he was amazed to find that some citise on cutting the trees

不可以.
whichr指的是some citise on cutting the trees .你换成and,意思就变了,变成some cities 在破坏环境了.
另外,您这句子好象不太顺,destroy打错了,应该是are吧.
再问： he was amazed to find that some citise kept on cutting the trees which distoryed the environment . 应该是这样
再答： kept on，ok，这样就对了。 解释不变，仍然是上面的。