The Phosphorus Cycle

• Phosphorous is a valuable resource

• Unstable on its own it bonds with oxygen to form phosphate minerals (PO4)

• Helps build the membrane of your cells (phospholipid bi-layer ring a bell?)

• Is also present in bone, toothpaste and many fertilizers

• It’s estimated that >50% of all the crops grown in the US use some from of P-based fertilizer

The Importance of Phosphorous

Phosphorous Mining Large amounts of Phosphorous are found in sedimentary rocks LIMESTONE!

Thornton Quarry is one of the largest limestone mines in the WORLD The quarry is 1.5 miles (2.5 km) long, 0.5 miles (1 km) wide, and 400 feet (125 m) deep.

These exposed walls are prone to weathering by the elements and the runoff leaches into the surrounding water table

•Used in Agriculture-- Used in the fertilizer (lime) give plants access to a naturally limiting nutrient

• Home usage-- soaps containing phosphorous

Anthropogenic usages of Phosphorous

•SINCE EVEYTHING RUNS DOWNSTREAM….

•Phosphorous is a limiting nutrient in most aquatic ecosystems•So it causes…

Eutrufication!!!

Ecosystems respond to disturbance

• Disturbance- An event caused by physical, chemical or biological agents that results in changes in population size or community composition.

• Common human disturbances include: Clear cutting, draining wetlands, building of roads, releasing pollutants into the air and water and the introduction of a new non-native species into an ecosystem.

•Natural disturbances can also disrupt ecosystems•Storms •Forest fires•Earthquakes •Volcanoes •Mud slides

•What happened to these wetlands in Louisiana after Hurricane Katrina? Pg. 74

Resistance versus Resilience

• Define: Resistance, Resilience and Restoration ecology

Watershed Studies• Read pg. 74 ‘Watershed Studies’

• What is a watershed?

• What was the purpose behind the watershed study that happened at Hubbard Brook?

• What biotic and abiotic factors were monitored in the case study explained in the text?

• Explain how the clear-cut watershed and the control watershed were different. How were they similar?

• What information about the ecosystem were researchers able to gather about the two ecosystems over time?

The Intermediate Disturbance Hypothesis

• The intermediate disturbance hypothesis- states that ecosystems experiencing intermediate levels of disturbance are MORE DIVERSE than those with high or low disturbance levels.

• What are the three ways to measure biodiversity?

Put this graph in your notes!!!!

•Intrinsic Value vs. Instrumental Value This mountain valley is so

beautiful! It should be preserved for the wildlife and the enjoyment of ALL

living things

There is GOLD in them there hills!

dynamite the lake and we will be RICH!

•Instrumental value vs. intrinsic value

•Instrumental value is seeing nature as having worth as a tool to accomplish a goal •“This big tree will build me a big house”

•Intrinsic value is when nature has a value beyond monetary wealth or gain. •“This big tree is beautiful in this forest and frovides a home for other species.”

•Both are important to understand when talking to people about the ‘value’ of nature

Instrumental Values of Ecosystems• Read pg. 77-80 and explain how the following

would be scene as instrumental values of an ecosystem.

• Provisions-

• Regulating services-

• Support systems-

• Resilience-

• Cultural services-

Homework!

Due Wednesday:

• MCQ’s 1-15 on pg. 82-83

• Go to pg. 136 + 137 in your book and answer the following questions using figure 5.20 and 5.21

1. 1) Which tree species showed the greatest resilience in the southern US during the last glacial maximum?

2. 2) In the present day which tree species has demonstrated the greatest resistance to the increasing temperatures in the northern most reaches of North America?

3. 3) Use evidence from figure 5.21 to explain resisistence and