BIOGEOCHEMICAL CYCLES, And HUMAN IMPACT Man, Steve Cutts 3.36

Biogeochemical Cycles Water Cycle (Hydrological) Phosphorus Cycle Carbon Cycle Nitrogen Cycle

THE WATER CYCLE X 1000cubic km

Acid Rain pH of ‘Normal Rain’? ~5.6

Problems Caused by Acid Rain Coal Combustion and Acid Rain 2.04 Acid Rain-DC 2.3 BBC Acid Rain 4.5 Ocean Acidification 6.38

DDT 1962 CH54#7

Persistence, Bioaccumulation, Biological Magnification CH54#7

BIOMAGNIFICATION When substances like mercury and pesticides (herbicides, insecticides) enter a river, etc. from factory waste, the entire food web can be destroyed. Negative health effects STEPS: Persistence: Characteristics of certain chemicals that are extremely stable and may take many years to be broken down into simpler forms by a natural process. Biological Accumulation: Buildup of a persistent toxic substance such as pesticides, in an organisms body. Biological Magnification: The increase in concentration of a persistent toxin in the tissues of organisms at higher trophic levels. (The larger the animal, the greater the accumulation of toxin) HW54-7

the condition in which the growth of water plants takes place in excess amount “Enrichment”

THE HUMAN IMPACT ON ECOSYSTEMS Pollution and Overpopulation can seriously damage the health of an ecosystem (the living and non-living factors in an area). Water Quality Testing 29.13   Dead Zone 2.36 Dead Zones 3.39 Low DO-Puget Sound 4.35 #1 #2 #3

THE PHOSPHORUS CYCLE Needed for: DNA Cell Membr. ATP No gaseous state; released from rocks… released by weathering  

Nitrogen Cycle How organisms convert (fix) unusable nitrogen (N2) in the atmosphere to usable nitrogen to make proteins 1. All organisms need Nitrogen to build proteins and for growth. Our atmosphere is made up of what % of Nitrogen? 2. 78% of the atmosphere is Nitrogen, but organisms cannot use it. The nitrogen needs to be changed (or “fixed”) into a useable form. Why do we need it? How do we get it? 3. Nitrogen fixing bacteria, on the roots of plants, (Legume or bean plants like peanuts, soy, alfalfa) change the nitrogen to a usable form (ammonia/nitrates) Symbiotic Type? 4.Animals then eat the plants/plant eaters to get the needed nitrogen

Legumes Legumes are plants whose roots contain nodules that have nitrogen-fixing bacteria. Used in crop rotation to increase nitrogen in nitrogen-depleted soil Examples: Peanuts, soy, clover

THE CARBON CYCLE

THE GREENHOUSE EFFECT

Acidification of Oceans By 2050, live corals could become rare in tropical and sub-tropical reefs due to the combined effects of warmer water and increased ocean acidity caused by more carbon dioxide in the atmosphere. The loss of coral reefs will reduce habitats for many other sea creatures, and it will disrupt the food web that connects all the living things in the ocean Acid Oceans- The Other CO2 Problem 6.38 Coral Reefs and Climate Change

FOSSIL FUELS Fossil fuels - made from organisms that died millions of years ago and were buried ”non-renewable”, meaning there is a limited supply. Examples: Coal, oil and gas Oil Spills Pose Risk to Ecosystems 1.51

Renewable Resources Examples: Resources that have unlimited supply. Often considered “green” Often do not release harmful pollutants and/or carbon dioxide Examples: Wind, solar, geothermal, hydroelectric (water) *NUCLEAR

The Ozone Layer

Clips Fast Food for Polar Bears 7.29 Bill Nye Crossfire Debate 13:57