AUTHOR=Jia Pu , Wang Jiayi , Liang Haolin , Wu Zhuo-hui , Li Fenglin , Li Weihua 

TITLE=Replacement control of Mikania micrantha in orchards and its eco-physiological mechanism

JOURNAL=Frontiers in Ecology and Evolution

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2022.1095946

DOI=10.3389/fevo.2022.1095946

ISSN=2296-701X

ABSTRACT=<p><italic>Mikania micrantha</italic> is one of the most notorious invasive weeds in south China, especially in orchard habitats. Based on the principle of niche competition, screening plants with strong competitiveness and managing vacant niches through natural alternative methods (replacement control) were expected to achieve sustainable ecological management of invasive species. To this end, two legumes, <italic>Desmodium heterocarpon</italic> and <italic>Senna tora</italic>, were selected to conduct field competition experiments with <italic>M. micrantha</italic> to investigate the interspecific competitiveness of these two legumes and <italic>M. micrantha</italic> from the aspects of adaptability to low light and response to drought stress. We found that the relative interaction indexes of <italic>D. heterocarpon</italic> and <italic>S. tora</italic> to <italic>M. micrantha</italic> were both negative and the competitive inhibition of <italic>S. tora</italic> on <italic>M. micrantha</italic> was higher than that of <italic>D. heterocarpon</italic>. Compared with <italic>M. micrantha</italic>, <italic>D. heterocarpon</italic> and <italic>S. tora</italic> have higher photosynthetic efficiency and lower dark respiration efficiency under low-light conditions, thus maintaining positive plant carbon balance capacity in the low-light understory and becoming more shade-tolerant. Besides, the water stress experiment found that <italic>M. micrantha</italic> had the lowest tolerance to drought stress, followed by <italic>S. tora</italic>, and <italic>D. heterocarpon</italic> was the most drought tolerant. These results showed that <italic>D. heterocarpon</italic> and <italic>S. tora</italic> can effectively prevent and control <italic>M. micrantha</italic>, mainly due to their higher competitiveness, shade tolerance, and drought tolerance. The control effect of <italic>D. heterocarpon</italic> is better than that of <italic>S. tora</italic> which is an alien species. Therefore, we believed that the replacement control of the invasive weed <italic>M. micrantha</italic> by <italic>D. heterocarpon</italic> is expected to be a sustainable ecological management strategy for <italic>M. micrantha</italic> biocontrol in the dryland orchard habitat. These findings provide a theoretical basis for the selection of species for alternative control in the future and provide new ideas for solving the problem of repeated regeneration in the existing <italic>M. micrantha</italic> control process.</p>