Уточнить поиск
Результаты 1-10 из 11
Linking stress with macroscopic and microscopic leaf response in trees: New diagnostic perspectives
2007
Gunthardt-Goerg, M.S. | Vollenweider, P.
Visible symptoms in tree foliage can be used for stress diagnosis once validated with microscopical analyses. This paper reviews and illustrates macroscopical and microscopical markers of stress with a biotic (bacteria, fungi, insects) or abiotic (frost, drought, mineral deficiency, heavy metal pollution in the soil, acidic deposition and ozone) origin helpful for the validation of symptoms in broadleaved and conifer trees. Differentiation of changes in the leaf or needle physiology, through ageing, senescence, accelerated cell senescence, programmed cell death and oxidative stress, provides additional clues raising diagnosis efficiency, especially in combination with information about the target of the stress agent at the tree, leaf/needle, tissue, cell and ultrastructural level. Given the increasing stress in a changing environment, this review discusses how integrated diagnostic approaches lead to better causal analysis to be applied for specific monitoring of stress factors affecting forest ecosystems. Macroscopic leaf symptoms and their microscopic analysis as stress bioindications.
Показать больше [+] Меньше [-]Seasonal variability and mitigation options for N2O emissions from differently managed grasslands
1998
Kammann, C. | Grunhage, L. | Muller, C. | Jacobi, S. | Jager, H.J. (Institute for Plant Ecology, University of Giessen, Heinrich-Buff-Ring 38, D-35392 Giessen, Germany)
Field application of acid mist to a single clone of Sitka spruce: effects on foliar nutrition and frost hardiness
1997
Sheppard, L.J. | Crossley, A. | Harvey, F.J. | Wilson, D. | Cape, J.N. (Institute of Terrestrial Ecology, Bush Estate, Penicuik, Midlothian, EH26 0QB (United Kingdom))
Effects of acid mist on mature grafts of Sitka spruce. Part I. Frost hardiness and foliar nutrient concentrations
1994
Sheppard, L.J. | Leith, I.D. | Cape, J.N. (Institute of Terrestrial Ecology, Bush Estate, Penicuik EH26 OQB, Midlothian (United Kingdom))
Accelerated dehardening in bilberry (Vaccinium myrtillus L.) induced by a small elevation in air temperature
1997
Taulavuori, K. | Laine, K. | Taulavuori, E. | Pakonen, T. | Saari, E. (Department of Biology, Botany, PO Box 333, University of Oulu, FIN-90571 Oulu (Finland))
Open-top chamber and field exposure of Sitka spruce to simulated acid mist: a comparison of results
1997
Sheppard, L.J. | Leith, I.D. | Morris, E. | Cape, J.N. | Roberts, D. (Institute of Terrestrial Ecology, Bush Estate, Penicuik, Midlothian, EH26 0QB (United Kingdom))
Influence of soil substrate and ozone plus acid mist on the frost resistance of young Norway spruce
1990
Senser, M. (Botanisches Institut der Universitat, 8000 Munich 19 (Germany))
Methane oxidation in a landfill biowindow under wide seasonally fluctuating climatic conditions
2022
Berenjkar, Parvin | Sparling, Richard | Lozecznik, Stan | Yuan, Qiuyan
In the current study, a pilot biowindow was constructed in a closed cell of a Canadian Landfill, undergoing high seasonal fluctuations in the temperature from −30 in winter to 35 in summer. The biowindow was filled with biosolids compost amended with yard waste and leaf compost with the ratio of 4:1 as the substrate layer. Two years of monitoring of methane (CH₄) oxidation in the biowindow led to remarkable expected observations including a thick, solid winter frost cover affecting gas exchange in winter and temperatures above 45 ℃ in the biowindow in late summer. A high influx compared to the reported values was observed into the biowindow with an average value of 1137 g.m⁻².d⁻¹, consisting of 64% of CH₄ and 36% of carbon dioxide (CO₂) in the landfill gas. The variations in the temperature and moisture content (MC) of the compost layer in addition to the influx fluctuations affected CH₄ oxidation efficiency; however, a high average CH₄ oxidation rate of 237 g.m⁻².d⁻¹ was obtained, with CH₄ being mostly oxidized at top layers. The laboratory batch experiments verified that thermophilic methane-oxidizing bacteria (MOB) were active throughout the study period and oxidized CH₄ with a higher rate than mesophilic MOB. The methanotrophic potential of the compost mixture showed an average value of 282 µmol.g⁻¹.d⁻¹ in the entire period of the study which is in the range of the highest reported maximum CH₄ oxidation rates. The adopted compost mixture was suitable for CH₄ oxidation if the MC was above 30%. The significance of MC variations on CH₄ oxidation rate depended on the temperature range within the biowindow. At temperatures below 2 ℃, between 29 and 31℃, and above 45 ℃, MC was not a controlling factor for mesophilic CH₄ oxidation.
Показать больше [+] Меньше [-]Nutrients and structural dynamics of conifer needles in South Sweden 1985-1987
1989
Nihlgaard, B. (Lund University (Sweden). Dep. of Plant Ecology)
Impacts of different freeze-thaw treatments on the adsorption and desorption behaviors of Cd in black soil
2020
Wang, Quanying | Sun, Jingyue | Yu, Hongwen
Seasonal freeze-thaw cycle (FTC) is one of the key processes that affect heavy metal behaviors in soil. However, previous studies are mainly focused on extreme FTC treatments which may exaggerate the real FTC effects in the field. This study aimed to compare the effects of different FTC conditions on the adsorption and desorption behaviors of Cd in the surface black soil. Different minimum freezing temperatures (− 2, − 5, and − 15 °C), FTC rates (1 and 20 °C h⁻¹), freezing lengths (2 and 24 h), and FTC frequencies (1, 3, and 9) were investigated. The thawing temperature was set at 5 °C. The amplitude for the FTC rate, length, and frequency experiments ranged from 5 to − 2 °C. Our results indicated that the adsorption amounts of Cd presented an order of − 2 °C > − 15 °C > − 5 °C and 24 h > 2 h for different FTC amplitude- and freezing length-treated soils, and the adsorption amounts decreased with increasing FTC rate and frequency. Soil maximum adsorption amount of Cd increased with the increases of FTC frequency, freezing length, and FTC rate, while it decreased with the decreases of freezing temperature. Soil Cd desorption ratio decreased with the increases of FTC frequency, freezing length, and TFC rate, and it increased with the increasing freezing temperature. Our results suggested that FTC conditions can significantly influence the adsorption and desorption behaviors of heavy metal in soil.
Показать больше [+] Меньше [-]