About 40 to 85 percent of gross primary productivity is not used during respiration and becomes net primary productivity. The highest net primary productivity in terrestrial environments occurs in swamps and marshes and tropical rainforests; the lowest occurs in deserts.
Why do some ecosystems have higher NPP than others?
Production forests are comparatively stable ecosystems, experiencing a longer growth cycle than food and energy crops. Food and energy crops are usually harvested at the end of a relatively short rapid growth phase, leading to a higher average NPP per unit area.
How do ecosystems affect NPP?
Ecosystem water balance influences NPP through effects at several scales. … Respiration rates and the relative contributions of root, stem and leaf respiration vary with ecosystem water balance and therefore influence NPP.
Why does NPP increase?
Plant communities will assemble during early succession, with fast-growing plants emerging first and because of low initial plant density there will be little competition for resources. As a result, total plant growth in the ecosystem, or NPP, will proceed at an increasingly higher rate for several years.
What does a higher NPP mean?
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.
Why do tropical rainforests have high NPP?
Net Primary Productivity is affected by temperature, water availability, carbon dioxide, and nutrients, all of which are abiotic factors. In Tropical Rainforests, water, sunlight, and high temperatures are consistent and a dense concentration of plants is present, causing both the GPP and NPP to be very high.
Why does the NPP increase over time as the plants grow and mature )?
the NPP will increase over time because plants undergo metabolic process which increase the # of cells and cell products which can be used as energy for the next trophic level.
Why is NPP important to ecologists?
NPP is an important component of the global carbon budget and is used as an indicator of ecosystem function. NPP can be directly assessed by measuring plant traits or harvesting plant material on the ground, but across large areas remotely sensed images can be used to estimate NPP.
Why do rainforests and estuaries have such high NPP Why should they be protected?
Why do you think tropical rain forests and marshes have high NPP? Why should these areas be protected? There is a lot of water for photosynthesis production. Tropical rain forests and marshes help sustain life.
What factors affect NPP?
Net primary productivity varies among ecosystems and depends on many factors. These include solar energy input, temperature and moisture levels, carbon dioxide levels, nutrient availability, and community interactions (e.g., grazing by herbivores) 2.
What biome has the highest NPP?
Tropical forests have the highest biodiversity and primary productivity of any of the terrestrial biomes. Net primary productivity ranges from 2–3 kg m–2 y–1 or higher.
Which terrestrial ecosystem has the highest NPP?
The highest net primary productivity in terrestrial environments occurs in swamps and marshes and tropical rainforests; the lowest occurs in deserts.
Why are ecologists usually more concerned with net primary productivity rather than gross primary productivity?
Why is net primary production (NPP) a more useful measurement to an ecosystem ecologist than gross primary production (GPP)? A) NPP can be expressed in energy/unit of area/unit of time. … NPP can be expressed in terms of carbon fixed by photosynthesis for an entire ecosystem.
Which 3 ecosystems have the highest productivity?
The world’s ecosystems vary tremendously in productivity, as illustrated in the following figures. 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).
Can NPP be higher than GPP?
d. NPP will always be a smaller number than GPP and will therefore be a conservative measure of how many heterotrophic organisms can be expected to be supported in an ecosystem.
What is similar about the ecosystem that makes up a biome?
A grouping of ecosystems with similar abiotic and biotic conditions. Average conditions, temperature and precipitation over long periods of time in a given area.