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David H Wise - One of the best experts on this subject based on the ideXlab platform.
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plant invader alters soil food web via changes to fungal resources
Oecologia, 2019Co-Authors: Matthew A Mccary, David H WiseAbstract:: While aboveground impacts of invasive plants are well documented, their influence on soil food webs remains less understood. Previous research has revealed that bottom-up forces are widespread in soil food webs of woodlands. Thus, an invasive plant that negatively impacts the base of the food web will likely decrease primary consumers as well as their predators. We examined how a North American plant invader, garlic mustard (Alliaria petiolata), affects arthropod primary (springtails and oribatid mites) and secondary (predaceous mites) consumers of the soil food web via changes to fungal resources. We measured the abundances of plants, soil fungi, Fungivores, and predators in garlic mustard-invaded and uninvaded 1-m2 plots in five Midwestern USA woodlands. We then conducted a mesocosm (0.25-m2 plots) experiment to tease apart the direct and indirect effects of garlic mustard by manipulating plant identity (garlic mustard vs. native plant), soil history (invaded vs. uninvaded), and fungicide application (fungicide vs. no fungicide). Our first study revealed that plots without garlic mustard had 2.8 and 1.4 × more fungi and Fungivores, respectively. Predator densities did not differ. Fungal composition and structural equation modeling (SEM) revealed the garlic mustard effects on Fungivores were correlated with fungal declines. The mesocosm experiment confirmed that the impacts were indirect, as fungicide plots harbored similar fungivore densities, whereas fungivore densities differed according to plant identity and soil history in the fungicide-free plots. Our results reveal that by altering soil fungal abundance, an invasive plant can indirectly affect primary consumers in soil food webs, but this indirect effect does not influence predators.
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invasive plants have different effects on trophic structure of green and brown food webs in terrestrial ecosystems a meta analysis
Ecology Letters, 2016Co-Authors: Matthew A Mccary, Robin Mores, Monica A. Farfan, David H WiseAbstract:Although invasive plants are a major source of terrestrial ecosystem degradation worldwide, it remains unclear which trophic levels above the base of the food web are most vulnerable to plant invasions. We performed a meta-analysis of 38 independent studies from 32 papers to examine how invasive plants alter major groupings of primary and secondary consumers in three globally distributed ecosystems: wetlands, woodlands and grasslands. Within each ecosystem we examined if green (grazing) food webs are more sensitive to plant invasions compared to brown (detrital) food webs. Invasive plants have strong negative effects on primary consumers (detritivores, bacterivores, Fungivores, and/or herbivores) in woodlands and wetlands, which become less abundant in both green and brown food webs in woodlands and green webs in wetlands. Plant invasions increased abundances of secondary consumers (predators and/or parasitoids) only in woodland brown food webs and green webs in wetlands. Effects of invasive plants on grazing and detrital food webs clearly differed between ecosystems. Overall, invasive plants had the most pronounced effects on the trophic structure of wetlands and woodlands, but caused no detectable changes to grassland trophic structure.
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invasive plants have different effects on trophic structure of green and brown food webs in terrestrial ecosystems a meta analysis
Ecology Letters, 2016Co-Authors: Matthew A Mccary, Robin Mores, Monica A. Farfan, David H WiseAbstract:Although invasive plants are a major source of terrestrial ecosystem degradation worldwide, it remains unclear which trophic levels above the base of the food web are most vulnerable to plant invasions. We performed a meta-analysis of 38 independent studies from 32 papers to examine how invasive plants alter major groupings of primary and secondary consumers in three globally distributed ecosystems: wetlands, woodlands and grasslands. Within each ecosystem we examined if green (grazing) food webs are more sensitive to plant invasions compared to brown (detrital) food webs. Invasive plants have strong negative effects on primary consumers (detritivores, bacterivores, Fungivores, and/or herbivores) in woodlands and wetlands, which become less abundant in both green and brown food webs in woodlands and green webs in wetlands. Plant invasions increased abundances of secondary consumers (predators and/or parasitoids) only in woodland brown food webs and green webs in wetlands. Effects of invasive plants on grazing and detrital food webs clearly differed between ecosystems. Overall, invasive plants had the most pronounced effects on the trophic structure of wetlands and woodlands, but caused no detectable changes to grassland trophic structure.
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bottom up limitation of predaceous arthropods in a detritus based terrestrial food web
Ecology, 1999Co-Authors: Benrong Chen, David H WiseAbstract:Knowing how an increase in the resource base of a food web produces effects that propagate through the web is central to developing a clearer understanding of food- web structure and dynamics. In a detritus-based terrestrial food web, we measured the responses of predaceous arthropods to increases in prey arthropods that occurred in response to experimentally enhancing the web's resource base. Open 2 X 5 m plots on the floor of a deciduous forest were randomly assigned to either a Food Enhancement or Control treat- ment. We supplemented the resource base of the arthropod community of the leaf litter layer for 3.5 mo by periodically adding chopped mushrooms, potatoes, and instant fruit fly medium to the Food Enhancement plots. Major taxa of detritivores and Fungivores increased in response to added food. Densities of springtails (Collembola) were on average 3 X higher in the Food Enhancement than Control plots. Numbers of adult fungus gnats (Diptera: Sciaridae and Mycetophilidae) did not differ significantly between treatments after 6 wk but were >2X higher in Food Enhancement plots at the end of the experiment. Total Diptera were twice as abundant in Food Enhancement plots on both census dates. Arthropod groups that include a range of feeding strategies also increased. Mites (Ac- arina), which include detritivores, Fungivores, and predators, were twice as abundant in the experimental treatment. Staphylinid and carabid beetles (Coleoptera), which are primarily predaceous but include omnivorous species, were several times more numerous in the Food Enhancement plots. Effects of increasing the resource base propagated through the food web, leading to higher densities of the major strictly predaceous arthropod taxa. Centipedes (Chilopoda), pseudoscorpions (Pseudoscorpionida), and spiders (Araneae) were -2X as abundant in the Food Enhancement treatment. Thus, our experiment uncovered substantial bottom-up lim- itation in this detritus-based food web, expressed as responses by predaceous arthropods at least two trophic links removed from the experimentally elevated resource.
Matthew A Mccary - One of the best experts on this subject based on the ideXlab platform.
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plant invader alters soil food web via changes to fungal resources
Oecologia, 2019Co-Authors: Matthew A Mccary, David H WiseAbstract:: While aboveground impacts of invasive plants are well documented, their influence on soil food webs remains less understood. Previous research has revealed that bottom-up forces are widespread in soil food webs of woodlands. Thus, an invasive plant that negatively impacts the base of the food web will likely decrease primary consumers as well as their predators. We examined how a North American plant invader, garlic mustard (Alliaria petiolata), affects arthropod primary (springtails and oribatid mites) and secondary (predaceous mites) consumers of the soil food web via changes to fungal resources. We measured the abundances of plants, soil fungi, Fungivores, and predators in garlic mustard-invaded and uninvaded 1-m2 plots in five Midwestern USA woodlands. We then conducted a mesocosm (0.25-m2 plots) experiment to tease apart the direct and indirect effects of garlic mustard by manipulating plant identity (garlic mustard vs. native plant), soil history (invaded vs. uninvaded), and fungicide application (fungicide vs. no fungicide). Our first study revealed that plots without garlic mustard had 2.8 and 1.4 × more fungi and Fungivores, respectively. Predator densities did not differ. Fungal composition and structural equation modeling (SEM) revealed the garlic mustard effects on Fungivores were correlated with fungal declines. The mesocosm experiment confirmed that the impacts were indirect, as fungicide plots harbored similar fungivore densities, whereas fungivore densities differed according to plant identity and soil history in the fungicide-free plots. Our results reveal that by altering soil fungal abundance, an invasive plant can indirectly affect primary consumers in soil food webs, but this indirect effect does not influence predators.
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invasive plants have different effects on trophic structure of green and brown food webs in terrestrial ecosystems a meta analysis
Ecology Letters, 2016Co-Authors: Matthew A Mccary, Robin Mores, Monica A. Farfan, David H WiseAbstract:Although invasive plants are a major source of terrestrial ecosystem degradation worldwide, it remains unclear which trophic levels above the base of the food web are most vulnerable to plant invasions. We performed a meta-analysis of 38 independent studies from 32 papers to examine how invasive plants alter major groupings of primary and secondary consumers in three globally distributed ecosystems: wetlands, woodlands and grasslands. Within each ecosystem we examined if green (grazing) food webs are more sensitive to plant invasions compared to brown (detrital) food webs. Invasive plants have strong negative effects on primary consumers (detritivores, bacterivores, Fungivores, and/or herbivores) in woodlands and wetlands, which become less abundant in both green and brown food webs in woodlands and green webs in wetlands. Plant invasions increased abundances of secondary consumers (predators and/or parasitoids) only in woodland brown food webs and green webs in wetlands. Effects of invasive plants on grazing and detrital food webs clearly differed between ecosystems. Overall, invasive plants had the most pronounced effects on the trophic structure of wetlands and woodlands, but caused no detectable changes to grassland trophic structure.
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invasive plants have different effects on trophic structure of green and brown food webs in terrestrial ecosystems a meta analysis
Ecology Letters, 2016Co-Authors: Matthew A Mccary, Robin Mores, Monica A. Farfan, David H WiseAbstract:Although invasive plants are a major source of terrestrial ecosystem degradation worldwide, it remains unclear which trophic levels above the base of the food web are most vulnerable to plant invasions. We performed a meta-analysis of 38 independent studies from 32 papers to examine how invasive plants alter major groupings of primary and secondary consumers in three globally distributed ecosystems: wetlands, woodlands and grasslands. Within each ecosystem we examined if green (grazing) food webs are more sensitive to plant invasions compared to brown (detrital) food webs. Invasive plants have strong negative effects on primary consumers (detritivores, bacterivores, Fungivores, and/or herbivores) in woodlands and wetlands, which become less abundant in both green and brown food webs in woodlands and green webs in wetlands. Plant invasions increased abundances of secondary consumers (predators and/or parasitoids) only in woodland brown food webs and green webs in wetlands. Effects of invasive plants on grazing and detrital food webs clearly differed between ecosystems. Overall, invasive plants had the most pronounced effects on the trophic structure of wetlands and woodlands, but caused no detectable changes to grassland trophic structure.
Wenju Liang - One of the best experts on this subject based on the ideXlab platform.
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soil microbial food web channels associated with biological soil crusts in desertification restoration the carbon flow from microbes to nematodes
Soil Biology & Biochemistry, 2018Co-Authors: Pingting Guan, Yunyun Cheng, Walter S Andriuzzi, Xiaoke Zhang, Jun Yu, Wenju LiangAbstract:Abstract Development from bare soil to biological soil crust (BSC) after the establishment of vegetation for sand fixation is an important desertification rehabilitation process in dryland ecosystems. While subsequent changes aboveground have been well documented, few studies focused on how BSC affects soil food webs after vegetation establishment. In this study, we investigated how soil food web channels respond to BSC, and in particular how flow of carbon from microbes to higher trophic levels is affected in Horqin Sandy Land, China. The BSC layer and 0–1 cm depth soil layer without BSC (as the control of BSC) were taken. After that, soil samples of 10 cm depth were collected and then dividing into two equal 5 cm parts for comparing soil microbe and nematode community composition in 2013 and 2014. The results showed that presence of BSC increased the phospholipid fatty acid and biomass carbon of microbes in the top layer of both years. Abundance, biomass carbon, and metabolic footprint of nematode trophic groups, including Fungivores and omnivores-predators in the top layer, had higher values under BSC. Positive relationships were found between total organic carbon of BSC and biomass carbon of fungi, and between biomass carbon of fungi and Fungivores. BSC enhanced carbon flow from fungi to Fungivores, with higher connectance values in the fungal channel than in soil without BSC. The strengthened relationships between total organic carbon of BSC and omnivore-predator, and high connectances of the fungal channel and of the omnivore-predator channel under BSC, suggest a more reticulated channel in soil food web. It can be concluded that colonization of BSC enhances the connenctances in soil microbial food web channels, and could contribute to the resilience of dryland ecosystems.
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tillage and rotation effects on community composition and metabolic footprints of soil nematodes in a black soil
European Journal of Soil Biology, 2015Co-Authors: Zhiyong Zhang, Xiaoke Zhang, Jiasiang Jhao, Xiaoping Zhang, Wenju LiangAbstract:Abstract Understanding the response of soil biota to tillage and rotation practices is useful for evaluating the effect of agricultural management. We investigated soil physiochemical properties, nematode community structure and composition and their metabolic footprints in different tillage and crop rotation systems in a 12-year old field experiment in a black soil. The experiment was based on a split-plot design with conventional tillage (CT) and no-tillage (NT) as main plots and corn-soybean rotation (CS) and continuous corn (CC) treatments as subplots. Soil samples were taken at 0–5 cm and 5–15 cm depths. The results showed that in comparison with CT, NT increased total soil organic carbon, soil moisture and microbial biomass carbon at 0–5 cm depth regardless of rotation system. Rotation effect on total nematode abundance was significant. The abundance of Fungivores was significantly influenced by the tillage effect, with higher abundance found in CT systems. In total, fifty-eight nematode genera were identified. Acrobeloides dominated under CS and Filenchus under CC. In NT system, a bacterial-dominated decomposition pathway was dominant under CS, and fungal-based channel under CC at 0–5 cm depth. The interactive effect of tillage and rotation changed the decomposition channel. Under CS system, lower structure index (SI) and higher channel index (CI) were found in CT than in NT at 0–5 cm depth. At both depths, functional metabolic footprint was greater under CS than under CC in both tillage systems. Footprint of Fungivores also suggested a greater flow of resources into the food web through fungivorous channels under CC. Redundancy analysis (RDA) showed that tillage and rotation influenced soil nematodes by changing soil physiochemical properties. Nematode community analysis indicated that corn-soybean rotation system increased nematode abundance and their functional metabolic footprint, and favored a more diverse residue resource entry into soil food webs.
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The abundances of total nematodes and trophic groups among different water or/and N addition treatments.
2013Co-Authors: Xiaoming Sun, Xiaoke Zhang, Shixiu Zhang, Guanhua Dai, Shijie Han, Wenju LiangAbstract:Bars indicate standard errors. OP, omnivores-predators; PP, plant-parasites; FF, Fungivores; BF, bacterivores.
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Structural equation models of water addition and N addition effects on soil nematode communities
2013Co-Authors: Xiaoming Sun, Xiaoke Zhang, Shixiu Zhang, Guanhua Dai, Shijie Han, Wenju LiangAbstract:(χ2 = 41.08; df = 30; P = 0.09; GFI = 0.79; CFI = 0.96; RMSEA = 0.13). Numbers on arrows are standardized path coefficients. Width of the arrows indicates the strength of the causal influence. Dashed and straight lines represent significant and non-significant pathways, respectively. Nitrogen, N addition effect; Water, water addition effect; Nema, soil nematode communities; Soil, soil properties; SOC, total soil organic carbon; TN, total nitrogen; SM, soil moisture; TEM, total nematodes; FF, the abundance of Fungivores; PP, the abundance of plant-parasites; and OP, the abundance of omnivores-predators.
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nitrogen addition regulates soil nematode community composition through ammonium suppression
PLOS ONE, 2012Co-Authors: Cunzheng Wei, Wenju Liang, Huifen Zheng, Haiyang Zhang, Quansheng Chen, Paul Kardol, Xingguo HanAbstract:Nitrogen (N) enrichment resulting from anthropogenic activities has greatly changed the composition and functioning of soil communities. Nematodes are one of the most abundant and diverse groups of soil organisms, and they occupy key trophic positions in the soil detritus food web. Nematodes have therefore been proposed as useful indicators for shifts in soil ecosystem functioning under N enrichment. Here, we monitored temporal dynamics of the soil nematode community using a multi-level N addition experiment in an Inner Mongolia grassland. Measurements were made three years after the start of the experiment. We used structural equation modeling (SEM) to explore the mechanisms regulating nematode responses to N enrichment. Across the N enrichment gradient, significant reductions in total nematode abundance, diversity (H' and taxonomic richness), maturity index (MI), and the abundance of root herbivores, Fungivores and omnivores-predators were found in August. Root herbivores recovered in September, contributing to the temporal variation of total nematode abundance across the N gradient. Bacterivores showed a hump-shaped relationship with N addition rate, both in August and September. Ammonium concentration was negatively correlated with the abundance of total and herbivorous nematodes in August, but not in September. Ammonium suppression explained 61% of the variation in nematode richness and 43% of the variation in nematode trophic group composition. Ammonium toxicity may occur when herbivorous nematodes feed on root fluid, providing a possible explanation for the negative relationship between herbivorous nematodes and ammonium concentration in August. We found a significantly positive relationship between Fungivores and fungal phospholipid fatty acids (PLFA), suggesting bottom-up control of Fungivores. No such relationship was found between bacterivorous nematodes and bacterial PLFA. Our findings contribute to the understanding of effects of N enrichment in semiarid grassland on soil nematode trophic groups, and the cascading effects in the detrital soil food web.
Marie Duhamel - One of the best experts on this subject based on the ideXlab platform.
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do Fungivores trigger the transfer of protective metabolites from host plants to arbuscular mycorrhizal hyphae
Ecology, 2013Co-Authors: Marie Duhamel, Astra Ooms, Heike Bucking, Tjalf Wouda, Jacintha Ellers, Philippe Vandenkoornhuyse, Nico M. Van Straalen, Jan Janša, Toby E KiersAbstract:A key objective in ecology is to understand how cooperative strategies evolve and are maintained in species networks. Here, we focus on the tri-trophic relationship between arbuscular mycorrhizal (AM) fungi, host plants, and Fungivores to ask if host plants are able to protect their mutualistic mycorrhizal partners from being grazed. Specifically, we test whether secondary metabolites are transferred from hosts to fungal partners to increase their defense against Fungivores. We grew Plantago lanceolata hosts with and without mycorrhizal inoculum, and in the presence or absence of fungivorous springtails. We then measured fungivore effects on host biomass and mycorrhizal abundance (using quantitative PCR) in roots and soil. We used high-performance liquid chromatography to measure host metabolites in roots, shoots, and hyphae, focusing on catalpol, aucubin, and verbascoside. Our most striking result was that the metabolite catalpol was consistently found in AM fungal hyphae in host plants exposed to Fungivores. When Fungivores were absent, catalpol was undetectable in hyphae. Our results highlight the potential for plant-mediated protection of the mycorrhizal hyphal network.
Toby E Kiers - One of the best experts on this subject based on the ideXlab platform.
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do Fungivores trigger the transfer of protective metabolites from host plants to arbuscular mycorrhizal hyphae
Ecology, 2013Co-Authors: Marie Duhamel, Astra Ooms, Heike Bucking, Tjalf Wouda, Jacintha Ellers, Philippe Vandenkoornhuyse, Nico M. Van Straalen, Jan Janša, Toby E KiersAbstract:A key objective in ecology is to understand how cooperative strategies evolve and are maintained in species networks. Here, we focus on the tri-trophic relationship between arbuscular mycorrhizal (AM) fungi, host plants, and Fungivores to ask if host plants are able to protect their mutualistic mycorrhizal partners from being grazed. Specifically, we test whether secondary metabolites are transferred from hosts to fungal partners to increase their defense against Fungivores. We grew Plantago lanceolata hosts with and without mycorrhizal inoculum, and in the presence or absence of fungivorous springtails. We then measured fungivore effects on host biomass and mycorrhizal abundance (using quantitative PCR) in roots and soil. We used high-performance liquid chromatography to measure host metabolites in roots, shoots, and hyphae, focusing on catalpol, aucubin, and verbascoside. Our most striking result was that the metabolite catalpol was consistently found in AM fungal hyphae in host plants exposed to Fungivores. When Fungivores were absent, catalpol was undetectable in hyphae. Our results highlight the potential for plant-mediated protection of the mycorrhizal hyphal network.
