Desert Ecology

Dr.Abdulhadi Aloufiwww.draloufi.com

The most important elements of climate:

Wind

Rain

TemperatureHumidity

Evaporation

Desert Rain

• Rain is scarce in the desert and limited on a few months of the year. So, the dry season extends for a long period which may cover most of the year, so the plants and animals have special adaptations to resist the shortage of water.

• rains in deserts are its seasonality. irregularity from year to year and from place to place, as well as its falling on a limited area of land where it may fall in a certain regions.

• It also falls in sudden quantities.

Temperature

• In the desert, the temperature has extreme differences between night and day, and between summer and winter.

• The temperature of the surface of the earth (soil) increases during day time while it decreases at night.

• The surface temperature of the soil exceeds that of the land with about 25 degrees and the temperature decreases as the depth increase in the soil.

Humidity

•The humidity of the air is greatly affected by various environmental factors such as the degree of temperature, the wind, direct exposure to sunlight, vegetation cover and water content of the soil.

•The relative humidity decreases during day time with high temperature, while it increases during the night with cooler air

The Wind

• The wind activates the process of transpiration and evaporation, leading to increased water loss from the soil and plant.

• The impact of wind on plants comes through its influence on other climatic factors such as its effect on the relative humidity and temperature through the transfer of masses of hot or cold air from one place to another, as well as the movement of the fog and clouds causing changes of the humidity of the air by mixing dry air with wet air especially in the coastal areas.

The impact of wind on plants:

• The wind and its velocity affects the life of plant directly or indirectly.

– Directly through its impact in the plant itself and in the physiological processes.

– Indirectly through its impact on the environment and other factors which reflect their impact on the plant and its functions.

•Wind can be harmful or beneficial to the plant

Harmful effects of wind on the plant:

•1. Desiccation

•2. Dwarfing3. Deformation4. Breakage5. Abrasion6. Erosion7. Salt Spray