NRCS/CIG Landscape Carbon Model

User level:  2   What is this?

The Landscape Carbon Model (LCM) calculates total soil-carbon sequestered and sequestration rates, at a landscape scale, under different rangeland management regimes. For example, one can compare differences in sequestration as a result of changing livestock stocking rates or differences in grazing intensity.

This model integrates the PATH Landscape modeling tool and the Century soil model. The PATH modeling tool assists land managers in predicting how vegetation may change over time, in response to possible future natural processes and anthropogenic activities. These changes in vegetation structure and composition are reflected in changes in soil-carbon sequestration rates. The LCM utilizes the Century soil model to estimate the soil-carbon sequestered, per acre, for each vegetation type. The model then integrates these two results to provide estimates of total carbon sequestered, over the simulation period, for the entire assessment area.

How It Works

The Century soil carbon model can be used to estimate the potential for carbon sequestration in rangeland soils. However, parameterizing the Century model is not a trivial task. While Century comes with tools to help construct the necessary parameter files, using these files to set up, execute, and compile results over different scenarios is cumbersome and time consuming. Additionally, the Century model is difficult to apply to large, diverse landscapes that may experience significant changes in land cover over the course of a model simulation due to management or disturbance events. While these kinds of changes can be modeled to a degree within Century, it involves complex parameter and scenario files.

The NRCS/CIG Landscape Carbon Model web tool was created to make it easier to implement Century in the context of dynamic landscape modeling. In this modified modeling environment, a series of PATH Landscape state and transition models (STMs) are applied to management/disturbance scenarios to simulate how a landscape may change over time. Century is run on the detailed output of the PATH Landscape models to estimate how soil organic carbon changes in the study area in response to a given management scenario.

Estimating soil carbon storage potential for a landscape over time requires running: 1) the Path Landscape models for user defined management/disturbance scenarios, and 2) the Century model for each STM state with parameter files that match the Path Landscape scenarios. The NRCS/CIG Carbon Model simplifies this process by taking the output from the Path Landscape model and the corresponding parameter files for Century and automating the running of the Century model and compilation of the results.

Example Scenario Files

Below are some example files that can be downloaded and then used with the Carbon Model tool. Included in each download are the path landscape output .csv file, the four .100 files, and the .sch schedule files. All these example files were created for the Flattop Ranch, Idaho. Once you have downloaded the .ZIP file, you can click the Choose File button and select the example file.