A Survey of the Health of Fagus sylvatica in Southern Britain

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Summary1. This survey examined the health of beech (Fagus sylvatica) trees at 72 survey sites in southern Britain. Tree health was assessed using crown thinness, crown architecture and leaf chlorosis as criteria. Diverse variables including soil and stand characteristics were recorded. Relationships were sought between tree health and local site conditions, regional climate and pollution levels.2. Approximately 25% of all beech trees surveyed were in poor health as assessed by crown thinness and architecture. The incidence of chlorosis was generally low at 5%. The different assessment techniques showed markedly different geographical distributions, suggesting that they are not measuring responses to the same environmental variables. Sites of high nature conservation interest for beech showed substantially poorer tree health than other sites. 3. Differences in local environmental conditions could explain much of the variation in levels of beech health. Disturbance, tree age, the openness of the stand and soil characteristics, especially pH and drainage properties, were closely linked to tree health as assessed by crown thinness and architecture. The incidence of chlorosis was most closely associated with the amount of free calcium in the top soil. 4. Crown thinness was positively related to S02 concentration, whereas crown architecture was better in areas with a high concentration of NH3. Trees had thinner and more chlorotic crowns where they had experienced the most intense drought in 1976. 5. For all cases where significant relationships were found between pollutant levels and tree health on acidic soils, health was worse on sites receiving high levels of the pollutant concerned. In contrast, on calcareous soils tree health was better with higher levels of pollutants. The relationship between air pollution and tree health on acidic soils is consistent with the soil acidification hypothesis that has been proposed to explain forest decline.

Effects of elevated CO2 on leaf gas exchange in beech and oak at two levels of nutrient supply: consequences for sensitivity to drought in beech

“…The potential for enhanced growth and productivity in elevated CO2, and the associated feedback to the global carbon cycle, could be more than offset by any adverse effects on tree water balance. Even a slight reduction in drought tolerance could contribute to long-term decline; this is an important consideration, since the health of beech has been declining over recent decades, both in continental Europe (Innes 1992b) and in southern Britain (Ling, Power & Ashmore 1993). One of the factors most strongly correlated with the decline of beech in the UK was the severity of drought 57 experienced in 1976 -and, probably, in subsequent years such as 1983-84 (Ling et al 1993).…”

“…Even a slight reduction in drought tolerance could contribute to long-term decline; this is an important consideration, since the health of beech has been declining over recent decades, both in continental Europe (Innes 1992b) and in southern Britain (Ling, Power & Ashmore 1993). One of the factors most strongly correlated with the decline of beech in the UK was the severity of drought 57 experienced in 1976 -and, probably, in subsequent years such as 1983-84 (Ling et al 1993). Peterken & Mountford (1996) found that, following the 1976 drought, the growth rate of damaged beech trees was negligible for 12 years and never fully recovered; trees were still dying from drought-induced damage up to 15 years later.…”

Impacts of Beech Bark Disease and Climate Change on American Beech

“…In European beech, calcareous soils seem to counteract the potentially negative effect of certain pollutants [14]. Decline of overall forest health due to soil acidification and intense agricultural fertilizer continues in both Europe and North America.…”

“…One particular study used the extent of crown thinness, overall crown architecture and leaf color to determine the health of beech in different environments. A significant negative impact on crown chlorosis in response to drought and particularly high summer temperatures was documented [14].…”

“…Structural (endogenous to host) Stone cell layers of cortex may provide structural barrier(s) to scale stylet [80] Structural (exogenous to host) Forest type and forest dynamics [81] Forest structure [38] Species composition and site factors [82] Nutritional access (pathogen perspective) Nutrition partitioning allows tree to discourage infestation [40] Higher bark nitrogen may provide more desirable habitat for the beech scale [65,66] Nutritional availability (host perspective) Nutrients and water [26] Drought conditions [14] Differential gene expression Differential gene expression in disease resistant versus BBD-susceptible beech trees [62,76] Location attributes Stand-level [28] In considering the influence of climate change in synergy with disease pathology, it is necessary to consider all the environmental factors that may be influenced or linked to climate change within the context of both physical parameters (slope, aspect, etc.) and genetic conditions that may predispose trees to susceptibility or resistance.…”