Spatiotemporal Variation Characteristics of Vegetative PUE in China from 2000 to 2015

Abstract EN

Vegetative precipitation-use efficiency (PUE) is a key indicator for evaluating the dynamic response of vegetation productivity to the spatiotemporal variation in precipitation.

It is also an important indicator for reflecting the relationship between the water and carbon cycles in a vegetation ecosystem.

This paper uses data from MODIS Net Primary Production (NPP) and China’s spatial interpolation data for precipitation from 2000 to 2015 to calculate the annual value, multiyear mean value, interannual standard deviation, and interannual linear trend of Chinese terrestrial vegetative PUE over the past 16 years.

Based on seven major administrative regions, eleven vegetation types, and four climate zones, we analyzed the spatiotemporal variation characteristics of China’s vegetative PUE.

The research results are shown as follows: (1) China’s vegetative PUE shows obvious spatial variation characteristics, and it is relatively stable interannually, with an overall slight increasing trend, especially in Northwest and Southwest China.

The vegetative PUE is higher, and its stability is declined in Xinjiang, western Gansu, and the southern Tibetan valley.

The vegetative PUE is lower, and its stability is increased in northeastern Tibet and southwestern Qinghai.

An increasing trend in vegetative PUE is obvious at the edge of the Tarim Basin, in western Gansu, the southern Tibetan valley, and northwestern Yunnan.

(2) There is a significant difference in the PUEs among different vegetation types.

The average PUE of Broadleaf Forest is the highest, and the average PUE of Alpine Vegetation is the lowest.

The stability of the PUE of Mixed Coniferous and Broadleaf Forest is declined, and the stability of the PUE of Alpine Vegetation is increased.

The increasing speed of the PUE of Grass-forb Community is the fastest, and the decreasing speed of the PUE of Swamp is the fastest.

(3) There is a significant difference in the PUEs among different vegetation types in the same climate zone, the difference in vegetative PUE in arid and semiarid regions is mainly affected by precipitation, and the difference in vegetative PUE in humid and semihumid regions is mainly affected by soil factors.

The PUEs of the same vegetation type are significantly different among climate zones.

The average PUE of Cultural Vegetation has the largest difference, the stability of the PUE of Steppe has the largest difference, and the increasing speed of the PUE of Swamp has the largest difference.