CANVEG

Criterion

Explanation

Landscape scale biophysical 1-D multilayer gas exchange model between biosphere and atmosphere for CO₂, ¹³CO₂, water, sensible heat, ozone, sulfur dioxide, and isoprene flux densities using coupled micrometeorological and physiological modules.

Model Domain

General

Developer

University of California, Berkeley: Professor Dennis D. Baldocchi.

Hardware computing requirements

Not specified

Code language

Visual C++

Original application

Original model (CANOAK) was used to calculate fluxes of carbon dioxide, water vapor and energy between vegetation and the atmosphere in forest systems.

Public/proprietary and cost

Public, no associated cost for use.

Physically or empirically based

Mechanistic model based on net ecosystem exchange flux partitioning.

Mathematical methods used

Uses scalar conservation, algorithms, and sub-models to account for: micrometeorology, turbulence, diffusion, radiative transfer, net leaf exchange (photosynthesis, respiration, stomatal conductance and transpiration), soil exchange (soil and root respiration and evaporation). Additional information can be obtained from Baldocchi and Harley (1995), Baldocchi (1997) and Baldocchi and Meyers (1998).

Input data requirements

Photosynthetic photon flux density, air temperature, wind speed, relative humidity and CO₂ concentration, leaf area index, maximum carboxylation rate, leaf angle orientation, spatial dispersion index and canopy height, soil temperature at a deep reference point.

Meteorological and soil data easily obtained from public databases, canopy characteristics can be assimilated with some effort from peer reviewed sources.

Outputs

Micrometeorological module output – environmental variables such as leaf and soil energy exchange, turbulent diffusion, scalar concentration profiles and radiative transfer within the canopy

Physiological module output – leaf photosynthesis, stomatal conductance
and respiration from leaf, bole, soil and roots.

Complete model output – Gross primary productivity, net ecosystem exchange, respiration of total ecosystem and individual components for CO₂, H₂O and sensible heat.

Pre-processing and post-processing tools

No processing software provided.

Representation of uncertainty

Currently no error propagation or uncertainty limits integrated into model framework. Uncertainty of various computational methods have been evaluated using uncertainly in data input, fractionation factors, model parameters and making multiple iterations (Oikawa et al., 2017).

Prevalence

Currently used exclusively by individual modelers in academic institutions.

Ease of use for public entities

Moderate to difficult: experience with Visual C++ required.

Ease of obtaining information and availability of technical support

No commercial technical support, only correspondence with individual modelers can provide support.

Model and Source code availability

No model or source code readily available to public. Source code available upon request from developer.

Status of model development

Model developed and available for use. Future updates include expanding CANVEG model from ecosystem scale to continental and global scales using a more simplistic version of the model (to be named BESS model).

Challenges for integration

Integration challenges may include difficulties integrating with other models requiring 2-D or higher spatial resolution.