Environmental Engineering Reference
In-Depth Information
The rate of biomass renewal is expressed either as annual productivity (as mass
or energy per unit area) or as overall production (aggregate productivity for a
country, an ecosystem, a biome, or the entire Earth). Specii c productivities of
animals that have traditionally been killed or domesticated for meat, eggs, and dairy
products will be reviewed later; in the next chapter I explain why quantifying
primary productivity is so challenging. I also dei ne all the relevant measures of this
key variable and explain its advantages and limitations in order to avoid misleading
conclusions regarding the human impact on the Earth's biota.
