Niwot Ridge-Green Lakes Valley LTER Niwot Ridge-Green Lakes Valley LTER Site Matt Miller

Outline Background information on Long Term Ecological Research (LTER) Background on Niwot Ridge LTER (NWTLTER) site Monitoring data collected at Niwot Ridge in relation to biome characteristics Example of research in the Green Lakes Valley Pictures Note: Most information taken directly from LTER and NWTLTER web sites

Long Term Ecological Research (LTER) 24 Sites including Antarctica, Puerto Rico, and the United States Established in 1980 by the National Science Foundation (NSF) Network of over 1000 scientists

Mission of LTER Network Understanding ecological phenomena over long temporal and large spatial scales Creating a legacy of well-designed and documented long-term experiments and observations for future generations Conducting major synthetic and theoretical efforts Providing information for the identification and solution of ecological problems

Niwot Ridge LTER Site Approximately 25 miles west of Boulder Alpine tundra environment (biome) Includes the Green Lakes Valley Research topics –Meteorology/Climatology –Hydrology –Biogeochemistry –Biology

Niwot Ridge Continental Divide Green Lakes Valley

Defining Characteristics of Biomes Soil Climate Geography Biology Human Influences

Soil ClimateGeography Biology Human Influences Not only do these variables determine the biome in a given area, but each variable has an effect on all other variable. Therefore, it is hard to study one variable without considering the others

Meteorology/Climatology Air Temperature Precipitation Relative Humidity Wind Speed/Direction Solar Radiation

Hydrology Stream Discharge Snowpack Ablation – Loss of snow pack Snow Water Equivalent – Water content obtained from melting a defined sample of snow Soil Moisture

Biogeochemistry Definition (unofficial): The study of how biology, chemistry, and geology effect element cycles in nature Snowpack Chemistry Surface Water Quality Atmospheric N loading Microbial Respiration

Biology Plant Species Composition (terrestrial and aquatic) Small Mammal Herbivore Studies Fossil Insect Assemblages Soil Microarthropod Densities Above Ground Phytomass

Example: Tracing Carbon Flow Through a System Carbon is essential to all life! Where does Carbon come from? How does Carbon change forms? If the Carbon is in water we need to understand how the water moves (hydrology).

Biological pathways of Carbon Transformation Respiration C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O Photosynthesis 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2

Where Does Carbon Come From/How Does it Change Forms? Burning of Fossil Fuels Breakdown of Organic Matter (Respiration) Atmosphere (Photosynthesis) Herbivory Predation

Human Impact?

Sources of Carbon to Aquatic Systems Autochthonous –Carbon synthesized within the lake or stream Allochthonous –Carbon synthesized within the drainage basin and brought to the stream

Tracing Carbon through Aquatic Systems Once in the stream what happens to the Carbon? If looking at Carbon in aquatic systems it is necessary to understand the hydrology of those systems

As Carbon moves downstream how is it transformed? Decomposition of Organic Matter (respiration) Uptake and incorporation into organic matter Excretion Change in Trophic Levels (predation) Change in Oxidation State/Chemical Structure (abiotic or biotic) Main Point: What you see downstream is a product of what is happening upstream

Areas of flow in a stream In a stream system there are two main areas where water flows –The Main Stream Channel –The Hyporheic Zone “The Saturated interstitial areas beneath the streambed and into the stream banks that contain channel water to the depth to which overlying stream water actively infiltrates by advection” –Wetzel, 2001

How Do we Trace the Flow Paths? Tracer Experiments –Add a non-reactive (i.e. salt) or reactive (i.e. organic matter) to a stream –Measure concentrations of the tracer at points downstream in the main stream channel as well as in the hyporheic zone

Take Home Messages Long term data collection is essential to understanding ecological processes and human impact (e.g. CO 2 data). Communication between researchers studying various aspects of any given system is essential (e.g. C flow and respiration). Need to consider all possible effects on a system (e.g. atmospheric N deposition in restricted watershed).