Allelopathic potential and cytostatic activity of Antarctic moss Sanionia georgicouncinata (Amblystegiaceae)

From the first half of the XX century, the maritime Antarctic was a region with high regional warming rates. At the beginning of the XXI century, regional warming strongly slowed down, but during the next twenty years the near-surface temperatures and mean annual precipitation at the Antarctic Peninsula will most probably increase. Higher temperatures and precipitation make the conditions in the maritime Antarctic more favourable for plants, including invasive species. Moreover, the increasing number of Antarctic tourists unintentionally transport thousands of seeds to the Antarctic on their clothes and equipment. In such circumstances, it is important to evaluate possible defensive mechanisms of native plant species, including their allelopathic potential. The objective of this study was to evaluate the allelopathic potential and cytostatic activity of Sanionia georgicouncinata. This species is widespread in the maritime Antarctic and is one of the most abundant moss species on the Argentine Islands (Wilhelm Archipelago). Seeds of cucumber Cucumis sativus, radish Raphanus raphanistrum subsp. sativus, wheat Triticum vulgare, and amaranth Amaranthus paniculatus were used as bioassay species. Fresh green biomass of S. georgicouncinata was used to prepare aqueous extracts with 1 : 10, 1 : 50, and 1 : 100 plant to water ratios. The average root length of wheat sprouts and cucumber sprouts in distilled water did not differ significantly from those in plant extracts. The root length of radish sprouts in 1 : 50 plant extract was significantly shorter than in distilled water. Meanwhile, in 1 : 50 and 1 : 100 water extracts, roots of amaranth plants were significantly longer than in water. The number of lateral roots of cucumber sprouts in water and studied aqueous extracts varied from 1 to 6 with medians from 3 to 4. The medians of control (distilled water) and sample groups (aqueous extracts) did not differ significantly, but only 38.1 ± 6.1% of cucumber sprouts developed lateral roots in the 1 : 10 aqueous extract of S. georgicouncinata, and even less – 28.3 ± 7.5% in the 1 : 50 aqueous extract. The results of this study show that the allelopathic potential of S. georgicouncinata is low. However, a significant cytostatic activity of the studied extracts shows that this species may still affect other plants and animals. Further research is needed to evaluate the impact of the studied extracts on root growth and germination of the invasive plants, particularly Poa annua

Wildlife population changes across eastern europe after the collapse of socialism

When political regimes fall, economic conditions change and wildlife protection can be undermined. Eastern European countries experienced turmoil following the collapse of socialism in the early 1990s, raising the question of how wildlife was affected. We show that the aftermath of the collapse changed the population growth rates of various wildlife taxa. We analyzed populations of moose (Alces alces), wild boar (Sus scrofa), red deer (Cervus elaphus), roe deer (Capreolus capreolus), brown bear (Ursus arctos), Eurasian lynx (Lynx lynx), and gray wolf (Canis lupus) in nine countries. Population growth rates changed in 32 out of 49 time series. In the countries that reformed slowly, many species exhibited rapid population declines, and population growth rates changed in 83% of the time series. In contrast, in countries with fast post- socialism reforms, many populations increased rapidly, and growth rates changed in only 48% of time series. Our results suggest that the direction and frequency of the changes were associated with socioeconomic conditions, and that wildlife populations can be greatly affected by socioeconomic upheavals

The peculiarities of bear numbers dynamics in the Eastern Carpatians

There have been two periods of change in the dynamics of bear population in the Eastern Carpathians. The first period lasted over 50 years, starting in the late 1940s and ending in the year 2001. The second period started in the early 21st century. The bear population reached its maximum- of about 1100 individuals - in the early 1970s. Over 85% of recorded bear deaths have resulted from poaching