Temporal variations in the carbon and nitrogen ecological stoichiometry of lucerne

摘要

Ecological stoichiometry has been of great help in research investigating the coupling between plant and environment (Sterner and Elser 2002). It provides some synchronized evidence to explain the response and adaptability of plants to the environment. Carbon and nitrogen ecological stoichiometry (C/N) also embraces the use efficiency of nitrogen in plants. Previous research has focused on the spatial responses of plant C/N to different environmental factors (Yang and Wang 2011). However, there is still insufficient attention on the temporal variation in C/N, in the hope that such effort will help elucidate the mechanisms underlying plant growth/rcgrowth. Lucerne (Medicago sativa L) has long been globally utilised. It can be cut 3-4 times annually and lasts for many years. The regrowth process in lucerne is of fundamental importance for the continuous utilisation of the forage and the sustainability of lucerne production. In this study, temporal variations in carbon and nitrogen content and C/N were studied in lucerne leaf, stem and root, as part of an effort to clarify the lucerne growth/regrowth mechanisms from the viewpoint of ecological stoichiometry.