Manual on methods and criteria for harmonized sampling, assessment, monitoring and analysis of the effects of air pollution on forests. Part XII Sampling and Analysis of Needles and Leaves

updated: 05/2020

Eberswalde

2020

18 S.

Bandaufführung

978-3-86576-162-0

18056BU

40002490

The aims of forest condition assessments are the monitoring of the health state of forests, and the detection of time trends and spatial patterns. Insight in the causes of changes can only be achieved if additional parameters from other ecosystem compartments are available. The nutritional state of trees is often indicative of processes at the ecosystem level. Inadequate nutrient supply may be a direct cause of low tree vitality or a factor which increases adverse air pollution effects. High concentrations of certain elements in the leaf or needle tissues may be the effect of intoxication or of high air-pollution levels. Unfavourable chemical conditions in the rooting zone of the soil may also lead to imbalances in the nutrient supply and subsequently to unbalanced nutrition of the trees. Thus, sampling and analysis of needles and leaves is essential. The analyses have to be performed at regular time intervals in order to establish potential relationships between changes in the stand condition and changes of the nutritional status. In the studies of intermediate or high intensity (see below), foliage sampling must be frequent enough to detect trends in the mineral nutrition of trees, not biased by interannual fluctuations in element concentrations.