Date of Award

8-2010

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Forest Resources

Advisor

Alan S. White

Second Committee Member

Robert S. Seymour

Third Committee Member

George L. Jacobson, Jr.

Abstract

Old-growth forests, although rare, exhibit a unique set of qualities and provide us with a benchmark to which biological change, environmental change, and harvesting impacts can be compared. Old-growth in Maine’s Acadian forest affords us the opportunity to study unique assemblages of species and community types reflecting its location between the boreal forests of the north and the temperate northern hardwoods to the south and west. The information obtained from this study should be useful for forest managers looking for quantitative data for future biodiversity conservation efforts and to inform developing ecology-based silvicultural systems.

In the first part of this study we identified multiple forest community types (including mixed wood forest, cedar swamps, cedar seepage forest, northern hardwood forest, red spruce-mixed wood forest, spruce forest, hemlock-mixed wood forest, and hemlock forest) in the Boody Brook Natural Area (BBNA) of northern Piscataquis County, Maine. To date, no other studies have synthesized multiple types of information regarding the “old-growthness” of this reserve. The community types were composed of shade tolerant to very tolerant species in the overstory, regeneration similar to overstory composition, abundant coarse woody material, trees of large diameters (>60 cm dbh), a reverse J-shaped diameter distribution, and shade tolerant gap fillers. Values reported in the reserve were comparable to the nearby Big Reed Forest Reserve although tree maximum size was larger in the BBNA due to differences in site quality and the abundance of large eastern hemlock which is lacking at Big Reed.

In the second part of this study, dendroecology was used to investigate the age dynamics and disturbances histories in the most common community types in the reserve. Dendroecological evidence indicated that stand replacing disturbances were absent and the average decadal percent canopy area disturbed varied between 5.9 and 11.2% in hardwood forests and spruce forests, respectively. No correlations were found between the average decadal disturbance rate in a given decade and composition, although communities with more red spruce tended to have a higher disturbance rate. Recruitment and disturbance rates were episodic and highest in the 1860s-1880s and 1920s-1940s. Higher recruitment and disturbance rates were linked to multiple host specific disturbance agents, such as birch dieback, spruce budworm, spruce bark beetle, and possibly selective harvesting. Beech bark disease was noted on all standing live and dead American beech trees. No evidence was found that linked any specific decades of recruitment and higher disturbances rates with hurricane-driven windthrow.

Forest managers looking to develop disturbance-based silvicultural systems in the more common Acadian forest types should note the residual composition (shade tolerant spp.), live basal area (28.9-34.5 m2 ha-1), and volume of coarse woody material (79.7-155.6 m3 ha-1) following small gap- creating (4.7-121.8 m2) disturbances which occur every 88 to 169 years. Larger patch-creating disturbances like those affiliated with wind throw are infrequent.

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