Soil nutrient content and biodiversity were investigated on the iron tailing land to detect impacts of forestation on the nutrient content and biodiversity. The results showed that the iron tailing had much lower cont...Soil nutrient content and biodiversity were investigated on the iron tailing land to detect impacts of forestation on the nutrient content and biodiversity. The results showed that the iron tailing had much lower contents of organic materials and available N than ordinary soil, and the iron tailing with forestation of Hippophae rhamnoides or Amorpha fruticos had higher contents of the two nutrients than the iron tailing without forestation. The species diversity index (including Simpson index and Shannon-Weiner index) and species richness index of the iron tailing with forestation of Hippophae rhamnoides or Amorpha fruticos were higher than that of the iron tailing without forestation, and the two indexes reached to the level of the nearby natural shrub forest. It was concluded that forestation was able to improve the soil nutrient condition of iron tailing in favor of the settlement of other species invaders, and to increase the species diversity. It would be a feasible way for iron tailings management to introduce the suitable plant species into the droughty and arid iron tailing land to enrich it and raise species diversity gradually.展开更多
The water deficit in arid and semi-arid regions is the primary limiting factor for the development of urban greenery and forestation. In addition, planting the species that consume low levels of water is useful in ari...The water deficit in arid and semi-arid regions is the primary limiting factor for the development of urban greenery and forestation. In addition, planting the species that consume low levels of water is useful in arid and semi-arid regions that have poor water management measures. Leaf water potential(Ψ) is a physiological parameter that can be used to identify drought resistance in various species. Indeed, Ψ is one of the most important properties of a plant that can be measured using a pressure chamber. Drought avoiding or drought resistant species have a lower Ψ than plants that use normal or high levels of water. To determine drought resistance of species that are suitable for afforestation in arid urban regions, we evaluated twenty woody species in the Isfahan City, central Iran. The experimental design was random split-split plots with five replications. The species were planted outdoor in plastic pots and then subjected to treatments that consisted of two soil types and five drip irrigation regimes. To evaluate the resistance of each species to drought, we used the Ψ and the number of survived plants to obtain the drought resistance index(DRI). Then, cluster analysis, dendrogram, and similarity index were used to group the species using DRI. Result indicates that the evaluated species were classified into five groups:(1) high water consuming species(DRI>–60 MPa);(2) above normal water consuming species(–60 MPa≥DRI>–90 MPa);(3) normal water consuming species(–90 MPa≥DRI>–120 MPa);(4) semi-drought resistant species(–120 MPa≥DRI>–150 MPa);and(5) drought resistant species(DRI≤–150 MPa). According to the DRI, Salix babylonica L., Populus alba L., and P. nigra L. are high water consuming species, Platanus orientalis L. and Albizia julibrissin Benth are normal water consuming species, and Quercus infectoria Oliv. and Olea europaea L. can be considered as drought resistant species.展开更多
文摘Soil nutrient content and biodiversity were investigated on the iron tailing land to detect impacts of forestation on the nutrient content and biodiversity. The results showed that the iron tailing had much lower contents of organic materials and available N than ordinary soil, and the iron tailing with forestation of Hippophae rhamnoides or Amorpha fruticos had higher contents of the two nutrients than the iron tailing without forestation. The species diversity index (including Simpson index and Shannon-Weiner index) and species richness index of the iron tailing with forestation of Hippophae rhamnoides or Amorpha fruticos were higher than that of the iron tailing without forestation, and the two indexes reached to the level of the nearby natural shrub forest. It was concluded that forestation was able to improve the soil nutrient condition of iron tailing in favor of the settlement of other species invaders, and to increase the species diversity. It would be a feasible way for iron tailings management to introduce the suitable plant species into the droughty and arid iron tailing land to enrich it and raise species diversity gradually.
文摘The water deficit in arid and semi-arid regions is the primary limiting factor for the development of urban greenery and forestation. In addition, planting the species that consume low levels of water is useful in arid and semi-arid regions that have poor water management measures. Leaf water potential(Ψ) is a physiological parameter that can be used to identify drought resistance in various species. Indeed, Ψ is one of the most important properties of a plant that can be measured using a pressure chamber. Drought avoiding or drought resistant species have a lower Ψ than plants that use normal or high levels of water. To determine drought resistance of species that are suitable for afforestation in arid urban regions, we evaluated twenty woody species in the Isfahan City, central Iran. The experimental design was random split-split plots with five replications. The species were planted outdoor in plastic pots and then subjected to treatments that consisted of two soil types and five drip irrigation regimes. To evaluate the resistance of each species to drought, we used the Ψ and the number of survived plants to obtain the drought resistance index(DRI). Then, cluster analysis, dendrogram, and similarity index were used to group the species using DRI. Result indicates that the evaluated species were classified into five groups:(1) high water consuming species(DRI>–60 MPa);(2) above normal water consuming species(–60 MPa≥DRI>–90 MPa);(3) normal water consuming species(–90 MPa≥DRI>–120 MPa);(4) semi-drought resistant species(–120 MPa≥DRI>–150 MPa);and(5) drought resistant species(DRI≤–150 MPa). According to the DRI, Salix babylonica L., Populus alba L., and P. nigra L. are high water consuming species, Platanus orientalis L. and Albizia julibrissin Benth are normal water consuming species, and Quercus infectoria Oliv. and Olea europaea L. can be considered as drought resistant species.
