Beech Saplings Research Articles

Suppression and Release During Canopy Recruitment in Fagus grandifolia

CANHAM, C. D. (Institute of Ecosystem Studies, Box AB, Millbrook, NY 12545). Suppression and release during canopy recruitment in Fagus grandifolia. Bull. Torrey Bot. Club. 1 17: 17. 1990.-Stem radial growth patterns were used to reconstruct the history of suppression and release during canopy recruitment of Fagus grandifolia Ehrh. (beech) in three old-growth northern hardwood forests. Overall, eighty percent of the cores showed periods of suppression prior to recruitment. The average number of periods of suppression in the 3 stands ranged from 1.9-2.4, and the average total length of suppression ranged from 45-52 years. At recruitment, trees averaged 66-80 years old with diameters of 5.1-7.4 cm at 1 m height. In comparison with Acer saccharum Marsh. (sugar maple) in the same stands, beech trees reached final release after fewer and shorter total length of suppression, and at much smaller sizes. Calculations using average height growth rates for suppressed and released saplings of both species suggest that beech saplings achieve half of their height at final release while suppressed, while growth of sugar maple saplings during suppression accounts for only 15% of their height at final release. The frequency and duration of periods of release in beech indicate that canopy gaps were shortlived relative to the time required for canopy recruitment in this shade-tolerant species, and that saplings responded to gaps created by the deaths of nearby canopy trees before replacing the canopy tree directly overhead.

Silvicultural Management of Beech and the Beech Bark Disease

Abstract Herbicides were used to control dense, advance reproduction of American beech and sprouting from roots and stumps of harvested beech in a northern hardwood stand in eastern Maine. Beech comprised 51% of the overstory basal area and was highly defective as a result of the beech bark disease. Beech saplings accounted for 80% of the advance reproduction. The herbicides glyphosate (Roundup®) or triclopyr (Garlon 3A®), applied using a backpack mist blower, were effective in reducing advance reproduction of beech by 100% and 93%, respectively. When applied in frills on larger beech six weeks prior to harvesting, glyphosate reduced the number of sprouts, two growing seasons after treatment, by 85%; triclopyr by 87%. Beech individuals believed to be resistant to infestation by the beech scale were left as a component of the residual overstory, along with sugar maple, red maple, yellow birch, and paper birch. The two-stage application of herbicides followed by shelter-wood harvesting is a strategy for managing stands dominated by defective beech. North. J. Appl. For. 3:89-91, Sept. 1986.

Succession of Epiphytic Bryophytes near Mountain Lake, Virginia

Twenty-five species of mosses and nine species of liverworts, mostly facultative epiphytes, were present on the bases of 140 saplings of six tree species in a cove forest. Epiphytic communities on saplings showed greater mutual simi- larity than did those on trees. Only one epiphytic species was restricted to one host species and only eight species showed strong single-host preferences. Most epiphytic communities on saplings were very dissimilar to those on mature trees of the same species. Epiphytic communities on oak, maple, beech, yellow birch, black birch, and hemlock saplings were most similar to epiphytic communities on mature black birches, while those on beech saplings were most similar to those on mature beeches. By comparing epiphytes on saplings and trees, successional trends could be inferred that led to the more sharply delimited host specificities of epiphytes on trees. These trends included: the persistence and expansion of some pioneer species, the disappearance of others, and the appearance of additional species that were not present on saplings; these additional species often showed strong host preferences and (especially on oak and maple) mesophytic growth- forms. The composition of epiphytic bryophyte communities on a tree changes as the tree ages. Such succession is probably caused by the growth of the tree and accompanying changes in bark characteristics and microclimate (Barkman 1958; Yarranton 1972). Host specificity of epiphytic bryophytes may be poorly developed both in very young trees where species-specific bark characteristics have not yet developed and on very old trees where differences have been obscured by the action of climatic factors over time (Barkman 1958). The objective of this study was to investigate the succession of epiphytic bryophytes by the indirect but convenient method of comparing species composition and host pref- erences of bryophytes on six species of saplings (red oak, red maple, beech, yellow birch, black birch, and hemlock) with those previously described (Studlar 1982) for mature trees of the same species from the same cove forest. Growth-form spectra of epiphytic com- munities on saplings and trees were also compared, since studies of terrestrial bryophytes have suggested correlations between changes in growth-form spectra and changes in mi- croclimate during succession (Birse & Gimingham 1955). METHODS Sampling methods. The study area, a cove forest along a creek (Pond Drain) near Mountain Lake, Virginia, was described in another study (Studlar 1982). Epiphytic bryophytes were collected from the bases (0-1.8 m) of 20 saplings for each of six host species at Pond Drain: Quercus rubra L. (red oak), Acer rubrum L. (red maple), Fagus grandifolia J. F. Ehrh. (beech), Betula alleghaniensis N. L. Britt. (yellow birch), Betula lenta L. (black birch) and Tsuga canadensis (L.) Carr. (hemlock). Saplings were defined as having diameters at breast height (DBH) of no more than 10 cm. The only

Reciprocal Replacement and the Maintenance of Codominance in a Beech-Maple Forest

Regeneration of dominant species in an undisturbed beech-maple forest in Michigan, USA, was studied. Spatial distributions of saplings of beech and maple were related to influence by canopy trees of these species. Some factor effecting a differential mortality of young individuals of the two species was indicated and it is suggested that this factor is related to species of nearby canopy trees. This cause of mortality appeared to act on individuals between one and four meters in height. Assuming that replacement of fallen trees in such a forest is primarily by advance reproduction in the form of such seedlings and saplings as studied here, it appears that individuals of either dominant species will tend to be replaced by individuals of the other species in a pattern of reciprocal replacement. This, then, is a possible mechanism for indefinite maintenance of codominance in a climax forest.

Effect of American Beech Trees on the Gamma Radioactivity of Soils

AbstractVarious factors that affect the distribution of gamma‐emitting radioisotopes in soils under mature American beech trees (Fagus grandifolia L.) were investigated. Because of its smooth bark and consequent greater amounts of stemflow this species concentrates more fallout radioisotopes in soil near its stem than most other species.Soil near the stems of beech trees contained considerably more fallout and was subjected to greater leaching of natural radioisotopes, to a depth of 30 cm or more, than soil not affected by stemflow water. Depth penetration of fallout and leaching of natural radioisotopes was greater in Dekalb fine sandy loam than in Bennington silt loam.Radioisotope distribution in soil under these trees was also affected by variations of stemflow around the stems, slope gradient, and the quantity and distribution of organic litter on the forest floor. Near two trees that had variable stemflow, the surface soil contained an average of five times more fallout on the high‐stemflow sides of the stems than on the low‐stemflow sides. Under a beech tree growing on a 20% slope, soil on the downslope side of the stem contained more fallout than soil on the upslope side. Organic litter had a much higher content of fallout than of naturally occurring radioisotopes.As a consequence of the greater concentrations of fallout, herbaceous plants, spicebush (Lindera benzoin L.), and American beech saplings growing near the stems of mature beech trees had higher uptakes of these radioisotopes than those growing farther from the stems.

THE ECOLOGICAL DISTRIBUTION OF MYCORRHIZA OF BEECH

SummaryThe following conclusions may be drawn from the determination of mycorrhizal spectra on beech at eight localities in Czechoslovakia. Altogether thirty‐three sub‐subtypes of ectotrophic mycorrhiza on beech were described in Czechoslovakia, of which seven are entirely new, namely: De, Df, Ed, Ee, Ek, Ih and Ik (see Dominik, 1959). Maximum frequencies of ectotrophic mycorrhizas were found down to a depth of 15–30 cm. With increasing depth the number of short roots and mycorrhizas decreased and the mycorrhizal spectrum narrowed. The quantities and types of humus were a decisive factor influencing mycorrhiza formation. Subtype E was the most frequent (20.26%) of all mycorrhizas. The richest mycorrhiza spectrum of four comparable localities was at Albrechtice in the Ore Mountains where fourteen sub‐subtypes of ectotrophic mycorrhiza were found despite a heavy deposition of industrial ash from power plants and a high concentration of SO2 in the atmosphere. No differences were found in the mycorrhiza variety between beech saplings (5–10 years) and older trees (over 100 years), nor was the occurrence of individual mycorrhiza strains characteristic of beech trees of different age.