Showing 11 – 17 of 17 resources

Calcium and aluminum impacts on sugar maple physiology in a northern hardwood forest

Forests of northeastern North America have been exposed to anthropogenic acidic inputs for decades, resulting in altered cation relations and disruptions to associated physiological processes in multiple tree species, including sugar maple (Acer saccharum Marsh.). In the current study, the impacts of calcium (Ca) and aluminum (Al) additions on mature sugar maple physiology were evaluated at the Hubbard Brook Experimental Forest (Thornton, NH, USA) to assess remediation (Ca addition) or exacerbation (Al addition) of current acidified conditions. Fine root cation concentrations and membrane integrity, carbon (C) allocation, foliar cation concentrations and antioxidant activity, foliar response to a spring freezing event and reproductive ability (flowering, seed quantity, filled seed and seed germination) were evaluated for dominant sugar maple trees in a replicated plot study.

Asian Longhorned Beetle and its Host Trees

This pictorial guide provides basic information for identifying the Asian longhorned beetle, its injury characteristics, and its common host trees. The guide will help users detect the beetle in both urban and forested settings.

Influence of experimental snow removal on root and canopy physiology of sugar maple trees in a northern hardwood forest

Due to projected increases in winter air temperatures in the northeastern USA over the next 100 years, the snowpack is expected to decrease in depth and duration, thereby increasing soil exposure to freezing air temperatures. To evaluate the potential physiological responses of sugar maple (Acer saccharum Marsh.) to a reduced snowpack, we measured root injury, foliar cation and carbohydrate concentrations, woody shoot carbohydrate levels, and terminal woody shoot lengths of trees in a snow manipulation experiment in New Hampshire, USA. Snow was removed from treatment plots for the first 6 weeks of winter for two consecutive years, resulting in lower soil temperatures to a depth of 50 cm for both winters compared to reference plots with an undisturbed snowpack.

Associations of calcium and aluminum with the growth and health of sugar maple trees in Vermont

We compared tree growth and crown condition with soil and foliar elemental composition in 14 sugar maple (Acer saccharum Marsh.) stands in VT, USA, to evaluate if deficiencies or imbalances in cation nutrition were associated with growth and health reductions in native stands. The Till Source Model (TSM) was used to select study sites potentially high or low in calcium (Ca) by predicting the relative Ca concentration of soil parent material derived from glacial till. The TSM successfully identified high or low levels of soil Ca (P = 0.031) and foliar Ca (P = 0.011) among stands.

Long-term calcium addition increases growth release, wound closure, and health of sugar maple (Acer saccharum) trees at the Hubbard Brook Experimental Forest

We surveyed and wounded forest-grown sugar maple (Acer sacchamm Marsh.) trees in a long-term, replicated Ca manipulation study at the Hubbard Brook Experimental Forest in New Hampshire, USA. Plots received applications of Ca (to boost Ca availability above depleted ambient levels) or A1 (to compete with Ca uptake and further reduce Ca availability). We found significantly greater total foliar and membrane-associated Ca in foliage of trees in plots fertilized with Ca when compared with trees from Al-addition and control plots (P = 0.005).

Sugarmaker’s Guide to Pear Thrips Monitoring

Pear thrips surfaced as a new pest of sugar maple, Acer saccharum Marsh., in 1979. Damage from this insect occurs intermittently, and threatens the long-term health of maple trees throughout the northeastern United States and parts of Canada. A method for sampling forest soil to determine pear thrips populations is described that is suitable for sugarmakers. This method requires a minimum of equipment and time, and provides sugarmakers with a reliable estimate of the number of thrips in their sugar_bushes. By sampling and assessing damage annually, sugarmakers will gain an understanding of the relationship between thrips population levels and damage in their stands. Based on this information, potential damage in the spring can be estimated. Sample results are obtained before tapping so sugarmakers can adjust their management practices, such as the number of taps per tree, to minimize stress on trees when damage is likely.

Field Guide for Monitoring Sugar Maple Bud Development

The timing and duration of budbreak of forest trees may be affected by biotic and abiotic factors. This manual provides a visual method for monitoring bud development of mature trees of sugar maple, Acer saccharum Marsh., from the ground. A spotting scope with a 15-45x zoom lens was used for bud rating. The user is supplied with close-up photographs and a brief description of each bud stage. Sample data sheets are also provided. This protocol is currently used in the Vermont Forest Health Monitoring Program.