中亚热带不同母质发育森林土壤磷组分特征及其影响因素

本研究以福建三明砂岩和花岗岩发育的米槠林土壤和杉木林土壤为对象,分析土壤磷组分、铁铝氧化物、微生物生物量以及磷酸酶活性等指标,研究母质和森林类型对土壤磷组分的影响程度和机制。结果表明: 母质和森林类型显著影响土壤不同磷组分含量。总体上,砂岩发育土壤全磷含量、活性无机/有机磷、中等活性无机/有机磷以及惰性磷含量均显著高于花岗岩发育土壤,并且砂岩发育米槠林土壤活性有机磷含量、中等活性无机/有机磷以及惰性磷含量显著高于砂岩发育杉木林土壤,而花岗岩发育米槠林与杉木林土壤磷组分的含量差异不显著。花岗岩发育的2种森林土壤酸性磷酸酶(ACP)活性显著高于砂岩,而砂岩发育米槠林土壤微生物生物量碳(MBC)和微生物生物量磷(MBP)显著高于砂岩发育杉木林土壤。土壤不同磷组分的含量与土壤不同形态铁铝氧化物含量、MBP、MBC呈显著正相关,而与土壤pH、ACP呈显著负相关,表明土壤母质和森林类型可能主要通过土壤铁铝氧化物赋存形态、ACP、MBP等生物及非生物因子影响中亚热带森林土壤磷组分分配特征。

Characteristics of phosphorus fractions and their driving factors in forest soils with different parent materials in the mid-subtropics,China

With the aim to understand the influence degree and mechanism of parent material and forest type on soil phosphorus component,we analyzed soil P fractions,iron and aluminum oxides,microbial biomass,and phosphatase activity in Castanopsis carlesii and Cunninghamia lanceolata forest soils developed from two types of parent materials,sandstone and granite,in Sanming,Fujian Province.The results showed that both parent material and forest type significantly affected the contents of different P fractions.The contents of total P,labile inorganic/organic P,moderately labile inorganic/organic P,and non-labile P from sandstone-developed soils were significantly higher than those from granite-developed soils.Moreover,soil labile organic P,moderately labile inorganic/organic P and non-labile P fraction in sandstone-developed soils of C.carlesii forest were significantly higher than those of C.lanceolata forest,while the corresponding soil P fractions in granite-deve-loped soils had no significant difference between the two types of forests.The activity of acid phosphatase(ACP)in granite-developed soils was significantly higher than that in sandstone-developed soils under two types of forest,while soil microbial biomass carbon(MBC)and P(MBP)in sandstone-developed soils were significantly higher under C.carlesii forest than under C.lanceolata fo-rest.The content of soil P fractions was significantly positively correlated with the content of different forms of iron and aluminum oxides,MBP,and MBC,but negatively correlated with soil pH and acid phosphatase activity(ACP).Our results indicated that parent material and forest types might affect soil P fractions and characteristics mainly through altering soil iron and aluminum oxides,ACP,MBP in mid-subtropical forest soils.