本文選題：土壤無機(jī)呼吸 + 溫度��； 參考：《新疆大學(xué)》2015年碩士論文

【摘要】：全球土壤是一個巨大的碳庫,是大氣CO2重要的來源。據(jù)估計,全球土壤每年排放C量高達(dá)68×1015g/a[1]。由于大氣CO2是引起全球變化的重要溫室氣體。因此,研究土壤呼吸對于探討全球變化及其影響,具有十分重要的意義。土壤呼吸是陸地生態(tài)系統(tǒng)碳循環(huán)的關(guān)鍵環(huán)節(jié),是陸地生態(tài)系統(tǒng)將碳素以CO2形式歸還給大氣的主要途徑。它對環(huán)境因子變化的響應(yīng),在很大程度上決定著全球氣候變化與碳循環(huán)之間的反饋關(guān)系。土壤呼吸作為全球碳循環(huán)的重要組成部分,占整個陸地生態(tài)系統(tǒng)呼吸的60%-90%,是調(diào)控全球碳循環(huán)和氣候變化的關(guān)鍵,其對全球碳循環(huán)的重要作用已經(jīng)逐漸得到廣泛關(guān)注。分析土壤呼吸過程的環(huán)境因子,并且確定其對土壤呼吸速率的影響作用,對于碳循環(huán)的研究具有重要意義。土壤呼吸包括兩方面,一是土壤有機(jī)呼吸即植物根呼吸、土壤微生物呼吸以及土壤動物呼吸。二是土壤無機(jī)呼吸即非生物學(xué)過程(含碳物質(zhì)的化學(xué)氧化作用)。傳統(tǒng)定義上,認(rèn)為土壤有機(jī)呼吸占主導(dǎo)地位,但最近研究發(fā)現(xiàn),土壤無機(jī)呼吸的作用不容小覷。世界干旱土壤占全球陸地總面積的40%,其中大量的土壤無機(jī)碳在全球碳儲存、緩解大氣CO2濃度升高過程中具有重要作用,在全球碳循環(huán)過程中的貢獻(xiàn)日益顯著。中國黃土高原地處干旱、半干旱區(qū),富含碳酸鹽,無機(jī)碳庫是碳庫的主要形式,故探究我國黃土土壤無機(jī)呼吸具有重要的意義。本文以典型的黃土分布區(qū)蘭州市紅古區(qū)所采的黃土為實驗對象,以測定模擬不同溫度(-16℃、4℃、20℃、30℃)、不同降雨量(0.0 mm、2.5mm、5.0mm、15.0mm)以及不同碳酸鈣含量(14%、17%、20%、23%)條件下的黃土土壤無機(jī)呼吸速率以及空氣、土壤溫濕度變化和土壤基本性質(zhì)數(shù)據(jù)為基礎(chǔ),利用相關(guān)分析法,探討黃土土壤無機(jī)呼吸速率的變化特征及其與空氣溫、濕度和土壤溫、濕度等影響因素之間的關(guān)系。并利用回歸分析法分別建立了不同溫度、降雨量以及碳酸鈣條件下的黃土土壤無機(jī)呼吸速率線性及非線性預(yù)測模型,為探討黃土在全球土壤CO2通量變化中的作用提供依據(jù)。主要研究成果與結(jié)論:(1)一般來說,低溫條件下(-16℃),溫度為影響黃土土壤無機(jī)呼吸的主要影響因素。中溫條件下(4℃、20℃),黃土土壤無機(jī)呼吸速率受溫度和濕度的共同作用。高溫條件下(30℃),影響土壤無機(jī)呼吸的主要因素是空氣濕度。(2)無降雨的對照組中,黃土土壤無機(jī)呼吸速率受土壤、空氣溫濕度的共同影響較大。小雨降雨過程中,呼吸速率主要受空氣濕度影響,降雨過后,則受土壤溫濕度的共同作用。中雨條件下,雨中、雨后呼吸速率分別受土壤溫度和空氣濕度的影響較大。大雨情況下,降雨中土壤無機(jī)呼吸速率受土壤溫、濕度和空氣濕度三因素共同影響,雨后則受土壤溫度的作用最大。在本實驗溫度條件下,雨量越大如中雨和大雨,則正呼吸越強(qiáng),而少量的水分(小雨情況)下,黃土土壤無機(jī)呼吸速率更易出現(xiàn)負(fù)值,故推測濕度是影響土壤呼吸可能為負(fù)值的關(guān)鍵因子。(3)黃土土壤中碳酸鈣含量為14%的條件下,土壤無機(jī)呼吸與空氣溫度和土壤溫度相關(guān)性均較好。碳酸鈣含量增加到17%時,呼吸速率與空氣溫、濕度和土壤溫度的相關(guān)性均達(dá)極顯著,而到碳酸鈣達(dá)20%、23%時,其土壤無機(jī)呼吸速率與空氣溫、濕度和土壤溫、濕度均達(dá)極顯著相關(guān)。這說明碳酸鈣含量越高,其土壤無機(jī)呼吸數(shù)量越易受溫、濕度的共同影響。同時隨著碳酸鈣含量的增加,呼吸速率呈減小的趨勢,即土壤呼吸過程中吸收的二氧化碳越多,黃土越易呈“碳匯”。
[Abstract]:Global soil is a huge carbon pool and an important source of atmospheric CO2. It is estimated that global soil emissions of C are as high as 68 * 1015g/a[1]. a year, because atmospheric CO2 is an important greenhouse gas that causes global change. Therefore, it is of great significance to study soil respiration to explore global changes and its effects. Soil respiration is a terrestrial ecology. The key link in the system carbon cycle is the main way for land ecosystem to return carbon to the atmosphere in the form of CO2. Its response to the changes in environmental factors determines the feedback relationship between global climate change and carbon cycle to a large extent. Soil respiration is an important part of the global carbon cycle, accounting for the entire terrestrial ecosystem. The 60%-90% of respiration is the key to the global carbon cycle and climate change, and its important role in the global carbon cycle has been gradually paid attention to. It is of great significance to analyze the environmental factors of soil respiration and to determine its effect on soil respiration rate, which is of great significance to the research of carbon cycle. Soil respiration includes two aspects. Organic respiration of soil is plant root respiration, soil microbial respiration and soil animal respiration. Two is soil inorganic respiration or non biological process (chemical oxidation of carbon material). Traditionally, soil organic respiration is dominant, but recent studies have found that the role of soil inorganic respiration should not be underestimated. Soil accounts for 40% of the total land area of the world, of which a large amount of soil inorganic carbon plays an important role in the global carbon storage, alleviates the increase of atmospheric CO2 concentration, and contributes increasingly to the global carbon cycle. The Loess Plateau in China is located in arid, semi-arid, rich in carbonates and inorganic carbon pools as the main form of carbon storage. The soil inorganic respiration of the Loess Soil in the country is of great significance. In this paper, the loess soil collected in the Lanzhou city of Lanzhou, which is typical of the Loess distribution area, is used to determine the different temperatures (-16, 4, 20, 30), and the different rainfall (0 mm, 2.5mm, 5.0mm, 15.0mm) and the different calcium carbonate content (14%, 17%, 20%, 23%). Based on the data of air, air, air, soil temperature and humidity and soil basic properties, the relationship between the change characteristics of soil inorganic respiration rate and the influence factors such as air temperature, humidity, soil temperature and humidity are discussed by correlation analysis method. The different temperatures and rainfall are established by regression analysis method. The linear and nonlinear prediction model of inorganic respiration rate of loess soil under the condition of calcium carbonate can provide a basis for discussing the effect of loess on the change of CO2 flux in the global soil. The main research results and conclusions are as follows: (1) generally, under low temperature (-16), temperature is the main influence factor of soil inorganic respiration in loess soil. Under the medium temperature condition (4 C, 20 C), the inorganic respiration rate of loess soil is affected by temperature and humidity. Under high temperature (30 degrees C), the main factor affecting the soil inorganic respiration is air humidity. (2) in the control group without rainfall, the soil inorganic respiration rate is affected by the soil and the air temperature and humidity. In the process of rain and rain, the rate of respiration is main. In the rain condition, the respiration rate of the soil is influenced by the soil temperature and the air humidity respectively. In the heavy rain, the soil inorganic respiration rate is affected by three factors, the soil temperature, the humidity and the air humidity, and the soil temperature after the rain. Under the temperature condition of this experiment, the greater the rainfall, such as rain and rain, the stronger the positive respiration, and the less water (small rain), the soil inorganic respiration rate is more liable to negative. Therefore, the humidity is the key factor affecting the soil respiration may be negative. (3) the content of calcium carbonate in the loess soil is 14%. The correlation between soil inorganic respiration and air temperature and soil temperature was better. When calcium carbonate content increased to 17%, the correlation between respiration rate and air temperature, humidity and soil temperature was very significant. When calcium carbonate reached 20%, 23%, the soil inorganic respiration rate was significantly correlated with air temperature, humidity and soil temperature and humidity. The higher the content of calcium carbonate, the more the soil inorganic respiration is affected by temperature and humidity, and with the increase of calcium carbonate content, the rate of respiration is decreasing, that is, the more carbon dioxide absorbed in the soil respiration process, the more easily the loess is "carbon sink".
【學(xué)位授予單位】：新疆大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S154

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 王忠媛;謝江波;王玉剛;李彥;;鹽堿土土壤無機(jī)CO_2通量與土壤鹽堿屬性的關(guān)系[J];生態(tài)學(xué)雜志;2013年10期

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本文編號：1920225