马尾松两种林型土壤养分特征及其与凋落物质量的关系

【目的】研究土壤养分和地被层凋落物养分含量的差异,为马尾松人工林营林措施及地力维持提供科学依据。【方法】以鼎湖山两种典型林型(马尾松纯林和马尾松-黧蒴混交林)为研究对象,对比分析0~60 cm土层的土壤养分含量及地被层凋落物养分含量的差异,探索凋落物质量如何影响土壤养分。【结果】1)林型对土壤有机质、全氮和硫酸根含量有显著影响(P<0.05),对土壤全磷、交换性K+、Ca2+和Mg2+有极显著影响(P<0.01),混交林土壤养分含量(除硝态氮含量和交换性H+含量以外)均高于纯林。2)相同林型不同土层间土壤养分含量差异极显著(P<0.01),其中,土壤有机质和全氮含量随土层的加深而递减,且主要聚集在0~10 cm土层,表聚效应十分明显。3)纯林凋落物有机碳、全氮、C/N和全磷等含量高于混交林;相同林型不同分解层凋落物有机碳、全钙和全镁含量有显著差异(P<0.05),均表现为未分解层>半分解层>腐殖质层。4)土壤养分与地被层凋落物质量的RDA分析表明,0~10 cm土层土壤养分与腐殖质层有机碳呈极显著负相关(P<0.01),与腐殖质层C/N呈显著负相关(P<0.05);在10~20 cm土层,土壤养分与腐殖质层有机碳呈极显著负相关(P<0.05)。【结论】纯林的土壤养分低于混交林的主要原因是纯林凋落物具有较高的C/N和有机碳含量。

Study on the soil nutrient characteristics and their relationship with litter quality in two forest types of Pinus massoniana

【Objective】Studying the differences in soil nutrient and ground cover litter nutrient content can provide a scientific basis for the forestry measures and soil fertility maintenance of Pinus massoniana plantations.【Method】Taking two typical forest types(Pinus massoniana and mixed forest of Pinus massoniana and Castanopsis fissa)in Dinghushan as the research object,the differences of soil nutrient content and litter nutrient content in 0-60 cm soil were compared and analyzed,and how the litter quality was affected soil nutrients.【Result】1)Forest type has significant effect on soil organic matter,total nitrogen and sulfate content(P<0.05),and on soil total phosphorus,exchangeable K+,Ca2+and Mg2+(P<0.01),the soil nutrient content of mixed forest(except nitrate nitrogen and exchangeable H+content)is higher than that of pure forest.2)The difference of soil nutrient content between different soil layers of the same forest type is very significant(P<0.01),among which,the content of soil organic matter and total nitrogen decrease with the deepening of soil layer,and mainly concentrated in the 0-10 cm soil layer,the surface accumulation effect is very obvious.3)The content of organic carbon,total nitrogen,C/N and total phosphorus in pure forest litter are higher than that in mixed forests;there are significant differences in litter organic carbon,total calcium and total magnesium in different decomposition layers(P<0.05),all appear as fresh litter>fragmented litter>humified and amorphous litter.4)RDA analysis of soil nutrients and litter quality of ground cover show that,soil nutrients in 0-10 cm soil layer are significantly negatively correlated with organic carbon in humified and amorphous litter(P<0.01),and negatively correlated with C/N in humified and amorphous litter(P<0.05);in 10-20 cm soil layer soil nutrients are significantly negatively correlated with organic carbon in humified and amorphous litter(P<0.05).【Conclusion】The main reason for the low soil nutrient content of pure forests is that the pure forest litter has higher C/N and organic carbon content.