From Bruce Denness, Whitwell, Isle of Wight, UK
Sarab Sethi and his team have developed a device that cheaply gauges rainforest biodiversity by interpreting the collective sound of different animals (6 October, p 10). I predict the results will reflect ““.
This arose from efforts to maximise crops and is also called the “-3/2 distribution law”: if you chart the mean weight of plants against their number per unit area on a double-logarithmic plot, you get a straight line with a downward slope of –3/2. This quantifies the observation that the more plants are crowded, the smaller each is liable to be.
The finding was later extended to the distribution densities of animals and birds – and described as a law in search of a theory (). It should help in defining the area required to protect species. For instance, predatory birds require more territory than predatory mammals, followed by herbivorous birds, primates and herbivorous mammals.
Advertisement
