本文選題：水解酶活性 + 氮沉降�。� 參考：《東北師范大學》2015年碩士論文

【摘要】：土壤水解酶可以通過催化作用加速陸地生態(tài)系統(tǒng)土壤中有機質的降解過程,釋放出可以直接被植物和微生物等有機體吸收和利用的營養(yǎng)元素。全球變化能直接或間接影響草地土壤酶活性并進而影響草地生態(tài)系統(tǒng)的能量流動和物質循環(huán)。本研究以我國內蒙古東部的貝加爾針茅草甸草原為對象,研究草原土壤水解酶活性對兩種全球變化——氮沉降和降水量增加的響應。實驗樣地建立于2010年,采用施氮(N0:0 g N/m2a、N1:5 g N/m2a和N2:10 g N/m2a)和增雨(W0:自然降水、W1:增加1/7自然降水和W2:增加2/7自然降水)二因素、三水平交互設計。于2014年5月、7月、8月和9月取土樣(0-15cm)測定了7種土壤水解酶活性,即α葡糖苷酶(αG)、β葡糖苷酶(βG)、β木糖苷酶(βX)、纖維二糖水解酶(CBH)、乙酰氨基葡萄糖苷酶(NAG)、L-亮氨酸氨基肽酶(LAP)和酸性磷酸酶(a P),以及土壤理化性質、植物群落地上生物量和土壤微生物量碳。擬回答以下科學問題:1)植物生長高峰期,不同梯度的增氮、增雨及二者交互作用會對土壤水解酶活性產生怎樣的影響?2)增氮、增雨及二者交互作用會對土壤水解酶活性的季節(jié)動態(tài)變化產生怎樣的影響?3)在增氮增雨處理下,影響土壤水解酶活性變化的主要環(huán)境因子是什么?得出以下主要結論:(1)低濃度(5g N/m2a)的增氮處理顯著提高了植物生長高峰期土壤水解酶的活性,但是隨著增氮梯度的增加,這種促進作用被減弱了。在植物生長高峰期低水平的增雨處理(1/7自然降水)提升了βG、LAP和a P的活性,而在高水平增雨(2/7自然降水)處理下,αG、βG、NAG、LAP和a P的活性受到抑制。(2)在植物生長高峰期,增氮與增雨對αG、βG、NAG、LAP和a P的活性都有顯著交互作用。但是增雨處理在一定程度上抵消了增氮處理對土壤水解酶活性的促進作用。(3)增氮處理在一定程度上提高了不同季節(jié)土壤水解酶的活性,但并沒有改變大多數(shù)土壤水解酶的季節(jié)動態(tài)規(guī)律。而增雨處理在不同程度上抑制了不同季節(jié)土壤水解酶的活性,并且降低了不同季節(jié)水解酶活性的變異幅度。(4)在增氮、增雨及二者交互處理下,導致土壤水解酶活性變化的主要因子是土壤中的氮和磷等非生物因素,而植物和微生物等生物因素的作用并不明顯。(5)增氮處理對土壤水解酶活性的作用存在一定的閾值,即適度增氮能促進酶活性,而增氮量超過閾值時則表現(xiàn)為抑制效應。而降雨量變化對土壤水解酶的調控作用很大程度上受土壤原有水分狀態(tài)和當年總降雨量的影響。本實驗通過研究貝加爾針茅草甸草原土壤水解酶活性對不同梯度增氮增雨的響應,以及增氮增雨處理對土壤水解酶活性的季節(jié)動態(tài)變化的影響,發(fā)現(xiàn)適度增氮能夠促進水解酶活性,但是增雨在一定程度上會掩蓋增氮的正效應,即未來該地區(qū)降水量的增加將會中和或抑制大氣氮沉降增加對土壤水解酶活性的促進效應。土壤水解酶活性對于全球變化的響應很大程度上依賴于該地區(qū)原有的降水格局以及土壤的營養(yǎng)狀態(tài)。土壤水解酶活性對增氮增雨的不同響應能在一定程度上反映出土壤中相應營養(yǎng)元素的流通狀態(tài),對于草地土壤營養(yǎng)元素循環(huán)具有良好的指示作用。
[Abstract]:Soil Hydrolase can accelerate the degradation process of organic matter in terrestrial ecosystem by catalysis, release nutrients that can be absorbed and used directly by organisms such as plants and microorganisms. Global change can directly or indirectly influence grassland soil enzyme activity and then influence the energy flow and material circulation of grassland ecosystem. In this study, we studied the response of Soil Hydrolase Activity to two global changes - nitrogen deposition and precipitation in the meadow meadow grassland in eastern Inner Mongolia, China. Experimental plots were established in 2010, using nitrogen (N0:0 g N/m2a, N1:5 g N/m2a and N2: 10 g N/m2a) and precipitation (W0: natural precipitation, W1: increase 1/7 self) Precipitation and W2: increased 2/7 natural precipitation) two factors, three level interaction design. In May 2014, July, August and September, 7 soil hydrolase activities were measured, namely alpha glucosidase (alpha G), beta glucosidase (beta G), beta xyleinase (beta X), fiber two sugar hydrolase (CBH), acetaminophen glucosidase (NAG), L- leucine aminopeptidase. LAP) and acid phosphatase (a P), soil physical and chemical properties, aboveground biomass and soil microbial biomass carbon. The following scientific questions are to be answered: 1) how does plant growth peak, different gradient of nitrogen increase, rain increase and two interaction effects on Soil Hydrolase Activity? 2) nitrogen enhancement, precipitation enhancement and the interaction of two parties will be What are the effects of seasonal dynamic changes in Soil Hydrolase Activity? 3) what are the main environmental factors that affect the changes in the activity of Soil Hydrolase under the treatment of nitrogen and precipitation enhancement? (1) the following main conclusions are as follows: (1) the nitrogen treatment at low concentration (5g) significantly improves the activity of Soil Hydrolase at the peak period of plant growth, but with the nitrogen adding ladder In the peak period of plant growth, the low level of precipitation treatment (1/7 natural precipitation) increased the activity of beta G, LAP and a P, and the activity of alpha G, beta G, NAG, LAP and a P were inhibited under the high level precipitation (2/7 natural precipitation) treatment. (2) in the peak period of plant growth, nitrogen and rain enhancement There was a significant interaction between the activity of the soil hydrolase activity to some extent. (3) the effect of nitrogen treatment on Soil Hydrolase Activity in different seasons was improved to some extent, but it did not change the seasonal dynamics of most soil hydrolysate. The activity of Soil Hydrolase in different seasons was inhibited and the variation amplitude of the activity of hydrolase in different seasons was reduced. (4) the main factors that resulted in the change of the activity of Soil Hydrolase were the nitrogen and phosphorus in the soil, and the biological factors such as plants and microbes did not affect the activity of hydrolase in different seasons. Obviously. (5) the effect of nitrogen treatment on the activity of Soil Hydrolase has a certain threshold, that is, the moderate nitrogen increase can promote the enzyme activity, while the amount of nitrogen increasing exceeds the threshold, while the regulation effect of precipitation on Soil Hydrolase is largely influenced by the original water status of the soil and the total rainfall in the year. The response of Soil Hydrolase Activity to different gradients of nitrogen and precipitation in the meadow meadow grassland and the effect of nitrogen and precipitation on the seasonal dynamic changes of soil hydrolase activity were studied. It was found that moderate nitrogen increase could promote the activity of hydrolase, but the positive effect of nitrogen increasing was concealed to some extent, that is, the area decreased in the future. The increase in the amount of water will neutralize or inhibit the effect of the increase of atmospheric nitrogen deposition on the activity of soil hydrolase. The response of Soil Hydrolase to global change depends largely on the original precipitation pattern and the nutritional status of the soil in this region. It reflects the circulation state of the corresponding nutrient elements in the soil, and has a good indication function for the nutrient circulation in the grassland soil.

【學位授予單位】：東北師范大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：S812.2

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