论文部分内容阅读
There has been a great deal of interest in studying the crown of trees using remote sensing data.In this study,crownwidth was extracted from high-resolution QuickBird images for open Populus xiaohei plantations.Regression modelsfor predicting the individual stem volumes of Populus xiaohei were established using extracted crown width,as well asestimated tree parameters(i.e.diameter at breast height[DBH]and tree height)as predictors.Our results indicated thatcrown width could be accurately extracted from QuickBird images using a multi-scale segmentation approach with a meanrelative error of 5.74%,especially for wide-spacing stands.Using either extracted crown width alone or with estimatedDBH and tree height can successfully estimate individual stem volume of Populus xiaohei with the R~2 value ranging from0.87 to 0.92 depending on different model forms.In particular,the two second-order polynomial models(model2 andmodel 6),based on QuickBird image-derived crown widths and estimated DBH and tree heights,respectively,were the bestat describing the relationship between stem volume and tree characteristics.
There has been a great deal of interest in studying the crown of trees using remote sensing data. In this study, crownwidth was extracted from high-resolution QuickBird images for open Populus xiaohei plantations.Regression models for predicting the individual stem volumes of Populus xiaohei were established using extracted crown width, as well as sestimated tree parameters (iediameter at breast height [DBH] and tree height) as predictors.Our results indicated thatcrown width could be normally extracted from QuickBird images using a multi-scale segmentation approach with a mean relative error of 5.74%, especially for wide-spacing stands.Using either extracted crown width alone or with estimatedDBH and tree height can successfully estimate individual stem volume of Populus xiaohei with the R ~ 2 value ranging from 0.87 to 0.92 depending on different model forms. particular, the two second-order polynomial models (model2 and model 6), based on QuickBird image-derived crown widths and estimated DBH an d tree heights, respectively, were the bestat describing the relationship between stem volume and tree characteristics.