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Sonja Wipf - One of the best experts on this subject based on the ideXlab platform.

  • snow cover freeze thaw and the retention of nutrients in an oceanic Mountain Ecosystem
    Ecosphere, 2015
    Co-Authors: Sonja Wipf, Martin Sommerkorn, Marc Stutter, E Jasper R Wubs
    Abstract:

    As the climate warms, winters with less snow and therefore more soil freeze-thaw cycles are likely to become more frequent in oceanic Mountain areas. It is a concern that this might impair the soil's ability to store carbon and nutrients, and lead to increased leaching losses of dissolved C and nutrients and subsequent changes in nutrient cycling and Ecosystem productivity. Through a combination of laboratory and field experiments, we studied short-term effects of changing winter conditions on carbon and nutrient leaching from two plant-soil systems with contrasting snow conditions (shallow/intermittent vs. deep/persistent snow). In the laboratory we exposed cores (soil and vegetation) from sites with either intermittent or persistent winter snow cover to five different freeze-thaw scenarios of realistic frequency and duration. Additionally, we set up a transplant experiment at our field site by reciprocally transplanting soil-plant monoliths between sites with intermittent and persistent snow. Together, the field and laboratory experiments aimed to assess how carbon and nutrient leaching was affected by both historical snow conditions and short-term (through freeze-thaw scenarios and transplantation) changes in snow cover and thermal conditions. Both a greater number of freeze-thaw cycles and longer duration of sub-zero temperatures increased carbon and nutrient leaching from incubated soil cores. Cores from sites with persistent snow generally had lower nutrient losses under control conditions, but greater losses following induced freeze-thaw cycles than cores from intermittent snow sites. The character of the leached dissolved organic carbon (DOC) suggested fresh organic material, such as live plant roots or microbes, as the source of carbon and nutrients. Nutrient losses from the plant-soil systems in the field were greater at sites with persistent winter snow due to greater volumes of percolating water in spring. This suggests that increasingly severe and frequent soil freeze-thaw events in oceanic Mountain Ecosystems can enhance the mobilization of C, N and P in labile forms but, in the absence of water fluxes, these nutrients would remain available for in-situ cycling. Thus, under future warmer winter conditions, increased carbon and nutrient losses from oceanic Mountain Ecosystems could occur if winters with little snow coincide with wet spring conditions.

  • Snow cover, freeze‐thaw, and the retention of nutrients in an oceanic Mountain Ecosystem
    Ecosphere, 2015
    Co-Authors: Sonja Wipf, Martin Sommerkorn, Marc Stutter, E Jasper R Wubs
    Abstract:

    As the climate warms, winters with less snow and therefore more soil freeze-thaw cycles are likely to become more frequent in oceanic Mountain areas. It is a concern that this might impair the soil's ability to store carbon and nutrients, and lead to increased leaching losses of dissolved C and nutrients and subsequent changes in nutrient cycling and Ecosystem productivity. Through a combination of laboratory and field experiments, we studied short-term effects of changing winter conditions on carbon and nutrient leaching from two plant-soil systems with contrasting snow conditions (shallow/intermittent vs. deep/persistent snow). In the laboratory we exposed cores (soil and vegetation) from sites with either intermittent or persistent winter snow cover to five different freeze-thaw scenarios of realistic frequency and duration. Additionally, we set up a transplant experiment at our field site by reciprocally transplanting soil-plant monoliths between sites with intermittent and persistent snow. Together, the field and laboratory experiments aimed to assess how carbon and nutrient leaching was affected by both historical snow conditions and short-term (through freeze-thaw scenarios and transplantation) changes in snow cover and thermal conditions. Both a greater number of freeze-thaw cycles and longer duration of sub-zero temperatures increased carbon and nutrient leaching from incubated soil cores. Cores from sites with persistent snow generally had lower nutrient losses under control conditions, but greater losses following induced freeze-thaw cycles than cores from intermittent snow sites. The character of the leached dissolved organic carbon (DOC) suggested fresh organic material, such as live plant roots or microbes, as the source of carbon and nutrients. Nutrient losses from the plant-soil systems in the field were greater at sites with persistent winter snow due to greater volumes of percolating water in spring. This suggests that increasingly severe and frequent soil freeze-thaw events in oceanic Mountain Ecosystems can enhance the mobilization of C, N and P in labile forms but, in the absence of water fluxes, these nutrients would remain available for in-situ cycling. Thus, under future warmer winter conditions, increased carbon and nutrient losses from oceanic Mountain Ecosystems could occur if winters with little snow coincide with wet spring conditions.

E Jasper R Wubs - One of the best experts on this subject based on the ideXlab platform.

  • snow cover freeze thaw and the retention of nutrients in an oceanic Mountain Ecosystem
    Ecosphere, 2015
    Co-Authors: Sonja Wipf, Martin Sommerkorn, Marc Stutter, E Jasper R Wubs
    Abstract:

    As the climate warms, winters with less snow and therefore more soil freeze-thaw cycles are likely to become more frequent in oceanic Mountain areas. It is a concern that this might impair the soil's ability to store carbon and nutrients, and lead to increased leaching losses of dissolved C and nutrients and subsequent changes in nutrient cycling and Ecosystem productivity. Through a combination of laboratory and field experiments, we studied short-term effects of changing winter conditions on carbon and nutrient leaching from two plant-soil systems with contrasting snow conditions (shallow/intermittent vs. deep/persistent snow). In the laboratory we exposed cores (soil and vegetation) from sites with either intermittent or persistent winter snow cover to five different freeze-thaw scenarios of realistic frequency and duration. Additionally, we set up a transplant experiment at our field site by reciprocally transplanting soil-plant monoliths between sites with intermittent and persistent snow. Together, the field and laboratory experiments aimed to assess how carbon and nutrient leaching was affected by both historical snow conditions and short-term (through freeze-thaw scenarios and transplantation) changes in snow cover and thermal conditions. Both a greater number of freeze-thaw cycles and longer duration of sub-zero temperatures increased carbon and nutrient leaching from incubated soil cores. Cores from sites with persistent snow generally had lower nutrient losses under control conditions, but greater losses following induced freeze-thaw cycles than cores from intermittent snow sites. The character of the leached dissolved organic carbon (DOC) suggested fresh organic material, such as live plant roots or microbes, as the source of carbon and nutrients. Nutrient losses from the plant-soil systems in the field were greater at sites with persistent winter snow due to greater volumes of percolating water in spring. This suggests that increasingly severe and frequent soil freeze-thaw events in oceanic Mountain Ecosystems can enhance the mobilization of C, N and P in labile forms but, in the absence of water fluxes, these nutrients would remain available for in-situ cycling. Thus, under future warmer winter conditions, increased carbon and nutrient losses from oceanic Mountain Ecosystems could occur if winters with little snow coincide with wet spring conditions.

  • Snow cover, freeze‐thaw, and the retention of nutrients in an oceanic Mountain Ecosystem
    Ecosphere, 2015
    Co-Authors: Sonja Wipf, Martin Sommerkorn, Marc Stutter, E Jasper R Wubs
    Abstract:

    As the climate warms, winters with less snow and therefore more soil freeze-thaw cycles are likely to become more frequent in oceanic Mountain areas. It is a concern that this might impair the soil's ability to store carbon and nutrients, and lead to increased leaching losses of dissolved C and nutrients and subsequent changes in nutrient cycling and Ecosystem productivity. Through a combination of laboratory and field experiments, we studied short-term effects of changing winter conditions on carbon and nutrient leaching from two plant-soil systems with contrasting snow conditions (shallow/intermittent vs. deep/persistent snow). In the laboratory we exposed cores (soil and vegetation) from sites with either intermittent or persistent winter snow cover to five different freeze-thaw scenarios of realistic frequency and duration. Additionally, we set up a transplant experiment at our field site by reciprocally transplanting soil-plant monoliths between sites with intermittent and persistent snow. Together, the field and laboratory experiments aimed to assess how carbon and nutrient leaching was affected by both historical snow conditions and short-term (through freeze-thaw scenarios and transplantation) changes in snow cover and thermal conditions. Both a greater number of freeze-thaw cycles and longer duration of sub-zero temperatures increased carbon and nutrient leaching from incubated soil cores. Cores from sites with persistent snow generally had lower nutrient losses under control conditions, but greater losses following induced freeze-thaw cycles than cores from intermittent snow sites. The character of the leached dissolved organic carbon (DOC) suggested fresh organic material, such as live plant roots or microbes, as the source of carbon and nutrients. Nutrient losses from the plant-soil systems in the field were greater at sites with persistent winter snow due to greater volumes of percolating water in spring. This suggests that increasingly severe and frequent soil freeze-thaw events in oceanic Mountain Ecosystems can enhance the mobilization of C, N and P in labile forms but, in the absence of water fluxes, these nutrients would remain available for in-situ cycling. Thus, under future warmer winter conditions, increased carbon and nutrient losses from oceanic Mountain Ecosystems could occur if winters with little snow coincide with wet spring conditions.

Davey L Jones - One of the best experts on this subject based on the ideXlab platform.

  • response of soil phosphorus fractions and fluxes to different vegetation restoration types in a subtropical Mountain Ecosystem
    Catena, 2020
    Co-Authors: Denggao Fu, Xiaoni Wu, Changqun Duan, D R Chadwick, Davey L Jones
    Abstract:

    Abstract Soil phosphorus (P) improvement is one of the important aims of vegetation restoration. However, the effects of different vegetation restoration types on soil P cycling and the underlying mechanisms remain unclear. Together with vegetation structure and soil properties, we measured the soil P fractions and P transformation rates to evaluate the characteristics of ecologically relevant soil P fraction distributions and their dynamics for the most common vegetation restoration types in a subtropical Mountain Ecosystem (i.e., PF, Pinus forest; EF, Eucalyptus forest; SL, shrubland; and NSF, natural secondary forest). We found that water-extractable inorganic P (Pi), organic P (Po), and acid phosphatase activity (APA) were significantly higher in NSF than those in the other vegetation types (P

Jorg Bendix - One of the best experts on this subject based on the ideXlab platform.

  • Ecosystem services biodiversity and environmental change in a tropical Mountain Ecosystem of south ecuador
    2013
    Co-Authors: Jorg Bendix, Erwin Beck, F. Makeschin, Reinhard Mosandl, Achim Brauning, Stefan Scheu, Wolfgang Wilcke
    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.

  • near surface air humidity in a megadiverse andean Mountain Ecosystem of southern ecuador and its regionalization
    Agricultural and Forest Meteorology, 2012
    Co-Authors: Andreas Fries, Rutger Rollenbeck, Thomas Naus, Thorsten Peters, Jorg Bendix
    Abstract:

    Abstract The near surface humidity in a megadiverse Mountain Ecosystem in southern Ecuador is examined on the basis of Relative Humidity (RH) measurements inside the natural Mountain forest and at open sites along an altitudinal gradient from 1700 to 3200 m. The main methodological aim of the current study is to generate a humidity regionalization tool to provide spatial datasets on average monthly mean, minimum and maximum RH, Specific Humidity ( q ) and Specific Saturation Deficit ( D S ) by using observation data of RH. The maps based on data of the period 1999–2009 are needed by ecological projects working on various plots where no climate station data are available. The humidity maps are generated by combining a straightforward detrending technique with a Digital Elevation Model and a satellite-based land cover classification which also provides the relative forest cover per pixel. The topical aim of the study is to investigate the humidity distribution and structure of both manifestations of our Ecosystem (pastures and natural vegetation) with special considerations to the Ecosystem regulation service by converting natural forest into pasture. The results reveal a clear differentiation over the year, partly triggered by the change of synoptic weather situation but also by land cover effects. Humidity amplitudes are particularly low during the main rainy season when cloudiness and rainfall are high, but markedly pronounced in the relative dry season when daily irradiance and outgoing nocturnal radiation causes distinct differences between the land cover units. Particularly the upper pasture areas gained by slash and burn of the natural forest exhibit the lowest humidity values while the humidity inside the Mountain forest is significantly higher due to the regulating effects of the dense vegetation. Thus, clearing the forest clearly reduces the regulation function (regulating Ecosystem services) of the Ecosystem which might become problematic for reforestation under future global warming.

  • optical properties of selected plants from a tropical Mountain Ecosystem traits for plant functional types to parametrize a land surface model
    Ecological Modelling, 2011
    Co-Authors: Dietrich Gottlicher, Janina Albert, Thomas Nauss, Jorg Bendix
    Abstract:

    Abstract The optical properties (reflectance and transmittance) of selected leaves from a tropical Mountain rainforest in southern Ecuador are determined to parametrize optical traits of plant functional types (PFT) of a state of the art land model (Community Land Model, CLM). 46 spatially dominating species are selected from 4 different forest types, the subparamo and a succession stage of pasture areas representing ecologically predefined functional types within the study area. Measurements are conducted under a standardized experimental setup with a field spectrometer covering the radiation between 305 and 1305 nm. The results of the optical properties of all species are checked for similarity by cluster analysis and are compared to the composition of species of the predefined PFTs. Furthermore the results are compared to other studies, the default values for the globally defined PFT of tropical evergreen trees in the CLM and another forest growth model operated in the same study area. The results show that the clusters aggregated by the reflectance, transmittance or combined properties do not represent the predefined PFTs. The values of the other studies suggest a reassessment of the experimental setup for the transmittance measurements. Nevertheless, new reflectance values for the regionalized PFTs can be determined. The optical values differ from the CLM-PFT of tropical evergreen trees, and new values for the reflectance are recommended.

  • gradients in a tropical Mountain Ecosystem of ecuador
    2008
    Co-Authors: Erwin Beck, Ingrid Kottke, F. Makeschin, Jorg Bendix, Reinhard Mosandl
    Abstract:

    Part I Introduction 1 The Ecosystem (Reserva Biologica San Francisco) E. Beck, F. Makeschin, F. Haubrich, M. Richter, J. Bendix, C. Valerezo 2 Mountain rain forests in southern Ecuador as a hotspot of biodiversity - Limited knowledge and diverging patterns G. Brehm, J. Homeier, K. Fiedler, I. Kottke, J. Illig, N.M. Noske, F. Werner, S-W. Breckle 3 The people settled around Podocarpus National Park P. Pohle 4 Ecuador suffers the highest deforestation rate in South America R. Mosandl, S. Gunter, B. Stimm, M. Weber 5 Methodological challenges of a megadiverse Ecosystem G. Brehm, K. Fiedler, Ch. Hauser, H. Dalitz Part II Gradients in Ecosystem analysis 6 Why investigating gradients in Ecosystem analysis K. Fiedler, E. Beck 7 The investigated gradients E. Beck, R. Mosandl, M. Richter, I. Kottke Part III The altitudinal gradient Part III.1 Gradual changes along the altitudinal gradient 8 Climate J. Bendix, R. Rollenbeck, M. Richter, P. Fabian, P. Emck 9 Soils along the altitudinal transect and in catchments W. Wilcke, S. Yasin, A Schmitt, C. Valarezo, W. Zech 10 Flora: Composition and function 10.1 Potential vegetation and floristic composition of Andean forests in South Ecuador, with a focus on the RBSF J. Homeier, F. A. Werner, S. R. Gradstein, S -W. Breckle, M. Richter 10.2 Past vegetation and fire dynamics H. Niemann & H. Behling 10.3 Forest structure along an altitudinal gradient in southern Ecuador A. Paulsch, D. Piechowski, K. Muller-Hohenstein 10.4 Vegetation structures and ecological features of the upper timberline ecotone M. Richter, K.-H. Diertl, Th. Peters, R. W. Bussman 10.5 Mycorrhizal state and new and special features of mycorrhizae of trees, ericads, orchids, ferns andliverworts I. Kottke, A. Beck, I. Haug, S. Setaro, V. Jeske, J.P. Suarez, L. Paxmino, M. Preussing, M, Nebel, F. Oberwinkler 11 Fauna: Composition and function 11.1 Bird species distribution along an altitudinal gradient in southern Ecuador and its functional relationships with vegetation structure D. Paulsch and K. Muller-Hohenstein 11.2 Seed dispersal by birds, bats and wind F. Matt, K. Almeida, A. Arguero, C. Reudenbach 11.3 Variation of diversity patterns across moth families along a tropical elevational gradient K. Fiedler, G. Brehm, N. Hilt, D. Sussenbach, and C.L. Hauser 11.4 Soil fauna M. Maraun, J. Illig , D. Sandman,V. Krashevskaya, R.A. Norton, S. Scheu Part III.2 Processes along and within the gradient 12 Water relations W. Wilcke, S. Yasin, K. Fleischbein, R. Goller, J. Boy, J. Knuth, C. Valarezo, W. Zech 13 Nutrient status and fluxes at the field and catchment scale W. Wilcke, S.Yasin, K. Fleischbein, R. Goller, J. Boy, J. Knuth, C. Valarezo, W. Zech 14 Biotic soil activities S. Iost, F. Makeschin, M. Abiy, F. Haubrich 15 Elevational changes in stand structure and biomass allocation of tropical Mountain forests in relation to microclimate and soil chemistry G. Moser, M. Roderstein, N. Soethe, D. Hertel, C. Leuschner 16 Stand structure, transpiration responses in trees and vines and stand transpiration of different forest types within the Mountain rainforest M. Kuppers, T. Motzer,D. Schmitt., C. Ohlemacher, R. Zimmermann, V. Horna, B.I.L. Kuppers, T. Mette 17 Plant growth along the altitudinal gradient-role of plant nutritional status, fine root activity, and soil properties N. Soethe, W. Wilcke, J. Homeier, J. Lehmann, C. Engels Part III.3 Gradient heterogeneities Part III.3.A Spatial heterogeneities 18 Spatial

Mingjiang Zhang - One of the best experts on this subject based on the ideXlab platform.

  • dynamics of soil microbial communities following vegetation succession in a karst Mountain Ecosystem southwest china
    Scientific Reports, 2019
    Co-Authors: Chang Zhao, Jian Long, Hongkai Liao, Chunli Zheng, Juan Li, Mingjiang Zhang
    Abstract:

    The interaction between soil property and soil microbial community in karst area still remains an open question. The characteristics of soil physicochemical properties and microbial community structure and their relationship under five vegetation succession stages (grassland, shrub land, secondary forest, plantation forest, and natural forest) at two soil depths (0–10 cm and 10–20 cm) were explored in a karst Mountain Ecosystem. We found that soil moisture content (SMC) and pH increased with soil depth across vegetation succession. The highest content of soil nutrients was found in the natural forest stage at both soil depths. The total PLFAs, the abundance of Gram-positive (GP) bacteria, actinomycetes (ACT), fungi, and arbuscular mycorrhizal fungi (AMF) were significantly (P < 0.05) related to variations with soil total carbon (TC) and total nitrogen (TN). Furthermore, the distribution of soil microbial community distinctly differed in vegetation succession both at two soil layers which was demonstrated by Principal-coordinates analysis. Redundancy analyses patterns indicated that soil TC and TN were positively related to cy19:0 and 10Me 16:0, but an opposite relationship with a15:0. Changes of soil microbial communities were significantly determined by vegetation succession, and soil microbial community structure can be a sensitive indicator to reflect the stabilization of karst Mountain Ecosystem, southwest of China.

  • Dynamics of soil microbial communities following vegetation succession in a karst Mountain Ecosystem, Southwest China.
    Scientific Reports, 2019
    Co-Authors: Chang Zhao, Jian Long, Hongkai Liao, Chunli Zheng, Juan Li, Mingjiang Zhang
    Abstract:

    The interaction between soil property and soil microbial community in karst area still remains an open question. The characteristics of soil physicochemical properties and microbial community structure and their relationship under five vegetation succession stages (grassland, shrub land, secondary forest, plantation forest, and natural forest) at two soil depths (0–10 cm and 10–20 cm) were explored in a karst Mountain Ecosystem. We found that soil moisture content (SMC) and pH increased with soil depth across vegetation succession. The highest content of soil nutrients was found in the natural forest stage at both soil depths. The total PLFAs, the abundance of Gram-positive (GP) bacteria, actinomycetes (ACT), fungi, and arbuscular mycorrhizal fungi (AMF) were significantly (P