Coastal meadow communities ‘Randu meadows’

1996 – up to now.

Viesturs Melecis

Botanical reserve “Randu meadows” is situated on the northern coast of the Riga Gulf (latitude 57°15’N, longitude 24°20’E). The botanical reserve is a part of the North Vidzeme Biosphere Reserve. It represents about 200 ha of unique coastal meadows with high habitat and species diversity. There were recorded 531 plant species, 42 are rare and protected in Latvia, 2 species are on the EU Biotope Directive 92/43/EEC list.

Grassland habitats and wetlands are important nesting place for 18 rare and endagered bird species. There are also 4 protected species of mammals and 3 species of amphibians. Man has participated in the development of these littoral meadows for hundreds of years, by cattle grazing and hay harvesting. Recently, the intensity of grazing and mowing have sharply decreased, and the meadows are gradually overgrowing by reeds and shrubs. Wild cattle herd was introduced in part of the grassland area in order to prevent overgrowth of meadows.

18 permanent sampling plots (26x2m) are arranged on seven systematically selected transects. Position of each plot on the transect line was selected randomly within the main territorial compartmens (sea coast, middle part, forest edge) and represent different meadow habitats from xeric, mesic and hygric conditions. Each plot includes three vegetation quadrats (2x2m) on both ends and in the middle of the plot.

• Investigation of long-term changes in coastal meadow plant communities: natural succession, effects of management practice (mowing, spring burning, introduction of wild cows).
• Investigation of grass-dwelling arthropod communities as an indicator of the state of coastal meadow ecosystems.

• Meadow plant community structure and species diversity.
• Soil characteristics.
• Abundance and species diversity of grass-dwelling arthropods mainly Diptera and Coleoptera.

• Plant communities within the permanent quadrats are described by using Braun-Blanquet five-level cover scale in midsummer.
• Grass-dwelling arthropods are collected by entomological sweep-net method 50 sweeps per plot 3 times per season.

Preliminary data show that insects are more sensitive indicators of environmental conditions than plants.