Treesearch

Lists the organisms, both plant and animal, that have been identified by scientists engaged in multidisciplinary ecological research in the Hubbard Brook Valley, New Hampshire, during the past three decades. The Valley encompasses the Hubbard Brook Experimental Forest, Mirror Lake, and nearby areas within the White Mountain region of Grafton County. The species lists included in this report are relatively complete for vascular plants, amphibians, birds, fish, mammals, phytoplankton, and zooplankton, and partially complete for insects, molluscs, and nonvascular plants.

Two-aged management is receiving increasing consideration by central Appalachian hardwood managers as a tool to accomplish multiple landowner goals. On non-industrial private forests where aesthetics are often important, two-aged management has the attribute of retaining some relatively large trees on the area at all times. For many landowners this is critical. Research at the Fernow Experimental Forest near Parsons, West Virginia, shows the two-aged system can also provide a means of obtaining desirable regeneration of species that are both tolerant and intolerant of growing beneath...

Quantitative data on the composition and structure of the overstory tree (stems ≥ 10cm - dbh) and understory tree strata (≥2.5 but < 10 cm dbh) were obtained from 105 - 0.1 ha plots in the allegheny plateau of west virginia. fifteen species occurred as the leading dominant in at least one plot for the overstory, but Quercus rubra (northern red oak) was the overall dominant and had the greatest importance value in 25 of the 105 plots. Acer saccharum (sugar maple), Fagus grandifolia (beech), and Acer rubrum (red maple) were the usual dominants in the understory. Ordination analysis using...

The impact of experimental watershed acidfication on xylem cation chemistry was evaluated in eight tree species at two sites in West Virginia (Clover Run and Fernow) and one site in Maine (Bear Brook). All sites had received regular additions of (NH4) SO4 equivalent to twice the ambient annual wet plus dry atmospheric deposition of N and S. Multiple wood cores were extracted from tree boles in five trees of each species on treatment and control areas at each site with increment borers. Cores were divided into several age segments and composited for each tree. Ground wood samples were...

When harvested, red spruce (Picea rubens) at low elevations is vulnerable to temporary displacement by balsam fir (Abies balsamea) and hardwoods. If indicator plants can be found by which to assess spruce regeneration habitat, then biota dependent on red spruce dominance could benefit. Associations between spruce seedlings (0.1-0.5 m tall) and understory plants, species life histories, and successional processes can be considered in managing for biodiversity; species richness alone is inadequate.Data from eight Maine sites in 50 permanent 0.0625 ha plots and 600 1 m2 subplots along a...

Stands structure was examined in evenaged northern hardwoods in New Hampshire in terms of diameter distribution (numbers of trees by dbh class) and spatial distribution of basal area by species. Diameter distributions by species and for all species combined were graphed for stands varying in age class from 7-9 yr up to 60-68 yr. Over time, these northern hardwood stands develop a layered canopy structure with the intolerant and short-lived paper birch and aspen dominating the larger size classes and exhibiting a bell-shaped diameter distribution. Longer lived species, most abundant in the...

Buried mineral soil-bag,, and natural solutions were studied as indicators of forest ecosystem response to elevated N and S inputs at the Bear Brook Watershed in Maine (BBWM). The BBWM is the site of a paired watershed manipulation experiment in a northern New England forested ecosystem. The study includes two small (~10 ha each) catchments dominated by northern hardwood forests with red spruce in the upper elevations. Treatments consist of (NH4)2SO4 applied to the West Bear watershed six times per year, increasing N and S deposition 3x and 2x above ambient values, respectively. Buried...

Effects of increased soil temperature on soil microbial biomass and dehydrogenase activity were examined on organic (O) horizon material in a low-elevation spruce-fir ecosystem. Soil temperature was maintained at 5 °C above ambient during the growing season in the experimental plots, and soil temperature, moisture, microbial biomass, and dehydrogenase activity were measured during the experiment. An incubation study was also conducted under three temperature regimes, 5, 15, and 25 °C, and under four moisture regimes of 20, 120, 220, and 320% to further evaluate these environmental factors...

Dry (NH4)2SO4 (1,800 eq-1 ha-1 yr-1) has been applied to the western of two contiguous 10 ha catchments at the Bear Brook Watershed in Maine (BBWM) since November, 1989. The initial rapid and significant response in both S and N in West Bear, compared to the reference East Bear, slowed after three years. Annual S retention of the total experimental treatment decreased from 86 to 34%, with a seven year cumulative retention of 59%. Hydrology influences the export flux of S; S is retained more in dry seasons and dry years. The annual retention of N has decreased from 96 to 81%, with a...

The ice storm of January 1998 affected 17 million acres of forestland in northern New York, Vermont, New Hampshire, and Maine, including parts of the Green Mountain National Forest and the White Mountain National Forest. Portions of eastern Canada were also impacted, especially Quebec. The weight of accumulated ice caused trees to snap off or bend over to the ground. Large branches broke within crowns and debris littered the landscape. Meteorologists have called the ice storm a 100-year event, and many compare it to the hurricane of 1938 with respect to damage to the region's forests.