Drought and Growth Sites

Beech (Fagus sylvatica)

The upper map shows the species-specific growth performance in this year relative to the average, historic data (2011-2020) of a site. Data are categorized as ‘high’ growth (dark green), ‘above average’ growth (green), ‘below average’ growth (light green), and ‘poor’ growth (yellow). Sites with mainly dormant trees are shown in grey.

The lower map shows the species-specific tree water deficit (drought stress) at the indicated date relative to the average, historic data (2011-2020) of a site. Data are shown in the categories of small water deficit ‘low TWD’ (dark blue), ‘below average’ water deficit (light blue), ‘above average’ water deficit (orange) and ‘high’ water deficit (red). When the temperature drops below zero, this can trigger what is known as frost shrinkage of the stem, indicated with a star.

Data source: TreeNet, automatic data analysis with filtered data set.

Norway spruce (Picea abies)

Pine (Pinus sylvestris)

Fir (Abies alba)

Oak (Quercus robur and petraea)

Downey oak (Quercus pubescent)

Maple (Acer spp)

Ash (Fraxinus excelsior)

Hornbeam (Carpinus betulus)

TreeNet Switzerland collects continuous data on stem radius fluctuations measured with point dendrometers from trees all over Switzerland and estimates drought and growth indicators for Swiss forest ecosystems. We closely collaborate with the Long-term Forest Ecosystem Research Programme (LWF/WSL), the ETHZ, the Institute for Applied Plant Biology (IAP), and the University of Basel.