Studies On Resistance Of Urban Garden Plants In Dongying City

Street landscaping and central urban landscaping were studied which were based on the practical case of landscaping in Dongying City during 2003～2004. Experiment was done in the main sections of city urban, the light intensity and light transmission rate were determined before and after canopy in street landscaping and central urban landscaping, the low light and salt tolerances of existing vegetations and introduce species were studied. Besides, the low light and salt tolerances were compared between different introduce species in order to screen some plant adapted to grown in landscaping of Dongying City. The main results as below:1. Whatever the light intensity or the light transmission rate before and after canopy in street landscaping and central urban landscaping were rather low. The difference of light transmission rate between sections of street landscaping was not significant as well as sections of central urban landscaping, but the difference was significant between street landscaping and central urban landscaping. The light intensity in street landscaping was different because of plant density, and the light intensity in central urban landscaping has no notable mosaic distribution because plants were grown large scale.2. The adaptability to low light intensity of different introduce species was different. These plants could be divided into tolerant shade plant, less tolerant shade plant and not tolerant shade plant according to photosynthesis rate and growth status under low light intensity. Ophiopogon Japonicus and euonymus fortunei (except golden leaf Euonymus fortunei) could grow well under low light intensity, but the growth of belamcanda chinensis and spiraea were bad and the new branches were thin.3. Leaf electric conductivity of Ophiopogon Japonicus had no significant change under low salt stress (electric conductivity was less than 1.5ms/cm) and electric conductivity would increase sharply with the increase of salt concentration. Leaf electric conductivity of golden leaf Hosta plantaginea increase quickly with the increase of soil electric conductivity. The salt tolerance of Ophiopogon Japonicus was better but of golden leaf Hosta plantaginea was middle.4. Wilting water contents of Ophiopogon Japonicus, Hosta plantaginea and belamcanda chinensis were 10.5%, 9.7% and 16.7%. Water tolerance of Hosta plantaginea was best but of belamcanda chinensis was least. Wilting water contents of Ophiopogon Japonicus, Hosta plantaginea and belamcanda chinensis were decreased sharply when the soil electric conductivity was 1.14 ms/cm, the reduction of Ophiopogon Japonicus was the least and of Hosta plantaginea was the most. Wilting water contents were different with the salt content of soil for the same plant, and the wilting water content was high while the salt content of soil was high.