Local competition in a naturally established jack pine stand

1989 ◽  
Vol 67 (9) ◽  
pp. 2630-2635 ◽  
Author(s):  
N. C. Kenkel ◽  
J. A. Hoskins ◽  
W. D. Hoskins
Keyword(s):  
Spatial Pattern ◽  
Jack Pine ◽  
Differential Mortality ◽  
Time Interval ◽  
Local Competition ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Dead Trees ◽  
Standing Dead ◽  
The Mean

The spatial pattern of 1375 jack pine individuals (459 live, 257 standing dead, and 659 stumps) in a pure, even-aged, naturally established stand was mapped. Three maps corresponding to different stages of stand development were recognized: live + dead (initial pattern, n = 1375), live (following self-thinning, n = 459), and live + standing dead (survivors plus most recent mortality, n = 716). The Dirichlet-Thiessen tessellations of these maps indicated that the distribution of tile areas (area potentially available) becomes increasingly equitable over time. A significant positive correlation between diameter at breast height of surviving trees and their area potentially available was found for each map; this correlation was highest for the live tessellation. In the live + dead and live + standing dead tessellations, the mean tile area of dead trees was significandy smaller than that of survivors. The spatial pattern of diameter at breast height values of survivors revealed a positive autocorrelation: larger trees tend to have large neighbours and smaller trees have small ones. These results suggest a model of differential mortality in which the smaller individuals in a stand, particularly those surrounded by larger individuals, are most likely to die over a given time interval.

Cone serotiny in jack pine: ontogenetic, positional, and environmental effects

1993 ◽  
Vol 23 (3) ◽  
pp. 394-401 ◽  
Author(s):  
Sylvie Gauthier ◽  
Yves Bergeron ◽  
Jean-Pierre Simon
Keyword(s):  
Boreal Forest ◽  
Life Span ◽  
Environmental Effects ◽  
Thermal Environment ◽  
Jack Pine ◽  
Time Interval ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Pine Trees ◽  
Environmental Causes

The main objective of this study was to determine empirically if the absence of serotinous (seed retaining) cones in young jack pine (Pinusbanksiana Lamb.) was due to environmental causes, particularly to ground-radiated heat, or to the juvenility of the trees. Twenty-five jack pine populations were sampled in the southern part of the boreal forest, in Abitibi, Quebec. The age, diameter at breast height (DBH), and number of serotinous and nonserotinous cones per branch were determined for 30 trees per population. A subset of 10 other trees per population was felled to determine the number of serotinous and nonserotinous cones per cone age-class and per branch. DBH, age, and height of these trees were also measured. The results showed that DBH is more strongly related than age or height to the appearance of the first serotinous cone. Most trees that did not bear any serotinous cones had not reached a DBH of 7 cm. Until individuals had reached a DBH of 10 cm, the proportion of serotinous cones increased from year to year. The proportion of serotinous cones ≥4 years old was significantly lower than that of younger cones, indicating that old cones tended to open, particularly on those trees with a DBH greater than 10 cm. The proportion of serotinous cones on branches below 260 cm was significantly lower than that of cones situated above that height. The same trends were observed for cones where serotiny was determined in the laboratory, suggesting that the thermal environment is not entirely responsible for serotinous cone opening. We suggest that the age of branches affects the opening of cones and that the absence of serotinous cones in small trees is related to their juvenility. Seed release resulting from the absence of serotiny in small jack pine trees and the opening observed in old cones may play an important role in serotinous populations when the time interval between two fires is longer than the life-span of one jack pine generation.

Biomass of jack pine and mixed hardwood stands in northeastern New Brunswick

1976 ◽  
Vol 6 (4) ◽  
pp. 441-447 ◽  
Author(s):  
David A. MacLean ◽  
Ross W. Wein
Keyword(s):  
New Brunswick ◽  
Tree Species ◽  
Biomass Accumulation ◽  
Jack Pine ◽  
Tree Crown ◽  
Tree Diameter ◽  
Stem Biomass ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Fire Origin

Biomass accumulation in 12 jack pine and 11 mixed hardwood stands of fire origin ranging in age from 7 to 57 years is presented. Logarithmic equations relating aboveground tree, crown, and stem biomass to tree diameter at breast height are given for eight tree species.

Biogenic Imprint on Hillslopes in the Sudety Mts. — Origin and Consequences of the Tree Uprooting Process

2014 ◽  
Vol 48 (1) ◽  
Author(s):  
Łukasz Pawlik
Keyword(s):  
National Park ◽  
Qualitative Description ◽  
Main Subject ◽  
Diameter At Breast Height ◽  
Geomorphological Mapping ◽  
Breast Height ◽  
The World ◽  
The Mean ◽  
Tree Uprooting ◽  
Root Plate

AbstractThe main subject of this article is the tree uprooting process and its effects on forested hillslopes in the Sudety Mts. The research has been carried out between 2010 and 2012 in the Karkonosze National Park (KNP), Stołowe Mountains National Park (SMNP) and Suche Mts. The methods included: detailed geomorphological mapping and measurements of root plates of recently fallen trees and relict treethrow mounds and pits (called pit-and-mound microtopography), their qualitative description and measurements of diameter at breast height (dbh) of uprooted tree trunks.The mean root plate volume was 0.3-1.4 mIt has been shown that tree uprooting can contribute to the evolution of regolith and soils and it is an important factor of their disturbances. This reflects results from other sites in the World. However, in the Sudety Mts. the significance of tree uprooting has been validated only locally and it is suggested that its importance decreases proportionally to the area under consideration. Here, biogenic transport is limited to treethrow pits on gentle hillslopes but can be much more effective at steeper sites.

Effect of minimum diameter at breast height and standing dead wood field measurements on the accuracy of ALS-based forest inventory

2015 ◽  
Vol 45 (10) ◽  
pp. 1280-1288 ◽  
Author(s):  
Juha Keränen ◽  
Jussi Peuhkurinen ◽  
Petteri Packalen ◽  
Matti Maltamo
Keyword(s):  
Forest Inventory ◽  
Laser Scanning ◽  
Dead Wood ◽  
Minimum Diameter ◽  
Living Tree ◽  
Breast Height ◽  
Dead Trees ◽  
Standing Dead ◽  
Standing Dead Trees ◽  
Young Forests

Where airborne laser scanning (ALS) measures the entire aboveground vegetation, the target of a stand-level forest inventory is usually the living tree stock above a given diameter but excluding standing dead trees. The aim here was to investigate the effects of varying field-measured minimum diameters (3–10 cm) and standing dead wood on ALS-based forest inventories. The characteristics considered in this case were volume, basal area, number of stems, mean diameter, and mean height for each species, as well as the total growing stock and the total aboveground biomass. The field data comprised measurements of all trees that were ≥3 cm at breast height (1.3 m) on 601 sample plots located in pine-dominated managed forests in eastern Finland. The results showed that the minimum diameter had a significant effect on the estimates obtained in young forests, for which the three smallest minimum diameter datasets (3, 4, and 5 cm) gave the most accurate estimates. Minimum diameter had no marked influence in the case of middle-aged or mature forests. The inclusion of standing dead trees did not have any effect on the estimates of living tree characteristics. The effect of minimum diameter is minor where large-area inventory applications are concerned; however, especially from a silvicultural point of a view, a minimum diameter of 3 cm should be employed in young forests, for which a large proportion of the tree stock usually consists of small trees, i.e., with diameters of <5 cm.

Modeling relative error in stem basal area estimates

1990 ◽  
Vol 20 (5) ◽  
pp. 496-502 ◽  
Author(s):  
T. G. Gregoire ◽  
S. M. Zedaker ◽  
N. S. Nicholas
Keyword(s):  
Basal Area ◽  
Field Measurements ◽  
Mean Square ◽  
Interval Estimates ◽  
Tree Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
The Mean ◽  
The Difference ◽  
Relative Errors

The computed estimate of basal area was the focus of this investigation into the accuracy of tree diameter measurements. Diameter at breast height was measured on 101 trees, the breast height disc was removed from the stem, and each disc outline was then digitized to determine its actual area. Actual areas were compared with the basal areas computed with the field measurements of diameter by expressing the deviations as a proportion of the actual areas. These relative errors averaged 3.1% when basal area was computed with a taped diameter at breast height, and they averaged −2.5% when the mean of two calipered, perpendicular diameter at breast height measurements were used. Noncircularity accounted for about 2.6% of the bias, on average, in basal areas from taped diameters. Root mean square error of relative basal area errors ranged from 7.3 to 7.9% among these methods. The difference between basal areas computed with a taped diameter at breast height and with calipered diameter at breast height was computed and expressed as a proportion of the actual basal area. On average, a difference of 5% was observed. Interval estimates for these differences are presented.

Development of blue stain in mechanically harvested Scots pine (Pinus sylvestris) logs during storage

2020 ◽  
Vol 50 (1) ◽  
pp. 42-50
Author(s):  
Grzegorz Szewczyk ◽  
Robert Jankowiak ◽  
Bartosz Mitka ◽  
Piotr Bożek ◽  
Piotr Bilański ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Age Class ◽  
Duration Of Storage ◽  
Blue Stain ◽  
Microclimatic Conditions ◽  
The Mean ◽  
The Aesthetic

Blue stain is a type of discoloration that considerably lowers the aesthetic qualities of wood. During harvesting, fungal inoculum finds its way into the wood through places of cutting, delimbing, and damage to the tree stem. The development of peripheral blue stain in the logs of Scots pine (Pinus sylvestris L.) due to damage by a harvester head was investigated, using logs felled and delimbed with a chainsaw as reference. The development of blue stain was related to the age class of the stand, the date of felling, and the microclimatic conditions of the wood storage place. The mean surface area of blue stain in logs produced with the harvester was almost 35 cm2, approximately 30% larger than that of the reference logs. In stands of the fourth age class (diameter at breast height 32 cm), the surface of blue stain was more than two times larger than that of stands of the third age class (diameter at breast height 24 cm). The mean area of blue stain in wood stored after spring felling (19.3 cm2) was about 50% of that after summer felling (38.2 cm2). In particular, the development of blue stain in logs obtained with a harvester was visible between weeks 6 and 9 after spring felling and between weeks 3 and 6 after summer felling. For both felling dates, the range of blue stain depended less on air temperature around the wood stack and depended more on the duration of storage.

Patterns of balsam fir mortality caused by an uncontrolled spruce budworm outbreak

1989 ◽  
Vol 19 (9) ◽  
pp. 1087-1095 ◽  
Author(s):  
David A. MacLean ◽  
Donald P. Ostaff
Keyword(s):  
Tree Mortality ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Regression Equations ◽  
Cape Breton Island ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Cape Breton ◽  
Dead Trees ◽  
Site Characteristics

Tree mortality caused by spruce budworm (Choristoneurafumiferana (Clem.)) defoliation was assessed annually from 1976 to 1985 in 20 mature balsam fir (Abiesbalsamea (L.) Mill.) stands on Cape Breton Island, Nova Scotia, and was related to defoliation and to tree, stand, and site characteristics. Ten to 12 years after the start of the budworm outbreak, fir mortality averaged 87% of the merchantable volume (range 60–100%) among the stands. Timing of mortality was similar to that found in studies of previous outbreaks. In the first 4 years of the outbreak, virtually all the trees that died had more than 90% cumulative defoliation but, overall, 64, 21, and 14% of the dead trees had cumulative defoliation >90, 76 to 90, and 51 to 75%, respectively. Early in the outbreak, fir mortality was generally negatively correlated with tree vigor, relative crown position, or diameter at breast height, but in later years, trees were killed irrespective of these factors. Fir mortality was evenly distributed among different sized trees, and 73 to 86% of the trees in each 5 cm diameter at breast height class died. A linear regression equation between dead fir volume and total fir volume explained 89% of the variability in mortality among stands. Percent fir mortality was correlated (r = 0.84) with visual estimates of cumulative defoliation (including all age-classes of foliage) in 1981, but mortality was not correlated with cumulative current annual defoliation or with site characteristics. Using regression equations, fir mortality during this budworm outbreak was predicted to within ±6 m2/ha in 14 of 18 (78%) of the stands, with a relative accuracy of 17.7%.

scholarly journals Snags and Down Wood in Missouri Old-Growth and Mature Second-Growth Forests

1997 ◽  
Vol 14 (4) ◽  
pp. 165-172 ◽  
Author(s):  
Stephen R. Shifley ◽  
Brian L. Brookshire ◽  
David R. Larsen ◽  
Laura A. Herbeck
Keyword(s):  
Size Distribution ◽  
Basal Area ◽  
Wildlife Habitat ◽  
Old Growth ◽  
Frequency Distributions ◽  
Dead Trees ◽  
Second Growth ◽  
Standing Dead ◽  
The Mean ◽  
Negative Exponential

Abstract As forest managers in the Midwest focus more attention toward understanding and maintaining ecosystem processes, greater emphasis is being placed on the role of snags and down wood in providing wildlife habitat, cycling nutrients, and maintaining continuity in forest structure following harvest. We measured five remnant old-growth hardwood tracts and six mature, second-growth, hardwood tracts in Missouri and compared findings concerning (1) the volume of down wood and (2) the number and size distribution of snags (i.e., standing dead trees). Volume of down wood ≥ 10 cm in diameter averaged 36 m³/ha on the old-growth tracts, double the 18 m³/ha mean volume for the second-growth sites. This difference in volume was concentrated in pieces of down wood with diameters larger than 20 cm; below diameters of 20 cm the number of pieces of down wood by diameter class was similar for the old-growth and second-growth sites. On the old-growth sites, the mean basal area of snags ≥ 10 cm dbh was 1.9 m²/ha. This was approximately 1.5 times greater than the mean basal area of snags on the second-growth sites. The number of snags ≥ 10 cm dbh on the old growth sites was approximately 9% pf the number of live trees on those sites. The corresponding value for second-growth sites was 8%. On both the old-growth and second-growth sites, the number of snags and the number of live trees by dbh class followed a negative exponential (reverse-J) form. Frequency distributions for the number of snags by dbh class closely followed those for live trees on the same sites. These results provide managers with general guidelines for the quantity of down wood likely to be found in mature second-growth forests and old-growth forests. We also provide some provisional rules of thumb for estimating the density and size distribution of snags from values observed for live trees in the same stand. North. J. Appl. For. 14(4):165-172.

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