外源性氮和磷添加对马尾松凋落叶分解及土壤特性的影响

发布时间：2018-05-17 18:26

本文选题：马尾松林 + 凋落叶　；参考：《生态环境学报》2017年10期

【摘要】：研究外源性氮和磷对马尾松(Pinus massoniana)凋落叶分解速率、分解过程中N、P、K含量变化及马尾松林地土壤生化特性的影响,为阐明外源性氮和磷对凋落叶分解土壤养分的影响及为森林养分管理提供科学依据。采用尼龙网袋分解法,在广东马尾松林内建立4块5 m×5 m的小样地,放置凋落叶样品,测定其分解速率和N、P、K含量变化。结果表明,施N对马尾松凋落叶的分解有抑制作用,施P及N+P对凋落物的分解速率有不同程度的促进,其中施P处理的分解最快;分解24个月后,对照,施N、P和N+P的马尾松纯凋落叶分解率分别为90%,74%、98%和97%。施N、P和N+P的马尾松林地凋落叶N含量显著大于凋落叶的初始N含量,分解24个月后各处理凋落叶的N含量分别增加了18%、34%、23%和38%;各处理凋落叶P含量在分解过程中呈现上升的趋势,分解24个月后凋落叶的P含量分别显著增加了27%、21%、163%和144%,P和N+P处理的凋落叶P含量上升幅度大;而凋落叶K含量无明显变化规律。施N和N+P显著增加了土壤的全P和有效P含量,增量分别为4%、14%和23%、222%;加P显著增加土壤了全P、全K和有效P含量,增量分别为18%、6%和277%。施N、施P和施N+P 3种处理显著增加了土壤细菌、真菌和放线菌数量,加P提高了脲酶、磷酸酶及过氧化氢酶活性,增量分别为11%、17%和16%,施N+P提高了磷酸酶和过氧化氢酶活性,增量分别为7%和2%。综上所述,施N抑制马尾松凋落叶的分解,而施P及N+P促进凋落物的分解。在马尾松林施用P肥可以促进凋落叶的分解和养分循环。
[Abstract]:To study the effects of exogenous nitrogen and phosphorus on the decomposition rate of Pinus massoniana leaves, the changes of N ~ (2 +) P ~ (+) K content and the soil biochemical characteristics of Pinus massoniana forest land during the decomposition process of Pinus massoniana (Pinus massoniana). In order to elucidate the effects of exogenous nitrogen and phosphorus on the decomposition of soil nutrients from litter leaves and provide scientific basis for forest nutrient management. Four plots of 5 m 脳 5 m small plots were established in Pinus massoniana forest in Guangdong Province by Nylon net bag decomposition method. The litter leaf samples were placed, and the decomposition rate and the change of N ~ (2 +) P ~ (+) K content were measured. The results showed that application of N could inhibit the decomposition of litter leaves of Pinus massoniana, and P and N P could promote the decomposition rate of litter in varying degrees, among which P application was the fastest, and after 24 months, the control. The decomposition rates of pure litter leaves of Pinus massoniana treated with N P and N P were 98% and 97%, respectively. The N content of litter leaves of Pinus massoniana forest applying N P and N P was significantly higher than the initial N content of litter leaves. After 24 months of decomposition, the N content of litter leaves increased by 18% and 38%, respectively, and the P content of litter leaves increased during decomposition. After 24 months of decomposition, P content in litter leaves increased significantly by 270.21% and 144%, respectively, and the P content of litter leaves increased by 144% and 144%, respectively, but there was no obvious change of K content in littered leaves. Application of N and N P significantly increased the total P and available P contents of the soil, the increments were 414% and 232.22%, respectively, and the total P, the total K and the available P contents of the soil increased significantly with the addition of P, the increments were 18.6% and 277B, respectively. Application of N, P and N P significantly increased the number of bacteria, fungi and actinomycetes, and increased the activities of urease, phosphatase and catalase by 1117% and 16%, respectively. The increments were 7% and 2%, respectively. In conclusion, N application inhibited litter decomposition of Pinus massoniana, while P and N P promoted litter decomposition. The application of P fertilizer in Pinus massoniana forest could promote the decomposition and nutrient cycling of litter leaves.
【作者单位】：华南农业大学林学与风景园林学院;
【基金】：中央财政林业科技推广示范项目(2015-GDTK-07)
【分类号】：S714

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