Vegetation that has evolved in an area over time.

Plant biomass gain measured in tonnes of carbon per hectare per year, as a product of the energy gained through photosynthesis minus the energy lost through respiration. It is an indicator of the natural agricultural productivity of an area, based on its climate.

Resources that cannot be renewed, for example, minerals. Soils that have been degraded can only be renewed over long timescales. Also see environmental resources.

Recycling of plant nutrients like phosphorus and nitrogen, whether by natural means or human intervention.