Estimating aboveground woody biomass of forests in Poland for FAO/ECE and UNFCCC reporting

Abstract

Abstract. The United Nations Framework Convention on Climate Change and the Kyoto Protocol have committed member states to reduce greenhouse gas emissions by, among others, promoting the increase of carbon sequestration by carbon sinks (including woody biomass in forests). In order to achieve these objectives, an international reporting system was designed.The stock of woody biomass depends on several environmental and managerial factors, which determine species composition and age structure of a forest as well as characteristics of individual trees. Estimating aboveground woody biomass, especially on a nation-wide level, is generally based on the application of conversion factors to known characteristics such as the volume of the growing stock. The application of default conversion factors, as proposed by international guidelines, however, is questionable, since inventory systems for and definitions of growing stock differ from country to country.In this paper, the methods used in Poland to estimate woody biomass for the FAO and the UNFCC reporting, were presented and analysed. We also analysed the influence of some stand and tree characteristics, such as tree species composition and content of bark and its density, on the stock of woody biomass. We conclude that issues not addressed in the IPCC guidelines, such as big differences in wood and bark density, especially for pine, need to be taken into consideration when making estimations. Moreover, the results of this paper show that biomass conversion and expansion factors (BCEF) proposed by IPCC are not adequate for Polish conditions.

Site Index Models for Main Forest-Forming Tree Species in Poland

“…Most likely, the differences in growth curves obtained using dynamic site index modeling and yield tables, the latter obtained using data older than 100 years, were due to the changes in growth conditions over this time. As shown by the latest research, these were changes mainly in nitrogen deposition and the climatic parameters [31,84], as well as an increase in carbon dioxide concentration [85]. Changing site conditions over time [31] undoubtedly constitutes a disadvantage of the site index concept [3], as they lead to a negative correlation between stand age and the site index [21,60,69].…”

Consequences of different sample drying temperatures for accuracy of biomass inventories in forest ecosystems

“…For F. sylvatica we also used height ranging from 10 to 30 m, as models were based on both DBH and height. For calculations we assumed that bark comprised 15% of stem biomass, similarly as Jabłoński and Budniak 39 in country-level biomass assessment, as some of models provided only stem biomass.…”

“…Country-level stem wood and bark biomass published by Jabłoński and Budniak39 , biomass recalculated using D coefficients(Table 3)and differences in biomass. All values in10 6 Mg.…”