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Biologiczna specyfika traw rozłogowych w warunkach wieloletniego intensywnego użytkowania agrofitocenoz

Zezmer N., Orlienkova J.

Woda-Środowisko-Obszary Wiejskie

2013

T. 13, z. 1

183--190

W pracy przedstawiono doświadczalnie potwierdzone możliwości wieloletniego, produkcyjnego użytkowania (w ciągu 15–26 lat) wielokośnych agrocenoz łąkowych (pratocenoz) założonych na bazie traw rozłogowych – stokłosy bezostnej (Bromus inermis Leyss.) i mozgi trzcinowatej (Phalaris arundinacea L.). Gatunki te charakteryzują się dużym potencjałem regeneracyjnym, ponieważ wykształcają system podziemnych pędów (rozłogów) systematycznie tworzących pączki wegetatywne (pędowe). Całkowita długość rozłogów stokłosy wynosiła 70,5, a mozgi 89,3 m ·- ². Zawierały one odpowiednio 2627 i 2830 szt ·m- ² pączków wegetatywnych. Założenie i trzykośne użytkowanie wieloletnich agrocenoz łąkowych zapewniło duże plonowany, wynoszące 7,7–8,7 t s.m. i 75,2–83,3 GJ energii metabolicznej z hektara i równocześnie uzyskanie wysokiej jakości biomasy do przygotowania kiszonki i sianokiszonki, zawierającej 9,6–9,8 MJ ·kg- ¹ s.m. energii metabolicznej. W wyniku systematycznego wieloletniego produkcyjnego użytkowania agrofitocenoz 4–5-krotnie obniżono nakłady poniesione na założenie łąki w stosunku do standardowych.

The paper presents experimentally confirmed possibilities of long-term (15–26 years) productive use of multiple cut meadow agrocoenoses based on stoloniferous grasses – the smooth brome grass (Bromus inermis Leyss.) and the reed canary grass (Phalaris arundinacea L.). The species are characterised by a high regeneration potential since the develop the system of underground rhizomes (stolons) systematically producing vegetative buds. The total length of stolons of the bromegrass was 70.5 and those of the reed canary grass – 89.3 m ·m-². They contained 2627 and 2830 vegetation buds per square metre, respectively. Set up and the threefold cut of long-term meadow agrocoenoses ensured high yielding of 7.7–8.7 t dry mass and 75.2–83.3 GJ of metabolic energy per hectare with a possibility of obtaining high quality biomass for ensilage and hay silage containing 9.6–9.8 MJ ·kg- ¹ dry mass of metabolic energy. As a result of systematic long-term use of agro-phytocoenoses the inputs to meadow set up were 4–5 times smaller compared with the standard.

Illecebrum verticillatum L. - endangered species in agrocenoses of Eastern Poland : assessment of ecological and genetic indicators for protection goals

Skrajna T., Kubicka H., Rzymowska Z.

Polish Journal of Ecology

2012

Vol. 60, nr 3

577-589

A rapid decrease in floristic biodiversity of agrocenoses has been observed in Europe for a half of century. A dynamic intensification of processes of crop production is considered one of the major reasons for shrinking of occurrence acreage and population number, or even extinction of numerous species with narrow ecological niche and high sensitivity to herbicides. These unfavourable transformations contribute to the gene pool restriction and necessity of species conservation. A representative of that group of plants is Illecebrum verticillatum (Caryophyllaceae) - a rare species endangered due to extinction in many European countries. Results of a study on decline of communities with Illecebrum verticillatum at the most northeastward sites in the Kałuszyn Upland (Podlasie Lowland, Eastern Poland) are presented. Observations were made on permanent plots for three periods (I - the years 1994-1997, period II - the years 2002-2004 and period III - the years 2008-2010) over the last 17 years. The material studied consisted of 136 phytosociological releves made by Braun-Blanquet method. Changes in phytocenoses with Illecebrum verticillatum were analysed and the habitat factors responsible for regression of these phytocenoses were identified. The degree of endangering of Illecebrum verticillatum in the area studied was evaluated on the basis of the frequency of occurrence, population abundance and genetic variation at the level of storage proteins in seeds by the modified SDS-PAGE method. Comparison of phytocenoses from different periods revealed a number of qualitative and quantitative differences. The number of sites of occurrence as well as population abundance of Illecebrum verticillatum have drastically decreased. Changes in the contribution of indicatory species (according to Ellenberg) were noted. In periods II and III a decrease in the contribution of hygrophilous and acidophilous species and an increase in that of nitrophilous species was observed. Significant changes in the structure of communities were confirmed by the calculated similarity indices (the most pronounced differences were observed between periods I and III). The phytocenoses were transformed towards degraded floristic composition, manifested by a decrease in the number of species in a plot, decrease in species diversity and increase in the index of domination. A significant increase in pH and nitrogen content at the habitats studied was noted. The phytocenoses reveal a replacement of nitrophilous for the eurytopic species. The factors having the strongest restricting effect on the occurrence of communities with Illecebrum verticillatum in the areas studied include: changes in the structure of agricultural use of land, increase in the contribution of maize in the structure of crops and intensification of production. At present 6 sites with Illecebrum verticillatum remain in the study area about 260 km2 (Kałuszyn Upland, Central-eastern Poland). Electrophoretic analysis of storage proteins in seeds of this species from these sites has shown high genetic similarity of these populations, irrespective of the distances between them (0-19% diversity among six the remaining populations). The diminished genetic pool of Illecebrum verticillatum population in this area indicates a need for the protection of this species.