The largest reed field in the world, with an area of 1000 km<sup>2</sup> in 1953, is located in the Liaohe Delta, which lies in the five-point-in-a-line economic strategic zone of northeastern China. Howev...The largest reed field in the world, with an area of 1000 km<sup>2</sup> in 1953, is located in the Liaohe Delta, which lies in the five-point-in-a-line economic strategic zone of northeastern China. However, the area of reeds has declined dramatically in recent years to accommodate oil field infrastructure and societal developments. Although the direct and indirect services provided by such wetlands make valuable contributions to human welfare, wetlands are often given little weight in policy decisions, because ecosystem services are not fully “captured” in commercial markets or adequately quantified in terms comparable with the values of economic services and manufactured capital. In this study the value of 10 of 17 ecosystem services provided by the reed wetlands in the Liaohe Delta was estimated by using market pricing, shadow projects, and benefit transfer methods. The value of the 10 services provided by the 800 km<sup>2</sup> of reed wetland totaled approximately US $2.68 billion. Remarkably, aquaculture and the production of pulp from reeds accounted for only 19% of the total value of the reed wetland services. About 32% of the value of the ecosystem services was attributed to non-consumptive recreation, an easily perceived service that may act as a powerful incentive for sustainable management of this wetland ecosystem. The results of this study should help not only to guide management decisions with respect to this particular wetland but also to serve as an example of the approach to be taken with respect to valuation of similarly endangered wetlands throughout China.展开更多
How common reed （Phragmites australis Trin. ex Steud.） colonization correlates to soil heterogeneity and environmental determinants remains unclear in arid areas. We conducted a field investigation and soil sampling...How common reed （Phragmites australis Trin. ex Steud.） colonization correlates to soil heterogeneity and environmental determinants remains unclear in arid areas. We conducted a field investigation and soil sampling in 100 plots along Keriya River Basin to uncover the relationship between common reed and heterogeneous soils. Reed colonization variables and its soil properties were measured and recorded for the analysis of their relationship using Pearson correlation and redundancy analysis methods. The comparison results of common reed characteris- tics among 100 plots showed that common reeds performed strong tolerance and ecophysiological plasticity to edaphic stresses. Common reed colonization was tightly connected to soil heterogeneity according to the correla- tion analysis between its colonization characteristics and soil properties. Common reed colonization got feedbacks on soil properties as well, including the increase of soil organic matter and the alleviation of salt uplifting. The main limiting environmental determinant of common reed colonization was soil salt, followed by pH and soil water content.展开更多
Shortage of freshwater is becoming a growing problem in both dry and semi-dry regions of the world,hence the need to make use of other source of water for agricultural production.The study was conducted to examine the...Shortage of freshwater is becoming a growing problem in both dry and semi-dry regions of the world,hence the need to make use of other source of water for agricultural production.The study was conducted to examine the performance of common reed in a constructed wetland for greywater treatment in Akure,Nigeria.Raw greywater was collected from Jadesola Hostel,Federal University of Technology,Akure,and pretreated through a combination of gravel of diameters<32 mm,24 mm and 16 mm with fine sand of diameter 0.2 mm arranged accordingly.The filtered water was thereafter released to a plastic constructed wetland(CW)which also consisted of same combination of layers of gravel and sand with common reed planted on it for complete treatment.The raw and treated greywater were analyzed for Biochemical Oxygen Demand(BOD),Chemical Oxygen Demand(COD),Total Dissolved Solid(TDS),and heavy metals.It was discovered that CW planted with common reed was effective in the treatment of greywater with reduction in BOD by 91.4%,COD by 91.5%and TDS by 38.7%.CW had appreciable removal effect on heavy metals with reduction in:manganese(Mn)from 0.100 ppm to 0.012 ppm,iron(Fe)from 0.014 ppm to 0.002 ppm,lead(Pb)from 0.05 ppm to 0.001 ppm and zinc(Zn)from 0.154 ppm to 0.148 ppm.Therefore,the use of common reed in constructed wetland for greywater treatment is recommended for farmers involved in irrigation with greywater,especially during dry seasons,and most importantly under the rising global water scarcity due to climate change.展开更多
棘禾草螟绒茧蜂Apanteles chiloniponellae You et Wang是荻、芦主要蛀茎害虫棘禾草螟Chilo niponella幼虫期的寄生天敌,平均寄生率13.3％。此蜂在湖北一年发生5～6代,以幼虫在寄主老熟幼虫体内越冬。8月份室温下完成一代,平均历期为33....棘禾草螟绒茧蜂Apanteles chiloniponellae You et Wang是荻、芦主要蛀茎害虫棘禾草螟Chilo niponella幼虫期的寄生天敌,平均寄生率13.3％。此蜂在湖北一年发生5～6代,以幼虫在寄主老熟幼虫体内越冬。8月份室温下完成一代,平均历期为33.4天。成蜂多于8～10时和17～19时羽化,寿命平均为26天。卵产于寄主体壁下。寄生蜂茧的平均历期为4.75天。以棘禾草螟作寄主,每头寄主平均出蜂29头。茧的羽化率为66.3％。寄主被寄生后,始无明显症状,后期食量锐减甚至不取食,行动迟缓,体表发皱变黄。寄主除上述外,尚有芦螟Chilo luteellus和条螟Proceras venosata。此蜂在田间分布不均匀,不同苇田及同一苇田不同位置种群数量不同。展开更多
Reed is one of the most frequent and dominant species in wetlands all over the world, with common reed （Phragmites australis （Cav.） Trin. ex Steud.） as the most widely distributed species. In many wetlands, P. aus...Reed is one of the most frequent and dominant species in wetlands all over the world, with common reed （Phragmites australis （Cav.） Trin. ex Steud.） as the most widely distributed species. In many wetlands, P. australis plays a highly ambivalent role. On the one hand, in many wetlands it purifies wastewater, provides habitat for numerous species, and is a potentially valuable raw material, while on the other hand it is an invasive species which expands aggressively, prevents fishing, blocks ditches and waterways, and builds monospecies stands. This paper uses the eutrophic reed-swamp of Wuliangsuhai Lake in Inner Mongolia, northern China, as a case to present the multiple benefits of regular reed cutting. The reed area and aboveground biomass production are calculated based on field data. Combined with data about water and reed nutrient content, the impact of reed cutting on the lake nutrient budget （N and P） is investigated. Currently, at this lake around 100,000 tons of reed are harvested in winter annually, removing 16% and 8% of the total nitrogen and phosphorus influx, respectively. Harvesting all available winter reed could increase the nutrient removal rates to 48% and 24%, respectively. We also consider the effects of summer harvesting, in which reed biomass removal could overcompensate for the nutrient influx but could potentially reduce reed regrowth.展开更多
Aims: Two genetically distinct clones of Phragmites australis were used to investigate the immediate response induced by osmotic stress. The study aimed at elucidating if the response time, the inhibition rate and the...Aims: Two genetically distinct clones of Phragmites australis were used to investigate the immediate response induced by osmotic stress. The study aimed at elucidating if the response time, the inhibition rate and the recovery from salinity stress vary between these two genotypes. The experimental work was conducted at the laboratory of the Institute of Bioscience, Aarhus University, Denmark. Methods: The light-saturated photosynthetic rate (Pmax), stomata conductance (gs) and transpiration rate (E) were measured over different periods of salt exposure (15, 70 and 240 minutes) and at different salt concentrations (20 and 40 parts per thousand salinity). Important findings: The osmotic stress induced stomata closure and reduction of Pmax and E for both clones. The clone-specific responses as measured through physiological parameters were negatively correlated with exposure time and salt concentration. During the 4-hour exposure at 20 ppt, the two clones were inhibited at different rates. The salt-sensitive Land-type showed an immediate reduction of Pmax, gs and E. No recovery was observed after removing the salt solution. At the same salt concentration, the reduction of Pmax gs and E of the Greeny-type was lower and immediate recovery was observed when the root zone was rinsed. Both clones were irreversibly inhibited after 4 hours of exposure to 40 ppt. Recovery was primarily related to exposure time, as Pmax, gs and E rates of both clones recovered completely after fresh-water rinsing in the 15-minute experiment. The Greeny-type also recovered after the 70-minute exposure, but not the Land-type.展开更多
Salt tolerance of Phragmites australis populations was investigated in natural reed habitats in the estuary of the Chikugogawa River, southwestern Japan. P. australis populations were selected along the salinity gradi...Salt tolerance of Phragmites australis populations was investigated in natural reed habitats in the estuary of the Chikugogawa River, southwestern Japan. P. australis populations were selected along the salinity gradient in the estuary, including limnetic (salinity 0.05%), oligohaline (0.4%) and polyhaline sections (2.5%). The ratio of Total-P/Total-N of river water showed high values in the oligohaline section and the above ground biomass, population height and culm diameter of P. australis showed maximum values in this section. Sufficient phosphorus supply could sustain the high productivity of the community in the oligohaline section, irrespective of the salinity of inundated water. The seed production of P. australis was lowest in the polyhaline section. Thus, the ecological performance of P. australis was highest in the oligohaline section and the performance declined with the increasing salinity of the habitat. The effects of salinity on germination and seedling growth were evaluated by means of cultivation in 0.0% -5.0% (NaCl w/w%) salinity medium. Seeds of P. australis collected from every natural population in the estuary failed to germinate at salinity levels above 2.3%. Growth of shoot length and above-ground biomass of seedlings germinated in the fresh water medium were measured for 21 days’ exposure to constant salinity solutions ranging from 0.0% -5.0%. Although mortality was high at salinity levels 3.5% and 5.0%, elongation of shoots of some plants was evident at a salinity level of 5.0%. Seeds from the population in the limnetic section never germinated at a salinity of 3.5%, whereas seedlings obtained from the seeds of the same population germinated in freshwater conditions grew under a salinity of 3.5%. Thus, P. australis seedlings have higher salt tolerance compared to that during the germination stage of the seeds. In this study, it is clarified that P. australis has low salt tolerance during the germination stage and then it acquires salt tolerance during the stage of seedling growth.展开更多
Background: Resemblance to raptors such as hawks(Accipiter spp.) is considered to be an adaptive strategy of cuckoos(Cuculus spp.), which has evolved to protect cuckoos against host attacks. However, the effectiveness...Background: Resemblance to raptors such as hawks(Accipiter spp.) is considered to be an adaptive strategy of cuckoos(Cuculus spp.), which has evolved to protect cuckoos against host attacks. However, the effectiveness of the mimicry remains controversial, and is not yet fully studied for highly aggressive hosts.Methods: We evaluated the effectiveness of sparrowhawk(Accipiter nisus) mimicry by common cuckoos(Cuculus canorus) in oriental reed warblers(Acrocephaus orientalis), which are highly aggressive hosts. Using a both the single and the paired dummy experiment, defense behaviors and attack intensities of oriental reed warblers against common cuckoos, sparrowhawks and oriental turtle doves(Streptopelia orientalis) were assessed.Results: Oriental reed warblers exhibit strong nest defense behaviors, and such behaviors do not change with breeding stage(i.e., egg stage and nestling stage). Furthermore, assistance from conspecific helpers may increase attack intensities. However, they were deterred from mobbing overall by the presence of the hawk.Conclusions: Oriental reed warblers are able to distinguish cuckoos from harmless doves. However, they may be deterred from mobbing by the presence of the predatory hawk, suggesting hawk mimicry may be ineffective and does not reduce attacks of cuckoos by highly aggressive hosts.展开更多
文摘The largest reed field in the world, with an area of 1000 km<sup>2</sup> in 1953, is located in the Liaohe Delta, which lies in the five-point-in-a-line economic strategic zone of northeastern China. However, the area of reeds has declined dramatically in recent years to accommodate oil field infrastructure and societal developments. Although the direct and indirect services provided by such wetlands make valuable contributions to human welfare, wetlands are often given little weight in policy decisions, because ecosystem services are not fully “captured” in commercial markets or adequately quantified in terms comparable with the values of economic services and manufactured capital. In this study the value of 10 of 17 ecosystem services provided by the reed wetlands in the Liaohe Delta was estimated by using market pricing, shadow projects, and benefit transfer methods. The value of the 10 services provided by the 800 km<sup>2</sup> of reed wetland totaled approximately US $2.68 billion. Remarkably, aquaculture and the production of pulp from reeds accounted for only 19% of the total value of the reed wetland services. About 32% of the value of the ecosystem services was attributed to non-consumptive recreation, an easily perceived service that may act as a powerful incentive for sustainable management of this wetland ecosystem. The results of this study should help not only to guide management decisions with respect to this particular wetland but also to serve as an example of the approach to be taken with respect to valuation of similarly endangered wetlands throughout China.
基金supported by the Joint Funds of the National Natural Science Foundation of China (U1138303)
文摘How common reed （Phragmites australis Trin. ex Steud.） colonization correlates to soil heterogeneity and environmental determinants remains unclear in arid areas. We conducted a field investigation and soil sampling in 100 plots along Keriya River Basin to uncover the relationship between common reed and heterogeneous soils. Reed colonization variables and its soil properties were measured and recorded for the analysis of their relationship using Pearson correlation and redundancy analysis methods. The comparison results of common reed characteris- tics among 100 plots showed that common reeds performed strong tolerance and ecophysiological plasticity to edaphic stresses. Common reed colonization was tightly connected to soil heterogeneity according to the correla- tion analysis between its colonization characteristics and soil properties. Common reed colonization got feedbacks on soil properties as well, including the increase of soil organic matter and the alleviation of salt uplifting. The main limiting environmental determinant of common reed colonization was soil salt, followed by pH and soil water content.
文摘Shortage of freshwater is becoming a growing problem in both dry and semi-dry regions of the world,hence the need to make use of other source of water for agricultural production.The study was conducted to examine the performance of common reed in a constructed wetland for greywater treatment in Akure,Nigeria.Raw greywater was collected from Jadesola Hostel,Federal University of Technology,Akure,and pretreated through a combination of gravel of diameters<32 mm,24 mm and 16 mm with fine sand of diameter 0.2 mm arranged accordingly.The filtered water was thereafter released to a plastic constructed wetland(CW)which also consisted of same combination of layers of gravel and sand with common reed planted on it for complete treatment.The raw and treated greywater were analyzed for Biochemical Oxygen Demand(BOD),Chemical Oxygen Demand(COD),Total Dissolved Solid(TDS),and heavy metals.It was discovered that CW planted with common reed was effective in the treatment of greywater with reduction in BOD by 91.4%,COD by 91.5%and TDS by 38.7%.CW had appreciable removal effect on heavy metals with reduction in:manganese(Mn)from 0.100 ppm to 0.012 ppm,iron(Fe)from 0.014 ppm to 0.002 ppm,lead(Pb)from 0.05 ppm to 0.001 ppm and zinc(Zn)from 0.154 ppm to 0.148 ppm.Therefore,the use of common reed in constructed wetland for greywater treatment is recommended for farmers involved in irrigation with greywater,especially during dry seasons,and most importantly under the rising global water scarcity due to climate change.
文摘棘禾草螟绒茧蜂Apanteles chiloniponellae You et Wang是荻、芦主要蛀茎害虫棘禾草螟Chilo niponella幼虫期的寄生天敌,平均寄生率13.3％。此蜂在湖北一年发生5～6代,以幼虫在寄主老熟幼虫体内越冬。8月份室温下完成一代,平均历期为33.4天。成蜂多于8～10时和17～19时羽化,寿命平均为26天。卵产于寄主体壁下。寄生蜂茧的平均历期为4.75天。以棘禾草螟作寄主,每头寄主平均出蜂29头。茧的羽化率为66.3％。寄主被寄生后,始无明显症状,后期食量锐减甚至不取食,行动迟缓,体表发皱变黄。寄主除上述外,尚有芦螟Chilo luteellus和条螟Proceras venosata。此蜂在田间分布不均匀,不同苇田及同一苇田不同位置种群数量不同。
基金the financial support of the project "Sustainable Water Management and Wetland Restoration in Settlements of Continental-arid Central Asia" (Su Wa Rest) by the Kurt-Eberhard-Bode Foundation within the Stifterverband für die Deutsche Wissenschaft
文摘Reed is one of the most frequent and dominant species in wetlands all over the world, with common reed （Phragmites australis （Cav.） Trin. ex Steud.） as the most widely distributed species. In many wetlands, P. australis plays a highly ambivalent role. On the one hand, in many wetlands it purifies wastewater, provides habitat for numerous species, and is a potentially valuable raw material, while on the other hand it is an invasive species which expands aggressively, prevents fishing, blocks ditches and waterways, and builds monospecies stands. This paper uses the eutrophic reed-swamp of Wuliangsuhai Lake in Inner Mongolia, northern China, as a case to present the multiple benefits of regular reed cutting. The reed area and aboveground biomass production are calculated based on field data. Combined with data about water and reed nutrient content, the impact of reed cutting on the lake nutrient budget （N and P） is investigated. Currently, at this lake around 100,000 tons of reed are harvested in winter annually, removing 16% and 8% of the total nitrogen and phosphorus influx, respectively. Harvesting all available winter reed could increase the nutrient removal rates to 48% and 24%, respectively. We also consider the effects of summer harvesting, in which reed biomass removal could overcompensate for the nutrient influx but could potentially reduce reed regrowth.
文摘Aims: Two genetically distinct clones of Phragmites australis were used to investigate the immediate response induced by osmotic stress. The study aimed at elucidating if the response time, the inhibition rate and the recovery from salinity stress vary between these two genotypes. The experimental work was conducted at the laboratory of the Institute of Bioscience, Aarhus University, Denmark. Methods: The light-saturated photosynthetic rate (Pmax), stomata conductance (gs) and transpiration rate (E) were measured over different periods of salt exposure (15, 70 and 240 minutes) and at different salt concentrations (20 and 40 parts per thousand salinity). Important findings: The osmotic stress induced stomata closure and reduction of Pmax and E for both clones. The clone-specific responses as measured through physiological parameters were negatively correlated with exposure time and salt concentration. During the 4-hour exposure at 20 ppt, the two clones were inhibited at different rates. The salt-sensitive Land-type showed an immediate reduction of Pmax, gs and E. No recovery was observed after removing the salt solution. At the same salt concentration, the reduction of Pmax gs and E of the Greeny-type was lower and immediate recovery was observed when the root zone was rinsed. Both clones were irreversibly inhibited after 4 hours of exposure to 40 ppt. Recovery was primarily related to exposure time, as Pmax, gs and E rates of both clones recovered completely after fresh-water rinsing in the 15-minute experiment. The Greeny-type also recovered after the 70-minute exposure, but not the Land-type.
文摘Salt tolerance of Phragmites australis populations was investigated in natural reed habitats in the estuary of the Chikugogawa River, southwestern Japan. P. australis populations were selected along the salinity gradient in the estuary, including limnetic (salinity 0.05%), oligohaline (0.4%) and polyhaline sections (2.5%). The ratio of Total-P/Total-N of river water showed high values in the oligohaline section and the above ground biomass, population height and culm diameter of P. australis showed maximum values in this section. Sufficient phosphorus supply could sustain the high productivity of the community in the oligohaline section, irrespective of the salinity of inundated water. The seed production of P. australis was lowest in the polyhaline section. Thus, the ecological performance of P. australis was highest in the oligohaline section and the performance declined with the increasing salinity of the habitat. The effects of salinity on germination and seedling growth were evaluated by means of cultivation in 0.0% -5.0% (NaCl w/w%) salinity medium. Seeds of P. australis collected from every natural population in the estuary failed to germinate at salinity levels above 2.3%. Growth of shoot length and above-ground biomass of seedlings germinated in the fresh water medium were measured for 21 days’ exposure to constant salinity solutions ranging from 0.0% -5.0%. Although mortality was high at salinity levels 3.5% and 5.0%, elongation of shoots of some plants was evident at a salinity level of 5.0%. Seeds from the population in the limnetic section never germinated at a salinity of 3.5%, whereas seedlings obtained from the seeds of the same population germinated in freshwater conditions grew under a salinity of 3.5%. Thus, P. australis seedlings have higher salt tolerance compared to that during the germination stage of the seeds. In this study, it is clarified that P. australis has low salt tolerance during the germination stage and then it acquires salt tolerance during the stage of seedling growth.
基金supported by the National Natural Science Foundation of China(Nos.31672303 to CY,31472013 and 31772453 to WL)
文摘Background: Resemblance to raptors such as hawks(Accipiter spp.) is considered to be an adaptive strategy of cuckoos(Cuculus spp.), which has evolved to protect cuckoos against host attacks. However, the effectiveness of the mimicry remains controversial, and is not yet fully studied for highly aggressive hosts.Methods: We evaluated the effectiveness of sparrowhawk(Accipiter nisus) mimicry by common cuckoos(Cuculus canorus) in oriental reed warblers(Acrocephaus orientalis), which are highly aggressive hosts. Using a both the single and the paired dummy experiment, defense behaviors and attack intensities of oriental reed warblers against common cuckoos, sparrowhawks and oriental turtle doves(Streptopelia orientalis) were assessed.Results: Oriental reed warblers exhibit strong nest defense behaviors, and such behaviors do not change with breeding stage(i.e., egg stage and nestling stage). Furthermore, assistance from conspecific helpers may increase attack intensities. However, they were deterred from mobbing overall by the presence of the hawk.Conclusions: Oriental reed warblers are able to distinguish cuckoos from harmless doves. However, they may be deterred from mobbing by the presence of the predatory hawk, suggesting hawk mimicry may be ineffective and does not reduce attacks of cuckoos by highly aggressive hosts.
