Individual tree models for the crown biomass distribution of Scots pine, Norway spruce and birch in Finland

This study examines the ability of high-density laser scanning to produce single-tree estimates in mixed stands of heterogeneous structure. Individual trees were detected from a constructed digital canopy height model by locating local maxima of the height values. The reference material comprised accurately measured field data for 10 mapped sample plots containing Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and different birches. To verify the accuracy of height measurements of single trees in more detail, the height of 29 Scots pine trees and their annual shoots of the last few years was carefully measured with a tacheometer and a glass fibre rod. The considered variables were the proportion of detected trees and tree height. As more than 80% of the dominant trees were detected, the results indicated that laser scanning can accurately describe the trees of the dominant tree layer. Because of the dense understorey tree layer in most of the sample plots, about 40% of all trees were detected. On the plot level, the stand structure affected the accuracy of the results considerably. The scanning-based tree height was most accurate for Norway spruce and least accurate for birches. The height of the separately measured 29 Scots pine trees was obtained with an accuracy of ±50 cm or better.

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Models for diameter and height growth of Scots pine, Norway spruce and pubescent birch in drained peatland sites in Finland

Silva Fennica ◽

10.14214/sf.10055 ◽

2018 ◽

Vol 52 (5) ◽

Cited By ~ 1

Author(s):

Jaakko Repola ◽

Hannu Hökkä ◽

Hannu Salminen

Keyword(s):

Norway Spruce ◽

Scots Pine ◽

Growth Models ◽

Mineral Soil ◽

Height Growth ◽

Growth Patterns ◽

Repeated Measurements ◽

Site Quality ◽

Individual Tree ◽

Tree Diameter

The aim of this study was to develop individual-tree diameter and height growth models for Scots pine, Norway spruce, and pubescent birch growing in drained peatlands in Finland. Trees growing in peatland sites have growth patterns that deviate from that of trees growing in mineral soil sites. Five-year growth was explained by tree diameter, different tree and stand level competition measures, management operations and site characteristics. The drainage status of the site was influencing growth directly or in interaction with other variables. Site quality had a direct impact but was also commonly related to current site drainage status (need for ditch maintenance). Recent thinning increased growth of all species and former PK fertilization increased growth of pine and birch. Temperature sum was a significant predictor in all models and altitude for spruce and birch. The data were a subsample of the 7th National Forest Inventory (NFI) sample plots representing northern and southern Finland and followed by repeated measurements for 15â20 yrs. Growth levels predicted by the models were calibrated using NFI11 data to remove bias originating from the sample of the modelling data. The mixed linear models technique was used in model estimation. The models will be incorporated into the MOTTI stand simulator to replace the current peatlands growth models.

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Comparing individual-tree growth models using principles of stand growth for Norway spruce, Scots pine, and European beech

Canadian Journal of Forest Research ◽

10.1139/cjfr-2014-0394 ◽

2015 ◽

Vol 45 (8) ◽

pp. 1006-1018 ◽

Cited By ~ 12

Author(s):

Sonja Vospernik ◽

Robert A. Monserud ◽

Hubert Sterba

Keyword(s):

Norway Spruce ◽

Scots Pine ◽

Tree Growth ◽

Growth Models ◽

Basal Area ◽

European Beech ◽

Growth And Yield ◽

Individual Tree ◽

Individual Tree Growth ◽

Volume Increment

We examined the relationship between thinning intensity and volume increment predicted by four commonly used individual-tree growth models in Central Europe (i.e., BWIN, Moses, Prognaus, and Silva). We replicated conditions of older growth and yield experiments by selecting 34 young, dense plots of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and European beech (Fagus sylvatica L.). At these plots, we simulated growth, with mortality only, to obtain the maximum basal area. Maximum basal area was then decreased by 5% or 10% steps using thinning from below. Maximum density varied considerably between simulators; it was mostly in a reasonable range but partly exceeded the maximum basal area observed by the Austrian National Forest Inventory or the self-thinning line. In almost all cases, simulated volume increment was highest at maximum basal area and then decreased with decreasing basal area. Critical basal area, at which 95% of maximum volume increment can be achieved, ranged from 0.46 to 0.96. For all simulators, critical basal area was lower for the more shade-tolerant species. It increased with age, except for Norway spruce, when simulated with the BWIN model. Age, where mean annual increment culminated, compared well with yield tables.

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Individual-tree basal area growth models for Scots pine, pubescent birch and Norway spruce on drained peatlands in Finland.

Silva Fennica ◽

10.14214/sf.a8517 ◽

1997 ◽

Vol 31 (2) ◽

Cited By ~ 23

Author(s):

Hannu Hökkä ◽

Virpi Alenius ◽

Timo Penttilä

Keyword(s):

Norway Spruce ◽

Scots Pine ◽

Growth Models ◽

Basal Area ◽

Individual Tree ◽

Basal Area Growth ◽

Area Growth

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Optimising the management of Scots pine (Pinus sylvestris L.) stands in Spain based on individual-tree models

Annals of Forest Science ◽

10.1051/forest:2003002 ◽

2003 ◽

Vol 60 (2) ◽

pp. 105-114 ◽

Cited By ~ 61

Author(s):

Marc Palah� ◽

Timo Pukkala

Keyword(s):

Pinus Sylvestris ◽

Scots Pine ◽

Individual Tree ◽

Tree Models

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Growth Responses of Boreal Scots Pine, Norway Spruce and Silver Birch Seedlings to Simulated Climate Warming over Three Growing Seasons in a Controlled Field Experiment

Forests ◽

10.3390/f11090943 ◽

2020 ◽

Vol 11 (9) ◽

pp. 943

Author(s):

Katri Nissinen ◽

Virpi Virjamo ◽

Antti Kilpeläinen ◽

Veli-Pekka Ikonen ◽

Laura Pikkarainen ◽

...

Keyword(s):

Norway Spruce ◽

Scots Pine ◽

Root Biomass ◽

Growing Season ◽

Silver Birch ◽

Shoot Biomass ◽

Growth Responses ◽

Growing Seasons ◽

Simulated Climate ◽

Shoot And Root Biomass

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.

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