Šilagėlės genties augalai yra nepaprastai gražūs, dekoratyvūs ir puošnūs, bet kai kurios šilagėlių rūšys sparčiai nyksta, todėl yra saugomos įvairių teisės aktų pagalba. Lietuvoje augančios pievinė (Pulsatilla pratensis) ir vėjalandė šilagėlės (P. patens) savo paplitimo arealuose yra nykstantys augalai. Vėjalandė šilagėlė dėl spartaus nykimo Europos mastu, visose šalyse kuriose ji paplitusi, yra įrašyta į saugomų rūšių sąrašus ir juose dažniausiai priskiriama prie išnykstančių ar pažeidžiamų rūšių kategorijų. Pievinė šilagėlė nėra taip sparčiai nykstantis augalas, todėl Europoje yra priskiriama endeminėms rūšims (PILT, KUKK, 2002). Siekiant parengti geras rekomendacijas šilagėlių apsaugai, kurios jas įgyvendinus duos teigiamus rezultatus, pirmiausia yra būtina surinkti visus įmanomus duomenis apie šią rūšį. / The genus Pulsatilla includes perennial plants of the Ranunculaceae family. In Lithuania this genus is represented by two species and one hybrid: P. patens, P. pratensis and P. ×wolfgangiana. P. patens is endangered throughout Europe and is included into the Red Data Books of almost all European countries. Endemic species of Europe P. pratensis is included into the Red Data book just in several European countries. P. ×wolfgangiana is very rare hybrid species, occurring in areas where both parental species occur together. The aim of this work was to estimate composition and state of populations of the genus Pulsatilla in Lithuania. The tasks of the work are as follows: 1) to reveal plant communities in which members the genus Pulsatilla grow; 2) to evaluate structure of populations according to stages of plant maturity; 3) to investigate density of P. patens and P. pratensis individuals in populations; 4) to compare variation of Pulsatilla morphological characters and their dependence on habitat conditions; 5) to evaluate optimum habitat conditions for Pulsatilla populations in Lithuania. Results of the research enable to reveal composition and state of populations of the genus Pulsatilla in Lithuania and to prepare recommendations for management of their habitats.

Salinity is a major abiotic stress in plant agriculture which reduces seed germination, vegetative growth, and flowering, and limits crop productivity world-wide. Salinity causes water deficit, ion toxicity, and nutrient deficiency in plants, which can result in cellular damage, growth reduction, and even death. Kentucky bluegrass (Poa pratensis L.) is the most widely used cool-season species in cool-arid climates; however it has relatively poor salt-tolerance. Thus the development of Kentucky bluegrass genotypes with increased salt tolerance is of interest to turf breeders. One impediment to selection towards this goal is finding an efficient and accurate method to evaluate the salt tolerance. The objective of this study was to examine physiological responses to salt stress and to evaluate the genetic diversity among the accessions used in the research. Salt-tolerant accessions PI371768 (768) and PI440603 (603) and salt-sensitive varieties Midnight and Baron were exposed to four levels of salinity imposed by irrigating with salt solutions of 0 dS m-1 (control), 6 dS m-1, 12 dS m-1, and 18 dS m-1 or 24 dS m-1. Soil salinity was measured using Acclima Digital TDT sensors and grass response to the stress was measured using turf quality ratings, stomatal conductance, leaf water potential and electrolyte leakage. In general, turfgrass quality, stomatal conductance, and leaf water potential decreased while electrolyte leakage increased under salinity stress. Midnight and Baron exhibited greater changes in these measurements, indicating more sensitivity compared to 768 and 603. The 6 dS m-1 treatment had little effect on the salt-tolerant accessions. Salt tolerance of 603 and 768 was confirmed and likewise, salt sensitivity of Baron and Midnight was confirmed. The genetic similarity of all cultivars used in this study was very high. All of the evaluation measurements were highly correlated, with water potential and electrolyte leakage being the most reliable and accurate methods due to the low standard deviations. Due to more repeatable methods and less user error, electrolyte leakage and turfgrass quality are recommended methods for screening salt tolerance of turfgrasses.

No description available.

Interspecific aggression of meadow pipit (Anthus pratensis) towards treepipit (A. trivialis), whinchat (Saxicola rubetra) and skylark (Alauda arvensis) and interspecific aggression of whinchat towards meadow pipit was tested in playback experiments at the beginning of breeding cycle (both species) and during the brood feeding period (whinchat only). Neither meadow pipits nor whinchats responded aggressively to the playback of the heterospecific songs. Whinchats, however, chased or attacked meadow pipits that approached it in response to the meadow pipit songs in the brood feeding period. I suggest that the aggressive behaviour in whinchat is triggered rather by visual than acoustic cues. Another series of playback experiments with meadow pipits was carried out to investigate the effect of the sensitisation caused by previous playback of the conspecific song on performance during the playback of the tree pipit song 30 minutes later. No clear effect was discovered, but some of meadow pipits reacted in a way more characteristic for the intraspecific experiments.

This study aims to get a better understanding of the oviposition-behaviour of the butterflyMarsh Fritillary (Euphydryas aurinia), in the area Bälsalvret on the Island of Gotland. Thestudy may provide helpful information to aid the conservation of the species in the area andalso provide overall knowledge about the female’s preferences when it comes to choosingmicrohabitat and host plant for their eggs.The analysis of the microhabitat preference for oviposition by the Marsh Fritillary showedthat eggs were predominantly laid on large-sized host plant individuals with a warmermicroclimate; with a preference for the rosette diameter, the length and the width of the leafand the number of Succisa pratensis individuals in the vicinity. This indicates that thefemale’s priority is to place the eggs at the most optimal place for their offspring’s survivaland growth.

La apertura del dosel del bosque generada por disturbios antrópicos o naturales provoca una alteración en las condiciones ambientales del sistema ecológico, modificando la cantidad y calidad de luz, las precipitaciones, y la temperatura. Los estudios realizados en este trabajo de tesis determinaron algunos de los cambios morfo-fisiológicos que permiten el crecimiento, desarrollo y reproducción de tres especies herbáceas, Osmorhiza depauperata, Phleum alpinum y Poa pratensis, en los ambientes boscosos modificados. Estas especies aumentan su cobertura luego de la cosecha forestal, y podrían evitar la erosión del suelo, y facilitar o competir con las plántulas que podrían contribuir a regenerar el bosque. En el bosque aprovechado forestalmente mediante la prescripción de retención variable se identificaron tres situaciones donde crecieron las plantas de las especies herbáceas: dentro de la retención agregada (RA), en el borde de la retención dispersa con influencia del agregado (BRA), y en la retención dispersa (RD). Además, se seleccionaron plantas del bosque primario (BP). Por otro lado, P. alpinum y P. pratensis fueron expuestas en el invernáculo a tres niveles de radiación incidente (I4: 4%; I26: 26%; I64: 64% de la luz solar incidente fuera del bosque en los diferentes ambientes), y dos niveles de contenido de humedad del suelo (M30: 30-50% y M60: 60-80% de capacidad de campo). Las intensidades lumínicas medidas siguieron el orden: RD > BRA > RA > BP. Las plantas de todas las especies modificaron su morfo-fisiología en los distintos ambientes. Estos cambios incluyeron modificaciones en el largo de las hojas, y por consiguiente su área foliar, aumentando en los ambientes con menor radiación (BP y RA). Asimismo, en estos ambientes disminuyeron el macollaje o la cantidad de tallos. Las plantas también incrementaron la densidad de longitud de raíces en respuesta al incremento en la disponibilidad de luz. Las diferencias entre especies se podrían deber a sus hábitos de crecimiento y a la proporción de raíces finas que producen. En O. depauperata el grado de infección por micorrizas vesículo-arbusculares fue mayor que en las especies de gramíneas P. alpinum y P. pratensis. Para todas las especies se encontró que el grado de infección tendió a incrementarse al aumentar la luz, aunque solo se encontró que fue significativamente menor en BP que en el resto de los ambientes. Todas las especies produjeron mayor cantidad de biomasa por unidad de superficie iv a medida que aumentó la irradiación: el orden de las especies estuvo inversamente relacionado con el tamaño del área basal, fue mayor en O. depauperata que en P. alpinum y P. pratensis. La cantidad de inflorescencias por unidad de área basal siguió la misma tendencia que la biomasa, y no se encontraron cambios en la proporción de inflorescencias por unidad de biomasa excepto en P. alpinum. En esta especie, esta variable fue menor en BP que en el resto de los ambientes. En P. pratensis el esfuerzo reproductivo fue mayor que en O. depauperata y P. alpinum. En invernáculo se demostró que la variable más importante que modificó el crecimiento de estas plantas fue la luz. El crecimiento disminuyó considerablemente en I4. Al disminuir la irradiación aumentó la proporción de área foliar, mediante un aumento del área foliar específica y un aumento de la proporción de biomasa foliar. Al mismo tiempo, aumentó la proporción de biomasa de tallo, y disminuyó la proporción de biomasa radical. Como resultado de estos cambios, las plantas en I26 lograron mantener una tasa de crecimiento relativa similar o superior a la de I64; sin embargo, dichos cambios no fueron suficientes para mantener la tasa de crecimiento relativa en I4. Asimismo, las especies mostraron cambios típicos a nivel fisiológico: al aumentar la irradiación aumentaron la tasa máxima de fotosíntesis y el punto de compensación lumínico. Se encontraron variaciones temporales que afectaron estos valores. Al aumentar la irradiación disminuyó el contenido de clorofila tanto por unidad de área como de peso fresco, y aumentaron las relaciones clorofila a/b y carotenoides/clorofila. Todos estos resultados indican que O. depauperata, P. alpinum y P. pratensis son capaces de aclimatarse a varias situaciones ambientales. Sin embargo, O. depauperata mostró una mejor capacidad de aclimatación a niveles de irradiación muy bajos, mientras que las especies de gramíneas apenas lograron sobrevivir dado que su crecimiento fue muy lento. / Canopy openings, whether they come from anthropic or natural disturbances, might change the environmental conditions of the ecological system, modifying light quantity and quality, precipitation and temperature. Some morpho-physiological changes that determine growth, development and reproduction of the three study herbaceous species, Osmorhiza depauperata, Phleum alpinum, Poa pratensis, were evaluated in the forest, modified environments. These species increase their coverage after forest harvesting, and could prevent soil erosion, and either facilitate or compete with seedlings that could contribute to regenerate the forest. Three environments where the herbaceous species often grow were identified in a forest previously harvested following the variable retention system. They were: within the aggregate retention (RA); on the edge of the dispersed retention under the influence of the aggregate (BRA), and dispersed retention (RD). Plants were also selected from a primary forest (BP). Furthermore, P. alpinum and P. pratensis were exposed to three levels of incident radiation (I4: 4%; I26: 26%, or I64: 64% of ambient sunlight outside the forest in the various environments) and two levels of soil moisture content (M30: 30-50% or M60: 60-80% of field capacity) under greenhouse conditions. Measured light intensities showed the following order: RD > BRA > RA> BP. Plants of all species modified their morpho-physiology in the different environments. These changes included variations in blade length, and subsequently in leaf area, increasing in the environments with lower radiation (BP and RA). Also, tillering and stem numbers decreased in these environments. Plant root length density increased as light availability also increased. Species differences could be due to their growth habits and the proportion of fine roots that they produce. Vesicular-arbuscular mycorrhizae colonization was greater in O. depauperata than in P. alpinum and P. pratensis. It also tended to decrease as light availability decreased for all species. However, it was only significantly lower in BP than in the remaining environments. Increased light availability determined a greater biomass production per unit surface area in all species: the species order was inversely related to size of the basal area. It was greater in O. depauperata than in P. alpinum and P. pratensis. The number of inflorescences per unit basal area followed the same trend as biomass and no changes were found in the proportion of vi inflorescences per unit biomass, except in P. alpinum. In this species, this variable was lower in BP than in the other environments. Reproductive effort was greater in P. pratensis than in O. depauperata and P. alpinum. Greenhouse experiments showed that light was the major variable that modified growth of the study species. Growth decreased significantly in I4. Increases in specific leaf area and the proportion of leaf biomass determined an increased proportion of leaf area under lower light availability. At the same time, stem biomass proportion increased and that of root biomass decreased. As a result of these changes, plant relative growth rate was similar or greater in I26 than in I64; however, they were not enough to maintain plant relative growth rate in I4. Also, the species showed typical physiological changes: maximum photosynthetic rate and light compensation point increased as light availability also increased. Values for these variables varied with time. Chlorophyll content per unit surface and fresh weight decreased, and chlorophyll a/b and carotenoid/chlorophyll ratios increased, as light availability increased. The results obtained in this study indicate that O. depauperata, P. alpinum and P. pratensis are able to acclimate to various environmental situations. However, O. depauperata showed a better acclimation capacity than the other species to very low levels of light availability, while the grass species just were able to survive under these conditions because of their very slow growth.

Vildbiet guldsandbi (Andrena marginata F.) har en central roll i jordbrukslandkapet som en viktig pollinatör av grödor och vilda växter. I Sverige hotas artens fortlevnad av biotopförlust, habitatfragmentering och födobrist. En av de viktigaste näringskällorna är växten ängsvädd (Succisa pratensis M.) som tidigare var vanligt förekommande men som nu minskar i sin utbredning. Syftet med denna studie var att utreda om populationsstorlekarna av guldsandbi och ängsvädd är relaterade. Guldsandbinas observationsbaserad populationsstorlek uppskattades samt att ängsväddens bestånd inventerades vid fyra lokaler i Övre Klarälvsdalen, i norra Värmland. Binas populationsstorlek uppskattades genom transektinventeringar mellan 30 juli och 11 augusti 2013. Under perioden observerades totalt 286 honor och per observationsdag noterades ett medelvärde på 40,86 (± 8,1 SE, 95% konfidensintervall; n=7) honor. Ängsväddpopulationen uppskattades till totalt 2328 växter från alla fyra områden. Det fanns inget statistiskt samband mellan populationsstorlekarna av ängsvädd och guldsandbin. En jämförelse mellan den för biet förväntade populationsstorleken, baserad på förekomst av näringsväxten, och den observerade populationsstorleken, korrigerad för inventeringsbias, visade bra överensstämmelse vid två av fyra områden (8,4% respektive 5,7% från det teoretiska värdet) och dålig överensstämmelse vid de andra två områdena. Det kan mycket väl vara så att det finns en relation mellan populationerna i Övre Klarälvsdalen, men man måste öka antalet lokaler och ta hänsyn till ytterligare miljöfaktorer som påverkar både bina och växterna för att kunna dra säkrare slutsatser om ett samband. / The wild-bee Andrena marginata has a key function as an important pollinator of crops and wild plants in agriculture landscapes. The species’ persistence is threatened in Sweden due to loss of habitat, fragmentation and food scarcity. One of the most important food sources is the plant Succisa pratensis, which previously was very common but now has declining populations. The purpose of this study was to analyse if there was a relation between the population sizes of A. marginata and S. pratensis. The population size of the bees was estimated and the plant population was surveyed at four sites in the upper valley of the River Klarälven, Värmland. Bee population size was estimated by visual transect surveys conducted between 30 July and 11 August 2013. In this period a total of 286 females was observed, with a mean of 40,86 (± 8,1 SE, 95% confidence interval; n=7) per day. The total population size of S. pratensis from the four sites was estimated to 2328 plants. There was no significant correlation between the population sizes of the bees and the host plant. A comparison between the bee’s predicted theoretical population size, based on the number of host plants, and the observed population size, corrected for observer bias, showed good agreement for two of the sites (within 8,4% and 5,7% of the theoretical value) and poor agreement at the other two sites. There may well be a relation between the bee and plant populations in the upper valley of Klarälven, but one needs to increase the number of sites and take into account additional environmental factors that affect both the bees and the plants to draw a firmer conclusion about such a relationship.

The purpose of the study was to provide further knowledge about if the total amount of solar radiation during the marsh fritillary’s (Euphydryas aurinia) period for larvae development (April 15th – May 15th) and/or flying period (June 1st – June 30th) influenced the average of larvae colonies in the autumn at 12 sites in Dalarna County. Among increased temperatures, global climate models also predict an increased amount of solar radiation and a decrease in cloudiness in northern Europe, as a result of the climate changes. The marsh fritillary has declined rapidly, especially in the Northern of Europe and are in Sweden red-listed as vulnerable (VU). The marsh fritillary is a univoltine species who are dependent on open, sunny, and moist semi-natural grasslands with the hostplant devil’s bit (Succisa pratensis). The data over solar radiation was received from SMHI and had been measured in Borlänge over the last 14 years. The data over the number of larvae colonies was received from Länsstyrelsen Dalarna and had been measured over the last 15 years. The linear regression analysis for both the period of larvae development (p=0,58) and the whole period (p=0,07) indicates that during those periods the solar radiation did not influence the average of larvae colonies. However, the total amount of solar radiation during the flying period (p=0,02) influence the average of larvae colonies during the autumn.

The genetic status of the critically endangered Mississippi sandhill crane (Grus canadensis pulla) was analyzed using 2009 studbook data from the U.S. Fish and Wildlife Service managed captive breeding and release program. Microsatellite DNA data provided information on shared founder genotypes, allowing for refined analysis of genetic variation in the population, and informed breeding recommendations. The genetic variation observed in the Mississippi sandhill crane was contrasted with variation observed in the Florida sandhill crane (Grus canadensis pratensis). Results show far less variation in the Mississippi population. Results also suggest that while gene flow no longer occurs between the two populations, the introduction of cranes from the Florida population would help to increase the observed genetic diversity of the Mississippi sandhill crane population.

Soil contamination with heavy metals is a problem of worldwide concern that is still unsolved. The analysis of the current methods of soil cleaning from heavy metals leads to conclusions that phytoremediation, i.e. soil decontamination by using plants, is one of the best methods. Although this method has not received a wide application yet and possibilities of its application are still being analysed, it is one of the most prospective soil cleaning methods due to low cost and a rather efficient cleaning of the upper surface of soil. Three kinds of Poaceae f. Species – Lolium perenne L., Poa pratensis L. and Festuca pratensis Huds. – have been chosen in this work for decontaminating soil from heavy metals. These plants were grown under artificial laboratory conditions in soil which was once and periodically contaminated with heavy metals. It was established that it is the Lolium perenne L. that most efficiently removes heavy metals and cleans soil. The results of experiments show that the selected grassy plants (perennial ryegrass, meadow-grass and fescue-grass) efficiently clean soil from heavy metals (copper, lead, manganese, zinc, nickel and chromium) when soil contains both low (0.5–120 mg/kg) and high (up to 6,850 mg/kg) concentrations of these metals. Since the perennial ryegrass absorbs the highest amount of heavy metals, the highest efficiency of soil cleaning is achieved using this plant, therefore, 80 % of the mixture of grassy plants was formed of the perennial... [to full text] / Dirvožemio tarša sunkiaisiais metalais visame pasaulyje aktuali problema iki šiol neturinti universalaus sprendimo. Išanalizavus šiuo metu dirvožemio valymui nuo sunkiųjų metalų naudojamus metodus, galima daryti išvadą, kad vienas iš tinkamiausių metodų yra fitoremediacija, t. y. dirvožemio valymas nuo teršalų panaudojant augalus. Šis metodas dar nėra plačiai taikomas ir jo taikymo galimybės dar tik tiriamos tačiau, tai vienas iš perspektyviausių dirvožemio valymo metodų dėl sąlyginai mažos kainos ir pakankamai efektyvaus paviršinio dirvožemio sluoksnio išvalymo. Atliktų eksperimentinių tyrimų rezultatai parodė, kad pasirinkta žolinė augalija – daugiametė svidrė, pievinė miglė ir tikrasis eraičinas efektyviai valo dirvožemį nuo sunkiųjų metalų (vario, švino, mangano, cinko, nikelio, chromo) tiek esant mažoms (0,5–120 mg/kg), tiek didelėms (iki 6850 mg/kg) jų koncentracijoms dirvožemyje. Kadangi daugiausiai sunkiųjų metalų iš dirvožemio sorbuoja svidrė, tai dirvožemio valymo efektyvumas naudojant šią žolinės augalijos rūšį yra efektyviausias ir sudarant žolinės augalijos mišinį 80  sudarė svidrė ir po 10  eraičinas bei miglė. Eksperimentų metu tirta, kaip sunkiųjų metalų mišinio koncentracijos kenkia hidrobiontams ir nustatyta, kad didinat sunkiųjų metalų mišinio koncentracijas (iki 0,198–5,12 g/l) jos tampa letalinėmis vaivorykštiniam upėtakiui, tuo pačiu ir kitiems vandens gyvūnams.Pagal tyrimų su vaivorykštiniais upėtakiais rezultatus nustatyta, kad stebimų... [toliau žr. visą tekstą]