Course Progress NSI

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

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

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

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

Water quality in stream ecosystems

A complex system

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

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

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

Building a simple model Fertilizer run-off Fish Algae Macroarthropods

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

Streams drain watersheds

Channel & Riparian Zone

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

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

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

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

A giant water bug infested with water mites

Larval Attachment: A resilient, accordian-like “stylostome” is cemented to the host cuticle and serves as a feeding tube. 300-600 X volume increase!!! Photo from Abro (1984)

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

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

Rain Beetle

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).

References Hall 1997. Ecosystem modeling in theory and practice: an introduction with case histories. Wiley & Sons, NYC Orians 1980. Micro and Macro in ecological theory. BioScience 30: 79 Walters 1971. Systems ecology: the systems approach and mathematical models in ecology. EPA 1997. Volunteer stream monitoring: a methods manual. Available Online, http://www.epa.gov/volunteer/stream/index.html Photos: Several websites including Ken Gray Insect Photo Gallery, http://www.ent3.orst.edu/kgphoto/showall.cfm