- ~30% of world’s fresh water used by people
- ~70% for irrigation
- ~20% in industry
- ~10% residential
- Deficit is not noticeable (made up by aquifer overpumping)
- Problems most serious in these countries and/or areas: China, The Indian subcontinent, The Middle East, North Africa, North America
- In 18 countries, water supplies are insufficient
- By 2050, water supply insufficient in ~39 countries
- ~1.7 billion people will have too little water to fulfill basic needs
- Area that is super saturated
- with water, in which water can be drawn out of it.
- Rate at which aquifers are replenished.
- Frequently exceeded by our water use. Rates vary quite a bit, as do the amount that water is being removed.
- We draw about 2/3 of the recharge rate out of local aquifers.
Were being recharged in the past, however the weather situation has changed.
Black Hills Aquafers
- Inyan Kara
Reducing flooding and damage from flooding
- Don’t remove or “reclaim” wetlands
- Don’t remove upland vegetation
- Don’t remove streamside vegetation
- Don’t channelize streams
- Don’t build in floodplains
- Occurs where you irrigate arid areas.
- Brings salt out of the gound, turning it into a salt pan.
- Vegetation doesn't recover in this area.
- Supplies water to about 20% of the area.
- Recharge rate extremely low.
- Most of the recharge has come from ice melt from the last iceage.
- Conversion of land to corn should increase water use.
Glacial lakes: “Prairie Potholes”
- This region is the biggest region for the production of waterfowl for the country.
- Has suffered a reduction of about 50% of ponds and 50% of water fowl populations.
- The ponds are disappearing because of drought.
Point vs Non-Point Pollution
- EPA Regulations Point-Source Pollution (Can be followed back to a source.)
- Most of the pollution in the US and worldwide is from non-point sources (Running across the land, carrying pollutants.)
- Non-Point is more common.
Five parts of the nitrogen cycle
- Nitrogen Fixation
Percentages or organic matter in the ecosystem.
- 25% of the biomass in this ecosystem is all below ground.
- Most is usually found in the soil.
- When the soil gets removed, you lose a lot of the organic matter.
- Reducing the nutrient content is also a bad thing.
- The below ground biomass doesn't include burrowing animals, mostly means microorganisms and roots.
Most Important Nutrients Used by Plants
- Soil is made during the process of the weathering of rock.
- When glaciers recede, they only leave bedrock.
- The only thing that can colonize this is lichen.
- Lichen produce carbonic acid which eats the rock away and forms really primitive soil.
- Only Nitrogen-fixing plants can live in young soil.
Mixture of Clay (10-30%), Silt (30-50%) and Sand (25-50%)
6 Soil Layers
- Solid Parent Material
O – Horizon
- Made up of humus (Decomposing matter).
- Is where most organisms that live in soil are found. These organisms break down the humus.
- Fairly rich with nutrients.
- Richest mixture of nutrients are found on the bottom of this horizon.
- Water tends to pull metals out of this horizon into deeper horizons (known as leaching)
- Accumulated organic matter, more leached material at the bottom.
- Plants sink their roots usually only through the O and A horizon.
- If top soils are removed, difficult to grow things here.
- Some plants can work with it, lot of them cant.
- Lot of metals present in this horizon.
- Much more resistant to leaching, but full of leached material.
Lots of minerals accumulate here.
- Mollisols: Fertile, dark, soils of temperate grasslands (The richest soil types in the world, They have a deep A Horizon)
- Oxisols: Soils of tropical and subtropical rain forests (Humus broken down rapidly in O horizon, A horizon is thin)
- Alfisols: Found in forests of the temperate zones (Moderately well developed O, A, E, and B horizons)
- Aridisols: Soils of drylands and deserts of the world (Sandy with poor water retention, Known as salic soils)
- Spodosols: Soils of northern coniferous forests (Acidic O horizon, Leaching is common)
Types of Soil Damage
- Mineral Depletion
What is biodiversity?
- Number of Species (species richness)
- Genetic diversity within a species (# of individuals, # of populations)
- Ecological diversity (diversity of habitat)
- Ecosystem Services (Pollination, pest control, flood services)
- Genetics (genetic pool of resources: crops, gmo, source of new crops)
- Research Potential (research of all kinds needs genetic stock)
- Teaching potential (natural teaching lab)
- Utilitarian (Products from the wild)
- Spiritual/Religious ("piece of mind", recreation)
- "Normal" rates derived from fossil record
- Called "background extinction rate"
Current Rates of Background Extinction
- 10s to 10s of thousands of times background rates
- Compared with any of the rates of the five mass extinctions
- As a result, study of mass extinctions is important
What causes extinctions?
- Habitat alteration
- Invasive species
Causes of Extinctions: Habitat Alteration
- Habitat loss
- Habitat conversion
- Habitat fragmentation
- Habitat degradation
How to decide what to conserve
- Endangered habitats
- Biodiversity hotspots
- ~2000/5700 in decline
- Amphibians as indicators
Reasons for Frog Declines
- Introduced predaceous fish
- Other introduced species
- Climate change
Peculiarities of honeybees
- The proboscis reflex
Threats to honeybees
- Varroa destructor (mites)
- Nosema ceranae (parasite)
- Colony collapse disorder
- Alfalfa leaf-cutting bee
- Blue Orchard bee
- Hornfaced bee
- Syrphid flies
- Bluebottle flies
Decline in Fish Size
- Oceans warm and fish move more
- Increases oxygen demand
- Fish gill size selected for via natural selection
- Result: Decline in size and move to cooler waters.