New study reveals water constraints on forest photosynthesis

BEIJING, March 7 (Xinhua) -- A new study has revealed that the sunlight-rainfall correlations control the co-occurrence of soil and atmospheric water limitations in forests, according to the Guangdong Academy of Sciences (GDAS).

The study provides a new perspective in understanding water constraints on forest photosynthesis, said Su Yongxian, professor of the Guangzhou Institute of Geography under the GDAS and leader of the study.

Soil water deficit and high atmospheric dryness are major environmental limitations on the carbon uptake of terrestrial ecosystems.

The study was carried out by researchers at home and abroad. It analyzed the impacts of seasonal radiation-rainfall coupling on soil-moisture limitations versus atmospheric dryness limitations on plant photosynthesis across the north of 15 degrees in the Northern Hemisphere, using data from 83 forest sites and satellite-based data.

The results show that soil water availability reduces forest photosynthesis significantly.

The study provides a better understanding of the coupled terrestrial carbon uptakes, energy exchanges, and water transfers.

The study results have been published in the International Journal of Applied Earth Observations and Geoinformation.