to evaluate the relationships between land ownership and terrestrial Landsat NDVI; 2) m MODIS based GPP and NPP; and 3) 30 m Landsat We thank the Google Earth Engine developers for their support and technical advice. The intercept of the relationship between NPP and derived estimates of GPP ( solid line) was significantly lower than the intercept for the relationship between. The amount of energy that plants can trap from the sun is referred to as gross primary production (GPP). An indirect way of measuring this is to measure the.
However, it may over- or underestimate ecosystem GPP with varying climatic conditions and vegetation types because of the algorithm inputs, including the climate input data, the FPAR fraction of photosynthetic active radiation [PAR] absorbed by the canopy and the base rate for light use efficiency Turner et al. Based on the conceptual partitioning of chlorophyll and non-photosynthetic active vegetation NPV within a canopy, Xiao et al.
It has been applied for estimating GPP in forests Wu et al. The enhanced vegetation index EVI, Huete et al. Despite the increasing development of various approaches in assessing ecosystem productivity based on remote sensing data, uncertainty remains on how appropriate a given set of algorithms can be in application to specific ecosystems under specific environmental conditions.ESS 2.3 GPP and NPP
For example, in the grassland ecosystems of North China, different methods have been used to derive productivity based on remote sensing data, e. Globally, the MODIS GPP and VPM algorithm are both recognized for having a great potential for estimating productivity over a wide range of ecosystem types because of their robust performance and general availability of required data sources Running et al.
However, how well the two algorithms compare in application to a fixed site is yet to be tested.
The general conditions of the study area are as described in detail in Jin et al. The vegetation is dominated by Stipa krylovii Roshev.
Mey, Cleistogenes squarrosa Trin. Keng, with minor species including Chenopodium glaucum Linn. The climate is of continental and monsoon type with long-term — mean annual air temperature at 1. Base soils in this region are of calcic—orthic Aridisol Jin et al.
Difference Between NPP and GPP
The study area suffered severe drought in both and The sum of precipitation May to September was only about half of that averaged over the previous 50 years, and the air temperature increased by 1. View large Download slide monthly precipitation and air temperature in and and their departures from the means of the previous 50 years — at the study site of East Ujimuqin of Inner Mongolia, China. For this to occur, a good supply of oxygen must be available to the cell.
The process is called aerobic respiration and it yields between 32 and 38 ATP molecules per glucose molecule broken down. The enzymes and other molecules needed for the latter stages of this reaction are found in small structures within the cytoplasm called mitochondria.
GPP, NPP and respiration
Anaerobic respiration In an animals muscles, the oxygen and ATP reserves may be quickly used up during violent activity. The muscle is able to make more ATP, rapidly by anaerobic means in the absence of adequate oxygen. This happens, for example, when you sprint. Anaerobic repiration is only a partial breakdown of sugars to lactic acid and each molecule of glucose yields only about 2 ATPs.
The lactic acid produced by anaerobic muscle washes to the liver where oxygen is later used to re-process it. The same amount of oxygen is eventually used to totally breakdown the sugar, but by producing lactic acid, the muscle is able to produce more energy locally than would be available by aerobic means. It is often said to have built up an oxygen debt.
Anaerobic respiration in fungi, such as yeast, or in waterlogged plant roots, builds ethanol alcoholCO2 and 3ATPs per molecule of glucose.
This is more toxic than lactic acid, so would not be suitable for muscle cells, which have a much higher need for energy than do plants or fungi.
Ethanol is not re-processed. 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.