Structure and Functions of Desert Ecosystms

DESERT ECOSYSTEM

Introduction

v     A desert is a landscape or region that receives almost no precipitation.

^v   Deserts are defined as areas with an average annual precipitation of less than 250 millimeters per year.

^v   It occupies about 17% of the earth’s surface.

^v   Deserts are characterized by hot days & cold nights.

^v   The deserts of the world are mainly located in the

South- western United States, Mexico, North

America, Asia      (Thar, Gobi, Tibet) & west Asia.

^v   Deserts are characterized by scanty flora & fauna.

^v   Soils of deserts often have abundant nutrients but little or no organic matter.

Sturucture and Functions of Desert Ecosystms

I. Biotic components

1) Producer Organisms

^v   In a desert, producers are mainly shrubs/bushes; some grasses & a few trees.

^v Dominant plant species include: Succulents (water - retaining plants adapted to arid climate or soil conditions) & hardy grasses.

^v   Besides some lower plants such as lichens & xerophytic mosses are also present.

2) Consumer Organisms

These include animals such as insects, reptiles which are capable of living in xeric conditions

^v Besides some nocturnal rodents, birds & some mammalians like camel etc are also found.

3) Decomposers

Due to poor vegetation with very low amount of dead organic matter, decomposers are poor in desert ecosystem.

^v   The common decomposers are some bacteria & fungi, most of which are thermophillic.

II. Abiotic components

Due to high temperature & very low rainfall, the organic substances are poorly present in the soil.