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

Matt Miller

Matthew.p.miller-1@colorado.edu

OutlineOutline

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 Long Term Ecological Research (LTER)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

http://lternet.edu/

Mission of LTER NetworkMission 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 SiteNiwot Ridge LTER Site

Approximately 25 miles west of Boulder Alpine tundra environment (biome) Includes the Green Lakes Valley http://culter.colorado.edu Research topics

– Meteorology/Climatology– Hydrology– Biogeochemistry– Biology

Niwot Ridge

Continental Divide

Green Lakes Valley

Defining Characteristics of Defining Characteristics of BiomesBiomes

SoilClimateGeographyBiologyHuman Influences

Soil

Climate Geography

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/ClimatologyMeteorology/Climatology

Air TemperaturePrecipitationRelative HumidityWind Speed/DirectionSolar Radiation

HydrologyHydrology

Stream DischargeSnowpack Ablation

– Loss of snow pack

Snow Water Equivalent– Water content obtained from melting a defined

sample of snow

Soil Moisture

BiogeochemistryBiogeochemistry

Definition (unofficial): The study of how biology, chemistry, and geology effect element cycles in nature

Snowpack ChemistrySurface Water QualityAtmospheric N loadingMicrobial Respiration

BiologyBiology

Plant Species Composition (terrestrial and aquatic)

Small Mammal Herbivore StudiesFossil Insect AssemblagesSoil Microarthropod DensitiesAbove Ground Phytomass

Example: Tracing Carbon Example: Tracing Carbon Flow Through a SystemFlow 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 Biological pathways of Carbon TransformationTransformation

Respiration

C6H12O6 + 6O2 6CO2 + 6H2OPhotosynthesis

6CO2 + 6H2O C6H12O6 + 6O2

Where Does Carbon Come Where Does Carbon Come From/How Does it Change From/How Does it Change

Forms?Forms?Burning of Fossil FuelsBreakdown of Organic Matter (Respiration)Atmosphere (Photosynthesis)HerbivoryPredation

Human Impact?Human Impact?

Sources of Carbon to Aquatic Sources of Carbon to Aquatic SystemsSystems

Autochthonous– Carbon synthesized within the lake or stream

Allochthonous– Carbon synthesized within the drainage basin

and brought to the stream

Tracing Carbon through Tracing Carbon through Aquatic SystemsAquatic 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 As Carbon moves downstream how is it downstream how is it

transformed?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 streamAreas 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 How Do we Trace the Flow Paths?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 MessagesTake Home Messages

Long term data collection is essential to understanding ecological processes and human impact (e.g. CO2 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).