Ecosystem

Why are there so many living organisms on Earth, and somany different species? How do the characteristics of thenonliving environment, such as soil quality and water

salinity,help determine which organisms thrive in particular areas?These questions are central to the study of ecosystems—communities of living organisms in particular places and thechemical and physical factors that influence them. Learnhow scientists study ecosystems to predict how they maychange over time and respond to human impacts.

Introduction

Ecology is the scientific study of relationships in the natural world. It includes relationships between

organisms and their physical environments (physiological ecology); between organisms of the same species (population ecology); between organisms of different species (community ecology); and between organisms and the fluxes of matter and energy through biological systems (ecosystem ecology).

Ecosystem

1All Ecosystem exist and real like a pond, forest, ocean or even an aquarium.

2. Ther is a regular circulation of nutrients in ecosystem between the living and non living.

3. Important feature of Ecosystem is the adaptation to local environmental conditions.

4. The series of cycle involved water cycle, oxygen cycle, nitrogen cycle.

Characterstic of Ecosystem

There are essentially two kinds of ecosystems; Aquatic and Terrestrial.

Any other sub-ecosystem falls under one of these two headings.

1. Natural Ecosystem.2. Man made Ecosystem.

Kinds of ecosystem

It is an ecosytem developed under natural conditions without any appreciable human interference . Natural ecosystem an be terrestial ecostem, (forest ecosystem, lake ecosytem, pond ecosystem) or aquatic ecosystem ( fresh water ecosytm, ocean ecosytem etc.)

Natural Ecosytem

These are the artificial ecosystems which rely on the human efforts to sustain. They do not possess a self regulating mechanism. They have almost no diversity and have simple food webs. The cycling of nutrients is negligible. The inputs are provided by the human efforts. The man made ecosystems include the villages, towns, cities, rivers, orchids, dams, gardens, lakes and agriculture. The agriculture consists of the animal husbandry and the production of crops. The agriculture is the first manmade ecosystem which occurred with the increase in human population.

Man made Ecosystem

Natural Ecosystem

Man made Ecosystem

Producers, Consumers, and Decomposers

The Connections Among Life

Producer: Organism which produces its own food by using energy from the sun

www.chappyspowerorganics.com/ mycinnoc.html www.edhelper.com/plants.htm

www.tadininc.com/ tadin%20map1.htm

www.afaith.com/photos/ tree.jpg

ckso.uhome.net/gallery/ grass.jpg

www.snfisher.com/Plants/ thumbs_d/thumbs_p.html

Consumer: Organism which doesn’t make its own food, but gets it from eating plants or other animals

www.mnzoo.com/animals/ index.asp

www.busy-bees.com.au/

JIGSAWPUZZLES3years+.html

www.dandin.com/group.html

www.healthwell.com/.../D_Backs/

Sep_00/happymeal.cfm?path=hw

www.nhm.ac.uk/science/consulting/ cmdetail.html

www.saltlake-audubon.org/ birding/story.htm

Decomposer: Organism which digests or breaks down formerly living material

www.tiehh.ttu.edu/mhooper/ research.htm

www.nhptv.org/natureworks/

graphics/mush11.jpg

uc.rutgers.edu/medrel/photos/ bacteria-green.jpg

www.nhptv.org/natureworks/ graphics/earth11.jpg

Herbivores are animals that eat ONLY plants.

They need a lot of energy to stay alive.

Many have to eat all day long to get enough energy.

Some herbivores have a special digestive system so they are able to eat grasses.

Herbivores

Manatee

A manatee is a mammal that lives in the water.

They are herbivores.

They eat 150 pounds of plants each day!

Manatees live in ocean waters off the coast of Florida.

A carnivore is an animal that gets its food from eating other animals.

They are also called a “meat eater

Carnivores

Lions eat other animals such as gazelles, antelopes, and zebras.

Omnivores are animals that eat both plants and other animals.

Many will eat the eggs of other animals.

Some omnivores are scavengers which means they eat dead animals.

Most will eat plants that produce fruit and vegetables. They also eat the fruit and vegetables.

Omnivores

A pig eats fruit, eggs, corn, and earthworms.

An ecological pyramid (also trophic pyramid or energy pyramid) is a graphical representation designed to show the biomass or biomass productivity at each trophic level in a given ecosystem.

Biomass is the amount of living or organic matter present in an organism. Biomass pyramids show how much biomass is present in the organisms at each trophic level, while productivity pyramids show the production or turnover in biomass.

Ecological pyramid

Ecological pyramid

Ecological pyramids begin with producers on the bottom (such as plants) and proceed through the various trophic levels (such as herbivores that eat plants, then carnivores that eat herbivores, then carnivores that eat those carnivores, and so on).

Ecological Pyramid

Ecological Pyramids Three types of ecological pyramids

Pyramid of Energy

Pyramid of Biomass

Pyramid of Numbers

Ecological Pyramids Pyramid of Energy

Indicates the total amount of energy present in each trophic level

Shows the loss of energy from one trophic level to the next

Shows that the energy transfer from one trophic level to the next is accompanied by a decrease due to the conversion of potential energy into kinetic energy and heat energy

Only 10% of the overall movement of potential energy is transferred to the next tropic level

Ecological Pyramids

energy transferred

energylost

Ecological Pyramids Pyramid of Biomass

Indicates the total dry mass of the organisms in each trophic level

The size of the organism is over-emphasized and it can happen that the mass of level 2 is greater than that of level 1, because the productivity of level 1 is not taken into consideration

Thus an enormous mass of grass is required to support a smaller mass of gazelle, which in turn would support a smaller mass of lions.

Ecological Pyramids

tertiaryconsumers

secondaryconsumers

primaryconsumers

producers

75 g/m2

150g/m2

675g/m2

2000g/m2

Ecological Pyramids Pyramid of Numbers

Shows the number of organisms in each trophic level and does not take into consideration the size of the organisms and over-emphasizes the importance of small organisms

In a pyramid of numbers the higher up one moves, so each consecutive layer or level contains fewer organisms than the level below it

Ecological Pyramids

tertiaryconsumers

secondaryconsumers

primaryconsumers

producers

5

5000

500,000

5,000,000

Energy flow Simplistically:

This pattern of energy flow among different organisms is the TROPHIC STRUCTURE of an ecosystem.

heat

Producers Consumers

Decomposers

heat

The Laws of Thermodynamics

Energy flow is a one-directional process.

sun---> heat (longer wavelengths)

FIRST LAW of THERMODYNAMICS:

Energy can be converted from one form to another, but cannot be created or destroyed.

Transformations of energy always result in some loss or dissipation of energy

or In energy exchanges in a closed system, the potential

energy of the final state will be less than that of the initial state

or Entropy tends to increase (entropy = amount of

unavailable energy in a system or Systems will tend to go from ordered states to disordered

states (to maintain order, energy must be added to the system, to compensate for the loss of energy

SECOND LAW of THERMODYNAMICS

Natural, gradual changes in the types of species that live in an area; can be primary or secondary

The gradual replacement of one plant community by another through natural processes over time

Changes in Ecosystems:Ecological Succession

Begins in a place without any soil ◦ Sides of volcanoes◦ Landslides◦ Flooding

Starts with the arrival of living things such as lichens that do not need soil to survive

Called PIONEER SPECIES

Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces

When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil

Primary Succession

Primary succession-

New bare rock comes from source: ◦ volcanic lava flow cools and forms rock

Begins in a place that already has soil and was once the home of living organisms

Occurs faster and has different pioneer species than primary succession

Example: after forest fires

Secondary Succession

Secondary Succession

Pond Succession

Food Chains

and Webs

Producers

Primary Consumers

Secondary Consumers

Tertiary Consumers

The Producers

Producers are the beginning of a simple food chain. Producers are plants and vegetables.

The Producers All energy comes

from the Sun and plants are the ones who make food with that energy. They use the process of photosynthesis in Plants also make loads of other nutrients for other organisms to eat.

•Tertiary consumers (3rd order) –Eat the primary and secondary consumers (CARNIVORES) ex: wolf eats cat and squirrel

•Secondary consumers (2nd Order)–Eat the primary consumers (CARNIVORES) example: cat eats squirrel

•Primary consumers (1st Order)–Worms, insects, squirrels, mice: all eat plants (HERBIVORES) ex: squirrel eats acorns

The last links in the chain are the decomposers. (They break things down) Like bacteria, mold, fungi, mushrooms

•If you die, they eat you. •If you lose a leaf, they eat it.

Whenever something that was alive dies, the decomposers get it.

The Decomposers