Agriculture Reference
In-Depth Information
20.1 INTRODUCTION
One of the most important ecosystem services for sustainable crop pro-
duction is the mutualistic interaction between plants and animals pollina-
tion. The International community has acknowledged the importance of
a diversity of insect pollinators to support the increased demand for food
brought about by predicted population increases. Changing weather condi-
tion due to increased temperature, erratic rainfall, and enhanced incidence
of diseases are all set to affect the production trend of various vegetable
crops. According to Intergovernmental Panel on Climate Change, it is de-
fined as “Change in climate over time, either due to natural variability or
as a result of human activity.” The most of the warming observed over the
last 50 years is attributable to human activities. The global mean surface
temperature is predicted to increase by 1.4 to 5.8°C from 1990 to 2100. If
temperatures rise by about 2°C over the next 100 years, negative effects
of global warming would begin to extend to most regions of the world
(IPCC, 2001). Developing countries in the tropics will be particularly vul-
nerable. Latitudinal and altitudinal shifts in ecological and agro-economic
zones, land degradation, extreme geophysical events, reduced water avail-
ability, and rise in sea level and salinization are postulated (FAO, 2004).
There are considerable uncertainties about agronomic implications of
vegetable crops. Predicting impact of climate change on vegetable crops
accurately on regional scale is a big problem. Current estimates of chang-
es in climate indicate an increase in global mean annual temperatures of
10°C by 2025, and 30°C by the end of the next century. The date at which
an equivalent doubling of CO will be attained is estimated to between
2025 and 2070, depending on the level of emission of greenhouse gasses
(IPCC, 1990a, b).
20.2 CLIMATE CHANGE, CROP POLLINATION AND
POLLINATORS
Pollination is a vital stage in the reproduction of most flowering plants, and
pollinating animals are essential for transferring genes within and among
populations of wild plant species (Kearns et al., 1998). Although the scien-
tific literature has mainly focused on pollination limitations in wild plants,
in recent years there has been an increasing recognition of the importance
