INFLUENCE OF SUGAR MAPLE HEALTH ON FECUNDITY OF PEAR THRIPS IN MASSACHUSETTS

1992 ◽  
Vol 124 (6) ◽  
pp. 1129-1138 ◽  
Author(s):  
E. Carey ◽  
R.G. Van Driesche ◽  
J.S. Elkinton ◽  
T.S. Bellows ◽  
C. Burnham
Keyword(s):  
Adult Female ◽  
Sugar Maple ◽  
Causal Factor ◽  
Tree Health ◽  
Site Analysis ◽  
Sugar Maples ◽  
Root Starch ◽  
Individual Trees ◽  
Possible Cause

AbstractWidespread defoliation of sugar maple stands due to pear thrips, Taeniothrips inconsequens (Uzel), feeding occurred in Massachusetts in 1987 and 1988. To assess the role of tree health as a possible cause of these outbreaks, an experiment was conducted in sugar maple stands in Massachusetts in 1990. Sleeve cages were placed on mature sugar maples and stocked with adult female pear thrips to determine the relation between root starch reserves (an index of tree health) and thrips fecundity. The experiment was run at four sites, assessing both root starch levels and thrips fecundity on individual trees. Each stand showed a range from high to low starch values and trees at each end of the root starch index spectrum were selected for use in the experiment at each site. Analysis of data showed no differences between sites, apart from those linked to starch levels, and found thrips fecundity to be positively correlated with higher starch reserves. The results of this experiment do not support the original hypothesis that declining tree health was a causal factor in pear thrips outbreaks on sugar maple in Massachusetts.

scholarly journals Quantifying ice damage by counting branches on damaged sugar maple trees

2001 ◽  
Vol 77 (4) ◽  
pp. 637-642 ◽  
Author(s):  
R. A. Lautenschlager ◽  
John A. Winters
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Productive Capacity ◽  
Ice Storm ◽  
Third Order ◽  
Individual Tree ◽  
Statistical Confidence ◽  
Root Starch ◽  
Individual Trees ◽  
Foliar Biomass

We quantified the productive capacity of sugar maple crowns by counting branches (third order and epicormic) on damaged trees following the 1998 ice storm in southeastern Ontario. The covariates derived from branch counts provided greater statistical confidence, for explaining post-damage root starch and sap (volume and sweetness) production, than did crown damage estimates. When combined with predictive equations for leaf area and biomass per branch, branch counts produce estimates of foliar biomass for individual trees, regardless of the amount of damage received. Although visual estimates of crown damage seem appropriate for documenting stand-level injury, those interested in individual tree responses or comparing damage among trees should consider counting branches as a way to quantify the productive capacity of trees with or without damage. Key words: Acer saccharum, branch counts, damage assessment, foliar biomass, ice damage, sugar maple

Role of Armillaria calvescens and Glycobius speciosus in a sugar maple decline

1992 ◽  
Vol 22 (4) ◽  
pp. 549-552 ◽  
Author(s):  
Eric Bauce ◽  
Douglas C. Allen
Keyword(s):  
Electrical Resistance ◽  
Sugar Maple ◽  
Crown Condition ◽  
Regenerative Capacity ◽  
Early Stages ◽  
Sugar Maples ◽  
One Year ◽  
Crown Dieback ◽  
Apparently Healthy

Sugar maple, Acersaccharum Marsh., decline may be reversible during early stages before secondary insects and fungi invade stressed trees. Treatment with boric acid reduced the regenerative capacity of Armillariacalvescens Bérubé & Dessureault rhizomorphs and the percent infection of trembling aspen, Populustremuloides Michx., stakes used as a bioassay. One year after treatment, crown condition and cambial electrical resistance of trees initially in early stages of crown dieback improved compared with controls. The crown condition of sugar maples previously attacked by the sugar maple borer, Glycobiusspeciosus (Say), did not improve during 5 years of observation, whereas 18% of uninfested trees in similar initial crown condition did improve. Sugar maple borer was more abundant in declining trees [Formula: see text] than is typical of nondeclining infested trees [Formula: see text]. Declining trees had more sugar maple borer damage than apparently healthy trees (no evidence of crown dieback). The borer and the fungus are important contributing agents that prevent recovery of many declining sugar maples.

Blocked Lipid Exchange in Bilayers and its Possible Influence on the Shape of Vesicles

1974 ◽  
Vol 29 (9-10) ◽  
pp. 510-515 ◽  
Author(s):  
W Helfrich
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Spontaneous Curvature ◽  
Lipid Exchange ◽  
Lipid Distribution ◽  
Shape Transformations ◽  
Curvature Elasticity ◽  
Possible Cause

Abstract The role of lipid exchange in the curvature elasticity of bilayers is studied theoretically. Blocking of exchange between the monolayers may give rise to a nonequilibrium lipid distribution going hand in hand with a spontaneous curvature. Some possible consequences for vesicular deformations are discussed. Lipid nonequilibrium is tentatively suggest as one possible cause for certain shape transformations of red blood cells

scholarly journals Errors in Second/Foreign Language Learning and Their Interpretations

2017 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
Julia Falla Wood
Keyword(s):  
Language Learning ◽  
Second Language Learning ◽  
Mother Tongue ◽  
Meta Analysis ◽  
Cognitive Strategies ◽  
Reliability And Validity ◽  
Foreign Language Learning ◽  
Theoretical Foundations ◽  
Possible Cause

The aim of this article is to try to understand why the results of studies on errors in second language learning undertaken for several decades are diverse or even divergent. Some of these studies state that the mother tongue (L1) plays an important role in the learning process not only at the beginning, but also at higher levels of competency while others deny the influence of the mother tongue. The results of 60 studies on errors over a period of 40 years were contrasted to find out if a link existed between the theoretical foundations, and the interpretation of data, and conclusions of those studies. The results of the meta-analysis of studies whose theoretical foundations were related to operational cognitive strategies showed a continuum from partial to an important role of L1, and those related to order of acquisition, universal sequences showed a non-influence of L1. Another possible cause for this discrepancy was found in the method used to classify the errors. Finally, a possible cause could have been the methodological difficulties concerning the reliability and validity of the data. Only one third of the studies applied the control of bias and the triangulation of data.

scholarly journals Thrombocytopenia in septicemia: the role of disseminated intravascular coagulation

Blood ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 88-92 ◽  
Author(s):  
PB Neame ◽  
JG Kelton ◽  
IR Walker ◽  
IO Stewart ◽  
HL Nossel ◽  
...  
Keyword(s):  
Disseminated Intravascular Coagulation ◽  
Gel Chromatography ◽  
Severe Thrombocytopenia ◽  
Intravascular Coagulation ◽  
Platelet Counts ◽  
Normal Platelet ◽  
Platelet Survival ◽  
Possible Cause

Abstract The mechanism of isolated thrombocytopenia in septicemia is unknown, but compensated disseminated intravascular coagulation (DIC) has been suggested as a possible cause. To investigate this possibility, platelet counts and sensitive assays for in vivo thrombin and plasmin generation, including fibrinogen gel chromatography and fibrinopeptide A (FPA) assays, were obtained on 31 septicemic patients. Fifteen of 17 patients with gram-negative septicemia and 8 of 14 patients with gram- positive septicemia had thrombocytopenia. Platelet survival studied demonstrated a decreased platelet survival. In 11 of 12 patients with severe thrombocytopenia (platelet count less than 50,000mul), there was laboratory evidence of intravascular coagulation. In contrast, there was little evidence of intravascular coagulation in 8 of 11 patients with moderate thrombocytopenia (platelet counts 50,000 to less than 150,000/mul) or in 7 of 8 patients with normal platelet counts. This report indicates that while DIC accompanies thrombocytopenia in many patients with severe thrombocytopenia, there is frequently little evidence for intravascular coagulation in patients with moderate thrombocytopenia. It is apparent that factors other than intravascular thrombin must play a role in producing the thrombocytopenia of septicemia.

scholarly journals Expected Rates of Value Growth for Individual Sugar Maple Crop Trees in the Great Lakes Region: A Comment

2009 ◽  
Vol 26 (4) ◽  
pp. 141-144 ◽  
Author(s):  
John E. Wagner
Keyword(s):  
Great Lakes ◽  
Discount Rate ◽  
Sugar Maple ◽  
Net Present Value ◽  
Great Lakes Region ◽  
Internal Rate Of Return ◽  
The Interest Rate ◽  
Silvicultural System ◽  
Individual Trees ◽  
Value Growth

Abstract Webster et al. (Webster et al. 2009. Expected rates of value growth for individual sugar maple crop trees in the Great Lakes region. North. J. Appl. For. 26:133‐140) discuss updated recommendations for marking individualsugar maple trees in the Great Lakes region within a selection silvicultural system based in part on current market information. They calculate the annual rate of value growth (RVG) of individual trees for a single 10-year period using an internal rate of return (IRR) formula. It is the authors'misinterpretation of the IRR and RVG as an interest or discount rate similar to that used in a net present value calculation that is the focus of this comment. The interest rate includes information not contained in the IRR and is used to estimate whether an investment (e.g., marking decisionsfor sugar maple trees) will increase (or decrease) an individual's wealth. The distinction between what the IRR or RVG describes and the interest or discount rate is critical for determining the economic and financial implications of management decisions.

Comment on “Long-term decline of sugar maple following forest harvest, Hubbard Brook Experimental Forest, New Hampshire”

2019 ◽  
Vol 49 (7) ◽  
pp. 861-862
Author(s):  
Scott W. Bailey ◽  
Robert P. Long ◽  
Stephen B. Horsley
Keyword(s):  
New England ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Management Practices ◽  
Hubbard Brook Experimental Forest ◽  
Data Set ◽  
Hubbard Brook ◽  
Whole Tree

Cleavitt et al. (2018, Can. J. For. Res. 48(1): 23–31, doi: 10.1139/cjfr-2017-0233 ) report a lack of sugar maple (Acer saccharum Marsh.) regeneration in Hubbard Brook Experimental Forest (HBEF), Watershed 5 (W5), following whole-tree clearcut harvesting and purport that harvesting-induced soil calcium depletion contributed to regeneration failure of this species. In New England, clearcutting is a silvicultural strategy used to promote less tolerant species, especially birch (Betula spp.; Marquis (1969), Birch Symposium Proceedings, USDA Forest Service; Leak et al. (2014), doi: 10.2737/NRS-GTR-132 ), which is just the outcome that the authors report. While this study reports an impressive, long-term data set, given broad interest in sugar maple and sustainability of forest management practices, we feel that it is critical to more fully explore the role of nutrition on sugar maple dynamics, both prior to and during the experiment, and to more fully review the scientific record on the role of whole-tree clearcutting in nutrient-induced sugar maple dynamics.

Espèces biologiques d'armillaire dans les érablières dépérissantes du sud-est du Québec

1990 ◽  
Vol 20 (1) ◽  
pp. 43-47 ◽  
Author(s):  
M. Sabourin ◽  
M. Dessureault ◽  
J. A. Bérubé
Keyword(s):  
Sugar Maple ◽  
Biological Species ◽  
Frequent Species ◽  
Almost All ◽  
Armillaria Species

Biological species of the Armillaria complex present in declining sugar maple stands in southeastern Quebec were identified by pairing monosporous isolates with known tester strains. Armillariaostoyae (I), A. gemina (II), A. calvescens (III), and A. sinapina (V) were collected. Armillariacalvescens was the most frequent species and was found in almost all the stands sampled. The presence of various Armillaria species was not correlated with either the severity of decline of the stands or the health of the hosts with which they were associated, suggesting that none of the species present in sugar maple stands is particularly responsible for their decline. However, the role of A. calvescens and the factors that favor its development warrant further investigations because this species appears to be found almost exclusively on maple trees.

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