全球变化知识资源中心

Soil respiration (R-s) in high-altitude areas are normally sensitive to varying climatic conditions. The objective of this research was mainly to explore temporal variations in R-s rates and the corresponding controlling factors for the establishment of appropriate fitting models in a sub-alpine meadow of north China. The data was obtained through field measuring and extraction of the Moderate Resolution Imaging Spectroradiometer (MODIS) in the geographical unit of the study site over the period of 2007 to 2015. The main results were as follows: (1) seasonal variations in R-s rates, soil temperature (T-s), land surface temperature (LST), and normalized difference vegetation index (NDVI) all produced symmetrical bell type patterns, while soil moisture (M-s) showed a fluctuating pattern, (2) a T-s-exponential model could greatly capture seasonal variations of R-s rates in the study site, reflecting the role of temperature as a dominant driving factor in determining R-s temporal variations in alpine meadow areas, (3) there was no significant difference between the performing indicators evaluating the proposed T-s-exponential model and the LST-exponential model. This indicated great potential for applying remote sensing products to estimate seasonal R-s rates and 4) seasonal variations in R-s rates towards temperature sensitivity (Q(10)) showed a concave curve and dramatically decreased as the temperature increased from -1 to 11 degrees C. Overall, the results indicated that attention to significant effects of climatic conditions on R-s, particularly in areas of low temperature, should be warranted. Also, applicability of remote sensing products for estimating R-s was reflected and demonstrated.