Barometer of Life: Sampling

摘要

In their policy forum "the barometer of life" (9 april, p. 177), S. N. Stuart and coauthors report that 160,000 species are required to approach a meaningful indicator of the health of species. Assuming a linear projection, at the current rate of increase and level of investment, this goal will take until 2040. For the barometer to provide trend information (change in status), the 160,000 species assess-rnments will have to be repeated on a regular basis, increasing the time frame for delivery. It is hoped that increased investment and commitment will help accelerate this process, but this will inevitably take many years; the health of the planet's species needs urgently to be better understood.