Yala swamp wetland is the largest fresh water wetland ecosystem in Kenya supporting a broad biodiversity. It comprises of River Yala, the Yala swamp, Lakes Kanyaboli, Namboyo and Sare, and a portion of Lake Victoria n...Yala swamp wetland is the largest fresh water wetland ecosystem in Kenya supporting a broad biodiversity. It comprises of River Yala, the Yala swamp, Lakes Kanyaboli, Namboyo and Sare, and a portion of Lake Victoria neighboring the swamp. Approximately 2300 ha of land have been reclaimed and has been used for large-scale agriculture resulting in mass destruction of papyrus to create room for framing. Papyrus are known to be important in phytoremediation but despite this role information is limited, lacks supportive evidence and the empirical aspect on the levels of these pollutants in relation to the papyrus biomass is limited. The study is aimed at determining the effects of Cyperus papyrus on the water and sediment quality in Yala Swamp wetland. Six sampling sites were purposefully selected to monitor the variations of the physicochemical parameters (temperature, dissolved oxygen: DO, pH, biological oxygen demand: BOD, total suspended solids: TSS, turbidity, electrical conductivity: EC and total dissolved solids: TSS) and the levels selected nutrients (phosphorus and nitrates) in water and sediments as River Yala flows through Dominion Farms, Lake Sare which surrounded by Cyperus papyrus and finally into Lake Victoria. The samples were collected in triplicates during the wet and dry seasons (May and September 2015 respectively). The physicochemical parameters were measured in situ using a Hydrolab muiltimeter while the nutrients were analyzed using UV/Vis spectroscopy. Statistical analysis was done using SAS V9.0 software. The mean temperature was 26.19˚C ± 0.71˚C, DO: 3.72 ± 1.02 Mg/l, BOD: 3.9 ± 0.32 Mg/l, pH: 7.52 ± 0.17, TDS: 109 ± 86.33, EC: 173.26 ± 13.8 μS/cm, TSS: 12.42 ± 18.51 Mg/l and Turbidity: 12.29 ± 10.03 NTU. The values varied significantly at P 0.05 among all the sites. The results show that papyrus is useful in maintaining the required levels of physicochemical parameters. The study will assist in conservation of the papyrus to help phytoremediate pollutants from Dominion farms and the adjacent farms in order to have ecologically sound wetland.展开更多
Harvesting of papyrus biomass plays a significant role in regulating ecosystem services of which one of them is nutrient uptake and cycling. Despite Lake Victoria’s wetlands being important, little is understood abou...Harvesting of papyrus biomass plays a significant role in regulating ecosystem services of which one of them is nutrient uptake and cycling. Despite Lake Victoria’s wetlands being important, little is understood about its role in nutrient uptake and removal. Although there have been studies done in these wetlands, there is inadequate understanding on the implication of unselective biomass harvesting on the water quality of Lake Vitoria. At the same time, these wetlands are threatened by livelihood-related pressures which are driven by extreme hydrological regimes. This study focused on Nyando floodplain wetland located in the Eastern part of the shores of Lake Victoria which is a lifeline to many rural communities living around the lake. Papyrus biomass harvesting was assessed in two study sites of Nyando wetland and at different seasons in order to determine its implication on nutrient regulating services. Participatory tools, field survey, observation, field measurements and laboratory analysis were used. Harvesting of papyrus removed 530.6 Kg N/g DM/ha/day and 97 Kg P/g DM/ha/day in Ogenya while 771.2 Kg N/g DM/ha/day and 109.2 Kg P/g DM/ha/day were removed in Wasare. However, addition of nutrients to the wetland may lead to the problem of eutrophication especially at the site where interaction of wetland and lake water occurs. Understanding the role of papyrus harvesting patterns is crucial for better planning and management of this complex resource in a changing environment.展开更多
Relative growth rate (RGR) is an important parameter in plant growth models. However, no field measurements of RGR have been made in Cyperus papyrus (papyrus) wetlands. In this study, the growth dynamics of aerial sho...Relative growth rate (RGR) is an important parameter in plant growth models. However, no field measurements of RGR have been made in Cyperus papyrus (papyrus) wetlands. In this study, the growth dynamics of aerial shoots were investigated in a tropical papyrus wetland. The aim was to estimate temporal changes in the growth rates, and also establish the effect of water level and temperature change on total culm number, culm recruitment and senescence. Dry weights of shoots during their life cycle were determined using a non-destructive method after establishment of relationship between culm diameter and dry weight. Measurements were made over period of seven months. During the course of the measurements, culm density significantly increased from 16.1 to 35.9 culms.m-2. There were significant changes in both culm recruitment and senescence. Maximum RGR of developing culms was 1.04 g g-1 d-1. Using a culm density of 27 per m-2, productivity range was 16.74 to 37.37 g m-2 d-1. There was an inverse and significant relationship between rate of change in leaf weight ratio (LWR) and RGR of the culms. In conclusion, RGR of the aerial shoot development was controlled by rate of change in LWR from 41 to 156 days of growth. There was a strong and negative influence of water level fluctuation on total culm density.展开更多
Papyrus is increasingly suggested as an alternative bioenergy source to reduce the pressure on forest ecosystems. However, there are few studies on the economic viability of papyrus wetlands and the benefits for local...Papyrus is increasingly suggested as an alternative bioenergy source to reduce the pressure on forest ecosystems. However, there are few studies on the economic viability of papyrus wetlands and the benefits for local communities. We construct a village Computable General Equilibrium (CGE) model to examine whether papyrus harvesting and processing has the potential to improve local livelihoods and simultaneously counteract pressure on local forest resources. We apply the CGE model to a village in northern Zambia where overexploitation of forest resources to produce energy from firewood and charcoal poses a serious problem. The analysis is based on survey data?from 105 households collected in 2015. The model results show that papyrus briquetting would be a possible?alternative biofuel and that this technology improves household income and utility through?labor?reallocations. Higher opportunity costs lead to households switching from firewood extraction and charcoal production activities to papyrus harvesting and processing to produce bioenergy. Replacing energy supplies from firewood and charcoal with papyrus briquettes results in substitution effects between forest land and wetland and thereby reduces the pressure on local forest resources. The CGE approach allows for an economy-wide ex-ante analysis at village level and can support management decisions to ensure the success of papyrus bioenergy interventions.展开更多
The present investigation demonstrates the synergistic action of using a sedimentation unit together with Cyperus papyrus(L.)wetland enriched with zeolite mineral in one-year round experiment for treating wastewater.T...The present investigation demonstrates the synergistic action of using a sedimentation unit together with Cyperus papyrus(L.)wetland enriched with zeolite mineral in one-year round experiment for treating wastewater.The system was designed to support a horizontal surface flow pattern and showed satisfactory removal efficiencies for both physicochemical and bacteriological contaminants within 3 days of residence time.The removal efficiencies ranged between 76.3%and 98.8%for total suspended solids,turbidity,iron,biological oxygen demand,and ammonia.The bacterial indicators(total and fecal coliforms,as well as fecal streptococci)and the potential pathogens(Escherichia coli,Staphylococcus aureus,and Pseudomonas aeruginosa)showed removal efficiencies ranged between 96.9%and 99.8%.We expect the system to offer a smart management for every component according to zero waste principle.The treated effluent was reused to irrigate the landscape of pilot area,and the excess sludge was recycled as fertilizer and soil conditioner.The zeolite mineral did not require regeneration for almost 36 weeks of operation,and enhanced the density of shoots(14.11%)and the height of shoots(15.88%).The harvested plant biomass could be a profitable resource for potent antibacterial and antioxidant bioactive compounds.This could certainly offset part of the operation and maintenance costs and optimize the system implementation feasibility.Although the experiment was designed under local conditions,its results could provide insights to upgrade and optimize the performance of other analogous large-scale constructed wetlands.展开更多
文摘Yala swamp wetland is the largest fresh water wetland ecosystem in Kenya supporting a broad biodiversity. It comprises of River Yala, the Yala swamp, Lakes Kanyaboli, Namboyo and Sare, and a portion of Lake Victoria neighboring the swamp. Approximately 2300 ha of land have been reclaimed and has been used for large-scale agriculture resulting in mass destruction of papyrus to create room for framing. Papyrus are known to be important in phytoremediation but despite this role information is limited, lacks supportive evidence and the empirical aspect on the levels of these pollutants in relation to the papyrus biomass is limited. The study is aimed at determining the effects of Cyperus papyrus on the water and sediment quality in Yala Swamp wetland. Six sampling sites were purposefully selected to monitor the variations of the physicochemical parameters (temperature, dissolved oxygen: DO, pH, biological oxygen demand: BOD, total suspended solids: TSS, turbidity, electrical conductivity: EC and total dissolved solids: TSS) and the levels selected nutrients (phosphorus and nitrates) in water and sediments as River Yala flows through Dominion Farms, Lake Sare which surrounded by Cyperus papyrus and finally into Lake Victoria. The samples were collected in triplicates during the wet and dry seasons (May and September 2015 respectively). The physicochemical parameters were measured in situ using a Hydrolab muiltimeter while the nutrients were analyzed using UV/Vis spectroscopy. Statistical analysis was done using SAS V9.0 software. The mean temperature was 26.19˚C ± 0.71˚C, DO: 3.72 ± 1.02 Mg/l, BOD: 3.9 ± 0.32 Mg/l, pH: 7.52 ± 0.17, TDS: 109 ± 86.33, EC: 173.26 ± 13.8 μS/cm, TSS: 12.42 ± 18.51 Mg/l and Turbidity: 12.29 ± 10.03 NTU. The values varied significantly at P 0.05 among all the sites. The results show that papyrus is useful in maintaining the required levels of physicochemical parameters. The study will assist in conservation of the papyrus to help phytoremediate pollutants from Dominion farms and the adjacent farms in order to have ecologically sound wetland.
文摘Harvesting of papyrus biomass plays a significant role in regulating ecosystem services of which one of them is nutrient uptake and cycling. Despite Lake Victoria’s wetlands being important, little is understood about its role in nutrient uptake and removal. Although there have been studies done in these wetlands, there is inadequate understanding on the implication of unselective biomass harvesting on the water quality of Lake Vitoria. At the same time, these wetlands are threatened by livelihood-related pressures which are driven by extreme hydrological regimes. This study focused on Nyando floodplain wetland located in the Eastern part of the shores of Lake Victoria which is a lifeline to many rural communities living around the lake. Papyrus biomass harvesting was assessed in two study sites of Nyando wetland and at different seasons in order to determine its implication on nutrient regulating services. Participatory tools, field survey, observation, field measurements and laboratory analysis were used. Harvesting of papyrus removed 530.6 Kg N/g DM/ha/day and 97 Kg P/g DM/ha/day in Ogenya while 771.2 Kg N/g DM/ha/day and 109.2 Kg P/g DM/ha/day were removed in Wasare. However, addition of nutrients to the wetland may lead to the problem of eutrophication especially at the site where interaction of wetland and lake water occurs. Understanding the role of papyrus harvesting patterns is crucial for better planning and management of this complex resource in a changing environment.
文摘Relative growth rate (RGR) is an important parameter in plant growth models. However, no field measurements of RGR have been made in Cyperus papyrus (papyrus) wetlands. In this study, the growth dynamics of aerial shoots were investigated in a tropical papyrus wetland. The aim was to estimate temporal changes in the growth rates, and also establish the effect of water level and temperature change on total culm number, culm recruitment and senescence. Dry weights of shoots during their life cycle were determined using a non-destructive method after establishment of relationship between culm diameter and dry weight. Measurements were made over period of seven months. During the course of the measurements, culm density significantly increased from 16.1 to 35.9 culms.m-2. There were significant changes in both culm recruitment and senescence. Maximum RGR of developing culms was 1.04 g g-1 d-1. Using a culm density of 27 per m-2, productivity range was 16.74 to 37.37 g m-2 d-1. There was an inverse and significant relationship between rate of change in leaf weight ratio (LWR) and RGR of the culms. In conclusion, RGR of the aerial shoot development was controlled by rate of change in LWR from 41 to 156 days of growth. There was a strong and negative influence of water level fluctuation on total culm density.
文摘Papyrus is increasingly suggested as an alternative bioenergy source to reduce the pressure on forest ecosystems. However, there are few studies on the economic viability of papyrus wetlands and the benefits for local communities. We construct a village Computable General Equilibrium (CGE) model to examine whether papyrus harvesting and processing has the potential to improve local livelihoods and simultaneously counteract pressure on local forest resources. We apply the CGE model to a village in northern Zambia where overexploitation of forest resources to produce energy from firewood and charcoal poses a serious problem. The analysis is based on survey data?from 105 households collected in 2015. The model results show that papyrus briquetting would be a possible?alternative biofuel and that this technology improves household income and utility through?labor?reallocations. Higher opportunity costs lead to households switching from firewood extraction and charcoal production activities to papyrus harvesting and processing to produce bioenergy. Replacing energy supplies from firewood and charcoal with papyrus briquettes results in substitution effects between forest land and wetland and thereby reduces the pressure on local forest resources. The CGE approach allows for an economy-wide ex-ante analysis at village level and can support management decisions to ensure the success of papyrus bioenergy interventions.
基金The authors wish to express their gratitude to the Microbiology Dep.,Central Laboratory for Environmental Quality Monitoring(CLEQM),National Water Research Center(NWRC)in Egypt for supporting this work.The authors would like also to thank Mr.Kyle Bowman,Head Bioelectrochemical Engineer at Wase-tech,London,UK for his language editing revision of the manuscript.
文摘The present investigation demonstrates the synergistic action of using a sedimentation unit together with Cyperus papyrus(L.)wetland enriched with zeolite mineral in one-year round experiment for treating wastewater.The system was designed to support a horizontal surface flow pattern and showed satisfactory removal efficiencies for both physicochemical and bacteriological contaminants within 3 days of residence time.The removal efficiencies ranged between 76.3%and 98.8%for total suspended solids,turbidity,iron,biological oxygen demand,and ammonia.The bacterial indicators(total and fecal coliforms,as well as fecal streptococci)and the potential pathogens(Escherichia coli,Staphylococcus aureus,and Pseudomonas aeruginosa)showed removal efficiencies ranged between 96.9%and 99.8%.We expect the system to offer a smart management for every component according to zero waste principle.The treated effluent was reused to irrigate the landscape of pilot area,and the excess sludge was recycled as fertilizer and soil conditioner.The zeolite mineral did not require regeneration for almost 36 weeks of operation,and enhanced the density of shoots(14.11%)and the height of shoots(15.88%).The harvested plant biomass could be a profitable resource for potent antibacterial and antioxidant bioactive compounds.This could certainly offset part of the operation and maintenance costs and optimize the system implementation feasibility.Although the experiment was designed under local conditions,its results could provide insights to upgrade and optimize the performance of other analogous large-scale constructed wetlands.
