Ecology of the Southwest

 Exam 1 – Study Guide

Use this Study Guide to help you organize your notes & your thoughts as you prepare for our first exam.  You should ALSO visit the links to each day’s topic on the Website Syllabus: there are usually questions on each of these pages that you should be able to answer, and many of the “Assess-Goals” questions will show up on the test!

Week 1 - Course Intro. & What is Ecology?

What is Ecology

• Ecology not the same thing as environmentalism (“recyling”)… why not?
• definition…
• most importantly, it is Science, Biology
• what do ecologists do?  - make observations, ask questions, generate hypotheses
  • scientific method
• study of Pattern & Process
• At what levels of organization do ecologists study nature (4 main ones)?
• Species interactions!  Describe/name main ones
• Major questions ecologists ask: “How do distributions of organisms change over space & time?”
• biotic vs. abiotic environment

Ecological Constraints:

• use of hierarchies as organizing tools for complex systems
• organization of biological systems à hierarchies; examples?
• in complex systems, larger scale processes set limits (= constraints) for smaller scale systems below them
• define constraints       
• What = main constraints on ecological systems?
  • At global, regional, & local scale
• Be able to make a concept map (hierarchical) that organizes a set of ecological constraints

Week 2 - What is the Southwest?

Global Climate Patterns:

o    what are the 4 major components of climate?

o    Be able to interpret the climograph figure (Biomes)

§  how do temp. & moisture affect distribution of biomes?

o    Solar insolation – how does it vary over surface of earth?

§  why are some part of Earth warmer or colder than others?

o    What is the cause of the seasons?

o    Global air circulation

·         be able to draw &/or interpret a diagram showing global circulation patterns

·         why are the tropics wet?

·         Why are there deserts at 30^o latitude?? – be able to explain!

·         what can warm air hold?  what does falling air do?  etc….

 Southwest Landscapes & Regional Climate:

o    Landscape features that affect regional climate – in SW = mountains

o    Rainshadows – where & why

o    Landscape features of SW:

·         S. Rocky Mtns.

·         Colorado Plateau

·         Basin & Range

SW regional climate:

o    hot, dry

o    bimodal precip. Pattern – based on the homework assignment, graphing monthly precip.

o    when is it dry in the SW? (which seasons/months)

o    describe precip. types in different “wet” seasons

            How do Mountains affect the 4 major components of climate?

o    changes in precip. & temp. with increasing elevation – WHY?

§  What is “adiabatic (&/or environmental) lapse rate"?

o    N vs. S facing slopes (slope aspect)

Week 3 – The Physical Environment

Features of the (local) physical environment an ecologist needs to be concerned with

Succession

·         Floristic Relay game:

§  Be able to identify characteristics that distinguish early vs. late successional species

§  Recognize that the final community composition is a result of 2 factors: disturbances & species interactions

Disturbance (&) –

·         change is constant: ecological systems vary in space & time

·         disturbance regimes – spatial & temporal characteristics of disturbance

·         frequency & intensity of disturbance

§  the disturbance regime table

·         why do we say “disturbance is a matter of perspective?”

·         effects of disturbance –

·         vegetation recovery

·         thought question:  can the lack of disturbance actually be “disturbing” to an

ecosystem?

Week 4 – Human Ecology

Why Rabbits Have so many babies…

o    the “doubling salary” question (1 penny first day, 2 the second, etc.) – what kind of growth was this?

o    population growth: exponential & logistic (resource-limited)

§  terms in equation to define exponential growth

§  what does each pattern of growth look like?

o    carrying capacity (K) – static or fixed?  Set by what?

o    r vs. K strategies:

o     what are the trade-offs (between # & size of offspring)?

o    human pop. growth

Human Ecology

o    how is it that humans are r vs. K strategists under different conditions?

o    what are the trade-offs between Hunting & Gathering vs. Agriculture?

§  (nutritional, time expenditures, nomadic lifestyle…)

o    how does using an ecological view of humans affect perspectives on H&G vs. Ag.?

o    what causes the shift from K to r-selection in humans?

§  birth spacing

o    implications for human population growth?

§  What kinds of events allowed our population to continue to increase?

§  What event(s) lead to the largest drops in human pop?

§  How have we been able to “raise” the carrying capacity?

Week 5 – …& Other Animals

Why are big fierce animals rare?

o    Leopold’s essay “Odyssey”

§  chemical nutrients (like C) are conserved, & cycle through food chains

§  example(s) of how “X” cycled through the prairie ecosystem

o    the ULTIMATE reason for rarity of top predators…?

·         Energy Flow!!

·         Trophic Levels/ Food webs

·         Energy is lost thru food chains; how many trophic levels can most ecosystems support?

·         What about chemical compounds (pollutants) like DDT? what happens to them as you move up thru food chains?  --à Bioaccumulation!!

Predator-Prey interactions

o    Leopold essays, “Thinking like a mountain”; “Escudilla”

o    “old” views of predators?

o    Leopold’s new view – how did it arise?  (refer also to Beast in the Garden)

o    Types of predator impact on prey species:

• Yellowstone cottonwoods & willows exercise - roles of different species, including wolves, in this example?
• interpreting graphs!!

o    ** predators rarely able to control prey pops.  – prey abundance more likely to

control predator abundance (because of energy flow…!)

o    the latest reasons for rarity of predators…predator control, habitat loss

--- Beast in the Garden questions