紫金山次生栎林、马尾松林枯落物与表层土壤的交互作用研究

发布时间：2018-01-01 23:29

本文关键词：紫金山次生栎林、马尾松林枯落物与表层土壤的交互作用研究　出处：《南京林业大学》2016年硕士论文　论文类型：学位论文

【摘要】：枯枝落叶层和土壤层作为森林生态系统的重要层次,具有调节径流、保持水土、涵养水源等重要的生态功能。本文通过对南京紫金山次生栎林、马尾松林的枯落物分解速率及养分释放特征、土壤理化性质及蚯蚓数量的测定分析,研究次生栎林、马尾松林两种不同林分枯落物与表层土壤的交互作用,所得主要结论如下:(1)次生栎林、马尾松林枯枝落叶层质量存在显著性差异,次生栎林枯枝落叶层N、P含量均大于马尾松。并且马尾松枯枝落叶层的C/N、C/P大于次生栎林,差异性极显著(P0.01)。分解1a后马尾松枯落物的干物质失重率小于次生栎林,差异显著(P0.05)。次生栎林、马尾松林枯落物分解都呈现出明显的季节性。(2)分别放置于次生栎林及马尾松林中的次生栎林枯落物,以及分别放置于次生栎林及马尾松林中的马尾松枯落物,经过1a分解后,失重率均具有极显著差异(P0.01),且两种类型的枯落物均在次生栎林中失重率较高,分解速度更快。两种林分枯落物在次生栎林和马尾松林中分解半衰期和95%被分解所需时间,均有极显著差异(P0.01),且均表现为次生栎林林下土壤环境更有利于枯落物的分解。(3)分解1a后,分别放置于次生栎林、马尾松林中的次生栎林枯落物和马尾松枯落物N、P残留率差异显著(P0.05),充分说明次生栎林林下土壤分解环境对枯落物的养分释放有促进作用,表明不同群落类型的林下土壤环境条件对枯落物养分释放有着较为显著的影响。(4)不同林分类型枯落物对土壤容重、毛管孔隙度、最大持水量和毛管持水量有影响。次生栎林中枯枝落叶层下土壤的容重比马尾松低,毛管孔隙度更大,持水性也更好。所以阔叶树种枯枝落叶层较针叶树种更有利于改善土壤结构。(5)不同林分类型枯落物分解及养分释放对土壤养分含量及pH有影响。不同林分枯枝落叶层N含量及分解对土壤全N有显著影响;土壤中P元素在生态系统中流动性较强,并且均于夏季含量达到最大;两种林分枯枝落叶层对土壤全P含量影响不显著(p0.05);次生栎林与马尾松林土壤有效磷与两种林分枯枝落叶层中P的含量变化趋势大致相同,说明枯落物分解对于土壤有效磷含量有影响显著;不同林分枯枝落叶层的分解对土壤速效K浓度影响显著。次生栎林和马尾松林土壤pH值无明显季节性变化,均值分别5.43和4.62,次生栎林呈酸性,马尾松林呈强酸性,次生栎林枯枝落叶层分解有助于升高土壤pH值。(6)枯落物养分含量与土壤养分含量存在一定的相关性。次生栎林、马尾松林枯枝落叶层中N含量与土壤全N均表现为显著相关(P0.05),且次生栎林相关性较强;次生栎林和马尾松林枯枝落叶层中P含量与土壤有效P也表现出显著的相关性(P0.05),且相关程度接近;两种林分枯枝落叶层P含量与土壤全P无明显相关性;次生栎林和马尾松林枯枝落叶层中K与土壤速效K低度相关。(7)不同枯枝落叶层下表层土壤中蚯蚓数量具有较大差异。次生栎林土壤中蚯蚓数量均值为87条/m2,而马尾松林土壤中蚯蚓的数量平均为33条/m2,显著低于次生栎林土壤中蚯蚓的数量,因而枯枝落叶层类型对土壤中蚯蚓数量具有显著影响。
[Abstract]:Litter and soil layer as an important level of forest ecosystem, regulate runoff, soil and water conservation, water conservation and other important ecological functions. This article through to the Nanjing Purple Mountain oak forest, Pinus massoniana forest, litter decomposition rate and nutrient release characteristics, determination of physicochemical properties of soil and earthworm population, research secondary oak forest, pine forest interaction of two kinds of litter and soil, the main conclusions are as follows: (1) secondary oak forest, there are significant differences in litter quality of Pinus massoniana forest, Quercus variabilis forest litter layer N, P content was greater than that of Pinus massoniana and Pinus massoniana. Litter C/N C/P, greater than the secondary oak forest, significant differences (P0.01). After 1A decomposition of Masson Pine litter dry matter weight loss rate is less than the secondary oak forest, significant difference (P0.05). Secondary oak forest, horse tailed forest litter decomposition are presented A significant seasonal. (2) were placed in oak forest and pine forest in secondary oak forest and pine litter, litter were placed in oak forest and pine forest in the fall, after 1A decomposition, the weight loss rate were significant difference (P0.01), and two types of the litter in the secondary oak forest in the weight loss rate is higher, the faster decomposition rate. Two kinds of litter in the secondary oak forest and pine forest in half-life and 95% decomposition time, there were significant difference (P0.01), and showed that the secondary oak forest soil environment more conducive to the decomposition litter decomposition. (3) 1a, were placed in oak forest, Pinus massoniana forest of Quercus variabilis forest litter and Masson Pine litter N, P residues were significant difference (P0.05), shows that the soil under the secondary oak forest litter decomposition environment to dry the nutrient release promoting effect that is not. The soil conditions are the same as the type of community forest has a significant impact on the litter nutrient release. (4) different types of forest litter on soil bulk density, capillary porosity, water holding capacity and capillary moisture effect. Secondary oak forest in the bulk density of soil under Masson Pine litter than low capillary the porosity is larger, the water is better. So the broadleaf litter is conifer more conducive to the improvement of soil structure. (5) different types of forest litter decomposition and nutrient release effects on soil nutrient content and pH. Different forest litter decomposition on soil total content of N and N have a significant impact; the P element in the soil of strong liquidity in the ecosystem, and are in the summer the content reached the maximum; two kinds of forest litter on soil total P content had no significant effect (P0.05); secondary oak forest and pine forest soil available phosphorus and two Changes of the content of forest litter layer in P is roughly the same as that of litter decomposition on soil available phosphorus content had significant effects; effects of different forest litter decomposition on soil available K concentration significantly. The secondary oak forest and pine forest soil pH value had no obvious seasonal variation, respectively 5.43 and 4.62, secondary oak forest is acidic, strongly acidic pine forest, Quercus variabilis forest litter decomposition helps to increase soil pH value. (6) litter nutrient contents and soil nutrient contents have certain correlation. The secondary oak forest, pine forest litter layer of soil total N content and N were significantly correlated (P0.05), and secondary oak forest strong correlation; secondary oak forest and pine forest litter layer and soil available P content in P also showed a significant correlation (P0.05), and the degree of correlation is close to two; forest litter layer and the content of P There was no significant correlation between soil P and soil available K; secondary oak forest and pine forest K in the litter layer is low. (7) the number of earthworms in the surface soil of different litter has great difference. The secondary oak forest soil in the average number of earthworms was 87 /m2, while the number of earthworms in the soil of Pinus massoniana forest an average of 33 /m2, significantly lower than the number of secondary oak forest soil earthworm, and litter type has a significant impact on the number of earthworms.

【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S714

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