杭州湾潮滩湿地土壤碱性磷酸酶活性分布及其与磷形态的关系

以杭州湾潮滩作为研究区域，对土壤中碱性磷酸酶活性、磷形态、有机磷细菌数量及理化性质的时空分布特征进行分析，揭示碱性磷酸酶活性与磷形态分布及转化的关系. 结果表明，杭州湾潮滩湿地土壤中碱性磷酸酶活性具有显著的时空差异，总体表现为7月最高（38. 59~104.74 mg·kg^-1·h^-1），2月最低（8. 21~40.61 mg·kg^-1·h^-1），且各月之间有显著性差异（p<0.05）；不同植被型土壤碱性磷酸酶活性之间差异总体表现为芦苇（39.72~104.63 mg·kg^-1·h^-1）>互花米草（32.18~73.23 mg·kg^-1·h^-1）≈海三棱藨草（9.68~83.48 mg·kg^-1·h^-1）>光滩（8.21~49.50 mg·kg^-1·h^-1），其中光滩与其他类型土壤具有显著性差异（p<0.05）. 无机磷形态中的可交换态磷（Exch-P）、铁/铝结合态磷（Fe/Al-P）及钙结合态磷（Ca-P）的含量均表现为：5月>7月>10月> 2月，5月与2月之间具有显著性差异（p<0.05）. 有机磷形态中的活性有机磷（L-P）的含量动态变化为：7月>5月>10月>2月；中等活性有机磷（ML-P）的含量表现为：2月> 5月>10月>7月；非活性有机磷（NL-P）的含量没有明显的动态变化. 相关性分析结果显示，碱性磷酸酶活性与有机磷细菌数量呈显著的正相关关系（r=0.58，p<0.01），有机磷细菌是影响碱性磷酸酶活性的主要因素之一.土壤碱性磷酸酶活性与无机磷组分中的（Fe/Al）-P（r=0.39，p<0.05）、 有机磷组分中的L-P （r=0.37，p<0.05）、NL-P（r=0.31，p<0.05）呈正相关，潮滩湿地土壤中的NL-P是生物有效磷的潜在磷源.

Soil alkaline phosphatase activity and its relationship with phosphorus forms of Hangzhou Bay Intertidal Wetland

The temporal and spatial distribution of alkaline phosphatase activity, phosphorus fractions, the number of organic phosphate bacteria and physicochemical properties of the soils in the Hangzhou Bay tidal wetland were investigated. The results showed that there were significant temporal and spatial variations of alkaline phosphatase activity in the intertidal soils. Alkaline phosphatase activity was the highest in July (104.74~38.59 mg·kg^-1·h^-1) and the lowest in February (40.61~8.21 mg·kg^-1·h^-1). Significant differences of alkaline phosphatase activity were detected among four months (p<0.05). The vegetation types also affected alkaline phosphatase activity and significant differences were found between Bare flat and other types (p<0.05). The soil alkaline phosphatase activities for the different vegetation types were as follows: Bare flat (49.50~8.21 mg·kg^-1·h^-1), Phragmites australis (104.63~39.72 mg·kg^-1·h^-1), Spartina abcerniflora (73.23~32.18 mg·kg^-1·h^-1) and Scirpus mariqueter (83.48~9.68 mg·kg^-1·h^-1). Exchangeable phosphorus (Exch-P) content, iron/aluminum bound phosphorus (Fe/Al-P) content and calcium bound phosphorus (Ca-P) content all exhibited the highest value in May and lowest in February, with significant differences (p<0.05). Labile organic phosphorus (L-P) content was the highest in July, followed by May, October and February; moderately labile organic phosphorus (ML-P) content was the highest in February, followed by May, October and July; non-labile organic phosphorus (NL-P) was not significantly different among the four months. The alkaline phosphatase activities were significantly correlated to the numbers of organic phosphate bacteria (r=0.58,p<0.01). It was suggested that number of organic phosphorus bacteria may control alkaline phosphatase activities. Furthermore, soil alkaline phosphatase activities were positively correlated with (Fe/Al) -P (r=0.39, p<0.05), L-P (r=0.37, p<0.05), and NL-P (r=0.31, p<0.05). It was suggested that NL-P may be a potential phosphorus source in the tidal flat wetland.