Scots Pine (Pinus sylvestris L.) Crown Defoliation in Relation to the Acid Deposition and Meteorology in Lithuania

Abstract

ICP Forest Monitoring data collected for more than 10 years made it possible to analyse key factors responsible for changes in forest conditions on a regional European scale. Observation routines may vary between different countries, which makes it difficult to gain more insight into stress-effect relationships. The effects on defoliation of Scots pine (Pinus sylvestris L.) of air concentrations and wet deposition of acidifying compounds, as well as effects of meteorological, site, stand and tree variables were investigated in Lithuania to test the hypothesis that spatial and temporal changes in pine defoliation were closely associated with atmospheric inputs of acidity. Over the period 1994-2004 crown defoliation of more than 8,000 pine trees was monitored in totally 45 stands distributed among three National Parks, where Integrated Monitoring Stations were situated. Air concentrations of SO2, and SO 2À 4 and NH þ 4 deposition, as well as spring and summer precipitation and mean winter temperature were shown to be the key factors affecting defoliation. The acidifying compounds accounted for nearly 58% of the variance in pine defoliation. Meteorological factors increased the degree of explanation to 65%, and stand and site variables to 79%.

Structure, regeneration and growth of Scots pine (<i>Pinus sylvestris</i> L.) stands with respect to changing climate and environmental pollution

“…Within the CR, the Třebechovicko microregion can be characterised as a medium polluted area both for sulphur and nitrogen (Hůnová 2001;Hůnová 2003), and also for ambient O 3 (Hůnová and Schreiberová 2012). Despite this and in accordance with other research results (Vacek and Podrázský 1994;Augustaitis et al 2007), SO 2 concentrations and N deposition in combination with extreme climate events causes sever defoliation in pine stands. Since the reaction of trees to the impact of climatic factors in the polluted environment is more sensitive (Juknys et al 2002), weakened forest stands can react on changing climate conditions characterised by longer drought periods by lowering their ecological stability, however the number of signal years is higher in healthy environmental conditions (Wilczyński 2006).…”

“…The drought stress shown by the negative correlation between diameter increment and average temperature of both the actual and preceding vegetation period was one of the main environmental stresses affecting the tree growth. Comparing other studies from the Mediterranean environment, from the Alps and from the boreal regions (Augustaitis et al 2007;Oberhuber et al 1998;Bogino et al 2019) drought is a determining factor in the radial growth of Scots pine also in Central European conditions. Similarly, in northeast lowlands of Brandenburg (Germany), for the needle production of Scots pine both autumn precipitation of the previous year and summer precipitation are important predictors, whereas temperature seems to have a minor impact on needle parameters (Insinna et al 2007).…”

The seasonal variability of air pollution effects on pine conditions under changing climates

“…Over the past 30 years, scientists have gained greater insight into the ways in which air pollutants, including ozone and acidic deposition, alter forest ecosystems (Knabe 1981;Bauer 1982;Mehne-Jakobs 1990;Klap et al 1997Klap et al , 2000De Vries et al 2000, 2003aDriscoll et al 2003). The findings of our earlier study allowed us to make an assumption that temporal and spatial changes in pine defoliation are first of all, related to air concentrations of the acidifying compounds, their deposition and meteorology, while ozone concentrations proved to reinforce the integrated impact of these factors (Augustaitis et al 2005(Augustaitis et al , 2007; Augustaitis and Bytnerowicz 2008). However, in estimating the effect of air pollutants and their deposition on forest conditions, only the mean annual value of air pollutants and sum deposition over the year, or sum concentrations of ozone from April to September is usually used (Klap et al 1997De Vries et al 2000).…”

Defoliation triggered by climate induced effects in Spanish ICP Forests monitoring plots

“…The defoliation data obtained from the forest monitoring plots of the European network have led to the publication of numerous studies in various countries such as Finland (Nevalainen et al, 2010), France (Ferretti et al, 2014), Italy (Bussotti et al, 2003), Lithuania (Augustaitis et al, 2007), Norway (Aamlid et al, 2000) and Spain (Peñuelas et al, 2001). In forest regions of Northern and Central Europe, woodlands have suffered serious damage due to chemical contaminants in the atmosphere (Juknys et al, 2013).…”