Dirnböck Thomas, Djukic Ika, Kitzler Barbara, Kobler Johannes, Mol-Dijkstra Janet P, Posch Max, Reinds Gert Jan, Schlutow Angela, Starlinger Franz, Wamelink Wieger G W
Department for Ecosystem Research and Environmental Information Management, Environment Agency Austria, Spittelauer Lände 5, Vienna, Austria.
Austrian Research Centre for Forests-BFW, Vienna, Austria.
PLoS One. 2017 Sep 12;12(9):e0184194. doi: 10.1371/journal.pone.0184194. eCollection 2017.
Climate change and excess deposition of airborne nitrogen (N) are among the main stressors to floristic biodiversity. One particular concern is the deterioration of valuable habitats such as those protected under the European Habitat Directive. In future, climate-driven shifts (and losses) in the species potential distribution, but also N driven nutrient enrichment may threaten these habitats. We applied a dynamic geochemical soil model (VSD+) together with a novel niche-based plant response model (PROPS) to 5 forest habitat types (18 forest sites) protected under the EU Directive in Austria. We assessed how future climate change and N deposition might affect habitat suitability, defined as the capacity of a site to host its typical plant species. Our evaluation indicates that climate change will be the main driver of a decrease in habitat suitability in the future in Austria. The expected climate change will increase the occurrence of thermophilic plant species while decreasing cold-tolerant species. In addition to these direct impacts, climate change scenarios caused an increase of the occurrence probability of oligotrophic species due to a higher N immobilisation in woody biomass leading to soil N depletion. As a consequence, climate change did offset eutrophication from N deposition, even when no further reduction in N emissions was assumed. Our results show that climate change may have positive side-effects in forest habitats when multiple drivers of change are considered.
气候变化和空气中氮（N）的过量沉降是植物多样性的主要压力源。一个特别令人担忧的问题是宝贵栖息地的退化，比如那些受《欧洲栖息地指令》保护的栖息地。未来，气候驱动的物种潜在分布变化（和损失）以及氮驱动的养分富集可能会威胁到这些栖息地。我们将一个动态地球化学土壤模型（VSD+）与一个基于生态位的新型植物响应模型（PROPS）应用于奥地利受欧盟指令保护的5种森林栖息地类型（18个森林地点）。我们评估了未来气候变化和氮沉降可能如何影响栖息地适宜性，栖息地适宜性被定义为一个地点容纳其典型植物物种的能力。我们的评估表明，气候变化将是未来奥地利栖息地适宜性下降的主要驱动因素。预期的气候变化将增加喜温植物物种的出现，同时减少耐寒物种。除了这些直接影响外，气候变化情景导致贫营养物种出现概率增加，因为木质生物量中氮的固定增加导致土壤氮耗竭。因此，即使假设氮排放量不再进一步减少，气候变化也确实抵消了氮沉降造成的富营养化。我们的结果表明，当考虑多种变化驱动因素时，气候变化可能在森林栖息地产生积极的副作用。
