Species Approach

When there are no more animals of a particular species left alive, that species is said to be extinct.

In the distant past, several species of animals became extinct through natural causes. There might have been a change in the climate of a particular region, and the plants or animals on which the species lived could have died out because of the change in the weather. Or one animal might have been destroyed by another that was stronger or faster.

But ever since human beings have been on Earth, and especially in the last hundred years, animal species have become extinct because of hunting, pollution, or the destruction of the places where they live.

So many animals are now in danger of extinction that a list is kept in a Red Book. unfortunately, the list gets longer every year.

Characteristics of animals prone to extinction

Endemic species

• Low reproductive rate
• Specialized niche
• Feeds at high trophic level
• Fixed migratory level
• Commercially valuable

Invasive species vs. Ecosystem

Invading species success because:

• High reproductive rate
• Wide life span
• High dispersion rate

The new ecosystem is adequate because there are not direct depredators, the climate conditions are the correct ones.

Disadvantages:

• You just focus your efforts in just one species
• Not holistic
• ‘Cause not all the variable are considered you could miss a higher priority
• Connections between species, biotic and abiotic factor cannot be ignored

Wastes, Disposal and Strategies for Control

Type of Waste	Disposal	Strategy for control
Heavy Metals	Landfills. If not properly confined the leachate may pollute soil/ground water.	Mixed with cement and additive that encloses the sludge.
Nuclear Wastes	Depends on the type of waste: -For low levels, material is compressed and buried in landfills -For inter, level it may be solidified in concrete and buried -For high level, it is placed in a container Reuse (weapons, not cost-effective; hybrid reactors)	Very difficult. Confinement is needed wastes take thousands of years to decay. An option is to deplete highly radioactive materials
Organic Wastes	Pumping wastes into deep wells. The mulch is used as fertilizer. Land —> provides biogas.	Biotech processes open / closed composting use microorganisms or worms. Aerobic / anaerobic bacteria break down organic matter. Incinerators /pyrolysis
Plastic Wastes	Landfills Incinerators. Reuse/recycling	Efficient incineration provides useful thermal energy and control of the gases released. Treatment Conversion into fuels (Polymer Energy System)
Oils and Solvents	Small amount placed in containers and put in trash, landfills Larger amounts, containers for recycling; oil –> biofuels. Incinerators	Bioprocesses –> microorganisms break down molecules into simpler compounds.

 

 

Method	Description
Landfills	Confinement of wastes into an area, covered by soil
Incineration	Wastes are burned
Recycling	Materials are changed and used in other products
Reuse	A new use is find for materials or they are reused for the same purpose.

 

 

Indicator Species

Aquatic ecosystems
Oyster: They fed on organic material and pollutants in the water. They filter the water, removing the particles.
Vertebrate and invertebrate species: Found in rivers and streams. Can determine the grange pollution to kept in check.
Lilies: rivers, lakes, ponds and swamps. They absorb oxygen and sunlight. Indicate abundance of nutrients, which leads to eutrophication.

Mayfly larvae: Native specie that are adapted to live in certain biome. When its number decreases it is a very clear sign that the pollution levels are increasing. They reappear downstream as the effects of the discharge are diluted. This help to indicate the level of pollution in water.
Sludge Worm. Common in lakes and rivers. All fresh water ecosystems. They fed on the sediments and bacteria, hence a great population on them might indicate great pollution in the body water and oxygen-poor water. They indicate stagnant water unfit to drink.
Soil Indicator species
The plants that are found in certain soil might indicate the presence or absence of a specific substance.
Besides plants, there are many other indicators.
Birds eggs can be analyze to find out pesticide sin the soil.
Invertebrates:. Indicator species to identify the use of foreign soils, insecticides, pesticides, and other pollutants.
In Canada there are plans to use soil-living arthropods in order to quantify the pollution in the forests.
A good way to measure the healthiness of an ecosystem and to determine the presence of pollution is biodiversity. High biodiversity indicates a strong and healthy environment.

  .

Matter keeps rolling...

Inside the ECOSYSTEMS we find some cool features. Now we'll work with each of the elements that form them.

Living organisms are presented in every ecosystem. They have seven main characteristics:

1. They have/are cells

2. They reproduce

3. Grow and develop (die)

4. Absorb and use energy and materials

5. Maintain homeostasis

6. Respond stimuli

7. They're organized

There are thousands and thousands of organisms around the world. They're classified with different schemes or keys.

Organisms within an ecosystem can be recognized as producers, consumers, and decomposers by the way they obtain matter and energy. This division brings on the trophic levels.

Energy and matter flows through these trophic levels. As it had been told, energy is not completely transfered between levels 'cause some of it is used by each organisms.

Each organism found within an ecosystem is called an individual. Individuals that share similar characteristics and can reproduce between them form can be identify as a specie. A group of organisms of the same specie form and population. When populations are found together in a given area and interact between them they form a community.

Rollin' to the "ecosystems"

Now, let's talk about the ecosystem. We already know what's a system so let's analyze the word.

ECOSYSTEM

First think that comes to mind, at least for me, is nature, animals, trees, bushes, sunny skies, dry lands or rainy days. Actually with this simple idea the definition of ecosystem can be got.

An ecosystem is the relation between biotic (living components) and abiotic (non-living components) factors in an environment.

Some examples of ecosystems

- A grassland

- A forest

- A pond

- The PrepaTec Cumbres and its surroundings.

In ecosystems matter and energy goes in and out, constantly.

Energy "goes through the system" while matter "circulates around" it.