Spatial pattern and uncertainty of soil organic carbon and implications for sampling design

摘要

Woody encroachment has occurred in many arid and semi‐arid ecosystems all over the world ( Archer 1995).Invasion of woody plants into grassland savanna has significant impacts on soil carbon storage and its spatial heterogeneity (Boutton et al.1998).We have limited understanding on the pattern of special heterogeneity and uncertainty of soil carbon and its relationship to the spatial pattern of woody vegetation in savanna landscapes.This understanding is essential for effective assessment and monitoring of soil carbon in savanna landscapes.The goal of this study was to develop an understanding of the spatial pattern and uncertainty of soil organic carbon ( SOC) and how they influence the effectiveness of SOC estimation in subtropical savanna landscapes.The specific objectives were to:(1) quantify the spatial uncertainty of SOC;(2) evaluate the performance of different point sampling designs in estimating SOC storage;and (3) develop effective sampling strategies based on the spatial pattern and uncertainty of SOC.