土壤微生物生物量和酶活性对林窗尺度的响应

发布时间：2018-05-04 23:29

本文选题：林窗尺度 + 侧柏人工林　；参考：《南京林业大学》2015年硕士论文

【摘要】：本研究以徐州侧柏(Platycladus orientalis(L.)Franco)人工林3种不同尺度(S林窗:半径为4m、M林窗:半径为8m、L林窗:半径为12m)林窗及对照样地(未开设林窗)为对象,研究了林下植被多样性在林窗内外,土壤理化性质、土壤微生物生物量及酶活性在林窗内、林缘及林窗外部对不同尺度林窗的响应,主要结果如下:(1)林窗内无论灌木层还是草本层的Margalef指数均大于对照样地。林窗内灌木层的Simpson指数和Shannon指数大于对照样地;草本层的Simpson指数和Shannon指数最大值均出现于S林窗,L林窗和M林窗均低于对照样地。灌木层的pielou均匀度指数最大值出现在S林窗,L林窗和M林窗均低于对照样地;草本层的pielou均匀度指数最大值出现于对照样地,并随林窗尺度增大而降低。(2)与对照地相比,林窗影响了土壤温度、含水量及可溶性有机碳(DOC)含量,不同林窗影响程度不同。其中,S林窗对土壤理化性质的影响最为明显。(3)与对照样地相比,M林窗显著提高了春季土壤微生物生物量碳(MBC)含量(p0.05),M林窗和S林窗在春季时对土壤MBC含量的生态场效应达到林窗外部位置。土壤MBC含量与土壤全碳和DOC含量呈极显著正相关(p0.01),与pH值呈显著负相关(p0.05),与土壤温度呈极显著负相关(p0.01)。S林窗显著降低了春季土壤微生物生物量氮(MBN)含量(p0.05),而M林窗显著提高了夏季土壤MBN含量(p0.05)。L林窗在春季和夏季时对土壤MBN含量的生态场效应达到林窗外部位置,M林窗在冬季时对土壤MBN含量的生态场效应达到林缘位置,S林窗在冬季时对土壤MBN含量的生态场效应达到林缘位置,在春季时达到林窗外部位置。土壤MBN含量与土壤含水量、DOC含量和MBC含量呈极显著正相关(p0.01),与土壤全碳呈显著正相关(p0.05)。(4)与对照地相比,林窗尺度对4种土壤酶活性均有显著影响。M林窗在冬季和春季对土壤过氧化物酶活性的生态场效应达到林窗外部位置;S林窗在秋季时达到林窗外部位置。L林窗在春季时对土壤脱氢酶活性的生态场效应达到林窗外部位置;M林窗在冬季和夏季时达到林窗外部位置;S林窗在秋季和春季时达到林窗外部位置。L林窗在秋季和夏季时对土壤脲酶活性的生态场效应达到林窗外部位置;M林窗在春季时达到林窗外部位置;S林窗在秋季和夏季时达到林窗外部位置。L林窗在春季和夏季时对土壤蔗糖酶活性的生态场效应达到林窗外部位置;M林窗在夏季时达到林窗外部位置;S林窗在夏季时达到林窗外部位置。(5)本研究中不同尺度林窗对其中植被多样性、土壤理化性质、土壤微生物量和酶活性均有不同程度的影响,即不同尺度林窗的场效应不同,表明不同尺度林窗的形成对土壤养分循环的影响范围不同。本研究可为生产实践中制定合理的林窗大小及找到加快森林系统更新的有效途径提供科学依据。
[Abstract]:In this study, 3 different scales of Xuzhou Platycladus orientalis (Platycladus orientalis (L.) Franco) plantation (S forest window: radius 4m, M window: radius 8m, L forest window: radius 12m) forest window and control sample (no opening window) were used to study the soil physical and chemical properties, soil microbial biomass and enzyme activity of the vegetation diversity under forest windows. The main results are as follows: (1) the Margalef index of shrubs and herbaceous layers in the forest window is greater than that of the control. The Simpson index and the Shannon index of the shrub layer in the forest window are larger than the control, and the Simpson index and the maximum Shannon index of the herb layer are all in the S forest. The window, L window and M window were lower than the control. The maximum Pielou evenness index of the shrub layer appeared in the S forest window, the L window and the M window were lower than the control. The maximum value of the Pielou evenness index of the herb layer appeared in the control sample, and decreased with the increase of the forest window scale. (2) the forest window influenced the soil temperature and water content compared with the control area. The content of soluble organic carbon (DOC) and the influence degree of different forest windows were different. Among them, the influence of S window on soil physical and chemical properties was the most obvious. (3) compared with the control sample, the M forest window significantly improved the soil microbial biomass carbon (MBC) content (P0.05) in spring, and the ecological effect of M forest window and S forest window on soil MBC content reached the forest window in spring. There was a significant positive correlation between soil MBC content and total soil carbon and DOC content (P0.01), a significant negative correlation with the value of pH (P0.05), and a significant negative correlation with soil temperature (P0.01).S forest window significantly reduced the soil microbial biomass nitrogen (MBN) content (P0.05) in spring soil, while M forest window significantly increased the MBN content of the soil in summer (P0.05) window. The ecological field effect of soil MBN content reached the outside position of the forest window in spring and summer. The ecological field effect of the M forest window on the soil MBN content reached the forest edge position in winter. The ecological field effect of the S forest window on the soil MBN content reached the forest edge position in winter, and reached the outside position of the forest window in spring. The content of soil MBN and the soil water content were water. There was a significant positive correlation between the content of DOC and the content of MBC (P0.01), and a significant positive correlation with total soil carbon (P0.05). (4) compared with the control area, the forest window scale significantly affected the activity of the 4 kinds of soil enzymes in the.M window to reach the outside of the forest window in winter and spring, and the S forest window reached the forest window in the autumn. The ecologic effect of.L forest windows on the activity of soil dehydrogenase in spring reached the outside position of the forest window, and the window of M forest reached the outside window position in winter and summer, and the S forest window reached the outside position of the forest window in autumn and spring, and the ecological effect of.L forest window on the soil urease activity reached the outside of the forest window in autumn and summer; M In spring and summer, the S forest window reached the outside position of the forest window in the autumn and summer. The ecological effect of the.L forest window on the activity of invertase in the spring and summer reached the outside position of the forest window in spring and summer; the window of the M forest reached the outside window of the forest window in summer; the S forest window was in summer Ji Shida to the outside window of the forest. (5) this study did not. The same scale forest windows have different effects on the vegetation diversity, soil physical and chemical properties, soil microbial biomass and enzyme activity, that is, the field effect of different scale forest windows is different, which indicates that the influence range of different scale forest windows on soil nutrient cycling is different. This study can make reasonable forest window size and find out in production practice. To provide scientific basis for accelerating the regeneration of forest system.

【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S714.3

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