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Introduction to Ecology

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Ecology defined

Gk. oikoshousehold; logosstudy

Study of relationships between living organismsand their environment; interaction of organisms

with one another Environment all factors (living and non-living)

that actually affect an individual organism orpopulation at any point in the life cycle

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Human-Environment Interaction

All organisms on earth including humans areinfluenced by the environment.

Organisms in turn modify the environment.

Human well-being is entirely dependent on nature. Primary industries utilize natural resources directly

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Organism

Population

Community

Ecosystem

Biome

Biosphere

Ecological Levels of Organization

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Areas of Interest in Ecology

Behavioral Ecology

Population Ecology

Community Ecology Ecosystem Ecology

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Behavioral Ecology Focuses on the ecology of individual organisms

Concerns how behavior contributes to the survivorship,reproduction, and population growth of species

Population Ecology Focuses on how physical factors affect populations growth

and population size Competition, predation, and herbivory

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Community Ecology Focuses on biodiversity and what influences the number of

species in an area

Conservation biology

Ecosystem Ecology

Concerned with the passage of energy and nutrients

through communities and what effects energy andnutrients have on those communities

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Basic Ecological Concepts and Principles

Components of an Ecosystem

Basic Laws in the Ecosystem

Energy Flow in the Ecosystem

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What is an ecosystem?

System

- a set of components or parts that function together to actas a whole

- parts are interconnected, interdependent, and interrelatedto make up a whole

- each component can be isolated and studied separately

Ecosystem

- ecological system- term was proposed by Arthur G. Tansley (1935)

- any unit that includes all the organisms in a given areainteracting with the physical environment

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Ecosystem Services

The human economy depends upon the services performedfor free by ecosystems.

The ecosystem services supplied annually are worth manytrillions of dollars.

Economic development that destroys habitats and impairsservices can create costs to humanity over the long termthat may greatly exceed the short-term economic benefitsof the development.

These costs are generally hidden from traditional economicaccounting, but are nonetheless real and are usually borneby society at large.

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Partial list of the worlds ecosystem services

SERVICE EXAMPLE

INDIRECT

Atmospheric gas regulation Maintenance of carbon dioxide, ozone, and sulfur dioxide levelsClimate regulation Maintenance of carbon dioxide, nitrogen dioxide, methane, and CFC levels

Disturbance regulation Storm protection, flood control

Waste treatment Sewage purification

Soil erosion control Retention topsoil, reduction in siltation of lakes

Nutrient recycling Maintenance of nitrogen, phosphorus, carbon and other elemental cycles

DIRECT

Water supply Irrigation, provision of water for industry

Pollination Pollination of crops

Biological control Regulation of pest control

Refuges Maintenance of habitats for wildlife

Food production Production of crops, maintenance of livestock

Raw materials Provision of renewable fuels and timber

Genetic resourcesMaintenance of plants and animals for medicines and provision of genes forplant resistance

Recreation Ecotourism

Cultural Aesthetic value

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Components of an Ecosystem

Biotic components

can be classified according to their mode ofenergy acquisition

autotrophs and heterotrophs

Abiotic components

form the environment and determine the type/structure of ecosystem

provides practically all the energy for an

ecosystem

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Components of an Ecosystem

Biotic components

Autotrophs: self-nourishing; called primaryproducers

Photoautotrophs: fix energy from the sun and storeit in complex organic compounds

green plants, algae, some bacteria

Chemoautotrophs (chemosynthesizers): are bacteria

that oxidize reduced inorganic substances (typicallysulfur and ammonia compounds) and producecomplex organic compounds

nitrifying bacteria and those that live in hydrothermal vents

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Components of an Ecosystem

Biotic components Heterotrophs: other-nourishing; cannot produce their

own food directly from sunlight + inorganic compounds;

require energy previously stored in complex molecules Phagotrophs: to eat; ingest other organisms or particulate

organic matter

herbivore, carnivores, omnivores

Saprotrophs: decomposers; obtain energy either by breaking

down dead tissues or by absorbing dissolved organic matter;nutrient cycling

bacteria and fungi

Saprophages / detritivores: feed on dead organic matter

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Components of an Ecosystem

Abiotic components

Solar energy, air, water, substrate

Inorganic substances (e.g., sulfur, boron, tend to cycle

through ecosystems) Organic compounds (such as proteins, carbohydrates,

lipids, and other complex molecules) form a linkbetween biotic and abiotic components of the system.

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Ecosystem Model

INPUT ENVIRONMENT

Sun

Otherenergy

Input of materials;immigration oforganisms

=

SYSTEM

=

OUTPUT ENVIRONMENT

Processed energy andmaterials; emigration oforganisms

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Basic Laws in the Ecosystem

Law of the Minimum Justus von Liebig (1840); LiebigsLaw

states that the growth of a plant will be limited by whichever requisite factor is themost deficient in the local environment; only by increasing the amount of the limitingnutrient (the one most scarce in relation to "need") was the growth of a plant or

crop can improve

Law of Tolerance Victor Ernest Shelford (1913)

states that the distribution of a species will be limited by its range of tolerance for

local environmental factors

Law of the Limiting Factors states that too much or too little of any abiotic factor can limit or prevent growth of

a population of a species in an ecosystem

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Energy Flow in an Ecosystem

Energy- ability to do work

- heat, light, chemical, electrical

- Law of Thermodynamics

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Law of Thermodynamics

1. Law of Conservation of Energy

- energy must be transformed from one form into another but isneither created nor destroyed

2. Law of Entropy- measure of the unavailable energy resulting from transformations

- transformations of energy always result in some loss or dissipation of energy

- index of disorder- organisms, ecosystems, and the entire biosphere can create a high state of

internal order or a condition of low entropy if there is a continuous dissipationof energy of high utility into energy of low utility

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A= autotrophs; H= heterotrophs; S= storage HEAT

Sourceof materials(nutrients)

Sourceof organic

matter

SUN A

H

SNutrients

SOrganics

H

H

H

EXPORT

Immigration andemigration oforganisms

Nutrientcycling

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Climatic factors

Climatic factors are abiotic factors like temperature,humidity, atmospheric pressure, movement of air andwater, precipitation and evaporation of water

Climate is a general pattern of weather for a particular areafor over a period of time

dictated by the amount of solar energy reaching the Earthssurface

uneven heating of Earth produces various types of climates

(conditions) controls the species distribution and composition of an ecosystem

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Activity 1: Climatic factors in the ecosystem

Objectives:

1. Identify the various climatological factors and observepossible relationship that exists among factors.

2. Measure climatic elements using simple field instruments.

3. Compare climatic elements from various environmentalconditions.

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Activity 1: Climatic factors in the ecosystem

Described and present a clear illustration of the locationassigned to your group.

Assign five (5) random points within the assigned area andmeasure the following parameters:

Temperature

Relative humidity

Air pressure

Precipitation

Rate of evaporation

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Area designation

Group Open Area Inside Shaded area

1 and 2 Oval Main building -

3 and 4 Freedom Plaza Charlie delRosario

-

5 and 6 Lagoon NALLRC -

7 and 8 Open Court PE Building -

9 and 10 Linear Park Gym -