PACKET #21CHAPTER #6

Introduction to Ecology

Introduction

Ecology The scientific study of the interactions between

organisms and the environment Ecologists, under the umbrella of ecology, pose

questions and devise hypotheses about ecosystems. Where does a species of organisms live? Why do they live there? How many of those organisms are there?

Ecosystem

Complete community of living organisms and the nonliving materials of their surroundings

Consists of Biotic components

Living organisms Abiotic components

Non-living factors Light Temperature Water

Levels of Ecological Study

Organismal Ecology Study of individual organisms’ behavior, physiology, etc.

Population Ecology Study of populations in relation to the environment

Environmental influences Population density and distribution Age of members

How do populations grow? Is there a limit to the number of organisms within a population?

Community Ecology Study of interactions between organisms, of various populations,

at a particular site or in a specific areaEcosystem Ecology

Study of movement of energy and matter through ecosystems

Man, His Environment & Impact on Ecosystems

Question

How would you describe the major human influences on the environment?

Primitive man Affected environment

Hunting Fishing Removing trees for fires and shelters

There was a demand for land to cultivate and harvest crops and to grow communities

Cultivation of crops done with domestic animals and they had to be fed as well Leaving less for human consumption

More modern man Discovery of fossil fuels Machines were now used to help grow more crops Population became larger Fertilizers, pesticides and “rapid” transportation developed

Brought the problem of pollution Nuclear energy was developed with its consequent environmental problems

Exploitation of Natural Resources

Agriculture Fire used to clear large areas of land for planting Vegetation destroyed and replaced by mono-culture

Field of cereal crops replaced a forest of oak Placed a demand on soil nutrients after growing same crop

for a number of years How could this problem be avoided?

• Rotating crops Excess use of fertilizers

Caused pollutants to run off into rivers due to leaching and draining

Weeds and pests also compete for resources and with only one main species as competition, soil nutrient problems also arise

Renewable Resources

Renewable resources are basically things that grow and are therefore replaced. Does not mean that the resources are inexhaustible If the resource is utilized too much, at too much of a

great rate, they will most certainly diminish and even disappear altogether

Reason why there are harvesting seasons Lobster Crab Salmon

What is your opinion on how man has utilized these renewable resources?

Non-renewable Resources

Not replaceable Oil Gas Coal Mineral ores

Will oil and gasoline run out? Some believe so!

Human Population Explosion

Questions posed by scientists? Will the human population reach it’s carrying capacity?

The explosion in human population has resulted in: - An increase in the use of non-renewable resources An increase in land, air and sea pollution as a result of

fuel combustion by-productsToday, finding a cost effective measure, where

resources are not totally used up, is not easy and there are many arguments between conservationists and industry

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