ACTA ECOLOGICA SINICA Vol. 26,No. 12 Dec., ,, 3, 4 5,,6 1,, 3, 3, Ellis Erle C. 5 (11, ; 21, ; 31, ; 41, 510

Transcription

1 ACTA ECOLOGICA SINICA Vol. 26,No. 12 Dec., ,, 3, 4 5,,6 1,, 3, 3, Ellis Erle C. 5 (11, ; 21, ; 31, ; 41, ; 51Department of Geography and Environmental Systems, University of Maryland, Baltimore County, Maryland, USA, ; 61Environmental Sciences Institute, Florida A&M University, Tallahassee, Florida, USA) :,, 1m IKONOS, ;, ; Π : hm 2,0 30cm 76197Tg Π,, 1, 5 83 % 85 % hm 2, 42 % ; 0 30cm 36160Tg, 48 %, Π, m : ; ; ; ; : (2006) :Q143 :A Landscape structure, management and soil organic carbon in the densely populated village landscapes of China s Yangtze Delta Plain WU Jun2Xi 1, J IAO Jia2Guo 2, 3, XIAO Hong2Sheng 4, WANG Hong2Qing 5,6, CHENG Xu 1, 3, YANG Lin2Zhang 3, ELLIS Erle C1 5 (11Department of Agronomy & Agroecology, China Agricultural University, Beijing , China ; 21 Department of Resources & Environmental Sciences, Nanjing Agriculture University, Nanjing, Jiangsu , China ; 31 Institute of Soil Science, Chinese Academy of Sciences, Nanjing, Jiangsu , China ; 41 Institute of Tropical & Subtropical Ecology, South China Agricultural University, Guangzhou, Guangdong , China ; 51Department of Geography and Environmental Systems, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA ; 61 Environmental Sciences Institute, Florida A &M University, Tallahassee, Florida, USA). Acta Ecologica Sinica,2006,26( 12) : Abstract :We examined interactions between landscape structure, land management and soil organic carbon ( SOC; top 30 cm) : ( Grant DEB ) : ; : : (1975 ),,,,. E2mail : com 3 Corresponding author. edu. cn : ( Grant :DEB ) ; Ellis Erle C1,,, ;,, Foundation item :The US National Science Foundation under Grant DEB awarded to Ellis Erle C. in 2000 Received date : ; Accepted date : Biography :WU Jun2Xi, Ph. D. candidate, mainly engaged in village landscape ecology. E2mail : com

2 within the densely populated village landscapes of the Yangtze Delta Plain based on an intensive field study in Yixing Municipal, a regionally2representative sample of the Yangtze Delta Plain. We mapped landscapes at a high spatial resolution and classified them into ecologically2distinct features ( ecotopes) by the direct interpretation and field validation of features in 2002 IKONOS imagery using a standardized mapping procedure. We then collected samples of soils and sediments for analysis at random points within ecotope features selected by a regionally2weighted stratified sampling design. The five most extensive land use Πland cover categories in the Yangtze Delta Plain were paddy, built structures with impervious cover, aquaculture, rainfed annual and irrigated perennial croplands, which occupied 83 % of the total area and contained 85 % of the total SOC stored in the region s village landscapes. Regional scaling analysis indicates that hm 2 of Yangtze Delta Plain village landscapes (estimated from Landsat imagery) sequestered Tg of SOC, of which 48 % was in paddy land (37 Tg), covering 42 % of the region s total surface area ( hm 2 ). By combining a regionally2stratified sample of fine2scale landscape features with a regionally2 weighted upscaling analysis, the role of land use Πland cover in determining local SOC patterns and the regional consequences of these patterns were revealed across a densely populated agricultural region of China. This fine2scale approach to investigating land management practices and their impacts on soil carbon and other ecosystem properties offers significant advantages over conventional lower2resolution methods for land cover and SOC assessments based on the regional soil types. Key words : Yangtze Delta Plain ; village landscape ; ecotope ; soil organic carbon density ; soil organic carbon storage, Π [1, 2 ], [3 ], Πkm 2, 25 % 25 [4 ],,, 67 %, 26 % km 2 [3, 4 ] [4, 5, ] [ m ] ( < 30m ) Π, [3,4, ], [13 25 ], ;, [26 29 ] [30 32, ], 1m IKONOS, Π ;, ( < 30m), 1 Verburg K [4,5 ], Landsat 7 ETM + 7 ( , 2815m, UTM51N) Π 0 30cm, ( 1) [4,5 ],,

3 12 : 4137 Π, Landsat, IKONOS [ m 500m ] 1 ERDAS Landsat 5 [4 ] ( 1), 84 % Kappa 0181 (500 m 500 m) (Arcgis813), < 50m ; 9715 %, 75 % 25 %, 5, (Two Step cluster ) K ( K2mean cluster) [4 ] 2, ; 2, 1 (82127 ) :, 2 (2972 ) : ,3,4,5,6,7,10 15 K ; 3, 100km 2 [33 ] IKONOS, 1 (32780, ) 5 ; 2 (32709, ) 4 ; 3 (19610,, ) 3 12 [4 ] ; 9, 3 Landsat,, ( 1) Land cover 1,,, Table 1 Comparison of land useπland cover among sampled cells, site, Yixing Municipal and Yangtze Delta Plain 3 Region Yixing Municipal Site Sample Correct sample Village builtup ( %) Urban builtup ( %) Paddy( %) Other agriculture crop ( %) Water ( %) Area of village landscape (hm 2 ) Percent land cover was estimated from the 2815m classified land cover dataset and from the sample cells corrected using the regional weighted [4 Ellis ( : CDW) ] : CDW i = n k 1 1 CD iπ 2 i CD 2 i N k N t (1) (1) CDW i i ; CD i i k ; n k k ; N k k ; N t I I CDW ECOj = ECO ij CDW i Π i i A i (2) (2) CDW ECOj ( Ecotope) j ; I ; ECO ij i ( Ecotope) j ; CDW i i,a i i R ECOj = CDW ECOj A r (3) (3) R ECOj ( Ecotope) j, A r

4

5 12 : , (Anthropogenic Ecotope Mapping & Classification (AEM) [34 ] 4 : (Land form) (Land use) (Land cover) ( Group) + ( Type) 2, Π ( Type), 4, (ecotope) [3,4,34 37 ] : FPPAri01, : FP ( Floodplain), : P ( Paddy), : A (Annual ), Π : ri (Hydromorphic crops) (01) Π,, 1m IKONOS, GPS, Arcgis [4,34,36,37 ] : 2m ; 5m 25m 2 ; 10m 100m 2, ( Ecotope) [4,34,36 ] Code Land form Description 2 4 Table 2 Ecotope classification levels and classes for village landscapes Code Land use Description Land cover Code Description Code Π Group Description AN Anthropogenic A Aquaculture A Annual ac Annual crops FP Floodplain C Constructed E Bare soil aq Aquaculture CA < 30m Small canal D Disturbed M Mixed db Disturbed & Debris CB > 30m Large canal F Fallow P Perennial dw Deciduous woody crops PA < 30m Small pond I Irrigated S Sealed dt Deciduous broadleaf trees PB > 30m Large pond L Livestock W Water ho Housing FM < 1m Flowing Marsh M Mine & Fill hv Hydromorphic vegetation MA < 1m Marsh O Ornamental ir Irrigation < 1m > 10m CM P Rice paddy or other flooded Margins of canal crops nb Non2industrial < 1m > 10m WM R Rainfed os Other sealed Margins of Lentic waterbody T Forestry pp Public plantings ri tg tr wa Hydromorphic crops Tall graminoids Transportation Water surface [4 ] s, ( 1 2),, Ellis : 3km 2 (12 Cells) 150 (, ), 3 : http :ΠΠwww. ecotope. orgπaemπ

6 ( Ecotope), Π (FUC = Form + Use + Cover) (UC = Use + Cover) ( 1 2), N = 150 CDW ( Ecotope or FUC or UC) ; Π Π, 3, s, 10 5, Π 015 %, 3,, 150,,,, 12, 1 1,, GPS, GPS, 5108cm, 30cm,, 0 15cm 15 30cm,, 10m, 30cm, 3. 3,, 2mm, 80g, 0125mm, : = 2mm Π ; = 2mm Π -, SOC dj n = 10 C ij AWD ij i = (4), SOC dj j 0 30cm (tπhm 2 ) ; n n ; C ij j i (gπkg) ; AWD ij j i > 2mm (gπcm 3 ) ;0115 i (m) ( : 013m) SOC rj = SOC dj R ECOj (5), SOC rj j 0 30cm ; SOC dj j 0 30cm ; R ECOj j N SOC i = SOC dj j R ECOj (6), SOC t 0 30cm, N ( Ecotope) 110, (Form) 10, (Use) 11, (Cover) 6, Π (UC) 25, Π (FUC) 49, Π ( Group) 25, ( Group + Type) 73

7 12 : , 51 ( 3 4) ( Ecotope) 26, 2316 % ; Π (UC) 15, 6010 % ; Π (FUC) 21, 4219 %,, %, %, 0 15cm 15 30cm tπhm tπhm 2 ( 3) 0 15cm, 15 30cm, (ANCSnb06) (ANOMpp05), 0 15cm 15 30cm,,, (ANCStr02) (ANOMpp05), ; 2,, (Form = AN) Ecotope code and description cm Table 3 SOC density of ecotope classes in 0 15cm layers and 15 30cm layers, respectively Sample number (0 15cm) S Mean (tπhm 2 ) (15 30cm) S Mean (tπhm 2 ) FPIPdw39 Irrigated small2scale mature mulberry a a FPRPdw39 Rainfed small2scale mature mulberry a a FPPAri01 Rice paddy ab a FPIAac01 Irrigated small2scale intensive crops ab a ANDAdb06 Disturbed herbaceous vegetation with debris ab a FPRAac04 1 Rainfed small2scale staple crops abc a FPRAac01 Rainfed small2scale intensive crops abc a FPDMdb07 Disturbed woody with debris abc a FPIAac04 1 Irrigated small2scale staple crops abc a ANCSho04 Attached > 1 story house abc a FPDPdb08 Disturbed trees with debris abc a ANRAac04 1 Rainfed small2scale staple crops abc a ANCEir01 Irrigation & drainage ditch with bare soil abc a ANTAtg01 Planted tall graminoid abc a ANCStr02 Paved road abc a ANCSnb06 Large public buildings bc 9100 a ANOMpp05 Public planting woody with linear c a Total S : SNK ( p < 0105) Means of ecotope classes with different letters are statistically significantly different ( p < 0105) as tested using Student2Newman2Keuls(SNK) from GLM( p < 01001) ; : 0 15cm 15 30cm T ( p < 0105) ( p < 0101) Mean of ecotope classes with asterisk and double asterisks are statistically significantly different ( p < 0105 or p < 0101) as tested using independent2sample T test between 0 15cm and 15 30cm layers, respectively 0 30cm 26128tΠhm 2 ( 4), (MAFAhv01),,

8 ; ;,,, Π [29,30 ], 4. 2 Π 12 Π ( 5 1 6), Π (FUC),, Π (UC),, Ecotope code and description cm Table 4 The sediment SOC density in 0 30 cm layer for ecotope classes Sample (0 30cm) number Mean S (tπhm 2 ) MAFAhv01 Fallow persistent emergent grass2like vegetation in marsh a 6 % CMDAhv01 ( ) Disturbed persistent emergent grass2like vegetation on canal margin b 8 % PAAWaq07 < 011hm 2 Small2scale generic freshwater livestock culture in small pond bc 10 % PBAWaq hm 2 Medium2scale generic freshwater crab culture in large pond bc 8 % PBAWaq hm 2 Medium2scale generic freshwater livestock culture in large pond bc 6 % FMFAhv01 ( ) Fallow persistent emergent grass2like vegetation in flowing marsh bc 7 % CAAWaq08 < 30m 011 1hm 2 Medium2scale generic freshwater livestock culture in small canal bc 8 % CBFWwa02 > 30m Fallow water in large canal bc 7 % CAFWwa02 < 30m Fallow water in small canal c 7 % Total % CV( %) S : SNK ( p < 0105) Means of ecotope classes with different letters are statistically significantly different ( p < 0105) as tested using Student2Newman2Keuls (SNK) from GLM( p < 01001) ; : Π ; SE ΠMean Landsat hm 2,0 30cm 76197Tg( 6),, 42 % 48 %( 2 6) ;, 15 % 11 % ;, 5 Table 5 CDW ( %) of sample cells for estimating village landscape of Yangtze Delta Plain and Yixing Municipal, respectively CDW ( %) CDW ( %) Sample cell For Yangtze Delta Plain For Yixing Municipal R10 - C R09 - C R05 - C R07 - C R09 - C % 10 % ; 5 Π, 83 % 85 % 5 %( 2) (PA, RA, IP, IA, RP, IM, RM) hm 2 ( 2 6), 63 % ; (PA) ( IP, IA, IM) ( RA, R05 - C R08 - C R09 - C R06 - C R06 - C R09 - C R08 - C RP, RM) 67 % 17 % 16 % 53195Tg, 70 % ;, 68 %,17 % 14 % ( 6) : ( FPPAri01), ( FPIPdw39),

9 12 : 4143 (FPRAac04,ANRAac04) (FPRAac01), (AW), hm 2 (aq08 aq14) 1 hm 2 (aq09) ; 011 hm 2 (aq07), 1 % 015 %, (CB CA) ( PB PA), 714 % 711 %( 6) (CS), : (ANCSho04), ( ANCStr02) (ANCSnb06) Π Fig. 2 The area percent and the SOC percent of land useπland cover in the Π Yangtze Delta Plain, respectively, PA : Paddy&other flooded crops ; AW: Aquaculture ; CS: Π, ( 7), Built structures with impervious cover ; RA : 1 Rainfed annual croplands ; IP : Irrigated perennial croplands ; FW: Fallow water ; IA : 1 Irrigated annual croplands ; DA : 1 Disturbed area covered annual herbaceous vegetation ; FA : 1 (500m 500m cells), Fallow area covered annual herbaceous vegetation ; DM: :,,, Disturbed area covered mixed of herbaceous, open woody & tree cover ; RP : Rainfed perennial croplands ; CE: Built structures with bare soil ; TA : Managed for regular harvest of non-crop herbaceous vegetation ; :, > 1. 0 % Π Note : Land useπland cover 12 classes that area are > 1. 0 % only are charted ( CDW), ( 5 7) hm 2, 011 % ( 7) hm 2, 114 % ; hm 2, 119 %,, 3313 %, < 410 % ; Π hm 2, 216 % :, :,, :,,,. 2004

10 Table 6 Ecotope area and SOC storage in village landscape of the studied region on Yangtze Delta Plain Π Land useπland cover and ecotope code ( %) Area of total Area (10 3 hm 2 ) ( %) SOC of total SOC(Tg) Paddy &other flooded crops FPPAri Aquaculture PBAWaq CBAWaq CAAWaq PBAWaq PAAWaq PBAWaq Built structures with impervious cover ANCSho ANCStr ANCSnb Rainfed annual croplands FPRAac ANRAac FPRAac Irrigated perennial croplands FPIPdw Total : > 510 % Π > 015 % ; Land use Πland cover classes that area are > 510 % only are listed, in which ecotope classes are comprised and are list only that area are > 015 % ; : 3 4 ; Ecotope description is saw in table 3 and table 4 ; : 0 30cm ; The total area and 0 30cm SOC storage of village landscape of the studied region on Yangtze Delta Plain 7 Π Table 7 Comparison of estimating land use and land cover areas with surveying land use area in the village landscape of Yixing Municipal Compared code S Π Area deviation Estimating Area (10 3 hm 2 ) Surveying Area (10 3 hm 2 ) (10 3 hm 2 ) S S Relative deviation( %) Paddy Aquatic and transitional Built2up structures Rainfed croplands Perennial woody crops Perennial woody vegetation Annual herbaceous vegetation Irrigated croplands Other types Total : CDW Π ( a) ; The area of the land use Πland cover classes was estimated using the regional weighted( CDW) ; : ( b), ; The surveying area of the land use classes came from Arable Land Quality Survey and Appraisement of Yixing Municipal in Jiangsu Province ; S : (Area deviation) = a - b ; S S : (Relative deviation) = ( a - b)π{ ( a + b)π2},, ( 8), 0 15cm (68 ),, ; (61 ) [30 ],, 0 15cm,,. 2004

11 12 : 4145 ( gΠkg) 0 15cm 1994 (14162 gπkg) 1983 (12131 gπkg),, 1994 [ ], 0 15cm [23 ] (0 25cm), 0 30cm (9117 gπkg) (14104 gπkg), (12174 gπkg), [38 ] :80, ( ) gπkg( 22120gΠkg), gπkg( 28137gΠkg), 2718 % 100, 85 % ( ), 15 % Region of sample soil Yixing Municipal Yixing Municipal Yixing Municipal Yixing Municipal 8 Table 8 Comparing SOC, bulk density, thickness and SOC density with other study references SOC (gπkg) Bulk density (gπcm 3 ) Thickness (cm) SOC density (tπhm 2 ) Note S (2005) (2005) (2005) (2003) Yixing Municipal (2002) [30 ] Yixing Municipal (1994) [30 ] Yixing Municipal (1983) [30 ] Jiangsu Province (SNSSC) 3 [23 ] Taihu Region (SNSSC) 3 [23 ] Lixiahe Region (SNSSC) 3 [23 ] Ningzhen Hill Region (SNSSC) 3 [23 ] Region along Yangtze River (SNSSC) 3 [23 ] Region along the coast (SNSSC) 3 [23 ] Xuhui Region (SNSSC) 3 [23 ] ( ) East China (plow layer) (SNSSC) [14 ] ( ) East China (plowpan) (SNSSC) [14 ] ( ) China (plow layer) (SNSSC) [14 ] ( ) China (plowpan) (SNSSC) [14 ] ( ) China (whole topsoil) (SNSSC) [14 ] S : Standard deviations ; :, 1130gΠcm 3, Bulk density that was not shown in the reference was filled in with 1130gΠcm 3, : The study time of sample soil 3 SNSSC,The second national soil survey of China 0 15cm ( 8),, 15 30cm ;, 0 15cm 0 [14 30cm ] [38 ],,,,,, [13 25 ],,,,, hm 2

12 %, 0 15cm 2120Tg [30 ] hm 2,0 15cm 1125Tg, ( hm 2,2002 ) hm 2, 0 15cm 2135Tg,,,,,,, Π, : < 30m [3,4,34 37 ],, ( ),, ;,,,, : Π,, References : [ 1 ] Houghton R A, Martin R E1 Effect of land2use change on the carbon balance of terrestrial ecosystems. In : DeFries R S, Asner G P, Houghton R A eds. Ecosystems and land use change. Geophysical Monographs. American Geophysical Union, Washington, D C : [ 2 ] Houghton R A. Revised estimates of the annual net flux of carbon to the atmosphere from changes in land use and land management Tellus, 2003, 55B : [ 3 ] Ellis E C, Li R G, Yang L Z, et al. Long2term change in village scale ecosystems in China using landscape and statistical methods. Ecological. Applications, 2000, 10 (4) : [ 4 ] Ellis E C. Long2term ecological changes in the densely populated rural landscapes of China. In : DeFries R S, Asner G P, Houghton R A eds. Ecosystems and land use change. Geophysical Monographs. American Geophysical Union, Washington, D C. 2004, 153 : [ 5 ] Verburg P H, Veldkamp A, Fresco L O. Simulation of changes in the spatial pattern of land use in China. Applied Geography, 1999, 19 (3) : [ 6 ] Wang S Q, Xu J, Zhou C H. Using remote sensing to estimate the change of carbon storage : a case study in the estuary of Yellow River delta. International Journal of Remote Sensing, 2002, 23 (8) : [ 7 ] Liu J Y, Liu M L, Tian H Q, et al. Spatial and temporal patterns of China s cropland during : An analysis based on Landsat TM data. Remote Sensing of Environment, 2005, 98 : [ 8 ] Zhan X, Defries R, Townshend J R G, et al. The 250m global land cover change product from the Moderaten Resolution Imaging Spectroradiometer of NASA s Earth Observing System. International Journal of Remote Sensing, 2000, 21 (6&7) : [ 9 ] Liu J Y, Zhuang D F, Luo D, et al. Land2cover classification of China : integrated analysis of AVHRR imagery and geophysical data. International Journal of Remote Sensing, 2003, 24(12) : [10 ] Loveland T R, Reed B C, Brown J F, et al. Development of a global land cover characteristics database and IGBP DISCover from 1 km AVHRR data. International Journal of Remote Sensing, 2000, 21(6&7) : [11 ] Frolking S, Xiao X M, Zhuang Y H, et al. Agricultural land2use in China : a comparison of area estimates from ground2based census and satellite2borne remote sensing. Global Ecology and Biogeography, 1999, 8 : [12 ] Lepers E, Lambin F E, Janetos C A, et al. A synthesis of information on rapid land2cover change for the period Bioscience, 2005, 55(2) : [13 ] Wang S Q, Tian H Q, Liu J Y, et al. Pattern and change of soil organic carbon storage in China : 1960s 1980s. Tellus, 2003, 55B : [ 14 ] Pan G X, Li L Q, Wu L S, et al. Storage and sequestration potential of topsoil organic carbon in China s paddy soils. Global Change Biology, 2003, 10 : [15 ] Wu H B, Guo Z T, Peng C H. Land use induced changes of organic carbon storage in soil of China. Global Change Biology, 2003, 9 : [ 16 ] Zhong L, Zhao Q G. Organic carbon content and distribution in soils under different land uses in tropical and subtropical China. Plant and Soil, 2001, 231 : [17 ] Pan G X. Study on carbon reservoir in soils of China. Bulletin of Science and Technology, 1999, 15(5) :

13 12 : 4147 [18 ] Wang S Q, Zhou C H. Estimating soil carbon reservoir of terrestrial ecosystem in China. Geographical Research, 1999, 18 (4) : [19 ] Wang S Q, Zhou C H, Li K R, et al. Analysis on spatial distribution characteristics of soil organic carbon reservoir in China. Acta Geographica Sinica, 2000, 55 (5) : [20 ] Wang S Q, Liu J Y, Yu G R. Error analysis of estimating terrestrial soil organic carbon storage in China. Chinese Journal of Applied Ecology, 2003, 14 (5) : [21 ] Xie X L, Sun B, Zhou H Z, et al. Organic carbon density and storage in soil of China and spatial analysis. Acta Pedologica Sinica, 2004, 41 (1) : [22 ] Yu D S, Shi X Z, Sun W X, et al. Estimation of China soil organic carbon storage and density based on soil database. Chinese Journal of Applied Ecology, 2005, 16(12) : [ 23 ] Li L Q, Pan G X. Estimation of cropland soil organic carbon density and storage in Jiangsu Province. Chinese Agricultural Science Bulletin, 1999, 15(6) : [24 ] Liu G H, Fu B J, Wu G, et al. Soil organic carbon pool and its spatial distribution pattern in the Circum Bohai Region. Chinese Journal of Applied Ecology, 2003, 14(9) : [25 ] Jiang X S, Pan J J, Li X L. Organic carbon density and storage in topsoil of Jiangsu and spatial analysis. Chinese Journal of Soil Science, 2005, 36(4) : [26 ] Shen Y, Huang Y, Zong L G, et al. Simulation and prediction of soil organic carbon dynamics in Jiangsu Province based on model and GIS techniques. Scientia Agricultura Sinica, 2003, 36 (11) : [ 27 ] Chen F, Pu L J, Cao H, et al. Spatial and temporal changes of soil nutrients and their mechanism in typical area of Taihu Lake valley during the past two decades. Acta Pedologica Sinica, 2002, 39(2) [ 28 ] Gao C, Zhang TL, Wu W D. Agricultural soil nutrient status in Taihu Lake Area and its implication to nutrient management strategies. Scientia Geographic Sinica, 2001, 21 (5) : [29 ] Li L Q, Pan G X, Gong W, et al. Organic carbon storage in selected paddy soil in Taihu Lake Region and their occurrence. Bulletin of Science and Technology, 2000, 16(6) : [30 ] Zhang Q, Li L Q, Pan G X, et al. Dynamics of topsoil organic carbon of paddy soils at Yixing over the last 20 years and the driving factors. Quaternary Sciences, 2004, 24(2) : [31 ] Fu B J, Guo X D, Chen L D, et al. Land use changes and soil nutrient changes : a case study in Zunhua County, Hebei Province. Acta Ecologica Sinica, 2001, 21 (6) : [32 ] Kong X B, Zhang F R, Qi W, et al. The influence of land use change on soil fertility in intensive agricultural region : a case study of Quzhou County, Hebei. Acta Geographica Sinica, 2003, 58 (3) : [33 ] Wang H Q, Ellis E C. Spatial accuracy of orthorectified IKONOS imagery and historical aerial photographs across five sites in China. International Journal of Remote Sensing, 2005, 26 : [ 34 ] Ellis E C, Wang H Q, Xiao H S, et al. Measuring long2term ecological changes in densely populated landscapes using current and historical high resolution imagery. Remote Sensing of Environment, 2006, 100 : [35 ] Ellis E C, Li R G, Yang L Z, et al. Changes in village2scale nitrogen storage in China s Tai Lake Region. Ecological Applications, 2000, 10 : [36 ] Li S C, Liu W Q, Cheng X, et al. Characteristic study on village landscape patterns in Sichuan Basin hilly region based on high resolution IKONOS remote sensing. Chinese Journal of Applied Ecology. 2005, 16(10) : [37 ] Ruan R Z, Ellis E C. An illustrative study on local landscape based on IKONOS. Remote Sensing Information, 2005, 3 : [38 ] Yu H, Huang J K, Scott R, et al. Soil fertility changes of cultivated land in Eastern China. Geographical Research, 2003, 22(3) : : [17 ].., 1999, 15 (5) : [18 ],.., 1999, 18 (4) : [19 ],,,.., 2000, 55 (5) : [20 ],,.., 2003, 14 (5) : [21 ],,,.., 2004, 41 (1) : [22 ],,, , 2005, 16 (12) : [23 ],.., 1999,15(6) : [24 ],,,.., 2003, 14 (9) : [25 ],,.., 2005, 36 (4) : [26 ],,,. GIS., 2003, 36 (11) : [27 ],,,. 20., 2002, 39 (2) : [28 ],,.., 2001, 21 (5) : [29 ],,,.., 2000, 16 (6) : [30 ],,,. 20., 2004, 24 (2) : [31 ],,,.., 2001, 21 (6) : [32 ],,,.., 2003, 58 (3) : [36 ],,,.., 2005, 16 (10) : [37 ], Ellis E C. IKONOS., 2005, 3 : [38 ],, Scott Rozelle,.., 2003, 22 (3) :