Li Qiang, Liu Xiao, Liu Ke, Ren Hai, Jian Shuguang, Lu Hongfang, Cheng Yuanhao, Zou Qingchi, Huang Yao
School of Tropical Medicine, Hainan Medical University, Haikou, 571199, China.
School of Geography and Tourism, Qilu Normal University, Jinan, 250200, China.
BMC Plant Biol. 2025 Apr 21;25(1):504. doi: 10.1186/s12870-025-06556-0.
Plant invasion affects plant community composition, biodiversity, and nutrient cycling in terrestrial ecosystems, particularly in vulnerable ecosystems. As an invasive parasitic plant, Cassytha filiformis has caused extensive damage to the native vegetation of the Paracel Islands. However, the effects of C. filiformis invasion on litter decomposition and nutrient release in native plant communities remain unclear. We conducted an in-situ decomposition experiment in native plant communities on a coral island to explore the litter decomposition dynamics varying across enzyme activities, soil properties and C. filiformis invasive degrees.
The mass loss of litter was determined during the decomposition process. The data showed that litter mass loss under severe invasion was significantly lower than in uninvaded sites after nine months of decomposition. The invasion of C. filiformis accelerated the nitrogen release and lignin decomposition with increased litter quality and polyphenol oxidase activity. Besides, soil phosphorus availability and potassium content also induced the oxidase activity. Meanwhile, the decomposition of litter organic carbon was delayed because β-1, 4-glucosidase activity was low in the first six months. Besides, peroxidase activity maintained a high level in invasive plots, indicating that the residues of C. filiformis may have allelopathy.
Our results suggested that the invasion of C. filiformis accelerated litter mass loss and element release on coral islands by regulating litter quality and enzyme activity. However, the short-term rapid litter decomposition may result in nutrient loss, which is not conducive to the growth of native plants.
植物入侵会影响陆地生态系统中的植物群落组成、生物多样性和养分循环，在脆弱生态系统中尤为如此。无根藤作为一种入侵寄生植物，已对西沙群岛的原生植被造成了广泛破坏。然而，无根藤入侵对原生植物群落凋落物分解和养分释放的影响仍不清楚。我们在珊瑚岛的原生植物群落中进行了一项原位分解实验，以探究凋落物分解动态如何随酶活性、土壤性质和无根藤入侵程度而变化。
在分解过程中测定了凋落物的质量损失。数据表明，经过九个月的分解，重度入侵下的凋落物质量损失显著低于未入侵地点。无根藤的入侵加速了氮的释放和木质素的分解，同时提高了凋落物质量和多酚氧化酶活性。此外，土壤有效磷和钾含量也诱导了氧化酶活性。与此同时，凋落物有机碳的分解被延迟，因为在前六个月β-1,4-葡萄糖苷酶活性较低。此外，过氧化物酶活性在入侵地块中保持较高水平，这表明无根藤的残体可能具有化感作用。
我们的结果表明，无根藤的入侵通过调节凋落物质量和酶活性，加速了珊瑚岛上凋落物的质量损失和元素释放。然而，凋落物的短期快速分解可能导致养分流失，不利于原生植物的生长。
