Amorpha fruticosa L. （Fabaceae）, known as indigo bush, false indigo bush, false indigo and desert false indigo, is deciduous shrub （1-6 m tall）. The woody weed species A. fruticosa has a high environmental adaptab...Amorpha fruticosa L. （Fabaceae）, known as indigo bush, false indigo bush, false indigo and desert false indigo, is deciduous shrub （1-6 m tall）. The woody weed species A. fruticosa has a high environmental adaptability and is present in different environmental conditions. In Vojvodina region （Northern Serbia）, it is mostly present near irrigation channels and river banks, especially in alluvial or marshy areas. Since A. fruticosa is continually spreading near river banks, the aim of research was to determine seed bank composition near the Danube River. in 2014, soil sampling was performed at localities with high population of A. fruticosa （3-4 plants at age over two years and 10-14 plants at age 1-2 years）. Soil samples were taken from two localities （Futog and Sangaj） with alluvial sandy soil and chernozem near the Danube River. Each sample was sieved through a system of copper sieves of various diameters. After the separation of seeds from samples, they were identified. Significant presence of A. fruticosa seeds （1,914 seeds/m2） was established in a layer of 0-10 cm. In the same soil layer, the significant presence of seeds of Stellaria media （L.） Vill. and Urtica dioica L. were also established. Seeds ofA. fruticosa were not found in soil layers 10-20 cm and 20-30 cm. The invasive weed species A. fruticosa produces a large number of seeds in two cycles. The majority of the seeds stay in the upper soil layer, being dispersed by water （hydrochory）.展开更多
The sustainable system of cities is complicated and nonlinear. Environmental factors have significant impact on the city＇s sustainable development. This paper elaborates an environmental index system to evaluate whet...The sustainable system of cities is complicated and nonlinear. Environmental factors have significant impact on the city＇s sustainable development. This paper elaborates an environmental index system to evaluate whether the environmental factors have a profound influence on the city＇s sustainable development, and uses artificial neural network to assess the degree of influence.展开更多
文摘Amorpha fruticosa L. （Fabaceae）, known as indigo bush, false indigo bush, false indigo and desert false indigo, is deciduous shrub （1-6 m tall）. The woody weed species A. fruticosa has a high environmental adaptability and is present in different environmental conditions. In Vojvodina region （Northern Serbia）, it is mostly present near irrigation channels and river banks, especially in alluvial or marshy areas. Since A. fruticosa is continually spreading near river banks, the aim of research was to determine seed bank composition near the Danube River. in 2014, soil sampling was performed at localities with high population of A. fruticosa （3-4 plants at age over two years and 10-14 plants at age 1-2 years）. Soil samples were taken from two localities （Futog and Sangaj） with alluvial sandy soil and chernozem near the Danube River. Each sample was sieved through a system of copper sieves of various diameters. After the separation of seeds from samples, they were identified. Significant presence of A. fruticosa seeds （1,914 seeds/m2） was established in a layer of 0-10 cm. In the same soil layer, the significant presence of seeds of Stellaria media （L.） Vill. and Urtica dioica L. were also established. Seeds ofA. fruticosa were not found in soil layers 10-20 cm and 20-30 cm. The invasive weed species A. fruticosa produces a large number of seeds in two cycles. The majority of the seeds stay in the upper soil layer, being dispersed by water （hydrochory）.
文摘The sustainable system of cities is complicated and nonlinear. Environmental factors have significant impact on the city＇s sustainable development. This paper elaborates an environmental index system to evaluate whether the environmental factors have a profound influence on the city＇s sustainable development, and uses artificial neural network to assess the degree of influence.
