陕西省森林生态系统生态化学计量特征

发布时间：2019-07-06 17:34

【摘要】：为了阐明陕西省森林生态系统植物与土壤之间的养分循环关系,明确叶片与乔木层整体生态化学计量特征是否有一致性,本文选取陕西省森林生态系统121个具有代表性的样点为研究对象,采用野外调查与室内分析相结合的方法进行研究,对其不同乔木器官和土壤C、N、P含量进行了测定,分析了其叶片、乔木层(叶、枝、干、根)和土壤层(0-100 cm)化学计量特征及之间的关系,以及乔木层和土壤层C、N、P含量及其化学计量特征与地理因子及气候因子的关系。同时,对不同区域(陕北地区、关中地区、陕南地区)的人工林和自然林生态系统乔木层与土壤层C、N、P含量及其化学计量特征的异同进行分析。另外,对陕西省不同科(豆科植物刺槐、壳斗科植物辽东栎以及松科植物油松)及不同栎类(辽东栎、栓皮栎、麻栎)树种的乔木层与土壤层C、N、P含量及其化学计量特征的差异以及其与地理因子和气候因子的异同进行分析研究。本研究可以为陕西省人工林的建设和管理提供理论依据,丰富西北地区乃至全国的C、N、P化学计量特征数据库。研究结果表明:1)陕西省森林生态系统乔木层的C、N、P含量分别为452.23、4.91、0.49 mg·g-1,而植物营养器官叶片的C、N、P含量分别为466.28、16.72、1.30 mg·g-1,表现为乔木层养分含量显著低于叶片水平,且叶片N、P含量较缺乏;土壤层(0-100cm)的C、N、P含量分别为7.65、0.74、0.53 mg·g-1,表层土壤(0-10cm)的C、N、P含量分别为21.73、1.80、0.56 mg·g-1,土壤层各养分含量均表现出表层富集现象,且土壤层养分较匮乏且处于低水平平衡状态。2)陕西省森林生态系统的叶片、乔木层与土壤间的关系是不同的;乔木层C含量与年均降雨呈显著的相关关系,说明降雨是影响陕西省植物生长状态的一个主要因素。3)就不同区域而言,陕南地区的植物光合作用固定C的能力较陕北地区和关中地区强,乔木层C含量较高;关中地区土壤较为肥沃,土壤层N、P含量较高。4)对于人工林生态系统来说陕北地区有机质分解较快,且土壤层P的有效性较高,对于自然林生态系统来说虽然不同区域有机质分解速率是一致的,但是陕北地区土壤层P的有效性也是较高的。5)对于人工林生态系统,陕北地区侧柏对N、P的利用效率较高且有着更高的有机质分解速率,关中地区油松对N、P的利用效率最高,刺槐有机质分解速度最高,陕南地区则是马尾松对于N、P的利用率较高,华山松有机质分解速率较高;对于自然林生态系统,陕北地区植物对P的利用效率高低依次为麻栎、辽东栎、白桦,白桦有着更高的有机质分解速率,关中地区栓皮栎对N的利用效率较高,同时栓皮栎和辽东栎的有机质分解速率较高,陕南地区麻栎对P的利用率是最高的,有机质分解速率则是一致的。6)不同科树种在单位N、P养分条件下,油松有较高的养分利用效率,但是刺槐的生长较快。同时,刺槐林生态系统的有机质分解速度较快,而油松林生态系统的N、P有效性和累积效率较高。7)栎类不同树种中,辽东栎林生态系统植物的N、P养分利用效率较低,各栎类树种的生长速率基本一致,有机质分解速率也是一致的,但是栓皮栎的P有效性和累积效率要高于辽东栎。8)不同科树种中只有油松对N、P元素的吸收具有一定的比例关系,而栎类不同树种中则是辽东栎对N、P元素的吸收具有一定的比例关系。9)不同树种乔木层与土壤层C、N、P含量及其化学计量特征与地理及气候因子的关系不尽相同,但是也存在一致的地方:就不同科树种而言,除油松外,各树种乔木层C含量均与年均降雨呈显著的相关性;乔木层N、P含量及其N:P值除辽东栎外,均与纬度无显著性的相关关系;土壤层C与年均降雨无论是对不同科的树种的还是同一属的3种树种都不存在显著的相关关系,但是除刺槐与栓皮栎外,其他各树种土壤层C含量与年均温度均存在不同程度的相关关系;土壤层N含量除油松外,与年均降水、年均温度均没有显著性相关关系。
文内图片：

图片说明：陕西省森林样点分布图
[Abstract]:In order to clarify the relationship between the nutrient cycling between the plant and the soil of the forest ecosystem in Shaanxi Province, it is clear whether the characteristics of the overall ecological chemical measurement of the leaf and the tree layer are consistent, and the representative samples of the forest ecosystem in Shaanxi Province are selected as the research object. The method of field investigation and indoor analysis was used to study the contents of C, N and P in different arbor organs and soil, and the chemical measurement features and the relationship between the leaf, tree layer (leaf, branch, stem, root) and soil layer (0-100 cm) were analyzed. And the relationship between the content of the tree layer and the soil layer C, N, P and the chemical measurement characteristics of the tree layer and the soil layer and the geographic factors and the climatic factors. At the same time, the similarities and differences of the tree layer and the soil layer C, N, P content and their chemical measurement characteristics of the artificial forest and the natural forest ecosystem in different regions (northern Shaanxi, Guanzhong and southern Shaanxi) were analyzed. In addition, the tree layer and soil layer C and N of different species of Shaanxi (Leguminosae), Robinia pseudoacacia, Quercus liaotungensis, and pine (Pinus tabulaeformis) and Quercus variabilis (Quercus liaotungensis, Quercus variabilis, and Quercus acuminata) and the soil layers C, N, The difference of P content and its chemical measurement features and its similarity to geographic factors and climatic factors are analyzed and studied. The study can provide a theoretical basis for the construction and management of the plantation in Shaanxi Province, and enrich the C, N and P chemical measurement feature database in the northwest and even the whole country. The results showed that:1) The contents of C, N and P in the tree layer of the forest ecosystem in Shaanxi province were 452.23, 4.91 and 0.49 mg 路 g-1, respectively, while the contents of C, N and P in the vegetative organs of the plant were 466.28, 16.72 and 1.30 mg 路 g-1, respectively. The content of C, N and P of soil layer (0-100 cm) was 7.65, 0.74, 0.53 mg 路 g-1 respectively, and the content of C, N and P in surface soil (0-10 cm) was 21.73, 1.80, 0.56 mg 路 g-1, respectively. and the soil layer nutrient is scarce and is in a low-level equilibrium state.2) the relationship between the leaves of the forest ecosystem in the Shaanxi province, the tree layer and the soil is different, the content of the tree layer C and the average annual rainfall show a significant correlation, It is indicated that rainfall is one of the main factors that affect the growth state of the plant in Shaanxi Province.3) In the case of different regions, the ability of plant photosynthesis to fix C in the south of Shaanxi is stronger than that in the northern and central regions, and the content of the tree layer C is higher; the soil in the Guanzhong area is more fertile, and the soil layer N, P content is higher.4) For the artificial forest ecosystem, the organic matter decomposition of the northern part of the northern Shaanxi is fast, and the soil layer P is more effective, and for the natural forest ecosystem, although the decomposition rate of the organic matter in different regions is consistent, However, the efficiency of soil layer P in northern Shaanxi is also higher.5) For the artificial forest ecosystem, the utilization efficiency of the Platycladus orientalis in the northern Shaanxi is higher and the decomposition rate of the organic matter is higher, and the utilization efficiency of the Chinese pine in the Guanzhong area is the highest for the N and P. The decomposition rate of the organic matter of the Robinia pseudoacacia is the highest, the utilization ratio of the Pinus massoniana to the N and the P is higher, and the decomposition rate of the organic matter of the Chinese mountain pine is higher; for the natural forest ecosystem, the utilization efficiency of the plant to the P in the northern part of the northern Shaanxi is in the order of the Quercus, the Quercus liaotungensis and the Betula platyphylla, Betula platyphylla has a higher decomposition rate of organic matter, and the utilization efficiency of Quercus variabilis in Guanzhong area is higher, and the organic matter decomposition rate of Quercus variabilis and Quercus liaotungensis is higher, and the utilization rate of Quercus in the southern part of Shaanxi is the highest. The decomposition rate of organic matter is the same.6) Under the condition of N and P, Chinese pine has higher nutrient use efficiency, but the growth of Robinia pseudoacacia is fast. At the same time, the organic matter decomposition rate of the Robinia pseudoacacia forest ecosystem is fast, while the N, P and accumulation efficiency of the oil-forest ecosystem are higher. The growth rate of the tree species is basically the same, and the decomposition rate of the organic matter is also consistent, but the P-effectiveness and the accumulation efficiency of the Quercus variabilis are higher than that of the Quercus liaotungensis. The different species of Quercus liaotungensis have a certain proportion to the absorption of N and P elements in different species of Quercus liaotungensis. In the case of different species of tree species, the content of tree layer C of each tree species was significantly correlated with the average annual rainfall except for Pinus tabulaeformis, and the content of N, P and N: P in the arbor layer were not significantly correlated with the latitude except for Quercus liaotungensis. There was no significant correlation between the soil layer C and the average annual rainfall, either for the tree species of the different family or the same genus, but the soil layer C content and the average annual temperature of the other tree species were related to the average annual temperature except the Robinia pseudoacacia and the Quercus variabilis. The N content of soil layer was not related to the average annual precipitation and the average annual temperature except Pinus tabulaeformis.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S718.5

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