The Changjiang(Yangtze)River estuary has been subject to a variety of anthropogenic pressures in recent decades.To assess the ecological health of the coastal benthic ecosystem adjacent to the estuary,three surveys we...The Changjiang(Yangtze)River estuary has been subject to a variety of anthropogenic pressures in recent decades.To assess the ecological health of the coastal benthic ecosystem adjacent to the estuary,three surveys were conducted in 2005,2009,and 2010.The AZTI's Marine Biotic Index(AMBI)and multivariate-AMBI(M-AMBI)were used to analyse the benthic ecological status of this coast.The AMBI indicate that the ecological status of the coast adjacent to the Changjiang River estuary was only slightly degraded in all 3 years.In contrast,the M-AMBI indicated that the ecological status was seriously degraded,a result that is most likely due to pollution and eutrophication induced by human activities.The assessment of the coast's ecological status by the AMBI was not in agreement with that of the M-AMBI at some stations because of lower biodiversity values at those sites.The analysis of the two indices integrated with abiotic parameters showed that the M-AMBI could be used as a suitable bio-indicator index to assess the benthic ecological status of the coast adjacent to the Changjiang River estuary.The reference conditions proposed for the coast of the Changjiang River estuary should be further evaluated in future studies.Designation of local species could also provide an important reference for Chinese waters.To improve the reliability of AMBI and M-AMBI,further research into the ecology of local species is required to understand their arrangement in ecological groups.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 the National Special Research Fund for Non-profit Sector(Environmental Protection)(No.2008467041)the National Natural Science Foundation of China(No.40976086)
文摘The Changjiang(Yangtze)River estuary has been subject to a variety of anthropogenic pressures in recent decades.To assess the ecological health of the coastal benthic ecosystem adjacent to the estuary,three surveys were conducted in 2005,2009,and 2010.The AZTI's Marine Biotic Index(AMBI)and multivariate-AMBI(M-AMBI)were used to analyse the benthic ecological status of this coast.The AMBI indicate that the ecological status of the coast adjacent to the Changjiang River estuary was only slightly degraded in all 3 years.In contrast,the M-AMBI indicated that the ecological status was seriously degraded,a result that is most likely due to pollution and eutrophication induced by human activities.The assessment of the coast's ecological status by the AMBI was not in agreement with that of the M-AMBI at some stations because of lower biodiversity values at those sites.The analysis of the two indices integrated with abiotic parameters showed that the M-AMBI could be used as a suitable bio-indicator index to assess the benthic ecological status of the coast adjacent to the Changjiang River estuary.The reference conditions proposed for the coast of the Changjiang River estuary should be further evaluated in future studies.Designation of local species could also provide an important reference for Chinese waters.To improve the reliability of AMBI and M-AMBI,further research into the ecology of local species is required to understand their arrangement in ecological groups.
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.
