Geography Reference
In-Depth Information
due to the urbanization, but returning cultivated land into forests, etc. in Northeast
China in the past decades led to more significant spatial heterogeneity of cultivated
land that further lead to spatial heterogeneity of impacts of land use on the climate.
4.2.2.3 Implication for the Land use Management
Human activities have contributed to anthropogenic climate change through a
variety of processes, including both of growth or degradation of surface vegetation
and the changes in the land surface; however, impacts of the latter one are not
currently being incorporated into the development of climate change mitigation
policies (Marland et al.
2003
). For example, some previous researches have
quantified the potential of crop management changes to sequester greenhouse
gases, but the biogeophysical effects of most management changes have been less
widely considered (Lobell et al.
2006
). The cultivated land change in Northeast
China is directly caused by the human activities (Deng et al.
2010d
), and the land
use management can exert great influence on the cultivated land change, especially
the conversion between the cultivated land and other land use types, which will
further influence the climate change. The population growth is still the funda-
mental reason for the expansion of cultivated land in Northeast China, and the
economic development and the macro policy are important driving factors of the
land use change. With the rapid economic development and accelerated urbani-
zation, more cultivated land will be converted into urban and built-up land (Deng
et al.
2010a
). Meanwhile, with more attention paid to the environmental protec-
tion, some cultivated lands will also be returned to forests, especially in Northeast
China, where there were once a lot of forests converted into cultivated land due to
the population growth and improper land management. Therefore, there will surely
be more demand for the land resources as the population continually increases and
the economy rapidly develops in Northeast China, which will lead to further land
use change and subsequently exert more influence on the regional climate.
Improved understanding of how human activities influence climate is needed to
guide policies aimed at mitigating or adapting to climate change since the land use
management can exert great influence on the land use change and subsequently
influence the regional climate change (Lehmann
2013
). Over the past several
centuries, human intervention has markedly impacted land surface characteristics
and atmospheric composition in Northern China, in particular through large-scale
land conversion for cultivation and burning of fossil fuels (Sitch et al.
2005
). These
land cover change may play a significant role in driving future climate change
(Lobell et al.
2006
). The land use change in Northern China influences the climate
change through not only the expansion of agriculture into natural ecosystems, but
also the changes occurring within existing cultivated land. For example, historical
clearing of forests for cultivated land is likely to have a cooling effect due to the
greater albedo of croplands relative to forests (Lehmann
2013
). Besides, changes
occurring within existing agricultural lands can also have important consequences
for climate, for example, the increases in irrigation and leaf area index and
