Climate change has significant impacts on forests. Meteorological data show rising temperatures and changing precipitation patterns. In recent years, droughts have become more frequent.
Data from forest climate stations, located near the Level-II sites, provide high-resolution data on temperature, precipitation, wind, radiation, and humidity. Since precipitation can vary greatly over small areas, meteorological data that reflect the situation within the forest are valuable for analyzing the effects of weather and climate.
The weather affects various parameters that are recorded as part of intensive forest environmental monitoring. Time series over three decades show the influence of climate change on the recorded parameters:
Phenological observations track leaf emergence in spring and leaf fall in autumn. Depending on the weather, these phenological seasons shift.
Drought events can reduce the vitality of trees. Rising temperatures promote the spread of pests and tree infestations. Trees are dying more frequently. This is recorded in crown assessments.
The climatic conditions are reflected in the tree rings. Measuring the annual growth of some trees complements dendrological time series.
Ground-level ozone forms particularly strongly on hot summer days with strong solar radiation. Ozone leads to visible damage, the occurrence of which is recorded at forest edges near the Level II sites.
Temperature and precipitation influence the decomposition of organic matter and the availability of nutrients. The various interactions between material balance and climate change can be analyzed on the Level-II sites by monitoring different parameters.