خيارات البحث
النتائج 1 - 10 من 38
The Sikfokut forest dirt study: early results from a successful LTER/ILTER cross-site collaboration
2002
Vanderbilt, K. (University of New Mexico, Albuquerque (USA). Department of Biology) | Toth, J. A. | Caldwell, B. | Bowden, R. | Lajtha, K.
A DIRT (Detritus Input and Removal Treatments) experiment was initiated at the Sikfokut Forest LTER site in Hungary in November 2000. This study was designed to evaluate how sources and quantities of litter inputs control nutrient cycling and carbon storage in forest soils across sites with different climate, C and N status. Sikfokut Forest was selected for its high N deposition rate compared the Harvard Forest LTER, Bousson Forest and Andrews Forest LTER DIRT experiment sites in the United States. Trends in soil enzyme phosphatase and beta-glucosidase activity at Sikfokut indicate that the microbial community there is already clearly responding to reduced litter availability after only two years of treatment
اظهر المزيد [+] اقل [-]Implementation of remediation measures in forests with the emphasis on the forests in Spis region
2002
Vosko, M. (Forest Research Institute, Zvolen (Slovak Republic))
Major part of implemented measures was aimed at early artificial forest regeneration and securing plantations, or protection of young forest stands against damage by bark beetles. Only exceptionally there were proposed measures with the aim to increase vitality, stability and improvement of the structure of forest stands by their tending. It was worked out a draft of procedures for forest managers to help them in deciding at which stocking it is necessary to reforest reduced or actual clearings, whether to fell down open stands or to leave them regarding their age, state and expected further development
اظهر المزيد [+] اقل [-]The progress and perspectives of ILTER research in Poland
2002
Zalewski, M. (Polish Academy of Sciences, Warsaw (Poland). International Centre for Ecology)
The general conclusions of Warsaw ILTER meeting was that following ILTER philosophy, ecological processes integrity can be maintained on the basis of profound knowledge on the rate of changes, hierarchy of driving forces and resistance and resilience of ecosystems. To achieve such complex understanding of these processes there is a need , first to collect and analyze broad spectrum of data possibly standardized by methodology and next permanently exchange information with coordinators from other countries and regions. As a consequence the participants suggested to extend the initial number of 6 sites situated mostly at National Parks and MAB Biosphere Reserve by the new sites representing broader scope of ecosystems and wider range of its anthropogenic modifications. This should allow to define the regional hierarchy of factors deteriorating the ecological systems and create better scope for comparative studies for global environment
اظهر المزيد [+] اقل [-]The Hungarian ILTER sites and their activities in 2002
2002
Kovacs-Lang, E. | Kertesz, M. | Toth, J. A.
The Hungarian ILTER Network consists of three sites representing the characteristic biomes in the country: lake Balaton ILTER site, Sikofut oak forest ILTER site, and the Kiskun sand forest-steppe ILTER site. Hungarian ecologists have developed broad multidisciplinary research projects, which can meet both the requirements of international research standards and the domestic needs of nature conservation and environment protection. Hungarian policy and decision makers have also recognised the importance of long-term ecological research. As a consequence different grants such as Hungarian R + D "Szechenyi", EU FWS Projects, OTKA and OTKA-NSF Projects, Joint grant of Ministry of Environment and the Hungarian Academy of Sciences were awarded in the last 2-3 years, what could create the basis of national and international research cooperations of Hungarian ILTER sites
اظهر المزيد [+] اقل [-]Effects of ozone (O3) and ethylenediurea (EDU) on the ecological stoichiometry of a willow grown in a free-air exposure system
2018
Agathokleous, Evgenios | Kitao, Mitsutoshi | Qingnan, Chu | Saitanis, Costas J. | Paoletti, Elena | Manning, William J. | Watanabe, Toshihiro | Koike, Takayoshi
Ground-level ozone (O3) concentrations have been elevating in the last century. While there has been a notable progress in understanding O3 effects on vegetation, O3 effects on ecological stoichiometry remain unclear, especially early in the oxidative stress. Ethyelenediurea (EDU) is a chemical compound widely applied in research projects as protectant of plants against O3 injury, however its mode of action remains unclear. To investigate O3 and EDU effects early in the stress, we sprayed willow (Salix sachalinensis) plants with 0, 200 or 400 mg EDU L−1, and exposed them to either low ambient O3 (AOZ) or elevated O3 (EOZ) levels during the daytime, for about one month, in a free air O3 controlled exposure (FACE); EDU treatment was repeated every nine days. We collected samples for analyses from basal, top, and shed leaves, before leaves develop visible O3 symptoms. We found that O3 altered the ecological stoichiometry, including impacts in nutrient resorption efficiency, early in the stress. The relation between P content and Fe content seemed to have a critical role in maintaining homeostasis in an effort to prevent O3-induced damage. Photosynthetic pigments and P content appeared to play an important role in EDU mode of action. This study provides novel insights on the stress biology which are of ecological and toxicological importance.
اظهر المزيد [+] اقل [-]Concern-driven integrated approaches for the grouping, testing and assessment of nanomaterials
2016
Landsiedel, Robert
NM's potential to induce adverse effects in humans or the environment is being addressed in numerous research projects, and methods and tools for NM hazard identification and risk assessment are advancing. This article describes how integrated approaches for the testing and assessment of NMs can ensure the safety of nanomaterials, while adhering to the 3Rs principle.
اظهر المزيد [+] اقل [-][The pesticide research in the Strategic Environment Framework]
1997
Albrechtsen, H.-J. | Hansen, J.M.
Developing human capital for successful implementation of international marine scientific research projects
2013
Morrison, R.J. | Zhang, J. | Urban, E.R. | Hall, J. | Ittekkot, V. | Avril, B. | Hu, L. | Hong, G.H. | Kidwai, S. | Lange, C.B. | Lobanov, V. | Machiwa, J. | San Diego-McGlone, M.L. | Oguz, T. | Plumley, F.G. | Yeemin, T. | Zhu, W. | Zuo, F.
The oceans play a crucial role in the global environment and the sustainability of human populations, because of their involvement in climate regulation and provision of living and non-living resources to humans. Maintenance of healthy oceans in an era of increasing human pressure requires a high-level understanding of the processes occurring in the marine environment and the impacts of anthropogenic activities. Effective protection and sustainable resource management must be based, in part, on knowledge derived from successful research. Current marine research activities are being limited by a need for high-quality researchers capable of addressing critical issues in broad multidisciplinary research activities. This is particularly true for developing countries which will require the building of capacity for marine scientific research. This paper reviews the current activities aimed at increasing marine research capacity in developing and emerging countries and analyses the challenges faced, including: appropriate alignment of the research goals and societal and policy-relevant needs; training in multidisciplinary research; increasing capacity for overall synthesis of scientific data; building the capacity of technical staff; keeping highly qualified personnel in marine scientific research roles; cross-cultural issues in training; minimising duplication in training activities; improving linkages among human capital, project resources and infrastructure. Potential solutions to these challenges are provided, along with some priorities for action aimed at improving the overall research effort.
اظهر المزيد [+] اقل [-]Nitrogen saturation experiments (NITREX) in coniferous forest ecosystems in Europe: a summary of results
1998
Tietema, A. | Boxman, A.W. | Bredemeier, M. | Emmett, B.A. | Moldan, F. | Gundersen, P. | Schleppi, P. | Wright, R.F. (University of Amsterdam, Netherlands Centre for Geo-Ecological Research, Nieuwe Prinsengracht 130, NL1018 VZ Amsterdam (Netherlands))
Investigating the performance of hydroponic nutrient solutions as potential draw solutions for fertilizer drawn forward osmosis
2022
Bassiouny, Mohamed | Nasr, Peter | Sewilam, Hani
This research project aims at investigating the performance of hydroponic nutrient solutions as draw solutions for desalination using the fertilizer drawn forward osmosis (FDFO) process. Six different lettuce and leafy greens hydroponic nutrient stock solutions were prepared according to the literature and used in this study and tested on a bench-scale forward osmosis unit as draw solutions for the process. The feed solution for the process was deionized water mixed with NaCl in different concentrations, to represent different salinities of brackish groundwater. The draw efficiency of each solution was measured based on water flux, specific reverse solute flux, water recovery, and salt rejection. It was concluded that of the six tested nutrient solutions, the “Resh Florida, California” solution is the recommended solution to be used as draw solution for fertilizer drawn forward osmosis, due to its high performance in terms of water recovery (15.75%), flux (11 L/m²/h), salt rejection (92%), and SRSF (highest recorded SRSF for a specific ion (SO₄²⁻) was 7.3 g/L), as well as its low cost, relative to the other highly performing draw solution “Chekli” ($1.07/L vs. $3.73/L).
اظهر المزيد [+] اقل [-]