Adaptation of forest ecosystems to air pollution and climate change : a global assessment on research priorities.

Climate change and air pollution are two of the anthropogenic stressors that require international collaboration. Influence mechanisms and combating strategies towards them have similarities to some extent. Impacts of air pollution and climate change have long been studied under IUFRO Research Group 7.01 and state of the art findings are presented at biannual meetings. Monitoring, modelling, assessment of multiple stressors, ecophysiology, and nutrient cycles have been thoroughly studied aspects of climate change and air pollution research for a long time under the umbrella of IUFRO RG 7.01. Recently, social and economic issues together with water relations are gaining more attention in parallel with science requirements on adaptation. In this paper, we summarise the main research needs emphasized at the recent 24th IUFRO RG 7.01 Conference titled ?Adaptation of Forest Ecosystems to Air Pollution and Climate Change?. One important conclusion of the conference was the need for information on nutritional status of forest stands for sustainable forest management. It has been suggested to maintain long-term monitoring programs and to account for the effects of extreme years, and past and present management practices. Long-term monitoring can also help to understand the effects of forestry treatments on the nutrient and water budgets of the ecosystems which may enable to improve management practices like water saving silviculture

SEASONAL CHANGES IN STREAM WATER QUALITY AND ITS EFFECTS ON MACROINVERTEBRATE ASSEMBLAGES IN A FORESTED WATERSHED

In this study, indicator macroinvertebrate individuals was used in water quality assessments due to their broad spectrum of responses of macroinvertebrates individuals with specific tolerance limit values and preferences to changes in environmental factors. Because of their indicator properties, the interactions of macroinvertebrates individuals collected from an experimental watershed in Belgrad Forest of Istanbul and sixteen environmental variables were evaluated by using principle component analysis (PCA). We concluded that stream water quality parameters should be coupled with number of macroinvertebrate individuals in order to establish the linkage between hydrochemistry with biota. Axes to be evaluated in PCA analysis were determined to defined that both of F1 (53%) and F2 (29%) axes explain 82% of total variance together. All macroinvertebrate individuals and dissolved oxygen were found to be loaded positively loaded to Factor 1 but electrical conductivity, total hardness, alkalinity, HCO3, organic matter and potassium, loaded negatively to Factor 1. Water temperature, runoff, pH, turbidity, magnesium (Mg), sodium (Na), nitrate nitrogen (N-NO3) and ammonium nitrogen (NH4-N) and some individuals (Gerris lacustris and Perlodes microcephala) highly loaded to F2. UPGMA analysis was determined to similarity on numbers of macro invertebrate individuals in order to perform a seasonal evaluation. According to Output UPGMA dendrogram, the different number of macroinvertebrate individuals can be seen as the reflect of variable seasonal effec

Effect of selective cutting on streamflow in an Oak-Beech forest ecosystem

Calibration equations for streamflow between the control (W-I) and the treatment (W-II) watersheds as an integral part of a paired experimental watershed study in Belgrad Forest are presented. Correlation coefficients of the calibration equations were found to be highly significant. The effect of 11% removal of the standing volume by regular selective cutting in old-growth oak-beech forest ecosystems was discussed. Streamflow hydrographs were developed for March, April, May, and June of 1986, and for the long-term period from 1986 to 1996. Increase in water yield immediately after the treatment was detected as the difference between measured and predicted values. Significant increases occurred in streamflow in March 1986 and in the long-term period (1986-1996)

New functions for estimating AOT40 from ozone passive sampling

AOT40 is the present European standard to assess whether ozone (O-3) pollution is a risk for vegetation, and is calculated by using hourly O-3 concentrations from automatic devices, i.e. by active monitoring. Passive O-3 monitoring is widespread in remote environments. The Loibl function estimates the mean daily O-3 profile and thus hourly O-3 concentrations, and has been proposed to calculate AOT40 from passive samplers. We investigated whether this function performs well in inhomogeneous terrains such as over the Italian country. Data from 75 active monitoring stations (28 rural and 47 suburban) were analysed over two years. AOT40 was calculated from hourly O-3 data either measured by active measurements or estimated by the Loibl function applied to biweekly averages of active-measurement hourly data. The latter approach simulated the data obtained from passive monitoring, as two weeks is the usual exposure window of passive samplers. Residuals between AOT40 estimated by applying the Loibl function and AOT40 calculated from active monitoring ranged from +241% to -107%, suggesting that the Loibl function is inadequate to accurately predict AOT40 in Italy. New statistical models were built for both rural and suburban areas by using non-linear models and including predictors that can be easily measured at forest sites. The modelled AOT40 values strongly depended on physical predictors (latitude and longitude), alone or in combination with other predictors, such as seasonal cumulated ozone and elevation. These results suggest that multi-variate, non-linear regression models work better than the Loibl-based approach in estimating AOT40

Effect of timber harvest on physical water quality characteristics

The effect of 11% thinning on selected stream water properties in an oak-beech forest ecosystem in the Belgrad Forest of Istanbul, Turkey was studied with a paired catchment experiment. Regression equations for some physical properties of the stream water were developed between control (W-I) and treatment (W-II) watersheds for calibration (with their 95% confidence limits) and treatment periods. The study discovered significant linear regressions between control and treatment watersheds for color, turbidity, air and water temperatures, suspended sediment concentration, pH and electrical conductivity in the calibration period but not turbidity and suspended sediment concentration in the treatment period. The impact of the timber removal was calculated as the difference between measured and predicted values derived from calibration equations. Results showed that timber harvest caused significant decreases in the color, turbidity, temperature, pH, and electrical conductivity values of the stream water and air temperature under the canopy but did not affect the suspended sediment concentration in the stream water

Cover and management factors for the Universal Soil-Loss equation for forest ecosystems in the Marmara region, Turkey

The Universal Soil-Loss Equation (USLE) predicts annual soil loss from agricultural uplands under specified land use and management conditions. Recently, some attempts have been made to apply USLE to forest lands in Turkey. This regional application of USLE and its reliability should be tested against measured data, especially for forest ecosystems. Our objective was to compute the cropping management (C) and the support practice (P) factors of the equation together in a single numerical value as a cover and management factor (CP) for forest and pseudo-maqui ecosystems using the local watershed and plot experiments carried out in the vicinity of Istanbul. CP factors were computed using known (rainfall erosivity factor, R) and estimated numerical values of other factors (average annual soil loss, A; soil-crodibility factor, K; combined slope-length and slope-steepness factor, LS). The CP factors were found to be 0.021 for old-growth oak-beech forest ecosystem in watershed-I and pseudo-maqui ecosystem and 0.011 for forest ecosystem in watershed-II. (c) 2005 Elsevier B.V. All rights reserved

Estimation of Interception Loss from Forests by using LAI

Water production is simply a function of precipitation and evapotranspiration (ET). It is essential to quantify ET and/or its components in regional scale for water resources assessments or functional forest plans. Several models that combine empirical equations, field measurements and remote sensing data have been tested and proposed to achieve this. One of the major parameters in ET estimatons is the leaf area index (LA I). LAI is a key parameter to identify the water consumption of forest stands and thus ET. It is however quite variable in temporal and spatial scales