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        <r:String xml:lang="sv">Data för provträd från Riksskogstaxeringen</r:String>
        <r:String xml:lang="en">Sample tree data from the Swedish National Forest Inventory</r:String>
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          <r:String xml:lang="en">Swedish University of Agricultural Sciences</r:String>
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        <r:SimpleDate>2025-02-04</r:SimpleDate>
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      <r:Content xml:lang="sv">Datasetet innehåller en förteckning över provträd ≥10 cm DBH från Riksskogstaxeringen. Enskilda provträd som uppmätts och borrats inom en tio meter bred transekt under undersökningen 1923-1929 eller cirkulära provytor under undersökningarna 1953-1962, 1983-1992 och 2013-2022 ingår. Tröskelvärdet på 10 cm användes för att utesluta träd med mindre diameter som endast registrerades på delytor. Variablerna inkluderar bland annat kluster- och provyte-ID, trädslag, diameter, trädålder i brösthöjd och total trädålder, marktäckeklass samt expansionsfaktorer för uppskattning av antal träd och volymer. Den nuvarande riksskogstaxeringen bygger på ett årligt urval av cirka 20 000 cirkulära provytor, grupperade i kluster, varav cirka 12 000 inventeras i fält varje år. Data för ytterligare provträd samt fler variabler för enskilda provträd kan erhållas från Riksskogstaxeringen. För mer detaljerad information se: 

Jacobsson, Jonas, Fridman, Jonas, Axelsson, Anna-Lena, Milberg, Per (2025). An aging population? A century of change among Swedish forest trees. Forest Ecology and Management. 580:122509. https://doi.org/10.1016/j.foreco.2025.122509

Datafilen omfattar 17 kolumner och 384790 rader.</r:Content>
      <r:Content xml:lang="en">The data set include a list of sample trees  ≥10 cm DBH from the Swedish National Forest Inventory. Individual sample trees measured and cored within a ten metre wide transect during the 1923-1929 survey or circular sample plots during the 1953-1962, 1983-1992, and 2013-2022 surveys are included. The 10 cm threshold was used to exclude smaller diameter trees measured on small parts of sections or plots. Variables include cluster and plot ID, tree species, diameter, tree age at breast height and total tree age, land-cover class and expansion factors for estimation of number of trees and volumes. The current NFI is based on an annual sample of about 20,000 circular plots, grouped into clusters, of which about 12,000 are surveyed in the field each year. Data for additional sample trees and more variables for individual sample trees can be obtained from the Swedish National Forest Inventory. More details are presented in the article, see

Jacobsson, Jonas, Fridman, Jonas, Axelsson, Anna-Lena, Milberg, Per (2025). An aging population? A century of change among Swedish forest trees. Forest Ecology and Management. 580:122509. https://doi.org/10.1016/j.foreco.2025.122509

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          <r:Content xml:lang="en">Data from all tree covered areas in Sweden that have been inventoried by the Swedish National Forest Inventory. For more information about the division into regions, see the attached documentation and published article.</r:Content>
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