大气
  <strong>CO<sub>2</sub></strong>浓度增加对中国区域植被蒸腾的影响

doi:10.11867/j.issn.1001-8166.2021.078

近几十年来，人类活动带来的化石燃料燃烧和工业过程引起了全球大气CO₂浓度的显著增长，带来了一系列生态和环境问题，其中对地表蒸散发的影响就是一个重要方面。地表蒸散发及其分量植被蒸腾是能量和水量平衡的重要组分，直接影响着陆气相互作用和水循环系统。由于大气CO₂浓度增加可通过减小叶片气孔导度从而抑制植被蒸腾，为量化这一影响，基于碳水耦合的蒸散发模型PML-V2和CMIP6的大气CO₂浓度时空序列驱动数据，分别进行了考虑和不考虑大气CO₂浓度逐年增加情况下的2组植被蒸腾模拟试验。通过对比2组结果分析了2001—2014年大气CO₂浓度增加对中国区域植被蒸腾的影响。研究结果显示，在季节上，夏季大气CO₂浓度增加对植被蒸腾的抑制作用最小，冬季最大；在数量级上，2001—2014年大气CO₂浓度引起植被蒸腾变化在0~5%；不同生态系统比较而言，森林、耕地和灌丛生态系统受CO₂浓度增加引起植被蒸腾的减小量较大，14年间减小量为15~20 mm/a，而草地下降最小，约5 mm/a；在空间上，我国中东部受影响最大；CO₂浓度引起植被蒸腾变化最敏感的区域是我国东南部地区。

关键词: 大气CO₂浓度, 植被蒸腾, PML-V2模型

In recent decades， a great increase of atmospheric CO₂ concentration has （［CO₂］） occurred due to fossil fuel combustion and industrialization， which has caused a series of ecological and environmental issues. One of the effects of the increase of ［CO₂］ is on evapotranspiration （ET）. ET is a component of surface energy balance and water balance， therefore， its change would influence the exchange between surface and atmosphere and water cycle directly. On the basis of a water-carbon coupled model named PML-V2 and the CMIP6 ［CO₂］ datasets， this study estimated two sets of vegetation transpiration （Ec） from 2001 to 2014. One simulation is static： the constant ［CO₂］ concentration in 2001 is fixed as input during the simulation from 2001 to 2014. The other was dynamic： time-varying ［CO₂］ was used during the simulation from 2001 to 2014. By comparing the two sets of Ec， the effects of ［CO₂］ on Ec were explored. The results showed that the reduction in Ec due to the increase of ［CO₂］ was smallest in summer and is largest in winter. From 2001 to 2014， this reduction is 0~5%. The largest effect occurred in the eastern and in the central areas of China. For ecosystems of forest， wetland， cropland and shrubland/savanna， the reduction of Ec due to the increase of ［CO₂］ is 15~20 mm/a till 2014. For grassland， the reduction is 5 mm/a. The sensitivity of the effects of the increase of ［CO₂］ on Ec to arid index， precipitation and air temperature indicated that Ec was the most sensitive to ［CO₂］ in the southeast of China.

Key words: Atmospheric CO₂ concentration, Vegetation transpiration, PML-V2 model

中图分类号:

P426.2

图1 2001—2014年大气CO₂浓度多年平均值（a）和年季变化（b）

Fig. 1 Multi-year average （a） of atmospheric CO₂ concentration and its seasonal change （b）（2001-2014）

图2 4个季度大气CO₂浓度2014 年与2001 年差值的空间分布
冬季：当年12月至次年2 月；春季：3~5 月；夏季：6~8 月；秋季：9~11 月

Fig. 2 Difference of atmospheric CO₂ concentration for four seasons between 2001 and 2014
Winter：from December to February next year；Spring：from March to May；Summer：from June to August；Autumn：from September to November

图3 大气CO₂浓度增加引起的2001—2014年不同季节植被蒸腾量相对变化百分率
相对变化百分率=CO ₂浓度增加引起的变化量/2001年值；白色区域表示无植被蒸腾

Fig. 3 Relative change percent of transpiration for four seasons due to the increase of atmospheric CO₂ concentration
Relative change percent = change of transpiration due to CO ₂ increase /transpiration in 2001； No transpiration in white areas

图4 2001—2014年大气CO₂浓度变化对中国及不同生态系统年植被蒸腾量的影响
差值=固定CO ₂的植被蒸腾-变化CO ₂的植被蒸腾

Fig. 4 Effects of atmospheric CO₂ concentration on transpiration for different ecosystems over China during 2001-2014
Difference=transpiration in constant CO ₂-transpiration in varied CO ₂

图5 2014年MODIS中国区域土地利用/覆盖分类
森林：常绿阔叶/针叶林、落叶阔叶/针叶林、混交林；灌从：郁闭/开放灌丛、多树/稀树草原；草原：草原；耕地：作物、作物和自然植被镶嵌体

Fig. 5 Land use/cover classifications based on MODIS product in 2014
Forests： Evergreen needleleaf / Broadleaf forest， deciduous needleleaf / broadleaf forest and mixed forest； Shrublands： closed / open shrublands， woody savannas， savannas； Grasslands： grassland； Agricural land： croplands， cropland / natural vegetation mosaics

图6 2001—2014年CO₂浓度引起植被蒸腾变化（植被蒸腾/ΔCO₂浓度）随干燥指数、年降雨量和年平均气温的变化Fig. 6 Transpiration change due to the increase of atmospheric CO₂ concentration （transpiration/ΔCO₂） with the change of arid index， annual precipitation and annual air temperature during 2001-2014

图7 2001—2014年平均干燥指数空间分布图

Fig. 7 Spatial distribution of multi-year average of arid index during 2001-2014

1	PACHAURI R K， ALLEN M R， BARROS V R， et al. Climate change 2014： synthesis report， contribution of working groups I， II and III to the fifth assessment report of the Intergovernmental Panel on Climate Change （IPCC）［M］. Cambridge： Cambridge University Press， 2014.
2	LEI Liping， ZHONG Hui， HE Zhonghua， et al. Assessment of atmospheric CO₂ concentration enhancement from anthropogenic emissions based on satellite observations ［J］. Science Bulletin， 2017，62（25）：2 941-2 950.
	雷莉萍，钟惠，贺忠华，等.人为排放所引起大气CO₂浓度变化的卫星遥感观测评估［J］. 科学通报， 2017，62（25）：2 941-2 950.
3	YIN Feihu， LI Xiaolan， DONG Yunshe， et al. Effect of elevated CO₂ on ecosystem and C-N coupling in arid and semi-arid region ［J］. Advances in Earth Science， 2011，26（2）：235-244.
	尹飞虎，李晓兰，董云社，等. 干旱半干旱区CO₂浓度升高对生态系统的影响及碳氮耦合研究进展［J］. 地球科学进展， 2011，26（2）：235-244.
4	CHEN Jingming， JU Weimin， CIAIS P， et al. Vegetation structural change since 1981 significantly enhanced the terrestrial carbon sink［J］. Nature Communication 2019， 10. DOI： 10.1038/S41467-019-12257-8. doi: 10.1038/S41467-019-12257-8
5	HOEK VAN DIJKE A J， MALLICK K， SCHLERF M， et al. Examining the link between vegetation leaf area and land-atmosphere exchange of water， energy， and carbon fluxes using FLUXNET data［J］. Biogeosciences， 2020， 17： 4 443-4 457.
6	MANKIN J S， SEAGER R， SMERDON J E，et al. Mid-latitude freshwater availability reduced by projected vegetation responses to climate change［J］. Nature Geoscience， 2019， 12： 983-988.
7	ELIZABETH A A， STEPHEN P L. What have we learned from 15 years of Free‐Air CO₂ Enrichment （FACE）？ a meta‐analytic review of the responses of photosynthesis， canopy properties and plant production to rising CO₂ ［J］. New Phytologist， 2004， 165（2）： 351-372.
8	LEAKEY A D B， AINSWORTH E A， BERNACCHI C J， et al. Elevated CO₂ effects on plant carbon， nitrogen， and water relations： six important lessons from FACE［J］. Journal of Experimental Botany， 2009， 60（10）： 2 859-2 876.
9	KELLNER J， MULTSCH S， HOUSKA T， et al. A coupled hydrological-plant growth model for simulating the effect of elevated CO₂ on a temperate grassland［J］. Agricultural and Forest Meteorology， 2017， 246： 42-50.
10	YANG Yuting， RODERICK M L， ZHANG Shulei， et al. Hydrologic implications of vegetation response to elevated CO₂ in climate projections ［J］. Nature Climate Change， 2019， 9： 44-48.
11	RODERICK M L， GREVE P， FARQUHAR G D. On the assessment of aridity with changes in atmospheric CO₂ ［J］. Water Resource Research， 2015， 51： 5 450-5 463.
12	DONOHUE R J， RODERICK M L， MCVICAR T R， et al. Impact of CO₂ fertilization on maximum foliage cover across the globe's warm， arid environments［J］. Geophysical Research Letters， 2013， 40： 3 031-3 035.
13	ZHAO Meng， GERUO A， ZHANG Jien， et al. Ecological restoration impact on total terrestrial water storage［J］. Nature Sustainability， 2020， 4（1）： 56-62.
14	LI Congcong， ZHANG Yongqiang， SHEN Yanjun， et al. Decadal water storage decrease driven by vegetation changes in the Yellow River Basin［J］. Science Bulletin， 2020，65（22）： 1 859-1 861.
15	DERYNG D， ELLIOTT J， FOLBERTH C， et al. Regional disparities in the beneficial effects of rising CO₂ concentrations on crop water productivity ［J］. Nature Climate Change， 2016， 6： 786-790.
16	TIAN Jing， ZHANG Yongqiang. Detecting changes in irrigation water requirement in Central Asia under CO₂ fertilization and land use changes ［J］. Journal of Hydrology， 2020， 583. DOI：10.1016/j.jhydrol.2019.124315. doi: 10.1016/j.jhydrol.2019.124315
17	MEINSHAUSEN M， VOGEL E， NAUELS A， et al. Historical greenhouse gas concentrations for climate modelling （CMIP6）［J］. Geoscientific Model Development， 2017， 10： 2 057-2 116.
18	ZHAO Maosheng， HEINSCH F A， NEMANI R R， et al. Improvements of the modis terrestrial gross and net primary production global data set ［J］. Remote Sensing of Environment， 2004， 95（2）： 164-176.
19	ERSHADI A， MCCABE M F， EVANS J P， et al. Effects of spatial aggregation on the multi-scale estimation of evapotranspiration ［J］. Remote Sensing of Environment， 2013， 131： 51-62.
20	MYNENI R B， HOFFMAN S， KNYAZIKHIN Y， et al. Global products of vegetation leaf area and fraction absorbed PAR from year one of MODIS data ［J］. Remote Sensing of Environment， 2002， 83（1/2）： 214-231.
21	SCHAAF C B， GAO F， STRAHLER A H， et al. First operational BRDF， Albedo and Nadir reflectance products from MODIS ［J］. Remote Sensing of Environment， 2002， 83： 135-148.
22	FRIEDL M A， MCIVER D K， HODGES J， et al. Global land cover mapping from MODIS： algorithms and early results ［J］. Remote Sensing of Environment， 2002， 83（1）：287-302.
23	HULLEY G C， HOOK S J， ABBOTT E， et al. The ASTER Global Emissivity Dataset （ASTER GED）： mapping Earth's emissivity at 100 meter spatial scale ［J］. Geophysical Research Letters， 2015， 42： 7 966-7 976.
24	GAN Rong， ZHANG Yongqiang， SHI Hao， et al. Use of satellite leaf area index estimating evapotranspiration and gross assimilation for Australian ecosystems ［J］. Ecohydrology， 2018， 11. DOI： 10.1002/eco.1974. doi: 10.1002/eco.1974
25	ZHANG Yongqiang， KONG Dongdong， GAN Rong， et al. Coupled estimation of 500 m and 8-day resolution global evapotranspiration and gross primary production in 2002-2017 ［J］. Remote Sensing of Environment， 2019， 222： 165-182.
26	MCDERMID S S， COOK B I， DE KAUWE M G， et al. Disentangling the regional climate impact of competing vegetation responses to elevated atmospheric CO₂ ［J］. Journal of Geophysical Research： Atmospheres， 2021， 126. DOI： 10.1029/2020JD034108. doi: 10.1029/2020JD034108
27	SWANN A S， HOFFMAN F M， KOVEN C D， et al. Plant responses to increasing CO₂ reduce estimates of climate impacts on drought severity ［J］. Proceedings of the National Academy of the Sciences of the United States of America， 2016， 113（36）：10 019-10 024.
28	UEYAMA M， ICHII K， KOBAYASHI H， et al. Inferring CO₂ fertilization effect based on global monitoring land-atmosphere exchange with a theoretical model ［J］. Environmental Research Letters， 2020， 15. DOI： 10.1088/1748-9326/ab79e5. doi: 10.1088/1748-9326/ab79e5
29	UKKOLA A M， PRENTICE I C， KEENAN T F， et al. Reduced streamflow in water-stressed climates consistent with CO₂ effects on vegetation ［J］. Nature Climate Change， 2015， 6： 75-78.

[1]	陈骏,杨杰东,李春雷. 大陆风化与全球气候变化[J]. 地球科学进展, 2001, 16(3): 399-405.

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摘要

Effects of Atmospheric CO 2 Concentration on Vegetation Transpiration over China

Effects of Atmospheric CO ₂ Concentration on Vegetation Transpiration over China