Carbon, Nitrogen and Natural Abundance of δ13C in Forest Cover

ABSTRACT The aim of this study was to evaluate and compare the density (Ds) and content of carbon (C) and nitrogen (N), carbon (Cstock) and nitrogen stock (Nstock), and the natural abundance of δ13C in the soil profile of an area of Semideciduous Forest (SF) converted to eucalyptus monoculture (Corymbia citriodora) (ERN) in order to elucidate the changes in these environments. For this purpose, soil samples were collected at depths up to one meter in each study area. The conversion of FES to monocultures reduced Ds, N and EstC in the surface layer. However, there was an increase in EstC in the deeper soil layers. The δ13C isotopic signal of the vegetation that once occupied areas of C. citriodora plantation was similar to that currently found in the area of SF, and the time of conversion was at the depth of 0,40 m in the soil profile.

摘要
本研究旨在评估并对比半落叶林（Semideciduous Forest, SF）转换为柠檬桉（Corymbia citriodora）纯林（ERN）区域的土壤剖面中，土壤密度（Ds）、碳（C）与氮（N）含量、碳库（Cstock）与氮库（Nstock），以及δ¹³C的自然丰度，以阐明两类生境的环境变化特征。为此，本研究在各研究区域内采集了深度达1米的土壤样品。将半落叶林转换为纯林后，表层土壤的Ds、N及EstC均有所降低，但深层土壤的EstC则出现升高。曾占据柠檬桉人工林区域的植被的δ¹³C同位素信号，与当前半落叶林区域的δ¹³C信号相似，且土地利用转换事件对应的土壤剖面深度为0.40米。