Interactions between seedlings of the invasive tree Ailanthus altissima and the native tree Robinia pseudoacacia under low nutrient conditions

Abstract

The allelopathic effect of A. altissima and the nitrogen fixing ability of R. pseudoacacia make the interaction between these two species important to community dynamics. A replacement series greenhouse experiment was used to investigate the type of interaction between seedlings of A. altissima and R. pseudoacacia at high and low soil nutrition states. Also, seeds of A. altissima from its native (China) and invasive ranges (USA) were used to compare the effect of the different seed sources on the interaction with R. pseudoacacia. Robinia pseudoacacia was the better competitor. The presence of A. altissima significantly inhibited nodulation of R. pseudoacacia roots. In summary, in low nutrient early succession sites, seedlings of R. pseudoacacia and A. altissima will coexist and R. pseudoacacia will be the better competitor. However, A. altissima can increase its competitive ability by inhibiting nitrogen fixation by R. pseudoacacia. Differences between the competitive ability of the Chinese and US seed lots of A. altissima did not support the rapid evolution theory for invasive species success.

Keywords:

• Belowground competition
• competition for nutrients
• facilitation
• invasive species
• nodulation
• replacement series

Acknowledgements

Thanks to Jacob Barney, Lisa Belden, Cynthia Huebner and Robert Jones for comments on earlier drafts of this manuscript. Thanks to Cynthia Huebner for the A. altissima seeds from the invaded range. Thanks to Austin Jackson, Nigel Temple, Tatpong Tulyanon and Deborah Wiley for help harvesting the plants.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed at 10.1080/17429145.2015.1070208.

Additional information

Funding

This work was supported by the USDA Joint Venture agreement [grant number 11-1480-01, 2011–2015]: the Institute for Critical Technology and Applied Science at Virginia Tech and the Department of Biological Sciences, Virginia Tech.