对云南西双版纳割胶、未割胶条件下橡胶林土壤有机碳动态变化特征及其不同保护带种植方式(距瓣豆绿肥覆盖与野生杂草覆盖)的响应研究表明,不同管理方式下橡胶林土壤有机碳含量呈现明显的动态变化,种植距瓣豆绿肥覆盖与野生杂草生长覆盖的橡胶林土壤有机碳变化趋势一致。随时间变化橡胶林土壤有机碳含量呈现先升高、后下降的变化趋势,土壤有机碳含量具有表层(0~20 cm)>中层(20~40 cm)和底层(40~60 c
In the democratic and constitutional system the power of the word ofthe law originates from people's sovereignty. The legal paper, based on ademocratic mandate,
To sample non-bandlimited impulse signals, an extremely high-sampling rate analog-to-digital converters (ADC) is required. Such an ADC is very difficult to be i