Question: Where Is Productivity Highest?

What do you mean by net primary productivity?

They show net primary productivity, which is how much carbon dioxide vegetation takes in during photosynthesis minus how much carbon dioxide the plants release during respiration (metabolizing sugars and starches for energy).


Where is ocean productivity highest?

Higher chlorophyll concentrations and in general higher productivity are observed on the equator, along the coasts (especially eastern margins), and in the high latitude ocean (Figure 4a and b).

What is primary productivity in the ocean?

Primary productivity is the rate at which atmospheric or aqueous carbon dioxide is converted by autotrophs (primary producers) to organic material. Primary production via photosynthesis is a key process within the ecosystem, as the producers form the base of the entire food web, both on land and in the oceans.

Which ocean zone is lacking in nutrients?

abyssal zoneThe deepest part of the ocean, the abyssal zone, at depths of 4000 m or greater, is very cold and has very high pressure, high oxygen content, and low nutrient content. There are a variety of invertebrates and fishes found in this zone, but the abyssal zone does not have plants due to the lack of light.

What 3 ecosystems have the lowest productivity?

The smallest land areas are occupied by tundra and temperate grassland ecosystems, and the largest land area is occupied by tropical forest. The most productive ecosystems are temperate and tropical forests, and the least productive are deserts and tundras.

How does high productivity influence the food chain?

In this way, energy is made available to higher trophic levels in food chains and food webs. … Since consumers depend directly or indirectly on the energy captured by primary producers, the productivity of an ecosystem affects all trophic levels.

How do humans affect net primary productivity?

Human activities such as land use affect the magnitude of global NPP and the flow of biomass through ecosystems, among others through changes in land cover. … Results showed that humans appropriated 23.8% of NPP in 2000, 15.6 billion metric tonnes of carbon per year.

Where in the ocean is productivity high at the surface Why?

In the fall as the surface waters cool off, they begin to mix with the waters beneath them, and this mixing, with the help of winter storms, stirs up nutrients. So the ocean is more productive in temperate zones. This also explains why the tropics have that pretty clear blue water.

What is net primary productivity and why is it important?

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.

How does temperature affect primary productivity?

Increasing temperatures may affect macroalgal assemblages in three ways: 1) higher respiration rates can change the ratio of photosynthesis to respiration, decreasing long-term net primary productivity; 2) the combination of high temperature and high irradiance may increase photoinhibition, thereby decreasing NPP …

How do you find net primary productivity?

You can see that your bank account balance is determined as follows: Your Net production is equal to your Gross Production minus Respiration, which is the same as the equation above that states the Net Primary Production (NPP) = the Gross Primary Production (GPP) minus Respiration (R).

What is primary and secondary productivity?

The productivity of autotrophs, such as plants, is called primary productivity, while the productivity of heterotrophs, such as animals, is called secondary productivity. …

Why is open ocean so low in productivity?

Because of the density difference between surface water and the deep sea across most of the ocean, ocean circulation can only very slowly reintroduce dissolved nutrients to the euphotic zone. By driving nutrients out of the sunlit, buoyant surface waters, ocean productivity effectively limits itself.

Where is primary productivity highest?

The highest net primary productivity in terrestrial environments occurs in swamps and marshes and tropical rainforests; the lowest occurs in deserts.

Which ocean zone has the lowest productivity?

Red end of spectrum is highest productivity, blue/violet end is lowest. The overall pattern with latitude is clearly visible: low productivity in the tropics and subtropics, probably due to nutrient limitation brought about by strong, year-round thermocline and pycnocline.

What is the main reason for low productivity of ocean?

In ocean, sunlight is the main limiting factor which decreases the rate of photosynthesis. Decrease in rate of photosynthesis decreases the growth of aquatic plants and animals.

Which ocean zone has the most available nutrients?

Consequently, cold deep ocean water is often much higher in essential mineral nutrients than surface waters where primary production depletes them.

What increases net primary productivity?

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.