User:AimeeByin/Productivity (ecology)


 * Sentences in italics are from the original article.

The productivity of an ecosystem is influenced by a wide range of factors, including nutrient availability, temperature, and water availability. Understanding ecological productivity is vital because it provides insights into how ecosystems function and the extent to which they can support life.

Productivity is typically divided into two categories: primary and secondary productivity.

Primary production is the synthesis of organic material from inorganic molecules.

Aquatic primary productivity refers to the production of organic matter, such as phytoplankton, aquatic plants, and algae, in aquatic ecosystems, which include oceans, lakes, and rivers.

Terrestrial primary productivity refers to the organic matter production that takes place in terrestrial ecosystems such as forests, grasslands, and wetlands.

There are various methods for measuring primary production in ecology. Some of these methods include O2 production (light and dark bottle method), carbon dioxide assimilation, chlorophyll method, harvest method, and radioactive tracers’ method.

Primary production can be divided into gross primary production (GPP), net primary production (NPP), and net ecosystem production (NEP).

Gross primary production measures all carbon assimilated into organic molecules by primary producers.[3]

''Net primary production measures the organic molecules by primary producers. Net primary production also measures the amount of carbon assimilated into organic molecules by primary producers, but does not include organic molecules that are then broken down again by these organism for biological processes such as cellular respiration.[4]'' The formula used to calculate NPP is net primary production = gross primary production - respiration.

Net ecosystem production is defined as the difference between gross primary production (GPP) and ecosystem respiration. The formula to calculate net ecosystem production is NEP = GPP - respiration (by autotrophs) - respiration (by heterotrophs). The key difference between NPP and NEP is that NPP focuses primarily on plant production, whereas NEP incorporates the contributions of other aspects of the ecosystem to the total carbon budget.

Species diversity and productivity relationship:
The connection between plant productivity and biodiversity is a significant topic in ecology, although it has been controversial for decades. Both productivity and species diversity are constricted by other variables such as climate, ecosystem type, and land use intensity.

According to some research on the correlation between plant diversity and ecosystem functioning is that productivity increases as species diversity increases. One reasoning for this is that the likelihood of discovering a highly productive species increases as the number of species initially present in an ecosystem increases.

Other researchers believe that the relationship between species diversity and productivity is unimodal within an ecosystem. A 1999 study on grassland ecosystems in Europe, for example, found that increasing species diversity initially increased productivity but gradually leveled off at intermediate levels of diversity. More recently, a meta-analysis of 44 studies from various ecosystem types observed that the interaction between diversity and production was unimodal in all but one study.

Human interactions:
Anthropogenic activities (human activities) have impacted the productivity and biomass of several ecosystems. Examples of these activities include habitat modification, freshwater consumption, an increase in nutrients due to fertilizers, and many others. Increased nutrients can stimulate an algal bloom in waterbodies, increasing primary production but making the ecosystem less stable. These blooms may provide food for zooplankton and other organisms, resulting in an increase in population density and biomass. This would raise secondary production and have a trophic cascade effect across the food chain, ultimately increasing overall ecosystem productivity.

Overall, human-influenced ecosystems had a rising trend in NPP, whereas wild ecosystems had a declining trend.