Limits...
Root traits predict decomposition across a landscape-scale grazing experiment.

Smith SW, Woodin SJ, Pakeman RJ, Johnson D, van der Wal R - New Phytol. (2014)

Bottom Line: Livestock grazing increased soil temperatures, but this did not affect root decomposition.Grazing had no effect on soil moisture, but wetter soils retarded root decomposition.Our results suggest that large herbivores alter below-ground carbon and nitrogen dynamics more through their effects on plant species composition and associated root traits than through effects on the soil microclimate.

View Article: PubMed Central - PubMed

Affiliation: IBES, University of Aberdeen, St Machar Drive, Aberdeen, AB24 3UU, UK; The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK; ACES, University of Aberdeen, St Machar Drive, Aberdeen, AB24 3UU, UK.

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Soil temperature (a) and moisture (b) for spot measurements at the point where individual litterbags were buried under four species swards (Agrostis capillaris, Juncus effusus, Molinia caerulea, Nardus stricta) for the main grazing experiment. All litterbag points are shown as white symbols. Grazing treatments are indicated in the key. Mean soil temperature and moisture for each grazing treatment are shown in corresponding larger grey-filled symbols. The asterisk is the mean soil temperature and soil moisture in the common-garden experiment (M. caerulea-dominated) where litterbags of all four species were buried.
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fig01: Soil temperature (a) and moisture (b) for spot measurements at the point where individual litterbags were buried under four species swards (Agrostis capillaris, Juncus effusus, Molinia caerulea, Nardus stricta) for the main grazing experiment. All litterbag points are shown as white symbols. Grazing treatments are indicated in the key. Mean soil temperature and moisture for each grazing treatment are shown in corresponding larger grey-filled symbols. The asterisk is the mean soil temperature and soil moisture in the common-garden experiment (M. caerulea-dominated) where litterbags of all four species were buried.

Mentions: Soils were significantly warmer under more intense livestock grazing in swards of all four dominant upland grass species (Fig. 1; Table 1), with the greatest treatment differences in A. capillaris swards (1.38 ± 0.16°C (± 1 SD) warmer under commercial than under no grazing). However, differences in soil temperature did not significantly impact any measure of root decomposition (Table 1). Instead, increasing soil moisture significantly reduced mass and C loss from root litter (Fig. 2), but livestock grazing did not affect soil moisture (Fig. 1; Table 1).


Root traits predict decomposition across a landscape-scale grazing experiment.

Smith SW, Woodin SJ, Pakeman RJ, Johnson D, van der Wal R - New Phytol. (2014)

Soil temperature (a) and moisture (b) for spot measurements at the point where individual litterbags were buried under four species swards (Agrostis capillaris, Juncus effusus, Molinia caerulea, Nardus stricta) for the main grazing experiment. All litterbag points are shown as white symbols. Grazing treatments are indicated in the key. Mean soil temperature and moisture for each grazing treatment are shown in corresponding larger grey-filled symbols. The asterisk is the mean soil temperature and soil moisture in the common-garden experiment (M. caerulea-dominated) where litterbags of all four species were buried.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4260134&req=5

fig01: Soil temperature (a) and moisture (b) for spot measurements at the point where individual litterbags were buried under four species swards (Agrostis capillaris, Juncus effusus, Molinia caerulea, Nardus stricta) for the main grazing experiment. All litterbag points are shown as white symbols. Grazing treatments are indicated in the key. Mean soil temperature and moisture for each grazing treatment are shown in corresponding larger grey-filled symbols. The asterisk is the mean soil temperature and soil moisture in the common-garden experiment (M. caerulea-dominated) where litterbags of all four species were buried.
Mentions: Soils were significantly warmer under more intense livestock grazing in swards of all four dominant upland grass species (Fig. 1; Table 1), with the greatest treatment differences in A. capillaris swards (1.38 ± 0.16°C (± 1 SD) warmer under commercial than under no grazing). However, differences in soil temperature did not significantly impact any measure of root decomposition (Table 1). Instead, increasing soil moisture significantly reduced mass and C loss from root litter (Fig. 2), but livestock grazing did not affect soil moisture (Fig. 1; Table 1).

Bottom Line: Livestock grazing increased soil temperatures, but this did not affect root decomposition.Grazing had no effect on soil moisture, but wetter soils retarded root decomposition.Our results suggest that large herbivores alter below-ground carbon and nitrogen dynamics more through their effects on plant species composition and associated root traits than through effects on the soil microclimate.

View Article: PubMed Central - PubMed

Affiliation: IBES, University of Aberdeen, St Machar Drive, Aberdeen, AB24 3UU, UK; The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK; ACES, University of Aberdeen, St Machar Drive, Aberdeen, AB24 3UU, UK.

Show MeSH
Related in: MedlinePlus