In Germany, the Dryopteris affinis complex has its main distribution in southern parts of the country, but also occurs in the Harz Mountains, the northernmost German low mountain range. From 2008 to 2018, the authors made a series of excursions into the Harz Mountains to study this group. To cor-rectly identify the taxa, samples were collected for flow cytometric analyses as well as micro- and macromorphological examinations. The following taxa and cytotypes were detected: D....

AIMS We examined differences in lifespan among the dominant tree species (spruce (Picea abies (L.) H. Karst.), fir (Abies alba Mill.), beech (Fagus sylvatica L.), and maple (Acer pseudoplatanus L.)) across primary mountain forests of Europe. We ask how disturbance history, lifetime growth patterns, and environmental factors influence lifespan. LOCATIONS Balkan mountains, Carpathian mountains, Dinaric mountains. METHODS Annual ring widths from 20,600 cores from primary forests were used to estimate tree life spans, growth trends,...

Aim: Alpine habitats support unique biodiversity confined to high-elevation areas in the current interglacial. Plant diversity in these habitats responds to area, environment, connectivity and isolation, yet these factors have been rarely evaluated in concert. Here we investigate major determinants of regional species pools in alpine grasslands, and the responses of their constituent species groups. Location: European mountains below 50ºN. Time Period: Between 1928 and 2019. Major Taxa Studied: Vascular plants. Methods: We compiled species...

Депопулацията и стареенето на населението са основните фактори, които предопределят изменението на демографската ситуация в България през последните три десетилетия. Цел на настоящата разработка е да се изследва въздействието на синергията на тези негативни процеси върху развитието на страната посредством измененията в повъзрастовото разпределение на цялото население и населението в трудоспособна възраст за страната и по общини. Обект на изследването са взаимовръзките между средногодишните темпове на изменение на броя на населението на българските общини и...

For externally fertilising organisms in the aquatic environment, the abiotic fertilisation medium can be a strong selecting force. Among bony fishes, sperm are adapted to function in a narrow salinity range. A notable exception is the family Gobiidae, where several species reproduce across a wide salinity range. The family also contains several wide-spread invasive species. To better understand how these fishes tolerate such varying conditions, we measured sperm performance in relation to salinity from a...

The unique aquatic Pontocaspian (PC) biota of the Black Sea Basin (BSB) is in decline. The lack of detailed knowledge on the status and trends of species, populations and communities hampers a thorough risk assessment and precludes effective conservation. This paper reviews PC biodiversity trends in the BSB ( Bulgaria, Romania, Moldova, Ukraine and Russia) using endemic molluscs as a model group. We aim to assess changes in PC habitats, community structure and species distribution...

The river streamflows analyses can be successfully used in water resource planning and management, depending on the needs of the wide range users. It is possible to use these applications in several general directions: as informal, qualitative guidance for water managers, stakeholders and decision makers and prediction about long-term drought variability; for quantitative assessments of longterm hydrologic variability and assessment the severity and duration of drought cycles; as direct inputs into hydrologic models of a...