浙江滨海湿地互花米草生长性状对土壤化学因子的响应

Response of Spartina alterniflora Growth to Soil Chemical Properties in Coastal Wetland of Zhejiang

[目的]比较浙江滨海湿地互花米草的生长差异,探析土壤主要化学因子对其生长的影响,为滨海湿地互花米草有效管控提供参考。[方法]以杭州湾、象山港和乐清湾作为采样地点,调查测定互花米草种群密度、株高、基径和地上生物量等生长性状指标以及土壤pH、水溶性盐分、有机碳、全氮、全磷、有效氮和有效磷等化学因子,对各个生长性状指标及土壤化学因子进行统计分析。[结果](1)互花米草种群密度、株高、基径、单株地上生物量及样方地上生物量均为杭州湾>象山港>乐清湾,乐清湾与象山港互花米草个体较矮小,种群较稀疏且两地差异不显著,而杭州湾互花米草则显著高于其它两地(P<0.01)。(2)乐清湾与象山港湿地土壤养分及盐度较高且两地差异不显著,而杭州湾湿地则显著低于其它两地(P<0.01)。(3)影响互花米草生长最主要的土壤化学因子是水溶性盐分,其次是土壤全氮、有效磷及pH。[结论]土壤化学因子影响浙江滨海湿地互花米草生长,土壤盐分浓度、养分含量在一定范围内促进互花米草生长,而高盐高养分则可能抑制其生长。

[Objective] The growth differences of Spartina alterniflora in coastal wetland of Zhejiang Province were compared to identify the influence of soil chemical properties on the growth of S. alterniflora and provide reference for management and control of S. alterniflora in coastal wetland. [Method] Field investigation and the related laboratory tests were carried out in Hangzhou Bay, Xiangshan Port and Yueqing Bay. The growth characteristics indexes of S. alterniflora population density, plant height, basal stem diameter and aboveground biomass, as well as soil chemical properties such as soil pH, water soluble salt, soil organic carbon, total nitrogen, total phosphorus, available nitrogen and available phosphorus were measured. Single factor ANOVA, correlation analysis, and path analysis were applied to analyze the relationship between soil chemical properties and the growth traits of S. alterniflora in sampling sites. [Result](1) The population density, plant height, basal stem diameter and plant biomass of S. alterniflora followed the order of Hangzhou Bay > Xiangshan Port > Yueqing Bay. There was no significant difference in growth traits between Yueqing Bay and Xiangshan Port, while the growth traits in Hangzhou Bay were significantly higher than those in the other two regions(P < 0.01).(2) There was no significant difference in soil nutrient contents and soil salinity between Yueqing Bay and Xiangshan Port, significantly higher than those in Hangzhou Bay(P <0.01).(3) The most important soil chemical properties affecting the growth of S. alterniflora was soil water-soluble salt and followed by soil total nitrogen, available phosphate and pH. [Conclusion] The growth of S. alterniflora is affected by soil chemical properties in coastal wetland of Zhejiang Province. Soil salinity and nutrient content in a certain range can promote the growth of S. alterniflora, while high salt and high nutrient content may inhibit its growth.