Application of HJ-1 CCD data to analyze the growing-season variations of soil respiration in two irrigated cropland ecosystems

摘要

Soil respiration (Rs) is a major CO2 flux within terrestrial ecosystems. This study examine the feasibility of applying HJ-1 CCD data to analyze the growing-season variations of Rs in two irrigated cropland ecosystems. At growing season time scale, crop biophysical parameters, such as leaf chlorophyll content (Chlleaf) and green leaf area index (GLAI), explained most Rs variation in the maize and winter wheat fields. Among the selected vegetation indices from HJ-1 CCD data, enhanced vegetation index (EVI) and green chlorophyll index (CIgreen) showed stronger correlations with Chlleaf for maize or GLAI for winter wheat than normalized difference vegetation index (NDVI). Moreover, for both fields, the relationships between daily mean Rs and either EVI or CIgreen was consistently stronger than the relationship between daily mean Rs and NDVI.