Refinar búsqueda
Resultados 1-7 de 7
Vertical gradients of ozone and carbon dioxide within a deciduous forest in central Pennsylvania
1996
Skelly, J.M. | Fredericksen, T.S. | Savage, J.E. | Snyder, K.R. (Department of Plant Pathology, Pennsylvania State University, 108 Buckhout Laboratory, University Park, PA 16802 (USA))
Evaluation of ozone injury on foliage of black berry (Prunus serotina) and tall milkweed (Asclepias exaltata) in Great Smoky Mountains National Park
1997
Chappelka, A. | Renfro, J. | Somers, G. | Nash, B. (School of Forestry, Auburn University, Auburn, AL 36849 (USA))
Additive and antagonistic effects of ozone and salinity on the growth, ion contents and gas exchange of five varieties of rice (Oryza sativa L.)
1996
Welfare, K. | Flowers, T.J. | Taylor, G. | Yeo, A.R. (School of Biological Sciences, University of Sussex, Brighton BN1 9QG (United Kingdom))
Allometric relationships between stem volume and the biomass of Norway spruce
1998
Pokorny, R. (Akademie Ved, Brno (Czech Republic). Ustav Ekologie Krajiny)
The objectives of this study were (I) to establish allometric relationships between the stem volume and biomass of the stem, branches, leaves and the leaf area, and crown dimensions of individual trees, (II) to determine the relative aboveground biomass distribution, (III) to determine the vertical gradient of the specific leaf area and (IV) to estimate the aboveground stand biomass and the leaf area. Diameter at 0.3m height above ground and height of each tree were measured as the basic biometrical characteristics. The coefficient of the shape of the trunk was found by Huber's method.
Mostrar más [+] Menos [-]Norway spruce increment as related to the type of branching in the Moravian-Silesian Beskids Mts. [Czech Republic]
1998
Hauck, O. | Palat, M. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic))
Data necessary for the determination of the proportion of various types of branching in stands under study, their variability within a tree, accuracy of classification of the type of branching, damage to particular types of branching due to breakage and initial age for their reliable recognition were obtained according to method from 1,336 trees situated in 11 trial plots in the region of the Beskids. Statistically significant differences were determined in the diameter and height increments for particular types of branching.
Mostrar más [+] Menos [-]Regional pollution potential in the northwestern United States
2003
Ferguson, Sue A. | Rorig, Miriam L.
The potential for air pollution from industrial sources to reach wilderness areas throughout the Northwestern United States is approximated from monthly mean emissions, along with wind speeds and directions. A simple index is derived to estimate downwind concentration. Maps of pollution potential were generated for each pollution component (particulates, sulfur oxides, nitrogen oxides, and ammonia), months representing each season (January, April, July, and October), and each of three vertical levels: surface, 850 mb, and 700 mb. Mixing heights for the last 40 years are used to help determine which trajectory levels best represent each month. Wind frequencies for the same period help show variability and inherent uncertainty in using mean monthly data for pollution-potential estimates.
Mostrar más [+] Menos [-]The effects of ocean acidification and a carbon dioxide capture and storage leak on the early life stages of the marine mussel Perna perna (Linneaus, 1758) and metal bioavailability
2017
Szalaj, D | De Orte, Manoela R | Goulding, T A | Medeiros, I D | DelValls, T Angel | Cesar, A
The study assesses the effects of carbon dioxide capture and storage (CCS) leaks and ocean acidification (OA) on the metal bioavailability and reproduction of the mytilid Perna perna. In laboratory-scale experiments, CCS leakage scenarios (pH 7.0, 6.5, 6.0) and one OA (pH 7.6) scenario were tested using metal-contaminated sediment elutriates and seawater from Santos Bay. The OA treatment did not have an effect on fertilisation, while significant effects were observed in larval-development bioassays where only 16 to 27 % of larva developed normally. In treatments that simulated CO2 leaks, when compared with control, fertilisation success gradually decreased and no larva developed to the D-shaped stage. A fall in pH increased the bioavailability of metals to marine mussels. Larva shell size was significantly affected by both elutriates when compared with seawater; moreover, a significant difference occurred at pH 6.5 between elutriates in the fertilisation bioassay.
Mostrar más [+] Menos [-]