Modelling study of soil C, N and pH response to air pollution and climate change using European LTER site observations

Abstract

Current climate warming is expected to continue in coming decades, whereas high N deposition may stabilize, in contrast to the clear decrease in S deposition. These pressures have distinctive regional patterns and their resulting impact on soil conditions is modified by local site characteristics. We have applied the VSD+ soil dynamic model to study impacts of deposition and climate change on soil properties, using MetHyd and GrowUp as pre-processors to provide input to VSD+. The single-layer soil model VSD+ accounts for processes of organic C and N turnover, as well as charge and mass balances of elements, cation exchange and base cation weathering. We calibrated VSD+ at 26 ecosystem study sites throughout Europe using observed conditions, and simulated key soil properties: soil solution pH (pH), soil base saturation (BS) and soil organic carbon and nitrogen ratio (C:N) under projected deposition of N and S, and climate warming until 2100. The sites are forested, located in the Mediterranean, forested alpine, Atlantic, continental and boreal regions. They represent the long-term ecological research (LTER) Europe network, including sites of the ICP Forests and ICP Integrated Monitoring (IM) programmes under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP), providing high quality long-term data on ecosystem response. Simulated future soil conditions improved under projected decrease in deposition and current climate conditions: higher pH, BS and C:N at 21, 16 and 12 of the sites, respectively. When climate change was included in the scenario analysis, the variability of the results increased. Climate warming resulted in higher simulated pH in most cases, and higher BS and C:N in roughly half of the cases. Especially the increase in C:N was more marked with climate warming. The study illustrates the value of LTER sites for applying models to predict soil responses to multiple environmental changes.

A Climate Service for Ecologists: Sharing pre-processed EUROCORDEX Regional Climate Scenario Data using the eLTER Information System

“…In Dirnbock et al (2018) the site-based regional climate change scenario and deposition data were used in connection with a dynamic soil model coupled to a statistical plant species niche model to explore expected plant response to legislated reductions in nitrogen emissions. Holmberg et al (2018) looked at the impacts of deposition and climate change on soil conditions, using the regional climate change scenario data to explore long-term ecosystem impacts.…”

“…Regional climate models have a number of advantages over global climate models in reproducing regional features of the 290 climate system and producing data for applications (Giorgi 2019;Rummukainen, 2016). Regional climate change impacts on ecosystem functioning or services are highly relevant for the eLTER network (Diffenbaugh and Field, 2013;Nolan et al, 2018;Hoegh-Guldberg et al, 2019;Runting et al, 2017;Holmberg et al, 2018;Dirnboeck et al, 2018). To make specific use of climate change information across sectors and help distil the ever increasing data volumes from climate models (e.g., Overpeck 2011) climate services (Hewitt et al, 2012) have evolved, which can be classified into different types (Visscher et al, 2020).…”

Spatially Resolved Soil Solution Chemistry in a Central European Atmospherically Polluted High-Elevation Catchment

“…The BS at UDL was twice larger than the BS in similar soil depths in the leucogranitic catchment LYS [20][21], which is the most acidified catchment of the Czech monitoring network [9]. Holmberg et al [22] evaluated BS and CEC of numerous forest sites of the LTER (Long-Term Ecological Research) network in nine European countries, with calculated median BS of 30 % and CEC of 84 meq kg -1 . From the European perspective, the soil BS and CEC values at the UDL were low.…”

Currently legislated decreases in nitrogen deposition will yield only limited plant species recovery in European forests

“…The plots are located in Atlantic, continental, Mediterranean, alpine and boreal regions in 10 countries across Europe and cover major continental N pollution and climate gradients (figure 1, S1 table 1 is available online at stacks.iop.org/ERL/13/125010/ mmedia). Our assessment was based on a previous model calibration study using the same sites as Holmberg et al (2018), where a detailed description of the climate and soil input parameters for the soil model VSD+ can be found.…”

“…VSD+is driven by time series of N and S deposition as well as temperature and hydrology to predict soil solution chemistry and soil C and N pools. The VSD+calibration was taken from Holmberg et al (2018) apart for AT02 where the model was calibrated using an identical procedure. The start year of the model runs was set to 1971.…”