Wheat samples were collected from Hetao Area, Inner Mongolia, and their poisonous, harmful and beneficial elements contents were analyzed. According to the standards for heavy metals in wheat green food, the Hg, Cd, A...Wheat samples were collected from Hetao Area, Inner Mongolia, and their poisonous, harmful and beneficial elements contents were analyzed. According to the standards for heavy metals in wheat green food, the Hg, Cd, As and Pb contents in the wheat samples collected from Qiantao Area were all below the national standards, indicating that they were green; and the heavy metals contents in the wheat samples collected from Houtao Area were basically in line with the pollutionfree food hygiene standards, indicating that they were not harmful to human body. Harmful elements Cd and Hg were more enriched in the wheat samples from Qiantao Area, but their contents were all lower than the national food standards, indicating that the wheat from Qiantao Area was not harmful to human health. The wheat from Houtao Area was rich in essential trace elements Cu, Zn, Se and K, and long-term consumption was beneficial to human health.展开更多
The analysis of environmental impact effects on forest ecosystems has a theoretical and practical nature. Many methods have been developed to determine characteristics and intensity of this impact. Methodologically, t...The analysis of environmental impact effects on forest ecosystems has a theoretical and practical nature. Many methods have been developed to determine characteristics and intensity of this impact. Methodologically, they can be divided into three groups： environmental parameter, bioindicative and combined methods. To evaluate the environmental impact a combined method was used in this study, it was based on trees as the bioindicators and their response reactions, and environmental parameter analysis. In this study the bioindicator was Norway spruce （Picea abies （L.） Karst.）, whose response reaction was used to explain total impact volumes of environmental factors in different places in the region of Kurzeme and try to interpret the causes of these differences. As the bioindicators criterion was used response reaction of Norway spruce during a period of 20 years, which was expressed with cumulative and annual additional volume increment, and was depending on the location of the stand and its morphometric characteristics. The empirical material was collected in Kurzeme region in 28 sample plots that are located on two transects and in one reference stand. For the evaluation the widths of the last 40 year growth rings were measured. To express the environmental impact in Kurzeme region a multiple regression model was developed, which explains the environmental impact in the volume of 68.2%, the rest part can be explained by the local conditions of each stand. It must be noted that methodology used in this study is very sensitive, thus, each of the nuances in the dynamics of volume＇s annual reduced additional increments has biological and ecological cause.展开更多
基金Supported by Land Resources Survey Research Project of China Geological Survey(200414200005)~~
文摘Wheat samples were collected from Hetao Area, Inner Mongolia, and their poisonous, harmful and beneficial elements contents were analyzed. According to the standards for heavy metals in wheat green food, the Hg, Cd, As and Pb contents in the wheat samples collected from Qiantao Area were all below the national standards, indicating that they were green; and the heavy metals contents in the wheat samples collected from Houtao Area were basically in line with the pollutionfree food hygiene standards, indicating that they were not harmful to human body. Harmful elements Cd and Hg were more enriched in the wheat samples from Qiantao Area, but their contents were all lower than the national food standards, indicating that the wheat from Qiantao Area was not harmful to human health. The wheat from Houtao Area was rich in essential trace elements Cu, Zn, Se and K, and long-term consumption was beneficial to human health.
文摘The analysis of environmental impact effects on forest ecosystems has a theoretical and practical nature. Many methods have been developed to determine characteristics and intensity of this impact. Methodologically, they can be divided into three groups： environmental parameter, bioindicative and combined methods. To evaluate the environmental impact a combined method was used in this study, it was based on trees as the bioindicators and their response reactions, and environmental parameter analysis. In this study the bioindicator was Norway spruce （Picea abies （L.） Karst.）, whose response reaction was used to explain total impact volumes of environmental factors in different places in the region of Kurzeme and try to interpret the causes of these differences. As the bioindicators criterion was used response reaction of Norway spruce during a period of 20 years, which was expressed with cumulative and annual additional volume increment, and was depending on the location of the stand and its morphometric characteristics. The empirical material was collected in Kurzeme region in 28 sample plots that are located on two transects and in one reference stand. For the evaluation the widths of the last 40 year growth rings were measured. To express the environmental impact in Kurzeme region a multiple regression model was developed, which explains the environmental impact in the volume of 68.2%, the rest part can be explained by the local conditions of each stand. It must be noted that methodology used in this study is very sensitive, thus, each of the nuances in the dynamics of volume＇s annual reduced additional increments has biological and ecological cause.
