Deicing chemicals are widely used to clear the pavement snow in the cold areas of China and many other countries in winter, because of their simple operation and excellent snow-melting effect, which leads to more convenience for traffic and low probability of traffic accident in the city, especially in metropolis. However, with the ever-growing application of deicing chemicals, their negative effects on environment such as soil and water system increased dramatically. Based on the related researches in China and abroad, this paper summarized the two categories of deicing chemicals and their working principles, and then provided the unique characteristics of deicing chemicals’ effects on soil and water environment in large cities, which may need considerable quantity of the chemicals to relieve traffic congestion. What's more, main aspects of impacts by deicing chemicals on regional soil and water environment and the fundamental factors related to the aspects above respectively were generalized, in order to propose a conceptual model to evaluate the harmful effects. Moreover, this paper put forward some suggestions for the further research in this field to fulfill the model, and provided a scientific basis for the pollution prevention of deicing chemicals on urban environment.

Evaluation on the Effects of Deicing Chemicals on Soil and Water Environment

Obligate aerobic AMF taxa have high species richness under waterlogged conditions, but their ecological role remains unclear. Here we focused on AM fungal mediation of plant interactions in a marshland plant community. Five cooccurring plant species were chosen for a neighbor removal experiment in which benomyl was used to suppress AMF colonization. A Phragmites australis removal experiment was also performed to study its role in promoting AMF colonization by increasing rhizosphere oxygen concentration. Mycorrhizal fungal effects on plant interactions were different for dominant and subdominant plant species. AMF colonization has driven positive neighbor effects for three subdominant plant species including Kummerowia striata, Leonurus artemisia, and Ixeris polycephala. In contrast, AMF colonization enhanced the negative effects of neighbors on the dominant Conyza canadensis and had no significant impact on the neighbor interaction to the dominant Polygonum pubescens. AM colonization was positively related to oxygen concentration. P. australis increased oxygen concentration, enhanced AMF colonization, and was thus indirectly capable of influencing plant interactions. Aerobic AM fungi appear to be ecologically relevant in this wetland ecosystem. They drive positive neighbor interactions for subdominant plant species, effectively increasing plant diversity. We suggest, therefore, that AM fungi may be ecologically important even under waterlogged conditions.

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Arbuscular Mycorrhizal Fungal Mediation of Plant-Plant Interactions in a Marshland Plant Community

Composition of photosynthetic pigments and photosynthetic characteristics in green and yellow sectors of the variegated Aucuba japonica ‘Variegata’ leaves

The Cropland Conversion Program (CCP) project in Loess Plateau is a main eco-environment construction project that aims at reducing the sediment yield of The Yellow River and improving local environment. However, the barren soil in this area caused the low productivity of the plant seedlings. Based on this phenomenon, this paper investigates the effects of applying nitrogen upon photosynthesis characters of the 2-year Q.liaotungensis seedlings by testing the photosynthesis indicators in controlled pots. Results show that: (1) applying nitrogen could place significant influence on Q.liaotungensis growth and photosynthesis product distribution, e.g. the most significant increase of the aboveground part biomass is 20.14% and 25.00% higher in leaf and stem than in control pot; (2) applying nitrogen increased both the net photosynthesis rate (Pn) and the maximum Pn, and broadened the growth light intensity of Q.liaotungensis seedlings. Among different concentrations of nitrogen, it was found that the Pn increase became most significant when applying nitrogen at the concentration of 0.10 g/kg. The average increase of the maximum Pn reached 21.8% at this concentration. (3) Reasonable fertilization might have influenced the concentration of leaf nitrogen content and the activity of nitrate reductase which affects abscisic acid (ABA) content and ultimately causes the variation of Tr and Pn of Q.liaotungensis seedlings. The result can be used to guide the soil amelioration process for planting forest in soil barren area, e.g. Loess Plateau, which can also be helpful in providing the theoretical basis for the reasonable and sustainable progress of the CCP project.

Effects of applying nitrogen upon photosynthesis characters in Quercus liaotungensis

记载了分布于山东省的两个湖北海棠的地理变种，泰山海棠与原变种区别于叶缘锯齿较钝较小，果实紫红色，直径约0．6cm，花较小，直径不足2cm；平邑甜茶与原变种区别于叶片较大，平展，锯齿大而钝，叶脉较多，较直行，花萼齿披针形，长于萼筒。

山东湖北海棠(Malus hupehensis (Pamp.) Rehd.)两新变种

Hefei city was suffered from a serious snowstorm in early 2008.During the snowstorm,agent for snow melting was widely used among five major transportation corridors.The study on the soil in these green belts areas that were covered by snow shows that: ①0～10 cm surface layer soil from Changjiang Road a neutral pH,other soil samples have pH values ranged from 7.47 to 8.92,which shows that the soil is alkaline;②The average pH value of the 0~10 cm surface layer soil from Fuyang Road and the 10~30 cm surface layer soil from Shouchun Road are close to the pH value of the control,however,the average pH value of the other soil samples is significantly higher than that of the control;③ The average EC value of the soil is from 21.9.% to 86.1%,higher than that of the control,with the exception of the average EC value of the 0~10 cm surface layer soil from Wuhu Road,the 10~30 cm surface layer soil from Mengcheng Road and the 10~30 cm surface layer soil from Wuhu Road,which are close to the EC value of the control;④For samples collected from all five roads,the water-soluble Na+ value in the 0~10 cm surface layer soil are from 8.5% to 161.9%,higher than that of the control;and all the 10~30 cm surface layer soil have Na+ values that are from 8.2% to 126.0%,higher than that of the control;⑤ T-tests analysis of the pH,EC and the Na+ value for each of the samples collected from the five roads show that the pH values from Changjiang Road,Mengcheng Road,Wuhu Road at 0~10 cm level and have significant difference with that from Changjiang Road,Wuhu Road at 10~30 cm level,although the difference of pH value between the other soil samples and the control is not remarkable,all samples collected from the five major roads do not have significant difference in the EC value and the soluble Na+ value with the control;⑥ The relevant analysis of the pH,EC and the Na+ values shows that there is no significant relationships between the pH value and the EC value,the pH and the Na+ value,or the EC and the Na+.The results show that snow-melting agent in Hefei city did not result in serious pollution to the green-belts soil.

Analysis of residue of agent for snow melting in soil during the snowstorm in early 2008 in Hefei.

The photosynthetic physiological characters of Aucuba japonica f.variegata,a common used ground cover plant in urban landscape,were studied in the paper.All data was collected using Li-6400 system in field in growing seasons.The results showed that the diurnal variation of net photosynthetic rate presented the double-peak curve type in spring,summer and autumn;the species had the low light compensation point of 29.71 μmol·m-2·s-1and the higher light saturation point of 700 μmol·m-2·s-1.Based on the analysis,the species could be identified as a neutral shrub with shade tolerance and intolerant to direct sunlight.The multiple regression analysis was used to describe the importance of the different factors on the net photosynthetic rate,the results indicated that stomatal conductance played the most important role on net photosynthetic rate in growing season.As well as,based on both correlation analysis and path coefficient analysis,the authors concluded that decreasing temperature appropriately and increasing relative humidity could enhance its light utilization efficiency.As a colorful landscape shrub,the species should be planted under canopy or on the north side of buildings to avoid direct sunlight.

Photosynthetic physiological characters of Aucuba japonica f. variegata.

In this paper,based on the data on poplar plantation undergrowth communities from three plots and some original nonforest river marshlands, the undergrowth community diversity of the river marshland oncomelania-control and schistosomasis-prevention forests in the middle and lower reaches of Yangtze River was analyzed from the perspectives of species richness, uniformity and species diversity index. The results showed that the botanical diversity increased after afforestation and varied in different-aged plantations with 3-year plantations having the highest botanical diversity index and 8-year plantations having the highest uniformity. River marshland afforestation enriched the botanical community diversity which would show a downtrend along with the stand canopy closure limiting the undergrowth. The results showed that the stand canopy density of the plantations dominated the undergrowth species composition and distribution.

Study on the Botanical Diversity in Marshland Poplar Plantations in the Middle and Lower Reaches of Yangtze River

The photosynthetic physiologic characteristics of Shibataea hispida were studied,the results indicated that S.hispida had a higher saturation point of 1 450 μmol·m~(-2)·s~(-1) and a quite lower light compensation point of approximate 14.4 μmol·m~(-2)·s~(-1),belonging to heliophytic bamboo species, but it also could tolerate shade, and being suitable to a multiple light condition.The main factors influencing net photosynthetic rates of S.hispida were stomatal conductance, and then the air relative humidity and transpiration rates in the summer.The results also indicated that a positive relationship existed between the utilization efficiency of light energy of the new leaves and air relative humidity,increasing environmental humidity could reasonably enhance the utilization efficiency of light energy in the summer. It was suitable to be planted under full sun light,side-shade or part-shade,and also be used to cover land of city gardens.

Photosynthetic Physiologic Characteristics of Shibataea hispida in Anhui Province

Geographic distribution of Malus hupehensis was modelled with MaxEnt by 551 presence recorded data and current bioclimatic data.The results showed that: ①Malus hupehensis would be more likely to occur in those areas(potential distribution),such as northern Pakistan,northern India,Nepal,Bhutan,northeast Myanmar,northwest of Vietnam,northern of Guangxi,the southern and southeastern of Xizang,southeast of Japan,south,center and coast of Korea,northeast of Hebei,north of Shandong,southern of Liaoning.Of which,the areas with 0.6-1 distribution value(logistic) are Bhutan,Cheju Island and coastal islands of Korea,Japan islands and the its nearby islands.② The areas with distribution values 0.6-1 were in the southeast of Shanxi,Nantong of Jiangsu,Hanyuan of Sichuan,and Laoshan of Shandong,although,there were a few present records in those areas.③ Geographical distribution patterns of M.hupehensis could be expressed using those areas with distribution value 0.6-1,from west to east,the southern and southeastern of the Himalayas,Hengduan Mountains,Qinling Mountains,and Wu Mountains,the mountainous regions of middle and lower reaches of Yangtze River,Wuyi Mountains,Korean Peninsula,the Japan islands.From north to south,the most northern boundary was in the south of the Taihang Mountains,and the southern boundary was in the southwest of the Wuyi Mountains.④ It was showed that the average temperature in the dry season was the greatest contribution to the distribution gain of M.hupehensis by Jackknife Test,and it was distributed naturally over those areas with average temperature of ﹣ 10℃-15℃ in the dry season.

Huang Cheng-lin

Papers

Analysis of residue of agent for snow melting in soil during the snowstorm in early 2008 in Hefei.

Photosynthetic physiological characters of Aucuba japonica f. variegata.

Study on the Botanical Diversity in Marshland Poplar Plantations in the Middle and Lower Reaches of Yangtze River

Photosynthetic Physiologic Characteristics of Shibataea hispida in Anhui Province

Modelling geographic distribution of Malus hupehensis with MaxEnt.