The vast majority still unknown to science 但具体数量仍然无人知晓

162. And this recycling happens faster here,
     这种生态循环的速度
163. than anywhere else on the planet.
     比地球上其他地方要快得多
164. There are thought to be nearly a million different types of fungi in the tropics.
     据说热带雨林里有近百万种菌类
165. The vast majority still unknown to science
     但具体数量仍然无人知晓
166. But one thing's for certain
     一点可以确信
167. without fungi, rainforests could not exist.
     没有菌类就没有雨林
168. Nothing goes to waste in the rainforest.
     雨林里的一切都不能浪费

来自《行星地球 第一季 第八集 Planet Earth S01E08 热带雨林》第 165 行