| 1. |
- Hyndes, G. A., et al.
(författare)
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The role of inputs of marine wrack and carrion in sandy-beach ecosystems: a global review
- 2022
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Ingår i: Biological Reviews Cambridge Philosophical Society. - : Wiley. - 1464-7931 .- 1469-185X. ; 97:6, s. 2127-61
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Forskningsöversikt (refereegranskat)abstract
- Sandy beaches are iconic interfaces that functionally link the ocean with the land via the flow of organic matter from the sea. These cross-ecosystem fluxes often comprise uprooted seagrass and dislodged macroalgae that can form substantial accumulations of detritus, termed 'wrack', on sandy beaches. In addition, the tissue of the carcasses of marine animals that regularly wash up on beaches form a rich food source ('carrion') for a diversity of scavenging animals. Here, we provide a global review of how wrack and carrion provide spatial subsidies that shape the structure and functioning of sandy-beach ecosystems (sandy beaches and adjacent surf zones), which typically have little in situ primary production. We also examine the spatial scaling of the influence of these processes across the broader land- and seascape, and identify key gaps in our knowledge to guide future research directions and priorities. Large quantities of detrital kelp and seagrass can flow into sandy-beach ecosystems, where microbial decomposers and animals process it. The rates of wrack supply and its retention are influenced by the oceanographic processes that transport it, the geomorphology and landscape context of the recipient beaches, and the condition, life history and morphological characteristics of the macrophyte taxa that are the ultimate source of wrack. When retained in beach ecosystems, wrack often creates hotspots of microbial metabolism, secondary productivity, biodiversity, and nutrient remineralization. Nutrients are produced during wrack breakdown, and these can return to coastal waters in surface flows (swash) and aquifers discharging into the subtidal surf. Beach-cast kelp often plays a key trophic role, being an abundant and preferred food source for mobile, semi-aquatic invertebrates that channel imported algal matter to predatory invertebrates, fish, and birds. The role of beach-cast marine carrion is likely to be underestimated, as it can be consumed rapidly by highly mobile scavengers (e.g. foxes, coyotes, raptors, vultures). These consumers become important vectors in transferring marine productivity inland, thereby linking marine and terrestrial ecosystems. Whilst deposits of organic matter on sandy-beach ecosystems underpin a range of ecosystem functions and services, they can be at variance with aesthetic perceptions resulting in widespread activities, such as 'beach cleaning and grooming'. This practice diminishes the energetic base of food webs, intertidal fauna, and biodiversity. Global declines in seagrass beds and kelp forests (linked to global warming) are predicted to cause substantial reductions in the amounts of marine organic matter reaching many beach ecosystems, likely causing flow-on effects for food webs and biodiversity. Similarly, future sea-level rise and increased storm frequency are likely to alter profoundly the physical attributes of beaches, which in turn can change the rates at which beaches retain and process the influxes of wrack and animal carcasses. Conservation of the multi-faceted ecosystem services that sandy beaches provide will increasingly need to encompass a greater societal appreciation and the safeguarding of ecological functions reliant on beach-cast organic matter on innumerable ocean shores worldwide.
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| 2. |
- Garratt, Michael P D, et al.
(författare)
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Opportunities to reduce pollination deficits and address production shortfalls in an important insect pollinated crop
- 2021
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Ingår i: Ecological Applications. - : Wiley. - 1051-0761 .- 1939-5582.
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Tidskriftsartikel (refereegranskat)abstract
- Pollinators face multiple pressures and there is evidence of populations in decline. As demand for insect-pollinated crops increases, crop production is threatened by shortfalls in pollination services. Understanding the extent of current yield deficits due to pollination and identifying opportunities to protect or improve crop yield and quality through pollination management is therefore of international importance. To explore the extent of 'pollination deficits', where maximum yield is not being achieved due to insufficient pollination, we use an extensive dataset on a globally important crop, apples. We quantified how these deficits vary between orchards and countries as well as compare 'pollinator dependence' across different apple varieties. We found evidence of pollination deficits and in some cases, risks of over-pollination were even apparent where fruit quality could be reduced by too much pollination. In almost all regions studied we found some orchards performing significantly better than others, in terms of avoiding a pollination deficit and crop yield shortfalls due to sub-optimal pollination. This represents an opportunity to improve production through better pollinator and crop management. Our findings also demonstrate that pollinator dependence varies considerably between apple varieties in terms of fruit number and fruit quality. We propose that assessments of pollination service and deficits in crops can be used to quantify supply and demand for pollinators and help target local management to address deficits although crop variety has a strong influence on the role of pollinators.
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| 3. |
- Hambäck, Peter A., et al.
(författare)
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Tradeoffs and synergies in wetland multifunctionality : A scaling issue
- 2023
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Ingår i: Science of the Total Environment. - Amsterdam : Elsevier BV. - 0048-9697 .- 1879-1026. ; 862
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Forskningsöversikt (refereegranskat)abstract
- Wetland area in agricultural landscapes has been heavily reduced to gain land for crop production, but in recent years there is increased societal recognition of the negative consequences from wetland loss on nutrient retention, biodiversity and a range of other benefits to humans. The current trend is therefore to re-establish wetlands, often with an aim to achieve the simultaneous delivery of multiple ecosystem services, i.e., multifunctionality. Here we review the literature on key objectives used to motivate wetland re-establishment in temperate agricultural landscapes (provision of flow regulation, nutrient retention, climate mitigation, biodiversity conservation and cultural ecosystem services), and their relationships to environmental properties, in order to identify potential for tradeoffs and synergies concerning the development of multifunctional wetlands. Through this process, we find that there is a need for a change in scale from a focus on single wetlands to wetlandscapes (multiple neighboring wetlands including their catchments and surrounding landscape features) if multiple societal and environmental goals are to be achieved. Finally, we discuss the key factors to be considered when planning for re-establishment of wetlands that can support achievement of a wide range of objectives at the landscape scale.
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| 4. |
- Hutchinson, Louise A., et al.
(författare)
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Using ecological and field survey data to establish a national list of the wild bee pollinators of crops
- 2021
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Ingår i: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 315
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Tidskriftsartikel (refereegranskat)abstract
- The importance of wild bees for crop pollination is well established, but less is known about which species contribute to service delivery to inform agricultural management, monitoring and conservation. Using sites in Great Britain as a case study, we use a novel qualitative approach combining ecological information and field survey data to establish a national list of crop pollinating bees for four economically important crops (apple, field bean, oilseed rape and strawberry). A traits data base was used to establish potential pollinators, and combined with field data to identify both dominant crop flower visiting bee species and other species that could be important crop pollinators, but which are not presently sampled in large numbers on crops flowers. Whilst we found evidence that a small number of common, generalist species make a disproportionate contribution to flower visits, many more species were identified as potential pollinators, including rare and specialist species. Furthermore, we found evidence of substantial variation in the bee communities of different crops. Establishing a national list of crop pollinators is important for practitioners and policy makers, allowing targeted management approaches for improved ecosystem services, conservation and species monitoring. Data can be used to make recommendations about how pollinator diversity could be promoted in agricultural landscapes. Our results suggest agri-environment schemes need to support a higher diversity of species than at present, notably of solitary bees. Management would also benefit from targeting specific species to enhance crop pollination services to particular crops. Whilst our study is focused upon Great Britain, our methodology can easily be applied to other countries, crops and groups of pollinating insects.
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| 5. |
- Strand, John A., et al.
(författare)
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Anlagda våtmarker som flödesbuffrare : Hur skapar vi synergieffekter medbiologisk mångfald och pollinering?
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Anlagda våtmarker har använts som naturbaserade lösningar på miljöproblem sedan 1990-talet i Sverige, framför allt i jordbrukslandskapet. Inledningsvis var huvudsyftet kostnadseffektiva åtgärder för att minska övergödningseffekter i havet men även våtmarkers positiva effekt på den biologiska mångfalden betonades tidigt. Under det senaste decenniet har anlagda våtmarker också diskuterats som lösning på andra miljönyttor, som flödesbuffring, vattenmagasinering och för att hålla kvar kol i organogena marker. För de senare ekosystemtjänsterna är forskningsläget emellertid osäkert och för vissa, såsom flödesbuffring, har det saknats faktiska mätdata. Denna brist är speciellt tydligt på de större landskapsskalor som behöver studeras för att exempelvis förstå våtmarkers och våtmarkslandskapens förmåga att förhindra översvämning lokalt och av nedströms belägna områden. I frånvaro av mätdata har förväntade positiva effekter i stället modellerats fram genom att utgå från parametrar som nederbörd och avrinningsområdens egenskaper. För att studera betydelsen av anlagda våtmarker i jordbrukslandskapet på flödesbuffring, dvs vattenmagasineringsförmågan, samt hur denna förmåga påverkar biologisk mångfald, har projektet samlat ett konsortium av experter och forskare inom framför allt ekologi och hydrologi. Inom ramen för projektet har en omfattande och strategisk provtagning genomförts under 3 år, av hydrologiska och ekologiska parametrar samt biologisk mångfald. Förutom dessa fältmätningar har även markägarnas åsikter kring värdet av sina anlagda våtmarker undersökts. Resultaten visar att anlagda våtmarker i jordbrukslandskapet har en stor potential att fungera som flödesutjämnare och buffra vatten både i den enskilda våtmarken och på landskapsnivå. Samtidigt gynnas en stor mängd organismgrupper, inklusive specialiserade våtmarksarter på nationella hotlistor. Resultaten visar också att för både flödesbuffring och biologisk mångfald finns flera avgörande parametrar vad gäller placering och design som styr hur väl en våtmark faktiskt levererar dessa ekosystemtjänster. De anlagda våtmarkerna i studien är huvudsakligen grävda dammar optimerade för näringsavskiljning och var därigenom relativt små och tog huvudsakligen emot dräneringsvatten från åkermark. Trots storleken bidrog de undersökta våtmarkerna till att dämpa högflöden med 3–17 %, vilket är i paritet med mätningar från naturliga våtmarker i tidigare studier (cirka 10 %). Det visade sig också att våtmarkerna bibehöll sina buffrande funktioner både under kortare högflödesperioder samt under ett år med hög årsnederbörd, vilket indikerar att de kan fungera med liknande effektivitet i ett framtida klimat med högre avrinning. Vid extremnederbörd framstår dock de buffrade volymerna i dessa små våtmarker som otillräckliga för att kunna fungera som (enskild) åtgärd, både idag och i framtiden. Till skillnad från naturliga våtmarker fanns inga starka samband mellan flödesbuffringen i studiens anlagda våtmarker och deras position i avrinningsområdet. Varken våtmarkens höjd över havet eller nerströms/uppströms placering i avrinningsområdet påverkade buffringsförmågan. Det fanns dock andra faktorer som påverkade våtmarkernas buffring, som att buffringen ökade med storleken på våtmarkens tillrinningsområden. Den effekten var delvis oväntad eftersom våtmarker med stora tillrinningsområde borde fyllas snabbare, vara fulla under längre tid och därmed buffra mindre effektivt. Resultaten tyder dock på att den tekniska utformningen på våtmarkerna ger dem god buffringskapacitet trots hög hydrologisk belastning. Resultaten visar också att det finns marginal för att förbättra buffringen genom tekniska anläggningsmekanismer, särskilt i fråga om tömningsmöjligheterna och reglerbarheten i utloppskonstruktionerna. Våra data visar att endast 47 % av den teoretiska volymförändringspotentialen utnyttjades i våtmarkerna, vilket kan medge ökad buffringspotential genom aktiv tömning/sänkning inför stora nederbördssituationer. De kraftiga vattennivåvariationerna i många av våtmarkerna, i kombination med förekomst av både flacka partier och brantare släntlutning, var positivt för artrikedomen hos flera organismgrupper. Generellt gynnades mångfalden hos flera grupper av större strandvåtmarker och flacka stränder, men det fanns undantag. Till exempel gynnades nätbyggande spindlar av brantare stränder. Ett oväntat resultat var också den begränsade eller till och med negativa effekten av betande djur, vilket går stick i stäv med rekommendationer i manualer för våtmarksanläggning och skötsel. Sannolikt gynnas leddjuren av att vegetationen hålls kort men samtidigt kan de rent fysiska effekterna av trampet missgynna artgrupper som har sin larvutveckling i blöt jord. För att förstå dessa samband behövs mer forskning som går in på mekanismer samt hur effekten påverkas av djurslag, djurtäthet och jordart. För insekter som utvecklas i vatten, som trollsländor, sågs inga samband med hydrologiska parametrar, men det var uppenbart att små, anlagda våtmarker är veritabla artöar för trollsländor. Totalt noterades 68 % av alla Sveriges arter på en yta (800 km2) som motsvarar 0,0015 % av Sveriges yta. Artsammansättning skilde sig mellan våtmarker och för att nå höga artantal på landskapsnivå kan det därför vara en fördel med många olika våtmarker i en region. För pollinatörer, särskilt bin, fanns korrelation mellan förekomst och storleken på våtmarkernas minsta vattenareal (dvs, när de är som mest uttorkade). Markägarenkäten visade att markägarna överlag ser mest nyttor, snarare än problem, med anlagda våtmarker. Mest notabelt var den höga nöjdheten med våtmarker (91 %) samt att en mycket stor andel markägare (83 %) använder sin våtmark för personlig rekreation, där skridskoåkning var populärast. Slutsatsen från studierna är att anlagda våtmarker som konstruerats för näringsavskiljning och i viss mån biologisk mångfald kan fungera bra som flödesbuffrare. Dessutom finns stor potential för ökad buffringskapacitet genom att både utformning (inte minst in- och utloppslösningar och aktiv nivåstyrning i våtmarkerna), läge och skötsel har en stor påverkan på den totala effekten. Dessutom verkar det finnas möjliga synergieffekter mellan vattennivåvariationer och artrikedomen av leddjur, men för att nå en hög biologisk mångfald i anlagda våtmarker bör stränderna vara heterogena eller att olika våtmarker har olika struktur.
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| 6. |
- Strandmark, Alma, et al.
(författare)
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Direct and indirect effects of island size and wave exposure on shoreline arthropod diversity
- 2020
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 47:4, s. 968-977
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Tidskriftsartikel (refereegranskat)abstract
- Aim Available theories suggest that the species number increases with island size, but the relationship between island size and species density, the number of species per unit area, is less understood. Moreover, mechanisms connecting island size and species density are not always evident because small and large islands differ in physical characteristics other than island size. The purpose here was to disentangle direct and indirect effects of island size and wave exposure on the species density of arthropods from herb-dominated shore habitats. Location Islands in the Stockholm Archipelago, Sweden. Taxon Spiders (Araneae) and beetles (Coleoptera). Methods We collected spiders and beetles on vegetated shores on islands of varying sizes, and used structural equation models to disentangle direct and indirect island size and wave exposure effects on species density. Results Island size affected diversity of web-building spiders, predatory beetles and other beetles (detritivores and omnivores), direct and indirectly. Indirect effects arose because large islands have more trees and steeper slopes than small islands, both of which affected species occurrence. Because height above the sea level reduces the effect of wave exposure, there were effects of these variables on the forest cover and on the diversity of web-building spiders. Finally, surrounding forest cover and diversity of flowering plants within sites increased diversity of herbivore beetles and cursorial spiders, likely because these sites provide more diverse resources. Main conclusions The result that predictors for species density vary between functional groups, with mechanisms that may or may not relate to island size, suggest potential developments in island biogeography theories. Future studies of island size effects should also attempt to quantify indirect effects, and not only total effects.
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| 7. |
- Aguirrebengoa, Martin, et al.
(författare)
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Density-Dependent Effects of Simultaneous Root and Floral Herbivory on Plant Fitness and Defense
- 2023
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Ingår i: PLANTS. - : MDPI AG. - 2223-7747. ; 12:2
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Tidskriftsartikel (refereegranskat)abstract
- Plants are attacked by multiple herbivores, and depend on a precise regulation of responses to cope with a wide range of antagonists. Simultaneous herbivory can occur in different plant compartments, which may pose a serious threat to plant growth and reproduction. In particular, plants often face co-occurring root and floral herbivory, but few studies have focused on such interactions. Here, we investigated in the field the combined density-dependent effects of root-chewing cebrionid beetle larvae and flower-chewing pierid caterpillars on the fitness and defense of a semiarid Brassicaceae herb. We found that the fitness impact of both herbivore groups was independent and density-dependent. Increasing root herbivore density non-significantly reduced plant fitness, while the relationship between increasing floral herbivore density and the reduction they caused in both seed number and seedling emergence was non-linear. The plant defensive response was non-additive with regard to the different densities of root and floral herbivores; high floral herbivore density provoked compensatory investment in reproduction, and this tolerance response was combined with aboveground chemical defense induction when also root herbivore density was high. Plants may thus prioritize specific trait combinations in response to varying combined below- and aboveground herbivore densities to minimize negative impacts on fitness.
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| 8. |
- An, Yueqing, 1994-, et al.
(författare)
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Host Phylogeny Structures the Gut Bacterial Community Within Galerucella Leaf Beetles
- 2023
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Ingår i: Microbial Ecology. - 0095-3628 .- 1432-184X. ; 86:4, s. 2477-2487
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Tidskriftsartikel (refereegranskat)abstract
- Gut microbes play important roles for their hosts. Previous studies suggest that host-microbial systems can form long-term associations over evolutionary time and the dynamic changes of the intestinal system may represent major driving forces and contribute to insect dietary diversification and speciation. Our study system includes a set of six closely related leaf beetle species (Galerucella spp.) and our study aims to separate the roles of host phylogeny and ecology in determining the gut microbial community and to identify eventual relationship between host insects and gut bacteria. We collected adult beetles from their respective host plants and quantified their microbial community using 16S rRNA sequencing. The results showed that the gut bacteria community composition was structured by host beetle phylogeny, where more or less host-specific gut bacteria interact with the different Galerucella species. For example, the endosymbiotic bacteria Wolbachia was found almost exclusively in G. nymphaea and G. sagittariae. Diversity indicators also suggested that α- and β-diversities of gut bacteria communities varied among host beetle species. Overall, our results suggest a phylogenetically controlled co-occurrence pattern between the six closely related Galerucella beetles and their gut bacteria, indicating the potential of co-evolutionary processes occurring between hosts and their gut bacterial communities.
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| 9. |
- Cuff, Jordan P., et al.
(författare)
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Sources of prey availability data alter interpretation of outputs from prey choice null networks
- 2024
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Ingår i: Ecological Entomology. - 0307-6946 .- 1365-2311.
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Tidskriftsartikel (refereegranskat)abstract
- Null models provide a valuable baseline against which fundamental ecological hypotheses can be tested and foraging choices that cannot be explained by neutral processes or sampling biases can be highlighted. In this way, null models can advance our understanding beyond simplistic dietary descriptions to identify drivers of interactions. This method, however, requires estimates of resource availability, which are generally imperfect representations of highly dynamic systems. Optimising method selection is crucial for study design, but the precise effects of different resource availability data on the efficacy of null models are poorly understood.Using spider–prey networks as a model, we used prey abundance (suction sample) and activity density (sticky trap) data, and combinations of the two, to simulate null networks. We compared null diet composition, network properties (e.g., connectance and nestedness) and deviations of simulations from metabarcoding-based spider dietary data to ascertain how different prey availability data alter ecological interpretation.Different sampling methods produced different null networks and inferred distinct prey selectivity. Null models based on prey abundance and combined frequency-of-occurrence data generated null diet compositions, which more closely resembled the diet composition determined by metabarcoding. Null models based on prey abundance, activity density and proportionally combined data generated null network properties most like the networks constructed via dietary metabarcoding.We show that survey method choice impacts all aspects of null network analyses, the precise effects varying between methods but ultimately altering ecological interpretation by increasing disparity in network properties or trophic niches between null and directly constructed networks. Merging datasets can generate more complete prey availability data but is not a panacea because it introduces different biases. The choice of method should reflect the research hypotheses and study system being investigated. Ultimately, survey methods should emulate the foraging mode of the focal predator as closely as possible, informed by the known ecology, natural history and behaviour of the predator.
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| 10. |
- Faticov, Maria, 1991-, et al.
(författare)
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Different spatial structure of plant-associated fungal communities above- and belowground
- 2023
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Ingår i: Ecology and Evolution. - 2045-7758. ; 13:5
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Tidskriftsartikel (refereegranskat)abstract
- The distribution and community assembly of above- and belowground microbial communities associated with individual plants remain poorly understood, despite its consequences for plant–microbe interactions and plant health. Depending on how microbial communities are structured, we can expect different effects of the microbial community on the health of individual plants and on ecosystem processes. Importantly, the relative role of different factors will likely differ with the scale examined. Here, we address the driving factors at a landscape level, where each individual unit (oak trees) is accessible to a joint species pool. This allowed to quantify the relative effect of environmental factors and dispersal on the distribution of two types of fungal communities: those associated with the leaves and those associated with the soil of Quercus robur trees in a landscape in southwestern Finland. Within each community type, we compared the role of microclimatic, phenological, and spatial variables, and across community types, we examined the degree of association between the respective communities. Most of the variation in the foliar fungal community was found within trees, whereas soil fungal community composition showed positive spatial autocorrelation up to 50 m. Microclimate, tree phenology, and tree spatial connectivity explained little variation in the foliar and soil fungal communities. Foliar and soil fungal communities differed strongly in community structure, with no significant concordance detected between them. We provide evidence that foliar and soil fungal communities assemble independent of each other and are structured by different ecological processes.
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