Changes in Terrestrial Carbon Storage in Russia as a Result of Recent Disturbances and Land-Use Change

Principal Investigator: R.A. Houghton, Woods Hole Research Center

Co-Principal Investigator: Olga Krankina, Oregon State University

David Butman, Tom Stone and Peter Schlesinger, The Woods Hole Research Center

OVERVIEW:

The carbon balance of northern mid-latitude terrestrial ecosystems is uncertain, yet important for predicting future rates of CO2 increase in the atmosphere. Analyses based on atmospheric data and models show a net terrestrial sink that ranges between 3.5 and 0.7 PgC/yr in northern mid-latitudes (Tans et al. 1990; Ciais et al. 1995; Rayner et al. 1999; Bousquet et al. 1999a,b, 2000). Analyses based on forest inventories are lower but also variable, especially for Russia and the former Soviet Union, where estimates of carbon balance range between a source of 0.5 PgC/yr and a sink of 1.02 PgC/yr (review of 15 studies by Shvidenko et al. 1996). As Russia represents the largest political unit in the northern hemisphere and contains the largest stocks of terrestrial carbon (Apps et al. 1993, Dixon et al. 1994), it is important to determine the current carbon storage and the net flux of carbon for this country.

Landsat 7 ETM+ Image with Forest Stand Polygons

We are working to determine the current distribution of carbon storage in Russia and changes over time with an approach that integrates forest inventory data, results of ecological studies, historical data on land-use change, and a combination of Landsat and MODIS data and products.

The forest inventory system in Russia has collected consistent and detailed stand level information on millions of hectares annually over the last decades. The large variation in carbon budgets based on these inventory data results from the manner in which the primary inventory data (data from individual stands) are aggregated for regional and country-wide estimates. We shall not use the aggregated totals but, rather, the primary stand data to calibrate Landsat ETM+ and TM scenes in 15 locations throughout the country. These locations will be distributed among 15 separate ecological vegetation zones, along both an east-west and north south plane.

Major Vegetation Zones of Russia based on Kurnaev at. al. (1998)

We have divided Russia into 5 vegetation zones: Northern Taiga, Middle Taiga, Southern Taiga, Temperate, and Forest Steppe. In addition we divided Russia into 4 regions: European Russia, West Siberia, East Siberia, and the Far East. It is our hope that by these divisions we will be able to distinguish vegetation characteristics unique to a particular region and time within landsat data.

We will scale-up these Landsat classifications to the entire Russian territory with MODIS data, and use the coverage to determine the current rates of disturbance, based on the areas of disturbed forests (burned, dead, clear-cut) and rates of regeneration in each ecosystem.

biomass The technique we are using was developed by Cohen et. al. as part of the Forest Science Lab at Oregon State University, and the United States Forest Service Station in Corvallis, Oregon. The technique involves an interesting mix of spectral and spatial statistical analysis. It is our hope that from a basic extraction of spectral reflectance, we can use Canonical Analysis to uncover relationships between the biomass values calculated from the forest inventory data, and the spectral data. If a significant relationship exists, we will use Reduced Major Regression analysis to model biomass across a particular landsat scene for a particular time. It remains our hope that these biomass models can scale from individual Landsat 7 ETM scenes to various MODIS products covering the expanse of Russia. We are investigating various MODIS products for the exercise: MOD09A1 8-day surface reflectance, MOD09Q1 8-day surface reflectance 250m, MOD43B4 BRDF-adjusted 16-day surface reflectance, and MOD44 %Tree Cover 32 day composites.

MODIS BRDF Adjusted Reflectance Data for Russia (Click for High-Resolution Poster)

We will also determine rates of land-use change for the period 1700 to 2000 with tabular data from Russian agricultural and forestry statistics and determine from forest inventory data and the ecological literature the average biomass and rates of growth and decay following disturbance of the major ecosystems of Russia. Finally, we will calculate with a dynamic bookkeeping model (Houghton et al. 1999) the annual flux of carbon between Russia and the atmosphere as a result of changes in land use and fire over the last 300 years.

The proposed work addresses one of the priority issues of the USGCRP and a research area of the NASA ESE program for 2001 and beyond: Carbon Cycle Science. The work will identify, characterize and quantify sources and sinks for carbon (current and past) for a very large and important region of the world.

Carbon Accounting Model Schematic