NPP is the net carbon gain by plants. It is the balance between the carbon gained by gross primary production (GPP – i.e., net photosynthesis measured at the ecosystem scale) and carbon released by plant mitochondrial respiration, both expressed per unit land area.
What does a high NPP mean?
NPP and ecosystem implications
NPP is the net energy available after respiration. The higher the net primary production, the more animals can be supported per unit area. In most natural ecosystems, high net primary production is generally accompanied by a highly diverse plant and animal community.
What is net primary productivity of an ecosystem?
Net primary productivity, or NPP, is gross primary productivity minus the rate of energy loss to metabolism and maintenance. In other words, it’s the rate at which energy is stored as biomass by plants or other primary producers and made available to the consumers in the ecosystem.
What are GPP and NPP in an ecosystem?
While gross primary production (GPP) is the total influx of carbon into an ecosystem through the photosynthetic fixation of CO2, net primary production (NPP) is this gross carbon influx discounted for plant respiratory costs of growth and maintenance.
What ecosystem has a high NPP?
Tropical rain forests have high NPP and the highest biodiversities of any terrestrial ecosystems. The physical environment favours vast photosynthetic output and high growth rate.
Whats is NPP?
Net primary production (NPP) is strictly defined as the difference between the energy fixed by autotrophs and their respiration, and it is most commonly equated to increments in biomass per unit of land surface and time.
Why is it important to measure NPP?
Why is NPP important? NPP is a measure of plant growth. It provides highly synthesized, quantitative information for sustainable resource management.
How do you calculate NPP?
To calculate NPP, you take the total amount of carbon that the plant fixes (or turns into usable material) and subtract the amount of carbon lost during respiration. The total amount of carbon taken in by the plant is known as the gross primary productivity (GPP), and the amount of respiration is known as Ra.
What biomes have high NPP low NPP Why?
Biomes with more vegetation have higher NPP levels (tropical rainforest has the most). Important because it can be an indicator for studying health of diff plants.
What does negative NPP mean?
Net primary production (NPP)
Values range from -1.0 grammes of carbon per square metre per day (tan) to 6.5 grammes per square metre per day (dark green). A negative value means decomposition or respiration overpowered carbon absorption; more carbon was released to the atmosphere than the plants took in.
Is NPP a GPP?
Gross primary production (GPP) is the total rate at which material is produced and net primary production (NPP) is the rate at which material is accumulated in excess of respiration. In other words, NPP is GPP minus respiration.
Biomass is the living (and sometimes including recently dead) organic material synthesized by plants and other organisms. … Net primary productivity (NPP) represents the difference between gross photosynthesis of plant foliage and energy losses due to respiration and mortality of plant tissues.
How does water affect NPP?
Ecosystem water balance influences several leaf attributes, especially specific leaf area and foliar nitrogen content. … At the larger scale, whole-tree hydraulic conductance and allocation of biomass to root, stem and leaf mass are affected by ecosystem water balance and influence NPP.
What 3 ecosystems have the highest NPP?
In terms of NPP per unit area, the most productive systems are estuaries, swamps and marshes, tropical rain forests, and temperate rain forests (see Figure 4).
What ecosystem has lowest NPP?
The biomes with the lowest levels of primary productivity include deserts, the tundra, the open ocean, and the lakes and streams biome.
What are the four factors important for NPP?
Four principal abiotic factors usually limit the amount of NPP on land – light, water, temperature, and mineral nutrients – and all these abiotic factors are changing rapidly as a result of human activity, with highly uncertain impli- cations for global and local NPP.