1.   After years of field work in Tanzania, Klemens decided several years ago to shift his focus to the endangered ecosystems close to his Westchester home.

2.   He said that the South was home to the highest number of endangered ecosystems and was experiencing the sharpest shifts in land use.

3.   How much, for instance, is an endangered ecosystem worth compared with the commercial or industrial development that could replace it?

4.   Our primate cousins are particularly vulnerable because they depend on shrinking tropical forests and endangered ecosystems for foraging.

5.   Scientists consider the Black Sea one of the most endangered ecosystems.