Allelopathic effects of common exotic plants on soil-conserving native grasses in Taiwan
Allelopathic effects of common exotic plants on soil-conserving native grasses in Taiwan
- Author(s) Hao-Jen Huang,, Chi-Chou Chiu, Ming-Chien Lin, Che-Hui Lin, Je-Chiuan Ye
- Year: 2025
- Month: May
- Volume: 65
- Pages: 21-34
Invasive plant species, such as Mikania micrantha (M. micrantha), Leucaena leucocephala (L. leucocephala) and Mimosa pigra (M. pigra), often outcompete native vegetation, leading to biodiversity loss and ecological imbalance. These invasive species can negatively impact ecosystems by altering habitat structure, modifying nutrient cycling, and suppressing the growth of native plants, which can have significant ecological and economic consequences, particularly in agriculture. This study investigates the allelopathic effects of three invasive species on five soil-conserving grasses native to Taiwan: Axonopus affinis Chase (A. affinis), Cynodon dactylon (C. dactylon), Dichondra repens (D. repens), Paspalum notatum (P. notatum) and Eremochloa ophiuroides (E. ophiuroides). Results indicate that the root growth of A. affinis, C. dactylon, and D. repens was inhibited by extracts of M. micrantha, while P. notatum and E. ophiuroides showed no significant effects. In contrast, the root growth of all five grass species was inhibited by the L. leucocephala extracts. For M. pigra, the root growth of A. affinis, E. ophiuroides, and D. repens was inhibited, while C. dactylon and P. notatum were unaffected. Interestingly, the inhibitory effects were correlated with increased peroxidase (POD) activity in the plants, suggesting a potential mechanism of resistance or tolerance in some species, particularly P. notatum. This grass species exhibited notable resistance to allelochemicals from M. micrantha and M. pigra but appeared more vulnerable to those from L. leucocephala. The study also examined the effects of benzoic acid, the primary allelochemical in M. micrantha, and mimosine, the key compound in L. leucocephala and M. pigra. The growth inhibition caused by these compounds mirrored the effects of the plant extracts, highlighting the allelopathic potential of benzoic acid and mimosine, which be used as a natural herbicide to protect human health. These findings provide valuable insights into the complex interactions between invasive plant species and native grasses, particularly the potential resistance of P. notatum to certain allelochemicals, which could inform strategies for managing invasive species and conserving native vegetation in Taiwan.
