The impact of hemiparasitic plant litter on decomposition: direct, seasonal and litter mixing effects
Article first published online: 8 DEC 2004
Journal of Ecology
Volume 93, Issue 1, pages 87–98, February 2005
How to Cite
QUESTED, H. M., CALLAGHAN, T. V., CORNELISSEN, J. H. C. and PRESS, M. C. (2005), The impact of hemiparasitic plant litter on decomposition: direct, seasonal and litter mixing effects. Journal of Ecology, 93: 87–98. doi: 10.1111/j.0022-0477.2004.00951.x
- Issue published online: 8 DEC 2004
- Article first published online: 8 DEC 2004
- Received 27 May 2004 revision accepted 29 September 2004 Handling Editor: David Gibson
- ecosystem processes;
- functional groups;
- hemiparasitic plants;
- litter mixtures;
- nutrient cycling;
- plant–soil interactions;
- seasonal decomposition;
- winter processes
- 1Nutrient-rich litter of hemiparasites (and N-fixers) has the potential to influence ecosystem-level decomposition and nutrient cycling, which may be important in ecosystems where productivity is nutrient limited. This influence may be both direct, and indirect via impacts on the decomposition of other species’ litters in mixed-species litter layers.
- 2We investigate the importance of these direct and indirect effects of sub-arctic hemiparasite litter in a litterbed study and a field litterbag experiment, and compare these data with those from a microcosm study also involving litter mixtures.
- 3Field-placed litterbags demonstrate for the first time the direct importance of hemiparasite litter on decomposition and nutrient cycling in a field setting: litter of the hemiparasite Bartsia alpina lost 18 times more N over 2 years than Betula nana litter.
- 4The majority of this N was released during the growing season, strongly supporting the proposal that hemiparasites can have a substantial direct impact on nutrient availability to other plants. The short spring and autumn periods were important for litter mass and N dynamics, with consequences for predicting effects of environmental change.
- 5However, hemiparasite litter did not indirectly affect the decomposition rate or nutrient release from litter mixtures in field-placed litterbags. Furthermore, the direction and magnitude of litter mixing effects on mass loss varied strongly between methods; interactions were absent or negative in the litterbed, non-significant in field litterbags and positive in microcosms.
- 6We thereby demonstrate the importance of the decomposition environment, rather than species-specific litter quality, in determining litter-mixing interactions, with implications for evaluating the impact of particular species on ecosystem carbon and nutrient fluxes via litter mixing
- 7We conclude that hemiparasites have a particular functional role in sub-arctic heath systems: in effect they ‘short circuit’ generally slow nutrient cycles, with potential impacts on resource patchiness and local scale biodiversity.