1. Chapter 9 Notes “Forest”
Ecology
Chapter 9 Notes
“Forest”

2. I. Coniferous Forest

3. Location
Primarily in the subarctic regions of North America, Europe and Asia
In the Southern Hemisphere generally on high mountains, where conditions are similar to high northern latitudes
Many are harvested due to the increasing need for wood

4. Climate: Summers are warm, lasting 2 to 5 months
Winters are long, cold and dry with little sunlight
Receives 40 to 200 cm of precipitation a year

5. Organisms Coniferous means “cone-bearing”
Coniferous trees or Conifers are trees that produce seed cones
They are not diverse and contain only a few species of trees
Most common tree species: pine, hemlock, fir, spruce, & cedar
Most are Evergreens
Means they do not lose all their leaves at a given time each year
They lose and replace leaves slowly throughout the year
They share unusual leaves called Needles
long and thin covered in thick waxy substance
Help trees conserve water
Help the trees shed snow during the winters
Ferns, Lichens, and Sphagnum moss are plants that can grow in the dim light of the forest floor

6. Limiting factors = Harsh winters and nutrient poor soil
Soil is poor and acidic due to conifer needles which are acidic and decompose slowly
Snow acts as insulating blanket, trapping heat and preventing the ground from forming permafrost…which protects the roots of the trees
Small Herbivores:
Most are seed eaters
Mice, squirrels, jays, other rodents and birds
Insects are common in summer…due to the poor soil and drainage
Large Herbivores:
Moose, elk, beaver, snowshoe hare feed on plants and bark
Predators:
grizzly bears, wolves and lynx

7. II. Deciduous Forest

8. Location Grow at lower latitudes than coniferous forest
Temperate zones- areas with lower latitudes, they have four well defined seasons
Spring, summer, fall, & winter

9. Climate Temperatures vary greatly
Summer temperatures can be as high as 30 degrees Celsius (86 degrees F)
Winter temperatures can fall as low as –30 degrees Celsius (-22 degrees F)
Precipitation usually falls as rain or snow depending on the season
Receive 50 to 300 cm annually
Falls fairly regularly throughout the year

10. Organisms
Deciduous trees shed their leaves during a particular season of the year
Growing season last about 6 months
The tree grows quickly
Produces and stores large amounts of food
Autumn has shortening daylight and cooling temperatures which triggers the tree to change and shed its leaves becoming dormant
This loss of leaves allows for the tree to conserve water during cold winter months
Photosynthesis stops and tree no longer produces food
Winter is survived by consuming food stored in its trunks, branches, and roots
Spring is when the trees grow new leaves and photosynthesis begins again in preparation for the next winter
Deciduous forest are more diverse than coniferous forest

11. Six most common types of tree species :
Maple, oak, beech, ash, hickory, and birch
The forest has three distinctive layers:
Canopy: the highest layer, made up of branches and leaves of tall trees, captures most sunlight
Understory: beneath the canopy, made up of younger, smaller trees and shrubs
Forest floor: mosses, ferns and other low light plants
Soil is enriched from leaves that fall from the trees which decay quickly in the warm humid summer months forming a humus layer
Humus- home to many insects and other invertebrates that feed on abundant organic matter

12. Most common organisms in deciduous forest due to abundant food and many different habitats are:
Decomposers such as: fungi
Insects and other invertebrates
Birds, mice and other small mammals
White-tailed deer
Reptiles and amphibians (in the warmer forest)
Predators such as: wolves, mountain lions, birds of prey, foxes & migratory birds in the summer months

13. Human Impact
Deciduous forest have been changed drastically due to human activities such as farming, orchards, and urban developing
Two factors that have driven human consumption:
Rich soil…its deep and fertile due to humus making it excellent farmland
Trees…generally they are hardwoods making them better material than conifers for making furniture and flooring
Because of this impact the forest regenerates slowly because many of the species dependant on the trees have disappeared
Planted forest are known as monoculture forest
Often very productive but have low biodiversity and are highly susceptible to diseases, parasites and pollution

14. III. Rain Forest

15. Location
Located at latitudes near the equator
Tropical zone

16. Climate
Temperatures here average around 25 degrees Celsius year around (77 degrees F)
This areas receives direct rays from the sun during most of the year
Precipitation falls as rain except for atop high mountains
Receives between 200 and 400 cm of rain annually
Growing season can last 12 months
No real difference in the seasons…has almost an unchanging climate
Because of unchanging seasons, water and temperature are NOT limiting factors
Soil Nutrients is the most common limiting factor

17. General Information Most diverse terrestrial ecosystem on Earth
Biome with a dense canopy of evergreen broadleaf trees supported by at least 200 cm of rain annually
May contain as much as 70% of all terrestrial species on Earth
They only cover 6% of Earth’s land surface, but may contain 50% of Earth’s land biomass

18. Structure of Rain Forest
Trees are the basis
Thousands of extremely diverse species of trees
Most common species: cypress, balsa, teak & mahogany
Peter Ashton (British ecologist) found 700 species of trees in only 10 hectares (2.74 acres) of tropical rain forest in Borneo

19. Layers of the Rain forest:
Emergent trees- extremely tall trees which grow past the canopy
Upper Canopy- highest structure formed by the leafy tops of trees which reach as high as 25 to 30 feet
Captures almost 99% of sunlight
Lower Canopy- just below upper, made up of younger trees that have not reached their potential heights
Understory & Forest Floor- made up of plants that are able to live in low light and nutrient poor soil
Forest floor is sparse because it only receives about 1% of filtered sunlight
Soil is poor in nutrients because the dead organic matter is recycled in days or weeks instead of years like in other biomes

20. Organisms
Warm temperature and constant moisture are ideal conditions for decomposers such as: insects, fungi, and bacteria
Because of the diversity in the rain forest most organic matter is held in its organisms causing the topsoil to be thin and poor in nutrients
Most of the soil nutrients is found in the top 5 cm of soil

21. Roots are shallow to take advantage of nutrients in the thin topsoil
Because of poor, thin topsoil layer most trees widen their trunks at the bases
Buttresses: ridges of wood that support the trees at their base
Roots are shallow to take advantage of nutrients in the thin topsoil
Other plants use the trees for support
Lianas: woody vines that grow up the sides of trees to reach sunlight in the canopy
Epiphytes: plants that live entirely on the trunks or limbs of trees absorbing airborne nutrients and moisture
Bromeliads and Orchids

22. Most organisms of the rain forest live in the canopy
Arboreal: tree-dwelling organisms live their whole lives without ever touching the ground
Animals diversity is caused by two main factors:
Diversity in rain forest plants
Wide variety of habitats that exist in the different levels of the forest
Habitats vary from tree to tree and from one part of a tree to another part

23. E.O. Wilson (American biologist) found 43 species of ants on a single tree
Terry Erwin (British ecologist) estimates that there may be over 30 million species of insects on Earth, mostly in the rain forest

24. Deforestation
In 1950, over 10 percent of Earth’s land surface was covered by rain forest.
Now they only cover about 6 percent of Earth’s surface and the area is decreasing
This is due to the destruction of forest as a result of human activity
Main cause of destruction of rain forest is the human population’s need for space and wood