Ecosphere最新文献

{"title":"The presence of American beech litter can alter the growth response of sugar maple seedlings to drought","authors":"Alexandre Collin,&nbsp;Claudele Ghotsa Mekontchou,&nbsp;Audrey Maheu,&nbsp;Phillipe Nolet,&nbsp;Francesca Sotelo,&nbsp;David Rivest","doi":"10.1002/ecs2.70103","DOIUrl":"https://doi.org/10.1002/ecs2.70103","url":null,"abstract":"<p>In late successional forests of North America, sugar maple (<i>Acer saccharum</i> Marsh.) and American beech (<i>Fagus grandifolia</i> Ehrh.) form a complex ecosystem with intricate interactions. Over the last few decades, several studies have reported a marked increase in American beech dominance relative to sugar maple. Recent evidence suggests that extreme events such as drought could accelerate sugar maple's maladaptation to climate change and favor American beech in its replacement dynamics. In this study, we conducted a greenhouse experiment to investigate the effects of soil water stress and American beech presence on sugar maple seedling growth, structural physiology, leaf nitrogen, and chlorophyll. The seedlings were subjected to the following treatments independently and in combination for 82 days: soil water stress; soil originating from stands with American beech proliferation; soil sterilization; and presence of American beech litter. The results revealed that soil water stress was the primary factor significantly reducing sugar maple seedling growth, which also resulted in an increased root-to-shoot ratio. The presence of soil from stands with American beech proliferation did not exacerbate this negative effect. Soil sterilization, initially expected to reduce seedling growth by eliminating mycorrhizal associations, actually improved seedling growth. This suggests that adverse biotic processes, such as pathogens, were present in the soils regardless of their origin, and their negative effects outweighed the potential benefits from mycorrhization. The addition of American beech litter mitigated the effects of soil water stress but also introduced allelopathic compounds that hindered seedling growth. Overall, this study highlighted the complex interactions affecting sugar maple seedling growth, emphasizing that drought is a major limiting factor.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438832","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}

{"title":"Refining the trophic diversity, network structure, and bottom-up importance of prey groups for temperate reef fishes","authors":"S. Zarco-Perello,&nbsp;S. Bennett,&nbsp;J. Goetze,&nbsp;T. H. Holmes,&nbsp;R. D. Stuart-Smith,&nbsp;E. R. White","doi":"10.1002/ecs2.70193","DOIUrl":"https://doi.org/10.1002/ecs2.70193","url":null,"abstract":"<p>Marine fish communities are highly diverse and contribute significantly to ecosystem processes. However, understanding their specific functional roles and the importance of different prey groups for sustaining fish communities has been limited by the historical classification of fishes into a few coarse trophic guilds. Using diet information to perform a high-resolution trophic classification of 298 temperate reef fish species distributed across south-western Australia, we built metacommunity and subregional trophic networks to evaluate the most important trophic relationships and energy pathways in temperate reefs. We identified 26 specialized trophic guilds within the groups of herbivores, zoobenthivores, zooplanktivores, piscivores, and cleaners. Zoobenthivorous fishes had the highest species richness and trophic diversity with 191 species in nine guilds. Consumers of crustaceans showed greater species redundancy at the metacommunity level. In contrast, a low redundancy of echinodermivores could represent a risk to local capacity for top-down control of sea urchins across the region. Finer scale analysis of prey at the family level showed that piscivorous guilds may influence different trophic pathways, with some guilds consuming other piscivorous fishes, while others consume lower trophic levels, particularly crustaceavores. Evidence of predation on herbivorous guilds was only found for turf grazers, suggesting that fish herbivory might not function as a major direct link between primary producers and higher trophic levels. Among the prey consumed by fishes, micro-crustaceans and decapods accounted for 33% of all diet proportions. The importance of macrophytes to the fish community likely resides indirectly through the trophic pathway of herbivorous and detritivorous invertebrates, particularly crustaceans, which are more consumed by fishes than macrophytes themselves. Comparison of trophic networks in the region showed that warmer locations had higher species redundancy per node and higher strength in trophic interactions. Yet, all networks had structural properties consistent with the meta-network regarding the importance of prey groups and modularity. Considering high-resolution predator–prey interactions enhances our understanding of the blue-print of ecosystem functions in shallow marine systems. Identifying the specific trophic significance of different consumers and prey groups is important for ecological forecasting and the prioritization of conservation and resource management regulations in our current fast-changing world.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70193","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431501","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}

{"title":"Deciphering the spectra of flowers to map landscape-scale blooming dynamics","authors":"Yoseline Angel,&nbsp;Ann Raiho,&nbsp;Dhruva Kathuria,&nbsp;K. Dana Chadwick,&nbsp;Philip G. Brodrick,&nbsp;Evan Lang,&nbsp;Francisco Ochoa,&nbsp;Alexey N. Shiklomanov","doi":"10.1002/ecs2.70127","DOIUrl":"https://doi.org/10.1002/ecs2.70127","url":null,"abstract":"<p>Like leaves, floral coloration is driven by inherent optical properties, which are determined by pigments, scattering structure, and thickness. However, establishing the relative contribution of these factors to canopy spectral signals is usually limited to in situ observations. Modeling flowering dynamics (e.g., blooming duration, spatial distribution) at the landscape scale may reveal insights into ecological processes and phenological adaptations to environmental changes. Multi-temporal visible to shortwave infrared (VSWIR) imaging spectroscopy observations are especially suited for such efforts. Reflectance in this spectral range is sensitive to major flower pigments, flowering phenology traces, and biophysical differences between flowers and other plant parts. We explored how flowers contribute to spectral signals using a time series of imagery from the Airborne Visible InfraRed Imaging Spectrometer-Next Generation (AVIRIS-NG) collected as part of the Surface Biology and Geology (SBG) High-Frequency Time Series (SHIFT) campaign as a case study. Airborne data were collected weekly during the spring of 2022 across two natural reserves in California. Field spectra were gathered from blooming plots at leaf, flower, and canopy levels at two time points during the campaign. The processed data were used to investigate flowering species' spectro-temporal variation and spatial distribution using spectral mixture residual (SMR), Gaussian clustering techniques, and a proposed narrow-band flowering index. Linear spectral unmixing allowed the computation of the weighted contribution of four major high-variance endmembers (leaves, flowers, soil, and dark) and low-variance residual signal that comprises subtle spectral features used to track biophysical processes. The reflectance residual was projected on a low principal component basis to characterize flowering clusters' variation and spatial distribution based on the Gaussian mixture model, providing an uncertainty metric to assess the results. Mapping flowering events from modeling spectro-temporal dynamics throughout the season, from pre-blooming to post-flowering stages, allowed us to identify gradient variations in spectral features within the VSWIR spectral range linked to flowering pigments. Time series of the Mixture Residual Blooming Index and the Red-Edge Normalized Difference Vegetation Index revealed specific flowering and greenness phenophases across the two main species (<i>Coreopsis gigantea</i>, <i>Artemisia californica</i>) in the flowering areas. Overall, our approach opens opportunities for future satellite monitoring of floral cycles at broader scales.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70127","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424005","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}

{"title":"An accurate and efficient semiautomated approach to counting birds: Estimating Northern Gannet colony size in Canada","authors":"Jacob Walker,&nbsp;Trevor S. Avery,&nbsp;Francis St-Pierre,&nbsp;Jean-François Rail,&nbsp;Danielle E. A. Quinn,&nbsp;Matthew English,&nbsp;Stephanie Avery-Gomm","doi":"10.1002/ecs2.70183","DOIUrl":"https://doi.org/10.1002/ecs2.70183","url":null,"abstract":"<p>Improving the efficiency of population monitoring and conservation programs is beneficial, so long as the accuracy of the information collected is not diminished. The need to expeditiously estimate the population size of seabird colonies is especially acute during mass mortality events when aerial surveys can provide information quickly on the extent of effects and total mortality. In 2022, the highly pathogenic avian influenza virus caused outbreaks at most Northern Gannet <i>Morus bassanus</i> colonies worldwide, killing tens of thousands of gannets in eastern Canada. In this study, we evaluated the accuracy and efficiency of a semiautomated method using the free software CountEm for counting Northern Gannet nests by reanalyzing 13 years of aerial photographs from past population surveys (2009–2020 and 2022). The CountEm program uses a geometric sampling method which overlays a grid of quadrats onto photographs in which the user counts objects of interest. We developed a protocol that generated population estimates that are accurate enough to support population management objectives (i.e., within 2%–5% of manual counts) and outline additional ways to improve CountEm accuracy. Additionally, using CountEm was 1100% more efficient than manually counting based on counting time. Since CountEm relies on human identification of objects to be counted, our methods, results, and conclusions are transferable to any taxa that form large aggregations and can be identified and counted in photographs.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70183","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424006","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}

{"title":"Reassembly of a tropical rainforest: A new chronosequence in the Chocó tested with the recovery of tree attributes","authors":"Sebastián Escobar,&nbsp;Felicity L. Newell,&nbsp;María-José Endara,&nbsp;Juan E. Guevara-Andino,&nbsp;Anna R. Landim,&nbsp;Eike Lena Neuschulz,&nbsp;Ronja Hausmann,&nbsp;Jörg Müller,&nbsp;Karen M. Pedersen,&nbsp;Matthias Schleuning,&nbsp;Constance J. Tremlett,&nbsp;Edith Villa-Galaviz,&nbsp;H. Martin Schaefer,&nbsp;David A. Donoso,&nbsp;Nico Blüthgen","doi":"10.1002/ecs2.70157","DOIUrl":"https://doi.org/10.1002/ecs2.70157","url":null,"abstract":"<p>From hunting and foraging to clearing land for agriculture, humans modify forest biodiversity, landscapes, and climate. Forests constantly undergo disturbance–recovery dynamics, and understanding them is a major objective of ecologists and conservationists. Chronosequences are a useful tool for understanding global restoration efforts. They represent a space-for-time substitution approach suited for the quantification of the <i>resistance</i> of ecosystem properties to withstand disturbance and the <i>resilience</i> of these properties until reaching pre-disturbance levels. Here, we introduce a newly established chronosequence with 62 plots in active cacao plantations and pastures, early and late regeneration, and old-growth forests in the extremely wet Chocó rainforest. Plots were located across a 200-km² area, with a total area of 95 km² within a 1-km radius. Our chronosequence covers the largest total area of plots compared with others in the Neotropics with 15.5 ha. Plots ranged from 159 to 615 m above sea level in a forested landscape with 74% ± 2.8% forest cover within a 1-km radius including substantial old-growth forest cover. Land-use legacy and regeneration time were not confounded by elevation. We tested how six forest structure variables (maximum tree height and dbh, basal area, number of stems, vertical vegetation heterogeneity, and light availability), aboveground biomass (AGB), and rarefied tree species richness change along our chronosequence. Forest structure variables, AGB, and tree species richness increased with regeneration time and are predicted to reach similar levels to those in old-growth forests. Compared with previous work in the Neotropics, old-growth forests in Canandé accumulate high AGB that takes one of the largest time spans reported until total recovery. Our chronosequence comprises one of the largest tree species pools, covers the largest total area of regenerating and old-growth forests, and has higher forest cover than other Neotropical chronosequences. Hence, our chronosequence can be used to determine the time for recovery and stability (resistance and resilience) of different taxa and ecosystem functions, including species interaction networks. This integrative effort will ultimately help to understand how one of the most diverse forests on the planet recovers from large-scale disturbances.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70157","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423616","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}

{"title":"Participatory surveillance reveals marsh deer mortality event during an extraordinary flood in Ibera Wetlands, Argentina","authors":"M. M. Orozco,&nbsp;E. C. Guillemi,&nbsp;L. Minatel,&nbsp;A. Schapira,&nbsp;K. Caimi,&nbsp;Y. Berra,&nbsp;P. Blanco,&nbsp;D. Di Nucci,&nbsp;M. D. Farber,&nbsp;M. Pilar Fernández,&nbsp;H. D. Argibay","doi":"10.1002/ecs2.70186","DOIUrl":"https://doi.org/10.1002/ecs2.70186","url":null,"abstract":"<p>Mortality events of marsh deer (<i>Blastocerus dichotomus</i>) have been historically described in the southern margins of its geographical range. Few documented cases show how environmental changes and pathogens interact to trigger mortality scenarios and reveal their causes. Here, using a participatory surveillance framework, we document the most extensive marsh deer mortality event observed in the last three decades occurring in Ibera ecoregion, Corrientes, Argentina. Local stakeholders monitored marsh deer disease cases or mortality, and upon detection, emergency response teams conducted extensive field studies, documenting 409 dead marsh deer between May and August 2017. Complete postmortem examinations were performed on 16 deer, revealing hepatic fibrosis associates with <i>Fasciola hepatica</i> and multiple parasite infestations in different tissues. Molecular analysis performed on samples from 82 deer identified parasitic and vector-borne microorganisms, including <i>Anaplasma marginale</i>, <i>Theileria cervi</i>, and <i>Trypanosoma</i> spp. High-tick burden and <i>Trypanosoma</i> spp. were significantly associated with deficient body condition. Concurrently, increased precipitation and watershed height significantly expanded flooded areas, with reduced herbaceous cover indicated by land cover analysis. Our findings suggest that prolonged flooding in Ibera played a critical role in the interactions between habitat availability, marsh deer, and parasites. Environmental stressors likely exacerbated the effects of parasitic infections, highlighting the importance of integrating environmental monitoring with wildlife health assessments. Our results contribute to scientific knowledge that provides tools to enhance management efforts focused on protecting the marsh deer population and its critical habitats.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70186","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431500","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}

{"title":"Influence of melatonin on the successful infection of Daphnia dentifera by Metschnikowia bicuspidata","authors":"Ashley G. Hughes,&nbsp;Jeannette E. Cullum,&nbsp;Molly J. Fredericks,&nbsp;Patrick J. Wilson,&nbsp;Anke Schwarzenberger,&nbsp;Carla E. Cáceres","doi":"10.1002/ecs2.70192","DOIUrl":"https://doi.org/10.1002/ecs2.70192","url":null,"abstract":"<p>The levels of the hormone melatonin fluctuate daily, with higher concentrations often found at night. These fluctuations likely influence multiple aspects of physiology, including the immune response. We demonstrated that the addition of exogenous melatonin increased the proportion of the freshwater zooplankton <i>Daphnia dentifera</i> that became infected by the fungal pathogen <i>Metschnikowia bicuspidata</i>, during the day but not at night. To determine the stage of this host–pathogen interaction at which melatonin may increase susceptibility, we conducted a series of laboratory experiments in which we raised <i>Daphnia</i> in the presence and absence of exogenous melatonin. To complete its life cycle, <i>Metschnikowia</i> must encounter a foraging host, overcome the host's barrier resistance (gut wall), and evade the host's immune response (internal clearance). We quantified encounter rate by measuring the gut passage time and the number of spores that entered the gut. We also measured the number of spores that successfully entered the body cavity (barrier resistance) and the hemocyte response to spores entering the body cavity (one metric of internal clearance). Finally, we quantified the effect of exogenous melatonin on triggering molting. The addition of exogenous melatonin lengthened gut passage time and decreased the number of spores present in the gut. We found no effect of melatonin on the percentage of gut spores successfully entering the host's body cavity, nor on the hemocyte response. Melatonin is known to influence the timing of molting and hosts that molted during exposure were more likely to become infected, likely due to a decrease in barrier resistance. In a fully factorial experiment, there was a high death rate, low infection rate, and therefore no discernible effect of melatonin on molting, nor molting or melatonin on infection. Our results provide insight into the stages of infection where melatonin does and does not have significant effects.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70192","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431579","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}

{"title":"New insights into the Scolytus multistriatus, Geosmithia spp., and Ophiostoma novo-ulmi association","authors":"Alessia L. Pepori,&nbsp;Nicola Luchi,&nbsp;Francesco Pecori,&nbsp;Massimo Faccoli,&nbsp;Alberto Santini","doi":"10.1002/ecs2.70145","DOIUrl":"https://doi.org/10.1002/ecs2.70145","url":null,"abstract":"<p>Dutch elm disease (DED) is a destructive tracheomycosis caused by <i>Ophiostoma novo-ulmi</i>, an ascomycete that is devastating natural elm populations throughout Europe, North America, and part of Asia. The fungus is mainly spread by elm bark beetles (EBBs) (Coleoptera: Curculionidae, Scolytinae) that complete their life cycle between healthy and diseased elms. It has recently been shown that certain fungi of the genus <i>Geosmithia</i>, vectored by bark beetles, are involved in the DED pathosystem. Not only it has been observed that the two fungi share the same habitat in the host plant and during each developmental stage of the insect, but also there appears to be a parasitic association between them. By analyzing the presence and quantity of the two fungi on the bodies of elm beetles by a qPCR duplex TaqMan assay, this work aimed to explore the dynamic of the relationship among the adults of <i>Scolytus multistriatus</i>, <i>O. novo-ulmi</i>, and <i>Geosmithia</i> spp. at sites characterized by different DED severity levels during the elm growing season. We observed that, regardless of the epidemiological conditions, both fungi are always present on adult flickering insects. The proportion of the two fungal populations varies among sampling sites, with <i>Geosmithia</i> spp. being predominant in the non-epidemic sites. The hyperparasitism of <i>Geosmithia</i> toward <i>O. novo-ulmi</i> within this tri-trophic system should be investigated further for potential use as biological control agent.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70145","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143389026","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}

{"title":"Consumer- and seaweed-specific impacts of invasion-mediated changes to detrital subsidies on rocky shores","authors":"Ricardo DeSantiago,&nbsp;Wendi K. White,&nbsp;John R. Hyde,&nbsp;Katherine M. Swiney,&nbsp;Jeremy D. Long","doi":"10.1002/ecs2.70165","DOIUrl":"https://doi.org/10.1002/ecs2.70165","url":null,"abstract":"<p>Detrital subsidies such as leaf litter, animal carcasses, and marine wrack can profoundly shape recipient habitats by influencing resiliency and productivity. Species introductions and climate-driven range shifts alter the quantity and quality of these subsidies in donor habitats, thereby potentially influencing recipient communities. Such impacts might be particularly important when detrital shifts alter detritivore feeding and performance. Attempts to identify a general theory predicting the consequences of invasive species on detritivores have been challenging, in part because most theories have been based on the study of microbes or consumers of living prey. Further, two recent meta-analyses disagree about the impacts of invasive plants on detritivore populations. Here, we examined the potential impact of a human-mediated shift in macroalgal detrital subsidy from native giant kelp (<i>Macrocystis pyrifera</i>) to invasive devilweed (<i>Sargassum horneri</i>) on recipient rocky shores, with an emphasis on exploring species-specific impacts. We assessed consumer performance on single species diets or on a mixture in no-choice assays, and we assessed feeding preference in choice assays. Additionally, we examined the impacts of this shift on grazing of native benthic seaweeds by an intertidal consumer assemblage. Replacing native <i>Macrocystis</i> with invasive <i>Sargassum</i> had consumer-specific impacts on performance—suppressing growth of red abalone (<i>Haliotis rufescens</i>) but enhancing growth of black turban snails (<i>Tegula funebralis</i>). The effect of mixed diets on consumer growth also displayed consumer specificity. Also, replacing <i>Macrocystis</i> with invasive <i>Sargassum</i> increased grazing of native benthic seaweeds by a realistic detritivore assemblage, but only on the habitat-forming brown seaweed, <i>Silvetia compressa</i>. Thus, invasion-mediated changes in detrital wrack composition had consumer- and seaweed-specific impacts. Such species specificity could underlie disagreements about the impact of species invasions on detritivore populations and could impede our ability to identify a general theory about how species invasions will impact recipient communities via detrital pathways.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70165","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143389027","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}

{"title":"Associating cultivars or species with complementary traits is key for enhancing aphid control through bottom-up effects","authors":"Alba Tous-Fandos,&nbsp;Lourdes Chamorro-Lorenzo,&nbsp;Berta Caballero-López,&nbsp;José M. Blanco-Moreno,&nbsp;Daniel Bragg,&nbsp;Alice Casiraghi,&nbsp;Alejandro Pérez-Ferrer,&nbsp;F. Xavier Sans","doi":"10.1002/ecs2.70076","DOIUrl":"https://doi.org/10.1002/ecs2.70076","url":null,"abstract":"<p>Organic farming promotes diversification strategies to enhance ecological functions. However, early field studies suggested that not all cereal polycultures confer benefits in terms of pest control. Our research involved a trait-based field study to evaluate the advantages of different wheat polycultures on aphid control and yield. We also explored the bottom-up and top-down effects underlying aphid control. We established 10 treatments replicated in five organic fields: three wheat monocultures (Florence-Aurora [FA], Montcada [MO], and Forment [FO]), a mixture with similar-traits cultivars (FAMO), and a mixture with different-traits cultivars (FAFO), each duplicated with and without a burclover undersowing. We analyzed aphid abundance, number of aphids per tiller, parasitism rate, predatory arthropods' abundance, and crop yield. FAFO and burclover undersowing significantly lowered aphid abundance and the number of aphids per tiller on FA. However, the treatments did not affect the abundance of predators or parasitism rates. Finally, wheat yield was similar across treatments, except in 2021 season when FA yielded significantly less. Our findings suggest that polycultures' benefits on aphid control are cultivar specific. Mixing wheat cultivars with complementary functional traits (height and odor profile) and the association of wheat monoculture with a burclover undersowing enhances aphid control by bottom-up effects without compromising crop yield. Nevertheless, stacking the cultivar mixtures with burclover undersowing did not outperform the results of a single diversity practices, probably because of functional redundancy of resistant cultivars and burclover cover.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":"16 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70076","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143380437","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}