Alluvial Meadow Research Articles

Springtime Migration and Growth of Parameletus Chelifer (Ephemeroptera) in a Temporary Stream in Northern Sweden

The upstream migration of the nymphs of the mayfly Parameletus chelifer Bgtss., in a temporary stream, tributary to the river Vindelalven in northern Sweden, was investigated in May 1977. The tributary drains an alluvial meadow which has usually dried out by the middle of July. The upstream movement of nymphs lasted for about nine days, during which period hundreds of thousands of P. chelifer moved from the main river up into the small stream. The nymphs on the alluvial meadow grew significantly faster than did those in the river, probably because of a higher water temperature and a more plentiful supply of food in the temporary stream. Before the stream dried up completely the nymphs had emerged. Newly hatched nymphs were found in the main river in February. Thus, it seems as if P. chelifer has a colonization cycle which includes an upstream movement of nymphs and a subsequent 'downstream' return flight of adults.

Litter production and disappearance in some alluvial meadows (Preliminary results)

Data on standing crop of litter, litter production and disappearance in three alluvial meadow plant communities are presented. The influence of ecological conditions and quality of litter on litter decomposition rate, and the chemical changes of litter during decomposition are described.

Heavy metals in the soils Euro-Arctic territories

The features of metal accumulation by the Arctic soils are analyzed. The data of a comparative analysis content of total and metals mobile forms in natural and anthropogenic soils in the Euro-Arctic region are presented. Such areas studied: Frans Joseph Land, Spitsbergen, Solovetsky, Novaya Zemlya, Kolguev Island, cape Kanin Nos, Varnek, Sosnovets Island. The chemical analysis was carried out with the use of modern instrumental methods and certified methods: by X-ray fluorescence and atomic absorption methods. The degree of soil contamination was assessed by the maximum permissible concentrations exceeding and biogeochemical coefficients. Analysis of the experimental data has shown that metals accumulation by different types of soils is ambiguous: zinc and lead predominate in the arctic and tundra bog soils, manganese and cobalt in the non-gley and gley tundra soils, and cobalt and lead in the podzolic and alluvial meadow soils. Correlation analysis revealed the dependence of the metals accumulation with such physicochemical parameters as the content of physical clay, organic matter and the pH of the soil solution. According to the total pollution index (Zc), calculated related to clark, a dangerous level of contamination have the Arctic soils of Pyramid settlement, tundra non-gley soils of cape Belyy Nose, alluvial meadow acidic soils of Dixon settlement and peat soils of Sosnowiec Island. Tundra gley soils in Cape Kanin Nos have a moderately dangerous level of pollution. At the same time, the soils have an acceptable level of contamination with metals mobile forms. Practically all of the examined elements are represented by non-mobile forms, which are confirmed by the high value of the protective soils coefficients.