FORests and HYdrology under Climate Change in Switzerland v1.0: a spatially distributed model combining hydrology and forest dynamics
<p>We present FORHYCS (FORests and HYdrology under Climate Change in Switzerland), a distributed ecohydrological model to assess the impact of climate change on water resources and forest dynamics. FORHYCS is based on the coupling of the hydrological model PREVAH and the forest landscape model...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2020-02-01
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| Series: | Geoscientific Model Development |
| Online Access: | https://www.geosci-model-dev.net/13/537/2020/gmd-13-537-2020.pdf |
| _version_ | 1818996895937200128 |
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| author | M. J. R. Speich M. J. R. Speich M. J. R. Speich M. J. R. Speich M. J. R. Speich M. Zappa M. Scherstjanoi M. Scherstjanoi H. Lischke |
| author_facet | M. J. R. Speich M. J. R. Speich M. J. R. Speich M. J. R. Speich M. J. R. Speich M. Zappa M. Scherstjanoi M. Scherstjanoi H. Lischke |
| author_sort | M. J. R. Speich |
| collection | DOAJ |
| description | <p>We present FORHYCS (FORests and HYdrology under Climate Change in Switzerland), a distributed ecohydrological model to assess the impact of climate change on water resources and forest dynamics. FORHYCS is based on the coupling of the hydrological model PREVAH and the forest landscape model TreeMig. In a coupled simulation, both original models are executed simultaneously and exchange information through shared variables. The simulated canopy structure is summarized by the leaf area index (LAI), which affects local water balance calculations. On the other hand, an annual drought index is obtained from daily simulated potential and actual transpiration. This drought index affects tree growth and mortality, as well as a species-specific tree height limitation. The effective rooting depth is simulated as a function of climate, soil, and simulated above-ground vegetation structure. Other interface variables include stomatal resistance and leaf phenology.</p>
<p>Case study simulations with the model were performed in the Navizence catchment in the Swiss Central Alps, with a sharp elevational gradient and climatic conditions ranging from dry inner-alpine to high alpine. In a first experiment, the model was run for 500 years with different configurations. The results were compared against observations of vegetation properties from national forest inventories, remotely sensed LAI, and high-resolution canopy height maps from stereo aerial images. Two new metrics are proposed for a quantitative comparison of observed and simulated canopy structure. In a second experiment, the model was run for 130 years under climate change scenarios using both idealized temperature and precipitation change and meteorological forcing from downscaled GCM-RCM model chains.</p>
<p>The first experiment showed that model configuration greatly influences simulated vegetation structure. In particular, simulations where height limitation was dependent on environmental stress showed a much better fit to canopy height observations. Spatial patterns of simulated LAI were more realistic than for uncoupled simulations of the forest landscape model, although some model deficiencies are still evident. Under idealized climate change scenarios, the effect of the coupling varied regionally, with the greatest effects on simulated streamflow (up to 60 mm yr<span class="inline-formula"><sup>−1</sup></span> difference with respect to a simulation with static vegetation parameters) seen at the valley bottom and in regions currently above the treeline. This case study shows the importance of coupling hydrology and vegetation dynamics to simulate the impact of climate change on ecosystems. Nevertheless, it also highlights some challenges of ecohydrological modeling, such as the need to realistically simulate the plant response to increased <span class="inline-formula">CO<sub>2</sub></span> concentrations and process uncertainty regarding future land cover changes.</p> |
| first_indexed | 2024-12-20T21:37:01Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 1991-959X 1991-9603 |
| language | English |
| last_indexed | 2024-12-20T21:37:01Z |
| publishDate | 2020-02-01 |
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| series | Geoscientific Model Development |
| spelling | doaj.art-8e9028fda03b4be58343688562f54bd42022-12-21T19:25:55ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032020-02-011353756410.5194/gmd-13-537-2020FORests and HYdrology under Climate Change in Switzerland v1.0: a spatially distributed model combining hydrology and forest dynamicsM. J. R. Speich0M. J. R. Speich1M. J. R. Speich2M. J. R. Speich3M. J. R. Speich4M. Zappa5M. Scherstjanoi6M. Scherstjanoi7H. Lischke8Dynamic Macroecology, Swiss Federal Research Institute WSL, 8903 Birmensdorf, SwitzerlandHydrological Forecasts, Swiss Federal Research Institute WSL, 8903 Birmensdorf, SwitzerlandDepartment of Environmental Systems Science, ETH Zurich, 8092 Zurich, SwitzerlandBiometry and Environmental Systems Analysis, University of Freiburg, 79085 Freiburg im Briesgau, GermanyInstitute of Sustainable Development, Zurich University of Applied Sciences (ZHAW), 8401 Winterthur, SwitzerlandHydrological Forecasts, Swiss Federal Research Institute WSL, 8903 Birmensdorf, SwitzerlandDynamic Macroecology, Swiss Federal Research Institute WSL, 8903 Birmensdorf, SwitzerlandInstitute of Climate-Smart Agriculture, Johann Heinrich von Thünen Institute, 38116 Braunschweig, GermanyDynamic Macroecology, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland<p>We present FORHYCS (FORests and HYdrology under Climate Change in Switzerland), a distributed ecohydrological model to assess the impact of climate change on water resources and forest dynamics. FORHYCS is based on the coupling of the hydrological model PREVAH and the forest landscape model TreeMig. In a coupled simulation, both original models are executed simultaneously and exchange information through shared variables. The simulated canopy structure is summarized by the leaf area index (LAI), which affects local water balance calculations. On the other hand, an annual drought index is obtained from daily simulated potential and actual transpiration. This drought index affects tree growth and mortality, as well as a species-specific tree height limitation. The effective rooting depth is simulated as a function of climate, soil, and simulated above-ground vegetation structure. Other interface variables include stomatal resistance and leaf phenology.</p> <p>Case study simulations with the model were performed in the Navizence catchment in the Swiss Central Alps, with a sharp elevational gradient and climatic conditions ranging from dry inner-alpine to high alpine. In a first experiment, the model was run for 500 years with different configurations. The results were compared against observations of vegetation properties from national forest inventories, remotely sensed LAI, and high-resolution canopy height maps from stereo aerial images. Two new metrics are proposed for a quantitative comparison of observed and simulated canopy structure. In a second experiment, the model was run for 130 years under climate change scenarios using both idealized temperature and precipitation change and meteorological forcing from downscaled GCM-RCM model chains.</p> <p>The first experiment showed that model configuration greatly influences simulated vegetation structure. In particular, simulations where height limitation was dependent on environmental stress showed a much better fit to canopy height observations. Spatial patterns of simulated LAI were more realistic than for uncoupled simulations of the forest landscape model, although some model deficiencies are still evident. Under idealized climate change scenarios, the effect of the coupling varied regionally, with the greatest effects on simulated streamflow (up to 60 mm yr<span class="inline-formula"><sup>−1</sup></span> difference with respect to a simulation with static vegetation parameters) seen at the valley bottom and in regions currently above the treeline. This case study shows the importance of coupling hydrology and vegetation dynamics to simulate the impact of climate change on ecosystems. Nevertheless, it also highlights some challenges of ecohydrological modeling, such as the need to realistically simulate the plant response to increased <span class="inline-formula">CO<sub>2</sub></span> concentrations and process uncertainty regarding future land cover changes.</p>https://www.geosci-model-dev.net/13/537/2020/gmd-13-537-2020.pdf |
| spellingShingle | M. J. R. Speich M. J. R. Speich M. J. R. Speich M. J. R. Speich M. J. R. Speich M. Zappa M. Scherstjanoi M. Scherstjanoi H. Lischke FORests and HYdrology under Climate Change in Switzerland v1.0: a spatially distributed model combining hydrology and forest dynamics Geoscientific Model Development |
| title | FORests and HYdrology under Climate Change in Switzerland v1.0: a spatially distributed model combining hydrology and forest dynamics |
| title_full | FORests and HYdrology under Climate Change in Switzerland v1.0: a spatially distributed model combining hydrology and forest dynamics |
| title_fullStr | FORests and HYdrology under Climate Change in Switzerland v1.0: a spatially distributed model combining hydrology and forest dynamics |
| title_full_unstemmed | FORests and HYdrology under Climate Change in Switzerland v1.0: a spatially distributed model combining hydrology and forest dynamics |
| title_short | FORests and HYdrology under Climate Change in Switzerland v1.0: a spatially distributed model combining hydrology and forest dynamics |
| title_sort | forests and hydrology under climate change in switzerland v1 0 a spatially distributed model combining hydrology and forest dynamics |
| url | https://www.geosci-model-dev.net/13/537/2020/gmd-13-537-2020.pdf |
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