Desert Ecology

DESERT ECOSYSTEM: 

DESERT ECOSYSTEM PREVIEW INTRODUCTION TO ECOLOGY AND ECOSYSTEM DESERT ECOSYSTEMS AROUND THE WORLD WHAT IS A DESERT? TYPES OF DESERTS MEMBERS OF THE DESERT FOODCHAIN PRODUCERS CONSUMERS DECOMPOSERS IMPACT OF HUMANS ON DESERT ECOSYSTEM

WHAT IS AN ECOSYSTEM?: 

“An ecosystem is a community of living organisms interacting with one another and with the non-living physical and chemical environment. The interactions are such as to perpetuate the community and to retain a large degree of stability under varying conditions.” The members of any given ecosystem are grossly classified into three categories as shown: WHAT IS AN ECOSYSTEM?

DIFFERENCE BETWEEN ECOLOGY AND ECOSYSTEM: 

Ecology is the science that studies the relationships between living things and their environment. It is the branch of biology that studies the structure and functions of nature. Ecosystem is short for ecological system. It comprises of plants and animals sharing the same environment. A puddle of water, bushes or a large desert-all are ecosystems. DIFFERENCE BETWEEN ECOLOGY AND ECOSYSTEM

DESERT ECOSYSTEMS AROUND THE WORLD: 

DESERT ECOSYSTEMS AROUND THE WORLD

WHAT IS A DESERT?: 

A desert is a landscape or region that receives an extremely low amount of precipitation , less than enough to support growth of most plants. Deserts are defined as areas with an average annual precipitation of less than 250 millimetres per year. Deserts are located where vegetation cover is sparse to almost nonexistent. Water vapour in the atmosphere acts to trap infrared radiation from both the sun and the ground, but dry desert air is incapable of blocking sunlight during the day or trapping heat during the night. Thus, during daylight most of the sun 's heat reaches the ground, and as soon as the sun sets the desert cools quickly by radiating its heat into space. WHAT IS A DESERT ?

PowerPoint Presentation: 

Desert-An ecosystem formed where there is very little rainfall. Two kinds of deserts: Hot deserts Cold deserts Hot deserts Temperatures are very warm all year round The summers are very hot Cold deserts Short, warm summers Long, cold winters Found in places near the north and south poles

MEMBERS OF THE DESERT FOODCHAIN: 

MEMBERS OF THE DESERT FOODCHAIN PRODUCERS PRIMARY CONSUMERS TERTIARY CONSUMERS SECONDARY CONSUMERS DECOMPOSERS

PRODUCERS: 

Producers include photosynthetic plants that have adapted to desert conditions. Most desert plants are drought- or salt-tolerant. Some store water in their leaves, roots, and stems. E.g. the saguaro cactus can expand its stem to store water. Other desert plants have long taproots that penetrate to the deep water tables or widely spread shallow and spongy roots. Some plants have thorns or toxins to protect themselves from animals. Some plants have wax coated leaves to minimize the moisture loss. The giant saguaro cacti also provides nests for desert birds and serve as "trees" of the desert. Saguaro Cactus PRODUCERS

CONSUMERS: 

CONSUMERS Consumers are heterotrophs like reptiles, rodents, insects, birds and mammals. Desert mammals can be divided into four broad categories: the carnivores (meat eaters), small and large herbivores (plant eaters), and insectivores (insect eaters). Reptiles are classified into snakes and lizards. All must conform to specific behavioural traits to survive in such arid lands. Most desert mammals are nocturnal, which means active during the night. E.g. Rattlesnakes, kangaroo rats, and kit foxes. Temperatures are lower and humidity is higher then and the animal loses less water through perspiration and breathing.

ROLE OF A CONSUMER: 

In a mammal, such as the desert pocket mouse, food is consumed and converted to energy. The mouse, being warm-blooded, uses this energy in several ways. 1. The mouse receives stored energy by eating food. 2. The mouse's metabolism converts stored energy from the food to available energy for it's survival. To survive the mouse needs to grow, acquire more food, escape predators, etc). Some energy is lost to heat, but this heat can be helpful to keep the mouse's body at a normal temperature in cold weather. 3. Some energy is lost in the production and passing of waste as unprocessed nutrients. 4. About 90% of the energy the mouse converts from food is stored and used by the mouse. The remaining 10% is available for consumption by predators at the next trophic level. ROLE OF A CONSUMER

HIBERNATION: 

HIBERNATION Hibernation is the way that animals adapt to the desert conditions. Animals hibernate—or deep sleep—to escape that cold.  They also do this because it is really hard to find food during the winter. We don’t think about body energy too often. Our bodies are like machines that need power to work right. Food gives animals the energy they need to walk, run, hunt for food, and lots of other things. Hibernating animals store food as body fat during the end of summer and during fall. This body fat runs their bodies all winter. This would be hard to do if they stayed awake, moved around a lot, or ran around because those things would use up the body fat before winter was over. When an animal begins to hibernate, its body temperature drops very low so that it almost matches the temperature outside. The animal’s heartbeat and breathing slow down, too. This is when that stored fat that the animal packed on in the fall comes in handy. This stored fat lasts longer because their bodies are slowed down so much that they don’t need much energy. This is how the animal makes it through the whole winter on the fat it has stored in its body. Some of these hibernators also store food in their caves and burrows. The ones that do this do not sleep straight through the winter.

DECOMPOSERS: 

One decomposer would be the dung beetle. Dung beetles are beetles which feed partly or exclusively on faeces. They do not need to eat or drink anything else because the dung provides all the necessary nutrients. The larvae feeds on the undigested plant fibre in the dung, while the adults do not eat solid food at all. Instead they use their mouthparts to squeeze and suck the juice from the manure, a liquid full of micro-organisms and other nutrients. It also includes some bacteria and fungi. These bacteria and fungi are thermophillic . These are very few in number. Dung beetle Fungi DECOMPOSERS

IMPACT OF HUMANS ON DESERT ECOSYSTEM: 

IMPACT OF HUMANS ON DESERT ECOSYSTEM These ecosystems are highly vulnerable. A heavy vehicle driven across can seriously damage the topsoil and affect the sparse vegetation. The area takes a long time to recover due to slow growth rate of vegetation and low species diversity. Increase in human population in desert, pollution from mining and storage of toxic and nuclear waste has also disturbed the desert ecosystem.

PRESENTED BY:: 

PRESENTED BY: SAHIL-16 DHAVAL-17 HARSH-18 AJINKYA-19 SWARNALAKSHMI-20 THANK YOU