增温对青藏高原高寒草原生态系统碳交换的影响
|
摘要
碳交换是影响草地生态系统碳汇功能的关键过程,对气候变暖极为敏感。青藏高原分布着大面积的高寒草原,其碳汇功能对气候变暖的响应对区域碳循环过程具有重要的影响。为探究高寒草原生态系统碳交换过程对增温的响应,2012—2014年,在青藏高原班戈县进行了模拟增温对高寒草原生态系统碳交换过程影响的研究。结果表明,增温对高寒草原碳交换各组分的影响存在年际差异,但总体上对碳交换存在负面影响。3年平均结果显示,增温显著降低了高寒草原地上生物量、总生态系统生产力(GEP)、生态系统呼吸(ER)和净生态系统碳交换量(NEE)(P<0.05),平均降幅分别为15.1%、36.8%、19.2%和51.5%。增温条件下3年平均土壤呼吸(SR)较对照无显著变化(P>0.05),但2013年增温显著降低了SR(P<0.05),降幅达18.1%。增温对SR与ER的比值具有一定的促进作用,最高增幅达到40.0%。GEP、ER、SR和NEE与土壤温度和土壤水分无显著相关(P>0.05),而GEP、ER和NEE与空气温度呈显著的负相关关系(P<0.05)。增温引起的干旱胁迫以及地上生物量降低是导致高寒草原NEE降低的主要原因。研究表明,全球变暖会一定程度降低青藏高原高寒草原的碳汇功能。
Carbon exchange is a key process that affects the carbon sink capacity of grassland ecosystems and is very sensitive to climate warming. The Tibetan Plateau is covered by large areas of alpine steppe, which is the main carbon pool and fundamental in regional carbon cycling. The present study investigated the effects of warming on carbon exchange in an alpine steppe ecosystem in Baingoin County, Tibetan Plateau from 2012 to 2014. The results showed that there are interannual differences in the effects of warming on the components of carbon exchange in alpine steppes, but there is a negative effect on carbon exchange as a whole. Three-year average results showed that warming significantly reduced the above-ground biomass, gross ecosystem productivity(GEP), ecosystem respiration(ER), and net ecosystem carbon exchange(NEE) in the alpine steppe(P<0.05), with an average decrease of 15.1%, 36.8%, 19.2%, and 51.5%, respectively. Three-year average soil respiration(SR) did not change significantly(P>0.05) compared with the control under warming conditions, but warming in 2013 significantly reduced SR(P<0.05), by 18.1%. Warming has a certain role in promoting the ratio of SR to ER, with the highest increase reaching 40.0%. GEP, ER, SR, and NEE had no significant correlation with soil temperature and soil moisture(P>0.05), whereas GEP, ER, and NEE showed a significant negative correlation with air temperature(P<0.05). A decrease in drought stress and above-ground biomass caused by warming were the main factors for the decrease of NEE in the alpine steppe. In summary, our study showed that global warming may reduce the carbon sink capacity of alpine steppes in the Tibetan Plateau.
Carbon exchange is a key process that affects the carbon sink capacity of grassland ecosystems and is very sensitive to climate warming. The Tibetan Plateau is covered by large areas of alpine steppe, which is the main carbon pool and fundamental in regional carbon cycling. The present study investigated the effects of warming on carbon exchange in an alpine steppe ecosystem in Baingoin County, Tibetan Plateau from 2012 to 2014. The results showed that there are interannual differences in the effects of warming on the components of carbon exchange in alpine steppes, but there is a negative effect on carbon exchange as a whole. Three-year average results showed that warming significantly reduced the above-ground biomass, gross ecosystem productivity(GEP), ecosystem respiration(ER), and net ecosystem carbon exchange(NEE) in the alpine steppe(P<0.05), with an average decrease of 15.1%, 36.8%, 19.2%, and 51.5%, respectively. Three-year average soil respiration(SR) did not change significantly(P>0.05) compared with the control under warming conditions, but warming in 2013 significantly reduced SR(P<0.05), by 18.1%. Warming has a certain role in promoting the ratio of SR to ER, with the highest increase reaching 40.0%. GEP, ER, SR, and NEE had no significant correlation with soil temperature and soil moisture(P>0.05), whereas GEP, ER, and NEE showed a significant negative correlation with air temperature(P<0.05). A decrease in drought stress and above-ground biomass caused by warming were the main factors for the decrease of NEE in the alpine steppe. In summary, our study showed that global warming may reduce the carbon sink capacity of alpine steppes in the Tibetan Plateau.
引文
[1] 曹明奎,李克让.陆地生态系统与气候相互作用的研究进展.地球科学进展,2000,15(4):446- 452.
[2] 张金霞,曹广民,周党卫,胡启武,赵新全.高寒矮嵩草草甸大气-土壤-植被-动物系统碳素储量及碳素循环.生态学报,2003,23(4):627- 634.
[3] 张镱锂,李炳元,郑度.论青藏高原范围与面积.地理研究,2002,21(1):1- 8.
[4] 高清竹,段敏杰,万运帆,李玉娥,郭亚奇,江村旺扎.藏北地区生态与环境敏感性评价.生态学报,2010,30(15):4129- 4136.
[5] Liu X D,Chen B D.Climatic warming in the Tibetan plateau during recent decades.International Journal of Climatology,2000,20(14):1729- 1742.
[6] 郑度,林振耀,张雪芹.青藏高原与全球环境变化研究进展.地学前缘,2002,9(1):95- 102.
[7] Liu X D,Yin Z Y.Sensitivity of East Asian monsoon climate to the uplift of the Tibetan Plateau.Palaeogeography,Palaeoclimatology,Palaeoecology,2002,183(3/4):223- 245.
[8] Grabherr G,Gottfried M,Pauli H.Climate effects on mountain plants.Nature,1994,369(6480):448- 448.
[9] Jarvis A J,Stauch V J,Schulz K S,Young P C.The seasonal temperature dependency of photosynthesis and respiration in two deciduous forests.Global Change Biology,2004,10(6):939- 950.
[10] 亓伟伟,牛海山,汪诗平,刘艳杰,张立荣.增温对青藏高原高寒草甸生态系统固碳通量影响的模拟研究.生态学报,2012,32(6):1713- 1722.
[11] Lin X W,Zhang Z H,Wang S P,Hu Y G,Xu G P,Luo C Y,Chang X F,Duan J C,Lin Q Y,Xu B,Wang Y F,Zhao X Q,Xie Z B.Response of ecosystem respiration to warming and grazing during the growing seasons in the alpine meadow on the Tibetan plateau.Agricultural and Forest Meteorology,2011,151(7):792- 802.
[12] 耿晓东,旭日.梯度增温对青藏高原高寒草甸生态系统碳交换的影响.草业科学,2017,34(12):2407- 2415.
[13] Ganjurjav H,Gao Q,Zhang W,Liang Y,Li Y W,Cao X J,Wan Y F,Li Y,Danjiu L B.Effects of warming on CO2 fluxes in an alpine meadow ecosystem on the central Qinghai-Tibetan Plateau.PLoS One,2015,10(7):e0132044.
[14] Xia J Y,Niu S L,Wan S Q.Response of ecosystem carbon exchange to warming and nitrogen addition during two hydrologically contrasting growing seasons in a temperate steppe.Global Change Biology,2009,15(6):1544- 1556.
[15] Trumbore S.Carbon respired by terrestrial ecosystems-receent progress and challenges.Global Change Biology,2006,12(2):141- 153.
[16] 刘福娟.光合作用的影响因素分析.农机化研究,2004,(4):237- 237.
[17] Xu Z Z,Zhou G S.Effects of water stress on photosynthesis and nitrogen metabolism in vegetative and reproductive shoots of Leymus chinensis.Photosynthetica,2005,43(1):29- 35.
[18] Wertin T M,Belnap J,Reed S C.Experimental warming in a dryland community reduced plant photosynthesis and soil CO2 efflux although the relationship between the fluxes remained unchanged.Functional Ecology,2017,31(2):297- 305.
[19] 郭亚奇,阿里穆斯,高清竹,段敏杰,干珠扎布,万运帆,李玉娥,郭红保.灌溉条件下藏北紫花针茅光合特性及其对温度和CO2浓度的短期响应.植物生态学报,2011,35(3):311- 321.
[20] 胡中民,于贵瑞,樊江文,温学发.干旱对陆地生态系统水碳过程的影响研究进展.地理科学进展,2006,25(6):12- 20.
[21] 王云龙,许振柱,周广胜.水分胁迫对羊草光合产物分配及其气体交换特征的影响.植物生态学报,2004,28(6):803- 809.
[22] 李军祥,曾辉,朱军涛,张扬建,陈宁,刘瑶杰.藏北高原高寒草甸生态系统呼吸对增温的响应.生态环境学报,2016,25(10):1612- 1620.
[23] Fu G,Shen Z X,Zhang X Z,Yu C Q,Zhou Y T,Li Y L,Yang P W.Response of ecosystem respiration to experimental warming and clipping at daily time scale in an alpine meadow of Tibet.Journal of Mountain Science,2013,10(3):455- 463.
[24] Wang W,Guo J X,Oikawa T.Contribution of root to soil respiration and carbon balance in disturbed and undisturbed grassland communities,northeast China.Journal of Biosciences,2007,32(2):375- 384.
[25] 王娓,汪涛,彭书时,方精云.冬季土壤呼吸:不可忽视的地气CO2交换过程.植物生态学报,2007,31(3):394- 402.
[26] Peng F,You Q G,Xu M H,Guo J,Wang T,Xue X.Effects of warming and clipping on ecosystem carbon fluxes across two hydrologically contrasting years in an alpine meadow of the Qinghai-Tibet Plateau.PLoS One,2014,9(10):e109319.
[2] 张金霞,曹广民,周党卫,胡启武,赵新全.高寒矮嵩草草甸大气-土壤-植被-动物系统碳素储量及碳素循环.生态学报,2003,23(4):627- 634.
[3] 张镱锂,李炳元,郑度.论青藏高原范围与面积.地理研究,2002,21(1):1- 8.
[4] 高清竹,段敏杰,万运帆,李玉娥,郭亚奇,江村旺扎.藏北地区生态与环境敏感性评价.生态学报,2010,30(15):4129- 4136.
[5] Liu X D,Chen B D.Climatic warming in the Tibetan plateau during recent decades.International Journal of Climatology,2000,20(14):1729- 1742.
[6] 郑度,林振耀,张雪芹.青藏高原与全球环境变化研究进展.地学前缘,2002,9(1):95- 102.
[7] Liu X D,Yin Z Y.Sensitivity of East Asian monsoon climate to the uplift of the Tibetan Plateau.Palaeogeography,Palaeoclimatology,Palaeoecology,2002,183(3/4):223- 245.
[8] Grabherr G,Gottfried M,Pauli H.Climate effects on mountain plants.Nature,1994,369(6480):448- 448.
[9] Jarvis A J,Stauch V J,Schulz K S,Young P C.The seasonal temperature dependency of photosynthesis and respiration in two deciduous forests.Global Change Biology,2004,10(6):939- 950.
[10] 亓伟伟,牛海山,汪诗平,刘艳杰,张立荣.增温对青藏高原高寒草甸生态系统固碳通量影响的模拟研究.生态学报,2012,32(6):1713- 1722.
[11] Lin X W,Zhang Z H,Wang S P,Hu Y G,Xu G P,Luo C Y,Chang X F,Duan J C,Lin Q Y,Xu B,Wang Y F,Zhao X Q,Xie Z B.Response of ecosystem respiration to warming and grazing during the growing seasons in the alpine meadow on the Tibetan plateau.Agricultural and Forest Meteorology,2011,151(7):792- 802.
[12] 耿晓东,旭日.梯度增温对青藏高原高寒草甸生态系统碳交换的影响.草业科学,2017,34(12):2407- 2415.
[13] Ganjurjav H,Gao Q,Zhang W,Liang Y,Li Y W,Cao X J,Wan Y F,Li Y,Danjiu L B.Effects of warming on CO2 fluxes in an alpine meadow ecosystem on the central Qinghai-Tibetan Plateau.PLoS One,2015,10(7):e0132044.
[14] Xia J Y,Niu S L,Wan S Q.Response of ecosystem carbon exchange to warming and nitrogen addition during two hydrologically contrasting growing seasons in a temperate steppe.Global Change Biology,2009,15(6):1544- 1556.
[15] Trumbore S.Carbon respired by terrestrial ecosystems-receent progress and challenges.Global Change Biology,2006,12(2):141- 153.
[16] 刘福娟.光合作用的影响因素分析.农机化研究,2004,(4):237- 237.
[17] Xu Z Z,Zhou G S.Effects of water stress on photosynthesis and nitrogen metabolism in vegetative and reproductive shoots of Leymus chinensis.Photosynthetica,2005,43(1):29- 35.
[18] Wertin T M,Belnap J,Reed S C.Experimental warming in a dryland community reduced plant photosynthesis and soil CO2 efflux although the relationship between the fluxes remained unchanged.Functional Ecology,2017,31(2):297- 305.
[19] 郭亚奇,阿里穆斯,高清竹,段敏杰,干珠扎布,万运帆,李玉娥,郭红保.灌溉条件下藏北紫花针茅光合特性及其对温度和CO2浓度的短期响应.植物生态学报,2011,35(3):311- 321.
[20] 胡中民,于贵瑞,樊江文,温学发.干旱对陆地生态系统水碳过程的影响研究进展.地理科学进展,2006,25(6):12- 20.
[21] 王云龙,许振柱,周广胜.水分胁迫对羊草光合产物分配及其气体交换特征的影响.植物生态学报,2004,28(6):803- 809.
[22] 李军祥,曾辉,朱军涛,张扬建,陈宁,刘瑶杰.藏北高原高寒草甸生态系统呼吸对增温的响应.生态环境学报,2016,25(10):1612- 1620.
[23] Fu G,Shen Z X,Zhang X Z,Yu C Q,Zhou Y T,Li Y L,Yang P W.Response of ecosystem respiration to experimental warming and clipping at daily time scale in an alpine meadow of Tibet.Journal of Mountain Science,2013,10(3):455- 463.
[24] Wang W,Guo J X,Oikawa T.Contribution of root to soil respiration and carbon balance in disturbed and undisturbed grassland communities,northeast China.Journal of Biosciences,2007,32(2):375- 384.
[25] 王娓,汪涛,彭书时,方精云.冬季土壤呼吸:不可忽视的地气CO2交换过程.植物生态学报,2007,31(3):394- 402.
[26] Peng F,You Q G,Xu M H,Guo J,Wang T,Xue X.Effects of warming and clipping on ecosystem carbon fluxes across two hydrologically contrasting years in an alpine meadow of the Qinghai-Tibet Plateau.PLoS One,2014,9(10):e109319.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |