Eucalyptus Leaf Area Index Estimated by Vegetation Indices Using Landsat-5 TM Images

ABSTRACTThe objective of the present study was to fit regression models to the measured leaf area in eucalyptus forests and vegetation indices derived from Landsat-5 TM images. The study was carried out in commercial plantations located in the basin of the Doce River, Minas Gerais state, between 2008 and 2011. Leaf area was measured in the field, non-destructively, with the LAI-2000 device. The following indices were used: Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), and Simple Ratio (SR). The best model was adjusted from the NDVI, with a correlation coefficient of 0.73 and root mean square error of 0.37 m² m–2 (19%). We conclude that the leaf area index can be estimated by the regression models fit to the vegetation indices derived from the Landsat - 5 TM images.

摘要 本研究旨在针对桉树人工林的实测叶面积，以及由Landsat-5 TM影像提取的植被指数拟合回归模型。本研究于2008年至2011年间，在巴西米纳斯吉拉斯州多西河（Doce River）流域的商品人工林内开展。叶面积采用LAI-2000设备在野外进行无损测定。本次研究所用植被指数包括：归一化差值植被指数（Normalized Difference Vegetation Index，NDVI）、土壤调节植被指数（Soil Adjusted Vegetation Index，SAVI）以及简单比值指数（Simple Ratio，SR）。最优拟合模型由NDVI构建，其相关系数为0.73，均方根误差为0.37 m²·m⁻²（19%）。综上，可通过拟合自Landsat-5 TM影像提取的植被指数的回归模型，对叶面积指数进行估算。