Stand density index (SDI) was applied as a quantitative index to measure mean crowd degree between trees.

选择林分密度指数(SDI)作为反映林分中林木之间平均拥挤指标。

youdao

Single age variable stock volume growth model had low coefficient of determination, but it was improved a lot by introducing site index and stand density index in reparameterization.

林龄单因变量的蓄积量生长模型决定系数低，引入地位指数和密度指数再次参数化的生长模型可显著提高模型拟合度。

youdao

The ratios of stem, bark and branch biomass to total biomass of stand and individual tree are basically steady in different site index and planting density.

林分和单株的树干、树枝、树皮生物量组成比例均随立地指数、造林密度的变化无明显的差异。

youdao