Wang Daobo, Huang Wei, Liang Ruwen, Li Fusheng
Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Guangxi colleges and universities Key Laboratory of Exploitation and Protection of Beibu Gulf Marine Biological Resources, College of Resources and Environment, Qinzhou University, Guangxi, China.
College of Agriculture, Guangxi University, Guangxi, China.
PLoS One. 2016 Dec 30;11(12):e0168951. doi: 10.1371/journal.pone.0168951. eCollection 2016.
Since Spartina alterniflora (simplified as Spartina) has strong ecological competitiveness and rapid growth, it has been introduced and living in the coastal wetland regions of China for more than 30 years. Taking coastal wetland in the Beibu Gulf of south China as an example, the effects of Spartina invasion on soil quality were investigated to provide scientific basis for soil management.
The soil quality of six different coastal wetlands, i.e. mangrove (vegetation coverage is above 95%), mangrove- Spartina ecotones (vegetation coverage is above 95%), sparse mangrove (vegetation coverage is 10%-20%), sparse mangrove- Spartina ecotones (vegetation coverage is about 80%), Spartina (vegetation coverage is about 80%) and bare beach (no plants), were analyzed using the following indicators: pH, cation exchange capacity, contents of total nitrogen, total phosphorus and organic carbon, microbial biomass carbon, microbial biomass nitrogen, microbial carbon / organic carbon, and activities of urease, acid phosphatase, invertase, polyphenol oxidase and catalase.
The results showed that compared to mangrove wetland, most indicators in the mangrove-Spartina wetland showed a decline tendency except pH value, and the contents of total phosphorus and organic carbon, microbial biomass carbon and soil microbial biomass nitrogen, and the activities of acid phosphatase and invertase were significantly reduced (P<0.05). Compared to sparse mangrove wetland and bare beach, the Spartina invasion wetland (sparse mangrove-Spartina wetland and Spartina wetland) had higher contents of total nitrogen, total phosphorus and organic carbon, microbial biomass carbon, microbial biomass nitrogen, cation exchange capacity and the activities of urease and acid phosphatase, so soil quality in the sparse mangrove wetland and bare beach was significantly improved. Factor Analysis and PCA also showed that: the quality of mangrove wetland soil is better than that of mangrove-Spartina ecotones wetland soil; the quality of sparse mangrove-Spartina ecotones wetland soil is better than that of sparse mangrove wetland soil; the quality of Spartina wetland soil is better than that of bare beach wetland soil.
CONCLUSIONS/SIGNIFICANCE: Therefore, in the invaded Beibu Gulf wetland ecosystems of south China, for the mangrove wetlands where the productivity of native plant was higher than that of Spartina, the Spartina invasion can cause soil degradation significantly and it must be strictly controlled, while for sparse mangrove wetland and bare beach where the productivity of native plant was lower than that of Spartina, Spartina invasion can improve the soil quality. Thus our study may help to better understand the effect of plant invasion.
由于互花米草具有很强的生态竞争力且生长迅速，已在中国沿海湿地地区引种并生长了30多年。以中国南部北部湾的沿海湿地为例，研究互花米草入侵对土壤质量的影响，为土壤管理提供科学依据。
分析了六种不同沿海湿地的土壤质量，即红树林（植被覆盖率高于95%）、红树林-互花米草交错带（植被覆盖率高于95%）、稀疏红树林（植被覆盖率为10%-20%）、稀疏红树林-互花米草交错带（植被覆盖率约为80%）、互花米草（植被覆盖率约为80%）和裸滩（无植物），使用以下指标：pH值、阳离子交换量、总氮、总磷和有机碳含量、微生物生物量碳、微生物生物量氮、微生物碳/有机碳，以及脲酶、酸性磷酸酶、转化酶、多酚氧化酶和过氧化氢酶的活性。
结果表明，与红树林湿地相比，除pH值外，红树林-互花米草湿地的大多数指标呈下降趋势，总磷和有机碳含量、微生物生物量碳和土壤微生物生物量氮以及酸性磷酸酶和转化酶的活性显著降低（P<0.05）。与稀疏红树林湿地和裸滩相比，互花米草入侵湿地（稀疏红树林-互花米草湿地和互花米草湿地）的总氮、总磷和有机碳含量、微生物生物量碳、微生物生物量氮、阳离子交换量以及脲酶和酸性磷酸酶的活性较高，因此稀疏红树林湿地和裸滩的土壤质量得到显著改善。因子分析和主成分分析还表明：红树林湿地土壤质量优于红树林-互花米草交错带湿地土壤质量；稀疏红树林-互花米草交错带湿地土壤质量优于稀疏红树林湿地土壤质量；互花米草湿地土壤质量优于裸滩湿地土壤质量。
结论/意义：因此，在中国南部被入侵的北部湾湿地生态系统中，对于本地植物生产力高于互花米草的红树林湿地，互花米草入侵会导致土壤显著退化，必须严格控制，而对于本地植物生产力低于互花米草的稀疏红树林湿地和裸滩，互花米草入侵可以改善土壤质量。因此，我们的研究可能有助于更好地理解植物入侵的影响。
