Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?
In a recent paper published in Environmental Reserach Letters we - together with a large European consortium - investigate the interactive effects between forest productivity and disturbance.
Many studies suggest an increase in productivity in Europe’s forests for the coming decades (Reyer et al. 2014). Mechanisms behind this expected increase are extended growing seasons due to climate change, the effect of CO2 fertilization, as well as the added nitrogen input due to human emissions. However, at the same time disturbances are increasing (Seidl et al. 2014), and the increase in disturbances has been hypothesized to be responsible for a decreasing carbon uptake of forests from the atmosphere in recent years (Nabuurs et al. 2013). Here we – together with a large group of European researchers from the MOTIVE project and the COST action PROFOUND – investigated how increasing disturbances interact with productivity changes across Europe’s forest ecosystems.
Our results show that in most case studies across Europe increasing disturbances due to climate change can reduce or even cancel out productivity increases, or exacerbate climate-induced productivity declines (e.g., due to drought). In a few selected case studies, however, disturbances also showed a positive effect on productivity, e.g., where low severity disturbances alleviate resource competition (see also Silva Pedro 2016). Our findings underline the importance to consider the effects of climate change on all processes of forest dynamics interactively.