The invasive stoloniferous clonal plant Alternanthera philoxeroides outperforms its co-occurring non-invasive functional counterparts in heterogeneous soil environments - invasion implications.

Tong Wang,Linlin Miao,Chunhua Liu,Dan Yu,Jiangtao Hu

doi:10.1038/srep38036

Abstract

Environmental heterogeneity is considered to play a defining role in promoting invasion success, and it favours clonal plants. Although clonality has been demonstrated to be correlated with the invasion success of several species of clonal invasive plants in heterogeneous environments, little is known about how the spatial scale of heterogeneity affects their performance. In addition, the factors that distinguish invasive from non-invasive clonal species and that enhance the invasive potential of clonal exotic invaders in heterogeneous environments remain unclear. In this study, we compared several traits of a noxious clonal invasive species, Alternanthera philoxeroides, with its co-occurring non-invasive functional counterparts, the native congener Alternanthera sessilis, the exotic Myriophyllum aquaticum and the native Jussiaea repens, in three manipulative substrates with different soil distribution patterns. We found that the invasive performance of A. philoxeroides was not enhanced by heterogeneity and that it was generally scale independent. However, A. philoxeroides showed some advantages over the three non-invasives with respect to trait values and phenotypic variation. These advantages may enhance the competitive capacity of A. philoxeroides and thus promote its invasion success in heterogeneous environments.

Highlights

Size and belowground traits such as root mass ratio (RMR) and R/S ratio compared with their co-occurring non-invasive species[19,20,21]
Environmental heterogeneity is considered to favour clonal growth because stoloniferous clonal plants can display a variety of clonal functional traits that allow them to cope with environmental heterogeneity[42]
Clonal functional traits such as foraging behaviour, clonal integration and spatial division of labour are expected to benefit the performance of clonal plants in heterogeneous environments because they facilitate the exploitation of benign resources, internal exchange of resources and spread of risk[9,10,11]

Summary

Introduction

Size and belowground traits such as root mass ratio (RMR) and R/S ratio compared with their co-occurring non-invasive species[19,20,21]. Invasive clonal plants likely possess a stronger potential of clonality (e.g., clonal integration, spatial division of labour) than do co-occurring, non-invasive clonal species[8] This stronger potential is expected to facilitate the integration of unevenly distributed resources by invasive clonal plants in heterogeneous environments and enhance their performance[10,13,14,15,22]. These trait value advantages may promote the rapid colonization and efficient establishment of invasive species in novel and heterogeneous environments. The correlation between clonal performance and the spatial distribution of soil was studied in a stoloniferous weed species that is a detrimental invasive in many regions worldwide, – Alternanthera philoxeroides. Compared with the three non-invasive functional counterparts, the invasive A. philoxeroides displays some trait advantages in the presence of different soil distribution patterns

Methods

Results

Conclusion