Nitrogen enrichment modifies plant community structure via changes to plant–soil feedback

Manning, Peter; Morrison, Scott; Bonkowski, Michael; Bardgett, Richard D.

doi:10.1007/s00442-008-1104-0

Cited by 98 publications

(92 citation statements)

References 48 publications

(58 reference statements)

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“…The microbial denitrifying community may have increased in abundance or changed in composition as a result of the annual grass invasion or increased soil nitrate. The most common change detected following weed invasion is an increase in nitrifier abundance or nitrification rates (10,14,20,23,27).…”

Section: Discussionmentioning

confidence: 99%

The Abundance of Microbial Functional Genes in Grassy Woodlands Is Influenced More by Soil Nutrient Enrichment than by Recent Weed Invasion or Livestock Exclusion

Lindsay

Colloff

Gibb

et al. 2010

Appl Environ Microbiol

105

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A diverse soil microbial community is involved in nitrogen cycling, and these microbes can be affected by land management practices and weed invasion. We surveyed 20 woodlands with a history of livestock grazing, with livestock recently excluded from 10 sites. We investigated whether soil nutrients were lower when grazing was excluded and higher when exotic grasses dominated the understory. Second, using quantitative real-time PCR, we investigated whether microbial nitrogen functional gene (NFG) abundance was altered with soil nutrient enrichment, livestock exclusion, and exotic grass invasion. The target genes were chiA (decomposition-ammonification), nifH (nitrogen fixation), nirK and narG (denitrification), and bacterial amoA (nitrification). Woodland soils were enriched in phosphorus and nitrogen compared to reference condition sites, but soil nutrients were not lower following livestock exclusion. Total nitrogen and nifH were negatively correlated in grazed woodlands, suggesting that aboveground herbivory reduces the capacity for belowground nitrogen fixation. Woodlands dominated by exotic grasses had higher levels of nitrate, narG, and nirK than those dominated by native grasses. We hypothesize that the increase in potential for denitrification was due to increases in soil nitrate, rather than changes in plant composition. Overall, soil physicochemistry explained more variation in NFG abundance than livestock presence or plant invasion, particularly for chiA and bacterial amoA, with significant relationships between the abundance of all five NFGs and total nitrogen or nitrate. All woodlands investigated had a history of anthropogenic disturbance and nutrification, and soil nutrient levels and the abundance of NFGs are likely to be related to long-term land management practices.

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Section: Discussionmentioning

confidence: 99%

The Abundance of Microbial Functional Genes in Grassy Woodlands Is Influenced More by Soil Nutrient Enrichment than by Recent Weed Invasion or Livestock Exclusion

Lindsay

Colloff

Gibb

et al. 2010

Appl Environ Microbiol

105

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“…The lack of soil biotic effects on plant growth in our study presumably arose because of the overriding importance of abiotic factors (e.g. high concentrations of mineral soil nutrients) in determining growth; such abiotic factors may operate as important determinants of the occurrence and strength of plant-soil feedbacks [19].…”

Section: Discussionmentioning

confidence: 99%

Soil-mediated indirect impacts of an invasive predator on plant growth

et al. 2012

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While several studies have shown that invasive plant effects on soil biota influence subsequent plant performance, corresponding studies on how invasive animals affect plants through influencing soil biota are lacking. This is despite the fact that invasive animals often indirectly alter the below-ground subsystem. We studied 18 offshore islands in northern New Zealand, half of which have been invaded by rats that are predators of seabirds and severely reduce their densities, and half of which remain non-invaded; invasion of rats thwarts seabird transfer of resources from ocean to land. We used soil from each island in a glasshouse experiment involving soil sterilization treatments to determine whether rat invasion indirectly influences plant growth through the abiotic pathway (by impairing seabird-driven inputs to soil) or the biotic pathway (by altering the soil community). Rat invasion greatly impaired plant growth but entirely through the abiotic pathway. Plant growth was unaffected by the soil community or its response to invasion, meaning that the responses of plants and soil biota to invasion are decoupled. Our results provide experimental evidence for the powerful indirect effects that predator-instigated cascades can exert on plant and ecosystem productivity, with implications for the restoration of island ecosystems by predator removal.

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“…There is evidence that the strength and direction of plantsoil feedback depend on environmental context, particularly nutrient availability [43,44]. To address this further, controlled feedback experiments [45] using plant species and soils collected along soil chronosequences are needed to determine whether and how plant-soil feedback drives plant diversity during pedogenesis.…”

Section: Role Of Belowground Heterotrophsmentioning

confidence: 99%