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)