1. Course Progress
NSI

2. Topics Covered Logic Reasoning and Evidence Sampling
Bias, variance and making inferences
Statistics
Making probability statements for 3 types of data comparisons
The nature of science
Hypotheses, refutability, expert opinion

3. Reject or accept hypothesis
The scientific method
Observation
Hypothesis ?
Design test
Conduct test
Manage & analyze data
Reject or accept hypothesis
Interpret results
Communicate findings

4. Reject or accept hypothesis
The scientific method
Observation
Hypothesis ?
Design test
Conduct test
Reject or accept hypothesis
Communicate findings
Manage & analyze data
Interpret results

5. Next steps…
1. Critical analysis and exposure to science-related issues
2. Formulate a hypothesis and design a study to test it
3. Integrate all aspects of the scientific method into your final project

6. Water quality in stream ecosystems

7. A complex system

8. The Systems Approach
A system is any phenomenon having at least 2 separable components and some interaction between them.
Properties:
1) They are modular, i.e. can be separated into components
2) They are hierarchical, i.e. each system is part of a hierarchy of other systems

9. wilderness area
wetlands
lakes
forests
streams
…..
stream 1 ecosystem
stream 2 ecosystem
stream k ecosystem
abiotic
biotic
H20 quality
external factors
arthropods
fish
Micro-organisms
plants
temp pH
dissolved
particulates
micro-
macro-
beetle
mayfly
stonefly
caddisfly
…..
individual 1
individual 2
Individual k
“Each level finds its explanation in the levels below, and its significance in the levels above” -Bartholomew

10. Once the components are identified, we can then create a model of how the components of interest are related.
A model is any representation (simplified) of a real system.
Models are used for:
1) Understanding
2) Prediction
3) Management

11. Building a simple model
Fertilizer run-off
Fish
Algae
Macroarthropods

12. ..…levels of resolution Fertilizer run-off Fish Herbivorous insects
Algae
Predatory insects

13. Streams drain watersheds

14. Channel & Riparian Zone

15. Water Quality Riparian zone management Pollution Erosion Sewage
Industrial discharge
Household discharge
Agriculture
Exposure to the sun
Chemical
Thermal
Particulate pH
Dissolved compounds
Temperature
Dissolved gases (*O2)
Turbidity
Microbes

16. Bio-indicators: “EPT Diversity”
Ephemeroptera
(mayfly)
Plecoptera
(stonefly)
Trichoptera
(caddisfly)

17. Other potentially useful bio-indicators:
Odonata: dragonflies & damselflies

18. Other potentially useful bio-indicators:
Water mites (Acari: Hydrachnida)

19. A giant water bug infested with water mites

21. Larval Attachment:
A resilient, accordian-like “stylostome” is cemented to the host cuticle and serves as a feeding tube.
X volume increase!!!
Photo from Abro (1984)

22. Other common (and more tolerant) aquatic insects
Coleoptera
(beetles)
Hemiptera
(true bugs)
Diptera
(true flies)

23. Summary 1) Breaking down complex systems into manageable components
2) Creating a model consisting of components and relationships between them
3) Using aquatic arthropods as biological indicators of water quality

24. Rain Beetle

25. Field trip (Monday / Wednesday)
Rain or shine!
Bring:
warm clothes
rain gear
something to write with & something to write on
Vans leave at 9am sharp(!), between Cramer and Smith Halls (on Broadway).

26. References
Hall Ecosystem modeling in theory and practice: an introduction with case histories. Wiley & Sons, NYC
Orians Micro and Macro in ecological theory BioScience 30: 79
Walters Systems ecology: the systems approach and mathematical models in ecology.
EPA Volunteer stream monitoring: a methods manual. Available Online,
Photos: Several websites including Ken Gray Insect Photo Gallery,