STUDIES OF DECAY IN RELATION TO TREE SPECIES, AGE, AND SITE AND THEIR APPLICATION IN FOREST INVENTORIES AND ESTABLISHMENT OF PRIORITY CUTTING SCHEDULES IN BRITISH COLUMBIA

1956 ◽  
Vol 32 (1) ◽  
pp. 53-57 ◽  
Author(s):  
J. E. Browne
Keyword(s):  
British Columbia ◽  
Tree Species ◽  
Forest Inventories

Forest reproduction methods for coastal British Columbia: Principles, criteria, and a stand selection guide

1994 ◽  
Vol 70 (5) ◽  
pp. 569-577 ◽  
Author(s):  
K. Klinka ◽  
G. J. Kayahara ◽  
R. E. Carter
Keyword(s):  
British Columbia ◽  
Tree Species ◽  
Stand Structure ◽  
Species Selection ◽  
Cutting Method ◽  
Management Objectives ◽  
Dichotomous Key ◽  
Management Factors ◽  
Reproduction Method ◽  
Coastal British Columbia

Once a decision to regenerate a particular stand is made at the forest level, a forester has to make critical decisions at the stand level as to the choice of cutting method for existing stands to regenerate the desired species and develop a stand of the desired structure. Two related critical decisions in stand-level forest management are (1) selecting the best tree species to regenerate on a given site, and (2) selecting the appropriate method of cutting existing stands for both the regeneration of the desired species within a certain time and for maintaining or developing the desired stand structure. This paper discusses the management factors and principles and criteria for choosing a cutting method to meet decision (2) (i.e., the reproduction method). The four criteria used to guide the appropriate reproduction method are (1) maximum sustainable forest productivity, (2) stand reliability, (3) silvicultural feasibility, and (4) harvesting feasibility. With these criteria in mind, a stand-level guide devised for coastal British Columbia is proposed. This guide is in the form of a dichotomous key and is based on 13 selected ecological, stand, and management factors. Combining this approach with principles, criteria and guidelines for tree species selection already practiced, regeneration and management objectives can be achieved both on a species-and site-specific basis. Key words: forest reproduction methods, decision support systems, silvicultural prescriptions, harvesting methods, stand regeneration, stand structure

scholarly journals An Individual-Tree Mortality Model for Complex Stands of Southeastern British Columbia

2005 ◽  
Vol 20 (2) ◽  
pp. 101-109 ◽  
Author(s):  
Hailemariam Temesgen ◽  
Stephen J. Mitchell
Keyword(s):  
British Columbia ◽  
Tree Species ◽  
Tree Mortality ◽  
Model Development ◽  
Mortality Rates ◽  
Average Deviation ◽  
Individual Tree ◽  
Permanent Sample Plots ◽  
Diameter Increment ◽  
Mortality Model

Abstract An individual-tree mortality model was developed for major tree species in complex stands (multi-cohort, multiaged, and mixed species) of southeastern British Columbia (BC), Canada. Data for 29,773 trees were obtained from permanent sample plots established in BC. Average annual diameter increment and mortality rates ranged from 0.08 to 0.17 cm/year and from 0.3 to 2.6%, respectively. Approximately 70% of the trees were used for model development and 30% for model evaluation. After evaluating the model, all 29,773 trees were used to fit the final model. A generalized logistic model was used to relate mortality to tree size, competition, and relative position of trees in a stand. The evaluation test demonstrated that the model appears to be well behaved and robust for the tree species considered in this study. For the eight tree species, the average deviation between observed and predicted annual mortality rates varied from −0.5 to 0.7% in the test data. West. J. Appl. For. 20(2):101–109.

Estimating Breast Height Diameters from Stump Measurements in British Columbia

1982 ◽  
Vol 58 (3) ◽  
pp. 143-145 ◽  
Author(s):  
Julien P. Demaerschalk ◽  
Stephen A. Y. Omule
Keyword(s):  
British Columbia ◽  
Prediction Model ◽  
Tree Species ◽  
Prediction System ◽  
Tree Diameter ◽  
Local Volume ◽  
Breast Height ◽  
Central Canada ◽  
Volume Equation ◽  
Stump Diameter

A means of estimating tree diameter at breast height from stump measurements has many applications. In this paper, metric equations are derived for estimating diameters at breast height from measured stump heights for all commercial tree species in British Columbia by age class and biogeoclimatic zones. The model found best was the same one as used by Alemdag and Honer (1977) for eleven tree species from eastern and central Canada. This prediction system can be incorporated into any local volume equation to derive a tree volume prediction model based on stump diameter and stump height.

scholarly journals A Deep Fusion uNet for Mapping Forests at Tree Species Levels with Multi-Temporal High Spatial Resolution Satellite Imagery

2021 ◽  
Vol 13 (18) ◽  
pp. 3613
Author(s):  
Ying Guo ◽  
Zengyuan Li ◽  
Erxue Chen ◽  
Xu Zhang ◽  
Lei Zhao ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Tree Species ◽  
High Spatial Resolution ◽  
Forest Type ◽  
Species Level ◽  
Forest Inventories ◽  
Forest Classification ◽  
Plantation Species ◽  
Multi Temporal ◽  
Artificial Intelligence Technology

It is critical to acquire the information of forest type at the tree species level due to its strong links with various quantitative and qualitative indicators in forest inventories. The efficiency of deep-learning classification models for high spatial resolution (HSR) remote sensing image has been demonstrated with the ongoing development of artificial intelligence technology. However, due to limited statistical separability and complicated circumstances, completely automatic and highly accurate forest type mapping at the tree species level remains a challenge. To deal with the problem, a novel deep fusion uNet model was developed to improve the performance of forest classification refined at the dominant tree species level by combining the beneficial phenological characteristics of the multi-temporal imagery and the powerful features of the deep uNet model. The proposed model was built on a two-branch deep fusion architecture with the deep Res-uNet model functioning as its backbone. Quantitative assessments of China’s Gaofen-2 (GF-2) HSR satellite data revealed that the suggested model delivered a competitive performance in the Wangyedian forest farm, with an overall classification accuracy (OA) of 93.30% and a Kappa coefficient of 0.9229. The studies also yielded good results in the mapping of plantation species such as the Chinese pine and the Larix principis.

Potentials for Controlling Bark Percentage of the Commercial Tree Species of British Columbia

1981 ◽  
Vol 57 (4) ◽  
pp. 156-161 ◽  
Author(s):  
J. Harry G. Smith ◽  
A. Kozak
Keyword(s):  
British Columbia ◽  
Tree Species ◽  
Statistical Significance ◽  
Tree Improvement ◽  
Bark Thickness ◽  
Guide Tree ◽  
Breast Height ◽  
Improvement Programs ◽  
Standard Deviations

Diameters inside and outside bark from 13 sections were used to define variation in bark percentages for 33 844 trees representing 28 major groups of the commercial tree species of British Columbia. The range of age, height, dbh, and dbh/height associated with each group was determined. Statistical significance of effects of these factors and of up to 12 inventory zones was determined for double bark thickness as a percentage of dbh. Bole bark volumes were compared with wood volumes for trees exceeding two standard deviations of bark percentage at breast height. Thick barked trees were more common and a few have equal portions of wood and bark. Our description of the characteristics of the trees with least or most bark should help guide tree improvement programs. Identification of the extent to which stand factors can influence average bark characteristics may help timber managers grow trees of desired bark proportions.

Effects of suppression and release on sapling growth for 11 tree species of northern, interior British Columbia

2000 ◽  
Vol 30 (10) ◽  
pp. 1571-1580 ◽  
Author(s):  
Elaine F Wright ◽  
Charles D Canham ◽  
K D Coates
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Tree Species ◽  
Light Level ◽  
Long Term Effects ◽  
Partial Cutting ◽  
Tolerant Species ◽  
Shade Tolerant Species ◽  
Sapling Growth ◽  
Over Time

Saplings of canopy tree species frequently undergo alternating periods of suppression and release before reaching canopy size. In this study, we document the effects of periods of suppression and release on current responses to variation in light by saplings of the 11 major tree species of northwestern, interior British Columbia. We were specifically interested in the degree to which increasing length of suppression had long-term effects on subsequent response to release in gaps or following partial cutting, and the degree to which the effects of suppression were ameliorated with time following release. At least some saplings of all 11 species had undergone alternating periods of suppression and release. The most shade-tolerant species generally did not show either a decline in growth over time during suppression or a gradual increase in growth at a given light level over time during release. The least shade-tolerant species exhibited significant declines in growth rate during suppression; however, in all of the species except trembling aspen (Populus tremuloides Michx.), the effects of suppression disappeared over time during release. Failure to account for the effects of past suppression and release leads to significant overestimates of the initial responses of shade-intolerant species to release. Our results suggest that competitive balances between species shift substantially over time as a result of growth history and that these shifts have significant effects on successional patterns.

The influence of overstorey Populus on epiphytic lichens in subboreal spruce forests of British Columbia

2010 ◽  
Vol 40 (1) ◽  
pp. 143-154 ◽  
Author(s):  
Jocelyn Campbell ◽  
Gary E. Bradfield ◽  
Cindy E. Prescott ◽  
Arthur L. Fredeen
Keyword(s):  
British Columbia ◽  
Tree Species ◽  
Forest Site ◽  
East Central ◽  
Lichen Community ◽  
Unknown Factor ◽  
Calcium Phosphorus ◽  
Manganese Availability ◽  
Different Levels ◽  
Site Types

The composition and abundance of lichen communities on conifer saplings beneath five overstorey tree species were compared at three subboreal forest site types in east-central British Columbia. Site-level differences in lichen communities were attributed to different levels of moisture and light limitations in the understorey. At sites with adequate moisture and light, cyanolichens were uniformly abundant and species rich on conifer saplings beneath different understorey species. However, at sites with moisture or light limitations, cyanolichens were more abundant and species rich on conifer saplings beneath overstorey Populus than on saplings beneath other overstorey tree species. Cyanolichen communities also showed greater species richness on conifer saplings beneath the Populus canopy than on the trunk of Populus itself. Differences in calcium, phosphorus, molybdenum, and manganese availability in throughfall precipitation failed to explain much of the variation in lichen community structure. These results suggest that Populus can facilitate cyanolichens under sub optimal moisture or light conditions by providing some, as yet unknown, factor that is critical to their establishment and growth.

scholarly journals Regression models of volume increment percentage in the Most represented stands of coniferous tree species in Serbia

2002 ◽  
pp. 25-35 ◽  
Author(s):  
Stanisa Bankovic ◽  
Milan Medarevic ◽  
Damjan Pantic
Keyword(s):  
Scots Pine ◽  
Tree Species ◽  
Forest Inventory ◽  
Regression Models ◽  
Diameter Increment ◽  
Forest Inventories ◽  
Volume Increment ◽  
Large Scope ◽  
Coniferous Tree Species

Considering the great significance of volume increment in forestry, it is understandable that there are numerous methods of its assessment. However, all these methods have some disadvantages, either the accuracy of the obtained results, too large scope of works of forest inventory (economicity), or the restriction only to stands of certain silvicultural type. To make the method of stand volume increment more economic and simplified, we defined regression models for volume increment percentage assessment in fir, spruce, Austrian pine and Scots pine stands in Serbia. Empirical data were fitted by four regression models for each tree species. The criteria for the final selection of models for the determination of volume increment percentage were the relevant statistic parameters of regression and correlation analysis, and the degree of concordance of "real" and fitted ("table") values of volume increment percentage. The selected models for the above tree species are Fir Spruce Austrian pine Scots pine In the practical work of the assessment of current volume increment in the stand, in regular forest inventories, the method of volume increment percentage should be implemented with correction factors for the fitting of "table" (obtained by this method) values of volume increment and "real" values (obtained by the method of diameter increment), on at least 10 % of the stands of the same or similar stand class (same or similar tree species and stand form). In this way, the costs of forest inventory would be reduced, and the obtained results would range within the limits of the required accuracy .

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