Z. Karimian; N. Zarin
Abstract
Background and Objectives: Tulip flower is one of the most popular flowers in the world. This bulbous flower has about 150 species with more than 6000 recorded cultivars. In the recent years, planting of ornamental bulbous plants such as tulip has been common in many cities of Iran during Nowruz. ...
Read More
Background and Objectives: Tulip flower is one of the most popular flowers in the world. This bulbous flower has about 150 species with more than 6000 recorded cultivars. In the recent years, planting of ornamental bulbous plants such as tulip has been common in many cities of Iran during Nowruz. Selection and order of the bulbs often is done based on aesthetic and flowering factors. Feasibility of estimation of some aesthetic traits in tulip cultivars can be a management approach in the cities, so that if urban managers in the landscape field know the time and duration of flowering, they can have an exact plan for the tulip planting in the Nowruz. The study of ornamental traits, flowering date and duration of tulip flower have been studied in the different climatic and edaphic conditions. Tulip cultivars have prolong flowering periods that their flowering duration can match with Nowruz are an apocopate option to use in the urban landscape of Mashhad. One of the methods to estimate the vegetative and ornamental traits in the ornamental plants is prediction models using bulbous dimensions with other plant part dimensions or combinations of them. In the current paper the study of the date of flowering and its duration in the several cultivars was investigated. On the other hand an attempt has been made to establish a best method for estimation of some ornamental traits in the tulip flower.
Materials and Methods: In the first part of the examination, six plots including six cultivated cultivars of tulip with area of 5 m2 were prepared. Weight and diameter of bulbs were measured before planting and ornamental traits include height of flower stem, length and width of flower. Data from nearly 100 plants for each cultivar were recorded. Regression analyses of WB, DB, WB×DB, WB/DB, WB2×DB2 and WB2/DB2 versus height of flower stem, length and width of flower were done. . Among tested models (linear, polynomial, power, logarithmic and exponential) the models with highest R2 values can be used for estimating of the mentioned ornamental traits. The correlation coefficients and also constants (a, b and c) were reported. In the other part of the examination, 23 cultivars of tulip in 15 plots with area of 20 m2 were planted in the various parts of Mashhad. Flowering date and also the duration of flowering from nearly 50 plants for each cultivar were recorded.
Results: Results showed that the highest correlation between dimensions of bulbs (weight and diameter) with height of flower stem (R2=0.88) was observed in weight of bulbs. Among of the tested models , the highest coefficient of correlation was obtained in polynomial equation. The calculated correlation between weight and diameter of bulbs with length and width of flower were low. In the Royal virgin cultivar, flower length with the bulb weight and also multiple of the bulb weight and diameter significantly showed a positive correlation (R2=0.88 and R2=0.81). In the other part of the current study, results indicated that the most of studied cultivars showed different flowering dates and durations. According to the results, the most early-flowering cultivars obtained from Copex, Yokohama, Happy generation and Apricot beauty. The most lately-flowering cultivar of tulip in the present study was observed in Spring green.
Discussion: In the first part of the study, the developed models including WB, WB×DB and WB2×DB2 that have the highest R2 levels in comparison with other models can be applied to estimate height of flower stem in most of tulip cultivars. In the second part of the study, among of the 23 cultivars, only Apricot fox, Pretty lady, Happy generation and Yokohama are advisable to plant in the urban landscape in Mashhad in order to have flower during the Nowruz.
zahra karimian; Ali Tehranifar; Mohammad Bannayan; Majid Azizi; Fatemeh Kazemi
Abstract
Introduction: Considering population growth and urbanization development, one of the main requirements of the urban society is to create appropriate life condition for dwellers. The microclimate is considered as one of the factors that affect the activity of people in the environment and in terms of ...
Read More
Introduction: Considering population growth and urbanization development, one of the main requirements of the urban society is to create appropriate life condition for dwellers. The microclimate is considered as one of the factors that affect the activity of people in the environment and in terms of tourist and recreational industry, it is considered as an important source of economic. Many climatic parameters such as temperature, relative humidity, radiation and wind speed can affect the quality of people's recreational activities. So far, many studies have been conducted in the world about the positive effects of vegetation specially trees in the urban landscape on the optimizing of microclimate and human thermal comfort. The cooling mechanism of trees and clouds in an area mainly by directly shading the ground surface and indirectly by supplying humidity are similar. Thus, perhaps it be possible to calculate the changes in temperature and relative humidity based on cloud categories and impute it to tree canopy and vegetation size. The purpose of the present study was to answer followed questions, 1) does the use of single tree produce a sensible difference in temperature and humidity relative to open space? 2) Does the acacia tree as an indicator for a broad-leaved species compare to the pine tree as an indicator for the needle species in terms of the microclimatic variation of around themselves act differently? 3) Do the microclimatic elements (Temperature and relative humidity) under the canopies are comparable to various cloudiness conditions?
Materials and Methods: The experiments were conducted at Ferdowsi University of Mashhad. The climate data under two species of false acacia (Robinia pseudoacacia) and pine trees (Pinus eldarica) and open space were received from Mashhad weather station over a period of 19 years, recorded and analyzed. In the comparison of the effects of vegetation and cloudy conditions on the temperature and relative humidity an assumption was proposed that has been mentioned in the following. The differences between the means of temperature and relative humidity obtained under SKC (Sky Clear) cloudiness conditions and in open space; under SCT (Scattered Sky) conditions and pine trees; and under BKN (Broken Sky) conditions and false acacia tree must be equal or these differences must be statistically not significant. In addition to the effect of tree canopy, the effects of days and hours on the temperature and humidity were investigated. To analysis and also mean comparison, SPSS 16 software was used.
Results and Discussion: The results showed that the temperature (decreasing) and relative humidity (increasing) were significantly different among various cloudiness conditions during 19 years. The results also indicated that between the temperatures recorded under the canopy of pine and false acacia trees, and also among of recorded relative humidity in two trees specious with corresponding outdoor spaces there were significant differences. Also, there were no significant differences among the temperature of the clear sky and the partly cloudy with that of the mostly cloudy sky. Further, clear sky and mostly cloudy sky showed significant differences in terms of relative humidity. Mostly cloudy sky and the partly cloudy sky compared with pine and false acacia trees were about 4.6 and 4.5oC cooler, respectively. The cloud covers, also could enhance the more level of relative humidity in the environment in comparison with single tree canopy, so that were caused a wetter environment equal to16.6 and 8.4 percent, respectively. The results also showed that temperature and relative humidity created by the shade from false acacia and pine trees are not comparable with the same climatic factors created by partly cloudy and mostly cloudy skies. In the present study, false acacia as a broad-leaved tree compared with pine tree and also open space could cool the environment about 0.65 degree C more that is in line with previous studies that showed the microclimatic impact of vegetation depend on crown and leaf size. Temperature and relative humidity in vegetation (trees) and cloudy condition are not comparable with microclimate and their impact on the environment is not the same. The cloud covers, also could enhance the more level of relative humidity in the environment in comparison with single tree canopy, so that were caused a wetter environment equal to16.6 and 8.4 percent, respectively.
Conclusion: This finding showed that climatic effects of cloud covers had no similarity compared with two studied trees species. It may also indicate that green space and greenery should not also be ignored in areas where cloudy skies are mostly present throughout the year.
zahra karimian; ali tehranifar; Mohammad Bannayan; majid azizi; fatemeh kazmi
Abstract
Introduction: With regard to two adverse climatic phenomena of urban heat islands and global warming that has been leading to increase temperature in many cities in the world, providing human thermal comfort especially in large cities with hot and dry climates, during the hottest periods of the year ...
Read More
Introduction: With regard to two adverse climatic phenomena of urban heat islands and global warming that has been leading to increase temperature in many cities in the world, providing human thermal comfort especially in large cities with hot and dry climates, during the hottest periods of the year is crucial. Mainly vegetation with three methods: shading, evapotranspiration and wind breaking can affect micro-climate. The aim of this study was to asses and simulate the impact of existing and proposed vegetation on the human thermal comfort and micro climate changes in some residential areas of Mashhad during the hottest periods of the year by using a modeling and computer simulation approach.
Materials and Methods: This research was performed in the Ghasemabad residential area, Andisheh and Hesabi blocks, and in the hottest period of the year 2012 in Mashhad. Recorded data in the residential sites along with observed data from Mashhad weather station that included temperature, relative humidity, wind speed and direction. Soil data (soil temperature and humidity, soil\ type), plant data (plant type, plant height, leaf area index) and building data (inner temperature in the building, height and area buildings) as input data were used in the ENVI-met model. Both two sites, Andishe and Hesabi residential blocks, with vegetation (different trees and bushes plants, for example Acacia, ash, sycamore, mulberry, chinaberry, barberry, boxwood and Cotoneaster that all of them are tolerant and semi-tolerant to drought) about 20% were simulated. Regarding the area of simulating, 3 receptors were considered in per sites. Simulation was commenced from 6 AM and continued until 18 pm, but just data of 11-15 hours were analysed (the hours of peak traffic).
Results and Discussion: Analysis of outputs data revealed that the temperature of two residential sites in all three receptors during the study were almost the same. In general, the maximum temperature difference between receptors was obtained at 13 hour. The trend of relative humidity changes was very similar in both residential sites. In these two sites the most differences in the relative humidity was obtained at 12 oclock.. In addition, the trend of Predicted Mean Vote (PMV) in Andisheh residential block showed that these changes in central and south-west part of the site were similar. The simulation with vegetation in the sites, also, showed that the trend of temperature and relative humidity changes were similar. The trends of temperature changes in residential site, Hesabi, in the defined receptors were very similar. So that temperature increased from 12 oclock to 15. While the trend of relative humidity changes was quite the reverse. This study results showed that the difference in temperature, relative humidity and PMV between measured and simulated data were minimal in both residential sites. Moreover, the data comparison of PMV indicated that in both residential sites, despite of simulation with vegetation, the human thermal comfort did not improve, so that these sites were in the range of extreme heat stress. There are several reasons to justify this issue, such as the percentage and the type of vegetation, factors related to the topography and geography of area, building distribution and density, type and color of the building materials and surfaces, etc. However, in this part of the study, other factors were constant, except vegetation. It seems that with increase of percentage and the ratio of vegetation, changes in temperature, relative humidity and other micro-climate factors, are created, but sometimes for the reasons stated, the temperature during the hottest period of the year is too high so that increase in vegetation will have little impact on outdoor thermal comfort. It might be the simulated area on these sites as well as the type and the ratio of the selected species to reduce the temperature and increase the relative humidity have been not adequately represent all conditions which be able to improve thermal comfort.
Conclusions: In this study eventually we can conclude that in the simulated sites with about 20 percent vegetation cover,, despite the slight decrease and increase in temperature and relative humidity, respectively compared with the real sites, the thermal comfort range was similar. It is advisable in the future studies to simulate the green area in shape of the vertical and horizontal, changes in species composition in green area like trees, shrubs, and cover plants and also the test of different combinations of type and percentage of vegetation.
M. Shoor; Z. Karimian; M. Goldani
Abstract
In one side the negative effects of increasing of concentration of carbon dioxide in the world, and in the other side, the positive effects of greenhouse enrichment by such gas is one of the most important reasons in researching of this gas on different plants. For assessment of the effects of carbon ...
Read More
In one side the negative effects of increasing of concentration of carbon dioxide in the world, and in the other side, the positive effects of greenhouse enrichment by such gas is one of the most important reasons in researching of this gas on different plants. For assessment of the effects of carbon dioxide and light regimes in different genotypes of Pansy (viola tricolor) a factorial experiment based on completely randomized design with 3 replications and 18 treatments was conducted at the greenhouses of Ferdowsi University of Mashhad at 2009. The treatments are including; 2 concentrations of carbon dioxide (380 and 1000 µmol/mol), 3 light regimes (11000 and 14000 lux and sun light) and 3 cultivars (Yellow-Black, Bourdeaux, Sawyers-Black) of Pansy. The results of this experiment showed that among the 11 measured traits in the most treatments, the traits of length, width and the number of stomata and dry weight of shoot were significant. The concentration of 1000 µmol/mol carbon dioxide had less decreasing of stomata conductivity and dry weight than carbon dioxide 380 µmol/mol. Totally the effect of light regimes on the measured traits didn’t has any significantly difference with sun light. Among the cultivars, altogether Sawyers was more proper because of less stomata conductivity and probably decreasing of water consumption.
