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Dissertation
Lignocellulosic biorefinery with a thermo-biological pretreatment concept
(2023)
There is great interest, not only in technologically advanced societies, in developing innovative sources of raw materials, especially lignocellulosic biomasses such as cereal straw, which do not interfere with food production. In Germany, 4 – 9 million tons of cereal straw, mainly wheat, are utilized annually, corresponding to an energy potential of 57 – 129 PJ/a. Lignocellulose, found in plant cell walls, consists of hemicellulose, cellulose, and lignin, and it requires complex fractionation to enable its polymers ...
Dissertation
Effects of climate change on fungal community structure and organic matter turnover in soil profiles along elevation gradients in alpine ecosystems
(2019-10)
Although elevation patterns of diversity for plants and animals are well known, understanding of variations in fungal community structure along elevation gradients is limited. Soil fungi play an important role in soil microbial communities, where they improve soil organic matter (SOM) turnover and nutrient circulation. Hence, any change in fungal community structure will have strong effects on soil and ecosystem functioning. The main purpose of this thesis is therefore to investigate how climate induced shifts in ...
Dissertation
Towards crop communities: exploring wheat diversity, wheat-pea species mixtures and farming practice in a food system context
(2022-06)
This thesis combines experimental work on heterogeneous crop populations (HP) and species mixtures (SM) with a social scientific and participatory approach. Chapter 1 introduces crop communities as a concept to integrate multiple approaches to diversify farming systems. HPs provide intraspecific and SM interspecific diversity in crop communities. A key challenge for the genetic improvement of HPs, especially for root traits is to combine effective selection to improve HPs while maintaining intraspecific diversity. ...
Dissertation
Effects of transformation processes in 'jubraka' agroforestry systems of the Nuba Mountains, Sudan, on nutrient fluxes
(2014-03-19)
Intensification processes in homegardens of the Nuba Mountains, Sudan, raise concerns about strongly positive carbon (C) and nutrient balances which are expected to lead to substantial element losses from these agroecosystems, in particular via soil gaseous emissions. Therefore, this thesis aimed at the quantification of C, nitrogen (N), phosphorus (P) and potassium (K) input and output fluxes with a special focus on soil gaseous losses, and the calculation of respective element balances. A further focus in this ...