Lab 3. Overview Instructor collects lab. 2 write ups and

checks pre-labs. in lab notebook Discussion of graded termite write up

Overview of Ecological Communities, Plant Structure, & Soil Microorganism Procedure.

In-class plant identification with key

Gather plant species richness data in field & return to lab room.

Prepare microbial plate samples using serial dilution (no burners until instructor in room).

Exercise due in Lab 4 discuss. & questions

Communities Community = A group of SPECIES living in

the same area that have the potential for interaction.

Species Richness = number of SPECIES in a given area (community).

Plant Structure Review

Simple vs. Compound Leaves

trifoliatebipinnate

Leaf Blade Shape

heart shapedoval

leafarrange-

ment

Common Campus Forbs

Convolvulus arvensisbindweed

Malva neglectacommon mallow

Medicago sativaalfalfa

Common Campus Forbs

Ambrosia psilostachyawestern ragweed

Taraxacum officinaledandilion

Sanquisorba minor

salad burnet

Common Campus Forbs

Kochia scopariakochia

Chenopodium albumlambsquarters

Quadrat – Sp. Richness Sampling

m2

m2

m2

samples = 2 2 1

m2

2 mean = 1.75

Serial Dilution Serial Dilution = Sequentially reducing

concentration by the same factor (usually a factor of

10). - allows separation of individual cells (causing separation of the derivative microbial colonies).

Sterile Technique =

Keeping

environmental

microorganisms out

of a sample or area.

1gSoil

1 ml

1:1000dilution

1 ml 1 ml

soilwater

1:10dilution

1:100dilution

NA

NA

NA1:10 Plate

1:1000 Plate

1:100 Plate

Transfer 150 μl (0.15 ml) from dilution tubes to each plate and spread.

Reminders Before the Field READ the instructions () in the manual

Develop hypothesis now.

Count the number of SPECIES (kinds) of FORBS in each quadrat.

(NOT individuals and NOT grasses)

Identify the most common species in the areas to be sampled (bring manual).

Decide what is “in” a quadrat & sample randomly.

When finished, return to the laboratory.

Obtain your unpaired T-test P-value using the online site on the course website –Exercise.

Reminders for the Lab READ the instructions () in the manual

Be careful with the Bunsen burners.

Please do not set yourself on fire.(Tie long hair back. No loose dangling clothing.)DO NOT use burners without the instructor present.

Do not roast the spreaders in flame. Pass through quickly. You just need to see a little flame on the spreader (& allow to go out).

Do not put a hot spreader into the alcohol.

Spread samples on the medium, not on the lid.

LABEL YOUR PLATES (dilution and soil A or B)