Thad E. Yorks

Vascular plant propagule banks of six eastern hemlock stands in the Catskill Mountains of New York.

eastern hemlock (Tsuga canadensis) stands in the Catskill Mountains of New York. Soil samples were collected and observed in a glasshouse; germinants were identified and removed over a one year period. Yellow birch (Betula alleghaniensis) seeds, evergreen woodfern (Dryopteris intermedia) spores, and hay-scented fern (Dennstaedtia punctilobula) spores germinated in abundance from the propagule banks (means of 722, 2858, and 296 m-2, respectively) even though hay-scented fern only occurred in the understory of one stand. Seed densities were intermediate and propagule species richness values were low compared to previous studies of northeastern forests. Existing vegetation was also characterized; hemlock was the dominant tree species in all stands (6787% of basal area), with lesser abundances of red maple (Acer rubrum), yellow birch and/or American beech (Fagus grandifolia). Striped maple (Acer pensylvanicum), red maple, yellow birch, evergreen woodfern, shining clubmoss (Lycopodium lucidulum), and common wood sorrel (Oxalis acetosella) occurred in understories of most stands. Understory vegetation and propagule banks indicated potential stand replacement by evergreen woodfern and, eventually, yellow birch in the event of a major disturbance leading to hemlock mortality. However, hay-scented fern could become abundant if woody species are over-browsed by white-tailed deer.

UNDERSTORY VEGETATION-ENVIRONMENT RELATIONSHIPS IN CLEARCUT AND MATURE SECONDARY FORESTS OF WESTERN MARYLAND

Abstract Understory vegetation of 17 clearcuts 1 to 26 years old and three mature secondary forests in Garrett County, Maryland was sampled during the summer to investigate species composition and abundance during forest regeneration. Canonical correspondence analysis (CCA) was used to determine which measured environmental variables (EVs) were significantly related to species distributions among the sites and to characterize species abundances along these environmental gradients. Stand age and site moisture were the most important EVs related to species distributions. Biplots of EV vectors and species scores indicated early successional and shade-associated species (e.g. Rubus spp. and Arisaema triphyllum, respectively) that were most abundant in recent clearcuts (<10 yr old) and shade-associated species that were most abundant in older clearcuts and mature stands. Early successional species declined or disappeared as regenerating tree canopies started to close. Species distributions were significantly related to site moisture despite the broad range of light availability associated with differences in stand age and overstory basal area among the study sites.

Arboreal vegetation, coarse woody debris, and disturbance history of mature and old-growth stands in a coniferous forested wetland1

Abstract Forrester, J. A. (SUNY, College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210-2778), T. E. Yorks (Environmental Studies Program, Cazenovia College, 22 Sullivan Street, Cazenovia, NY 13035) and D. J. Leopold (SUNY, College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210-2778). Arboreal vegetation, coarse woody debris, and disturbance history of mature and old-growth stands in a coniferous forested wetland. J. Torrey Bot. Soc. 132: 252–261. 2005.—We quantified the forest age and tree size structure of an old-growth and mature stand in a coniferous forested wetland in central New York, USA. We also determined the volume and decay class distribution of standing and downed coarse woody debris. The old-growth stand contains eastern white pine (Pinus strobus L.) > 400 years old and other species > 200 years old. Live tree basal area in the old-growth area (36 m2·ha−1) was dominated by approximately equal amounts of balsam fir (Abies balsamea (L.) Miller.), eastern white pine, and northern white-cedar (Thuja occidentalis L.; 11, 10, and 10 m2·ha−1, respectively), but eastern white pine was less abundant in the mature stand. Snag basal area was 7 m2·ha−1 in the old-growth and mature stands and was dominated by balsam fir and northern white-cedar. Total coarse woody debris (CWD) volumes were 145 and 83 m3·ha−1 in the old-growth and mature stand, respectively. The decay class distribution in each area was skewed toward advanced decay classes. Most CWD was in the form of logs and snags in both areas, but snag volume in the old-growth area was approximately 3 times that in the mature stand (75 vs. 26 m3·ha−1). In both stands, balsam fir and northern white-cedar each accounted for 21–30% of total CWD. Eastern white pine contributed 28% of the CWD in the old-growth area but was not present as CWD in the mature stand. Both forests are uneven-aged, with the earliest species establishing in the 1600s and 1750s for the old-growth and mature stands, respectively. No species exhibited major growth releases in the old-growth or mature stands, but several exhibited moderate releases. The age and diameter distributions of the old-growth area suggest that no stand-initializing disturbances have affected the forest for at least 250 years. Instead, fine-scale treefall gaps created by single or multiple treefalls are the dominant mode of regeneration in this forest.

Restoration cutting as a management tool for regenerating Pinus banksiana after ice storm damage

Abstract In January 1998, an ice storm caused extensive and severe crown damage to the rare Pinus banksiana – P. rigida barrens in northeastern New York. These barrens contain some of the southernmost populations of P. banksiana and northernmost populations of P. rigida in the eastern US. Because P . banksiana showed particularly severe damage compared to P. rigida , and P. banksiana regeneration is absent or sparse in these stands, there is concern that P. banksiana importance may be dramatically reduced in severely damaged stands. In an attempt to reduce the risk of wildfire and to regenerate P. banksiana in such stands, restoration cuttings were completed in 1998 and 1999. Restoration cutting consisted of whole-tree harvesting (i.e. harvest of boles and attached branches) of nearly all standing trees, while branches and attached cones broken during the ice storm were left on-site as a seed source. In restoration cuttings, there were 23,400–39,800 P. banksiana seedlings/ha 2 years after harvesting, while few or no P. banksiana seedlings were observed in uncut damaged stands. P. banksiana seedling densities were several times as high in plots with evidence of soil scarification than in unscarified plots (54,000–63,600 and 12,100–30,300 P. banksiana seedlings/ha, respectively). Regeneration was positively related to cone density and negatively related to shrub and herbaceous species percent cover (e.g. R =0.30 and −0.55, respectively, for the 1999 cut), indicating the importance of even dispersal of cone-bearing slash and the reduction of competing vegetation. Restoration cutting can be used to regenerate P. banksiana in stands severely damaged by ice storms or other canopy disturbances (e.g. blowdown) if soils are adequately scarified and harvesting is conducted within a few years after canopy damage.

Effects of cold storage on anion, ammonium, and total nitrogen concentrations in soil water.

Abstract Researchers frequently must store water samples >24 h after collection until chemical analyses can be accomplished. Samples are commonly stored in darkness at near‐freezing temperatures until analysis, but effects of this storage method on soil water chemistry are not well‐documented. Soil water samples were collected from eastern hemlock [Tsuga canadensis (L.) Carriere] stands and analyzed initially and over time to determine if nitrate (NC3 ‐), chloride (Cl‐), sulfate (SO4 2‐), ammonium (NH4 +), and/or total nitrogen (TN) concentrations changed when samples were stored in darkness at 2–4°C. Subsamples were analyzed <24 h after collection and reanalyzed five times in a 12 to 24 wk period following sample collection. Nitrate concentrations remained stable for at least one wk and were only slightly lower than initial concentrations after 3–16 wk of storage. Chloride and SO4 2‐ remained stable for 16 wk, while TN remained stable for 8 wk and decreased slightly after 24 wk. Most NH4 + concentrations were below the limit of quantification, but concentrations of samples with quantifiable NH4 + decreased in the first week of storage. Overall, cold storage in darkness was effective for preserving NO3 ‐, Cl‐, SO4 2‐, and TN concentrations in soil water, but NH4 + analyses should probably be performed as soon as possible after sample collection.

Current status and future development of the only Chamaecyparis thyoides (Atlantic white-cedar) population in Pennsylvania.

ABSTRACT: We assessed the current status and potential future development of the only Atlantic white-cedar (Chamaecyparis thyoides) population in Pennsylvania (Spruce Flats Bog in Westmoreland County). We counted all stems in the population and measured the diameter at breast height of all stems ≥ 1.4 m in height. Increment cores were collected and analyzed from 93 trees to quantify age distribution. We also evaluated relationships among cedar regeneration, microtopography, and other potentially competitive vegetation. Potential recruitment from the seed bank was assessed via the germination method using soil samples from 46 hummocks in the bog. The population consisted of 395 stems with stem size structure characterized by an “inverse-J” distribution; most stems (67%) were < 1.4 m in height. The oldest individuals were established in the 1940s, but recruitment has been steady since initial establishment. Hummock area and mean height above the water table were positively related to the abundance of C. thyoides. No C. thyoides seeds germinated from soil samples during a 14-month period, indicating that the bogs seed bank may have limited potential to contribute to recruitment. We suggest that this population has naturalized from plantings in the 1940s, with most recent recruitment having been vegetative. Because of previous extirpation of C. thyoides from Pennsylvania wetlands, the naturalization of this population has conservation value. Although the population size is probably limited by the number of microsites sufficiently high above the water table to avoid excessive inundation, direct management of this population does not currently appear to be necessary in order to ensure its continued survival.