@book{RolfesWeithAehneltetal.2005,
  author    = {Rolfes, Manfred and Weith, Thomas and Aehnelt, Reinhard and Schreiber, Karsten and Schultz, Heiko and Werth, Manfred and Neumann, Uwe and Wilhelm, Jan Lorenz and Jessel, Beate and Herberg, Alfred and Kaether, Johann and Zillmer, Sabine and Wiechmann, Thorsten},
  title     = {Evaluation in der Praxis: : Aktuelle Beispiele aus der Stadt-, Regional- und Umweltentwicklung},
  editor    = {Rolfes, Manfred and Weith, Thomas},
  isbn      = {978-3-937786-50-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53069},
  publisher      = {Universit{\"a}t Potsdam},
  year      = {2005},
  language  = {de}
}
@article{NeumannCoselZimmermannHalletal.2011,
  author    = {Neumann-Cosel, Luisa and Zimmermann, Beate and Hall, Jefferson S. and van Breugel, Michiel and Elsenbeer, Helmut},
  title     = {Soil carbon dynamics under young tropical secondary forests on former pastures-A case study from Panama},
  series = {Forest ecology and management},
  volume    = {261},
  journal   = {Forest ecology and management},
  number    = {10},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0378-1127},
  doi       = {10.1016/j.foreco.2010.07.023},
  pages     = {1625 -- 1633},
  year      = {2011},
  abstract  = {Secondary forests are gaining increased importance in tropical landscapes and have recently been reported to act as potential belowground carbon sinks. While economic interest in the management of secondary forests to mitigate carbon emissions is rising, the dynamics of soil carbon stocks under these ecosystems remain poorly understood. Recent studies report conflicting results concerning soil carbon trends as well as multiple confounding factors (e.g. soil type, topography and land-use history) affecting these trends. In this study, organic carbon stocks were measured in the mineral soil up to 20 cm depth of at 24 active pastures, 5-8-year-old, and 12-15-year-old secondary forest sites on former pastures. Additionally, we estimated carbon stocks under a 100-year-old secondary forest and compared them to those of nearby mature forests. Abiotic conditions in the study area were homogenous, enabling us to isolate the effect of land-use change on soil organic carbon stocks. Contrary to our expectations, soil carbon stocks in the top 10 cm did not change with young secondary forest development. Pasture soils stored 24.8 +/- 2.9 Mg ha(-1) carbon (mean +/- standard error) in the top 10 cm, and no accumulation of soil carbon was apparent during the first 15 years of secondary succession. Soil carbon stocks under 100-year-old secondary forests, averaging 43.0 +/- 7.9 Mg ha(-1) (mean +/- standard error), were clearly higher than those recorded at younger sites and approached levels of soil carbon stocks under mature forests. These data indicate that soil carbon stocks in this region of Panama are not affected by the land-use transition from pasture to young secondary regrowth. However, an increase of soil carbon storage might be possible over a longer period of time. Our results support trends observed in other tropical areas and highlight the importance of environmental conditions such as soil properties rather than land-use transitions on soil carbon dynamics. While our understanding of organic carbon dynamics in tropical soils remains limited, these results underscore the challenges of undertaking short-term reforestation projects with the expectation of increasing soil carbon sequestration.},
  language  = {en}
}
@article{AbdissaHeydenreichMidiwoetal.2014,
  author    = {Abdissa, Negera and Heydenreich, Matthias and Midiwo, Jacob O. and Ndakala, Albert and Majer, Zsuzsanna and Neumann, Beate and Stammler, Hans-Georg and Sewald, Norbert and Yenesew, Abiy},
  title     = {A xanthone and a phenylanthraquinone from the roots of Bulbine frutescens, and the revision of six seco-anthraquinones into xanthones},
  series = {Phytochemistry letters},
  volume    = {9},
  journal   = {Phytochemistry letters},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1874-3900},
  doi       = {10.1016/j.phytol.2014.04.004},
  pages     = {67 -- 73},
  year      = {2014},
  abstract  = {Phytochemical investigation of the dichloromethane/methanol (1:1) extract of the roots of Bulbine frutescens led to the isolation of a new xanthone, 8-hydroxy-6-methylxanthone-1-carboxylic acid (1) and a new phenylanthraquinone, 6',8-O-dimethylknipholone (2) along with six known compounds. The structures were elucidated on the basis of NMR and MS spectral data analyses. The structure of compound 1 was confirmed through X-ray crystallography which was then used as a reference to propose the revision of the structures of six seco-anthraquinones into xanthones. The isolated compounds were evaluated for cytotoxicity against human cervix carcinoma KB-3-1 cells with the phenylanthraquinone knipholone being the most active (IC50 = 0.43 mu M). Two semi-synthetic knipholone derivatives, knipholone Mannich base and knipholone-1,3-oxazine, were prepared and tested for cytotoxic activity; both showed moderate activities (IC50 value of 1.89 and 2.50 mu M, respectively). (C) 2014 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.},
  language  = {en}
}