title: Merging national forest and national forest health inventories to obtain an integrated forest resource inventory--experiences from Bavaria, Slovenia and Sweden.
abstract: To meet the demands of sustainable forest management and international commitments, European nations have designed a variety of forest-monitoring systems for specific needs. While the majority of countries are committed to independent, single-purpose inventorying, a minority of countries have merged their single-purpose forest inventory systems into integrated forest resource inventories. The statistical efficiencies of the Bavarian, Slovene and Swedish integrated forest resource inventory designs are investigated with the various statistical parameters of the variables of growing stock volume, shares of damaged trees, and deadwood volume. The parameters are derived by using the estimators for the given inventory designs. The required sample sizes are derived via the general formula for non-stratified independent samples and via statistical power analyses. The cost effectiveness of the designs is compared via two simple cost effectiveness ratios.
  
  
  RESULTS
  In terms of precision, the most illustrative parameters of the variables are relative standard errors; their values range between 1% and 3% if the variables' variations are low (s%<80%) and are higher in the case of higher variations. A comparison of the actual and required sample sizes shows that the actual sample sizes were deliberately set high to provide precise estimates for the majority of variables and strata. In turn, the successive inventories are statistically efficient, because they allow detecting the mean changes of variables with powers higher than 90%; the highest precision is attained for the changes of growing stock volume and the lowest for the changes of the shares of damaged trees. Two indicators of cost effectiveness also show that the time input spent for measuring one variable decreases with the complexity of inventories.
  
  
  CONCLUSIONS
  There is an increasing need for credible information on forest resources to be used for decision making and national and international policy making. Such information can be cost-efficiently provided through integrated forest resource inventories.
authors.affiliation: Department of Forest and Landscape Planning and Monitoring, Slovenian Forestry Institute, Večna pot 2, Ljubljana, Slovenia.
authors.forename: Marko
authors.initials: M
authors.lastname: Kovač
authors.affiliation: Department of Food, Agriculture and Forestry Cham - Division of Forestry, Bavarian State Ministry of Food, Agriculture and Forestry, Ölbergstraβe 3, Waldmünchen, Germany.
authors.forename: Arthur
authors.initials: A
authors.lastname: Bauer
authors.affiliation: Department of Forest Resource Management, Swedish University of Agricultural Sciences (SLU), Skogsmarksgränd, Umeå, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Ståhl
mesh_terms: D003247:Conservation of Natural Resources / Q000191:economics / Q000379:methods*; D003362:Cost-Benefit Analysis / Q000706:statistics & numerical data; D003657:Decision Making; D004784:Environmental Monitoring; D016468:Forestry / Q000191:economics / Q000706:statistics & numerical data*; D065928:Forests; D005858:Germany; D006801:Humans; D015233:Models, Statistical; D010935:Plant Diseases / Q000517:prevention & control / Q000706:statistics & numerical data; D018401:Sample Size; D017524:Slovenia; D013548:Sweden; D014197:Trees / Q000502:physiology