Simulation of the Plausible Climate Effects of Ecological Restoration Programs in China - Land Use Impacts on Climate - page 139

Table 5.1 Simulated effects of afforestation on the monthly average temperature in Jiangxi
Province (measured in degrees Celsius)
Month DB DN EB EN

Mean Std. Mean Std. Mean Std. Mean Std.

Jan -0.12 0.09 -0.06 0.06 0.05 0.06 0.03 0.05

Feb -0.09 0.07 -0.05 0.06 0.03 0.05 0.02 0.05

Mar -0.07 0.07 0.00 0.05 0.05 0.05 0.02 0.05

Apr -0.07 0.06 -0.03 0.05 0.02 0.04 0.01 0.04

May -0.08 0.07 -0.02 0.05 0.01 0.05 -0.01 0.05

Jun -0.08 0.08 -0.03 0.06 0.01 0.06 0.00 0.06

Jul -0.05 0.08 -0.02 0.07 0.00 0.07 -0.01 0.07

Aug -0.06 0.08 -0.01 0.07 0.00 0.06 -0.01 0.07

Sep -0.08 0.08 -0.03 0.06 0.00 0.06 -0.01 0.06

Oct -0.07 0.06 -0.01 0.04 0.03 0.04 0.01 0.04

Nov -0.08 0.07 0.00 0.06 0.05 0.06 0.02 0.05

Dec -0.07 0.07 0.00 0.05 0.05 0.06 0.03 0.05

of EB and EN, respectively. On the whole, the deciduous forest expansion may
aggravate the drought, while the expansion of evergreen forests may increase the
annual average precipitation in most of the regions in Jiangxi Province. So the
expansion of evergreen forests is more favorable than the expansion of deciduous
forests since the seasonal drought is one of the main problems that restrain the
agricultural production in Jiangxi Province.

5.1.2.3 Effects on the Monthly Climate

The effects of afforestation on the monthly average temperature vary from month to
month under all the four scenarios (Table 5.1 ). Under the scenario of DB, the
deciduous broadleaf forest expansion will result in a relatively stable decrease of the
monthly average temperature in most of the months, by about 0.07-0.08 C, and it
will decrease most in January and least in July, by about 0.12 and 0.05 C, respec-
tively. By comparison, there is a slighter decrease of the monthly average temper-
ature due to the deciduous needleleaf forest expansion under the scenario of DN than
that of under the scenario of DB, moreover, it will decrease by no more than 0.03 C
from April to October. The afforestation even has no effects on monthly average
temperature in March, November, and December under the scenario of DN.
In contrast to the effects under the scenarios of DB and DN, the evergreen
broadleaf forest expansion will lead to some increase of the monthly average
temperature (Table 5.1 ). The simulation results show that the monthly average
temperature will increase by 0.03-0.05 C from October to March under this
scenario, and it will decrease by 0.01-0.02 C in April, May, and June. Besides,
there are no significant effects of the evergreen broadleaf forest expansion on the
monthly average temperature in July, August, and September. There are more