with more forests (being destoryed),huge quantities of good earth (being washed away)each year.
问：
这句话的意思还有时态的运用？

With more forests being destoryed, huge quantities of good earth are washed away each year.

由于更多森林被破坏，每年有大量的好土壤流失掉了。
With ： 可以翻译为由于
With是个介词，基本的意思是“用”，但它也可以协助构成一个极为多采多姿的句型，在句子中起两种作用；副词与形容词。
其中一个结构就是：1.“with+宾语+现在分词或短语”，如：
(1) This article deals with common social ills, with particular attention being paid to vandalism.

huge quantities of good earth are washed away each year.
是主句，因为时间状语是each year,所以用现在时态被动语气。

正常语序如下：
Huge quantities of good earth are washed away each year with more forests being destoryed.