A Set of Biogeochemical Model Approaches for Integrated Modeling of Climate Change Impacts. Biospheric Carbon and Nitrogen Cycles

The biospheric research component of the Forestry and Climate Change Project has had as one of its objectives to develop a concept for a coupled carbon, nitrogen and water model which can be part of integrated models for analyses of climate change. This Working Paper describes a set of such model concepts. These models are now being tested and modified for implementation for regional analyses in the assessment phase of Siberian Forest Study

Dynamics of Fully Stocked Stands in the Territory of the Former Soviet Union

IIASA, the Russian Academy of Sciences, and Russian governmental organizations initiated the Siberian Forest Study in 1992, with the following objectives: Identification of possible future sustainable development options for the Siberian forest sector (assess the biosphere role of Siberian forests, and identify suitable strategies for sustainable development of forest resources, industry, infrastructure, and society); Identification of policies for various options to be implemented by Russian and international agencies. The first phase of the study built relevant and consistent databases for the upcoming analyses of the Siberian forest sector (Phase II). Nine cornerstone areas have been identified for the assessment analyses, namely, further development of the databases, greenhouse gas balances, forest resources and forest utilization, biodiversity and landscapes, non-wood functions, environmental status, forest industry and markets, transportation infrastructure, and socioeconomics. The existing increment estimations in the former USSR and Russia are limited to net increment calculations for periods between inventories which are aggregated for groups of species. Thus, the so called average increment as presented in the Forest State Account is an accumulative characteristic of the growing stock. The work in this paper presents a system developed to estimate the gross and net increment as well as the natural mortality for major forest species by ecoregion. In this report, the work dealing with evenaged fully stocked stands is presented. In the future, analyses for different stocking densities and different types of age structures will be carried out. This work on increment and mortality is a crucial step for the further analyses of the greenhouse gas balances, forest resources and forest utilization, and biodiversity and landscapes in cornerstones in phase 11