@article{SchulzVoigtBeuschetal.2016,
  author    = {Schulz, Katharina and Voigt, Karsten and Beusch, Christine and Almeida-Cortez, Jarcilene S. and Kowarik, Ingo and Walz, Ariane and Cierjacks, Arne},
  title     = {Grazing deteriorates the soil carbon stocks of Caatinga forest ecosystems in Brazil},
  series = {Forest ecology and management},
  volume    = {367},
  journal   = {Forest ecology and management},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0378-1127},
  doi       = {10.1016/j.foreco.2016.02.011},
  pages     = {62 -- 70},
  year      = {2016},
  abstract  = {Grazing by domestic ungulates can have substantial impacts on forests in arid and semi-arid regions, possibly including severe loss of carbon from the soil. Predicting net livestock impacts on soil organic carbon stocks remains challenging, however, due to the dependence on animal loads and on soil and environmental parameters. The objective of this study was to better understand grazing effects on soil organic carbon in seasonal tropical dry forests of north-eastern Brazil (Caatinga) by quantifying carbon stocks of the upper soil profile (0-5 cm depth) and greater soil depths (>5 cm depth down to bedrock) along a gradient of grazing intensity while accounting for other influencing factors such as soil texture, vegetation, landscape topography, and water availability. We analysed soil organic carbon, soil clay content, altitude above sea level, soil depth to bedrock, distance to the nearest permanent water body, species diversity of perennial plants and aboveground biomass on 45 study plots located in the vicinity of the Itaparica Reservoir, Pernambuco, Brazil. Livestock (mainly goats and cattle) are unevenly distributed in the studied ecosystem, thus grazing intensity was accounted for based on the weight of livestock droppings per square metre and classified as no or light, intermediate, or heavy grazing. The mean soil organic carbon in the area was 16.86 ± 1.28 Mg ha\&\#8722;1 C with approximately one-quarter found in the upper 5 cm of the soil profile (4.14 ± 0.43 Mg ha\&\#8722;1 C) and the remainder (12.57 ± 0.97 Mg ha\&\#8722;1 C) in greater soil depths (>5 cm). Heavy grazing led to significantly lower soil organic carbon stocks in the upper 5 cm, whereas no effect on soil organic carbon of the soil overall or in greater soil depths was detectable. The soil's clay content and the altitude proved to be the most relevant factors influencing overall soil organic carbon stocks and those in greater soil depths (>5 cm). Our findings suggest that grazing causes substantial release of carbon from Brazilian dry forest soils, which should be addressed through improved grazing management via a legally compulsory rotation system. This would ultimately contribute to the conservation of a unique forest system and associated ecosystem services.},
  language  = {en}
}
@article{GuoLohmannRatzmannetal.2016,
  author    = {Guo, Tong and Lohmann, Dirk and Ratzmann, Gregor and Tietjen, Britta},
  title     = {Response of semi-arid savanna vegetation composition towards grazing along a precipitation gradient-The effect of including plant heterogeneity into an ecohydrological savanna model},
  series = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog},
  volume    = {325},
  journal   = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0304-3800},
  doi       = {10.1016/j.ecolmodel.2016.01.004},
  pages     = {47 -- 56},
  year      = {2016},
  abstract  = {Ecohydrological models of savanna rangeland systems typically aggregate plant species to very broad plant functional types (PFTs), which are characterized by their trait combinations. However, neglecting trait variability within modelled PFTs may hamper our ability to understand the effects of climate or land use change on vegetation composition and thus on ecosystem processes. In this study we extended and parameterized the ecohydrological savanna model EcoHyD, which originally considered only three broad PFTs (perennial grasses, annuals and shrubs). We defined several sub-types of perennial grasses (sub-PFTs) to assess the effect of environmental conditions on vegetation composition and ecosystem functioning. These perennial sub-PFTs are defined by altering distinct trait values based on a trade-off approach for (i) the longevity of plants and (ii) grazing-resistance. We find that increasing grazing intensity leads to a dominance of the fast-growing and short-lived perennial grass type as well as a dominance of the poorly palatable grass type. Increasing precipitation dampens the magnitude of grazing-induced shifts between perennial grass types. The diversification of perennial grass PFTs generally increases the total perennial grass cover and ecosystem water use efficiency, but does not protect the community from shrub encroachment. We thus demonstrate that including trait heterogeneity into ecosystem models will allow for an improved representation of ecosystem responses to environmental change in savannas. This will help to better assess how ecosystem functions might be impacted under future conditions. (C) 2016 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{GurkeVidalGorosquietaPajimansetal.2021,
  author    = {Gurke, Marie and Vidal-Gorosquieta, Amalia and Pajimans, Johanna L. A. and Wȩcek, Karolina and Barlow, Axel and Gonz{\´a}lez-Fortes, Gloria M. and Hartmann, Stefanie and Grandal-d'Anglade, Aurora and Hofreiter, Michael},
  title     = {Insight into the introduction of domestic cattle and the process of Neolithization to the Spanish region Galicia by genetic evidence},
  series = {PLoS ONE},
  volume    = {16},
  journal   = {PLoS ONE},
  number    = {4},
  publisher = {Public Library of Science},
  address   = {San Francisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0249537},
  pages     = {15},
  year      = {2021},
  abstract  = {Domestic cattle were brought to Spain by early settlers and agricultural societies. Due to missing Neolithic sites in the Spanish region of Galicia, very little is known about this process in this region. We sampled 18 cattle subfossils from different ages and different mountain caves in Galicia, of which 11 were subject to sequencing of the mitochondrial genome and phylogenetic analysis, to provide insight into the introduction of cattle to this region. We detected high similarity between samples from different time periods and were able to compare the time frame of the first domesticated cattle in Galicia to data from the connecting region of Cantabria to show a plausible connection between the Neolithization of these two regions. Our data shows a close relationship of the early domesticated cattle of Galicia and modern cow breeds and gives a general insight into cattle phylogeny. We conclude that settlers migrated to this region of Spain from Europe and introduced common European breeds to Galicia.},
  language  = {en}
}