DOI: 10.5061/dryad.ns1rn8q07
title: Climate‐driven tree growth and mortality in the Black Forest, Germany: Long‐term observations

description: Episodic tree mortality can be caused by various reasons. This study
 describes climate‐driven tree mortality and tree growth in the Black
 Forest mountain range in Germany. It is based on a 68‐year consistent data
 series describing the annual mortality of all trees growing in a forest
 area of almost 250 thousand ha. The study excludes mortality caused by
 storm, snow and ice, and fire. The sequence of the remaining mortality,
 the so‐called “desiccated trees,” is analyzed and compared with the
 sequence of the climatic water balance during the growing season and the
 annual radial growth of Norway spruce in the Black Forest. The annual
 radial growth series covers 121 years and the climatic water balance
 series 140 years. These unique time series enable a quantitative
 assessment of multidecadal drought and heat impacts on growth and
 mortality of forest trees on a regional spatial scale. Data compiled here
 suggest that the mortality of desiccated trees in the Black Forest during
 the last 68 years is driven by the climatic water balance. Decreasing
 climatic water balance coincided with an increase in tree mortality and
 growth decline. Consecutive hot and dry summers enhance mortality and
 growth decline as a consequence of drought legacies lasting several years.
 The sensitivity of tree growth and mortality to changes in the climatic
 water balance increases with the decreasing trend of the climatic water
 balance. The findings identify the climatic water balance as the main
 driver of mortality and growth variation during the 68‐year observation
 period on a landscape‐scale including a variety of different sites. They
 suggest that bark beetle population dynamics modify mortality rates. They
 as well provide evidence that the mortality during the last 140 years
 never was as high as in the most recent years.
description: The collection of the data is described in the article.
description: The data are stored in a zip-file. The data format of the
 individual files is csv-format. The read-me file is in
 md-format. 
description: The Data stored in the attached zip-file refer to the GCB-publication:
 "Climate-driven tree growth and mortality in the Black Forest,
 Germany—Long-term observations" by Heinrich Spiecker and Hans-Peter
 Kahle; first published: 08 August 2023;
 https://doi.org/10.1111/gcb.16897.The files contain the list of data used
 in each of the figures 2 to 7. File Spiecker-Kahle-2023-GCB-Figure-2.csv
 Climatic water balance during the growing season (May–September) of the
 current and the four preceding years (CWB) according to Thornthwaite and
 Mather (1955) in mm. The five highest-ranked years and the five
 lowest-ranked years are marked with blue or red figures, respectively.
 From 1881 to 2020 CWB shows a significant negative trend (dotted line).
 Missing value code: n/a. File Spiecker-Kahle-2023-GCB-Figure-3.csv Time
 series of climatic water balance during the growing season May–September
 of the current and the four preceding years 1950–2020 in mm (line, y-axis
 inverted) plotted together with the annual tree mortality (bars,
 1953–2020) over time. Tree mortality data for the years 2000–2004 are not
 included in this figure because of a severe storm event end of 1999.
 Missing value code: n/a. File Spiecker-Kahle-2023-GCB-Figure-4.csv Time
 series of observed mortality in % of the annual allowable cut (period
 1953–2020) and modeled mortality based on the 5-year moving average
 climatic water balance during the growing season (CWB, period from 1950 to
 2020; model M1). Observed mortality data for the years 2000–2001 are not
 included in this figure because of a severe storm event end of 1999.
 (Share of variance explained by model M1: 79.5%). Missing value code: n/a.
 File Spiecker-Kahle-2023-GCB-Figure-5.csv Time series of observed
 mortality in % of the annual allowable cut (period 1953–2020) and modeled
 mortality based on the annual radial growth rate index (RGR-index, period
 from 1950 to 2020, model M2; Further explanations see Figure 4; Share of
 variance explained by model M2: 56%). Missing value code: n/a. File
 Spiecker-Kahle-2023-GCB-Figure-6.csv Time series of observed annual radial
 growth rate index (RGR-index) and the modeled RGR-index based on the
 5-year moving average climatic water balance during the growing season
 (period 1900–2020, model G, R2?=?0.649, p?.001). Significant break point
 (bp) in variance of the observed RGR-index time series: 1987 (p?.05).
 Missing value code: n/a. File Spiecker-Kahle-2023-GCB-Figure-7.csv Time
 series of observed and modeled tree mortality over time. The observed
 mortality from 1953 to 2020 is presented in red bars (the years 2000–2001
 are not included because of a storm end of 1999). The blue bars describe
 the modeled mortality from 1881 to 2020 based on the climatic water
 balance (CWB, model M1) and the green bars describe the modeled mortality
 from 1900 to 2020 based on the annual radial growth rate index (RGR-index,
 model M2). Missing value code: n/a.