Phenological observations on Larix principis-rupprechtii Mayr. in primary seed orchard

Through 5 years of phenological observations on Larix principis-rupprechtii Mayr. in primary seed orchard and studies on population and individuals of clones, the annual periodic phenological laws were revealed and the annual phe-nological periodic table was drawn up. The correlation between various phenophases, the air temperature and active accumu-lated temperature were analyzed and expounded. The authors also analyzed the similarities and differences of phenophases among clonal individuals as well as the blooming properties of male and female flowers at the same time. This study could pro-vide theoretical reference for working out the production plan of improved varieties and other management measures in seed orchard of Larix principis-rupprechtii.

Analysis of the State of Woody Plants in the City of Nukus (Streets of Ernazar Alakoz)

This article observed seven species of Fraxinus excelsior L., Fraxinus pensylvanica March., Salix alba L., Populus alba L., Juniperus communis L., Catalpa bignonioides Walt., Ulmus densa Litv for seasonal growth. The Republic of Karakalpakstan is located in the North-West of Uzbekistan, covers 166,600 km2 (28%), and is the largest in terms of territory by region. The study of woody plants in the flora of Karakalpakstan is an important aspect of the convention on biological diversity. The species composition of the natural flora of Karakalpakstan is quite poor in ornamental plants, especially evergreens, suitable for gardening. At the same time, the biodiversity of these plants in Nukus and the factors contributing to them were analyzed. Relevance of the study: Creating an environmentally friendly environment in cities is possible by optimizing intra-urban tree plantations that perform forming, improving and regulating functions in the environment. The effectiveness of green spaces mainly depends on the range of trees and shrubs and their correct use in accordance with biological characteristics, environmental requirements and decorative qualities. The degree of impact of plantings on the environment also depends on the type, age and physiological characteristics of plants [1]. Woody plants, unlike hardwoods, enrich and purify the air throughout the year and can be used for single and group planting when creating hedges and borders, as well as green gardens. All year round, they enrich the air with oxygen, absorb street noises, and lower the air temperature. However, the conservation of flora is necessary not only for individual components, but also for the entire population diversity. Salinized land, unfavorable climate and other environmental factors are among the obstacles or restrictions to the introduction of new species of trees and shrubs, especially evergreen ones, in arid areas [2] [3]. The urban environment differs from the natural environment in terms of the degree of illumination, the amount of solar radiation, air temperature and humidity, soil properties, etc. In this regard, green plants only with proper planning, selection of assortment, sufficient quantity and good care ensure the improvement of the ecological state of the city. For scientifically based gardening, it is necessary to have objective ideas not only about the quantity and quality of existing plantings, but also to know the ecological and physiological state of each species, which allows us to assess the role of plants in improving the quality of the environment [4]. The sharply continental climate, aridity of the territory, increased wind activity and salinity of the soil contribute to the aggravation of environmental problems in the cities of the southern Aral sea region. The deteriorating environmental situation in Nukus requires the development of a specific gardening strategy aimed at creating sustainable urban plantings of various types. In this regard, we conduct research on the biological characteristics of ornamental woody plants in urban conditions. The range of tree and shrub species used in the landscaping of the city of Nukus remains quite poor today [5]. The predominant tree species are P. alba L., P. nigra L., P. diversifolia L., F. excelsior L., F. pensylvanica Marsh., Fraxinus potamaphylla Herd, S. excels S. Gmel, S. babylonica L., S. alba L., Juniperus communis L. In the landscaping of Nukus, introduced plants are also used, which have adapted to local conditions, although they are damaged by frosts. These include C. bignonioides Walt, Ulmus pumila L., F. pensylvanica Marsh.

Uncertainty in Simulating the Impact of Cultivar Improvement on Winter Wheat Phenology in the North China Plain

The phenology model is one of the major tools in evaluating the impact of cultivar improvement on crop pheno-logy. Understanding uncertainty in simulating the impact is an important prerequisite for reliably interpreting the ef-fect of cultivar improvement and climate change on phenology. However, uncertainty induced by different temperat-ure response functions and parameterization methods have not been properly addressed. Based on winter wheat phen-ology observations during 1986-2012 in 47 agro-meteorology observation stations in the North China Plain （NCP）, the uncertainty of the simulated impacts caused by four widely applied temperature response functions and two para- meterization methods were investigated. The functions were firstly calibrated using observed phenology data during 1986-1988 from each station by means of two parameterization methods, and were then used to quantify the impact of cultivar improvement on wheat phenology during 1986-2012. The results showed that all functions and all para-meterization methods could reach acceptable precision （RMSE 〈 3 days for all functions and parameterization meth-ods）, however, substantial differences exist in the simulated impacts between different functions and parameteriza-tion methods. For vegetative growth period, the simulated impact is 0.20 day （10 yr）^-1 [95% confidence interval： -2.81-3.22 day （10 yr）^-1] across the NCP, while for reproductive period, the value is 1.50 day （10 yr）^-1 [-1.03-4.02 day （10 yr）^-1]. Further analysis showed that uncertainty can be induced by both different fimctions and parameteriza-tion methods, while the former has greater influence than the latter. During vegetative period, there is a significant positive linear relationship between ranges of simulated impact and growth period average temperature, while during reproductive period, the relationship is polynomial. This highlights the large inconsistency that exists in most impact quantifying functions and the urgent need to carry out field experiment to provide realistic impacts for all functions. Before applying a simulated effect, we suggest that the function should be calibrated over a wide temperature range.