Bioproduktivitet

Bioproduktivitet is a term used in ecology to describe the rate at which living organisms produce biomass within an ecosystem. It encompasses both primary production, the creation of organic matter by photosynthetic organisms such as plants, algae, and cyanobacteria, and secondary production, the biomass produced by consumers and decomposers. In practice, bioproduktivitet is often expressed as the amount of carbon fixed or biomass formed per unit area per time, such as grams of carbon per square meter per year (g C m^-2 yr^-1).

Primary productivity is commonly described in terms of gross primary production (GPP) and net primary production (NPP). GPP is the total carbon fixed by photosynthesis, while NPP is the portion remaining after autotrophic respiration and available to support growth of plants and higher trophic levels. Ecosystem productivity can also be expressed as net ecosystem production (NEP), which accounts for all gains and losses of carbon in an ecosystem.

Measurement methods include biomass harvests, measurements of soil and plant respiration, eddy covariance techniques, and satellite-based remote sensing. Productivity varies widely among ecosystem types and conditions; forests and algal-dominated systems typically show higher productivity, while deserts, tundra, and nutrient-poor environments are lower. Key drivers include light, temperature, water availability, nutrient supply, atmospheric CO2, and disturbances such as fire or drought, as well as seasonal and geographic variation.

Applications and significance of bioproduktivitet include understanding carbon cycling, climate regulation, and ecosystem services. It informs land management, conservation, and agricultural planning, and is used in climate models to project changes in carbon storage and ecosystem functioning.

Relation to related terms: primary productivity refers specifically to autotrophs, while secondary productivity concerns heterotrophs. Bioproduktivitet is often used broadly to describe ecosystem productivity, though context may distinguish between different components of production.