The assessment and condition of Fundy white birches in relation to ambient exposure to acid marine fogs

Abstract

The condition of white birches within 30 km of the Bay of Fundy, New Brunswick, have been monitored by the Canadian Forest Service since 1981, when an apparent deterioration in their condition and foliar browning was noticed. The apparent lack of associated insects or diseases that could have caused this change led to an investigation of possible environmental causes. Suspected variables were fog chemistry and frequency, rain chemistry, and ozone exposure. Significant (p = 0.05–0.01) spatial and temporal correlations of foliar browning with the fog frequency and fog chemistry variables have been detected, and their possible cause–effect relationship evaluated using both conventional on the ground sampling and remote sensing techniques. The use of remote sensing techniques, though not conclusive over the time it was carried out, did show the potential for future investigation of this type. In this study the deterioration of the two principal taxa, paper birch (Betulapapyrifera Marsh.) and mountain paper birch (Betulacordifolia Regel), were examined in terms of crown dieback and compared. These two taxa occur as separate stands or as a mixture in the birch plots. Comparisons of mortality responses of the two birch taxa together with results of leaf browning on transplanted young clones of the two taxa indicated a significantly (p < 0.001) greater sensitivity of B. cordifolia, whereas no significant differences between the taxa exist for percentage of trees with dieback. The potential role of sensitive indicators, such as B. cordifolia, as biomonitors of atmospheric change in an ecotonal situation like the Fundy coast is important, as these may give us the first indications of vegetation response to a changing chemical and physical environment.

Design and Application of an Intelligent Patrol Algorithm for Forest Management and Protection Based on Global Positioning System

“…Using the GPS, Zhao et al [12] determined the location range of a sample plot, and set up a new sample plot; the area of the new sample plot was calculated according to its geographic location and four corner signs; the total amount and dynamic change of forest resources are estimated in an accurate manner. Cox et al [13] probes deep into the diseases and pests in forests, and used the GPS to identify the location, distribution and other information about such disasters.…”

Composition and carbon dynamics of forests in northeastern North America in a future, warmer worldThis article is one of a selection of papers from NE Forests 2100: A Synthesis of Climate Change Impacts on Forests of the Northeastern US and Eastern Canada.

“…There is strong evidence that interception of this often highly acidic aerosol by red spruce foliage increases the risk of freezing injury by reducing frost hardiness of current-year needles by anywhere from 5 to 12 8C (reviewed by Schaberg and DeHayes (2000), and see ''Declines'' section below). Interception of acidic marine fogs with pH values as low as 3.0 has been documented in coastal red spruce and mountain paper birch (Betula cordifolia) stands adjacent to the Bay of Fundy in New Brunswick and Nova Scotia, and has been linked to episodes of birch foliar browning and early leaf loss due to leaf cuticular erosion followed by invasion by the leaf fungus Septoria betulae (Cox et al 1989(Cox et al , 1996Kouterick et al 2001). This periodic defoliation of coastal birches exacerbates their deteriorating condition caused by warmer winters (Bourque et al 2005, and see the ''Decline'' section).…”