Effects of beech bark disease on the growth of American beech (Fagusgrandifolia)

1993 ◽  
Vol 23 (8) ◽  
pp. 1566-1575 ◽  
Author(s):  
David G. Gavin ◽  
David R. Peart

We studied radial growth reduction in American beech (Fagusgrandifolia Ehrh.) in relation to the level of defect induced by beech bark disease, in second-growth and old-growth northern hardwoods stands in New Hampshire. In the second-growth stand at Moose Mountain (n = 243 trees), 1989–1990 radial growth declined significantly with increasing severity of external symptoms. The severity of external symptoms increased significantly with DBH. To examine temporal trends, internal defect induced by the disease was quantified as the percentage of growth sheath cankered in each year, by cross-sectioning a subsample of 40 trees. Internal defect first appeared in 1950, increased through 1969, then declined until a major pulse of infection in the period 1983–1987. Sectioned trees were divided into infection classes based on a cumulative measure of internal defect. Growth of severely infected trees first fell below that of uninfected trees in 1965, and was consistently lower after 1972. The growth ratio of severely infected to uninfected trees generally declined from 1960 to 1990; by 1990, growth of severely infected trees was reduced by more than 40% relative to healthy trees. This decline in the growth ratio corresponded well to the increase in cumulative internal defect in the stand, suggesting that disease stress had cumulative effects on tree vigor. The relation between beech bark disease and growth was also examined on an individual-tree basis; recent growth decline was significantly greater for trees with higher levels of internal defect. Internal defect was a better predictor of growth trends than was external defect. External defect was only moderately correlated with internal defect (r2 = 0.503). In the old-growth stand at Bartlett, N.H. (n = 40 trees) infection was quantified from external symptoms only. As in the second-growth stand, the growth of severely infected trees in the old-growth stand fell significantly below that of uninfected trees. However, significant differences in growth between uninfected and severely infected trees occurred earlier in the old-growth stand, first appearing in 1949. Delayed growth reductions in the second-growth stand may be associated with changes in shade and moisture affecting the beech scale, changes in tree physiological stress after selective logging, or changes in the density of large trees. Beech may survive long periods of infection by beech bark disease. However, our results demonstrate clearly that beech bark disease has reduced the growth of American beech in both second-growth and old-growth northern hardwoods stands for several decades.

2015 ◽  
Author(s):  
Karin S. Fassnacht ◽  
Dustin R. Bronson ◽  
Brian J. Palik ◽  
Anthony W. D'Amato ◽  
Craig Lorimer ◽  
...  

1988 ◽  
Vol 18 (1) ◽  
pp. 38-42 ◽  
Author(s):  
David R. Houston ◽  
Harry T. Valentine

In North America, beech bark disease occurs when bark of American beech (Fagusgrandifolia) is infested by beech scale (Cryptococcusfagisuga), then infected and killed by a fungus, Nectriacoccinea var. faginata, Nectriagalligena, or both. In long-affected stands, internal defect results as trees are cankered over time. The amount of defect, patterns of defect development, and the relationship of climate to these patterns were studied in 50 trees from two stands in eastern Maine. Two cross sections from each of five 1 m long bolts from each tree were selected at random by importance sampling. The total area of canker on the outside surface of each growth sheath of each bolt was estimated from the arc lengths of cankers on the annual rings of the sampled cross sections. Cankering began in stems 12–37 years old and 2–11 cm diameter. Rates of cankering increased over time; years of high or low cankering were synchronous between trees and stands. Cankering in year N + 1 was negatively correlated (R2 = 0.803) with October rainfall in year N and number of severely cold days from December in year N–1 through March in year N. Presumably, these factors adversely affect the survival and establishment of the beech scale and perhaps the development of and infection by Nectria spp. Mild winters and dry autumns since 1983 may have permitted the marked increases in beech scale and bark cankering observed in study plots throughout the range of beech bark disease.


2003 ◽  
Vol 33 (2) ◽  
pp. 257-268 ◽  
Author(s):  
Erika F Latty ◽  
Charles D Canham ◽  
Peter L Marks

Beech bark disease has been a major cause of mortality of American beech (Fagus grandifolia Ehrh.) in North America during the past century. Previous studies have suggested a positive relationship between disease severity and both bark nitrogen content and tree size, presumably due to higher rates of infestation by beech scale insects, which allow more extensive infection of the tree by Nectria fungi. Recent concerns about nitrogen saturation in northeastern forests, particularly in old-growth forests, led us to examine patterns of disease severity as a function of bark tissue nitrogen content in old-growth and second-growth forests in the Adirondack region of New York and northern Maine. Trees growing in old-growth stands possessed significantly higher levels of bark nitrogen than similarly sized trees in second-growth forests. The severity of disease symptoms was more acute in the old-growth forests and was positively correlated with the percent nitrogen of the bark in both forest types. Comparisons of the coefficients of variation between beech bark sampled from disease-free forests in the upper peninsula of Michigan and that sampled from diseased forests indicated that elevated bark nitrogen concentrations in diseased trees were a cause and not an effect of disease presence. While there was no difference in disease severity between control and nitrogen-fertilized forests in Maine, these forests had both been exposed to the disease for longer time periods than the other studied forests and they are likely approaching nitrogen saturation.


2021 ◽  
Vol 9 (3) ◽  
pp. 541
Author(s):  
Holger Thüs ◽  
Pat Wolseley ◽  
Dan Carpenter ◽  
Paul Eggleton ◽  
Glen Reynolds ◽  
...  

Many lowland rainforests in Southeast Asia are severely altered by selective logging and there is a need for rapid assessment methods to identify characteristic communities of old growth forests and to monitor restoration success in regenerating forests. We have studied the effect of logging on the diversity and composition of lichen communities on trunks of trees in lowland rainforests of northeast Borneo dominated by Dipterocarpaceae. Using data from field observations and vouchers collected from plots in disturbed and undisturbed forests, we compared a taxonomy-based and a taxon-free method. Vouchers were identified to genus or genus group and assigned to functional groups based on sets of functional traits. Both datasets allowed the detection of significant differences in lichen communities between disturbed and undisturbed forest plots. Bark type diversity and the proportion of large trees, particularly those belonging to the family Dipterocarpaceae, were the main drivers of lichen community structure. Our results confirm the usefulness of a functional groups approach for the rapid assessment of tropical lowland rainforests in Southeast Asia. A high proportion of Dipterocarpaceae trees is revealed as an essential element for the restoration of near natural lichen communities in lowland rainforests of Southeast Asia.


2004 ◽  
Vol 82 (10) ◽  
pp. 1518-1538 ◽  
Author(s):  
Christine Roberts ◽  
Oluna Ceska ◽  
Paul Kroeger ◽  
Bryce Kendrick

Over 5 years, macrofungi from six habitats in Clayoquot Sound, Vancouver Island, British Columbia, were documented. Habitats were categorized as dune, spruce fringe, old-growth rainforest, second-growth forest, bog, or estuarine. All but the second-growth forest are natural ecosystems. A total of 551 taxa of macrofungi were recorded. Between 17% and 36% of the species in any one habitat were found only in that habitat. The most frequently encountered and ubiquitous species was Craterellus tubaeformis (Fr.) Quel., found in all years, habitats, and sites. Of the 551 taxa, only 28 were found every year, and 308 were found in only 1 year. Rare species that were recorded include Cordyceps ravenelii Berkeley & Curtis, Hygrophorus inocybiformis Smith, and Tricholoma apium Schaeffer in the dunes and Stereopsis humphreyi (Burt) Redhead in the spruce fringe. Similarities between habitats based on taxa in common showed that bog and estuarine habitats had only 9%–17% in common with each other and the other habitats, whereas dune, spruce fringe, and the two forest types shared 21%–31% of their species. Old-growth rainforest yielded approximately 4 times as many species as bog and estuarine habitats, and approximately 1.5 times as many as the other three habitats.Key words: Clayoquot Sound, Vancouver Island, macrofungi, habitats, biodiversity.


1983 ◽  
Vol 7 (4) ◽  
pp. 208-212 ◽  
Author(s):  
Robert N. Muller

Abstract An old-growth forest and a 35-year-old, second-growth forest on the Cumberland Plateau were studied to compare species composition and structure. Species composition and total basal area of the two stands did not differ, although total stand density was 19 percent lower and basal area of commercial species was 25 percent higher in the old-growth than in the second-growth stand. Analysis of size-class distributions showed that both stands were best represented by an inverse J-shaped distribution, which best describes old-age stands. The rapid regeneration of the second-growth stand seems to be the result of minimal disturbance to accumulated nutrient pools in the soil. The importance of these accumulated nutrient pools and implications for forest management on the Cumberland Plateau are discussed.


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