Reviewing Concepts

What is a system?
A system is a group of interrelated elements that work together and form a unified whole. They can be closed, open or isolated.


Types of Ecosystems
There are many different ecosystems ranging from aquatic to terrestrial. Some of them include: the Tundra, Taiga, Savanna, Tropical Rain Forest, Desert, Desert Shrub, Deep Ocean, Estuaries, Template Forests, etc. Each of these types is different in temperature, rain fall, fauna, flora, latitude, altitude, and many other elements. 


Trophic Levels
Trophic levels are the position of an organism in a food change. Starting with producers, which make up the first level, to herbivores, second level also called primary consumers, to carnivores which make up the rest of the levels, usually secondary or tertiary consumers depending on the level. Not every food chain has the same number of levels, it depends on the amount of organisms which participate in it. 


Example:
1st level: Grass (producer) ---> 2nd level: Snowshoe Hare (primary consumer)---> 3rd level: Lynx (secondary consumer)


THE TAIGA!
The taiga is an ecosystem located in northern latitudes beneath the tundra. It is usually found in Canada, Russia, Sweden, Finland, Norway and the extreme northern parts of the United States. In this ecosystem temperatures range from -54°C to 30°C throughout the year. Snow and ice usually appear in winter, which occurs most of the year since summer is really short. During summer the air is humid which allows vegetation to grow, but in general there is a very small amount of precipitation and winters are very dry. Vegetation in the lower parts include a large amount of trees and mos but in higher parts trees are sparse and lichens are more common. Animals include the snowshoe hare, lynx, wolfs, bears, moose, deer, owls, eagles, raccoons, etc. 
The trees and small lichens that live in the taiga are the producers of most of the energy that is used in the taiga. There are lots of different omnivores and herbivores which eat these plants and store the energy so carnivores can take it. The matter flow is generally moderated by decomposer organisms like fungi and bacteria. Decaying bodies from plants and animals are broken down by them so that matter is recycled. During winter both energy and matter flow decreases because of the migration of many of the species to other warmer places.