Use of dynamic soil–vegetation models to assess impacts of nitrogen deposition on plant species composition: an overview

Abstract

This version available http://nora.nerc.ac.uk/8737/ NERC has developed NORA to enable users to access research outputs wholly or partially funded by NERC. Copyright and other rights for material on this site are retained by the authors and/or other rights owners. Users should read the terms and conditions of use of this material at http://nora.nerc.ac.uk/policies.html#access This document is the author's final manuscript version of the journal article, incorporating any revisions agreed during the peer review process. Some differences between this and the publisher's version remain. You are advised to consult the publisher's version if you wish to cite from this article. www.esajournals.orgContact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trade marks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. Field observations and experimental data of effects of nitrogen (N) deposition on plant species 2 diversity have been used to derive empirical critical N loads for various ecosystems. The great 3 advantage of such as approach is the inclusion of field evidence, but there are also restrictions, 4 such as the absence of explicit criteria regarding significant effects on the vegetation, and the 5 impossibility to predict future impacts when N deposition changes. Model approaches can account 6 for this. In this paper, we review the possibilities of static and dynamic multi-species models in 7 combination with dynamic soil -vegetation models to (i) predict plant species composition as a 8 function of atmospheric N deposition and (ii) calculate critical N loads in relation to a prescribed 9 protection level of the species composition. The similarities between the models are presented, but 10 also several important differences, including the use of different indicators for N and acidity and 11 the prediction of individual plant species versus plant communities. A summary of the strengths 12 and weaknesses of the various models, including their validation status, is given. Furthermore, 13 examples are given of critical load calculations with the model chains and their comparison with 14 empirical critical N loads. We show that linked biogeochemistry-biodiversity models for N have 15 potential for applications to support European policy to reduce N input, but the definition of 16 damage thresholds for terrestrial biodiversity represents a major challenge. There is a also a clear 17 need for further testing and validation of the models against long-term monitoring or long-term 18 experimental datasets and against large-scale survey data. This requires a focused data collection in 19Europe, combing vegetation descriptions with variables affecting the species diversity, such as soil 20 acidity, nutrient status and water availability. Finally, there is a need for adaptation and upscaling of 21 the models beyond the regions for which dose-response relationships have been parameterised, to 22 make them ...

Global assessment of nitrogen deposition effects on terrestrial plant diversity: a synthesis

“…2 and 3, are thus a significant step forward and essential to demonstrate that reduction of atmospheric N deposition is needed to protect this richness. These results and the modeling studies discussed in the companion paper (De Vries et al 2010) are, however, presently difficult to generalize across all biomes outside Europe and North America. Efforts in the near future are required to extend evaluations of effect thresholds to low-latitude ecosystems, which are now (or will be in the coming decades) under threats of increasing N deposition (Figs.…”

“…Therefore, for a prognosis of the long-term response of ecosystems to deposition, climate, and management scenarios, an approach based on dynamic models is needed. Recently, integrated dynamic soil-vegetation modeling approaches have been developed to assess the impacts of N deposition on plant species diversity for specific ecosystems (De Vries et al 2010). Such dynamic models have a strong mechanistic basis, and hence can provide a stronger scientific basis for policy assessment in the future.…”

Combined effect of atmospheric nitrogen deposition and climate change on temperate forest soil biogeochemistry: A modeling approach

“…However, this modeling approach is steady state, i.e., it relies on the ecosystem having a sustainable state. Dynamic biogeochemical models have been developed to include time trends and changes (see De Vries et al, 2010 for an overview of the existing models). This is particularly important for testing different scenarios of atmospheric N deposition that, by definition, change over time.…”

Effects of nitrogen deposition and empirical nitrogen critical loads for ecoregions of the United States

“…There are three main approaches for estimating critical loads (Pardo 2010): empirical, steady-state mass balance (UBA 2004), and dynamic modeling (Slootweg et al 2007, de Vries et al 2010. Empirical critical loads are determined from observations of detrimental responses of an ecosystem or ecosystem component to an observed N deposition input (Pardo 2010).…”