Lepidium subcordatum Botsch. et Vved. (Brassicaceae) is a rare endemic species of relict mountains of the Kyzylkum desert. The plant is listed in the “Red Data Book of Uzbekistan”. It grows on stony and rocky slopes...Lepidium subcordatum Botsch. et Vved. (Brassicaceae) is a rare endemic species of relict mountains of the Kyzylkum desert. The plant is listed in the “Red Data Book of Uzbekistan”. It grows on stony and rocky slopes of relict mountains. The ontogenetic structure of five coenotypical populations of this taxa growing in the Kuldzhuktau and Auminzatau mountains had been revealed. The ontogenesis duration is more than 20 years in natural habitats. All investigated coenopopulations can be assessed as normal and incomplete. The typical spectrum of coenopopulations is centralized with a peak in the middle-generative individuals. The ontogenetic spectrum of the most studied coenopopulations coincides with the characteristic ontogenetic structure that indicates a favorable environmental condition in region for self-maintenance of L. subcordatum coenopopulations.展开更多
The ontogenesis of the form Biota orientalis compacta (Cupressaceae) was first studied in the conditions of introduction of the Tashkent Botanical Garden. The passage of periods and stages of ontogenesis, full ripenin...The ontogenesis of the form Biota orientalis compacta (Cupressaceae) was first studied in the conditions of introduction of the Tashkent Botanical Garden. The passage of periods and stages of ontogenesis, full ripening of the cones, a high rate of growth and development, as well as high seed productivity are the main indicators of the success and prospects of the introduction of the form Biota orientalis compacta. The data obtained will serve as a theoretical basis for the agrotechnical development in landscaping.展开更多
A new salty and sandy desert of ca 5 million ha has emerged on the exposed Aral Sea bed. Every year, 170-200 tons of salt and dust rise into the air and fall on the territory of the Republic of Karakalpakstan. A numbe...A new salty and sandy desert of ca 5 million ha has emerged on the exposed Aral Sea bed. Every year, 170-200 tons of salt and dust rise into the air and fall on the territory of the Republic of Karakalpakstan. A number of experiments have been cond.ucted in order to study the salt tolerance of plants and select drought- and salt-resistant plant species, which show a wide ecological range, to fix quick-sand dunes on the exposed Aral Sea bed. Among the studied species of Calligonum genus C. caput-medusae Schrenk was the most resistant to the saline solution. At the end of the vegetation experiment, the survivability of individuals constituted 44.1% at the concentration of 1.0% of sodium chloride. Artemisiaferganensis Krasch. ex Poljak. and Salsola richteri （Moq.） Kar. ex Litv. showed a good resistance to the concentration of saline solution as high as 150 ram, at which no dried plants were recorded. As the concentration grew to 300 mM, the survivability of Artemisiaferganensis dropped to 40.0% while 66.7 Salsola richteri individuals were developing successfully. An almost similar result was obtained during the experiment on Nitraria schoberi L.. The survivability ofKrascheninnikovia ewersmanniana （Stschegl. ex Losinsk.） Grub. individuals significantly decreased at the concentration of 200 mm （33.4%）, while for Agropyron cristatum the concentration of 300 mm was threshold, at which the survivability of individuals was below 3.3%. The most resistant to the deflation of sands on the exposed bed were Salsola richteri and Calligonum caput-medusae, whose survivability on the sandy dunes was 17%-41%.展开更多
文摘Lepidium subcordatum Botsch. et Vved. (Brassicaceae) is a rare endemic species of relict mountains of the Kyzylkum desert. The plant is listed in the “Red Data Book of Uzbekistan”. It grows on stony and rocky slopes of relict mountains. The ontogenetic structure of five coenotypical populations of this taxa growing in the Kuldzhuktau and Auminzatau mountains had been revealed. The ontogenesis duration is more than 20 years in natural habitats. All investigated coenopopulations can be assessed as normal and incomplete. The typical spectrum of coenopopulations is centralized with a peak in the middle-generative individuals. The ontogenetic spectrum of the most studied coenopopulations coincides with the characteristic ontogenetic structure that indicates a favorable environmental condition in region for self-maintenance of L. subcordatum coenopopulations.
文摘The ontogenesis of the form Biota orientalis compacta (Cupressaceae) was first studied in the conditions of introduction of the Tashkent Botanical Garden. The passage of periods and stages of ontogenesis, full ripening of the cones, a high rate of growth and development, as well as high seed productivity are the main indicators of the success and prospects of the introduction of the form Biota orientalis compacta. The data obtained will serve as a theoretical basis for the agrotechnical development in landscaping.
文摘A new salty and sandy desert of ca 5 million ha has emerged on the exposed Aral Sea bed. Every year, 170-200 tons of salt and dust rise into the air and fall on the territory of the Republic of Karakalpakstan. A number of experiments have been cond.ucted in order to study the salt tolerance of plants and select drought- and salt-resistant plant species, which show a wide ecological range, to fix quick-sand dunes on the exposed Aral Sea bed. Among the studied species of Calligonum genus C. caput-medusae Schrenk was the most resistant to the saline solution. At the end of the vegetation experiment, the survivability of individuals constituted 44.1% at the concentration of 1.0% of sodium chloride. Artemisiaferganensis Krasch. ex Poljak. and Salsola richteri （Moq.） Kar. ex Litv. showed a good resistance to the concentration of saline solution as high as 150 ram, at which no dried plants were recorded. As the concentration grew to 300 mM, the survivability of Artemisiaferganensis dropped to 40.0% while 66.7 Salsola richteri individuals were developing successfully. An almost similar result was obtained during the experiment on Nitraria schoberi L.. The survivability ofKrascheninnikovia ewersmanniana （Stschegl. ex Losinsk.） Grub. individuals significantly decreased at the concentration of 200 mm （33.4%）, while for Agropyron cristatum the concentration of 300 mm was threshold, at which the survivability of individuals was below 3.3%. The most resistant to the deflation of sands on the exposed bed were Salsola richteri and Calligonum caput-medusae, whose survivability on the sandy dunes was 17%-41%.
