Propagation of Ajuga reptans L.‹Atropurpurea› by leaf cutting was studied with the aim of increasing the efficiency of the nursery plant production. The conditions for root formation were revealed using an incubator. The optimum temperature for root fomation was 20-25°C. Above 2500 lx of light intensity were needed to achieve the sufficient amount of root formation. The leaf cuttings were stored up to four weeks in darkness at 0-5°C. The roots developed not only from a whole leaf but also from the edge of the top half as well as the lower half of the leaf. When the cuttings were planted in pots with fertilizer and placed outside, they grew to 14 cm in diameter. The growth of the leaf cuttings was investigated by planting them in a pot with fertilizer under field conditions. The optimum season for planting of cuttings was June or July. When the cuttings were potted during this season, they grew to about 10 cm in diameter and could then be transplanted in a field. When two leaf cuttings were potted, the percentages of rotted cuttings was decreased and the growth increased by about two times that of one leaf cutting.

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Along the upper reaches of the Furano River and the Nukkakushifurano River, originating at Mount Tokachi and Mount Furano in Central Hokkaido, the natural recovery of trees is usually observed in the stony areas, but areas devastated after the construction of check dams have been very difficult to revegetate. Therefore, the revegetation processes were examined at four sites where rock fragments are distributed differentially according to size and volume. The stony sites had a greater stand density and taller trees than the site which was almost bare, and the site with boulders (20-40 cm in diameter) had taller trees than the site with cobbles (10-20 cm in diameter). Secondly, the soil temperature and the soil moisture pF values were measured at six sites where stone-mulching has occurred in different ways. The bouldered sites had smaller fluctuations in soil temperature than the cobbled ones. In laboratory experiments it was found that the boulders acted as heat insulators. The pF value of the surface soil during the dry period was negatively affected by the stone-mulching percentage in the field. This shows that stone-mulching has a negative effect on evaporation. Finally, these results suggest that a higher percentage of mulching with boulders produces better conditions for natural revegetation.

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The effects of ammonium and nitrate as the nitrogen source on concentration of NO₃--N, NH₄+-N, amino acids, protein, carbohydrates and site of nitrogen assimilation were studied in Nerium oleander L. under NaC1 salinity. Plants were grown in semi automatic sand culture system in the green house. We distinguished different distribution of carbohydrates and amino acids by nitrogen source under salinity. Ammonium and amino acids concentration increased in roots of ammonium treatment by salinity whereas protein concentration decreased. The level of carbohydrates decreased in leaves and increased in roots by salinity in ammonium treatment. No significant change in level of amino acids and carbohydrates was observed in nitrate treatment due to salt stress. Based on concentration of NO₃--N, NH₄+-N in xylem sap, glutamine synthetase and nitrate reductase activity, nitrogen assimilation was mostly done in roots and leaves in ammonium and nitrate treatments respectively. The lower tolerance of ammonium fed plants than nitrate is mostly related to higher diversion of carbohydrates from structure production to roots for ammonium detoxification and osmotic adjustment in ammonium fed plants under salinity.

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Investigations were carried out to determine the dynamics of vegetation around the Ili river delta, an arid zone in Kazakstan, using 5 year chronological data of NOAA LAC satellite images obtained in summer. From necessity to take reflectances of background soils into account when estimating vegetation amount in arid zones, soil reflectances of the different soil types were measured from 22 points. TSAVI values from the soil lines were calculated to describe the properties of each of the soil types. Vegetation dynamics was then determined through regression analysis of chronological data of the generated LAI images of Ili delta. From the results, it was clarified that vegetation distribution along the Ili delta was affected by allocation and fluctuation of flow along Ili river branches but not by precipitation during the dry season. Wide differences were also observed in the response pattern of “precipitation dependent” and “river and underground water dependent” vegetation with respect to flow fluctuation along Ili river branches. It was confirmed that vegetation decline in Ili delta was caused by water diversion for large scale irrigation purposes, and decrement of flood frequency due to the water flow regulation on the dam was increasing risk of the desertification.

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