北方温带森林不同海拔梯度土壤有机质分解酶活性及动力学特征研究

发布时间：2018-01-13 11:34

本文关键词：北方温带森林不同海拔梯度土壤有机质分解酶活性及动力学特征研究　出处：《沈阳农业大学》2016年硕士论文　论文类型：学位论文

【摘要】：本文以老秃顶南坡沿海拔梯度(500-1306 m)不同植被类型下的土壤为研究对象,旨在通过对不同海拔梯度的土壤酶活性、土壤碳矿化速率、土壤酶动力学参数及温度敏感性的研究,并利用相关分析、冗余分析及主成分分析等数学分析方法研究了其与土壤理化性质的关系。探究影响不同海拔梯度土壤酶变化的关键因子以及不同海拔梯度土壤酶对温度升高的响应,揭示未来气候变暖对不同海拔梯度土壤有机质分解的影响,得到如下结论：(1)土壤微生物产生的胞外酶可以降解土壤有机质高分子物质。本研究以北方温带森林老秃顶7个不同海拔梯度的土壤为研究对象,研究不同海拔梯度下土壤水解酶和氧化还原酶活性分布特征以及主要驱动因素。研究结果表明：除N-乙酰-β-氨基葡萄糖苷酶(NAG)之外,α-萄糖苷酶(αG)、p-葡萄糖苷酶(pG)、纤维二糖水解酶(CHB)和木糖苷酶(pX)4种水解酶活性总体上随着海拔的升高而增加,而土壤氧化还原酶活性并没有表现出随海拔梯度变化的规律。5种水解酶活性与有机碳(SOC)和颗粒有机碳(POC)含量呈显著正相关(p0.05),与可溶性有机碳(DOC)含量呈极显著正相关(p0.01)；除NAG以外,其它4种水解酶都与含水量(SWC)、全氮(TN)含量呈极显著正相关；土壤过氧化物酶(PER)活性与SOC、TN和SWC含量呈极显著正相关,与POC显著正相关；多酚氧化酶(PPO)只与土壤pH显著正相关。这表明土壤水解酶活性与土壤有机质的含量密切相关。(2)酶动力学可以完整的描述酶催化反应进程,酶动力学参数温度敏感性可以反映其对温度变化及未来气候变暖情况下的响应。本研究选择北方温带森林老秃顶南坡3个不同海拔梯度,即1233 m(岳桦林)、1060 m(针阔混交林)、825 m(红松林)森林土壤,进行室内不同温度梯度培养试验,研究土壤碳矿化速率和土壤pG动力学参数及温度敏感性。结果表明：温度升高加快了不同海拔梯度土壤碳矿化速率(Cmin),且1233 m(岳桦林)处Cmin最高,海拔梯度和温度对Cmin均有显著影响(p0.001)碳矿化速率温度敏感性CQ1O (Cmin))为1233 m(岳桦林)825 m(红松林)1060 m(针阔混交林),但差异不显著(p0.05)。土壤βG动力学参数最大反应速率(Vmax)和米氏常数(Km)均随着培养温度的升高而增加,Vmax的温度敏感性(Q10(Vmax))变化范围为1.78-1.90；Km的温度敏感性(Q10(Km))变化范围为1.79-2.0。1233 m(岳桦林)处Q10(Vmax)/Q10(Km)最高,显著高于825 m(红松林)和1060 m(针阔混交林),意味着高海拔岳桦林土壤有机质碳分解受温度升高影响最大。
[Abstract]:In this paper, the soil from 500-1306 m) on the south slope of old balding was studied under different vegetation types. The purpose of this study was to study the soil carbon mineralization rate through the soil enzyme activity of different elevation gradients. The kinetic parameters and temperature sensitivity of soil enzyme were studied, and the correlation analysis was used. The relationship between soil physical and chemical properties and soil physical and chemical properties was studied by means of redundancy analysis and principal component analysis. The key factors affecting soil enzyme changes at different elevations and the response of soil enzymes at different elevations to temperature rise were explored. Should. The effects of future climate warming on the decomposition of soil organic matter at different altitude gradient were revealed. Conclusion: (1) extracellular enzymes produced by soil microbes can degrade soil organic matter macromolecules. In this study, 7 soils with different elevation gradients in temperate forest in North China were studied. The distribution characteristics and main driving factors of soil hydrolase and redox enzyme activities at different elevation gradients were studied. The results showed that: except for N-acetyl- 尾 -glucosaminidase (NAG). The activities of 伪 -glucosidase (伪 -glucosidase) (伪 -glucosidase), cellulose hydrolase (CHB) and xylosidase (PX) increased with the increase of altitude. However, the activity of soil oxidoreductase did not show a significant positive correlation with the content of organic carbon (SOC) and particulate organic carbon (POC). There was a significant positive correlation with the content of soluble organic carbon (DOC). With the exception of NAG, the other four hydrolases were positively correlated with the contents of water content and total nitrogen. The activity of soil peroxidase peroxidase (per) was positively correlated with the contents of TN and SWC, and with POC. PPO was only positively correlated with soil pH, which indicated that soil hydrolase activity was closely related to the content of soil organic matter. The temperature sensitivity of enzyme kinetic parameters can reflect its response to temperature change and future climate warming. In this study, three different elevation gradients were selected for the southern slope of the old balding forest in the northern temperate zone. That is 1233m (Yuehuan forest) 1060m (coniferous and broad-leaved mixed forest) forest soil (Pinus koraiensis forest), the indoor temperature gradient culture experiment was carried out. The soil carbon mineralization rate, soil PG kinetic parameters and temperature sensitivity were studied. The results showed that the increase of temperature accelerated the soil carbon mineralization rate at different elevations. The Cmin was the highest at 1233m (birch forest). Elevation gradient and temperature had significant effects on Cmin (p0.001). The temperature sensitivity of CQ1O was 1233m (Pinus koraiensis forest) (Pinus koraiensis forest). 1060m (coniferous and broad-leaved mixed forest). But the difference was not significant (p0.05). The maximum reaction rate (Vmax.) and the Michlet constant (Km) of soil 尾 -G kinetic parameters increased with the increase of culture temperature. The temperature sensitivity of Vmax was 1.78-1.90. The range of temperature sensitivity of km is 1.79-2.0.1233 m (birch forest). Significantly higher than 825m (Pinus koraiensis) and 1060m (coniferous and broad-leaved mixed forest) means that soil organic matter carbon decomposition in high altitude birch forest is most affected by temperature rise.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S714

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