|ZENG Jing,LI Xu,HOU Zhiyong,XIE Yonghong.Soil enzyme activities in three typical plant communities in Lake Dongting wetland with typical hygrophilous vegetations. J. Lake Sci.2017,29(4):907-913. DOI:10.18307/2017.0414
|调查了洞庭湖湿地典型植物群落（短尖苔草（Carex brevicuspis）、南荻（Triarrhena sacchariflora）、辣蓼（Polygonumhy dropiper））洪水期前后（5、10月）两次表层土壤酶活性及土壤养分性状. 结果表明：3种典型群落之间具有明显的土壤养分性状及土壤酶活差异. 辣蓼群落具有相对较高的土壤有机质、全氮、全磷、速效磷含量，短尖苔草群落次之，而南荻群落的土壤养分含量最低. 3种典型植物群落的土壤有机质、全氮、全磷含量均表现为5月高于10月，土壤速效磷、速效钾洪水期前后无显著差异. 辣蓼群落的蔗糖酶活性明显高于其他2个群落；3个群落脲酶活性均表现为10月高于5月，南荻、辣蓼群落有显著差异. 磷酸酶以南荻群落最高，短尖苔草群落5月显著高于10月，南荻群落则10月显著高于5月；短尖苔草、南荻群落过氧化氢酶活性显著高于辣蓼群落，短尖苔草群落5月与10月间有显著差异，其余2个群落无显著差异. 相关分析表明：脲酶活性与土壤养分含量关系不密切；蔗糖酶活性与土壤有机质、全磷、全氮及速效磷素含量均呈显著正相关. 总体上，洞庭湖典型湿地植物群落显示了较为明显的土壤理化状况以及土壤酶活差异；同时也显示了季节性差异. 相对而言，辣蓼群落土壤具有较快的物质循环与转化代谢速率，对于氮、磷等污染物具有较高的转化作用，而短尖苔草、南荻群落低于辣蓼群落，这可能与二者较低的土壤有机质以及氮磷养分积累有关.
|关键词: 洞庭湖 湿地植物群落 土壤酶 土壤养分
|Soil enzyme activities in three typical plant communities in Lake Dongting wetland with typical hygrophilous vegetations
ZENG Jing, LI Xu, HOU Zhiyong, XIE Yonghong
Lake Dongting Station for Wetland Ecosystem Observation and Research, Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, P.R.China
|Soil nutrients and enzyme activities in surface soils covered by three typical hygrophilous vegetation communities(Carex brevicuspis, Triarrhena sacchariflora and Polygonumhy dropiper) in Lake Dongting wetland were investigated before (May) and after (October) flooding. Results showed that significant difference in nutrients and enzyme activities was found among soils with the three vegetation communities. Soils covered by P. dropiper had the highest soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP) contents, followed by the soils covered by C. brevicuspis, and by T. sacchariflora. Soil organic matters, TN and TP of the three vegetation types were all higher in May than those in October, while no difference existed between different sampling time for available phosphorus(A-P) and available potassium. For soil enzyme activities, sucrase activity was significantly higher in P. hydropiper community that those in the other two vegetation types; urease activity was generally higher in October than those in May, and showed significantly differences in P. hydropiper and T. sacchariflora communities; Phosphatase activity was highest in T. sacchariflora community and was significantly higher in October than those in May, while in C. brevicuspis community, the Phosphatase activity was higher in May than those in October; Catalase activity was a bit higher in C. brevicuspis and T. sacchariflora communities that those in P. hydropiper community, and moreover it varied significantly with sampling time in C. brevicuspis community. Correlation analysis indicated that sucrase activity was significantly and positively associated with soil nutrients, including SOC, TP, A-P, and TN. It was suggested by correlation analysis that urease activity was not related to soil nutrients, while sucraseactitity was positively correlated to soil nutrient contents (including SOC, TP, A-P and TN). Overall, soils covered by different vegetation types varies greatly in the physicochemical features and enzyme activities.
|Key words: Lake Dongting hygrophilous vegetation soil enzyme soil nutrients