Soil history as a primary control on plant invasion in abandoned agricultural fields
Article first published online: 1 JUN 2006
Journal of Applied Ecology
Volume 43, Issue 5, pages 868–876, October 2006
How to Cite
KULMATISKI, A., BEARD, K. H. and STARK, J. M. (2006), Soil history as a primary control on plant invasion in abandoned agricultural fields. Journal of Applied Ecology, 43: 868–876. doi: 10.1111/j.1365-2664.2006.01192.x
- Issue published online: 1 JUN 2006
- Article first published online: 1 JUN 2006
- Received 27 July 2005; final copy received 20 March 2006 Editor: Phil Hulme
- exotic invasion;
- native plant;
- plant–soil feedback;
- soil microbial community;
- 1Abandoned agricultural (AA) fields are often invaded by exotic plants. This observation has been difficult to explain because agricultural practices change nearly every aspect of an ecosystem. Restoring native plants to AA fields is likely to require a prioritized understanding of the many mechanisms through which agriculture encourages exotic and discourages native plant growth.
- 2Using 660 experimental plots in three sites in Methow Valley, Washington, USA, we determined the relative role of neighbour removal, propagule addition, plant–soil feedback, soil disturbance and fungal restriction to explain why exotics cover 38% of the ground in AA fields and 3% of the ground in non-agricultural (NA) fields.
- 3After three growing seasons, neighbour removal improved exotic growth from 3% to 11% cover in NA fields but had no effect in AA fields. Propagule addition did not increase exotic growth above natural recruitment. Differences in soil history, a proxy for plant–soil feedback, explained an increase in exotic growth from 9% in NA fields to 39% in AA fields. Soil disturbance improved exotic growth from 9% to 16% cover in NA fields but had no effect in AA fields. Fungicide reduced exotic growth from 39% to 28% cover in AA soils but had no effect on exotic growth in NA soils. Native plant growth never differed by more than 5% cover among treatments.
- 4Soil carbon, nitrogen (organic, inorganic and mineralization), phosphorus concentrations and fungal biomass were better associated with plant type (exotic or native) than agricultural history, suggesting that exotics facilitated their own growth by maintaining small beneficial fungal populations and fast nutrient cycling rates.
- 5Synthesis and application. Soil history was more important than neighbour removal in determining exotic and native plant distributions. Where exotics rely on plant–soil feedback or legacies of agricultural disturbance, native plant restoration may require soil-based management. In these cases, changing mycorrhizal fungal abundance, increasing soil pathogen loading and slowing nutrient cycling rates may help restore native plants to invaded fields.