Geography Reference
In-Depth Information
Table 2.2
Trends in world crop production along with modelled results of the impact of climate change on productivity.
from the CO
2
fertilisation effect. Potentially
limiting factors include changes in insect life cycles
and an increase in the survival, growth and spread
of pathogens. For example, the frequency of
outbreaks of powdery mildew and rust on crops is
associated with milder mid-latitude winters.
Changes in climatic conditions may also affect
animal agriculture through feed grain availability,
water availability in pasture lands and the
incidence of livestock diseases.
Changing vegetation patterns
While there have been numerous studies of plant
metabolism under enhanced CO
2
, geographers are
rather more interested in the redistribution of
species and biome adjustment to a changing
climatic environment. Webb (1986) has posed the
question as to whether vegetation is in
equilibrium with climate. One method of
assessing the potential for change in the biosphere
has been to study vegetation and lake levels since
the last glaciation. Some idea may then be
obtained of the speed of response of certain
biomes. It is assumed that the dynamics of
Plate 2.2
Forest fires in the Amazon
(photograph:
Panos Pictures).
