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Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sugar maple (Acer saccharum Marsh.) decline disease, decreased growth, and regeneration failure have been related to a low supply of Ca and Mg. There is increased interest in augmenting cation availability via liming, but there is little information on the amounts of lime required and the longevity of the lime treatment. A single application of 22.4 Mg ha-1 of dolomitic limestone in 1985 at four forested sites in Potter County, PA has shown that soil, soil water, and sugar maple foliage chemistry are significantly altered by liming and the changes in soils and foliage persist as long as 21-yr post-treatment. By 2001, only 3 kg ha-1 of lime remained undissolved while increases in exchangeable Ca and Mg, and pH continued through 2006 at depths up to 35 to 45 cm. Exchangeable Mn and Al concentrations were significantly reduced by lime application, though effects were slower to develop at deeper depths. Soil solution chemistry from 1996 was highly variable but reflected the changed soil nutrients. On limed plots, sugar maple foliage had elevated concentrations of Ca and Mg in 2006 samples, indicating the persistence of the lime treatment. Comparison of Ca/Al ratios in soil solution, soils, and foliage show inconsistencies from previous published risk thresholds. Species-specific thresholds of Ca and Mg availability in soil and foliage have better potential management application and should be more rigorously tested as stress indicators. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Shelterwood seed cutting in conjunction with herbicide site preparation has proven effective at regenerating Allegheny hardwood forests, but the long-term impact of this silvicultural system on herbaceous vegetation has not been determined. From 1994 to 2004, we studied the impacts of operational herbicide site preparation using glyphosate plus sulfometuron methyl herbicides in the context of a shelterwood seed cut. Our study took place on 10 partially cut sites on the Allegheny National Forest in northwestern Pennsylvania. Half of each site received herbicide and half did not in a split-plot design with repeated measures. Fences were erected after year six because deer impact had increased. Resilience of individual species and the community were determined using measures of percent cover by species or species groups and indices of diversity and similarity comparing post-treatment to pre-treatment conditions and controls. In the short term, abundance of all species was reduced and there were four fewer species on average in treated areas. No species was eliminated by herbicide across all sites in the long term. Graminoids were more abundant on treated plots after year six. Targeted ferns remained less abundant on treated than control plots after 10years. Species richness recovered within 4years following treatment. Shannon Diversity and Shannon Evenness were greater in treated than in control plots over the full study period, but the differences were not significant in any single year. The richness-based Jaccard index of similarity did not differ between control and treatment plots after year two, while relative abundance influenced indices showed significant differences through year eight. Results suggest that herbaceous layer vegetation is resilient to the disturbance created by herbicide-shelterwood treatments. [Copyright &y& Elsevier]

Sugar maple ( Acer saccharum Marsh.) is a keystone species in the northern hardwood forest, and decline episodes have negatively affected the growth and health of sugar maple in portions of its range over the past 50+ years. Crown health, growth, survival, and flower and seed production of sugar maple were negatively affected by a widespread decline event in the mid-1980s on the unglaciated Allegheny Plateau in northern Pennsylvania. A long-term liming study was initiated in 1985 to evaluate responses to a one-time application of 22.4 Mg·ha-1 of dolomitic limestone in four northern hardwood stands. Over the 23-year period ending in 2008, sugar maple basal area increment (BAINC) increased significantly ( P ≤ 0.05) in limed plots from 1995 through 2008, whereas American beech ( Fagus grandifolia Ehrh.) BAINC was unaffected. For black cherry ( Prunus serotina Ehrh.), the third principal overstory species, BAINC and survival were reduced in limed plots compared with unlimed plots. Foliar Ca and Mg remained significantly higher in sugar maple foliage sampled 21 years after lime application, showing persistence of the lime effect. These results show long-term species-specific responses to lime application. [ABSTRACT FROM AUTHOR]

The article discusses the study on the management of white-tailed deer found at the forest sites of northwestern Pennsylvania which causes damage on forest vegetation, crops, and wildlife habitat. It shows their is no negative effects on vegetation despite of deer densities but species resilient to browsing have indirect effects on plants.

Determines the effects of lime fertilization on sugar maple in Pennsylvania. Responses of tree vitality to lime additions; Changes in foliar and soil elements; Correlation between tree growth and crown vitality.