Eastern Latvia Research Articles

Ground Beetles (Coleoptera: Carabidae) of Wheat Agrocenosis in Latvia

Species composition and zoogeographical peculiarities of ground beetles were studied in agrocenosis of a wheat field in the Jēkabpils district, Dignāja parish (eastern Latvia). A total of 8,683 specimens of carabids representing 41 species and 14 genera were recorded. Poecilus cupreus L. (36.08%), P. versicolor Strum. (23.93%) and Harpalus rufipes Deg. (18.27%) were eudominants. The group of dominants consisted of Pterostichus melanarius Ill. (5.81%) and Carabus cancellatus Ill. (5.01%). The prevailing forms were open area species (53.66%), mesophilous species (46.34%) and small zoophages (46.34%). Palaearctic species (36.58%) were the dominant zoogeographical element. The trappability peaked in June. Rare carabid species were recorded: Poecilus punctulatus Schall. (1 specimen) and Pterostichus macer (Marsham, 1802) (1 specimen).

ECOLOGICAL EXPEDITION AS EFFECTIVE FORM OF ENVIRONMENTAL RESEARCH AND ECOLOGICAL EDUCATION

The paper deals with ecological expedition as effective form of environmental research and ecological education. Since 1997 Rēzekne Higher education institution organizes ecological expeditions for study programme “Environmental engineering” students in the Eastern Latvia region. Students realize integrated assessment of environmental quality with different methods. Article summarize experience of 10- years long period. Also show main goals and tasks of ecological expeditions, describe field research methods and cameral processing of data.

Evaluation frameworks and conservation system of Latvian forests

Since the 1990s the forest conservation system in Latvia has developedin two parallel trends. This reflects both traditional application ofcentral European phytosociology by explicit forest communities (at least 19 associations inLatvian forests) and the recently appreciated method of key-habitats in forests.It consists of two attributes: indicator species–habitat specialists andcertain abiotic structures whose persistent presence on the spot is limited byintactness, time-scale and natural disturbances. Following the interpretationmanual of habitats in the European Union, eight forest habitats deserve particularconservation in Latvia. Altogether 8% of Latvian forests are formally protected,although only 1.5% meet the World Conservation Union Category ‘1’where all human intervention must be excluded or minimized. Original analysis ofLatvian forest communities by their phytosociological standard and a comparisonwith similar assemblages elsewhere suggest that four forest groups deserveall-European conservation priority in Latvia because of intactness and largestands still survived or because of narrow distribution area. These are:Alnus glutinosa–Betula spp.–Fraxinus excelsior wetlands (ca. 3000 ha invarious formal reserve networks), northern outposts of mixed riverine hardwoodforests on the bank slopes and in semi-permanently moist ravines (ca. 240ha in reserves), floodplain and riverine Quercusrobur relic woodlands in eastern Latvia (ca. 120 ha inreserves) and dry Fennoscandian–Baltic Pinussylvestris woodlands on dolomites and limestones (no areas formallyprotected by law yet). Preliminary inventory of woodland key-habitats suggeststhat only 3% of Latvian forests can meet the desired criteria. This method,based on 53 indicator species indicating certain habitat properties and 25abiotic structures and stand features, has been found a valuable tool inforestry practice to evaluate the forest before any logging takes place and tomonitor spatial changes of biodiversity.

Long-term and seasonal changes in chemical composition of surface waters in Latvia.

The changes of the chemical composition in Latvian inland waters over the last twenty years were determined. based on data of the National Monitoring Programme. Relationships between the water composition were studied. The chemical composition and seasonal change pattern depend a lot on hydrological factors which differed between eastern and western Latvia. Different pattern of long-term changes is found for substances which have different sources and sinks, at first for nutrients (decrease only in the last few years) and inorganic ingredients (commonly increasing trend). An attempt was made to identify the main sources of the major water ingredients and link changes of their concentrations with changes in loading to waters.

A Lower Cambrian shallow-water occurrence of the branching ‘deep-water’ type trace fossilDendrorhaphe from the Lontova Formation, eastern Latvia

We describe a unique Lower Cambrian (Lontova Formation, Latvia) occurrence of a branching trace fossil assigned toDendrorhaphe isp. In the Mesozoic and Cenozoic this type occurs exclusively in deep-water flysch deposits.Dendrorhaphe may, therefore, be an additional example of a flysch-type trace fossil with an origin in early Palaeozoic shallow-water environments and subsequent onshore-offshore displacement, or perhaps, expansion. Recently,Dendrorhaphe Seilacher 1977, has been synonymized withDendrotichnium Farres 1967 andUbinia Grosshejm 1961. This needs further consideration, especially because of possible relation of these ichnogenera toChondrites patulus Fischer-Ooster 1858.