围栏封育对天山北坡草甸草原生态系统碳交换的影响

doi:10.17521/cjpe.2016.0049

摘要/Abstract

摘要：

草本层和大气间的碳交换及其对环境因子的响应是目前研究的热点。该研究通过静态箱法, 采用LI-840 CO₂/H₂O红外分析仪, 对新疆天山北坡草甸草原围封9年的样地和围栏外自然放牧生态系统碳交换进行监测, 分析了围栏内外生态系统碳交换的差异性、日变化、季节变化及其与环境因子的关系。结果表明: 围栏内生态系统碳交换高于围栏外, 围栏内外表现出明显的差异性; 围栏内外生态系统碳交换均存在明显的日变化和季节变化规律, 呈单峰曲线, 且在植物生长季峰形比较明显。在整个监测期间, 围栏内外生态系统CO₂净交换最小值分别为-7.62和-6.63 μmol·m ^-2·s ^-1, 生态系统呼吸最大值分别为8.55和7.04 μmol·m ^-2·s ^-1, 生态系统总初级生产力最大值分别为-14.66和-13.89 μmol·m ^-2·s ^-1。因围栏内植被得到保护, 草本植物生长茂盛, 光合作用强, 生态系统CO₂净交换较小, 同时有机碳的输入增强了生态系统呼吸。分析发现生态系统碳交换与气温和0-10 cm土壤温度显著相关, 与气温的相关性高于与0-10 cm土壤温度的相关性, 且围栏内禁牧处理相关性高于围栏外自然放牧草地; 土壤含水量与生态系统碳交换存在一定的相关性, 但其相关性略低于温度与生态系统碳交换的相关性。

关键词: 围栏封育, 草甸草原, 生态系统碳交换

Abstract:

Aims The carbon exchange between ecosystems and the atmosphere and its response to environmental factors is the focus of current research. The aim of this study was to examine the effects of fencing on ecosystem carbon exchange at meadow steppe in the northern slope of Tianshan Mountains.

Methods The static box method with a LI-840 CO₂/H₂O infrared analyzer was used to evaluate daily and seasonal changes of ecosystem carbon exchange and their relationship with environmental factors in the inside fence and outside fence after 9 years fencing.

Important findings We found the ecosystem carbon exchange inside the fence was significantly (p < 0.05) higher than that in outside the fence. The ecosystem carbon exchange had obvious daily and seasonal variation both in inside and outside the fence, which showed a unimodal curve during the plant growing season. The minimum net ecosystem CO₂ exchange (NEE) in the inside and outside of the fences were -7.62 and -6.63 μmol·m^-2·s^-1, respectively; the maximum ecosystem respiration (ER) were 8.55 and 7.04 μmol·m^-2·s^-1, respectively; and the maximum gross ecosystem productivity (GEP) were -14.66 and -13.89 μmol·m^-2·s^-1, respectively. Due to the protection of fence, the vegetation in the fence was flourished with higher photosynthesis, and thus resulted in lower NEE. Meanwhile, organic carbon input enhanced ecosystem respiration. Besides, the ecosystem carbon exchange significantly correlated with the air temperature and soil temperature of 0 to 10 cm depth, and the correlation with the air temperature was higher than soil temperature of 0 to 10 cm depth. Also, the correlation in the inside of the fence was higher than that in the outside of the fence. Ecosystem carbon exchange had correlation with soil water content, but the correlation was slightly lower than that with soil temperature.

Key words: fencing, meadow steppe, ecosystem carbon exchange

胡毅, 朱新萍, 贾宏涛, 韩东亮, 胡保安, 李典鹏. 围栏封育对天山北坡草甸草原生态系统碳交换的影响. 植物生态学报, 2018, 42(3): 372-381. DOI: 10.17521/cjpe.2016.0049

HU Yi, ZHU Xin-Ping, JIA Hong-Tao, HAN Dong-Liang, HU Bao-An, LI Dian-Peng. Effects of fencing on ecosystem carbon exchange at meadow steppe in the northern slope of the Tianshan Mountains. Chinese Journal of Plant Ecology, 2018, 42(3): 372-381. DOI: 10.17521/cjpe.2016.0049

导出引用管理器 EndNote|Ris|BibTeX

链接本文: https://www.plant-ecology.com/CN/10.17521/cjpe.2016.0049

https://www.plant-ecology.com/CN/Y2018/V42/I3/372

图/表 8

图1 围栏内外生态系统CO2净交换速率(NEE)日动态(A)和日平均值(B) (平均值±标准误差)。不同小写字母表示在0.05水平上差异显著。

Fig. 1 The daily dynamic (A) and daily average value (B) of the net ecosystem CO2 exchange (NEE) in inside and outside the fence (mean ± SE). The different lowercase letters represent significant differences at the 0.05 level.

图2 围栏内外生态系统呼吸(ER)日动态(A)和日平均值(B)(平均值±标准误差)。相同小写字母表示在0.05水平上差异不显著。

Fig. 2 The daily dynamic (A) and daily average value (B) of the ecosystem respiration (ER) in inside and outside the fence (mean ± SE). The same lowercase letters represent no significant differences at the 0.05 level.

图3 围栏内外生态系统总初级生产力(GEP)日动态(A)和日平均值(B) (平均值±标准误差)。相同小写字母表示在0.05水平上差异不显著。

Fig. 3 The daily dynamics (A) and daily average value (B) of the gross ecosystem productivity (GEP) in inside and outside the fence, respectively (mean ± SE). The same lowercase letters represent no significant differences at the 0.05 level.

图4 围栏内外生态系统CO2净交换速率(NEE)生长季动态特征(A)及NEE平均值(B)(平均值±标准误差)。不同小写字母表示在0.05水平上差异显著。

Fig. 4 The seasonal dynamic (A) and average value (B) of the the net ecosystem CO2 exchange (NEE) in inside and outside the fence, respectively (mean ± SE). The different lowercase letters represent significant differences at the 0.05 level.

图5 围栏内外生态系统呼吸(ER)的生长季动态(A)及ER平均值(B) (平均值±标准误差)。相同小写字母表示在0.05水平上差异不显著。

Fig. 5 The seasonal dynamic (A) and month average value (B) of the ecosystem respiration (ER) in inside and outside the fence, respectively (mean ± SE). The same lowercase letters represent no significant differences at the 0.05 level.

图6 围栏内外生态系统总初级生产力(GEP)生长季动态(A)及GEP平均值(B) (平均值±标准误差)。不同小写字母表示在0.05水平上差异显著。

Fig. 6 The seasonal dynamic (A) and average value (B) of the GEP in inside and outside the fence, respectively (mean ± SE). The different lowercase letters represent significant differences at the 0.05 level.

表1 围栏内外草甸草原生态系统CO2净交换速率(NEE)、生态系统呼吸(ER)、生态系统总初级生产力(GEP)与大气温度和0-10 cm土壤温度相关性

Table 1 The inside and outside the fence correlation coefficients between the net ecosystem CO2 exchange (NEE), ecosystem respiration (ER), gross ecosystem the productivity (GEP) and atmospheric temperature and 0-10 cm soil temperature in meadow steppe

	月份 Month	气温 Air temperature		土壤温度 Soil temperature
	月份 Month	围栏内 Inside the fence	围栏外 Outside the fence	围栏内 Inside the fence	围栏外 Outside the fence
NEE	4	-0.592^**	-0.487^*	0.501^*	0.602^**
	5	-0.572^**	-0.547^**	0.529^**	0.542^**
	6	-0.873^**	-0.841^**	0.349	0.109
	7	-0.685^**	-0.783^**	0.136	-0.227
	8	-0.867^**	-0.801^**	0.252	-0.089
	9	-0.850^**	-0.829^**	-0.347	-0.465^*
	10	-0.458^*	-0.471^*	0.384^*	0.440^*
ER	4	0.218	0.283	0.473^*	0.517^**
	5	0.620^**	0.767^**	0.353^*	-0.021
	6	0.483^*	0.298	0.354^*	0.423^*
	7	0.118	0.268	0.516^**	0.376^*
	8	0.392^*	0.548^**	0.752^**	0.567^**
	9	0.064	0.049	0.259	0.333
	10	-0.302	-0.308	0.279	0.508^*
GEP	4	-0.632^**	-0.572^**	0.501^*	0.624^**
	5	-0.677^**	-0.517^**	0.429^*	0.475^*
	6	-0.903^**	-0.839^**	0.204	-0.055
	7	-0.735^**	-0.805^**	0.147	-0.259
	8	-0.798^**	-0.828^**	0.116	-0.183
	9	-0.851^**	-0.769^**	-0.412^*	-0.465^*
	10	-0.598^**	-0.436^*	0.497^*	0.465^*

表2 围栏内外草甸草原生态系统CO2净交换速率(NEE)、生态系统呼吸(ER)、生态系统总初级生产力(GEP)与温度和土壤含水量的回归分析

Table 2 The regression analysis of the NEE (net ecosystem CO2 exchange), ER (ecosystem respiration), GEP (gross ecosystem the productivity) and temperature and soil water content in inside and outside the fence

因变量 Dependent variable	自变量 Independent variable	围栏内 Inside the fence			围栏外 Outside the fence
因变量 Dependent variable	自变量 Independent variable	回归方程 Regression equation	R²	p	回归方程 Regression equation	R²	p
NEE	气温 Air temperature	y = -0.299x + 4.722	0.863	0.002	y = -0.235x + 4.050	0.897	0.001
	土壤温度 Soil temperature	y = 0.118x²- 4.823x + 1.459	0.765	0.009	y = -0.178x + 2.738	0.907	0.001
	土壤含水量 Soil water content	y = 0.135x - 2.654	0.603	0.040	y = -0.002x²+ 0.198x - 1.459	0.493	0.078
ER	气温 Air temperature	y = 0.069e^0.197^x	0.720	0.012	y = 0.886e^0.066^x	0.810	0.005
	土壤温度 Soil temperature	y = 0.792e^0.026^x	0.690	0.017	y = 0.446e^0.580^x	0.706	0.015
	土壤含水量 Soil water content	y = -0.015x²+ 4.198x - 5.459	0.633	0.045	y = 10.348e^-0.067^x	0.460	0.094
GEP	气温 Air temperature	y = -0.767x + 8.517	0.899	0.001	y = -0.650x + 7.244	0.789	0.008
	土壤温度 Soil temperature	y = -0.558x + 4.313	0.929	0.000	y = -0.515x + 3.895	0.871	0.002
	土壤含水量 Soil water content	y = 0.294x - 9.289	0.453	0.097	y = 0.253x - 7.831	0.353	0.160

参考文献 39

[1]	Bachman S, Heisler-White JL, Pendall E, Williams D, Morgan JA, Newcomb J ( 2010). Elevated carbon dioxide alters impacts of precipitation pulses on ecosystem photosynthesis and respiration in a semi-arid grassland. Oecologia, 62, 791-802. DOI URL PMID
[2]	Baldocchi D ( 1997). Measuring and modeling carbon dioxide and water vapor exchange over a temperate broad-leafed forest during the 1985 summer drought. Plant, Cell & Environment, 20, 1108-1122. DOI URL
[3]	Black TA, Hartog GD, Neumann HH, Blanken PD, Yang PC, Russell C, Nesic Z, Lee X, Chen SG, Staebler R, Novak MD ( 1996). Annual cycles of water vapour and carbon dioxide fluxes in and above a boreal aspen forest. Global Change Biology, 2, 219-229. DOI URL
[4]	Chen J, Shi WY, Cao JJ ( 2014). Effects of grazing on ecosystem CO2 exchange in a meadow grassland on the Tibetan Plateau during the growing season. Environmental Management, 55, 347-359. DOI URL PMID
[5]	Chen QS, Li LH, Han XG, Yan ZD, Wang YF, Zhang Y, Yuan ZY, Tang F ( 2003). Responses of soil respiration to temperature in eleven communities in Xilingol grassland, Inner Mongolia. Acta Phytoecologica Sinica, 27, 441-447. DOI URL
	陈全胜, 李凌浩, 韩兴国, 阎志丹, 王艳芬, 张焱, 袁志友, 唐芳 ( 2003). 温带草原11个植物群落夏秋土壤呼吸对气温变化的响应. 植物生态学报, 27, 441-447. DOI URL
[6]	Dong G ( 2011). Carbon and Water Fluxes and Water Use Efficiency of the Songnen Meadow Steppe in North East China. PhD dissertation, Northeast Normal University, Changchun.
	董刚 ( 2011). 中国东北松嫩草甸草原碳水通量及水分利用效率研究. 博士学位论文, 东北师范大学, 长春.
[7]	Duan XN, Wang XK, Feng ZZ, Ouyang ZY ( 2005). Study of net ecosystem exchange for seedling stage of spring wheat ecosystem in Hetao irrigation district, Inner Mongolia. Journal of Environmental Science, 25, 166-171.
	段晓男, 王效科, 冯兆忠, 欧阳志云 ( 2005). 内蒙古河套灌区春小麦苗期生态系统CO2通量变化研究. 环境科学学报, 25, 166-171.
[8]	Fan LL, Xie JP, Ma J, Wang ZY, Zhao HM ( 2013). Variation characteristics of herb layer carbon flux and soil respiration in southern edge of Jungggar Basin, Northwest China. Chinese Journal of Ecology, 32, 2567-2573.
	范连连, 谢继萍, 马健, 王忠媛, 赵红梅 ( 2013). 准噶尔盆地南缘草本层碳通量及土壤呼吸的变化特征. 生态学杂志, 32, 2567-2573.
[9]	Flanagan LB, Johnson BG ( 2005). Interacting effects of temperature, soil moisture and plant biomass production on ecosystem respiration in a northern temperate grassland. Agricultural and Forest Meteorology, 130, 237-253. DOI URL
[10]	Fu YL, Yu GR, Wang YF, Li ZQ, Hao YB ( 2006). Effect of water stress on ecosystem photosynthesis and respiration of a Leymus chinensis steppe in Inner Mongolia. Science in China: Series D, Earth Sciences, 36(Suppl. I), 183-193.
	伏玉玲, 于贵瑞, 王艳芬, 李正泉, 郝彦宾 ( 2006). 水分胁迫对内蒙古羊草草原生态系统光合和呼吸作用的影响. 中国科学: D辑地球科学, 36(增刊I), 183-193.
[11]	Gao CD, Sun XY, Zhang L, Li ZG, A L ( 2009). Changing characteristics of CO2 flux from the interface of soil-atmosphere at arid area in north temperate. Journal of Beijing Forestry University, 31(6), 32-38.
	高程达, 孙向阳, 张林, 李志刚, 阿拉塔 ( 2009). 北温带干旱地区土壤-大气界面CO2通量的变化特征. 北京林业大学学报, 31(6), 32-38.
[12]	Guo MY, Chao KL, You JC, Xu LJ, Wang LJ, Jia SJ, Xin XP ( 2012). Soil microbial characteristic and soil respiration in grassland under different use patterns. Acta Agrestia Sinica, 20, 42-48. DOI URL
	郭明英, 朝克图, 尤金成, 徐丽君, 王丽娟, 贾淑杰, 辛晓平 ( 2012). 不同利用方式下草地土壤微生物及土壤呼吸特性. 草地学报, 20, 42-48. DOI URL
[13]	Houghton RA ( 2003). Revised estimates of the annual net flux of carbon to the atmosphere from changes in land use and land management 1850-2000. Tellus Series B—Chemical and Physical Meteorology, 55, 378-390.
[14]	Hu Y, Zhu XP, Han DL, Jia HT, Hu BA, Li DP ( 2016). Effects of fencing on soil respiration rates in the meadow steppes in the northern slope of the Tianshan Mountains. Acta Ecologica Sinica, 36, 6379-6386.
	胡毅, 朱新萍, 韩东亮, 贾宏涛, 胡保安, 李典鹏 ( 2016). 围栏封育对天山北坡草甸草原土壤呼吸的影响. 生态学报, 36, 6379-6386.
[15]	Jia BR, Zhou GS, Wang FY, Wang YH ( 2005). Soil respiration and its influencing factors at grazing and fenced typical Leymus chinensis steppe, Nei Monggol. Environment Science, 26(6), 1-7.
	贾丙瑞, 周广胜, 王风玉, 王玉辉 ( 2005). 放牧与围栏羊草草原土壤呼吸作用及其影响因子. 环境科学, 26(6), 1-7.
[16]	Jia BR, Zhou GS, Wang FY, Wang YH, Weng EH ( 2007). Effects of grazing on soil respiration of Leymus chinensis steppe. Climatic Change, 82, 211-223.
[17]	Kato T, Tang YH, Gu S, Hirota M, Du MY, Li YN, Zhao XQ ( 2006). Temperature and biomass influences on interannual changes in CO2 exchange in an alpine meadow on the Qinghai-Tibetan Plateau. Global Change Biology, 12, 1285-1298. DOI URL
[18]	Law BE, Falge E, Gu L, Baldocchi DD, Bakwin P, Berbigier P, Davis K, Dolman AJ, Falk M, Fuentes JD, Goldstein A, Granier A, Grelle A, Hollinger D, Janssens IA, Jarvis P, Jensen NO, Katul G, Mahli Y, Matteucci G, Meyers T, Monson R, Munger W, Oechel W, Olson R, Pilegaard K, Paw KT, Thorgeirsson H, Valentini R, Verma S, Vesala T, Wilson K, Wofsy S ( 2002). Environmental controls over carbon dioxide and water vapor exchange of terrestrial vegetation. Agricultural and Forest Meteorology, 113, 97-120. DOI URL
[19]	Li XR, Ma FY, Xiao HL, Wang XP, Kim KC ( 2004). Long term effects of revegetation on soil water content of sand dunes in arid region of Northern China. Journal of Arid Environments, 57, 1-16. DOI URL
[20]	Luo CY, Bao XY, Wang SP, Zhu XX, Cui SJ, Zhang ZH, Xu BB, Niu HS, Zhao L, Zhao XQ ( 2015). Impacts of seasonal grazing on net ecosystem carbon exchange in alpine meadow on the Tibetan Plateau. Plant and Soil, 396, 381-395. DOI URL
[21]	Ma J, Tang HP ( 2011). Variations of soil respiration rate and its temperature sensitivity among different land use types in the agro-pastoral ecotone of Inner Mongolia. Chinese Journal of Plant Ecology, 35, 167-175. DOI URL
	马骏, 唐海萍 ( 2011). 内蒙古农牧交错区不同土地利用方式下土壤呼吸速率及其温度敏感性变化. 植物生态学报, 35, 167-175. DOI URL
[22]	Mcfadden JP, Eugster W, Chapin FS ( 2003). A regional study of the controls on water vapor and CO2 exchange in arctic tundra. Ecology, 84, 2762-2776. DOI URL
[23]	Oberbauer SF, Tweedie CE, Welker JM Fahnestock JT, Henry GHR, Webber PJ, Hollister RD, Waiker MD, Kuchy A, Elmore E, Starr G ( 2007). Tundra CO2 fluxes in response to experimental warming across latitudinal and moisture gradients. Ecological Monographs, 77, 221-238. DOI URL
[24]	Sharkhuu A, Plante AF, Enkhmandal O, Gonneau C, Casper BB, Boldgiv B, Petraitis PS ( 2016). Soil and ecosystem respiration responses to grazing, watering and experimental warming chamber treatments across topographical gradients in northern Mongolia. Geoderma, 269, 91-98. DOI URL PMID
[25]	Sun DC, Li YL, Zhao XY, Zuo XA, Mao W ( 2015). Effects of enclosure and grazing on carbon and water fluxes of sandy grassland. Chinese Journal of Plant Ecology, 39, 565-576.
	孙殿超, 李玉霖, 赵学勇, 左小安, 毛伟 ( 2015). 围封和放牧对沙质草地碳水通量的影响. 植物生态学报, 39, 565-576.
[26]	Suyker AE, Verman SB, Burba GG ( 2003). Interannual variability in net CO2 exchange of a native tall grass prairie. Global Change Biology, 9, 255-265. DOI URL
[27]	Wu LB, Gu S, Zhao L, Xu SX, Zhou HK, Feng C, Xu WX, Li YN, Zhao XQ, Tang YH ( 2010). Variation in net CO2 exchange, gross primary production and its affecting factors in the planted pasture ecosystem in Sanjiangyuan Region of the Qinghai-Tibetan Plateau of China. Chinese Journal of Plant Ecology, 34, 770-780. DOI URL
	吴力博, 古松, 赵亮, 徐世晓, 周华坤, 冯超, 徐维新, 李英年, 赵新全, 唐艳鸿 ( 2010). 三江源地区人工草地的生态系统CO2净交换、总初级生产力及其影响因子. 植物生态学报, 34, 770-780. DOI URL
[28]	Xu P ( 1993). Grassland Resources and Its Utilization in Xinjiang. Science and Technology and Health Press, ürümqi.
	许鹏 ( 1993). 新疆草地资源及其利用. 科技卫生出版社, 乌鲁木齐.
[29]	Xu P ( 1998). The Desert Grassland and Water Salt Plant System and Optimized Ecological Model in Xinjiang. Science Press, Beijing. 9-11.
	许鹏 ( 1998). 新疆荒漠区草地与水盐植物系统及优化生态模式. 科学出版社, 北京. 9-11.
[30]	Yang LL, Gong JR, Wang YH, Liu M, Luo QP, Xu S, Pan Y, Zhai ZW ( 2016). Effects of grazing intensity and grazing exclusion on litter decomposition in the temperate steppe of Nei Mongol, China. Chinese Journal of Plant Ecology, 40, 748-759.
	杨丽丽, 龚吉蕊, 王忆慧, 刘敏, 罗亲普, 徐沙, 潘琰, 翟占伟 ( 2016). 内蒙古温带草原不同放牧强度和围栏封育对凋落物分解的影响. 植物生态学报, 40, 748-759.
[31]	Yang Y, Han GD, Li YH, Chen ZF, Wang CJ ( 2012). Response of soil respiration to grazing intensity, water contents, and temperature of soil indifferent grasslands of Inner Mongolia. Acta Prataculturae Sinica, 21(6), 8-14.
	杨阳, 韩国栋, 李元恒, 陈志芳, 王成杰 ( 2012). 内蒙古不同草原类型土壤呼吸对放牧强度及水热因子的响应. 草业学报, 21(6), 8-14.
[32]	Ye M, Xu HL, Wang XP, Li XX ( 2006). An assessment of the value and valuation of the grassland ecosystem in Xinjiang. Acta Prataculturae Sinica, 15, 122-128. DOI URL
	叶茂, 徐海量, 王小平, 李祥心 ( 2006). 新疆草地生态系统服务功能与价值初步评价. 草业学报, 15, 122-128. DOI URL
[33]	Yin GM, Zhang YJ, Wang MY, Xue YL, Zhao HP ( 2014). Influence of short-term enclosure on characteristics of community and species diversity on meadow steppe. Chinese Journal of Grassland, 36(3), 61-66. DOI URL
	殷国梅, 张英俊, 王明莹, 薛艳林, 赵和平 ( 2014). 短期围封对草甸草原群落特征与物种多样性的影响. 中国草地学报, 36(3), 61-66. DOI URL
[34]	Yu GR, Sun XM ( 2008). Carbon Flux Observation Technology and Temporal and Spatial Characteristics of Terrestrial Ecosystems in China. Science Press, Beijing.
	于贵瑞, 孙晓敏 ( 2008). 中国陆地生态系统碳通量观测技术及时空变化特征. 科学出版社, 北京.
[35]	Yu GR, Wen XF, Li QK, Zhang LM, Ren CY, Liu YF, Guan DX ( 2005). Seasonal patterns of ecosystem respiration and environmental response characteristics of China subtropical and temperate typical forests. Science in China: Series D, Earth Sciences, 34(Suppl.), 84-94.
	于贵瑞, 温学发, 李庆康, 张雷明, 任传友, 刘允芬, 关德新 ( 2005). 中国亚热带和温带典型森林生态系统呼吸的季节模式及环境响应特征. 中国科学: D辑, 34(增刊), 84-94.
[36]	Zhang WH, Guan SY, Li YJ ( 2000). Effect of grazing capacity on water content, nutrient and biomass of steppe soil. Journal of Arid Land Resources and Environment, 14(4), 62-65.
	张伟华, 关世英, 李跃进 ( 2000). 不同牧压强度对草原土壤水分、养分及其地上生物量的影响. 干旱区资源与环境, 14(4), 62-65.
[37]	Zhang WL, Chen SP, Miao HX, Lin GH ( 2008). Effects on carbon flux of conversion of grassland steppe to cropland in China. Journal of Plant Ecology (Chinese Version), 32, 1301-1311. DOI URL
	张文丽, 陈世苹, 苗海霞, 林光辉 ( 2008). 开垦对克氏针茅草地生态系统碳通量的影响. 植物生态学报, 32, 1301-1311. DOI URL
[38]	Zhang YQ, Chen YJ, Liu CM, Yu Q, Sun HY, Jia JS, Tang CY, Kondoh A ( 2002). Measurement and analysis of water, heat and CO2 flux from a farmland in the North China Plain. Acta Geographica Sinica, 57, 333-342. DOI URL
	张永强, 沈彦俊, 刘昌明, 于强, 孙宏永, 贾金生, 唐常源 , Kondoh A ( 2002). 华北平原典型农田水、热与CO2通量的测定. 地理学报, 57, 333-342. DOI URL
[39]	Zuo XA, Zhao HL, Zhao XY, Guo YR, Zhang TH, Mao W, Su N, Feng J ( 2009). Species diversity of degraded vegetation in different age restorations in Horqin Sandy Land, Northern China. Acta Prataculturae Sinica, 18(4), 9-16. DOI URL
	左小安, 赵哈林, 赵学勇, 郭轶瑞, 张铜会, 毛伟, 苏娜, 冯静 ( 2009). 科尔沁沙地不同恢复年限退化植被的物种多样性. 草业学报, 18(4), 9-16. DOI URL