Weak conspecific feedbacks and exotic dominance in a species-rich savannah

Proceedings of the Royal Society B: Biological Sciences - Tập 278 Số 1720 - Trang 2939-2945 - 2011
Andrew S. MacDougall1, Matthias C. Rillig2, John N. Klironomos3
1Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
2Institut für Biologie, Freie Universität Berlin, Berlin 14195, Germany
3Biology and Physical Geography Unit, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada, V1V 1V7

Tóm tắt

Whether dominance drives species loss can depend on the power of conspecific self-limitation as dominant populations expand; these limitations can stabilize competitive imbalances that might otherwise cause displacement. We quantify the relative strength of conspecific and heterospecific soil feedbacks in an exotic-dominated savannah, using greenhouse trials and field surveys to test whether dominants are less self-suppressed, highly suppressive of others or both. Soil feedbacks can impact plant abundance, including invasion, but their implications for coexistence in invader-dominated systems are unclear. We found that conspecific feedbacks were significantly more negative than heterospecific ones for all species including the dominant invaders; even the rarest natives performed significantly better in the soils of other species. The strength of these negative feedbacks, however, was approximately 50 per cent stronger for natives and matched their field abundance—the most self-limited natives were rare and narrowly distributed. These results suggest that exotics dominate by interacting with natives carrying heavier conspecific feedback burdens, without cultivating either negative heterospecific effects that suppress natives or positive ones that accelerate their own expansion. These feedbacks, however, could contribute to coexistence because all species were self-limited in their own soils. Although the net impact of this feedback stabilization will probably interact with other factors (e.g. herbivory), soil feedbacks may thus contribute to invader dominance without necessarily being detrimental to species richness.

Từ khóa


Tài liệu tham khảo

10.1146/annurev.ecolsys.31.1.343

10.1126/science.1190772

10.1086/285357

Tilman D., 1988, Plant strategies and the dynamics and structure of plant communities

10.1038/35006630

10.7208/chicago/9780226101811.001.0001

10.1126/science.199.4335.1302

10.1038/nature07248

10.1111/j.1461-0248.2007.01115.x

10.1038/nature08251

10.1111/j.1365-2745.2009.01514.x

10.1086/657438

Yelenik S. G., The role of plant–soil feedbacks in driving native species recovery, Ecology

10.1016/S0169-5347(02)02499-0

10.1111/j.1461-0248.2006.00996.x

10.2307/2960528

10.1111/j.1461-0248.2007.01017.x

10.1111/j.1365-2745.2009.01578.x

10.1016/j.tree.2010.05.004

10.1111/j.1461-0248.2007.01030.x

10.1038/417067a

10.1007/BF00333217

10.1038/362053a0

10.1038/nature09273

10.1890/07-2056.1

10.1111/j.1461-0248.2008.01209.x

10.1038/nature07474

10.1111/j.1461-0248.2006.00949.x

10.1111/j.1365-2745.2009.01574.x

10.1111/j.1365-2745.2007.01282.x

10.1890/07-2144.1

10.1111/j.0022-0477.2004.00953.x

10.1371/journal.pbio.0040140

10.1038/nature02322

10.1890/04-1733

10.1016/j.biocon.2008.07.019

10.1111/j.1600-0706.2009.17503.x

10.1890/0012-9658(2006)87[1831:DCASPO]2.0.CO;2

10.1007/BF01373392

10.1016/S0929-1393(03)00073-8

10.1111/j.1365-2389.2008.01016.x

SAS. 2009 JMP 8 user guide 2nd edn. Cary NC: SAS Institute.

10.2307/1941601

10.1046/j.1469-8137.2003.00714.x

10.1038/35005072

10.1073/pnas.0903244106

10.1890/08-0419.1

10.1023/A:1013972403293

10.1890/04-0669

10.1098/rspb.2006.3660

10.1126/science.1083245

Callaway R. M., 2007, Positive interactions and interdependence in plant communities.

10.2307/1940675

10.1007/BF00326095

10.1146/annurev.py.32.090194.002443

10.1890/08-0729.1

10.1890/08-1380.1

10.1890/08-0435.1

10.1890/09-0204.1

10.1111/j.1600-0706.2009.17698.x

10.1007/s11258-009-9655-7

Thông tin
Thông tin xuất bản

Proceedings of the Royal Society B: Biological Sciences

Tập 278 Số 1720

2939-2945

Thông tin tác giả