NAFORMA process and biophysical results

Abstract

Tanzania has undertaken a National Forest Inventory popularly known as National Forestry Resources Monitoring and Assessment (NAFORMA). The selected statistical framework was double sampling for stratification. All together there were 3,349 clusters and 32,000 plots. One quarter (ie. more than 800) of the clusters are permanent. In implementation NAFORMA measured a total of 30,773 plots out of which 25% are permanent for long-term monitoring. The remaining plots could not be accessed due to various reasons including remoteness, floods and bad terrain. Data were analyzed using locally available allometric functions and the literature. The total land area is 88,334,300 ha while the total growing stock is 3,322 million m3. NAFORMA biophysical results show that total forest area is estimated to be 48.1 million ha which is 54.4% of the total land area. The results are highly precise and as an example, the error estimate for forests and woodlands is below ten percent at 95% probability level indicating highly reliable volume estimates. The total Carbon in the living trees is 1,060.8 million tons. The major carbon sink is the woodland with 73.5% of the Tanzania mainland Carbon. TFS is committed to monitor her forests through re-measurements of the permanent sample plots established by NAFORMA. NAFORMA answers to the increasing need for forest resources data for national policy and international reporting addressing REDD and climate change as a whole.