• CONTEXT : Projecting changes in forest productivity in Europe is crucial for adapting forest management to changing environmental conditions. • AIMS : The objective of this paper is to project ...forest productivity changes under different climate change scenarios at a large number of sites in Europe with a stand-scale process-based model. • METHODS : We applied the process-based forest growth model 4C at 132 typical forest sites of important European tree species in ten environmental zones using climate change scenarios from three different climate models and two different assumptions about CO₂ effects on productivity. • RESULTS : This paper shows that future forest productivity will be affected by climate change and that these effects depend strongly on the climate scenario used and the persistence of CO₂ effects. We find that productivity increases in Northern Europe, increases or decreases in Central Europe, and decreases in Southern Europe. This geographical pattern is mirrored by the responses of the individual tree species. The productivity of Scots pine and Norway spruce, mostly located in central and northern Europe, increases while the productivity of Common beech and oak in southern regions decreases. It is important to note that we consider the physiological response to climate change excluding disturbances or management. • CONCLUSIONS : Different climate change scenarios and assumptions about the persistence of CO₂ effects lead to uncertain projections of future forest productivity. These uncertainties need to be integrated into forest management planning and adaptation of forest management to climate change using adaptive management frameworks.
Germany's forests provide a variety of ecosystem services. Sustainable forest management aims to optimize the provision of these services at regional level. However, climate change will impact forest ...ecosystems and subsequently ecosystem services. The objective of this study is to quantify the effects of two alternative management scenarios and climate impacts on forest variables indicative of ecosystem services related to timber, habitat, water, and carbon. The ecosystem services are represented through nine model output variables (timber harvest, above and belowground biomass, net ecosystem production, soil carbon, percolation, nitrogen leaching, deadwood, tree dimension, broadleaf tree proportion) from the process-based forest model 4C. We simulated forest growth, carbon and water cycling until 2045 with 4C set-up for the whole German forest area based on National Forest Inventory data and driven by three management strategies (nature protection, biomass production and a baseline management) and an ensemble of regional climate scenarios (RCP2.6, RCP 4.5, RCP 8.5). We provide results as relative changes compared to the baseline management and observed climate. Forest management measures have the strongest effects on ecosystem services inducing positive or negative changes of up to 40% depending on the ecosystem service in question, whereas climate change only slightly alters ecosystem services averaged over the whole forest area. The ecosystem services 'carbon' and 'timber' benefit from climate change, while 'water' and 'habitat' lose. We detect clear trade-offs between 'timber' and all other ecosystem services, as well as synergies between 'habitat' and 'carbon'. When evaluating all ecosystem services simultaneously, our results reveal certain interrelations between climate and management scenarios. North-eastern and western forest regions are more suitable to provide timber (while minimizing the negative impacts on remaining ecosystem services) whereas southern and central forest regions are more suitable to fulfil 'habitat' and 'carbon' services. The results provide the base for future forest management optimizations at the regional scale in order to maximize ecosystem services and forest ecosystem sustainability at the national scale.
Understanding the processes that shape forest functioning, structure, and diversity remains challenging, although data on forest systems are being collected at a rapid pace and across scales. Forest ...models have a long history in bridging data with ecological knowledge and can simulate forest dynamics over spatio‐temporal scales unreachable by most empirical investigations.
We describe the development that different forest modelling communities have followed to underpin the leverage that simulation models offer for advancing our understanding of forest ecosystems.
Using three widely applied but contrasting approaches – species distribution models, individual‐based forest models, and dynamic global vegetation models – as examples, we show how scientific and technical advances have led models to transgress their initial objectives and limitations. We provide an overview of recent model applications on current important ecological topics and pinpoint ten key questions that could, and should, be tackled with forest models in the next decade.
Synthesis. This overview shows that forest models, due to their complementarity and mutual enrichment, represent an invaluable toolkit to address a wide range of fundamental and applied ecological questions, hence fostering a deeper understanding of forest dynamics in the context of global change.
Forest models can help understanding the processes that shape forest functioning, structure and diversity, since they can can simulate forest dynamics over spatio‐temporal scales unreachable by most empirical investigations. Here we describe the development of three widely applied but contrasting forest mo−delling approaches — species distribution models, individual‐based models and dynamic global vegetation models. We provide an overview of recent model applications and pinpoint ten key questions that could, and should, be tackled with forest models in the next decade.
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 on European forests 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, and 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.2020.006/; Reyer et al., 2020). 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://CRAN.R-project.org/package=ProfoundData; Silveyra
Gonzalez et al., 2020), which provides basic functions to explore, plot and
extract the data for model set-up, calibration and evaluation.
Ecology and forestry sciences are using an increasing amount of data to address a wide variety of technical and research questions at the local, continental and global scales. However, one type of ...data remains rare: fine-grain descriptions of large landscapes. Yet, this type of data could help address the scaling issues in ecology and could prove useful for testing forest management strategies and accurately predicting the dynamics of ecosystem services. Here we present three datasets describing three large European landscapes in France, Poland and Slovenia down to the tree level. Tree diameter, height and species data were generated combining field data, vegetation maps and airborne laser scanning (ALS) data following an area-based approach. Together, these landscapes cover more than 100 000 ha and consist of more than 42 million trees of 51 different species. Alongside the data, we provide here a simple method to produce high-resolution descriptions of large landscapes using increasingly available data: inventory and ALS data. We carried out an in-depth evaluation of our workflow including, among other analyses, a leave-one-out cross validation. Overall, the landscapes we generated are in good agreement with the landscapes they aim to reproduce. In the most favourable conditions, the root mean square error (RMSE) of stand basal area (BA) and mean quadratic diameter (Dg) predictions were respectively 5.4 m
.ha
and 3.9 cm, and the generated main species corresponded to the observed main species in 76.2% of cases.
The offshore industry operates increasingly large installations in exposed areas requiring high reliability and availability. Downtime of complex offshore systems leads to significant financial ...losses. Towards year-round offshore installation and maintenance service, this research focuses on the identification of weather-robust vessel designs. Even though it might seem that the motions of a larger vessel will be more favorable than those of a smaller vessel, this research shows that this hypothesis is not necessarily true. It will be shown that for certain vessel parameters the performance of a larger vessel is not better than that of a smaller vessel. This investigation aims to provide knowledge for a more holistic vessel design optimization approach to enable ship designers and operators to design and select an offshore vessel with main dimensions and hydrostatic parameters providing optimal seakeeping performance for a given operation and environment. The key aspect is a mission-dependent optimization of hull dimensions, including loading condition parameters, aiming for a hull design where natural periods of important responses such as pitch and roll are significantly distinct from the dominating wave periods. For this purpose, a novel parameter for seakeeping performance evaluation, the Operability Robustness Index (ORI), will be used.
•Vessel size is not necessarily decisive for the assessment of seakeeping performance.•Identification of potential for performance improvement during the design process.•The ORI indicates advantages for design optimization during the ship design process.•The ORI is a more robust KPI than percentage operability.
To assess how the effects of drought could be better captured in process-based models, this study simulated and contrasted two water uptake approaches in Scots pine and Scots pine-Sessile oak stands. ...The first approach consisted of an empirical function for root water uptake (WU1). The second approach was based on differences of soil water potential along a soil-plant-atmosphere continuum (WU2) with total root resistance varying at low, medium and high total root resistance levels. Three data sets on different time scales relevant for tree growth were used for model evaluation: Two short-term datasets on daily transpiration and soil water content as well as a long-term dataset on annual tree ring increments. Except WU2 with high total root resistance, all transpiration outputs exceeded observed values. The strongest correlation between simulated and observed annual tree ring width occurred with WU2 and high total root resistance. The findings highlighted the importance of severe drought as a main reason for small diameter increment. However, if all three data sets were taken into account, no approach was superior to the other. We conclude that accurate projections of future forest productivity depend largely on the realistic representation of root water uptake in forest model simulations.
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