1 Brown G P. 1995. Arable land loss in rural china: policy and implementation in Jiangsu province. Asian Survey , 35(10): 922-940.
2 Dai L M, Wang X L. 2000. Indicators to assess the ecological effect of the 3 North Windbread system. World Forestry Research , 13(2): 47-50. (in Chinese)
3 Easterling W E, Hays C J, Easterling M K, et al. 1997. Modelling the effect of shelterbelts on maize productivity under climate change: An application of the EPIC model. Agriculture Ecosystems and Environment , 61 (2-3): 163-176.
4 FAO. 2009. The state of food insecurity in the world. Rome.
5 Fei Y H, Miao J X, Zhang Z J, et al . 2009. Analysis on evolution of groundwater depression cones and its leading factors in North China Plain. Resources Science , 31(3): 394-399. (in Chinese)
6 Fu B J, Guo X D, Chen L D. 2001. Land use changes and soil nutrient changes: A case study in Zunhua County, Hebei Province. Acta Ecologica Sinica , 21(6): 926-931. (in Chinese)
7 Haywood J D. 1994. Early growth reduction in short rotation loblolly and slash pine in central Louisiana. Southern Journal of Applied Forestry , 18(1): 35-39.
8 Heilig G K, Fischer G, Velthuizen H V . 2000. Can China feed itself? An analysis of China's food prospects with special reference to water resources. International Journal of Sustainable Development and World Ecology , 7(3): 153-172.
9 He K N, Tian Y, Shi C Q, et al . 2003. The suitable soil moisture condition for forest growth in catchment afforestation in semi-arid region on loess plateaus. Scientia Silvae Sinicae , 39(1): 10-16. (in Chinese)
10 Hou Q, Shen J G. 2001. Study on root development characteristics of spring maize and its relationships with canopy growth. Acta Ecologica Sinica , 21(9): 1536-1542. (in Chinese)
11 Huang J K, Zhu L F, Deng X Z. 2007. Regional differences of China construction land expansion and its influence factors. Science in China (Series D: Earth Sciences) , 37(9): 1235-1241. (in Chinese)
12 International Center for Agroforestry I. 2003. Rising preference for eucalyptus poses dilemma in eastern Africa. Policy Brief. http://www.relma. org/pdfs/Eucalyptus_policy_brief.pdf.
13 Li B F. 2010. Study on Impact of the biofuel development on food security and energy security. Ecological Economy , (3): 41-42. (in Chinese)
14 Li C H, Tang L S. 2013. Long-term effect of fertilization application on soil organic carbon and its fractions in soil profiles of an oasis farmland. Arid Land Geography , 36(4): 637-644. (in Chinese)
15 Li F, Meng P, Fu D, et al. 2008. Light distribution, photosynthetic rate and yield in a paulownia-wheat intercropping system in China. Agroforestry Systems, 74(2): 163-172.
16 Liu J M, An S Q, Liao R W, et al. 2009. Temporal variation and spatial distribution of the root system of corn in a soil profile. Chinese Journal of Eco-Agriculture , 17(3): 517-521. (in Chinese)
17 Liu X H. 2005. Thoughts on the “poplar expansion and cropland shrinkage” phenomenon in Huang-Huai-Hai plain. Crops , (6): 1-3. (in Chinese)
18 Liao X Y, Chen Z J, Liu S Q, et al . 2005. Effects of land use types on soil fertility in small watershed in the Three Gorges Reservoir. Ecology and Environment , 14(1): 99-101. (in Chinese)
19 Li Y Z, Xie Y H, Li F, et al. 2014. Effects of poplar plantations on soil physical and chemical characteristics in Dongting Lake wetlands. Research of Agricultural Modernization , 35(2): 234-239. (in Chinese)
20 Longhurst R. 1987. Household food security, tree planting and the poor: the case of Gujarat. Social Forestry Network Paper 5d , London.
21 Lungo A D, Vuorinen P, Carle J. 2001. Preliminary analysis of global trends in forest plantation development, 1980-2000. Forestry Division, FAO, Rome.
22 Ma X Q, Fan S H, Chen S S, et al. 2003. Study on biomass productivity of Chinese fir plantations after successive planting. Scientia Silvae Sinicae , 29(2): 78-83. (in Chinese)
23 Motavalli P P, Discekici H, Kuhn J. 2000. The impact of land clearing and agricultural practices on soil organic C fractions and CO 2 efflux in the Northern Guam aquifer. Agriculture, Ecosystems & Environment , 79(1): 17-27.
24 Nawir A A, Kassa H, Sandewall M, et al. 2007. Stimulating smallholder tree planting-lessons from Africa and Asia. Unasylva , 58(228): 53-58.
25 Nuberg I K. 1998. Effect of shelter on temperate crops: a review to define research for Australian conditions. Agroforestry Systems , 41(1): 3-34.
26 Pang J L, Zhang W Q, Huang C C, et al . 2010. The Influence of land use change on soil development and over the loess tablelands in the Northern Weihe River Basin, China. Acta Geographica Sinica , 65(7): 789- 800. (in Chinese)
27 Pretty J N, Morison J I L, Hine R E. 2003. Reducing food poverty by increasing agricultural sustainability in developing countries. Agriculture, Ecosystems & Environment , 95(1): 217-234.
28 Richter D D, Markewitz D, Trumbore S E, et al. 1999. Rapid accumulation and turnover of soil carbon in a reestablishing forest. Nature, 400 (6739): 56-58.
29 Scott D F, Lesch W. 1997. Streamflow responses to afforestation with Eucalyptus grandis and Pinus patula and to felling in the Mokobulaan experimental catchments, South Africa. Journal of Hydrology , 199(3-4): 360-377.
30 Shi Z H, Chen L D, Hao J P, et al . 2008. The effects of land use change on environmental quality in the red soil hilly region, China: A case study in Xianning county. Environmental Monitoring and Assessment , 150(1-4): 295-306.
31 Solomon D, Fritzsche F, Tekalign M, et al . 2002. Soil organic matter composition in the subhumid Ethiopian highlands as influenced by deforestation and agricultural management. Soil Science Society of America Journal , 66(1): 68-82.
32 Sun C L, Zhu Z X, Wang Z, et al. 1995. Study on the soil degradation of the poplar plantation and the technique to preserve and increase soil fertility. Scientia Silvae Sinicae , 3(6): 506-511. (in Chinese)
33 Sun Y F, Qi C Y. 2010. Consequences of poplar overspread on agricultural land and its treatment. Reform , (2): 76-81. (in Chinese)
34 Tan F Y, Wang J L, Song Y B, et al. 2009. Analysis of changing characteristics of agricultural climate resources over last 45 years in North China plain. Chinese Journal of Agrometeorology , 30(1): 19-24.
35 Watelet A. 2009. Agricultural land-cover changes in eastern Ontario from 1826 to 2006: environmental effects. Canadian Geographer , 53(1): 45- 62.
36 Xie Y. 2001. A preliminary study on the economic benefits of agroforestry in poplar plantation. East China Forest Management , 15(3): 19-21. (in Chinese)
37 Xie Y, Yu M, Tian G, et al. 2005. Socio-economic driving forces of arable land conversion: A case study of Wuxian city, China. Global Environmental Change , 15(3): 238-252.
38 Xu C, Sui P, Xie G H, et al. 2006. Soil water effect and productivity in poplar and wheat-corn agroforestry system. Scientia Agricultura Sinica , 39(4): 758-63. (in Chinese)
39 Yang W X. 1996. The preliminary discussion on soil desiccation of artificial vegetation in the northern regions of China. Scientia Silvae Sinicae , 32(1): 78-84. (in Chinese)
40 Yang C D. 1997. Researches on the productivity decline of artificial forests site, Forest and Soil . Beijing: China Science and Technology Press. (in Chinese)
41 Yin C M, Sui P, Chen Y Q, et al . 2008. Soil water consumption and effects of poplar in farmland of the low Hai River plain. Chinese Agricultural Science Bulletin , 24(3): 435-440. (in Chinese)
42 Yu X T. 1992. A summary of the studies on the plantation productivity and nutrient cycling in Chinese fir plantation ecosystem. Journal of Fujian College of Forestry , 12(3): 264-275. (in Chinese)
43 Zhang F S. 1993. The reason and effect of rhizosphere pH value change caused by the root of the plant. Chinese Journal of Soil Science , 24(1): 43-45. (in Chinese)
44 Zhang W J, Li C S, Feng J X, et al . 2001. Agricultural structure adjustment and dynamic changes of food consumption between urban and rural residents in the Yangtze River Delta. Journal of Nanjing Agricultural University , 24(1): 108-12. (in Chinese)
45 Zhao Y L, Li X B, Xin L J, et al. 2012. Driving forces of “poplar expansion and cropland shrinkage” in the North China plain: A case study of Wen’an county, Hebei province. Geographical Research , 31(2): 323- 333. (in Chinese)
46 Zhong S Y, Li K. 2009. Countermeasure for farmland protection based on food security. China Soft Science , (9): 1-8. (in Chinese)