Forest Influences on Climate and Water Resources at the Landscape to Regional Scale - Landscape Ecology for Sustainable Environment and Culture - page 313

other experimental simulation used hypothetical land covers assuming all crop-
lands, grass lands, and sandy lands are replaced by evergreen needle pine forests—
the major forest type for reforestation in the region. The model operates at a 4 min
time step and 50 km spatial resolution for 10 years.
Simulation results show that afforestation leads to overall increases in precip-
itation, soil moisture and air relative humidity, and decreases in wind speed and air
temperature in the afforested areas. In addition, the results also show significant
influences outside the afforested areas, suggesting a role of afforestation in
changing the climate conditions in surrounding regions.
Simulated precipitation changes as a result of GGW were lumped into six major
areas as outlined (Fig. 15.8 ). Precipitation increases from spring to summer, then
decreases in fall, and decreases further in winter. In each season, precipitation
change is generally the highest in SE, lowest in NW and MO, and in-between in N,
NE, and KO. Precipitation disturbance is positive in all afforestation areas with the
Fig. 15.8 Regional averages of precipitation (mm/day). a-c are control simulation, disturbance
(the difference between experiment and control simulations), and ratio of the difference to
simulation (%). Four seasons are shown from left to right, each with the afforested areas in
Northwest (NW), North (N), and Northeast (NE) China, and the surrounding areas in Southeast
China (SE), Mongolia (NO), and Korea (KO)