Influence of Climate Changes on Animal Feed Production …
457
(http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch5s5-4-3-1.html),
reviewed the impacts of elevated carbon dioxide in the atmosphere and concluded that nutritional content of forage may decrease when carbon dioxide
concentration increases. That is because of elevated carbon to nitrogen ratios in
the plants themselves and because of the increase in the dominance of unpalatable
grassland species.
These impacts are displayed in several manifestations such as grain yield and
so does the herbage growth [10]. These are positive effects because of the reduced
transpiration, induction of partial closure of stomata, and improved water-use efficiency of some plants [11]. In this case, the more intense management would increase
operating costs and therefore may negate any benefits in forage production.
The increased temperature and carbon dioxide will affect the biodiversity of pasture composition by altering species competition dynamics through the changes
that take place in growth rates [12]. These competitive changes are due to change
the timing and rates of germination and subsequent vegetative and reproductive
development.
The changes in chemical compositions of forage (like nitrogen and water-soluble
carbohydrates) as induced by climatic changes in temperature and dry conditions
will affect the quality of forage to be changed [13]. This author also mentioned that
lignin and cell wall constituents might be altered as the climate temperature increase.
Form and structure of roots, change in leaf growth rate may occur due to extreme
climatic changes like a flood [14]. On the other hand, Craine et al. [15] showed that
measures of forage quality (crude protein and digestible organic matter) declined
with temperature increases and increased when precipitation is increasing.
The changes in forage quantity and quality depend on the region [13, 16]. The
increment of 2 °C will negatively affect pasture and livestock production in arid
and semiarid regions and positively impact the humid temperate regions. However,
the warming has been shown to increase soil water content by accelerating plant
senescence [17].
2.1.4 Effect on Pastures
Pastures depend on rainfall. Any changes in rainfall patterns will affect the plants
on pasture. The other changes in climate will also exert their effects on pastures.
Changes in temporal rainfall distribution will reduce the effectiveness of rain through
the increased variation within and between seasons [18]. As mentioned earlier, the
increased atmospheric temperature will increase the length of the growing season
and, thus, exhaust soil moisture affecting the subsequent pasture growth, especially
in cold areas. In warmer areas, the effect of rising temperature is negative through
the increased evaporation.
In hotter and drier climates, pasture composition may shift to species that could
be less suitable for grazing and so does grazing management to suit the new prevailing conditions. Increased carbon dioxide concentrations will change soil moisture
availability by delaying soil moisture depletion.
457
(http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch5s5-4-3-1.html),
reviewed the impacts of elevated carbon dioxide in the atmosphere and concluded that nutritional content of forage may decrease when carbon dioxide
concentration increases. That is because of elevated carbon to nitrogen ratios in
the plants themselves and because of the increase in the dominance of unpalatable
grassland species.
These impacts are displayed in several manifestations such as grain yield and
so does the herbage growth [10]. These are positive effects because of the reduced
transpiration, induction of partial closure of stomata, and improved water-use efficiency of some plants [11]. In this case, the more intense management would increase
operating costs and therefore may negate any benefits in forage production.
The increased temperature and carbon dioxide will affect the biodiversity of pasture composition by altering species competition dynamics through the changes
that take place in growth rates [12]. These competitive changes are due to change
the timing and rates of germination and subsequent vegetative and reproductive
development.
The changes in chemical compositions of forage (like nitrogen and water-soluble
carbohydrates) as induced by climatic changes in temperature and dry conditions
will affect the quality of forage to be changed [13]. This author also mentioned that
lignin and cell wall constituents might be altered as the climate temperature increase.
Form and structure of roots, change in leaf growth rate may occur due to extreme
climatic changes like a flood [14]. On the other hand, Craine et al. [15] showed that
measures of forage quality (crude protein and digestible organic matter) declined
with temperature increases and increased when precipitation is increasing.
The changes in forage quantity and quality depend on the region [13, 16]. The
increment of 2 °C will negatively affect pasture and livestock production in arid
and semiarid regions and positively impact the humid temperate regions. However,
the warming has been shown to increase soil water content by accelerating plant
senescence [17].
2.1.4 Effect on Pastures
Pastures depend on rainfall. Any changes in rainfall patterns will affect the plants
on pasture. The other changes in climate will also exert their effects on pastures.
Changes in temporal rainfall distribution will reduce the effectiveness of rain through
the increased variation within and between seasons [18]. As mentioned earlier, the
increased atmospheric temperature will increase the length of the growing season
and, thus, exhaust soil moisture affecting the subsequent pasture growth, especially
in cold areas. In warmer areas, the effect of rising temperature is negative through
the increased evaporation.
In hotter and drier climates, pasture composition may shift to species that could
be less suitable for grazing and so does grazing management to suit the new prevailing conditions. Increased carbon dioxide concentrations will change soil moisture
availability by delaying soil moisture depletion.