Determining tree biomass It is easy to measure the “diameter at breast height” of a tree. It’s hard to measure the total “aboveground biomass” of a tree, because to do this you must cut and weigh the tree.

The biomass is important for studies of ecology, so ecologists commonly estimate it using a power model.

Combining data on 378 trees in tropical rain forests gives this relationship between biomass y measured in kilograms and diameter x measured in centimeters:20 ln y = −2.00 + 2.42 ln x Use this model to estimate the biomass of a tropical tree 30 centimeters in diameter. Show your work.