【摘要】：青藏高原既是我國重要的特色畜牧業(yè)基地,同時也對北半球的氣候有著重要影響,更是我國及周邊國家多條母親河的發(fā)源地,對我國東部及西南部生態(tài)環(huán)境和社會經(jīng)濟(jì)有巨大影響。青藏高原總面積的85%是高寒草地,是藏羊和牦牛放牧的主要草場,高寒草地在氣候調(diào)節(jié)、多樣性保護(hù)和水土保持等生態(tài)服務(wù)功能發(fā)揮著重要影響,也對區(qū)域生態(tài)系統(tǒng)碳庫平衡具有十分重要的作用。然而,受全球性氣候干旱、牧區(qū)人口增加、草原人為活動破壞和長期不合理的放牧利用模式等影響,青藏高原高寒草地退化嚴(yán)重。放牧是草地最主要的利用方式。目前,青藏高原高寒草地通常是整季,甚至全年連續(xù)放牧利用,過度放牧嚴(yán)重,這種不合理的利用方式對草地的破壞極大,尤其是在牧草返青期間,剛剛萌發(fā)返青的幼苗被采食后光合面積迅速減少,嚴(yán)重影響后期的生長和發(fā)育。合理放牧?xí)r期的確定,是草地實現(xiàn)休養(yǎng)生息,保持草地健康發(fā)展和可持續(xù)利用的重要手段。然而,不同放牧管理模式下,高寒草甸植被的結(jié)構(gòu)和組成、土壤理化特征及碳氮儲量特征的的變化尚不明確。因此,本研究以青藏高原東緣禁牧(NG)、全生長季休牧(RG)、傳統(tǒng)放牧(TG)和連續(xù)放牧(CG)4種不同放牧管理模式高寒草甸為研究對象,以群落生態(tài)學(xué)原理為指導(dǎo),通過野外調(diào)查與室內(nèi)分析相結(jié)合,研究了不同放牧管理模式對高寒草甸植被、土壤理化特征和碳氮儲量特征的影響,以闡明不同放牧管理對高寒草甸生態(tài)系統(tǒng)的作用,在此基礎(chǔ)上,探尋適宜于該地區(qū)的最佳放牧管理模式,從而為高寒草地碳匯管理、天然草地退化及修復(fù)治理提供理論基礎(chǔ)。本研究得出以下結(jié)果:1.與CG處理相比,NG和RG處理顯著增加了垂穗披堿草(Elymus nutans)和冷地早熟禾(Poa crymophila)的重要值、各功能群(禾本科、莎草科、豆科和雜類草)植物的高度、禾本科植物密度和生物量以及總地上、地下生物量,其中以NG樣地效果最為明顯;降低雜類草植物的重要值、地下與地上生物量的比值、雜類草的生物量和密度;在4種放牧模式中,Shannon-Wiener指數(shù)(H)、Pielou均勻度指數(shù)(J)和豐富度指數(shù)(S)及群落總密度的排列順序均為:CGNGTGRG。2.與CG處理相比,NG和RG改良了高寒草甸0~20 cm土壤物理結(jié)構(gòu),降低了土壤的緊實度,但對深層土壤影響較小;NG和RG不同程度地改善了高寒草甸土壤的持水能力。NG顯著增加了0~30 cm土壤有機(jī)質(zhì)含量,RG和TG顯著增加了0~20 cm土壤有機(jī)質(zhì)含量。NG,RG和TG顯著提高了高寒草甸0~30 cm土壤全氮含量和20~30 cm土壤速效氮含量,而降低了0~10 cm土壤的速效氮含量。NG,RG和TG顯著提高了高寒草甸0~30 cm土壤全磷和速效磷含量。不同模式放牧對高寒草甸土壤全鉀含量無顯著影響,但總體上,NG,RG和TG高于CG;NG,RG和TG降低了0~10 cm土層速效鉀含量,而顯著增加了10~30 cm土層速效鉀含量。3.高寒草甸土壤呼吸速率月動態(tài)均表現(xiàn)出先增加后降低的變化態(tài)勢,峰值出現(xiàn)在8月;在整個生長季,NG,RG和TG高寒草甸平均土壤呼吸值顯著高于CG樣地,其中,NG和RG間無顯著差異,但顯著高于TG;土壤含水量對土壤呼吸通量的影響存在一個閾值,30%左右為臨界值,在此之前二者呈正相關(guān),此后呈負(fù)相關(guān)。4.NG,RG和TG較CG顯著提高了土壤、根系、植被和凋落物有機(jī)碳、氮儲量。高寒草甸生態(tài)系統(tǒng)中,土壤中有機(jī)碳儲量所占比例最大(88.8%-98.2%),其次為根系(1.6%-8.7%),再次為植被(0.17%-1.43%),最小為凋落物(0.022%-0.97%);氮儲量占比例最大的是土壤(97.3%-99.6%),其次為根系(0.32%-2.07%),再次為植被(0.05%-0.44%),凋落物最小(0.003%-0.16%)。不同放牧管理模式下土壤有機(jī)碳、氮儲量具有明顯的垂直分布特征,隨土壤深度的增加土壤有機(jī)碳、氮儲量明顯降低。短期不同放牧模式僅對0~40 cm土層土壤有機(jī)碳、氮儲量有影響。土壤有機(jī)碳、氮儲量主要分布在0~40 cm土層,同時,放牧有使有機(jī)碳、氮向深層轉(zhuǎn)移的趨勢。NG、RG和TG顯著提高了高寒草甸生態(tài)系統(tǒng)總有機(jī)碳、氮儲量,而CG顯著降低了總有機(jī)碳、氮儲量,導(dǎo)致有機(jī)碳、氮的流失。綜上所述,禁牧和全生長季休牧均能有效恢復(fù)青藏高原東緣退化草地生態(tài)系統(tǒng)�？紤]到草地資源的更新、均衡利用和牧民經(jīng)濟(jì)收入等,全生長季休牧既可充分利用牧草資源,有利于草地的生態(tài)恢復(fù)及可持續(xù)發(fā)展,是青藏高原高寒草甸類草地放牧管理的理想選擇。同時,建議禁牧的同時,可采取其他一些人為干預(yù)措施(如非生長季放牧利用等)。
[Abstract]:The Qinghai-Tibet Plateau is not only an important characteristic animal husbandry base in China, but also has an important impact on the climate of the northern hemisphere. It is also the birthplace of many mother rivers in China and its surrounding countries. It has a great impact on the ecological environment and social economy in the eastern and southwestern parts of China. Major grasslands and alpine grasslands play an important role in climate regulation, diversity protection and soil and water conservation. They also play an important role in the balance of carbon pools in regional ecosystems. At present, Alpine Grassland in the Qinghai-Tibet Plateau is usually grazed continuously throughout the whole season, even throughout the year. Overgrazing is serious. This unreasonable use of alpine grassland has caused great damage to the grassland, especially during the period of grass turning green, the seedlings just germinating and turning green are picked. The photosynthetic area of alpine meadow decreased rapidly after grazing, which seriously affected the growth and development of grassland in the later period.The determination of reasonable grazing period is an important means to realize the recuperation, maintain the healthy development and sustainable utilization of grassland.However, under different grazing management modes, the structure and composition of alpine meadow vegetation, soil physicochemical characteristics and carbon and nitrogen storage characteristics. In this study, alpine meadows with four different grazing management modes (NG, RG, TG and CG) were selected as the research objects. Based on the principles of community ecology, different grazing management modes were studied through field investigation and indoor analysis. The effects of different grazing management on alpine meadow ecosystem were clarified. On this basis, the best grazing management model suitable for the region was explored, which provided theoretical basis for carbon sink management of alpine meadow, degradation and restoration of natural grassland. Compared with CG treatment, NG and RG treatment significantly increased the important values of Elymus nutans and Poa crymophila, the plant height of functional groups (Gramineae, Cyperaceae, Leguminosae and Weeds), the density and biomass of Gramineae plants, and the total aboveground and underground biomass, of which NG was the most effective. In order to reduce the important value of weeds, the ratio of underground and aboveground biomass, the biomass and density of weeds, the order of Shannon-Wiener index (H), Pielou evenness index (J), richness index (S) and total community density in four grazing patterns were: CGNGTGRG.2. Compared with CG treatment, NG and RG improved alpine meadow 0. The physical structure of ~20 cm soil decreased soil compactness, but had little effect on deep soil; NG and RG improved water holding capacity of alpine meadow soil to some extent. NG significantly increased soil organic matter content of 0~30 cm, RG and TG significantly increased soil organic matter content of 0~20 cm. NG, RG and TG significantly increased total soil organic matter content of 0~30 cm in alpine meadow soil. NG, RG and TG significantly increased soil total phosphorus and available phosphorus content in 0-30 cm alpine meadow. Different grazing patterns had no significant effect on total potassium content in alpine meadow soil, but in general, NG, RG and TG were higher than CG, RG and TG were lower than CG, RG and TG in 0-10 cm soil layer. The monthly dynamics of soil respiration rate in alpine meadow showed a trend of increasing first and then decreasing, and the peak value appeared in August. In the whole growing season, the average soil respiration value of NG, RG and TG in alpine meadow was significantly higher than that of CG plot, and there was no significant difference between NG and RG, but significantly higher than that of TG. There was a threshold value of soil water content on soil respiration flux, about 30% was the critical value, before which there was a positive correlation between them, and after that there was a negative correlation between them.4.NG, RG and TG significantly increased soil, root, vegetation and litter organic carbon, nitrogen storage than CG. In alpine meadow ecosystem, soil organic carbon storage accounted for the largest proportion (88.8% - 98%). 2%, followed by root system (1.6% - 8.7%), vegetation (0.17% - 1.43%) and litter (0.022% - 0.97%); soil organic carbon (97.3% - 99.6%) accounted for the largest proportion of nitrogen storage, followed by root system (0.32% - 2.07%), vegetation (0.05% - 0.44%) and litter (0.003% - 0.16%). Soil organic carbon and nitrogen storage were mainly distributed in 0-40 cm soil layer. At the same time, grazing tended to make organic carbon and nitrogen transfer to deeper layer. NG, RG and TG increased significantly. The total organic carbon and nitrogen reserves of the cold meadow ecosystem were significantly reduced by CG, which led to the loss of organic carbon and nitrogen. In conclusion, grazing prohibition and rest in the whole growing season could effectively restore the degraded grassland ecosystem in the eastern margin of the Qinghai-Tibet Plateau. Rest grazing can make full use of grassland resources, which is conducive to ecological restoration and sustainable development of grassland. It is an ideal choice for grazing management of alpine meadow grassland in Qinghai-Tibet Plateau.
【學(xué)位授予單位】：甘肅農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：S812.8

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 李英年,周華坤,沈振西;高寒草甸牧草產(chǎn)量形成過程及與氣象因子的關(guān)聯(lián)分析[J];草地學(xué)報;2001年03期

2 姚德良,張強(qiáng),沈振西,謝正桐;高寒草甸小氣候考察研究[J];草地學(xué)報;2003年04期

3 王慧春;趙修堂;王啟蘭;;青海高寒草甸不同植被土壤微生物生物量的測定[J];青海草業(yè);2006年04期

4 吳世仁;馬玉秀;;甘南州高寒草甸草原昆蟲區(qū)系調(diào)查簡報[J];甘肅農(nóng)業(yè);2008年02期

5 梁東營;林麗;李以康;王溪;曹廣民;;三江源退化高寒草甸草氈表層剝蝕過程及發(fā)生機(jī)理的初步研究[J];草地學(xué)報;2010年01期

6 范曉梅;劉光生;王一博;任東興;王根緒;;長江源區(qū)高寒草甸植被覆蓋變化對蒸散過程的影響[J];水土保持通報;2010年06期

7 羅亞勇;張宇;張靜輝;卡召加;尚倫宇;王少影;;不同退化階段高寒草甸土壤化學(xué)計量特征[J];生態(tài)學(xué)雜志;2012年02期

8 張裴雷;方華軍;程淑蘭;徐敏杰;李林森;黨旭升;;增氮對青藏高原東緣高寒草甸土壤甲烷吸收的早期影響[J];生態(tài)學(xué)報;2013年13期

9 虎彪;;金川縣高寒草甸植被的特征及其利用途徑的初步探討[J];中國牦牛;1985年04期

10 劉海原;;玉樹地區(qū)高寒草甸的類型及其利用價值[J];青海畜牧獸醫(yī)雜志;1988年03期

相關(guān)會議論文 前10條

1 曹廣民;杜巖功;梁東營;王長庭;王啟蘭;;高寒草甸兩種類型植物對甲烷匯的影響[A];青藏高原資源·環(huán)境·生態(tài)建設(shè)學(xué)術(shù)研討會暨中國青藏高原研究會2007學(xué)術(shù)年會論文摘要匯編[C];2007年

2 李月梅;曹廣民;;土地利用方式改變對高寒草甸土壤有機(jī)碳的影響的初步研究[A];2005青藏高原環(huán)境與變化研討會論文摘要匯編[C];2005年

3 王秀紅;鄭度;;青藏高原高寒草甸資源的可持續(xù)利用[A];面向21世紀(jì)的科技進(jìn)步與社會經(jīng)濟(jì)發(fā)展（上冊）[C];1999年

4 王文穎;;高寒草甸土地退化及其恢復(fù)重建對植被碳氮含量的影響[A];第三屆全國植物生態(tài)學(xué)前沿論壇第三屆全國克隆植物生態(tài)學(xué)研討會論文摘要匯編[C];2009年

5 張力;劉彩琴;鄭中朝;周學(xué)輝;肖西山;焦婷;馮瑞林;李偉;苗小林;;青海三角城種羊場高寒草甸草場氮、硫的季節(jié)變化及其盈缺分析[A];全國養(yǎng)羊生產(chǎn)與學(xué)術(shù)研討會議論文集（2003～2004）[C];2004年

6 姚德良;張強(qiáng);謝正桐;;高寒草甸陸氣水熱交換數(shù)值模擬研究[A];第十七屆全國水動力學(xué)研討會暨第六屆全國水動力學(xué)學(xué)術(shù)會議文集[C];2003年

7 孫飛達(dá);龍瑞軍;;鼠類活動對三江源區(qū)高寒草甸初級生產(chǎn)力的影響[A];2009中國草原發(fā)展論壇論文集[C];2009年

8 陶貞;沈承德;孫彥敏;高全洲;易惟熙;李英年;;土地利用變化對高寒草甸土壤有機(jī)質(zhì)更新的影響[A];中國地理學(xué)會2004年學(xué)術(shù)年會暨海峽兩岸地理學(xué)術(shù)研討會論文摘要集[C];2004年

9 李希來;張靜;;青藏高原“黑土灘”形成的自然因素與生物學(xué)機(jī)制[A];草業(yè)與西部大開發(fā)——草業(yè)與西部大開發(fā)學(xué)術(shù)研討會暨中國草原學(xué)會2000年學(xué)術(shù)年會論文集[C];2000年

10 孫平;趙新全;徐世曉;趙同標(biāo);趙偉;;冬季根田鼠(MICROTUS OECONOMUS)種群對實驗增溫響應(yīng)的初步研究[A];野生動物生態(tài)與管理學(xué)術(shù)討論會論文摘要集[C];2001年

相關(guān)重要報紙文章 前2條

1 記者 張目 朱國亮;豐腴的青藏高寒草甸草枯畜減[N];新華每日電訊;2003年

2 陳建明;漫游伊犁草原[N];中國綠色時報;2002年

相關(guān)博士學(xué)位論文 前10條

1 毛琳;資源有效性對植物及其共生叢枝菌根真富群落的調(diào)控機(jī)制研究[D];蘭州大學(xué);2015年

2 苗福泓;青藏高原東北緣草地植物群落對放牧利用強(qiáng)度和降水變異的響應(yīng)[D];蘭州大學(xué);2015年

3 蘆曉飛;西藏米拉山高寒草甸土壤微生物多樣性研究[D];中國農(nóng)業(yè)科學(xué)院;2009年

4 王輝;瑪曲高寒草甸沙化特征及沙化驅(qū)動機(jī)制研究[D];蘭州大學(xué);2007年

5 張世虎;青藏高原東部高寒草甸土壤氮的礦化和硝化及地上地下關(guān)系的研究[D];蘭州大學(xué);2011年

6 章志龍;氮素添加對青藏高原東緣高寒草甸植物群落花期物候和群落結(jié)構(gòu)的影響[D];蘭州大學(xué);2013年

7 劉佳佳;青藏高原高寒草甸草本植物的空間格局及其形成機(jī)制[D];蘭州大學(xué);2012年

8 文淑均;青藏高原東緣高寒草甸種子雨研究[D];蘭州大學(xué);2012年

9 劉e，

本文編號：2223269