Download Potential Impacts of Global Climate Change to Biodiversity in

Potential Impacts of Global Climate Change to Biodiversity in
Anambra State, Nigeria.
Climate change has become one of the prime issues threatening the sustainability
of worlds’ environment. Besides environment, climate change also has impacts on
biodiversity, health and economy of the globe (Sharma, 1975).
Changes in Earths’ climate is as result of both natural and human factor. Before
humans, changes in climate resulted entirely from natural causes such as changes
in Earth’s orbit, changes in solar activity, or volcanic eruptions. Since the
Industrial Era began, humans have had an increasing effect on climate, particularly
by adding billions of tons of heat-trapping greenhouse gases to the atmosphere.
Most of the observed warming since the mid-20th century is due to human-caused
greenhouse gas emissions.
There are a number of components of global environmental change which are
largely ecological changes and all have important ecological consequences. Three
of the well documented global changes are
 increasing concentrations of carbon dioxide in the atmosphere
 alterations in the biogeochemistry of the global nitrogen cycle
 ongoing land use/ land cover change.
Human activity – now fossil fuel combustion has increased carbon dioxide
concentration. This increase is likely to have climatic consequences and certainly it
has direct effects on biota in all Earths’ terrestrial ecosystems.
The global nitrogen cycle has been altered by human activity to such an extent that
more nitrogen is fixed annually by humanity (primarily from nitrogen fertilizer,
legume crops and as byproduct of fossil fuel combustion) than by all natural
pathway combined. This added nitrogen alters the chemistry of the atmosphere and
of aquatic ecosystems, contributes to eutrophication of the biosphere, and has
sustainantial regional effects on biological diversity in the most affected areas.
Finally, human land use/ land cover change has transformed one- third to one half
of Earths’ crust. This in and of itself probably represents the most important
component of global change now and will for some decades to come; it has
profound effects on biological diversity on land and on ecosystems downwind and
downstream of affected areas (Vitousek, 1993).
In Anambra state, the most important feature observed is the almost complete
absence of primary forests. Uncontrolled logging and agricultural activities, acid
rain, urbanization and quarrying activities have contributed to loss of vegetation.
The changes in vegetation will have great implication on biological productivity
and it will affect biomass production. It will lead to the impoverishment of
biodiversity and various plant species which at present grow in the region may die
off.
To this effect, the objectives of this study are to
Materials and Methods
The Study Area
Data Collection
1. Data will be collected from Ministry of Agriculture, Ministry of
Environment and Meterological stations.
2. Data on rainfall, temperature, relative humidity, evapouration and sunshine
duration for a period of 10 – 20 years.
3. Collect soil data.
4. Prepare species inventory
Expected outcome
Plants that do respond to elevated carbon dioxide produce tissue with lower
nutrient concentration (that is plants with the C3 photosynthetic pathway will gain
than plants with the C4 photosynthetic pathway ( Bazzaz 1990, Pooter 1993). As a
consequence, the individual herbivores must consume more tissue to acquire
sufficient protein and other nutrients for growth and development (Fajer et al.
1991, Field et al. 1989), they generally grow more slowly and suffer higher
mortality in the process ( Fajer et al. 1989). Similarly, decomposers may encounter
lower quality tissue, with consequences for their own populations and for
ecosystem level nutrient cycling (Norby et al. 1986).
Additions of nitrogen can be expected to affect consumers, decomposers and
symbionts as well as plants. Increases in nitrogen concentrations in plant tissue
favour the growth and survival of many consumers (Mattson 1980, Field et al.
1992) and can affect populations of predators and parasites as well (Loader and
Damman 1991).
The tissue produced by N- fertilized plants often decomposes and releases nutrients
more rapidly than that of conspecific unfertilized plants (Vitousek 1983, Berg et al.
1987).
For symbionts, added nitrogen would be expected to decrease the activity of
nitrogen fixing organisms, as externally supplied N can replace energetically costly
fixed N in plant metabolism (Arnolds 1991).
Land use change can affect climate both locally and regionally by altering the ways
that solar energy is partitioned. Conversion of forest to pasture increases albedo
and decreases canopy roughness on a local scale, the net effect is an increase in
local temperature and a decrease in humidity; these in turn can affect the potential
for forest regeneration (Uhl and Kauffman, 1990).
Changes in rainfall can affect soil erosion rates and soil moisture, both of which
are important to plants and crop yields. Rainfall amount and timing influences the
yield of crops . low rainfall amounts can be detrimental to crop yields, especially if
dry periods occur during critical development stages (Owusu, et al. 2012) rainfall
increase affects crop yield positively by readily dissolving the nutrients for easy
soil absorption by plants (Rosenzweig et al 1995).
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