ACKNOWLEDGMENTS
This research was funded by the National Natural Science Foundation of
China (Grant No.41867009) and the National Scientific and Technical
Supporting Programs of China (2006BAC01A01). The authors would like to
express their gratitude to Daqinggou Ecological Station, Institute of
Applied Ecology, Chinese Academy of Science, China.
Abstract: Global climate change and extensive socio-economic
development together decrease ground cover in the semi-arid sandy
grasslands of Horqin district in northern China and thereby increase the
direct exposure of surface soil to erosion by strong winds—a process
that ultimately converts the grassland into a sandy desert. Three ways
to restore such degraded lands through afforestation were evaluated in
terms of total carbon stored in the restored ecosystems compared to that
in the control. Total carbon comprised that stored in the biomass of
trees, herbs, and standing litter and in soil (up to a depth of 100 cm).
The three restoration treatments were (1) enclosing the grassland within
a shelter belt of Populus × beijingensis , (2) afforesting
small but well-distributed patches within the grassland usingPinus sylvestris var. mongolica , and (3) similar
afforestation using Ulmus pumila . Total ecosystem carbon storage
increased significantly in all the three treatments over more than 20
years; at the end of that period, total ecosystem carbon was maximum
(104.29 t/ha) in the grassland enclosed by the forest belt, followed, in
that order, by afforestation with P. sylvestris (102.96 t/ha),
that with U. pumila (92.24 t/ha), and the control (24.48 t/ha).
The structure of the plant community created by these treatments is
different from that found in natural stands of forest and in grasslands
without trees or shrubs, and all the three treatments are suitable for
restoring the moderately desertified sandy grasslands in south-eastern
Horqin, northern China, depending on the availability of water and soil
nutrients.
Keywords: Desertification; sparsely scattered afforestation;
enclosure by tree belts; Ecosystem carbon storage; grassland restoration