Lesson 1: Wave Motionwalp.weebly.com/uploads/1/2/0/0/1200808/module_1_-_e… · Web viewFigure 1.2 shows an example of the direction of groundwater flow. Figure 1.2 Divisions of

UNIVERSITY OF TRINIDAD AND TOBAGONETD PROGRAMME

Module 1 – Environmental introduction

Objectives

This module will define key terms related to environmental science; describe the water cycle with

particular reference to the processes involved in the cycle; explain the interdependency of the

`ecosystem`; describe environmentally sensitive area rules 2000; and describe environmentally

sensitive species rules 2000.

The environment is all around us. It is our surroundings. It is the air we breathe. The water we drink and the source of our food. According to the dictionary it is all the conditions that affect the development of an organism.

The environment consists of both natural and man- made elements. The natural environment is designed to be independent and contains delicate interrelationships between living and non – living things.

The natural environment moves in continuous cycles and nature completely converts its wastes and resources to be reused. These cycles are closely interknit and can easily be disrupted if the proper planning and considerations are not given to the outcome.

____________________________________________________________________SAFE 111D – Environmental SafetyModule 1 – Environmental Introduction 1


The Water Cycle

Water is one of our most important natural resources. At least half the body weight of all living plants and animals is composed of water and about 70 % of your body weight is water.

Figure 1.1 Hydrological Cycle(courtesy of U.S. Department of the Interior/U.S. Geological Survey)

There are a number of processes involved in the hydrologic cycle including evaporation, transpiration, condensation, precipitation and infiltration/percolation although figure 1.1 clearly shows other processes and even then it is a highly simplified version of what actually happens.



Evaporation describes the conversion of water found in rivers, lakes, seas and oceans into water vapour normally through heat provided by the sun. Transpiration also describes the conversion of water to water vapour but in this case it refers to moisture drawn from the soil by roots of plants and evaporated into the atmosphere from surface of their leaves. It is common to talk about these two processes under the joint description of evapotranspiration.

Condensation occurs in the atmosphere where the water vapour is converted back into the liquid state and precipitation occurs when that water falls to earth in the form of rain, sleet or snow. The water will then find its way back to the seas, oceans and other bodies of water by means of streams, rivers and groundwater. Groundwater describes water that infiltrates the soil and provides moisture for plants, etc. Groundwater also recharges aquifers.

The hydrologic cycle is now almost complete but there are further stages including infiltration and percolation, both processes contributing to groundwater as described in the previous paragraph. Infiltration describes the movement of water into the soil and percolation describes how it moves through soil and rock in a downward direction. Figure 1.2 shows an example of the direction of groundwater flow.



Figure 1.2 Divisions of Subsurface Water

The hydrologic cycle is almost a closed system, there is very little gain or loss of the total amount of water in the world although much of that water many not be immediately available, for example, locked in the ice caps in the Arctic and Antarctic.

ECOLOGY

Many areas of study contribute to our understanding of the environment. Ecology, the study of plants and animals in relation to their environment, brings these many areas together. Ecosystems, plants and animals living in balance with their environment, can be complex but most are balanced.



Figure 1.3 Diagram of a simple ecosystem.

Organisms can be either producers or consumers in terms of energy flow through an ecosystem. Producers convert energy from the environment into carbon bonds, such as those found in the sugar glucose. Plants are the most obvious examples of producers; plants take energy from sunlight and use it to convert carbon dioxide into glucose (or other sugars). Algae and cyanobacteria are also photosynthetic producers, like plants. Other producers include bacteria living around deep-sea vents. These bacteria take energy from chemicals coming from the Earth's interior and use it to make sugars. Other bacteria living deep underground can also produce sugars from such inorganic sources. Another word for producers is autotrophs.

Consumers get their energy from the carbon bonds made by the producers. Another word for a consumer is a heterotroph.

A trophic level refers to the organisms position in the food chain. Autotrophs are at the base. Organisms that eat autotrophs are called



herbivores or primary consumers. An organism that eats herbivores is a carnivore and a secondary consumer. A carnivore which eats a carnivore which eats a herbivore is a tertiary consumer, and so on. It is important to note that many animals do not specialize in their diets. Omnivores (such as humans) eat both animals and plants.

Further, except for some specialists, most carnivores don't limit their diet to organisms of only one trophic level. Frogs, for instance, don't discriminate between herbivorous and carnivorous bugs in their diet. If it's the right size, and moving at the right distance, chances are the frog will eat it. It's not as if the frog has brain cells to waste wondering if it's going to mess up the food chain by being a secondary consumer one minute and a quaternary consumer the next.

Energy Flow through the Ecosystem



Figure 1.4 Energy flow through an ecosystem

In the flow of energy and inorganic nutrients through the ecosystem, a few generalizations can be made:

1. The ultimate source of energy (for most ecosystems) is the sun 2. The ultimate fate of energy in ecosystems is for it to be lost as heat. 3. Energy and nutrients are passed from organism to organism through

the food chain as one organism eats another. 4. Decomposers remove the last energy from the remains of organisms. 5. Inorganic nutrients are cycled, energy is not.



FOOD WEBS

Food webs are the pattern of feeding relationships in an ecosystem.

Figure 1.5 Food Web

The food energy stored by plants is passed through the ecosystem in a series of steps. In Fig. 1.5 for example, bananas are consumed by monkeys, monkeys become food for jaguars.

BANANAS MONKEYS JAGUARS



This is also an example of a food chain, FOOD CHAINS FOLLOW A SINGLE PATH AS ANIMALS EAT EACH OTHER.

In Summary:

All of the components of an ecosystem are connected and it is impossible to alter one without affecting another. When man ignores these connections, an ecosystem can become unbalanced and permanent changes in the environment can happen. For example, introducing rabbits into Australia, where no natural predators for rabbits existed, caused devastation to vegetation on the continent.

Sometimes the effects don’t occur immediately and often it is hard to know what they may be, but a more comprehensive approach to development and conservation is emerging. Too often air and water resources are presumed to belong to everyone but no one takes responsibility for their conservation. Therefore they are undervalued and assumed to be available for the benefit of any who take advantage of them with a “what can`t be seen, can`t hurt” attitude. All ecosystems are essential and wise decision making and long term planning are necessary for them to be maintained.

QUESTIONS

1) Describe the “water cycle”.

2) Define ecology.

3) What is meant by the terms “consumers and producers”?


Documents

Lesson 1: Wave Motionwalp.weebly.com/uploads/1/2/0/0/1200808/module_1_-_e… · Web viewFigure 1.2 shows an example of the direction of groundwater flow. Figure 1.2 Divisions of