Effects of soil substrate heterogeneity and moisture on interspecific competition between Alternanthera philoxeroides and four native species. (23rd May 2016)

• Record Type: Journal Article
• Authors: Liu, Lu; Dong, Bi-Cheng; Alpert, Peter; Yu, Fei-Hai
• Is Part Of: Journal of plant ecology. Volume 10:Number 3(2017:Jun.)
• Page Start: 528
• Page End: 537
• Publication Date: 2016-05-23
• Subjects: alligator weed -- clonal plant -- competitive effect -- competitive response -- soil heterogeneity -- soil moisture -- foraging behavior.; Plant ecology -- Periodicals; Phytogeography -- Periodicals; 581.705
• DOI: 10.1093/jpe/rtw052
• Languages: English
• ISSNs: 1752-9921

Abstract

Abstract: Aims: Clonal plant species have the potential for high relative performance in heterogeneous environments, and this might increase the competitive ability and invasiveness of introduced clonal plant species. It was hypothesized that clonal species whose performance responds more to heterogeneity of a resource have higher competitive ability in habitats where this resource is more heterogeneous and that this relationship is stronger when other resources are less limiting. Methods: To test these hypotheses, the perennial clonal herb Alternanthera philoxeroides, which is invasive in China, was grown alone or with each of four clonal perennial, co-occurring herbs native to China, i.e. Alternanthera sessilis, Cynodon dactylon, Hemarthria altissima and Wedelia chinensis . Plants were given homogeneous or heterogeneous soil substrate crossed with low and high levels of soil moisture. Important Findings: Effects of heterogeneity on the accumulation of mass and ramets and on competitive effect and response of A. philoxeroides differed between native species and interacted with effects of soil moisture. A. philoxeroides reduced the final total mass or ramet number of the native species except A. sessilis, and the negative competitive effects on H. altissima and C. dactylon were more pronounced in heterogeneous than in homogeneous soil. Competitive response of A. philoxeroides was more negative to A. sessilis than to the other native species. Across native species, the competitive response of A. philoxeroides was more negative in heterogeneous than in homogeneous soils at low moisture level, but the reverse was true at high moisture level. Results do not consistently support either hypothesis, but do suggest that competitive ability can be partly explained by individual species traits such as size, and that some competitive effects and responses are emergent properties of interspecific interactions.