scholarly journals The occurrence of flowering and fruiting on individual trees over 3 years and their effects on subsequent crown condition

Trees ◽  
1994 ◽  
Vol 8 (3) ◽  
pp. 139-150 ◽  
Author(s):  
John L. Innes
Keyword(s):  
Crown Condition ◽  
Individual Trees

The relationship between electrical resistance and severity of decline symptoms in Acersaccharum

1977 ◽  
Vol 7 (3) ◽  
pp. 469-475 ◽  
Author(s):  
Dennis Newbanks ◽  
Terry A. Tattar
Keyword(s):  
Electrical Resistance ◽  
Callus Tissue ◽  
Measurement Techniques ◽  
Crown Condition ◽  
Increment Core ◽  
Sugar Maples ◽  
Time Of Year ◽  
Urban Campus ◽  
Individual Trees ◽  
The Relationship

Electrical resistance (ER) measurements of the xylem–cambium area were affected by time of year, air temperature, tree diameter, species, bark blemishes, callus tissue, decay, and measurement techniques. Our results indicate that in urban sugar maples there was no statistically significant correlation between ER and tree response to physiologic stress, as measured by visual crown classification (based on the severity of decline symptoms) and by increment core data. Trees in a non-urban, campus setting showed a significant correlation between electrical resistance and visual crown symptoms (r = 0.61). Trees with intermediate crown-condition ratings had the highest average ER, and on the basis of ER, individual trees could not be placed into stress-response categories because of large variations in ER within each crown-condition class. No significant correlation was found between ER and applied physiologic stresses in nursery-grown sugar maples.

Influence of Insect Herbivory on the Decline of Black Box (Eucalyptus largiflorens)

1995 ◽  
Vol 43 (6) ◽  
pp. 555 ◽  
Author(s):  
C Stone ◽  
PE Bacon
Keyword(s):  
Leaf Shape ◽  
Insect Herbivory ◽  
Visual Assessment ◽  
Black Box ◽  
Crown Condition ◽  
Mature Trees ◽  
Trunk Diameter ◽  
Diameter Increment ◽  
Southern Central ◽  
Individual Trees

The contribution of insect herbivory to the canopy decline of Eucalyptus largiflorens F.Muell. (black box) was assessed on nine irrigated properties around Deniliquin in southern central New South Wales. Fully expanded leaves less than 1 year old were sampled from 36 mature trees in June 1993 and again in June 1994 after half the trees had been treated with a systemic insecticide in November 1993. Insect herbivory in treated trees fell significantly from 27 to 9%. It also fell, but to a lesser extent (28-19%, P < 0.05), in the untreated trees. The fall in insect herbivory in control trees corresponded to a decrease in rainfall in 1994 when the rainfall was 50% of that for 1993. There was a significant linear relationship between insect herbivory and trunk diameter increment in the untreated trees. There was no consistent relationship between insect herbivory and the visual assessment of crown condition. Although E. largiflorens is described as having both narrow adult and juvenile foliage, adjacent trees in this study differed significantly in their leaf length:breadth ratios. Canopies with a dominance of broader foliage had significantly higher levels of herbivory. Individual trees tended to replace foliage with leaves of similar morphology. It is suggested that this variation in leaf shape may be genetic rather than environmental. If so, landholders could select for trees with narrower foliage which may result in reduced impact of insect herbivory.

Predicting tree survival in Ontario sugar maple (Acer saccharum) forests based on crown condition

2008 ◽  
Vol 38 (7) ◽  
pp. 1730-1741 ◽  
Author(s):  
Koji Tominaga ◽  
Shaun A. Watmough ◽  
Julian Aherne
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Survival Models ◽  
Crown Condition ◽  
Index Data ◽  
South Central ◽  
Tree Survival ◽  
Short Term Mortality ◽  
Consecutive Time ◽  
Individual Trees

Decline index (indicator of crown condition) data from 102 forest plots (approximately 10 000 trees) during 1986–2004 were compiled to derive survival models for south-central Ontario, Canada. The dominant species was sugar maple ( Acer saccharum Marsh.) with approximately 75% occurrence (n = 7640). The predictor variables for sugar maple survivorship included the decline index of 1 or 2 years prior to the beginning of the modelled period and ecological region (Algoma, Georgian Bay, Huron–Ontario, and Upper St. Lawrence). The observed crown condition of sugar maple improved significantly over the study period; in contrast, short-term mortality rate did not improve. The risk of sugar maple mortality could be predicted from decline index data for a single year indicating that the risk of tree death increases with higher decline index values (declining crown condition). Moreover, using 2 years of decline index data indicated that the risk of tree death also increased with the length of consecutive time individual trees have higher decline index values. Trees in the Algoma region, which represent the northern limit of sugar maple distribution in Ontario, were significantly more likely to die than trees in Huron–Ontario region.

Resistance of some plum cultivars and individual trees to Plum Pox (Sharka) virus

Agronomie ◽  
1981 ◽  
Vol 1 (8) ◽  
pp. 617-622 ◽  
Author(s):  
D. ŠUTI ◽  
M. RANKOVIĆ
Keyword(s):  
Individual Trees ◽  
Sharka Virus

Descriptive statistics of tree crown condition in California, Oregon, and Washington

2010 ◽  
Author(s):  
KaDonna C. Randolph ◽  
Sally J. Campbell ◽  
Glenn Christensen
Keyword(s):  
Descriptive Statistics ◽  
Tree Crown ◽  
Crown Condition

Mit Initialfemeln zum Plenterwald (Essay) | The creation of selection forest using initial femel cut (essay)

2009 ◽  
Vol 160 (6) ◽  
pp. 137-143
Author(s):  
Rudi Kynast
Keyword(s):  
Mixed Forest ◽  
Point Of View ◽  
Age Group ◽  
Black Forest ◽  
Crown Height ◽  
Short Intervals ◽  
Total Growth ◽  
Cost Calculations ◽  
Selection Forest ◽  
Individual Trees

Although selection forests have clear advantages over age-group forests in view of their total growth performance, their net product and their stability, not to mention the sustainability of their beneficial effect, the proportion of this type of forest is insignificantly small in Germany and also in mixed forest in the mountains. It is therefore all the more surprising that scarcely any discernable efforts have been made to increase the proportion of selection forests. For a conversion, an alternative model for the treatment of the stands is adopted, whereby it is no longer the encouragement of the growth to maturity of individual trees in the stand which is aimed for, but rather the transformation of the whole stand to a selection forest using available stand elements and elements created by an early initiation of regeneration. Based on his experience in the forestry district of Kirchzarten in the Black Forest, Germany, the author describes the procedure for a successful conversion. This is to be started as soon as possible, that is to say when the crown height of the trees is about 18 metres and with corresponding usable dimensions, using small group shelter-wood cuts, a so-called initial femel cut. To get the conversion started it is advisable to remove whole groups of predominantly badly situated and overgrown trees. The stand will be additionally structured later through further interventions at short intervals. In the process, here and there really well situated trees will actually be left to stand solitar y, in other places w hol e self-cont aine d groups will b e created and else where valuabl e mixed s tand elements will be selected for permanent preservation, this in order to create a situation in which there are about 35 overstorey trees per hectare. On the basis of his own cost calculations, the author comes to the conclusion that the conversion is, from a financial point of view, superior compared with the age-group forest in that it brings higher proceeds more quickly and more often.

Update on the Boundaries of the Curly Birch Range

2020 ◽  
pp. 9-21
Author(s):  
L.V. Vetchinnikova ◽  
◽  
A.F. Titov ◽  
◽  
Keyword(s):  
Population Size ◽  
Natural Populations ◽  
Forest Tree ◽  
Published Data ◽  
Population Approach ◽  
Key Factors ◽  
History Of ◽  
Individual Trees ◽  
Karelian Birch

The article reports on the application of the best known principles for mapping natural populations of curly (Karelian) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti – one of the most appealing representatives of the forest tree flora. Relying on the synthesis and analysis of the published data amassed over nearly 100 years and the data from own full-scale studies done in the past few decades almost throughout the area where curly birch has grown naturally, it is concluded that its range outlined in the middle of the 20th century and since then hardly revised is outdated. The key factors and reasons necessitating its revision are specified. Herewith it is suggested that the range is delineated using the population approach, and the key element will be the critical population size below which the population is no longer viable in the long term. This approach implies that the boundaries of the taxon range depend on the boundaries of local populations (rather than the locations of individual trees or small clumps of trees), the size of which should not be lower than the critical value, which is supposed to be around 100–500 trees for curly birch. A schematic map of the curly birch range delineated using this approach is provided. We specially address the problem of determining the minimum population size to secure genetic diversity maintenance. The advantages of the population approach to delineating the distribution range of curly birch with regard to its biological features are highlighted. The authors argue that it enables a more accurate delineation of the range; shows the natural evolutionary history of the taxon (although it is not yet officially recognized as a species) and its range; can be relatively easily updated (e.g. depending on the scope of reintroduction); should be taken into account when working on the strategy of conservation and other actions designed to maintain and regenerate this unique representative of the forest tree flora.

Guides for Estimating Forest Stand Losses to Gypsy Moth

1984 ◽  
Vol 1 (2) ◽  
pp. 21-23 ◽  
Author(s):  
David A. Gansner ◽  
Owen W. Herrick
Keyword(s):  
Species Composition ◽  
Gypsy Moth ◽  
Tree Mortality ◽  
Cost Effective ◽  
Forest Stand ◽  
Measure Data ◽  
Effective Management ◽  
Field Plot ◽  
Crown Condition ◽  
As Species

Abstract People who have to make decisions about cost-effective management for gypsy moth need help in predicting and evaluating its effects. Field plot data collected during recent outbreaks in Pennsylvania are being used to develop guides for predicting forest stand losses to the pest Presented here are some of the more useful products of that effort to date. Easy-to-measure data for forest characteristics such as species composition and crown condition can be collected and applied in models that estimate potential stand and tree mortality and changes in timber value. North. J. Appl. For. 2:21-23, June 1984.

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