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The biodiversity (FE/C4)

Woody species composition [%].

NFI more detailed results are available here.

Geographical domain
Sorting criterion
Point estimate
The most probable value
Standard deviation
Point estimate standard deviation
Variation coef. %
Procentual expression of the standard deviation since the point estimation values
Sample size
Sample size
Min. sample size
Min. sample size
Interval estimation
Interval estimation

Table information

Topic: The biodiversity (FE/C4).
Indicator: Woody species composition.
Period: The NFI2 survey period, between 2011 and 2015.
Unit of measurement: Percent.
Population: Only living stems (incl. living windfalls) tall 10 cm and more (merchantable and non-merchantable wood stems) are considered within the total productive area.
Definition: This estimate of woody species composition is the proportion of the estimate of the productive forest area of a certain group of (considered) individuals and the estimate of the total productive forest area within the considered territory. The productive forest area includes forest stands, cleared boundary lines up to 4 m, unpaved roads up to and including 4 m traffic lane width, watercourses up to 4 m in channel width, seedbeds and clearcuts belonging to the forest land category according to the FAO FRA (Forest Resource Assessment) definition. Clearcuts and stand gaps are excluded from the total of the productive forest area, i.e. cases where no living merchantable or non-merchantable wood stem has been registered on the sample plot. Within the individual sample plots, the contribution to the estimate of a productive forest area is divided among the considered categories on the basis of their contribution to the estimate of the total production area. It is identified at the level of a stem with the area of its crown projection (to the horizontal plane), which is directly measured for the second-level samplers (mapping of crown projections of individual merchantable wood stems, measuring lengths of major and minor half-axes of ellipses approximating crown projections of individual non-merchantable wood stems). Regarding the other, registered, merchantable-wood stems and all the non-merchantable wood stems, the crown projection area was predicted by a dendrometric model using directly measured predictors – dbh (merchantable wood stems, a mixed model with a random effect of a sample plot level) or a stem height category (non-merchantable wood stems, a classical regression model with fixed effects). Second-level merchantable wood samplers were selected using a relascope method with a factor of 12 square metres per hectare. The samplers were selected among non-merchantable wood stems with an unchangeable probability of 0.21 (Bernoulli’s selection during registration within the non-merchantable registration circles). The purpose of the second-level samplers is to compensate for errors in the dendrometric model used. The principle of compensation is to estimate the total error of predictions (the concept of generalised local density, see Mandallaz 2007). A relatively small number of non-merchantable wood samplers (and even fewer second-level, non-merchantable wood samplers) led to instabilities in the estimation of woody species composition (within forest regeneration) in some geographical domains (regions) and for woody species groups with fewer stems. Due to uniform approach among different estimates of composition based on the production area (crown projection area), the second-level samplers and the two-phase procedure were used only for the merchantable wood stems.
Area: Accessible part of the productive forest area within the whole area of interest (geographical domain) excluding clearcuts and stand gaps. The forest land category corresponds with the definition of FAO FRA (Forest Resource Assessment).
Confidence interval: The confidence interval is constructed at a 95% confidence level (significance level alpha = 0.05).
Geographic domain type: Nomenclature of Territorial Units for Statistics, level 0 + 1 – state.; Nomenclature of Territorial Units for Statistics, level 3 – region.
Attribute domain: The group of conifers or broadleaves.

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