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See detailAssessing deadwood using harmonized National Forest Inventory data
Rondeux, Jacques ULg; Bertini, Roberta; Bastrup-Birk, Annemarie et al

in Forest Science (2012), 58(3), 269-283

Deadwood plays an important role in forest ecological processes and is fundamental for the maintenance of biological diversity. Further, it is a forest carbon pool whose assessment must be reported for ... [more ▼]

Deadwood plays an important role in forest ecological processes and is fundamental for the maintenance of biological diversity. Further, it is a forest carbon pool whose assessment must be reported for international agreements dealing with protection and forest management sustainability. Despite wide agreement on deadwood monitoring by national forest inventories (NFIs), much work is still necessary to clarify definitions so that estimates can be directly compared or aggregated for international reporting. There is an urgent need for an international consensus on definitions and agreement on harmonization methods. The study addresses two main objectives : to analyze the feasibility of harmonization procedures for deadwood estimates and to evaluate the impact of the harmonization process based on different definitions on final deadwood estimates. Results are reported for an experimental harmonization test using NFI deadwood data from 9,208 sample plots measured in nine European countries and the United States. Harmonization methods were investigated for volume by spatial position (lying or standing), decay classes, and woody species accompanied by accuracy assessments. Estimates of mean plot volume based on harmonized definitions with minimum length/height of 1 m and minimum diameter thresholds of 10, 12, and 20 cm were on average 3, 8, and 30% smaller, respectively, than estimates based on national definitions. Volumedifferences were less when estimated for various deadwood categories. An accuracy assessment demonstrated that, on average, the harmonization procedures did not substantially alter deadwood observations (root mean square error 23.17%). [less ▲]

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See detailBridging national and reference definitions for harmonizing forest statistics
Stahl, Göran; Cienciala, Emil; Chirici, Gherardo et al

in Forest Science (2012), 58(3), 214-223

Harmonization is the process of making information and estimates comparable across administrative borders. The degree to which harmonization succeeds depends on many factors, including the conciseness of ... [more ▼]

Harmonization is the process of making information and estimates comparable across administrative borders. The degree to which harmonization succeeds depends on many factors, including the conciseness of the definitions, the availability and quality of data, and the methods used toconvert an estimate according to a local definition to an estimate according to the reference definition. Harmonization requires the availability and use of common reference definitions and methods for converting from estimates based on national definitions to estimates based on reference definitions. This article focuses on conversion methods, which are characterized as « bridges » because they can be seen as a means of crossing from islands of local definitions to the mainland of a reference definition. A structured approach is proposed for constructing bridges of three kinds : reductive, neutral, and expansive bridges. A hierarchical decision tree is presented to guide users and to summarize the propositions and case examples with different types of bridges to illustrate the concepts. Although the article addresses harmonization of forest information, the results are relevant for harmonizing a broad variety of area statistics. [less ▲]

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See detailEstimating dead wood during national forest inventories: a review of inventory methodologies and suggestions for harmonization
Woodall, Christopher W.; Rondeux, Jacques ULg; Verkerk, Pieter J. et al

in Environmental Management (2009), 44(4), 624-631

Efforts to assess forest ecosystem carbon stocks, biodiversity, and fire hazards have spurred the need for comprehensive assessments of forest ecosystem dead wood (DW) components around the world ... [more ▼]

Efforts to assess forest ecosystem carbon stocks, biodiversity, and fire hazards have spurred the need for comprehensive assessments of forest ecosystem dead wood (DW) components around the world. Currently, information regarding the prevalence, status, and methods of DW inventories occurring in the world’s forested landscapes is scattered. The goal of this study is to describe the status, DW components measured, sample methods employed, and DW component thresholds used by national forest inventories that currently inventory DW around the world. Study results indicate that most countries do not inventory forest DW. Globally, we estimate that about 13% of countries inventory DW using a diversity of sample methods and DW component definitions. A common feature among DW inventories was that most countries had only just begun DW inventories and employ very low sample intensities. There are major hurdles to harmonizing national forest inventories of DW: differences in population definitions, lack of clarity on sample protocols/estimation procedures, and sparse availability of inventory data/reports. Increasing database/ estimation flexibility, developing common dimensional thresholds of DW components, publishing inventory procedures/protocols, releasing inventiory data/reports to international peer review, and increasing communication (e.g.,workshops) among countries inventorying DW are suggestions forwarded by this study to increase DW inventory harmonization. [less ▲]

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