Ecosystems In Arid Desert, Speaker Notes

INTRODUCTION

An ecosystem is an area created through the interaction of a community of organisms and their physical environment. It consists of biotic and abiotic factors respectively. The arid desert is one of the ecosystems found in the world today. The characteristics of arid desert ecosystems are presence of little and irregular rainfall averaging 125 mm annually. The area also experiences high periods of draught. Mostly perennial crops grow in the low-lying areas of desert. The arid desert ecosystem covers about 16 percent of the total land surface. Moreover, boundaries are defined by intensity of moisture deficit expressed in terms of the dryness ratio. Arid deserts have the dryness ratio exceeding 0.03. In addition, the arid desert ecosystem is the most challenging physical condition in the terrestrial environment. Wind, temperature and rain form the basic factors for distribution.

Importance

The arid desert ecosystem is home for many animal and plant species. In addition, many organisms live in the desert with each type serving a specific function in the ecosystem. In addition, people use deserts for sporting activities such as racing using off-road vehicles, testing sports cars, and skating. Finally, students the desert ecosystem assists students in their studies through understanding various species living in the desert.

ABIOTIC FACTORS IN ARID DESERT ECOSYSTEM

Arid desert ecosystem contains a variety of abiotic factors. These are sunlight, air, water, temperature, and soil. Temperatures range between 21 and 27 degrees during the day while cool night temperatures go as low as 10 degrees. Cool nights help in precipitation of plants and animals. Soil act as decomposer. Arid desert is characterized by sandy, fine-textured and loose rock fragments. The area also has low salt concentration because of experiencing low rainfall (Simmers, 2005).

BIOTIC FACTORS IN ARID DESERT ECOSYSTEM

The biotic factors found in arid desert ecosystem are divided into plants and animals.

Plants

Plants are the primary producers and include Cacti, Creosote bushes, Thorn acacia, Annual flowers, Rabbit brush, Ocotillo, and Sage brush.

Animals

Animals are the producers and include scorpions, snakes, spiders, lizards, rodents, insects, hawks, and kit fox.

ARID DESERT ECOSYSTEM FOOD WEB

The food web shows different classes of categories that plants and animals fall. Plants are the primary producers who provide food to the primary consumers. Absence of plants in the ecosystem leads to the death of all species. Plant eaters are the primary consumers and include insects, lizards, and rodents (kangaroo and rats). Primary consumers provide food to the secondary consumers like snakes, scorpions, and lizards. At the top of the food chain are the tertiary consumers, also known as large predators. Tertiary consumers depend on other species in the food web for survival.

COMPETITION BETWEEN SPECIES AND NICHE DIVISION

Competition

Species living in any habitat leaves a competitive life. Every organism has a place to live in the universe. Closely related species, such as plants, show ecological similarities. Plants found in the desert show similarities in the method of water conservation and seed dispersal. In addition, all species compete for limited resources. Presence of more food leads to an increase in arid desert population. When more plants grow, primary consumers have plenty of food, and the trend continues to the top of the food web.

Niche Division

Each organism has a place to live in the universe, and the behavior of species living in a given habitat determines its survival. Species living in arid deserts respond differently to distribution of resources and competitors. Plants are the primary producers and their existence determines the survival of all other species in the arid desert. Plants have different modes of survival, for example flowering patterns, deep-rooted roots, and water storage. For example, cacti stores water in their stems. On the other hand, the dispersal ability of a species determines its distribution. Some plants are dispersed by water, wind, or animals that move them to different locations. Animals too have adaptation features. Snakes and lizards are cold-blooded animals hence, can adapt to different temperatures in the desert. In addition, large predators like hawks have unique survival traits allowing them to survive in the desert. The geographical niche and functional niche play a significant role in the survival of species in the arid desert ecosystem.

THREATS AND CONSERVATION EFFORTS FOR ARID DESERT ECOSYSTEM

Threats

Global warming forms the biggest threat to arid desert ecosystems today. A small change in temperature or precipitation affects animals and plants living in the desert. In addition, global warming increases the area under deserts. Moreover, global warming causes increased cases of draughts that results to lack of water for desert habitats. Secondly, high temperatures experienced in the desert may cause wildfires that pose a great threat to plants and animal lives in the desert. Agricultural practices such as irrigation interfere with the soil pH through increasing the base levels threatening plant’s lives. In addition, grazing of animals destroys desert plants. Other practices such as gold mining lead to accumulation of potassium cyanide that poisons wildlife. Moreover, oil and gas extraction disrupts sensitive habitats such as soil micro-organisms. People who sport in deserts using off-road vehicles end up causing much damage to the desert habitat.

CONCLUSION

Environmentalists and other interested bodies put more efforts in the aim of improving arid desert ecosystem and saving the habitats. To start with, these people recommend on the effective use of water resources and quality control of other resources. Additionally, they advise people to develop new ways of rotating crops to prevent the fragile soil, and plant sand-fixing trees. Moreover, planting leguminous plants that extract nitrogen from the air helps restore soil fertility. People using off-road vehicles are advices to use designated tracks. Finally, digging artificial grooves to retain rain water helps solve water problems.