Island Biogeography• First proposed by E.O. Wilson & Robert MacArthur in the 1960s. • Now is a fundamental concept in conservation techniques.• “Island” is any area of suitable habitat surrounded by an area of

unsuitable habitat•Must consider these when designing protected areas:

1. Size2. Shape3. Proximity to humans & other disturbances4. Corridors5. Amount of edge

One More…Which is better (black or white? Why?

SLOSS

Notes from Raven & Berg

Chapter 17

Forest Ecosystem Services• What do you think?

• Supply materials for humans• Fuel, timber, paper products

• Medicines, Foods• Moderation of local climate (transpiration)• Biogeochemical Cycles• Erosion control• Watersheds• Animal habitat

Managed Forests•Most are monocultures•Planted in rows• Same size, same age trees•Prone to insects/diseases• Insecticides, fungicide use is common• Simpler ecosystem due to the monoculture in trophic level 1

Harvesting Trees• 5 countries have the most trees…• US, Canada, Russia, China, Brazil

• 55% of the trees are burned • (fuel wood or charcoal)

• 45% used for paper / wood products• In highly developed nations!!

Methods of Harvesting Trees• Selective Cutting• Shelterwood Cutting

• Seed Tree Cutting• Clearcutting

Harvesting Methods - Selective Cutting• Cut a few mature trees individually or in small clusters. Rest of the

forest is intact.

Harvesting Methods - Shelterwood Cutting• Some mature trees are harvested. Remaining trees provide

protection/shade for younger trees to regenerate. Logging continues as those grow up.

Harvesting Methods - Seed Tree Cutting• Nearly all trees are harvested, leaving a few desirable trees to provide

seeds for regeneration.

Harvesting Methods - Clearcutting• Removal of all trees. Area is reseeded or replanted.

Discussion: Compare/Contrast the 4 methods

• Which is most desirable for Loggers? For natural species?

• Would all species be impacted the same by a certain method? Why/Why not?

• What are the PROS & CONS of each? (environmentally and economically)

• Would TREE AGE & TREE TYPE impact which method you choose?

• Would the product being created impact which method you choose?

Deforestation• World decrease of 37 million acres yearly• Causes:• Drought, land clearing, expansion of agriculture, road construction, tree harvesting,

insects, disease

• How does this impact soil?• How does this impact waterways?• How does this impact groundwater?• How does this impact species?• How does this impact climate? (temperature, moisture)

US Forest Conservation – Forest Legacy Program• For privately owned lands• Landowner & government agency/conservation organization

enter into a “conservation easement” agreement• Landowner sells land to the government or a conservation

organization with understanding that it will be protected from development for a certain number of years.• Type of easement (permanent or for X number of years) varies• Land remains in private ownership.

Wetlands & Coastlines – Ecosystem Services

Name some from the cartoon.

• Groundwater recharge

• Reduce flooding

• Improve water quality (filtration)

• Habitat

• Products (food, etc)

• Recreation

Wetlands & Coastline Threats• Threats• Drainage for pest control• Dredging for navigation• Dam construction• Dykes for flood control• Use for waste dumping• Development (buildings)• Aquaculture use

• Protection• Wetland Reserve Program• All about education!• All about ownership!

• Marine Sanctuaries are commonly:• Coral reefs• Kelp beds• Shipwrecks …..Why?????• Managed for multiple uses

Interesting agricultural methods

Shelterbelts – minimize wind erosion

Vegetation can minimize odor movement