Agriculture Technology
Ecology and Wildlife Unit
Chapter 1 Notes
The fish and wildlife populations of North America are among our most treasured natural resources… and one of the most vulnerable.
They are treasured not only because of the deep appreciation many people have for wild creatures, but also for the part they play in our ecosystem. They are vulnerable because certain activities can upset delicate relationships between wild animals and their living environments.
Ecology:
The branch of biology that describes relationships between organisms and the environments in which they live.
Conservation of matter:
A basic law of physics that essentially states that matter can be changed from one form to another, but it cannot be created or destroyed by ordinary physical or chemical processes.
Industrial wastes:
Have been a serious problem for years. Typically happens when industrial manufacturing plants do not dispose of harmful substances in a safe manner. Many dispose of by use of water. Contaminates our surface waters.
Pollutants are dangerous waste materials that cause negative effects on the environment – water and air are our two major concerns.
Some pollutants that affect surface water eventually will contaminate the groundwater. Most groundwater is located in aquifers.
If disposed of correctly, most solid wastes (garbage) pose very little damage. It is the toxic liquids that can present negative effects.
Agricultural concerns arise out of the use of pesticides. A pesticide is a chemical used to combat pests. Most have come into existence since the end of WWII. Most common are: insecticides, herbicides, fungicides, and rodenticides.
If not used correctly and disposed of in an appropriate manner, serious environmental damage can occur. Many of the empty containers are labeled as hazardous materials.
Petroleum products are especially harmful. These are typically an oily, flammable liquid that occurs naturally in large underground deposits.
Laws of Energy.
Energy is the ability to do work or to cause changes to happen. Energy cannot be recycled, but it can be stored. There are two basic environmental laws of nature:
- Energy cannot be created or destroyed, but it can be converted from one form to another. (radiant, chemical, kinetic, thermal, and electrical).
- Each time energy is converted from one form to another, some energy is lost in the form of heat.
Natural Cycles
The elemental cycle is a circular flow of elements from living organisms to nonliving matter. Typically involves Carbon, nitrogen, and water (hydrogen and oxygen).
Carbon is most abundant element in living organisms.
Fossil fuels.
Nitrogen: fixation is when nitrogen gas is converted to nitrates. Done by either nitrogen fixing bacteria, or by denitrification.
Water Cycle involves water moving from oceans and eventually back to the oceans. Transpiration is loss of water from leaves of plants through their stomates. Occurs only during light (process of photosynthesis).
Food Chains:
Are made up of a sequence of living organisms that eat and are eaten by other organisms that live in the community. Most are very complicated.
General organization:
Top – producers
Second – primary consumers (herbivores)
Third – secondary consumers (carnivores)
A food pyramid arranges organisms in a ranking order according to their dominance in a food web.
Ecology and wildlife notes chapter 1page #1