Pedosphere 26(4): 567--576, 2016
ISSN 1002-0160/CN 32-1315/P
©2016 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Soil respiration and litter decomposition increased following perennial forb invasion into an annual grassland |
ZHANG Ling1,2,MA Xiao-Chi2, WANG Hong2, LIU Shu-Wei2, E. SIEMANN2,3 and ZOU Jian-Wen2 |
1College of Forestry, Jiangxi Agricultural University, Nanchang 330045 (China)
2College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China)
3Department of Ecology and Evolutionary Biology, Rice University, Houston TX 77005 (USA) |
| ABSTRACT |
| Exotic plant invasions may alter ecosystem carbon processes, especially when native plants are displaced by plants of a different functional group. Forb invasions into grasslands are common, yet little is known about how they impact carbon cycling. We conducted a field study over 2 years from April 2010 to March 2012 in China to examine changes in soil respiration (Rsoil) following invasion of exotic perennial forb species (Alternanthera philoxeroides or Solidago canadensis) into an annual grassland dominated by a native annual graminoid (Eragrostis pilosa). Measurements of Rsoil were taken once a week in stands of the native annual graminoidor one of the forb species using static chamber-gas chromatograph method. Aboveground litterfall of each of the three focal species was collected biweekly and litter decomposition rates were measured in a 6-month litterbag experiment. The monthly average and annual cumulative Rsoil increased following invasion by either forb species. The increasesin cumulative Rsoil were smaller with invasion of Solidago (36%) than Alternanthera(65%). Both invasive forbs were associated with higher litter quantity and quality (e.g., C:N ratio) than the native annual graminoid. Compared to the native annual graminoid, the invasive forbs Alternanthera (155%) and Solidago (361%) produced larger amountsof more rapidly decomposing litter, with the litter decay constant k being 3.8, 2.0 and 1.0 for Alternanthera, Solidago and Eragrostis, respectively. Functional groups of the invasive plants and the native plants they replacedappear to be useful predictors of directions of changes in Rsoil, but the magnitude of changes in Rsoilseems to be sensitive to variations in invader functional traits. |
| Key Words: carbon cycling, exotic plant,functional group, functional traits,invasive plants, litterfall, native plants |
| Citation: Zhang, L., Ma, X. C., Wang, H., Liu, S. W., Siemann, E. and Zou, J. W. 2016. Soil respiration and litter decomposition increased following perennial forb invasion into an annual grassland. Pedosphere. 26(4): 567-576. |
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