Advances in studies on the structure of farmland shelterbelt ecosystem Projective and contractive aberrations of shelterbelt porosity estimated by measuring photograph with the help of digitized photographic silhouettes Study on random error of shelterbelt porosity estimated by measuring photo with the help of digitized photographic silhouettes Determination of dominant factors of site with linear model theory: division of farmland shelterbelt sites in Hilly Areas of Chaoyang Estimates of the Wind Protection Effect and the Relative Dynamic Speed above the Canopy of A Large Oasis Area Extracting Farmland Shelterbelt Automatically Based on ZY-3 Remote Sensing Images Evaluation of Wind Protection Effect of Oasis Shelterbelts in China STUDY ON THE MATTER CIRCULATION AND ENERGY FLOW OF AN ARTIFICIAL ECOSYSTEM OF THE FARMLAND SHELTERBELT Effect of arable land fragmentation on farmland-forest network at village level in typical agricultural regions of North China Plain-A case of Quzhou County, Hebei Province Effects of Coordinate Rotation on Precision of Heat and Latent Fluxes Estimating in Farmland Shelterbelts Algorithm Derivation of Winter Facies Wind Protection of Shelterbelts Structural Parameters and Wind Permeability Coefficient