1. Land Management And Minerals
Unit 5: The Geosphere

2. Different Categories
As our population grows, more resources from rural lands are needed to support the population
Land can be broken down into…
Farmland
Rangeland
Forest land
Parks and Preserves
The Wilderness
Regardless of how we managed the land (good or bad), it is essential for those ecosystem services.

3. Farmland Used to grow crops and fruit
The U.S. once contained more than 100 million hectares
Threatened by urban development
1996 – Farmland Protection Program
Think back to agricultural ethics!

4. Rangeland Supports different types of vegetation; not used for farming
Commonly used to feed livestock
Most damage comes from overgrazing (too many animals)—changes the plant community (invasives!)
1978 – Public Rangelands Improvement Act was enacted to improve land management practices
Leaving it alone
Reducing herd size
Planting native species; killing invasive ones
Spreading out water holes
But also native species! (benefit off of this)
Both this and farmland are essential for maintaining the world’s food supply

6. Forest Land
We use timber products everyday: wood and paper; but also maple syrup and turpentine (making paints)!
Three categories: virgin (never been cut), native (but managed), and tree farms (planted in rows; cut down)
Harvesting trees
Clear-cutting – removing all trees from an area (bad for wildlife and causes soil erosion)
Selective cutting – cutting and removing middle-aged trees
To get what we need: equivalent to each person cutting down a tree that is 30 meters tall each year
You can imagine the cost/benefit
Tree farms help with fragmentation!

7. Problems (and Solutions) in Forestlands
Deforestation (habitat fragmentation)
Can result in soil erosion if not covered (cover crops)
Reforestation – NE contains more forest land that it did in 1900!
Government or Private tree plantings
Story of New York – state bought lands during Great Depression and fixed them!
NE = New England

8. Parks, Preserves, and Wilderness
1870 – individuals from Montana/Wyoming brought land use concerns to Congress which led to…
UN Man and the Biosphere Program – include people!
U.S. Wilderness Act – designates certain areas
Wilderness – the land and ecosystems it supports are protected from all exploitation
Yellowstone

9. Minerals – What Are THEY?
Can be 1 element or 2 or more bonded together (a compound)
Naturally occurring
Inorganic (usually) – no carbon
Orderly internal structure (lattice)
Set chemical and physical properties
In today’s activity and later on we’ll take a look at mining for them!

10. Ore Minerals Minerals that are valuable and economical to extract
Metallic or nonmetallic
In extraction they must be separated from “gangue minerals” (useless) and then again to the target element
Final price must be greater than the extraction/refining costs
Can form in three ways:
Cooling/hardening of magma (sink beneath)
Crystallization from hydrothermal (hot) solutions
Evaporation of water leaves “evaporites” (rock salts) behind
Hydrothermal (hot water) solutions flow through cracks dissolving minerals, which then crystallize out when they have the space

12. Mineral Uses Metals – malleable, durable, and/or good conductors
Combined to make alloys (best of both worlds)
Nonmetals
Gypsum – used to make Sheetrock (wallboard) for homes/buildings
Gemstones – purely for their beauty or rarity!
Stealth fighter aircraft – titanium!