Soderberg1986doublebark: Double bark for Individual trees in Sweden from Söderberg...

In Silviculturalist/forester: Forest Science and Forestry

Double bark for Individual trees in Sweden from Söderberg 1986.

Description

Applicable counties:

Northern Sweden
	Norrbottens lappmark
	Norrbottens kustland
	Västerbottens lappmark
	Västerbottens kustland
	Västernorrland - Ångermanlands landskap
	Västernorrland - Medelpads landskap
	Jämtland - Jämtlands landskap
	Jämtland - Härjedalens landskap
	Kopparberg - Sälen-Idre.
Central Sweden
	Kopparberg - övriga
	Gävleborg - Hälsinglands landskap
	Gävleborg - övriga
	Värmland
Southern Sweden
	Stockholm
	Uppsala
	Västmanland
	Södermanland
	Örebro
	Östergötland
	Skaraborg
	Älvsborg - Västergötlands landskap
	Älvsborg - Dalslands landskap
	Jönköping
	Kronoberg
	Kalmar
	Halland
	Kristianstad
	Malmöhus
	Blekinge
	Gotland

Regarding the regional division of the models:

Freely translated from Söderberg 1986 p. 29: 'The regional division is motivated in the following. For Pine the country has been divided into 3 regions (see figure 4.1), which are based on the different forms of Scots Pine which have been distinguished by Sylvén 1917. The distribution of the different forms of Scots Pine is assumed to depend on the expansion-history of the Pine, according to which the Pine immigrated both from the north and the south with a transitional zone in central Sweden, where both forms are present. For other species, the change in genotype is more continuous over the country (Kiellander 1974). For Norway Spruce, it is assumed that it has had time for 30-50 generations in northern Sweden, contrasted against only 10-20 in southern Sweden (Kiellander 1966). Therefore the same regional division is used for Norway Spruce as for Scots Pine. For the other species, the regional division is limited to two regions, wherein the northern and central regions have been merged.

NB in Söderberg (1986), no correction for logarithmic bias was introduced , as, (freely translated) p. 114: "At the presentation of the functions we lightly touched on the effects of the measurement errors in the variables which had been included in the regression. It was then concluded that several factors contrived to that the spread about the functions is overestimated. Therefore no correction for logarithmic bias was carried out, primarily because the effect of the errors in the indipendent variables on the spread about the function are difficult to establish. If one were to assume that the spread about the function was overestimated by 10 percent, the predicted growth from the functions would be increased by roughly 2 percent. For 20 percents overestimation, an increase of predicted growth by 4.5 percent."

Usage

Soderberg_1986_double_bark_central_Sweden_Pine(
  DBH.u.b.cm,
  age,
  latitude,
  altitude,
  soil_moisture,
  vegetation,
  continental,
  SI100
)

Soderberg_1986_double_bark_central_Sweden_Spruce(
  DBH.u.b.cm,
  age,
  soil_moisture,
  distance_to_coast_km,
  SI100
)

Soderberg_1986_double_bark_northern_central_Sweden_Birch(
  DBH.u.b.cm,
  age,
  latitude,
  vegetation,
  soil_moisture,
  SI100,
  distance_to_coast_km
)

Soderberg_1986_double_bark_northern_central_Sweden_Broadleaves(
  DBH.u.b.cm,
  age,
  latitude,
  altitude,
  distance_to_coast_km,
  SI100
)

Soderberg_1986_double_bark_northern_Sweden_Pine(
  DBH.u.b.cm,
  age,
  latitude,
  altitude,
  soil_moisture,
  distance_to_coast_km,
  vegetation,
  continental,
  SI100
)

Soderberg_1986_double_bark_northern_Sweden_Spruce(
  DBH.u.b.cm,
  age,
  latitude,
  soil_moisture,
  SI100
)

Soderberg_1986_double_bark_southern_Sweden_Birch(
  DBH.u.b.cm,
  age,
  latitude,
  altitude,
  vegetation,
  soil_moisture,
  SI100,
  distance_to_coast_km
)

Soderberg_1986_double_bark_southern_Sweden_Broadleaves(
  DBH.u.b.cm,
  age,
  latitude,
  altitude,
  soil_moisture,
  vegetation
)

Soderberg_1986_double_bark_central_Sweden_Pine(
  DBH.u.b.cm,
  age,
  latitude,
  altitude,
  soil_moisture,
  vegetation,
  continental,
  SI100
)

Soderberg_1986_double_bark_southern_Sweden_Spruce(
  DBH.u.b.cm,
  age,
  latitude,
  soil_moisture,
  SI100
)

Soderberg_1986_double_bark_Sweden_Beech(DBH.u.b.cm, age, latitude)

Soderberg_1986_double_bark_Sweden_Betula_pendula(
  DBH.u.b.cm,
  age,
  latitude,
  vegetation,
  soil_moisture,
  SI100,
  distance_to_coast_km
)

Soderberg_1986_double_bark_Sweden_Betula_pubescens(
  DBH.u.b.cm,
  age,
  latitude,
  vegetation,
  soil_moisture,
  SI100,
  distance_to_coast_km
)

Soderberg_1986_double_bark_Sweden_Oak(DBH.u.b.cm, age, latitude)

Arguments

DBH.u.b.cm	Diameter under bark of tree, in cm.
age	Age at breast height of the tree.
latitude	Latitude, degrees.
altitude	Altitude, metres.
soil_moisture	1-5. e.g. Sweden_soil_types()
vegetation	Vegetation type according to follows Swedish National forest inventory FALTSKIKT. e.g. Sweden_vegetation_types()
continental	TRUE, if the plot is situated in a continental climatic region. cf. Ångström 1958. e.g. Angstrom_1958_local_climate_Sweden(). Otherwise FALSE.
SI100	Site Index H100, m. TO DO: Ask P-M Ekö for clarification.
distance_to_coast_km	Closest distance to coast, in km, e.g. coast_distance()

Details

Oak

Multiple correlation coefficient R	0.89
Spread about the function sf	0.20
sf/Spread about the mean	0.38
Number of observations	315

Beech

Multiple correlation coefficient R	0.88
Spread about the function sf	0.21
sf/Spread about the mean	0.41
Number of observations	291

Norway Spruce For Norway Spruce, single function is reported area-wise due to use of dummy variables in only some locations. Regression statistics for entire country

Norway Spruce in Sweden

Multiple correlation coefficient R	0.84
Spread about the function sf	0.22
sf/Spread about the mean	0.48
Number of observations	12279

Scots Pine in Northern Sweden

Multiple correlation coefficient R	0.87
Spread about the function sf	0.22
sf/Spread about the mean	0.43
Number of observations	2316

Scots Pine in Central Sweden ##

Multiple correlation coefficient R	0.85
Spread about the function sf	0.23
sf/Spread about the mean	0.46
Number of observations	2014

Scots Pine in southern Sweden

Multiple correlation coefficient R	0.83
Spread about the function sf	0.24
sf/Spread about the mean	0.49
Number of observations	4833

Broadleaves in southern Sweden

Multiple correlation coefficient R	0.82
Spread about the function sf	0.30
sf/Spread about the mean	0.53
Number of observations	403

Broadleaves in Northern and Central Sweden

Multiple correlation coefficient R	0.84
Spread about the function sf	0.29
sf/Spread about the mean	0.52
Number of observations	244

*Birch species: Betula pendula

NB: Betula pendula is in the original source referred as Betula verrucosa

Multiple correlation coefficient R	0.83
Spread about the function sf	0.32
sf/Spread about the mean	0.47
Number of observations	846

*Birch species: Betula pubescens

Multiple correlation coefficient R	0.83
Spread about the function sf	0.23
sf/Spread about the mean	0.46
Number of observations	1852

Birch in Northern or Central Sweden

Multiple correlation coefficient R	0.85
Spread about the function sf	0.22
sf/Spread about the mean	0.43
Number of observations	1093

Birch in southern Sweden

Multiple correlation coefficient R	0.81
Spread about the function sf	0.27
sf/Spread about the mean	0.47
Number of observations	1605

Value

Double bark thickness, mm.

Source

Söderberg, U. (1986) Funktioner för skogliga produktionsprognoser - Tillväxt och formhöjd för enskilda träd av inhemska trädslag i Sverige. / Functions for forecasting of timber yields - Increment and form height for individual trees of native species in Sweden. Report 14. Section of Forest Mensuration and Management. Swedish University of Agricultural Sciences. Umeå. ISBN 91-576-2634-0. ISSN 0349-2133. pp.251.

Silviculturalist/forester documentation built on April 20, 2024, 2:13 p.m.