The PROFOUND database for evaluating vegetation models and simulating climate impacts on forests

Abstract

Abstract. Process-based vegetation models are widely used to predict local and global ecosystem dynamics and climate change impacts. Due to their complexity, they require careful parameterization and evaluation to ensure that projections are accurate and reliable. The PROFOUND Database (PROFOUND DB) provides a wide range of empirical data to calibrate and evaluate vegetation models that simulate climate impacts at the forest stand scale. A particular advantage of this database is its wide coverage of multiple data sources at different hierarchical and temporal scales, together with environmental driving data as well as the latest climate scenarios. Specifically, the PROFOUND DB provides general site descriptions, soil, climate, CO2, nitrogen deposition, tree and forest stand-level, as well as remote sensing data for nine contrasting forest stands distributed across Europe. Moreover, for a subset of five sites, time series of carbon fluxes, atmospheric heat conduction, and soil water are also available. The climate and nitrogen deposition data contain several datasets for the historic period and a wide range of future climate change scenarios following the Representative Concentration Pathways (RCP2.6, RCP4.5, RCP6.0, RCP8.5). We also provide pre-industrial climate simulations that allow for model runs aimed at disentangling the contribution of climate change to observed forest productivity changes. The PROFOUND DB is available freely as a SQLite relational database or ASCII flat file version (at https://doi.org/10.5880/PIK.2019.008). The data policies of the individual, contributing datasets are provided in the metadata of each data file. The PROFOUND DB can also be accessed via the ProfoundData R-package (https://github.com/COST-FP1304-PROFOUND/ProfoundData), which provides basic functions to explore, plot, and extract the data for model set-up, calibration and evaluation.

Capturing ecological processes in dynamic forest models: why there is no silver bullet to cope with complexity

“…Furthermore, we derived alternative formulations, most of which were able to resolve deficiencies in model behavior without significantly increasing the model’s complexity. In particular, our results demonstrate the huge potential of large datasets (e.g., International Tree‐Ring Data Bank [ITRDB] or PROFOUND database; Reyer et al 2019) for refining process‐based formulations that have been partly developed completely data free into data‐informed process‐based formulations while achieving a better understanding of the nature of the core processes underlying long‐term forest dynamics.…”

“…For the short‐term managed simulations, we used seven sites featuring managed and predominantly even‐aged planted forests of the PROFOUND reference dataset (Reyer et al 2019; Fig. 4; Appendix : Table S6), which provides harmonized climate, soil, and forest inventory data.…”

“…We defined two sets of values, depending on the exogenous disturbance regime: For basal area (BA7), the share of giant trees (BATrs80), and the minimum age of trees of the mature timber stage (MinAge50), the ranges of values were assumed to be higher for the old‐growth (no major landscape‐level disturbances) than the shifting‐mosaic applications, while for tree numbers (Trs and Trs7), it was vice versa. For the short‐term managed application, inventory data were used for benchmarking (see Appendix : Table S6; Reyer et al 2019).…”

Net carbon ecosystem exchange during 24 years in the Sorø Beech Forest – relations to phenology and climate

“…When easterly winds dominate, they result in cold winters and hot summers. The average annual temperature during the period 1996-2010 was 9 C and the average annual precipitation during the same period was 640 mm (Reyer et al, 2019).…”

“…The average tree diameter at breast height (DBH) ranged from 4.7 cm in 1944 to 38.8 cm in 2010, and the stand density from 1767 to 288 stems ha À1 over the same time-span (Reyer et al, 2019). The wood increment calculated on the basis of yield tables (Møller, 1933) was approximately 11 m 3 ha À1 yr À1.…”