you gothese big fore palm trs, and the forest understory is just generally lot sparser now. we don't have that profusion of vines, and we have got a lot of these sde-loving plants, which can't survive on the harsh forest edge we call thisnvironment in here the core of t habitatragment. and we are very coerned about how much area ofore habitat do we have? and what we are really saying is how much area of pristine rainforest is left th 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 fothat 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 ars. . bill laurance: we