Colorado State University

About: Colorado State University is a education organization based out in Fort Collins, Colorado, United States. It is known for research contribution in the topics: Population & Radar. The organization has 31430 authors who have published 69040 publications receiving 2724463 citations. The organization is also known as: CSU & Colorado Agricultural College.

Temperature and soil organic matter decomposition rates – synthesis of current knowledge and a way forward

Abstract: The response of soil organic matter (OM) decomposition to increasing temperature is a critical aspect of ecosystem responses to global change The impacts of climate warming on decomposition dynamics have not been resolved due to apparently contradictory results from field and lab experiments, most of which has focused on labile carbon with short turnover times But the majority of total soil carbon stocks are comprised of organic carbon with turnover times of decades to centuries Understanding the response of these carbon pools to climate change is essential for forecasting longer-term changes in soil carbon storage Herein, we briefly synthesize information from recent studies that have been conducted using a wide variety of approaches In our effort to understand research to-date, we derive a new conceptual model that explicitly identifies the processes controlling soil OM availability for decomposition and allows a more explicit description of the factors regulating OM decomposition under different circumstances It explicitly defines resistance of soil OM to decomposition as being due either to its chemical conformation (quality )o r its physico-chemical protection from decomposition The former is embodied in the depolymerization process, the latter by adsorption/desorption and aggregate turnover We hypothesize a strong role for variation in temperature sensitivity as a function of reaction rates for both We conclude that important advances in understanding the temperature response of the processes that control substrate availability, depolymerization, microbial efficiency, and enzyme production will be needed to predict the fate of soil carbon stocks in a warmer world

A Revised Land Surface Parameterization (SiB2) for Atmospheric GCMS. Part II: The Generation of Global Fields of Terrestrial Biophysical Parameters from Satellite Data

Abstract: The global parameter fields used in the revised Simple Biosphere Model (SiB2) of Sellers et al. are reviewed. The most important innovation over the earlier SiB1 parameter set of Dorman and Sellers is the use of satellite data to specify the time-varying phonological properties of FPAR, leaf area index. and canopy greenness fraction. This was done by processing a monthly 1° by 1° normalized difference vegetation index (NDVI) dataset obtained farm Advanced Very High Resolution Radiometer red and near-infrared data. Corrections were applied to the source NDVI dataset to account for (i) obvious anomalies in the data time series, (ii) the effect of variations in solar zenith angle, (iii) data dropouts in cold regions where a temperature threshold procedure designed to screen for clouds also eliminated cold land surface points, and (iv) persistent cloud cover in the Tropics. An outline of the procedures for calculating the land surface parameters from the corrected NDVI dataset is given, and a brief d...