中国林学(英文版)
中國林學(英文版)
중국림학(영문판)
FORESTRY STUDIES IN CHINA
2010年
2期
49-54
,共6页
yield map%estimation model%classification map%acorn%spatial synchrony%hyperspectral imagery%masting
Masting is a well-marked variation in yields of oak forests. In Japan, this phenomenon is also related to wildlife man-agement and oak regeneration practices. This study demonstrates the capability of integrating remote sensing techniques into map-ping spatial variation of acorn production. The hyperspectral images in 72 wavelengths (407-898 rim) were acquired over the study area ten times over a period of three years (2003-2005) during the early growing season of Quercus serrata using the Airborne Im-aging Spectrometer Application (AISA) Eagle System. With the canopy spectral reflectance values of 22 sample trees extracted from the images, yield estimation models were developed via multiple linear regression (MLR) analyses. Using the object-oriented classi-fication approach in eCognition, canopies representative of individual oak trees (Q. serrata) were identified from the corresponding hyperspectral imagery and combined with the fitted estimation models developed, acorn yield over the entire forest were estimated and visualized into maps. Three estimation models, obtained for June 27 in 2003, July 13 in 2004 and June 21 in 2005, showed good performance in acom yield estimation both for the training and validation datasets, all with R2 > 0.4, p < 0.05 and RRMSE < 1 (the relative root mean square of error). The present study shows the potential of airborne hyperspoctral imagery not only in estimating acorn yields during early growing seasons, but also in identifying Q. serrata from other image objects, based on which of the spatialdistribution patterns of acorn production over large areas could be mapped. The yield map can provide within-stand abundance and valuable information for the size and spatial synchrony of acorn production.