Ecological And Cenotic Analysis Of Wild Relatives Of Cultivated Plants Of The Republic Of Karakalpakstan And Khorezm

The results of ecological and cenotic analysis of wild relatives of cultivated plants (DRC) of the Republic of Karakalpakstan and Khorezm are presented. Based on the classification of P. V. Kulikov (2005), a system was developed, where 8 ecologo-cenotic groups of DSCS were identified, and the resulting groups were divided into 16 subgroups. Ecological-cenotic analysis showed that the DSCS of the Republic of Karakalpakstan and Khorezm are mainly plants of deserts and meadows (58.5%). However, a significant share (19.9%) is made up of species with a narrow ecological amplitude, confined to specific habitats: saline soils and coastal (coastal and coastal-meadow). Desert-tope species are among the most vulnerable, 12 of which need to be preserved also because 3 of them are endemic and one is a relict species, which, due to their adaptation to extreme environmental conditions, can contain valuable genetic information.

Modern Pollen Rain and Vegetational History of the Malaspina Glacier District, Alaska

Seventy surface pollen samples from coastal forest, coastal meadow, muskeg, tree line, and alpine tundra communities form a basis for interpreting fossil pollen assemblages in the Malaspina Glacier district, Alaska. Poflen and macrofossil analyses of three radiocarbon-dated fossil sections from Icy Cape indicate that vegetational changes resulting from plant succession can be distinguished from those of migrational and climatic origin. Vegetation of the early Holocene xerothermic interval (10,000–7600 yr B.P.) was dominated by Alnus communities. Wetter conditions ensued, enabling generative muskeg surfaces to develop and first Picea sitchensis, then Tsuga heterophylla to expand from areas southeastward. Climatic cooling in more recent millennia (3500 yr B.P. to the present) is indicated by the appearance and persistent growth of Tsuga mertensiana and Selaginella selaginoides along this portion of the Gulf of Alaska coastline.