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The growth of Calamagrostis villosa at different localities in the Moravian-Silesian Beskids Mts. [Czech Republic]
1998
Holub, P. (Akademie Ved, Brno (Czech Republic). Ustav Ekologie Krajiny) | Pande, K.
Biometrical relationships of volume increment to crown defoliation and other variables of spruce stands in the Oravska Polhora research site [Slovak Republic]
1998
Smelko, S. (Technicka Univ., Zvolen (Slovak Republic). Lesnicka Fakulta)
This contribution deals with the relationship evaluated on the basis of 32 permanent monitoring plots. Tree volume increment as a total "brutto" and also as a pure "netto" change for 1 ha is defined. The first one includes also the influence of felling, mortality and increment ingrowth, second one includes only changes due to the growth process. Relationship of increment to stand variables is investigated bz stepwise regression. A more higher correlation to defoliation was found, less high to age, site index and altitude.
Afficher plus [+] Moins [-]Determination of rainfall-runoff flood hydrograph for small mountainous watersheds
1998
Byczkowski, A | Ignar, S. (Warsaw Agricultural Univ., Warszawa (Poland)) | Chlebek, A. | Jarabac, M.
The subject of the present study is application of the Wackermann conceptual rainfall-runoff model for rainfall flood hydrograph evaluation of small mountainous watersheds. A quasi-physical system concept for transformation of hydrological variables are used in this model. Effective rainfall was determined with the use of Soil Conservation Service method according to analysis of total rainfall and direct flow volumes. The Rosenbrock optimization method was adopted for determinig of model parameters using rainfall and runoff data recorded on the Mala Raztoka mountainous creek in the Moravian Beskid Range.
Afficher plus [+] Moins [-]Natural regeneration of beech under ecologically difficult conditions
1998
Penaz, J. | Martinek, J. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic). Fakulta Lesnicka a Drevarska)
In the region of Knehyne-Velka Stolova in the Moravian-Silesian Beskids, where there are ecologically difficult conditions for functioning forest ecosystems, possibilities were studied for the naturat regeneration of beech. The study of problems was particularly related to generative propagation, however, cases of vegetative propagation were also found. Potential possibilities of regeneration are related to the seed year 1995. Rooting ability of layered branches or lying beech trees wes studied. Analysis is given of a rooting beech branch.
Afficher plus [+] Moins [-]Causes and consequences of mangrove deforestation in the Volta Estuary, Ghana: some recommendations for ecosystem rehabilitation.
1998
Rubin, J. A | Gordon, C. | Amatekpor, J. K.
The damming of the Volta River has resulted in reduced flooding and an increase in mangrove cutting, accompanied by the virtual collapse of agriculture and fishing in the estuary. Another ecological consequence of the reduced level of flooding has been reduced dispersal of seedlings of the principal mangrove, Rhizophora racemosa. Therefore, after cutting of this species, recolonization is either by conspecifics growing at very high densities or by one of a number of weed species, particularly Typha domingensis, Acrostichum aureum, Paspalum vaginatum, Cyperus articulatus, Sesuvium portulacastrum and Philoxerus vermicularis. Environmental data collected in the vicinity of the mangroves and each of the weed species have enabled suggestions to be made as to whether R. racemosa or Avicennia africana would be the more suitable mangrove to replant. Recommendations have also been made to introduce the palm Nypa fruticans to the area, together with the development of nature-based tourism, both of which would provide alternative means of income generation, thereby reducing the need to cut remaining mangroves.
Afficher plus [+] Moins [-]Drinking water supply and agricultural pollution
1998
Schrama, Geerten J. I.
Water pollution risks of methyl tertiary butyl ether (MTBE)
1998
Toxicity, uptake and metabolism of 4-n-nonylphenol in root cultures and intact plants under septic and aseptic conditions Texte intégral
1998
Bokern, Maria | Raid, Petra | Harms, Hans
PLATIN (Plant-Atmosphere Interaction) II: co-occurence of high ambient ozone concentrations and factors limiting plant absorbed dose Texte intégral
1998
Grünhage, Ludger | Jäger, Hans-Jürgen | Haenel, Hans-Dieter | Hanewald, Klaus | Krupa, Sagar V.
Response of a grassland ecosystem to air pollutants : 6. The chemical climate: concentrations and potential flux densities of relevant criteria pollutants Texte intégral
1998
Grünhage, Ludger | Dämmgen, Ulrich | Haenel, Hans-Dieter | Jäger, Hans-Jürgen