Effects of cloudiness change on net ecosystem exchange, light use efficiency, and water use efficiency in typical ecosystems of China

	Effects of cloudiness change on net ecosystem exchange, light use efficiency, and water use efficiency in typical ecosystems of China
	Zhang, Mi 1,2; Yu, Gui-Rui 1; Zhuang, Jie 3; Gentry, Randy 3; Fu, Yu-Ling 1; Sun, Xiao-Min 1; Zhang, Lei-Ming 1; Wen, Xue-Fa 1; Wang, Qiu-Feng 1; Han, Shi-Jie 4
刊名	agricultural and forest meteorology
	2011-07-15
卷号	151 期号:7 页码:803-816
关键词	Cloudiness Terrestrial ecosystem Net ecosystem exchange of carbon dioxide Light use efficiency Water use efficiency
ISSN号	0168-1923
中文摘要	as a weather element, clouds can affect co(2) exchange between terrestrial ecosystems and the atmosphere by altering environmental conditions, such as solar radiation received on the ground surface, temperature, and moisture. based on the flux data measured at five typical ecosystems of china during mid-growing season (june-august) from 2003 to 2006, we analyzed the responses of net ecosystem exchange of carbon dioxide (nee), light use efficiency (lue, defined as gross ecosystem photosynthesis (gep)/photosynthetically active radiation (par)), and water use efficiency (wue, defined as gep/evapotranspiration (et)) to the changes in cloudiness. the five ecological sites included changbaishan temperate mixed forest (cbs), dinghushan subtropical evergreen broad-leaved forest (dhs), xishuangbanna tropical rainforest (xsbn), inner mongolia semi-arid leymus chinensis steppe (nmg), and haibei alpine frigid potentilla fruticosa shrub (hb). our analyses show that cloudy sky conditions with cloud index (k(t)) values between 0.4 and 0.6 increased nee, lue, and wue of the ecosystems at cbs, dhs, nmg and hb from june to august. the lue of tropical rainforest at xsbn was higher under cloudy than under clear sky conditions, but nee and wue did not decrease significantly under clear sky conditions from june to august. the increase in gep with increasing diffuse radiation received by ecosystems under cloudy skies was the main reason that caused the increases in lue and net carbon uptake in forest ecosystem at cbs, dhs, and alpine shrub ecosystem at hb, compared with clear skies. moreover, for the ecosystem at cbs, dhs, and hb, when sky condition became from clear to cloudy, gep increased and et decreased with decreasing vpd, leading to the increase in wue and nee under cloudy sky conditions. the decrease in re with decreasing temperature and increase in gep with decreasing vpd under cloudy skies led to the increase in lue. wue, and net carbon uptake of semi-arid steppe at nmg, compared to clear skies. these different responses among the five ecosystems are attributable to the differences in canopy characteristics and water conditions. from june to august, the peaks of the k(t) frequency distribution in temperate ecosystems (e.g., cbs, nmg, and hb) were larger than 0.5, but they were smaller than 0.4 in subtropical/tropical forest ecosystems (e.g., dhs and xsbn). these results suggest that the pattern of cloudiness during the years from 2003 to 2006 in the five ecosystems was not the best condition for their net carbon uptake. this study highlights the importance of cloudiness factor in the prediction of net carbon absorption in the asia monsoon region under climate change. (c) 2011 elsevier b.v. all rights reserved.
英文摘要	as a weather element, clouds can affect co(2) exchange between terrestrial ecosystems and the atmosphere by altering environmental conditions, such as solar radiation received on the ground surface, temperature, and moisture. based on the flux data measured at five typical ecosystems of china during mid-growing season (june-august) from 2003 to 2006, we analyzed the responses of net ecosystem exchange of carbon dioxide (nee), light use efficiency (lue, defined as gross ecosystem photosynthesis (gep)/photosynthetically active radiation (par)), and water use efficiency (wue, defined as gep/evapotranspiration (et)) to the changes in cloudiness. the five ecological sites included changbaishan temperate mixed forest (cbs), dinghushan subtropical evergreen broad-leaved forest (dhs), xishuangbanna tropical rainforest (xsbn), inner mongolia semi-arid leymus chinensis steppe (nmg), and haibei alpine frigid potentilla fruticosa shrub (hb). our analyses show that cloudy sky conditions with cloud index (k(t)) values between 0.4 and 0.6 increased nee, lue, and wue of the ecosystems at cbs, dhs, nmg and hb from june to august. the lue of tropical rainforest at xsbn was higher under cloudy than under clear sky conditions, but nee and wue did not decrease significantly under clear sky conditions from june to august. the increase in gep with increasing diffuse radiation received by ecosystems under cloudy skies was the main reason that caused the increases in lue and net carbon uptake in forest ecosystem at cbs, dhs, and alpine shrub ecosystem at hb, compared with clear skies. moreover, for the ecosystem at cbs, dhs, and hb, when sky condition became from clear to cloudy, gep increased and et decreased with decreasing vpd, leading to the increase in wue and nee under cloudy sky conditions. the decrease in re with decreasing temperature and increase in gep with decreasing vpd under cloudy skies led to the increase in lue. wue, and net carbon uptake of semi-arid steppe at nmg, compared to clear skies. these different responses among the five ecosystems are attributable to the differences in canopy characteristics and water conditions. from june to august, the peaks of the k(t) frequency distribution in temperate ecosystems (e.g., cbs, nmg, and hb) were larger than 0.5, but they were smaller than 0.4 in subtropical/tropical forest ecosystems (e.g., dhs and xsbn). these results suggest that the pattern of cloudiness during the years from 2003 to 2006 in the five ecosystems was not the best condition for their net carbon uptake. this study highlights the importance of cloudiness factor in the prediction of net carbon absorption in the asia monsoon region under climate change. (c) 2011 elsevier b.v. all rights reserved.
WOS标题词	science & technology ; life sciences & biomedicine ; physical sciences
类目[WOS]	agronomy ; forestry ; meteorology & atmospheric sciences
研究领域[WOS]	agriculture ; forestry ; meteorology & atmospheric sciences
关键词[WOS]	carbon-dioxide exchange ; leymus-chinensis steppe ; qinghai-tibetan plateau ; forest ecosystems ; environmental controls ; seasonal-variation ; vapor exchange ; inner-mongolia ; eastern china ; co2 exchange
收录类别	SCI
语种	英语
WOS记录号	WOS:000291283300005
公开日期	2011-12-13
内容类型	期刊论文
源URL	[http://ir.nwipb.ac.cn//handle/363003/1530]
专题	西北高原生物研究所_中国科学院西北高原生物研究所
作者单位	1.Chinese Acad Sci, Key Lab Ecosyst Network Observat & Modeling, Chinese Ecosyst Res Network, Inst Geog Sci & Nat Resources Res,Synth Res Ctr, Beijing 100101, Peoples R China 2.Chinese Acad Sci, Grad Univ, Beijing 100039, Peoples R China 3.Univ Tennessee, Inst Secure & Sustainable Environm, Knoxville, TN 37996 USA 4.Chinese Acad Sci, Inst Appl Ecol, Shenyang 110016, Peoples R China 5.Chinese Acad Sci, S China Bot Garden, Guangzhou 510650, Guangdong, Peoples R China 6.Chinese Acad Sci, Xishuangbanna Trop Bot Garden, Kunming 650223, Peoples R China 7.Chinese Acad Sci, NW Inst Plateau Biol, Xining 810001, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Mi,Yu, Gui-Rui,Zhuang, Jie,et al. Effects of cloudiness change on net ecosystem exchange, light use efficiency, and water use efficiency in typical ecosystems of China[J]. agricultural and forest meteorology,2011,151(7):803-816.
APA	Zhang, Mi.,Yu, Gui-Rui.,Zhuang, Jie.,Gentry, Randy.,Fu, Yu-Ling.,...&Li, Ying-Nian.(2011).Effects of cloudiness change on net ecosystem exchange, light use efficiency, and water use efficiency in typical ecosystems of China.agricultural and forest meteorology,151(7),803-816.
MLA	Zhang, Mi,et al."Effects of cloudiness change on net ecosystem exchange, light use efficiency, and water use efficiency in typical ecosystems of China".agricultural and forest meteorology 151.7(2011):803-816.