Inhibition of an invasive plant (Mikania micrantha H.B.K.) by soils of three different forests in lower subtropical China

Abstract

Biological invasion represents one of the most serious threats to biodiversity, and invasion ecology research has become one of the central issues of contemporary environmental science. However, the relative role of soil development as correlated with succession in influencing variation in invasion resistance has seldom been examined. We hypothesized that the invasion potential of exotic plants depends on soil conditions. In this study, we explored variation among soils of three forest types in their resistance to invasion by Mikania micrantha H.B.K. in lower subtropical China; this species is one of the top ten most invasive weeds in the world. In model systems of soils from different forests, M. micrantha performed worst on undisturbed late-successional stage forest (monsoon evergreen broadleaf forest, MEBF) soils and did not appear to take advantage of abundant soil nutrients. These results could reflect that a potential inhibitory effect was driven by MEBF soil. Plant litter is an important component of soils, litter bioassay and addition experiments demonstrated native plant species from different forests differentially confer invasion resistance and affect the performance of exotic plants. Naturally, other factors such as the relative abundances of nutrients, microbial feedbacks, could have contributed to these results as well. Our results challenge the notion that forests are not immune to invasion and suggest that maintaining late-successional plant communities in lower subtropical China, which could be related to increased productivity and stability, should be a primary objective of land managers.

Soil fungi of three native tree species inhibit biomass production and shift biomass allocation of invasive Mikania micrantha Kunth

“…Resistance to alien plant invasion might result from the strong effects of a relatively small number of native species [32], such as in HF, CB, and MT [9]. Our results support a hypothesis of soil biotic resistance [33,34], and are congruent with a study by Hou et al [35], which showed MM was inhibited when exposed to soils from three different forests located in lower subtropical China.…”

The Effects of Soils from Different Forest Types on the Growth of the Invasive Plant Phytolacca americana

“…Some evidence has suggested that allelopathic native plants play a role in inhibiting the growth of invaders [37][38][39]. We found that the allelopathic activity in natural forest soil and litter inhibited the growth of P. americana but that RP soil promoted its growth (Figures 2 and 3), which seems to confirm our second hypothesis: Allelopathy of natural forests inhibits P. americana growth and that of the R. pseudoacacia plantation promotes its growth.…”

“…Ning et al [37] provided evidence that in grassland communities allelopathic native grasses increased community resistance to introduced plants. However, this study did not produce results for succession-associated allelopathy consistent with Hou et al [39], who found that late-successional stage forest soils have stronger allelopathy than early-successional stages. Although litter leachate from F3 inhibited P. americana growth stronger than that of the other forests (Figure 3), the allelopathic effects of F3 and F4 soils on the growth of this plant were not significant ( Figure 2).…”

“…We found that the allelopathic activity in natural forest soil and litter inhibited the growth of P. americana but that RP soil promoted its growth (Figures 2 and 3), which seems to confirm our second hypothesis: Allelopathy of natural forests inhibits P. americana growth and that of the R. pseudoacacia plantation promotes its growth. Similarly, Hou et al [39] found that monsoon evergreen broadleaf forest soil has strong allelopathic activity towards invasive plants in lower subtropical China. Ning et al [37] provided evidence that in grassland communities allelopathic native grasses increased community resistance to introduced plants.…”

Native Expanding <i>Merremia boisiana</i> Is Not More Allelopathic than Its Non-Expanding Congener <i>M. vitifolia</i> in the Expanded Range in Hainan

“…The original and expanded ranges of M. boisiana are quite near and there are no strong natural barriers as compared to that between China and America, and plants in the two ranges may have already preadapted to each other. Similarly, two recent studies found that allelopathy from some native plants in natural forests could inhibit the growth of exotic invasive M. micrantha that originated from South America [18], but did not inhibit the growth of M. boisiana [19]. Our results indicate that the mechanisms underlying the explosion of M. boisiana in the expanded range might not be due to its higher allelopathic effects as compared to non-expanding native congeneric species, although the weed does have allelopathic effects.…”