Experimental Design

Mesocosm Facility
54 minimally disturbed soil monoliths of 2.1-m² surface area, 60-cm depth placed
in insulated plastic tanks in a large field
2 peatland ecosystem
- bog
- fen
3 heating treatments
- ambient
- ½ power with overhead infrared lamps (~ 40 W/m²⁾
- full power with lamps (~ 85 W/m²⁾
3 water-table treatments
- +1 cm
- -10 cm
- -20 cm

Fully crossed factorial design with 3 replicates. Began experimental manipulation
in July 1994.

Sampling Protocol

• Continuous monitoring of heat flux, net radiative input, photosynthetic active radiation (PAR), soil moisture, and soil temperature in all plots.
• Closed water budgets allow for the determination of actual evapotranspiration (AET).
• Input/Output budgets for N, P, and DOC.
• Nutrient availability with resins.
• Above ground net primary production (NPP) using species-specific allometric equations.
• Below ground NPP with root in-growth cores.
• Nutrient uptake in plants.
• Microtopography and peat accretion.
• Multiple methods of plant canopy characterization (canopy geometry, light extinction profiles, NDVI of whole canopy).
• Net ecosystem respiration (NER: CO₂ + CH₄) with static chambers.
• Instantaneous net ecosystem production (NEP) with flow-through chambers and infrared gas analyzer.
• Gross primary production (GPP) can then be calculated (GPP = NEP + NER).
• Development of a treatment-specific carbon exchange model based on the above variables.

Energy Budget