Forest models in Bulgaria : main developments and challenges WG1

1. COST ACTION FP0603: Forest models for research and decision support in sustainable forest management Forest models in Bulgaria: main developments and challenges WG1 Tatiana Stankova, Tzvetan Zlatanov, Ivailo Markoff, Toma Tonchev 1st Workshop and Management Committee Meeting.Institute of Silviculture, BOKU.8-9 of May 2008Vienna, Austria

2. Main features of Bulgarian forests • Forest cover (total/share): 3 651 243 ha/33% of the total area • Growing stock, annual growth and cuts: 590 396 884 m3, 7 055 885 m3 annual loggings (1.20% of the growing stock; • Main species: Pinus sylvestris, P. nigra, P. peuce, Picea abies, Abies alba, Fagus sylvatica, Populus sp., Quercus robur, Q. petrea, Q. frainetto, Q. cerris • Main non-wood products and services: • mushrooms, berries, medicinal herbs • soil protection, hunting, biodiversity, recreation • Main risks: • Effects of climate change (recurrent floodings, droughts, etc) • Changing of hydrological balance of lowland and riverside forest ecosystems due to establishment of irrigation constructions and hydroelectric power-stations • Destroying of mountainous forests through establishment of new tourist infrastructures • Forest fires • Illegal cuts. • Management and silvicultural characteristics: • Great diversity of pure and mixed forest types and forest sites • High value of non-timber services and products • Vast areas of erosion control plantations mainly from pine species • Significant areas of industrial plantations • Forest policy still in transition period

3. Forest modelling approaches and trends • Main types of models developed • Growth and yield tables for fully stocked stands and plantations of the main forest tree species; • Growth and yield tables for some poplar clones differentiated by initial densities; • Volume and assortment tables for individual trees and stands of the main forest tree species; • Aboveground biomass tables for Scots pine, Austrian black pine, White Fir and Norway spruce; • Stem form height tables and functions for the main forest tree species; • Stem volume functions for the main forest tree species; • Models of the height, diameter and stem form factor structure of the stands from the main types of forest tree species; • Stand Density Management (Control) Diagrams for Scots pine and Austrian black pine plantations; • Trends in modeling • The growth and yield tables currently used are classified by relative site index classes (anamorphic site index curves); • The growth and yield tables currently used are not diversified by densities or stocking rates; • Trends to model differentiation regarding: - The site indices: Polymorphic classification of the site index curves by stand growth mode and the respective growth and yield tables are developed for Scots pine, European beech, White Fir, Norway spruce and Macedonian pine natural stands and are currently being implemented in the forest inventory and management practices; - Initial densities: Growth and yield tables for poplar clones differentiated by initial densities;

4. Forest modelling approaches and trends • Recent research is concentrating in • Development of polymorphic classification of the site index curves by stand growth mode and the respective growth and yield tables for stands and plantations of other main forest tree species; • Biomass functions for short-term biomass production from intensively managed plantations; • Development of complex stand level models for growth and yield estimation and for planning and optimization of density and manegement activities - Stand Density Control (Management) Diagrams • Developing forest management information systems based on models

5. Simulators and information systems • Inventory - Inventory evaluation programmes after Schmidt-Haas - Lesotest - Programme for visualisation and validation of attribute and graphic data http://agrolesproject.com/cgi-bin/agro1?m=med6&zem2= • Stand level simulators - Volume predicting programmes (Proles, Agrolesporject) - Timber assortment predicting programmes (IG, Woodsort, Sort, WOODSELL 2000) (Woodsort: Dobrichov, Il. 1995. Volume and assortment modeling of trees and stand. PhD thesis, University of Forestry, Sofia.) (WOODSELL 2000 Vs. 3.0: Dobrichov, Il., R. Petrov, V. Valkov, D. Karamelski, M. Mateev, E. Evangelov. 2000. WOODSELL 2000 Vs. 3.0, BULWARK Ltd.) • Forest level decision support systems - Programme for monetary apraisal of forests (WB); - Programme for logging costs calculation (IG-Norm). - LesView – Programme for attribute forest data management http://agrolesproject.com/cgi-bin/agro1?m=med6&lv= - DitaView – Programme for the graphic forest data management http://agrolesproject.com/cgi-bin/agro1?m=med6&ditav= • Process based simulators

6. Data bases/archives on forest simulation models • Data base of logging (PR, System NUG); http://nug.bg/cgi-bin/index.cgi?Unit=Uses&act=New&type=2 • Data base of forest cultivation practices (GS); http://nug.bg/cgi-bin/index.cgi?Unit=Lkm&act=New • Virgin forests data base (GIS based):- Peter Veen and Ivan Raev (Ed.). 2006. Virgin forests in Bulgaria. Sofia (based on scientific report of the project PINMATRA/2002/011); • Data base “State of the forest ecosystems in Bulgaria” (MS Access based) under ICP "Forests“: Assessment and monitoring of air pollution effects on forests; • A National register of the seed production sources: seed stands, seed orchards, ortet collections, provenance test plantations and selected parental trees.

7. Research highlight Monitoring plots under ICP "Forests“:

8. Virgin forests in Bulgaria as a part of the WWF

9. Future challenges • Modeling risk from anthropogenic disturbances; • Modeling forest regeneration and succession (including after hazards); • Simulation models of coppice forests transformation processes; • Simulation models of coniferous plantations transformation processes; • Density optimization models for various management objectives; • Software development for the SDCDs for Scots pine and Austrian black pine plantations (Process based simulators); • Demonstrating the potential of models and simulators; • Economical models to optimize forest management; • Modeling open forest areas dynamics; • Modeling non-timber products and services management.

10. Innovative references • Douhovnikov, Y. 1965. Method of adapted scaling indices for stand structure and growth relationships determination for sustainable management. PhD thesis, Sofia, 219pp. (in Bulgarian) • Mihov, I., V. Marinkov. Precision and effectiveness of the combined method for forest stands taxation. Forestry (Sofia) 7, 1990; Forestry (Sofia) 1, 1991. (In Bulgarian) - Stankova, T. 2005. A density control model for Austrian black pine plantations in Bulgaria. Forest Science (Sofia) 3: 29-50. (In Bulgarian with English summary). • Panayotov, M. and Yurukov, S., 2005. Dendroecological analysis of the influence of strong winds and snow accumulation on the growth of trees at the treeline in Vitosha Mountain, Bulgaria. Proceedings of tree rings in Archaeology, Climatology and Ecology (TRACE 2005) Conference, 21-23d April 2005, Fribourg, Switzerland: 164-173. • Mihov. I., T. Tonchev. 2006. Growth model of a coppiced beech stand. International Scientific Conference “Management and sustainable development”. 25– 27 March 2007, Yundola, Bulgaria. (in Bulgarian)