All these influences have a negative impact on the spirit bear’s very existence, which is made all the more fragile by the fact that reproduction among these bears has always been disappointingly low.
这是我自己翻译的但是觉得不太对也不流畅:
所有这些影响对于白灵熊的生存来说都是负面影响,事实上造成了白灵熊更脆弱——这些熊的繁殖率总是令人失望地低。
还有very修饰existence这是怎么个讲法,还有the white bear relies on the huge centuries--old growth trees in the forest in many ways.这里的huge用来修饰century感觉也是很怪啊。怎么理解啊?
翻译整句的意思是:白灵熊依伏古老高大的树林里生活,但由于受到年代影响所产生的负面影响,这所有影响都会使这些白熊的生存更加脆弱,一直处于灭绝的边缘,这些熊的繁殖率总是让人失望至极。