The State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China.
Environ Sci Process Impacts. 2015 Apr;17(4):753-62. doi: 10.1039/c5em00061k.
Wetland ecosystems are very important for ecological diversity and have a strong ability to sequester carbon. Through comparisons with field measured eddy covariance data, we evaluated the relationships between the light use efficiency (LUE) index and the enhanced vegetation index (EVI), normalized difference vegetation index (NDVI), and land surface temperature (LST). Consequently, we have proposed a new model for the estimation of gross primary production (GPP) for wetland ecosystems using Moderate Resolution Imaging Spectroradiometer (MODIS) products, including these vegetation indices, LST and the fraction of photosynthetically active radiation (FAPAR) absorbed by the active vegetation. This model was developed and validated for a study site on Chongming Island, Shanghai, China. Our results show that photosynthetically active radiation (PAR) was highly correlated with the LST, with a coefficient of determination (R(2)) of 0.59 (p < 0.001). Vegetation indices, such as EVI, NDVI and LST, were highly correlated with LUE. We found that the product of vegetation indices (VIs) and a modified form of LST (Te) can be used to estimate LUE, with an R(2) of 0.82 (P < 0.0001) and an RMSE of 0.054 kg C per mol PAR. This new model can provide reliable estimates of GPP (R(2) of 0.87 and RMSE of 0.009 kg C m(-2) 8 d(-1) (P < 0.0001)).
湿地生态系统对于生态多样性非常重要，并且具有很强的碳封存能力。通过与野外测量的涡度协方差数据进行比较，我们评估了光能利用率（LUE）指数与增强植被指数（EVI）、归一化差异植被指数（NDVI）和地表温度（LST）之间的关系。因此，我们提出了一种新的模型，用于利用中分辨率成像光谱仪（MODIS）产品估算湿地生态系统的总初级生产力（GPP），这些产品包括植被指数、LST 和被活跃植被吸收的光合有效辐射（FAPAR）分数。该模型是针对中国上海崇明岛的一个研究地点开发和验证的。我们的结果表明，光合有效辐射（PAR）与 LST 高度相关，决定系数（R²）为 0.59（p < 0.001）。植被指数，如 EVI、NDVI 和 LST，与 LUE 高度相关。我们发现，植被指数（VIs）的乘积和 LST 的一种修正形式（Te）可用于估计 LUE，R²为 0.82（P < 0.0001），RMSE 为 0.054 kg C 每 mol PAR。这个新模型可以提供可靠的 GPP 估算值（R²为 0.87，RMSE 为 0.009 kg C m⁻² 8 d⁻¹（P < 0.0001））。
