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Wahren A.,Institute of Soil Science and Site Ecology | Wahren A.,Dr. Dittrich and Partner Hydro Consult GmbH | Berkhoff K.,Leibniz University of Hanover | Herrmann S.,Leibniz University of Hanover | Feger K.-H.,Institute of Soil Science and Site Ecology
Advances in Geosciences | Year: 2010

The opening up of China's industry towards market orientation has a distinct impact on natural resources as well as on social structures. The example of rubber introduction in Yunnan province (SW China) shows the mutual interdependencies between economy, natural resources, and social structures. We assess the impacts of rubber introduction and possible development paths in the study area. An integrated modeling framework (NabanFrame) is developed for the catchment of the Naban River (size 270 km2), a tributary to the Mekong River. NabanFrame comprises an agro-economic, ecological, and social model. Altogether they interact with a land-use change model via defined interfaces. Effects on the water cycle are considered by additionally integrating the spatially distributed rainfall-runoff and water balance model AKWA-M® in the model framework. Therefore, a reasonable parameterization is needed to assess the land-use changes on areal water fluxes. The authors conclude that the chosen hydrological model is able to assess the impacts of land conversion (from forest to rubber plantations) on catchment hydrology and address further adaptations to be implemented in the hydrological model. © 2010 Author(s).

Hagemann U.,Institute of Soil Science and Site Ecology | Moroni M.T.,Natural Resources Canada | Shaw C.H.,Natural Resources Canada | Kurz W.A.,Natural Resources Canada | Makeschin F.,Institute of Soil Science and Site Ecology
Ecological Modelling | Year: 2010

Understanding the effects of disturbance regimes on carbon (C) stocks and stock changes is a prerequisite to estimating forest C stocks and fluxes. Live-tree, dead-tree, woody debris (WD), stump, buried wood, organic layer, and mineral soil C stock data were collected from high-boreal black spruce (Picea mariana (Mill.) B.S.P.) stands of harvest and fire origin and compared to values predicted by the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3); the core model of Canada's National Forest Carbon Monitoring, Accounting and Reporting System. Data comparing the effect of natural and anthropogenic disturbance history on forest C stocks are limited, but needed to evaluate models such as the CBM-CFS3. Results showed that adjustments to the CBM-CFS3 volume-to-biomass conversion and partitioning parameters were required for the non-merchantable and branch C pools to accurately capture live-tree C stocks in the studied black spruce ecosystems. Accuracy of the CBM-CFS3 modelled estimates of dead organic matter and soil C pools was improved relative to regional default parameters by increased snag fall and >10 cm WD base decay rates. The model evaluation process also highlighted the importance of developing a bryophyte module to account for bryophyte C dynamics and the physical burial of woody debris by bryophytes. Modelled mineral soil C estimates were improved by applying a preliminary belowground slow C pool base decay rate optimized for the soil type of the studied sites, Humo-Ferric Podzols. Crown Copyright © 2009.

Zhang K.,TU Dresden | Peschel D.,Martin Luther University of Halle Wittenberg | Klinger T.,Institute of Soil Science and Site Ecology | Gebauer K.,TU Dresden | And 2 more authors.
Carbohydrate Polymers | Year: 2010

Both sulfate and carboxyl groups are found in many glycosaminoglycans exhibiting diverse biological activities, such as heparin. Present study reports on the preparation of cellulose derivatives containing both sulfate and carboxyl groups that were regioselectively introduced into anhydroglucose units (AGU) of cellulose. The products - carboxyl cellulose sulfates (COCS) - with various contents of both functional groups were obtained by two synthesis routes. One way started with sulfation of cellulose yielding cellulose sulfate (CS) and was followed by TEMPO-mediated oxidation of CS. In another way, cellulose at first underwent TEMPO-mediated oxidation yielding carboxyl cellulose (COC). Subsequently, acetosulfation of the COC was carried out. The products were characterized by diverse analysis methods, and the amounts of both functional groups in CS, COC and COCS were determined. Finally, the biological activity of COCS was examined. © 2010.

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