Neuner S.,TU Munich |
Albrecht A.,Forest Research Institute Baden Wurttemberg |
Cullmann D.,Forest Research Institute Baden Wurttemberg |
Engels F.,Research Institute for Forest Ecology and Forestry Rhineland Palatinate FAWF |
And 8 more authors.
Global Change Biology | Year: 2015
Shifts in tree species distributions caused by climatic change are expected to cause severe losses in the economic value of European forestland. However, this projection disregards potential adaptation options such as tree species conversion, shorter production periods, or establishment of mixed species forests. The effect of tree species mixture has, as yet, not been quantitatively investigated for its potential to mitigate future increases in production risks. For the first time, we use survival time analysis to assess the effects of climate, species mixture and soil condition on survival probabilities for Norway spruce and European beech. Accelerated Failure Time (AFT) models based on an extensive dataset of almost 65 000 trees from the European Forest Damage Survey (FDS) - part of the European-wide Level I monitoring network - predicted a 24% decrease in survival probability for Norway spruce in pure stands at age 120 when unfavorable changes in climate conditions were assumed. Increasing species admixture greatly reduced the negative effects of unfavorable climate conditions, resulting in a decline in survival probabilities of only 7%. We conclude that future studies of forest management under climate change as well as forest policy measures need to take this, as yet unconsidered, strongly advantageous effect of tree species mixture into account. © 2014 John Wiley & Sons Ltd.
Stark H.,Albert Ludwigs University of Freiburg |
Nothdurft A.,University of Natural Resources and Life Sciences, Vienna |
Block J.,Research Institute for Forest Ecology and Forestry Rhineland Palatinate FAWF |
Bauhus J.,Albert Ludwigs University of Freiburg
Forest Ecology and Management | Year: 2015
The rapid re-establishment of forests following large disturbances is being seen as one option to increase the contribution of forests to climate change mitigation. The temporary inclusion of pioneer trees as nurse crops on disturbed sites can facilitate the establishment of target tree species and may additionally benefit productivity and soil fertility. In this study we compared productivity and nutrient cycling between stands of oak target species (Quercus robur and Quercus petraea) that were established with and without widely spaced Betula ssp. or Populus ssp. nurse crops. Simulation results for a full rotation of oaks (180years) indicated that both types of forests, with and without nurse crops, have a comparable total productivity. However, stands with nurse crops supplied 59-96Mgha-1 harvestable biomass after 20years, whereas the first harvest of biomass from stands without nurse crops would occur at least 30years later. Nutrient element costs associated with the removal of Betula ssp. wood were low compared to Populus ssp. Also, nurse crop stands had up to 2.5 times larger pools of exchangeable base cations in top mineral soils (0-30cm) compared to mono-specific oak stands. The high soil cation pools may have resulted from reduced leaching under nurse crops or the increased recycling of cations, also from deeper soil depth, via litter fall and fine-root turnover. Our results show that forest reestablishment with pioneer tree species may be a suitable tool for the rapid recovery of forest productivity and mitigation potential following disturbances while simultaneously helping to maintain or increase soil fertility. © 2014 Elsevier B.V.