@article{HeinrichsAmmerMundetal.2019,
  author    = {Heinrichs, Steffi and Ammer, Christian and Mund, Martina and Boch, Steffen and Budde, Sabine and Fischer, Markus and Mueller, Joerg and Schoening, Ingo and Schulze, Ernst-Detlef and Schmidt, Wolfgang and Weckesser, Martin and Schall, Peter},
  title     = {Landscape-Scale Mixtures of Tree Species are More Effective than Stand-Scale Mixtures for Biodiversity of Vascular Plants, Bryophytes and Lichens},
  series = {Forests},
  volume    = {10},
  journal   = {Forests},
  number    = {1},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1999-4907},
  doi       = {10.3390/f10010073},
  pages     = {34},
  year      = {2019},
  abstract  = {Tree species diversity can positively affect the multifunctionality of forests. This is why conifer monocultures of Scots pine and Norway spruce, widely promoted in Central Europe since the 18th and 19th century, are currently converted into mixed stands with naturally dominant European beech. Biodiversity is expected to benefit from these mixtures compared to pure conifer stands due to increased abiotic and biotic resource heterogeneity. Evidence for this assumption is, however, largely lacking. Here, we investigated the diversity of vascular plants, bryophytes and lichens at the plot (alpha diversity) and at the landscape (gamma diversity) level in pure and mixed stands of European beech and conifer species (Scots pine, Norway spruce, Douglas fir) in four regions in Germany. We aimed to identify compositions of pure and mixed stands in a hypothetical forest landscape that can optimize gamma diversity of vascular plants, bryophytes and lichens within regions. Results show that gamma diversity of the investigated groups is highest when a landscape comprises different pure stands rather than tree species mixtures at the stand scale. Species mainly associated with conifers rely on light regimes that are only provided in pure conifer forests, whereas mixtures of beech and conifers are more similar to beech stands. Combining pure beech and pure conifer stands at the landscape scale can increase landscape level biodiversity and conserve species assemblages of both stand types, while landscapes solely composed of stand scale tree species mixtures could lead to a biodiversity reduction of a combination of investigated groups of 7 up to 20\%.},
  language  = {en}
}
@article{LeuschnerWulfBaeuchleretal.2014,
  author    = {Leuschner, Christoph and Wulf, Monika and Baeuchler, Patricia and Hertel, Dietrich},
  title     = {Forest continuity as a key determinant of soil carbon and nutrient storage in beech forests on sandy soils in Northern Germany},
  series = {Ecosystems},
  volume    = {17},
  journal   = {Ecosystems},
  number    = {3},
  publisher = {Springer},
  address   = {New York},
  issn      = {1432-9840},
  doi       = {10.1007/s10021-013-9738-0},
  pages     = {497 -- 511},
  year      = {2014},
  abstract  = {Forest (or tree) age has been identified as an important determinant of the carbon (C) storage potential of forest soils. A large part of Central Europe's current forested area was affected by land use change with long periods of cultivation in past centuries suggesting that the organic C stocks in the soil (SOC) under recent forest may partly be legacies of the past and that stand age effects have to be distinguished from forest continuity effects (that is, the time since re-afforestation). We examined the influence of mean tree age and forest continuity on the SOC pool and the stores of total N and available P, Ca, Mg, and K in the soil (mineral soil and organic layer) across a sample of 14 beech (Fagus sylvatica) forests on sandy soil with variable tree age (23-189 years) and forest continuity (50-year-old afforestation to ancient ('permanent') forest, that is, > 230 years of proven continuity). Ancient beech forests (> 230 years of continuity) stored on average 47 and 44\% more organic C and total N in the soil than recent beech afforestation (50-128 years of continuity). Contrary to expectation, we found large and significant C and N pool differences between the forest categories in the mineral soil but not in the organic layer indicating that decade- or century-long cultivation has reduced the subsoil C and nutrient stores while the organic layer element pools have approached a new equilibrium after only 50-128 years. PCA and correlation analyses suggest that forest continuity cannot be ignored when trying to understand the variation in soil C stocks between different stands. Forest clearing, subsequent cultivation, and eventual re-afforestation with beech resulted in similar relative stock reductions of C and N and, thus, no change in soil C/N ratio. We conclude that the continuity of forest cover, which may or may not be related to tree age, is a key determinant of the soil C and nutrient stores of beech forests in the old cultural landscape of Central Europe.},
  language  = {en}
}
@article{LeuschnerWulfBaeuchleretal.2013,
  author    = {Leuschner, Christoph and Wulf, Monika and B{\"a}uchler, Patricia and Hertel, Dietrich},
  title     = {Soil C and nutrient stores under Scots pine afforestations compared to ancient beech forests in the German Pleistocene - the role of tree species and forest history},
  series = {Forest ecology and management},
  volume    = {310},
  journal   = {Forest ecology and management},
  number    = {6},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0378-1127},
  doi       = {10.1016/j.foreco.2013.08.043},
  pages     = {405 -- 415},
  year      = {2013},
  abstract  = {In the diluvial lowlands of northern Germany, the Netherlands and northern Poland, an estimated similar to 5 Mio ha of Scots pine plantations (Pinus sylvestris) has been established on sandy soil in the last 250 years replacing the former temperate broad-leaved forests after extended periods of cultivation in the Middle Ages. We examined the effect of variable stand continuity of pine plantations (recent vs. ancient: 51-128 vs. >230 years) on the soil organic carbon (SOC) store and soil nutrient capital in comparison to ancient beech forests (>230 years of continuity) which represent the potential natural forest vegetation. Recent and ancient pine stands had c. 75\% larger organic layer C stores than ancient beech forests, while the total C stock in the soil (organic layer and mineral soil to 100 cm) was similar to 25\% larger in the beech forests due to higher C concentrations in 0-50 cm depth of the mineral soil. The soil stores of N-tot were similar to 50\% and the exchangeable Ca, K and Mg pools about three times larger under beech than under the pine stands. Resin-exchangeable P was enriched in the soils under ancient pine stands probably due to manuring in the past. After clear-cut and long cultivation, it may take >230 years of forest presence to restore the greatly reduced mineral soil C and N pools. The C and N sequestration potential of the soils appeared to be particularly small under pine indicating a pronounced tree species (pine vs. beech) effect on soil C and N dynamics. We conclude that, in the face of rising greenhouse gas emissions, the limited soil C and nutrient storage potential of Scots pine plantations on sandy soils needs consideration when selecting suitable tree species for future forestry. (C) 2013 Elsevier B.V. All rights reserved.},
  language  = {en}
}