松嫩草原羊草草地的碳儲量現(xiàn)狀及其碳通量對刈割和氮添加的響應(yīng)
發(fā)布時間：2019-05-21 08:19
【摘要】：最近30年來,碳循環(huán)作為陸地生態(tài)系統(tǒng)的重要生態(tài)功能受到前所未有的關(guān)注。草地是全球面積最大的陸地生態(tài)系統(tǒng)類型,割草和放牧是我國草地的最主要利用方式,同時氮沉降是草地生態(tài)系統(tǒng)面臨的重要全球變化因子,然而它們對草地生態(tài)系統(tǒng)碳儲量和碳通量的影響尚未有一致的結(jié)論。松嫩平原羊草草地作為全球氣候變化響應(yīng)的敏感區(qū)和生態(tài)系統(tǒng)脆弱區(qū)域,極易受到人類活動的干擾和全球氣候變暖的影響。2013年和2014年連續(xù)2年采用野外觀測、控制實驗和室內(nèi)分析結(jié)合的方法,對試驗區(qū)羊草草地的植物地上部分、根系、凋落物和土壤的碳含量、生態(tài)系統(tǒng)氣體交換特征等進行了研究,闡明了松嫩平原羊草草地碳儲量現(xiàn)狀以及刈割和氮沉降對松嫩平原羊草草地碳通量的影響。我們的研究結(jié)果表明,2013年和2014年羊草草地碳儲量分別為321.1t/hm2、939.1t/hm2。松嫩平原2014年羊草草地地上地下生物量和草原碳儲量是受2013年降雨量的影響,導(dǎo)致草地理化性質(zhì)發(fā)生改變。2013年形成內(nèi)澇,導(dǎo)致地上地下生物量下降,所以草地碳儲量也相應(yīng)減少,而2014年由于雨量充沛,溫度增高,草地生長狀況良好,地上地下生物量較往年明顯增高,草地碳儲量也明顯增加。本研究在松嫩平原羊草草地通過同化箱法觀測并對比了刈割和模擬氮沉降條件下生態(tài)系統(tǒng)碳通量的變化。結(jié)果表明,無論從季節(jié)動態(tài)還是日動態(tài)來看,氮添加處理的凈生態(tài)系統(tǒng)氣體交換量(NEE)、總生態(tài)系統(tǒng)呼吸(TER)和總生產(chǎn)系統(tǒng)生產(chǎn)力(GEP)總體上均高于對照,而刈割處理的NEE、TER和GEP均低于對照。就土壤呼吸而言,各處理間無顯著差異。整個生長季中對照、刈割和氮添加處理累計碳釋放量分別為107.78g·m-2·year-1、285.20 g·m-2·year-1 和 102.92 g·m-2·year-1。由此看來,整個實驗區(qū)域是碳源,氮素添加可以在一定程度上減弱草地的碳源作用,且有向碳匯轉(zhuǎn)變的趨勢,而高頻次和高強度刈割加重了草地的碳源作用。在生產(chǎn)實踐上建議對草地實行輕度合理放牧和施肥管理,既能加強草地生態(tài)系統(tǒng)的生產(chǎn)功能,也能增加以碳固持為主的生態(tài)功能,從而實現(xiàn)草地生態(tài)系統(tǒng)的可持續(xù)利用。
[Abstract]:In the past 30 years, carbon cycle, as an important ecological function of terrestrial ecosystem, has received unprecedented attention. Grassland is the largest terrestrial ecosystem type in the world. Mowing and grazing are the most important ways of grassland utilization in China, and nitrogen deposition is an important global change factor faced by grassland ecosystem. However, there is no consistent conclusion on their effects on carbon reserves and carbon fluxes in grassland ecosystems. Leymus chinensis grassland in Songnen Plain, as a sensitive area of global climate change response and fragile area of ecosystem, is highly vulnerable to human activities and global warming. Field observations were used for two consecutive years in 2013 and 2014. The above ground part, root system, litter and soil carbon content and ecosystem gas exchange characteristics of Leymus chinensis grassland in the experimental area were studied by means of control experiment and laboratory analysis. The present situation of carbon storage in Leymus chinensis field in Songnen Plain and the effects of cutting and nitrogen deposition on carbon flux of Leymus chinensis grassland in Songnen Plain were expounded. The results of our study show that the carbon storage of Leymus chinensis grassland in 2013 and 2014 is 321.1 t / hm ~ 2939.1t / hm ~ 2. The above-ground and underground biomass and grassland carbon storage of Leymus chinensis grassland in Songnen Plain in 2014 were affected by rainfall in 2013, resulting in changes in physical and chemical properties of grassland. Waterlogging occurred in 2013, resulting in a decrease in above-ground and underground biomass. Therefore, the carbon reserves of grassland also decreased accordingly, but in 2014, due to abundant rainfall and higher temperature, the growth of grassland was good, the above-ground and underground biomass was significantly higher than in previous years, and the carbon storage of grassland was also significantly increased. In this study, the changes of carbon fluxes in ecosystems under cutting and simulated nitrogen deposition were observed and compared by assimilation box method in Songnen Plain Leymus chinensis grassland. The results showed that the net ecosystem gas exchange capacity (NEE), total ecosystem respiration (TER) and total production system productivity (GEP) were higher than those of the control in terms of seasonal and diurnal dynamics. The NEE,TER and GEP of cutting treatment were lower than those of the control. As far as soil respiration was concerned, there was no significant difference among the treatments. In the whole growing season, the cumulative carbon release of cutting and nitrogen addition treatments was 107.78 g 路m-2 路year-1285.20 g 路m-2 路year-1 and 102.92 g 路m-2 路year-1, respectively. Therefore, the whole experimental area is carbon source, nitrogen addition can weaken the carbon source effect of grassland to a certain extent, and there is a tendency to change to carbon sink, while high frequency and high intensity cutting aggravate the carbon source effect of grassland. In production practice, it is suggested that mild and reasonable grazing and fertilizer management of grassland can not only strengthen the production function of grassland ecosystem, but also increase the ecological function of carbon sequestration, so as to realize the sustainable utilization of grassland ecosystem.
【學(xué)位授予單位】：東北林業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S812
[Abstract]:In the past 30 years, carbon cycle, as an important ecological function of terrestrial ecosystem, has received unprecedented attention. Grassland is the largest terrestrial ecosystem type in the world. Mowing and grazing are the most important ways of grassland utilization in China, and nitrogen deposition is an important global change factor faced by grassland ecosystem. However, there is no consistent conclusion on their effects on carbon reserves and carbon fluxes in grassland ecosystems. Leymus chinensis grassland in Songnen Plain, as a sensitive area of global climate change response and fragile area of ecosystem, is highly vulnerable to human activities and global warming. Field observations were used for two consecutive years in 2013 and 2014. The above ground part, root system, litter and soil carbon content and ecosystem gas exchange characteristics of Leymus chinensis grassland in the experimental area were studied by means of control experiment and laboratory analysis. The present situation of carbon storage in Leymus chinensis field in Songnen Plain and the effects of cutting and nitrogen deposition on carbon flux of Leymus chinensis grassland in Songnen Plain were expounded. The results of our study show that the carbon storage of Leymus chinensis grassland in 2013 and 2014 is 321.1 t / hm ~ 2939.1t / hm ~ 2. The above-ground and underground biomass and grassland carbon storage of Leymus chinensis grassland in Songnen Plain in 2014 were affected by rainfall in 2013, resulting in changes in physical and chemical properties of grassland. Waterlogging occurred in 2013, resulting in a decrease in above-ground and underground biomass. Therefore, the carbon reserves of grassland also decreased accordingly, but in 2014, due to abundant rainfall and higher temperature, the growth of grassland was good, the above-ground and underground biomass was significantly higher than in previous years, and the carbon storage of grassland was also significantly increased. In this study, the changes of carbon fluxes in ecosystems under cutting and simulated nitrogen deposition were observed and compared by assimilation box method in Songnen Plain Leymus chinensis grassland. The results showed that the net ecosystem gas exchange capacity (NEE), total ecosystem respiration (TER) and total production system productivity (GEP) were higher than those of the control in terms of seasonal and diurnal dynamics. The NEE,TER and GEP of cutting treatment were lower than those of the control. As far as soil respiration was concerned, there was no significant difference among the treatments. In the whole growing season, the cumulative carbon release of cutting and nitrogen addition treatments was 107.78 g 路m-2 路year-1285.20 g 路m-2 路year-1 and 102.92 g 路m-2 路year-1, respectively. Therefore, the whole experimental area is carbon source, nitrogen addition can weaken the carbon source effect of grassland to a certain extent, and there is a tendency to change to carbon sink, while high frequency and high intensity cutting aggravate the carbon source effect of grassland. In production practice, it is suggested that mild and reasonable grazing and fertilizer management of grassland can not only strengthen the production function of grassland ecosystem, but also increase the ecological function of carbon sequestration, so as to realize the sustainable utilization of grassland ecosystem.
【學(xué)位授予單位】：東北林業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S812
【參考文獻】
相關(guān)期刊論文 前10條
1 楊婷婷;吳新宏;王加亭;李鵬;石紅霄;;中國草地生態(tài)系統(tǒng)碳儲量估算[J];干旱區(qū)資源與環(huán)境;2012年03期
2 朱玲玲;戎郁萍;王偉光;馬磊;;放牧對草地生態(tài)系統(tǒng)CO_2凈氣體交換影響研究概述[J];草地學(xué)報;2013年01期
3 呼天明;;羊草草原氮素循環(huán)之研究[J];家畜生態(tài);1991年03期
4 蔣麗;祝廷成;馬略耕;石連旋;侯文娟;郭繼勛;;松嫩草地碳和水通量對全球變化的響應(yīng)[J];科技導(dǎo)報;2011年06期
5 何念鵬;韓興國;于貴瑞;;內(nèi)蒙古放牧草地土壤碳固持速率和潛力[J];生態(tài)學(xué)報;2012年03期
6 馬紅亮;王杰;高人;尹云鋒;孫杰;;施用銨態(tài)氮對森林土壤硝態(tài)氮和銨態(tài)氮的影響[J];土壤;2011年06期
7 邢爽;張思沖;許瀛元;;黑龍江省森工林區(qū)野生植物碳匯效益研究[J];森林工程;2013年02期
8 宗寧;石培禮;，
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