1002/ecy.4472","url":null,"abstract":"<p>In rural northwestern Tanzania, land-use change to increase agricultural water availability has resulted in networks of rain catchment ponds teeming with snails that transmit <i>Schistosoma haematobium</i>, a parasitic worm causing urinary schistosomiasis in humans. These aquatic snails (<i>Bulinus nasutus</i>), however, must endure seasonal droughts that transform lush, nutrient-filled habitat to barren, parched earth for up to seven months yearly. The return of rain in the wet season is followed rapidly by the reappearance of abundant snail populations. The mystery of <i>how</i> snails endure the persistent harsh elements of long dry seasons is well described by severely decreased metabolism and other physiological adaptations that underlie the behavior of aestivation (periodic dormancy due to decreased moisture in a habitat, i.e., “dry season hibernation”), which is common in snails (Brown, <span>1994</span>). The lack of knowledge of <i>where</i> snails aestivate has largely halted the study of schistosomiasis-transmitting snail dormancy in the last half century, even though successful dormancy could drive snail population dynamics and consequently, schistosome disease outcomes for humans.</p><p>Only a single publication, to our knowledge, has identified aestivating <i>B. nasutus</i> in the field, describing the typical locality as <2 cm below the soil and in the pond outer periphery (Webbe, <span>1962</span>), but they did not provide standard survey protocols. Following the standardized methods for another <i>Bulinus</i> species (Betterton et al., <span>1988</span>), we dug 2–5 cm transects or quadrats into nine dry agricultural ponds outside of Mwanza, Tanzania, searching for the locality of dormant snails in September and October 2022. We opportunistically searched 10 additional dry and nearly dry ponds for aestivating snails in drying vegetation and mud. But across these 19 different ponds, we observed only a single snail which then survived in the lab for over 30 days. We also found many desiccated shells in the landscape. We realized why scientists had largely ignored this behavior for the last half century: Dormant snails seemed well shielded from the elements, including curious scientists. Considering the duration of the dry period and its potential disease implications, however, we were determined to better characterize the dormancy ecology of <i>B. nasutus</i>.</p><p>In mid-2023, we began a small-scale dormancy experiment at the National Institute for Medical Research, Mwanza. We measured survival rates in four basins (two for one month of dormancy, two for two months of dormancy), each containing soil and 20 <i>B. nasutus</i> snails collected from active agricultural ponds. Within each dormancy period, basins contained either schistosome-infected or -uninfected snails. What we did not expect was that most snails (66.25%) did not burrow below the soil but instead remained on the surface throughout dormancy (Figure 1). We assu","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"105 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecy.4472","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Canids as pollinators? Nectar foraging by Ethiopian wolves may contribute to the pollination of Kniphofia foliosa","authors":"Sandra Lai, Don-Jean Léandri-Breton, Adrien Lesaffre, Abdi Samune, Jorgelina Marino, Claudio Sillero-Zubiri","doi":"10.1002/ecy.4470","DOIUrl":"10.1002/ecy.4470","url":null,"abstract":"<p>Up to 87% of flowering plant species depend on a wide range of animal species for their pollination (Ollerton et al., <span>2011</span>). Among mammals, nectivorous pollinator species are principally represented by flying species such as bats and, to a smaller extent, by some marsupials, rodents, primates, and small carnivores (Carthew & Goldingay, <span>1997</span>; Regan et al., <span>2015</span>). It has been pointed out that therophily, pollination by non-flying mammals, may however be more widespread and hold more significance than currently recognized (Carthew & Goldingay, <span>1997</span>; Goldingay et al., <span>1991</span>). For example, in Australia, direct experimentation has shown that the brown antechinus (<i>Antechinus stuartii</i>) and the sugar glider (<i>Petaurus breviceps</i>) are important pollinators of native Proteaceae (<i>Banksia</i> spp.) (Goldingay et al., <span>1991</span>). The mammals involved in pollination are typically small- to medium-sized and often arboreal species, whereas nectar-feeding carnivoran mammals are much rarer, with only four species of Carnivora among the 343 mammals identified as potential and known pollinators in a 2015 review (Regan et al., <span>2015</span>). However, examples of carnivore species foraging for nectar, and putatively involved in pollination, continue to be discovered, such as the masked palm civet (<i>Paguma larvata</i>), the Cape genet (<i>Genetta tigrina</i>), and the Cape gray mongoose (<i>Herpestes pulverulenta</i>) (Kobayashi et al., <span>2019</span>; Steenhuisen et al., <span>2015</span>). Here, we report the visitation to inflorescences of the Ethiopian red hot poker (<i>Kniphofia foliosa</i>) by a large carnivore, the Ethiopian wolf (<i>Canis simensis</i>), in the Bale Mountains of southern Ethiopia. Wolves were observed foraging for nectar on <i>K. foliosa</i> flowers, which deposited relatively large amount of pollen on their muzzles, suggesting they could contribute to pollination (Figure 1).</p><p><i>Kniphofia foliosa</i> (Asphodelaceae) is a perennial herb endemic to Ethiopia found in the Bale Mountains and other high altitude grasslands (Demissew & Nordal, <span>2010</span>), which also host the endemic Ethiopian wolf, a top predator restricted to the Afroalpine ecosystem (Marino, <span>2003</span>). Flowers from the <i>Kniphofia</i> genus produce large amounts of nectar, which attracts a variety of bird and insect pollinators (Brown et al., <span>2009</span>, <span>2010</span>). The nectar-feeding behavior of wolves on <i>K. foliosa</i> flowers during the main blooming season (June–November; Dagnachew et al., <span>2022</span>) has been opportunistically but repeatedly observed by the authors over many years. To further detail this behavior, we followed six different wolves foraging on <i>K. foliosa</i> inflorescences over four consecutive days in late May-early June 2023. The observed individuals were one subadult male (<2 years old), four adult","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"105 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecy.4470","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phenological mismatch is less important than total nectar availability for checkerspot butterflies","authors":"Elizabeth E. Crone,&nbsp;June V. Arriens,&nbsp;Leone M. Brown","doi":"10.1002/ecy.4461","DOIUrl":"10.1002/ecy.4461","url":null,"abstract":"<p>Changes in phenology are a conspicuous fingerprint of climate change, leading to fears that phenological mismatches among interacting species will be a leading cause of population declines and extinction. We used quantile regression to analyze museum collection data and estimate changes in the phenological overlap of Baltimore checkerspot butterflies and 12 common nectar plant species over several decades in two geographic regions. We combined these museum data with field estimates of each species' flower density and nectar sugar production to estimate changes in resource availability caused by shifts in phenological overlap. Phenological overlap (measured as the proportion of plant flowering during the flight period of an average butterfly) decreased through time, primarily because the flowering period of nectar plants was longer, but the flight period of butterflies was shorter in recent years. Our study was also motivated by the hypothesis that phenological mismatches may be more severe in the southern region due to a midsummer dearth in floral resources, but this hypothesis was not supported by our data. Although phenological overlap was somewhat smaller in the southern region, changes in overlap through time were similar in both regions. When phenological overlap was weighted by nectar sugar production of different species, the overlap increased in the southern region but decreased in the northern region (the opposite of our prediction). Overall, nectar resources were much more abundant at study sites in our northern region than in our southern region, possibly due to differences in land management. Our study demonstrates the complexities of phenological mismatch of interacting species and highlights that phenological changes may have small impacts on population viability.</p>","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"105 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecy.4461","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A modeling approach to forecast local demographic trends in metapopulations","authors":"Thierry Chambert,&nbsp;Christophe Barbraud,&nbsp;Emmanuelle Cam,&nbsp;Antoine Chabrolle,&nbsp;Nicolas Sadoul,&nbsp;Aurélien Besnard","doi":"10.1002/ecy.4459","DOIUrl":"10.1002/ecy.4459","url":null,"abstract":"<p>Predicting animal population trajectories into the future has become a central exercise in both applied and fundamental ecology. Because demographic models classically assume population closure, they tend to provide inaccurate predictions when applied locally to interconnected subpopulations that are part of a larger metapopulation. Ideally, one should explicitly model dispersal among subpopulations, but in practice this is prevented by the difficulty of estimating dispersal rates in the wild. To forecast the local demography of connected subpopulations, we developed a new demographic model (hereafter, the two-scale model) that disentangles two processes occurring at different spatial scales. First, at the larger scale, a closed population model describes changes in metapopulation size over time. Second, total metapopulation size is redistributed among subpopulations, using time-varying proportionality parameters. This two-step approach ensures that the long-term growth of every subpopulation is constrained by the overall metapopulation growth rate. It implicitly accounts for the interconnectedness among subpopulations and avoids unrealistic trajectories. Using realistic simulations, we compared the performance of this new model with that of a classical closed population model at predicting subpopulations' trajectories over 30 years. While the classical model predicted future subpopulation sizes with an average bias of 30% and produced predictive errors sometimes &gt;500%, the two-scale model showed very little bias (&lt;3%) and never produced predictive errors &gt;20%. We also applied both models to a real dataset on European shags (<i>Gulosus aristotelis</i>) breeding along the Atlantic coast of France. Again, the classical model predicted highly unrealistic growths, as large as a 200-fold increase over 30 years for some subpopulations. The two-scale model predicted very sensible growths, never larger than a threefold increase over the 30-year time horizon, which is more in accordance with this species' life history. This two-scale model provides an effective solution to forecast the local demography of connected subpopulations in the absence of data on dispersal rates. In this context, it is a better alternative than closed population models and a more parsimonious option than full-dispersal models. Because the only data required are simple counts, this model could be useful to many large-scale wildlife monitoring programs.</p>","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"105 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecy.4459","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Joint inference for telemetry and spatial survey data","authors":"Paul G. Blackwell,&nbsp;Jason Matthiopoulos","doi":"10.1002/ecy.4457","DOIUrl":"10.1002/ecy.4457","url":null,"abstract":"<p>Data integration, the joint statistical analysis of data from different observation platforms, is pivotal for data-hungry disciplines such as spatial ecology. Pooled data types obtained from the same underlying process, analyzed jointly, can improve both precision and accuracy in models of species distributions and species–habitat associations. However, the integration of telemetry and spatial survey data has proved elusive because of the fundamentally different analytical approaches required by these two data types. Here, “spatial survey” denotes a survey that records spatial locations and has no temporal structure, for example, line or point transects but not capture–recapture or telemetry. Step selection functions (SSFs—the canonical framework for telemetry) and habitat selection functions (HSFs—the default approach to spatial surveys) differ in not only their specifications but also their results. By imposing the constraint that microscopic mechanisms (animal movement) must correctly scale up to macroscopic emergence (population distributions), a relationship can be written between SSFs and HSFs, leading to a joint likelihood using both datasets. We implement this approach using maximum likelihood, explore its estimation precision by systematic simulation, and seek to derive broad guidelines for effort allocation in the field. We find that complementarities in spatial coverage and resolution between telemetry and survey data often lead to marked inferential improvements in joint analyses over those using either data type alone. The optimal allocation of effort between the two methods (or the choice between them, if only one can be selected) depends on the overall effort expended and the pattern of environmental heterogeneity. Examining inferential performance over a broad range of scenarios for the relative cost between the two methods, we find that integrated analysis usually offers higher precision. Our methodological work shows how to integrate the analysis of telemetry and spatial survey data under a novel joint likelihood function, using traditional computational methods. Our simulation experiments suggest that even when the relative costs of the two methods favor the deployment of one field approach over another, their joint use is broadly preferable. Therefore, joint analysis of the two key methods used in spatial ecology is not only possible but also computationally efficient and statistically more powerful.</p>","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"105 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecy.4457","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142549665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mesopredator release moderates trophic control of plant biomass in a Georgia salt marsh","authors":"Joseph P. Morton,&nbsp;Marc J. S. Hensel,&nbsp;David S. DeLaMater,&nbsp;Christine Angelini,&nbsp;Rebecca L. Atkins,&nbsp;Kimberly D. Prince,&nbsp;Sydney L. Williams,&nbsp;Anjali D. Boyd,&nbsp;Jennifer Parsons,&nbsp;Emlyn J. Resetarits,&nbsp;Carter S. Smith,&nbsp;Stephanie Valdez,&nbsp;Evan Monnet,&nbsp;Roxanne Farhan,&nbsp;Courtney Mobilian,&nbsp;Julianna Renzi,&nbsp;Dontrece Smith,&nbsp;Christopher Craft,&nbsp;James E. Byers,&nbsp;Merryl Alber,&nbsp;Steven C. Pennings,&nbsp;Brian R. Silliman","doi":"10.1002/ecy.4452","DOIUrl":"10.1002/ecy.4452","url":null,"abstract":"<p>Predators regulate communities through top-down control in many ecosystems. Because most studies of top-down control last less than a year and focus on only a subset of the community, they may miss predator effects that manifest at longer timescales or across whole food webs. In southeastern US salt marshes, short-term and small-scale experiments indicate that nektonic predators (e.g., blue crab, fish, terrapins) facilitate the foundational grass, <i>Spartina alterniflora</i>, by consuming herbivorous snails and crabs. To test both how nekton affect marsh processes when the entire animal community is present, and how prior results scale over time, we conducted a 3-year nekton exclusion experiment in a Georgia salt marsh using replicated 19.6 m² plots. Our nekton exclusions increased densities of plant-grazing snails and juvenile deposit-feeding fiddler crab and, in Year 2, reduced predation on tethered juvenile snails, indicating that nektonic predators control these key macroinvertebrates. However, in Year 3, densities of mesopredatory benthic mud crabs increased threefold in nekton exclusions, erasing the tethered snails' predation refuge. Nekton exclusion had no effect on <i>Spartina</i> biomass, likely because the observed mesopredator release suppressed grazing snail densities and elevated densities of fiddler crabs, whose burrowing alleviates soil stresses. Structural equation modeling supported the hypotheses that nektonic predators and mesopredators control invertebrate communities, with nektonic predators having stronger total effects on <i>Spartina</i> than mud crabs by controlling densities of species that both suppress (grazers) and facilitate (fiddler crabs) plant growth. These findings highlight that salt marshes can be resilient to multiyear reductions in nektonic predators if mesopredators are present and that multiple pathways of trophic control manifest in different ways over time to mediate community dynamics. These results highlight that larger scale and longer-term experiments can illuminate community dynamics not previously understood, even in well-studied ecosystems such as salt marshes.</p>","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"105 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142523926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of multiple mammalian herbivores and climate on grassland–shrubland transitions in the Chihuahuan Desert","authors":"Kieran J. Andreoni,&nbsp;Brandon T. Bestelmeyer,&nbsp;David C. Lightfoot,&nbsp;Robert L. Schooley","doi":"10.1002/ecy.4460","DOIUrl":"10.1002/ecy.4460","url":null,"abstract":"<p>The replacement of grasses by shrubs or bare ground (xerification) is a primary form of landscape change in drylands globally with consequences for ecosystem services. The potential for wild herbivores to trigger or reinforce shrubland states may be underappreciated, however, and comparative analyses across herbivore taxa are sparse. We sought to clarify the relative effects of domestic cattle, native rodents, native lagomorphs, and exotic African oryx (<i>Oryx gazella</i>) on a Chihuahuan Desert grassland undergoing shrub encroachment. We then asked whether drought periods, wet season precipitation, or interspecific grass–shrub competition modified herbivore effects to alter plant cover, species diversity, or community composition. We established a long-term experiment with hierarchical herbivore exclosure treatments and surveyed plant foliar cover over 25 years. Cover of honey mesquite (<i>Prosopis glandulosa</i>) proliferated, responding primarily to climate, and was unaffected by herbivore treatments. Surprisingly, cattle and African oryx exclusion had only marginal effects on perennial grass cover at their current densities. Native lagomorphs interacted with climate to limit perennial grass cover during wet periods. Native rodents strongly decreased plant diversity, decreased evenness, and altered community composition. Overall, we found no evidence of mammalian herbivores facilitating or inhibiting shrub encroachment, but native small mammals interacting with climate drove dynamics of herbaceous plant communities. Ongoing monitoring will determine whether increased perennial grass cover from exclusion of native lagomorphs and rodents slows the transition to a dense shrubland.</p>","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"105 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecy.4460","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142523913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trade-offs between defense and competitive traits in a planktonic predator–prey system","authors":"Tom Réveillon,&nbsp;Lutz Becks","doi":"10.1002/ecy.4456","DOIUrl":"10.1002/ecy.4456","url":null,"abstract":"<p>Predator–prey interactions are crucial components of populations and communities. Their dynamics depend on the covariation of traits of the interacting organisms, and there is increasing evidence that intraspecific trade-off relationships between defense and competitive traits are important drivers of trophic interactions. However, quantifying the relevant traits forming defense–competitiveness trade-offs and how these traits determine prey and predator fitness remains a major challenge. Here, we conducted feeding and growth experiments to assess multiple traits related to defense and competitiveness in six different strains of the green alga <i>Chlamydomonas reinhardtii</i> exposed to predation by the rotifer <i>Brachionus calyciflorus</i>. We found large differences in defense and competitive traits among prey strains and negative relationships between these traits for multiple trait combinations. Because we compared trait differences among strains whose ancestors evolved previously in controlled environments where selection favored either defense or competitiveness, these negative correlations suggest the presence of a trade-off between defense and competitiveness. These differences in traits and trade-offs translated into differences in prey and predator fitness, demonstrating the importance of intraspecific trade-offs in predicting the outcome of predator–prey interactions.</p>","PeriodicalId":11484,"journal":{"name":"Ecology","volume":"105 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecy.4456","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142523927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}