Freshwater is the most important ecosystem service for human society. Its spatial flows establish the linkage between freshwater sources and human demands, and affect interregional water security. This is called "freshwater services flow" by researchers. A related, more general term, "ecosystem service flow," is often used to describe the transmission of a specific ecosystem service.
A recent research assessing water-related ecosystem services has been done in northeast China by a research team led by Profs. Yu Dapao and Dai Limin from the Institute of Applied Ecology of the Chinese Academy of Sciences.
The Northeast Forest Belt (NFB) covers large land areas of northeast China. With a number of essential ecosystem functions and services, it is vital for the plain areas where populations are concentrated. Considering that natural ecosystems are undergoing degradation worldwide, the researchers wondered whether water security issue had become severer than ever before in northeast China.
They quantified annual water yield and the water demands by agriculture, industry, livestock and residents and developed a dynamic model algorithm to delineate the flow path (i.e., spatial flow process) of freshwater services, which was obviously different from the static model algorithm used by previous studies.
In addition, they also evaluated water security status in northeast China by calculating water security indices based on both static and dynamic flow models.
Although the freshwater resources in northeast China were overall sufficient, the researchers found a downward trend in water security status between 2005 and 2015
Although the freshwater resources in northeast China were overall sufficient, the researchers found a downward trend in water security status between 2005 and 2015, largely because of the changes in precipitation and agricultural water consumption.
By quantifying transboundary flows of freshwater services, the researchers highlighted the importance of upstream watersheds as sources of ecosystem service provision. They also called attention to agricultural and livestock water demands, which may pose a risk of water shortage.
This study may provide technical support for future studies, and its results will be helpful for formulating inter-regional ecological compensation policies, according to the researchers.