林冠损伤对南岭常绿阔叶林土壤ABA库的影响

发布时间：2018-06-03 21:20

本文选题：林冠损伤模拟 + 林下土壤　；参考：《中南林业科技大学》2015年硕士论文

【摘要】：脱落酸(ABA)是植物体合成的一种植物激素,对植物生长的多个方面具有重要调节作用。植物体合成的内源ABA通过凋落物、穿透雨、树干流、根系分泌等方式进入森林群落形成外源ABA,并通过微生物、光照、地表径流等方式分解或输出从而在土壤中达到动态平衡。林冠损伤后森林群落结构发生改变,而土壤ABA影响种子的萌芽和森林群落的演替,森林林冠受损后土壤ABA浓度如果降低则能解除对先锋种的抑制作用,使受损森林结构中先锋种所占比例上升而发生一定程度的逆向演替,而监测森林群落中ABA动态输入输出对研究森林结构改变机理会有更好的认识,也对生态理论,森林演替过程研究具有重要意义。本文在2008年中国南方特大冰雪灾害背景下,在南岭小坑地区选取未受到2008年冰雪灾害的常绿阔叶林,通过人工去除林冠层模拟冰灾对林冠的损伤并通过添加和移除新鲜枝叶方式研究冰雪灾害和“非正常凋落物”对外源ABA输入输出和现存量的影响。样品中的ABA含量使用酶联免疫法(ELISA)测定,并计算不同处理样地的凋落物、穿透雨、树干流ABA输入量,地表径流ABA输出量,以及分析林下土壤ABA含量和土壤微生物对ABA的分解特征。通过对比不同处理样地间的ABA输入输出量,揭示林冠受损对土壤ABA库的影响。本论文获得的主要结论如下：(1)林冠受损样地凋落物的输入量在4月和7月低于未受损样地,1月和10月和未受损样地持平,年均输入量约为未受损样地的75%；同时林冠受损样地凋落物中ABA含量也不同程度低于未受损样地。林冠受损样地通过凋落物输入ABA总量低于未受损样地,年平均输入量约为未受损样地的56%。“非正常”凋落物的添加和移除对正常凋落物输入量和凋落物ABA含量均无明显影响。(2)林冠受损后,样地穿透雨量略高于未受损样地,但差别不明显,树干流和地表径流均明显低于未受损样地。林冠受损样地穿透雨、树干流和地表径流中的ABA含量在5-8月低于而在9-11月高于未受损样地。ABA通过穿透雨和树干流的输入量和通过地表径流的输出量主要受降雨量影响。(3)对比凋落物、穿透雨和树干流ABA输入量可知：未受损样地中凋落物ABA输入量占这三种ABA输入量的30%左右,穿透雨占48%左右,树干流占22%左右。林冠受损样地样地凋落物ABA输入量占这三种ABA输入量的23%左右,穿透雨占61%左右,树干流占16%左右。雨水的淋溶是ABA进入土壤的重要途径。(4)实验地林下土壤ABA含量在100ng·g-1干土左右,符合演替中前期阶段的林下土壤ABA含量。各月份林下土壤中ABA含量依次为10月1月4月7月。各不同处理样地间土壤ABA含量在各月份间均无明显差异。(5)在室内培养条件下,土壤微生物能够在数天内快速分解掉部分(16.1～45.8%)土壤ABA,之后土壤ABA表现为缓慢的线性分解过程,分解速率为0.24%·d-1。高ABA含量土壤中ABA分解速率前期阶段高于而后期阶段低于低ABA含量土壤。土壤微生物具有一定防止土壤ABA含量过低的作用。
[Abstract]:Abscisic acid (ABA) is a plant hormone synthesized by plant body, which plays an important regulatory role in many aspects of plant growth. The endogenous ABA synthesized by plant body enters forest communities through litter, rain, tree stem and root secretion to form exogenous ABA and decomposes or output through microbiology, light, surface runoff and so on. The forest community structure changes after the crown damage, and the soil ABA affects the germination of the seed and the succession of the forest community. The decrease of the soil ABA concentration after the damage of the forest canopy can relieve the inhibitory effect on the pioneer species, which makes the proportion of the first front species in the damaged forest structure rising to a certain extent. In succession, monitoring the dynamic input and output of ABA in forest community will have a better understanding of the study of the mechanism of forest structure change, and it is of great significance to the study of ecological theory and forest succession process. Under the background of the catastrophic ice and snow disaster in southern China in 2008, this paper selects evergreen broad-leaved in the small pit area of Nanling in the small pit area of Nanling, which has not been affected by the snow and snow disaster in 2008. The effects of ice and snow disaster and "abnormal litter" on the input and output of exogenous ABA were studied by adding and removing fresh branches and leaves by artificial removal of canopy layer by artificial removal of canopy layer. The ABA content in the sample was measured by enzyme-linked immunosorbent assay (ELISA), and the litters of different processing plots were calculated and the rain was penetrated. The ABA input of the trunk stream, the ABA output of the surface runoff, and the analysis of the soil ABA content under the forest and the decomposition characteristics of the soil microorganism to the ABA. By comparing the ABA input and output of different processing plots, the influence of the damage of the canopy to the ABA Bank of the soil was revealed. The main conclusions obtained in this paper are as follows: (1) the input of the damaged litter in the crown of the forest canopy The volume was lower in April and July than in undamaged samples, in January and October and in undamaged samples. The annual input amount was about 75% of the undamaged sample, and the ABA content in the litters of the damaged canopy of the forest canopy was also lower than that of the undamaged land. The total amount of ABA in the damaged canopy of the canopy was lower than that of the undamaged land, and the annual average input was about The addition and removal of 56%. "abnormal" litter in the undamaged area had no obvious effect on the input and ABA content of the normal litter. (2) after the crown was damaged, the rainfall was slightly higher than that of the undamaged sample, but the difference was not obvious. The tree trunk and surface runoff were obviously lower than that of the undamaged land. The ABA content in the dry and surface runoff was lower in 5-8 months than in 9-11 months higher than that of the undamaged sample land.ABA through the input of the rain and the tree trunk and the output of the surface runoff. (3) compared to the litter, the penetration rain and the ABA input of the tree trunk stream showed that the ABA input of the litter in the undamaged plots accounted for the three A. About 30% of the input of BA, the penetration rain accounts for about 48%, and the trunk flow accounts for about 22%. The ABA input of the ground like ground like ground litter of the damaged canopy accounts for about 23% of the three ABA inputs, the penetration rain accounts for about 61%, the trunk flow is 16%. The leaching of the rain is an important way for ABA to enter the soil. (4) the ABA content of the soil under the experimental ground and forest is in the left 100ng g-1 dry soil The content of ABA in the soil under the early stage of succession was in line with the content of ABA in the soil under the forest in the month of October and July April. There was no significant difference in the content of soil ABA between different treatments. (5) under the conditions of indoor culture, soil microbes could quickly decompose some (16.1 to 45.8%) soil ABA within a few days. The soil ABA showed a slow linear decomposition process, and the decomposition rate was 0.24%. D-1. high ABA content in the soil. The early stage of ABA decomposition rate was higher than that in the late stage, while the later stage was lower than the low ABA content soil. Soil microbes had a certain effect on preventing the low ABA content in soil.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S714

【共引文献】