@misc{WilckeLeimerPetersetal., author = {Wilcke, Wolfgang and Leimer, Sophia and Peters, Thorsten and Emck, Paul and Rollenbeck, R{\"u}tger and Trachte, Katja and Valarezo, Carlos}, title = {The nitrogen cycle of tropical montane forest in Ecuador turns inorganic under environmental change}, series = {Global Biogeochemical Cycles}, volume = {27}, journal = {Global Biogeochemical Cycles}, number = {4}, doi = {10.1002/2012GB004471}, pages = {1194 -- 1204}, abstract = {[1] Water-bound nitrogen (N) cycling in temperate terrestrial ecosystems of the Northern Hemisphere is today mainly inorganic because of anthropogenic release of reactive N to the environment. In little-industrialized and remote areas, in contrast, a larger part of N cycling occurs as dissolved organic N (DON). In a north Andean tropical montane forest in Ecuador, the N cycle changed markedly during 1998-2010 along with increasing N deposition and reduced soil moisture. The DON concentrations and the fractional contribution of DON to total N significantly decreased in rainfall, throughfall, and soil solutions. This inorganic turn of the N cycle was most pronounced in rainfall and became weaker along the flow path of water through the system until it disappeared in stream water. Decreasing organic contributions to N cycling were caused not only by increasing inorganic N input but also by reduced DON production and/or enhanced DON decomposition. Accelerated DON decomposition might be attributable to less waterlogging and higher nutrient availability. Significantly increasing NO3-N concentrations and NO3-N/NH4-N concentration ratios in throughfall and litter leachate below the thick organic layers indicated increasing nitrification. In mineral soil solutions, in contrast, NH4-N concentrations increased and NO3-N/NH4-N concentration ratios decreased significantly, suggesting increasing net ammonification. Our results demonstrate that the remote tropical montane forests on the rim of the Amazon basin experienced a pronounced change of the N cycle in only one decade. This change likely parallels a similar change which followed industrialization in the temperate zone of the Northern Hemisphere more than a century ago.}, language = {en} } @incollection{BreuerExbrayatPlescaetal., author = {Breuer, Lutz and Exbrayat, Jean-Fran{\c{c}}ois and Plesca, Ina and Buytaert, Wouter and Ehmann, Theresa and Peters, Thorsten and Timbe, Edison and Trachte, Katja and Windhorst, David}, title = {Global Climate Change Impacts on Local Climate and Hydrology}, series = {Ecosystem Services, Biodiversity and Environmental Change in a Tropical Mountain Ecosystem of South Ecuador}, booktitle = {Ecosystem Services, Biodiversity and Environmental Change in a Tropical Mountain Ecosystem of South Ecuador}, edition = {1}, publisher = {Springer-Verlag GmbH}, address = {Berlin [u.a.]}, isbn = {978-3-642-38137-9}, doi = {10.1007/978-3-642-38137-9_19}, pages = {265 -- 274}, abstract = {An interdisciplinary research unit consisting of 30 teams in the natural, economic and social sciences analyzed biodiversity and ecosystem services of a mountain rainforest ecosystem in the hotspot of the tropical Andes, with special reference to past, current and future environmental changes. The group assessed ecosystem services using data from ecological field and scenario-driven model experiments, and with the help of comparative field surveys of the natural forest and its anthropogenic replacement system for agriculture. The book offers insights into the impacts of environmental change on various service categories mentioned in the Millennium Ecosystem Assessment (2005): cultural, regulating, supporting and provisioning ecosystem services. Examples focus on biodiversity of plants and animals including trophic networks, and abiotic/biotic parameters such as soils, regional climate, water, nutrient and sediment cycles. The types of threats considered include land use and climate changes, as well as atmospheric fertilization. In terms of regulating and provisioning services, the emphasis is primarily on water regulation and supply as well as climate regulation and carbon sequestration. With regard to provisioning services, the synthesis of the book provides science-based recommendations for a sustainable land use portfolio including several options such as forestry, pasture management and the practices of indigenous peoples. In closing, the authors show how they integrated the local society by pursuing capacity building in compliance with the CBD-ABS (Convention on Biological Diversity - Access and Benefit Sharing), in the form of education and knowledge transfer for application.}, language = {en} }