Monday notes and questions

Class Notes 06/07/2010

Climate Review

· Earth and the Sun

o Earths tilt on its axis stays the same, which causes Northern and Southern hemisphere weather differences.

o Leads to changes in day length and temperature seasonality.

o Jet Stream has cold air above (north) and warm air below (south)

§ Polar front is the intersection of the different temperature air.

o Boulder is very seasonal

§ Jet stream crosses over frequently driving Boulders climate, changing it from week to week.

§ Frontal precip. In winter, thunderstorm precip in summer

o Jet Stream is fairly far north in summer

o As air temperature decreases relative humidity increases, and when it gets high enough precipitation forms.

o As air temp increases relative humidity decreases causing hot dry air, which leads to evaporation increasing.

§ As westerly winds hit the mountains and descends the leeward side the temperature increases bringing hot dry air and lots of evaporation.

§ Boulder is in a rain shadow

o If winds switch then you get up slopes that bring precipitation.

o As you go up in elevation you get cooler and wetter weather.

o Lyons has Rabbit Mountain, which acts as a double rain shadow.

o Within each elevation there are microclimates

§ North face of a hill gets less sun than South face.

· Vegetation Zones

o Grasslands 5,500 ft

§ Mainly short grass prairie

§ Riparian forest (willow, cottonwood)

§ Disturbances – Fire, Flooding

· Fire adapted with cones to protect and high root amounts.

· Trees want flooding to clear banks for seeds.

o Lower Foothills Ecotone (grass/lower montane)

§ Looks generally like grassland with patches of Ponderosa Pines

§ Disturbances – Fire, Bison, Elk

· (Now fuel is build up fire could be worse than in past)

o Lower Montane Forest – 5,900 – 8,000 ft

§ South facing slope is sunnier and dryer (ponderosa pines)

· They compete for water, which makes the plants shorter and more bush like. (5 – 40 trees per acre)

§ North facing slope has more moisture but must compete for sun.

· Tall trees with thick bark and narrow.

o High frequency, low severity fires 5-30 per year.

o Trees self prune their lower branches and have thick bark to protect.

· Disturbances – Fire, Bugs, Beetles, Mistletoe, humans

o Upper Montane 7.500 – 9,000 ft

§ Lodge pole Pine, dug fir, aspen.

§ Some open meadows, wetter with elevation.

§ Denser structure

§ Disturbances – Fire, Beetles, Avalanche

· Fire history – mixed frequency, mixed severity

o Aspen need fire, pop up frequently after fires.

· Hard hit by Mountain Pine Beetle outbreak

o Now starting to hit more of a range of trees, different sizes, ages, and health.

o Subalpine 9,000 – 11,500 ft.

§ Lodge pole, aspen, subalpine fir, englemen spruce

· Spruce has spiky hard needles, fir has flat soft needles

· Tends to be very patch sections of different age stands and species compositions.

· Disturbances – fire

o Intense fires, kill everything every 150 -200 years

§ Hard to reproduce

§ Wild land Urban Interface

· Some houses (urban) mixed in with the wildlife, makes it difficult to allow fires.

o Alpine Tundra 11,500 up

o Historic Range of Variability – Objectives – return ecosystem processes such as fire variability to original (pre-European) range.

§ Study tree rings and ecosystem to find out what original conditions were like before European interaction.

· Aldo Leopold

o Aesthetic Conservation

§ Should be environmentally conscious when using nature.

· High intrinsic values

· We are taking value down by letting people in so easily

o Impacts such as roads and erosion

· Inaccessibility makes it valuable

· Trophy – brought population increase, with this made fewer trophies possible and more desired.

· Auto Camping – very against this trend of driving to an area and camping, usually leaves trash and destroys site.

o Wildlife in American Culture

§ Indians needed wildlife for everything; they used it in every aspect of their lives.

· Now things have shifted and we do not necessarily need wildlife.

§ 3 Values

· Remind us of origin

· Food chain

· Sportsman ship

§ Gadget – sporting goods dealer – used to be self-reliance, now we don’t need and hunt only for sport.

§ Need to find a middle ground between 1 shot 1 kill and gadget hunting.

o Wilderness

§ Need to preserve wilderness, defend it.

§ Must be educated

§ Little remains of older wilderness, no virgin wilderness left.

· Need to learn how nature works and not use so many chemicals and pesticides.

§ National Parks are not enough

§ Need to educate people on how to defend the wilderness.

o Ethics

§ Need Co-operation

§ Land ethics – include soil, water, plants, animals and the land in the community

§ Role of Homo sapiens from conqueror of land to member and citizen of it.

§ Land has changed over time with settling, the landscape is wrecked.

§ Need to step up education, but not just for what is profitable for you and your land, but all land.

· Not only self interests.

· Education needs to precede rules

§ Land and nature needs to be thought of not only as economic values but more philosophically.

Questions:

1. As air temperature relative humidity .

a. Decreases, increases

b. Falls, raises

c. Increase, decreases

d. Increases, increases.

2. Rabbit Mountain acts as what for Lyons?

3. Why are the trees on the North face taller than the trees on the South face of a hill?

3. Why is it necessary for fires to occur?

4. Why does Leopold not favor auto camping?

5. What are the main differences between hunting and gathering, and gadget hunting?

6. What are Leopold’s 4 questions?

7. Name the different Vegetation Zones.

8. Explain “Historic Range of Variability”. Why is this concept useful to land managers?