PM_BA: Basal area growth functions for even-aged monocultures or...

In Silviculturalist/forester: Forest Science and Forestry

Basal area growth functions for even-aged monocultures or mixed stands in Sweden.

Description

Pine, northern Sweden Number of observations: 3461

Thinning	SI<160	160≤SI<200	SI≥200
Unthinned	920	1014	523
Thinned	319	441	244

Multiple correlation coefficient: 0.91

Standard deviation about the function, Sf : 0.411

Sf/ Standard deviation about the mean, (%): 41

Pine, central Sweden Number of observations: 1631

Thinning	SI<180	180≤SI<220	SI≥220
Unthinned	309	296	391
Thinned	150	186	299

Multiple correlation coefficient: 0.92

Standard deviation about the function, Sf : 0.376

Sf/ Standard deviation about the mean, (%): 39

Pine, southern Sweden Number of observations: 1631

Thinning	SI<160	160≤SI<200	200≤SI<240	SI≥240
Unthinned	223	461	835	1114
Thinned	84	244	523	656

Multiple correlation coefficient: 0.92

Standard deviation about the function, Sf : 0.409

Sf/ Standard deviation about the mean, (%): 40

Norway Spruce, northern Sweden

Number of observations: 3959

Thinning	SI<160	160≤SI<200	SI<200
Unthinned	1405	1012	431
Thinned	476	455	180

Multiple correlation coefficient: 0.94

Standard deviation about the function, Sf : 0.391

Sf/ Standard deviation about the mean, (%): 36

Norway Spruce, central Sweden

Number of observations: 1773

Thinning	SI<180	180≤SI<220	220≤SI<260	SI≥260
Unthinned	212	291	322	270
Thinned	102	169	235	172

Multiple correlation coefficient: 0.93

Standard deviation about the function, Sf : 0.427

Sf/ Standard deviation about the mean, (%): 39

Norway Spruce, southern Sweden

Number of observations: 4864

Thinning	SI<220	220≤SI<260	260≤SI<300	SI≥300
Unthinned	333	643	1121	1031
Thinned	163	404	685	484

Multiple correlation coefficient: 0.93

Standard deviation about the function, Sf : 0.433

Sf/ Standard deviation about the mean, (%): 48

Birch, northern and central Sweden

Number of observations: 4429

Thinning	SI<140	140≤SI<180	180≤SI<220	SI>220
Unthinned	859	1157	792	482
Thinned	243	378	269	249

Multiple correlation coefficient: 0.87

Standard deviation about the function, Sf : 0.607

Sf/ Standard deviation about the mean, (%): 50

Birch, southern Sweden

Number of observations: 3072

Thinning	SI<220	220≤SI<260	260≤SI<300	SI>300
Unthinned	249	406	772	756
Thinned	89	181	334	285

Multiple correlation coefficient: 0.88

Standard deviation about the function, Sf : 0.599

Sf/ Standard deviation about the mean, (%): 48

Broadleaves, northern and central Sweden Number of observations: 1367

Thinning	SI<160	160≤SI<200	200≤SI<240	SI>240
Unthinned	319	335	225	160
Thinned	85	100	75	68

Multiple correlation coefficient: 0.89

Standard deviation about the function, Sf : 0.608

Sf/ Standard deviation about the mean, (%): 47

Broadleaves, southern Sweden

Number of observations: 1404

Thinning	SI<240	240≤SI<280	280≤SI<320	SI>320
Unthinned	131	209	424	266
Thinned	60	75	151	88

Multiple correlation coefficient: 0.90

Standard deviation about the function, Sf : 0.622

Sf/ Standard deviation about the mean, (%): 45

Beech Number of observations: 298

Thinning	SI<310	SI≥310
Unthinned	67	103
Thinned	61	67

Multiple correlation coefficient: 0.89

Standard deviation about the function, Sf : 0.603

Sf/ Standard deviation about the mean, (%): 46

Oak Number of observations: 678

Thinning	SI<280	280≤SI<320	SI>320
Unthinned	117	185	165
Thinned	54	93	64

Multiple correlation coefficient: 0.89

Standard deviation about the function, Sf : 0.603

Sf/ Standard deviation about the mean, (%): 46

Usage

Eko_PM_1985_basal_area_5_year_increment_northern_Sweden_Pine(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  ba_quotient_chronic_mortality,
  ba_quotient_acute_mortality
)

Eko_PM_1985_basal_area_5_year_increment_central_Sweden_Pine(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  ba_quotient_chronic_mortality,
  ba_quotient_acute_mortality
)

Eko_PM_1985_basal_area_5_year_increment_southern_Sweden_Pine(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_chronic_mortality,
  ba_quotient_acute_mortality
)

Eko_PM_1985_basal_area_5_year_increment_northern_Sweden_Spruce(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_chronic_mortality = 0,
  ba_quotient_acute_mortality = 0
)

Eko_PM_1985_basal_area_5_year_increment_central_Sweden_Spruce(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_chronic_mortality,
  ba_quotient_acute_mortality
)

Eko_PM_1985_basal_area_5_year_increment_southern_Sweden_Spruce(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_chronic_mortality,
  ba_quotient_acute_mortality
)

Eko_PM_1985_basal_area_5_year_increment_northern_central_Sweden_Birch(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_chronic_mortality,
  ba_quotient_acute_mortality
)

Eko_PM_1985_basal_area_5_year_increment_southern_Sweden_Birch(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_chronic_mortality,
  ba_quotient_acute_mortality
)

Eko_PM_1985_basal_area_5_year_increment_northern_central_Sweden_Broadleaves(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_chronic_mortality
)

Eko_PM_1985_basal_area_5_year_increment_southern_Sweden_Broadleaves(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_chronic_mortality,
  ba_quotient_acute_mortality
)

Eko_PM_1985_basal_area_5_year_increment_Sweden_Beech(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_acute_mortality
)

Eko_PM_1985_basal_area_5_year_increment_Sweden_Oak(
  basal_area.m2,
  stem_number_ha,
  age_at_breast_height,
  basal_area_other_species,
  SI,
  basal_area_weighted_mean_diameter,
  basal_area_weighted_mean_diameter_other_species,
  thinned,
  thinned_previous_5_years,
  vegetation,
  south_sweden,
  soil_moisture,
  altitude,
  TAX77 = 0,
  fertilised,
  latitude,
  ba_quotient_acute_mortality
)

Arguments

basal_area.m2	Basal area over bark (m2/ha)
stem_number_ha	Number of stems per hectare.
age_at_breast_height	Age at breast height, calculated as the mean age of the two thickest trees (years).
basal_area_other_species	Basal area of other species on the plot. (m2/ha)
SI	Site index H100 Pine , m.
basal_area_weighted_mean_diameter	Diameter corresponding to mean basal area (m).
basal_area_weighted_mean_diameter_other_species	Diameter coressponding to mean basal area (m) of other species on plot.
thinned	1 if the stand been thinned, otherwise 0.
thinned_previous_5_years	1 if the stand has been thinned within 5 years, otherwise 0.
vegetation	Variable indicating vegetation type scaled from -5 to +4 as follows: Field Layer Code (NFI) Description Index 1 Tall herbs w/o dwarf shrubs 4 2 Tall herbs with bilberry 2.5 3 Tall herbs with cowberry 2 4 Low herbs w/o dwarf shrubs 3 5 Low herbs with bilberry 2.5 6 Low herbs with cowberry 2 7 No field layer 3 8 broad-leafed grasses 2.5 9 narrow-leaved grasses 1.5 10 Sedge, tall -3 11 Sedge, low -3 12 Horsetail 1 13 Bilberry 0 14 Cowberry -0.5 15 Crowberry -3 16 Poor shrub -5 17 Lichen-rich -0.5 18 Lichen-dominated -1
south_sweden	1 if the plot is situated in southern Sweden.
soil_moisture	Type 1="Dry/torr",2="Mesic/frisk",3="Mesic-moist/frisk-fuktig",4="Moist/fuktig",5="Wet/Blöt"
altitude	Metres above sea level
TAX77	Always 0 for simulation. Otherwise see original text.
ba_quotient_chronic_mortality	Quotient of basal area (total?) expected to die during the next five-year period, from e.g. crowding, drought (factors that have affected the growth of the stand)
ba_quotient_acute_mortality	Quotient of basal area (total?) expected to die during the next five-year period, from e.g. wind or snowbreak, which do not affect the growth.
fertilised	1 if the stand has been fertilised, otherwise 0.
latitude	Latitude, degrees.

Value

Basal area growth over bark during the five year growth period.

Source

Ekö, Per Magnus (1985) "En produktionsmodell för skog i Sverige, baserad på bestånd från riksskogstaxeringens provytor: A growth simulator for Swedish forests, based on data from the national forest survey. Rapporter nr. 16. Swedish University of Agricultural Sciences, dept. of Silviculture. Umeå. ISBN 91-576-2386-4. ISSN 0348-8969. p. 63.

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