《Wetland Ecology and Management》杂志刊登“季节变化对高光谱数据估算红树林叶绿素a含量的影响”

作者：Francisco Flores-de-Santiago, John M.Kovacs, Francisco Flores-Verdugo

刊物：《Wetland Ecology and Management》,2013年4月

关键词：红树林；高光谱；叶绿素a；墨西哥

摘要：红树林的光合活性以及生理应激能通过叶绿素a测量值间接检测到。最近的研究表明，通过高光谱植被指数来估算红树林叶绿素a含量是可行性的，但是至今仍没有对不同季节（旱季或雨季）收集到的高光谱数据开展研究。本研究中，收集了墨西哥太平洋亚热带森林红树林的树叶，用于叶绿素a含量的测定和高光谱测量(450-1000nm)。我们于旱季和雨季从同一批树上共收集了360个样本，特别测试了35个指数来计算叶绿素a含量。调查了的种红树林（美洲红树、黑皮红树、假红树）表现出不同的健康状况。主成分分析和线性回归分析用来确定哪个植被指数能更好的预测红树林叶绿素含量a。结果表明通过高光谱测量计算得到的植被指数在估计树叶叶绿素含量方面，旱季要优于雨季。在35个植被指数中，R₇₄₀/R₇₂₀指标是预测红树林叶绿素含量的最佳指标，R2值在旱季和雨季分别为0.8和0.68。这些结果表明在旱季进行高光谱测量可用于识别亚热带区域中红树林的应力（即健康状态）变化。

The influence of seasonality in estimating mangrove leaf chlorophyll-a content from hyperspectral data

Authors: Francisco Flores-de-Santiago,John M.Kovacs,Francisco Flores-Verdugo

Journal: Wetland Ecology and Management,April 2013 Abstract: Mangrove photosynthetic activity and, consequently, physiological stress can be monitored indirectly using leaf chlorophyll-a (Chla) measurements. Recent studies have demonstrated the feasibility of mangrove leaf Chla content estimation from in situ hyperspectral vegetation indices (VI) but no such research has been conducted using data collected from contrasting seasons (i.e. dry and rainy). In this study, mangrove leaves were collected in a sub-tropical forest of the Mexican Pacific for Chla content determination and in situ hyperspectral measurements (450–1,000 nm). Specifically, we tested 35 VI to estimate Chla content based on a leaf sample of 360 collected from the same trees during both the dry and rainy seasons. The forest examined contained three species of mangrove (Rhizophora mangle, Avicennia germinans and Laguncularia racemosa) exhibiting various conditions of health (dwarf condition, tall and healthy). A principal component analysis, followed by linear regression analyses, were conducted in order to identify those VI that best predict mangrove leaf Chla content during the two seasons. The results indicate that VI derived from hyperspectral measurements collected during the dry season are better at estimating leaf Chlacontent than those collected during the rainy season. Among the 35 VI, the Vog1 (R740/R720) index was found to be the best predictor of mangrove leaf Chla content, resulting in R 2 values of 0.80 and 0.68 for the dry and rainy season respectively. These results would suggest that for identifying variation in mangrove forest stress (i.e. health) in sub-tropical regions, hyperspectral measurements should be carried out during the dry season.

原文链接：http://link.springer.com/article/10.1007/s11273-013-9290-x

翻译：刘金轲；审阅：翟正丽