海南岛滨海木麻黄林凋落物分解及土壤养分动态

Litter Decomposition and Dynamics of Soil Nutrients in Casuarina equisetifolia Plantation on the Coast of Hainan Island

通过对海口市桂林洋海岸木麻黄(Casuarina equisetifolia)防护林地表的凋落物进行持续清除处理,与保留凋落物层的对照样地进行比较试验,研究防护林凋落物层的存在与否对土壤养分、木麻黄凋落物的分解速率、凋落物中不同养分元素在分解过程中的释放量的影响,为提高木麻黄林的土壤肥力与持续经营提供科学依据。结果表明:(1)在两种样地中,凋落物的分解速率处理样地[0.402 g/(g.a)]低于对照样地[0.548 g/(g.a)]。经过18个月的分解,N、P、K 3种元素的释放率均为处理样地小于对照样地,说明样地中凋落物层的清除对凋落物的分解与元素的释放有一定的减缓作用。(2)处理样地土壤N、P含量的变化较对照样地更平缓,说明在无新鲜凋落物输入的情况下,土壤腐殖层仍然进行着矿质化过程,进行着养分的分解和积累,但不如有凋落物输入时明显。

Effects of removal of litter layer on the litter decomposition rate,release of nutrient elements during the decomposition process and the dynamics of soil nutrients were studied by comparing treatment(litter removed) and control(litter preserved) sites on the coast of Guilinyang,Haikou city to provide a scientific basis for improving the soil fertility of Casuarina equisetifolia plantation as windbreak.The results were as follows.(1) The litter decomposition rate in the treatment site [0.402 g/(g·a)] was less than that in the control site [0.548 g/(g·a)].During 18 months of decomposition,the percentage of release of N、P and K in the treatment site were lower than that in the control site.It was indicated that clearing litter could slow down the decomposition and release of elements.(2) Changes of N and P content in the treatment site were more subdued than that in the control site.It was indicated that the soil was also in the mineralization process,such as decomposition and accumulation on nutrients,even there was no fresh litter in the treatment site.But the mineralization process was less significant in the treatment site than in the control site.