Geoscience Reference
In-Depth Information
celebrate the 'International Day for Biodiversity' on 22nd May,
2007, under the theme 'Climate change and biodiversity'.
Direct impacts
of climate
change on
biodiversity
A shift in distribution of the biotic community
If climatic
factors such as temperature and precipitation are changed in
such a way that certain species' phenotypic plasticity find it
beyond tolerance, the obvious outcome will be its shift in natu-
ral distribution. This results in migration of the species or com-
munity to other habitats responding to the changing conditions.
Vegetation zones may move toward higher latitudes or higher
altitudes following the change in average temperature. The cur-
rent migration rate of a species has been falling day by day as
compared to that of the past and, thus, a drastic increase in
extinction cases. In addition to altering species' distribution,
the rapid pace of the current climate change has decreased the
ability of some species to follow the climate to which they are
adapted. Storm petrel (
Hydrobates pelagicus
) is the smallest
Atlantic seabird, which migrates from its breeding grounds in
the North Atlantic to Namibia, South Africa and the Indian
Ocean. Migrating birds must build up and maintain large fat
reserve to fuel their migration journeys. Climate change affects
their fat reserve by altering the conditions along their migra-
tion rate. This bird feeds upon zooplankton for its fat reserve.
Researchers found that the abundance of zooplankton has
deceased as a result of change in sea temperature and chemi-
cal composition, which ultimately results in reduction of body
mass of the migrating bird. Rates of climate change and species
adaptation vary at regional and even local levels and they are
of great importance. The maximum rates of spread for some
sedentary species including large tree species may be slower
than the predicted rates of change in climate conditions. This is
likely to lead to localised extinction of these species.
Interaction among species
Different species respond differ-
ently to a changed condition. Certain species may easily adapt
to a new condition while some others may face difficulties in
adapting. This difference in sensitivity toward the changing
condition will give rise to complex species interaction resulting
in further complications.
Invasive species
From historic times, new animals and plants
are being introduced from one part of the world to the other by
humans. Newly introduced species may act invasive, affecting
the native inhabitant of the area by eating them, hybridising
with them, competing with them or by introducing pathogens
