In areas where the elevation is higher than 4000 m, temperature and precipitation will both decrease with the increase of elevation, so the NPP will decrease. In addition, for the region located in 4000–4500 m, the sensitivity of NPP to elevation is higher than that in the region located above 4500 m.
How will climate change affect NPP?
The effect of temperature change is generally positive to increase the productivity by enhancing the photosynthesis as long as the temperature is in a range of optimum level. When temperature exceeds the optimum level, it will increase the rate of respiration causing the NPP continuously declined.
How does climate change affect oceanic NPP?
Stratification tends to increase in response to ocean sur- face warming and freshening in 21st century climate change simulations. Increased stratification reduces the input of sub- surface nutrients to the euphotic zone and can lead to de- creasing NPP and EP through increasing nutrient limitation.
Is NPP influenced by temperature or precipitation?
A recent paper challenged this consensus, arguing, based on an analysis of NPP for 1247 woody plant communities across global climate gradients, that temperature and precipitation have negligible direct effects on NPP and only perhaps have indirect effects by constraining total stand biomass (Mtot ) and stand age (a).
How does temperature affect GPP and NPP?
However, gross primary productivity (GPP) Q10 averaged 2, indicating that respiration was more severely affected by rising temperature. Furthermore, combined high irradiance and high temperature caused photoinhibition in the laboratory, and resulted in 50% lower NPP at high irradiance.
How does moisture affect NPP?
NPP of arid ecosystem is mostly influenced by water, by enhancing the water use efficiency of vegetation (Xiao et al. 1995). For areas with limited temperature, NPP will get larger when temperature becomes higher (Nemani et al.
How does carbon dioxide affect NPP?
Rising atmospheric carbon dioxide (CO2) and nitrogen (N) deposition increase directly the resource availability to plants, and can increase plant growth and net primary productivity (NPP; Norby et al., 2005).
Why is NPP low in ocean?
The surface of the ocean receives ample light for high rates of photosynthesis (only 5% of the incident light is reflected) and the dissolved CO2 levels are not usually limiting. In open ocean, any dead material sinks to the ocean depths. The warmer, well lit surface layers, therefore, hold little nutrient.
What limits NPP in the open ocean?
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.
Why does the desert have low NPP?
Deserts are areas of low available water. In extreme desert, be it hot or cold, the absence of water will prevent most plants surviving and, hence, productivity is negligible. Plants may show similar adaptations to conserve water in both environments (xerophytism).
Does NPP increase with rainfall?
The results showed that: (1) a 50% reduction in natural precipitation significantly decreased NPP; a 50% increase in precipitation did not significantly increase NPP, but it decreased the importance value of L.
What is 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).
How does latitude affect productivity?
The claim by Huston & Wolverton (2009) that NPP in temperate latitudes is as high or higher than at tropical latitudes is not supported by the data. We instead found a negative relationship between latitude and NPP of forest stands and that productivity of forests is greatest in tropical regions.
How does temperature affect the productivity of photosynthesis?
Although the light dependent reactions of photosynthesis are not affected by changes in temperature, the light independent reactions of photosynthesis are dependent on temperature. They are reactions catalysed by enzymes. … It approximately doubles for every 10 °C increase in temperature.
How does temperature affect GPP?
Within the range of low temperatures in the boreal and temperate regions, GPP increases with temperature faster than RE, which results in an increase of CO2 uptake under climate warming scenarios40.
How does water temperature relate to productivity?
The most likely explanation is that the warmer the surface waters become, the less mixing there is between those waters and deeper, more nutrient-rich water. As nutrients become scarce at the surface, where phytoplankton grow, productivity declines.