sue laurance: it's a lot darker in here.t. and we are very coerned about how much aaofore habi? and what we are really saying is how much area of pristine rainforest is left with aorest fragment? and this is very important to tell what species are going to survive in forest fragments. is the core habitat big enough to have more than one individual of this palm species? because some of these species can be very rare -- there could only be one per acre. so do you need to have 50 acres to have 50 individuals? and will that be enough for that population to survive for couple hundred years? narrator: to discover exactly what the effects of fragmentation are onhe rare old-growth tree species in the amazon forest the research team compares plots along forest fragment edges to plots within pristine forest areas. . bill laurance: we have been studying about 65,000 trees for the last 27 years. and overall th's about 1,300 different species of trees. that, just to put it into perspective, is about twice as many scies as occur in all of