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Frank Kansiime - One of the best experts on this subject based on the ideXlab platform.
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Response of Cyperus Papyrus productivity to changes in relative humidity, temperature and photosynthetically active radiation
African Journal of Plant Science, 2017Co-Authors: Alfonse Opio, B M Jones, Frank Kansiime, T. OtitiAbstract:Ecosystem development is related to climatic conditions. To assess the effect of seasonal changes in climate factors on Papyrus ecosystem development, community biomass was estimated non-destructively and climate factors recorded in the wetland. Absolute aerial biomass and productivity were not significantly different between wet and dry seasons. Although there was significant vapour pressure deficit change over the seasons, the impact on net primary productivity was not significant, but exhibited positive association during dry season. Primary productivity was positively related to photosynthetically active radiation during both dry and wet seasons. Except for the dry season that accounted for 26.1% of primary productivity, that of the wet season was independent (0%) of measured weather variables. Key words: Cyperus Papyrus, photosynthetically active radiation, productivity, relative humidity, temperature, wetlands.
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Growth and Development of Cyperus Papyrus in a Tropical Wetland
2016Co-Authors: Alfonse Opio, Frank Kansiime, Mike B. Jones, T. OtitiAbstract: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 establish-ment of relationship between culm diameter and dry weight. Measurements were made over pe-riod 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 senes-cence. 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 th
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The potential use of Papyrus (Cyperus Papyrus L.) wetlands as a source of biomass energy for sub-Saharan Africa
GCB Bioenergy, 2016Co-Authors: Michael B. Jones, Frank Kansiime, Matthew SaundersAbstract:Four of five people in sub-Saharan Africa rely on the traditional use of solid biomass, mainly fuelwood, for cooking. In some areas, the current rate of fuelwood consumption will exhaust biomass reserves within the next decade or two. A largely unrecognized source of biomass are tropical wetland ecosystems which have been shown to be some of the most productive ecosystems globally, exhibiting rates of net primary productivity comparable with high-input, intensively managed agricultural systems. Papyrus (Cyperus Papyrus L.) is an emergent sedge with C4 photosynthesis which is native to the wetlands, river valleys and lakes of central, eastern and southern Africa. The mean standing dry matter of culms and umbels measured at a number of locations throughout East Africa is 38.3 ± 21.6 tDM ha−1, and the aerial net primary productivity ranges between 25.9 and 136.4 tDM ha−1 yr−1. Papyrus vegetation can be harvested by hand and stacked on the rhizome mat for partial air-drying, and it has been demonstrated that an annual harvesting regime has no negative impacts on long-term productivity. The use of Papyrus as a biofuel for cooking and heating depends on converting it to a suitably combustible form, such as compressed or carbonized briquettes with a calorific value approximately one-third less than wood charcoal. While Papyrus has significant potential as a biofuel, we argue that an integrated management and decision-making framework for the sustainable utilization of Papyrus wetlands is required, in which all ecosystem services including the provision of biomass energy need to be assessed. Sustainability of Papyrus wetlands requires management which combines the strength of traditional communal governance and modern legislation to promote its utilization. In this way, local communities can benefit from the inherent advantages of tropical wetlands as very productive ecosystems.
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Dissolved organic carbon in a tropical wetland dominated by Cyperus Papyrus
Wetlands Ecology and Management, 2015Co-Authors: Alfonse Opio, Frank Kansiime, Mike B. Jones, T. OtitiAbstract:To improve understanding of carbon budgets in tropical wetlands, there is need to include estimates of fluxes of dissolved organic carbon (DOC) which are usually influenced by hydrological conditions. In this study, an assessment was made to test the hypotheses that tropical wetlands show significant fluvial losses of organic carbon and that these fluvial losses vary seasonally depending on the rate of water movement through the wetland. Measurements were made on a wetland dominated by Cyperus Papyrus near Kampala, Uganda. DOC loads were computed from inflows and outflows discharge during wet and dry season. The inflow and outflow DOC concentrations ranged between 5.99 and 7.48 mg l^−1 and 5.88–10.6 mg l^−1 during dry season, and 6.24–8.48 mg l^−1 and 6.20–23.65 mg l^−1 during wet season respectively. There was little difference (12.5 %) in the load coming in and going out in the wet season, so DOC loss was not detected at this time. In the dry season, the loads were much smaller but there was more going out than coming in (32.6 %), but nevertheless there was a detectable loss of carbon from the wetland at this time.
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Influence of climate variables on Cyperus Papyrus stomatal conductance in Lubigi wetland, Kampala, Uganda
African Journal of Aquatic Science, 2015Co-Authors: Alfonse Opio, Frank Kansiime, Michael B. Jones, T. OtitiAbstract:Cyperus Papyrus forms highly productive wetlands in tropical Africa, but the environmental control of transpirational water loss in wetlands is poorly understood. The influence of climate variables on Papyrus stomatal conductance in dry and wet seasons of the year was investigated in a wetland in Kampala, Uganda, in June–December, 2012. In situ measurements were made of local climate conditions in a Papyrus canopy and of bracteole stomatal conductance. Stomatal conductance was highest early in the day and declined as the day progressed, but stomata were more consistently open in the wet season than in the dry season. The daily cycle of stomatal conductance was influenced by temperature, incident radiation and vapour pressure deficit. Stomata were more sensitive to vapour pressure deficit changes during the wet season than in the dry season, closing sharply as vapour pressure deficit increased. This would seem to be a useful strategy for regulating transpiration, as it reduces water loss when the vapour pr...
Matthew Saunders - One of the best experts on this subject based on the ideXlab platform.
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The potential use of Papyrus (Cyperus Papyrus L.) wetlands as a source of biomass energy for sub-Saharan Africa
GCB Bioenergy, 2016Co-Authors: Michael B. Jones, Frank Kansiime, Matthew SaundersAbstract:Four of five people in sub-Saharan Africa rely on the traditional use of solid biomass, mainly fuelwood, for cooking. In some areas, the current rate of fuelwood consumption will exhaust biomass reserves within the next decade or two. A largely unrecognized source of biomass are tropical wetland ecosystems which have been shown to be some of the most productive ecosystems globally, exhibiting rates of net primary productivity comparable with high-input, intensively managed agricultural systems. Papyrus (Cyperus Papyrus L.) is an emergent sedge with C4 photosynthesis which is native to the wetlands, river valleys and lakes of central, eastern and southern Africa. The mean standing dry matter of culms and umbels measured at a number of locations throughout East Africa is 38.3 ± 21.6 tDM ha−1, and the aerial net primary productivity ranges between 25.9 and 136.4 tDM ha−1 yr−1. Papyrus vegetation can be harvested by hand and stacked on the rhizome mat for partial air-drying, and it has been demonstrated that an annual harvesting regime has no negative impacts on long-term productivity. The use of Papyrus as a biofuel for cooking and heating depends on converting it to a suitably combustible form, such as compressed or carbonized briquettes with a calorific value approximately one-third less than wood charcoal. While Papyrus has significant potential as a biofuel, we argue that an integrated management and decision-making framework for the sustainable utilization of Papyrus wetlands is required, in which all ecosystem services including the provision of biomass energy need to be assessed. Sustainability of Papyrus wetlands requires management which combines the strength of traditional communal governance and modern legislation to promote its utilization. In this way, local communities can benefit from the inherent advantages of tropical wetlands as very productive ecosystems.
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Fluxes of carbon and water in Cyperus Papyrus L. tropical wetlands
2006Co-Authors: Matthew SaundersAbstract:THESIS 7823%%%%Carbon dioxide (CO2 ), water vapour (H2O) and energy fluxes play important roles in the functioning of vegetative ecosystems and also influence the climate of our planet at both the regional and global scale through important feedback mechanisms. Tropical wetlands cover a very small proportion of the total continental land mass but because they are highly productive their contribution to global primary production far outweighs their limited distribution. Fluxes of CO2 , H2O and energy were measured using eddy covariance techniques from a stand of the C4 emergent sedge Cyperus Papyrus L. at the Kirinya West wetland, Jinja, Uganda and a formerly pristine Papyrus wetland, but now dominated by Colocasia antiquorum (cocoyam) cultivation at the Nakivubo wetland, Kampala, Uganda.
T. Otiti - One of the best experts on this subject based on the ideXlab platform.
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Response of Cyperus Papyrus productivity to changes in relative humidity, temperature and photosynthetically active radiation
African Journal of Plant Science, 2017Co-Authors: Alfonse Opio, B M Jones, Frank Kansiime, T. OtitiAbstract:Ecosystem development is related to climatic conditions. To assess the effect of seasonal changes in climate factors on Papyrus ecosystem development, community biomass was estimated non-destructively and climate factors recorded in the wetland. Absolute aerial biomass and productivity were not significantly different between wet and dry seasons. Although there was significant vapour pressure deficit change over the seasons, the impact on net primary productivity was not significant, but exhibited positive association during dry season. Primary productivity was positively related to photosynthetically active radiation during both dry and wet seasons. Except for the dry season that accounted for 26.1% of primary productivity, that of the wet season was independent (0%) of measured weather variables. Key words: Cyperus Papyrus, photosynthetically active radiation, productivity, relative humidity, temperature, wetlands.
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Growth and Development of Cyperus Papyrus in a Tropical Wetland
2016Co-Authors: Alfonse Opio, Frank Kansiime, Mike B. Jones, T. OtitiAbstract: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 establish-ment of relationship between culm diameter and dry weight. Measurements were made over pe-riod 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 senes-cence. 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 th
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Dissolved organic carbon in a tropical wetland dominated by Cyperus Papyrus
Wetlands Ecology and Management, 2015Co-Authors: Alfonse Opio, Frank Kansiime, Mike B. Jones, T. OtitiAbstract:To improve understanding of carbon budgets in tropical wetlands, there is need to include estimates of fluxes of dissolved organic carbon (DOC) which are usually influenced by hydrological conditions. In this study, an assessment was made to test the hypotheses that tropical wetlands show significant fluvial losses of organic carbon and that these fluvial losses vary seasonally depending on the rate of water movement through the wetland. Measurements were made on a wetland dominated by Cyperus Papyrus near Kampala, Uganda. DOC loads were computed from inflows and outflows discharge during wet and dry season. The inflow and outflow DOC concentrations ranged between 5.99 and 7.48 mg l^−1 and 5.88–10.6 mg l^−1 during dry season, and 6.24–8.48 mg l^−1 and 6.20–23.65 mg l^−1 during wet season respectively. There was little difference (12.5 %) in the load coming in and going out in the wet season, so DOC loss was not detected at this time. In the dry season, the loads were much smaller but there was more going out than coming in (32.6 %), but nevertheless there was a detectable loss of carbon from the wetland at this time.
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Influence of climate variables on Cyperus Papyrus stomatal conductance in Lubigi wetland, Kampala, Uganda
African Journal of Aquatic Science, 2015Co-Authors: Alfonse Opio, Frank Kansiime, Michael B. Jones, T. OtitiAbstract:Cyperus Papyrus forms highly productive wetlands in tropical Africa, but the environmental control of transpirational water loss in wetlands is poorly understood. The influence of climate variables on Papyrus stomatal conductance in dry and wet seasons of the year was investigated in a wetland in Kampala, Uganda, in June–December, 2012. In situ measurements were made of local climate conditions in a Papyrus canopy and of bracteole stomatal conductance. Stomatal conductance was highest early in the day and declined as the day progressed, but stomata were more consistently open in the wet season than in the dry season. The daily cycle of stomatal conductance was influenced by temperature, incident radiation and vapour pressure deficit. Stomata were more sensitive to vapour pressure deficit changes during the wet season than in the dry season, closing sharply as vapour pressure deficit increased. This would seem to be a useful strategy for regulating transpiration, as it reduces water loss when the vapour pr...
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Impact of Photosynthetically Active Radiation on Temperature, Relative Humidity, Wind Speed and Direction in Lubigi Cyperus Papyrus L. Wetland Surface
Advances in Research, 2015Co-Authors: Alfonse Opio, Frank Kansiime, T. OtitiAbstract:Photosynthetically active radiation (PAR) is dominant solar radiation reaching the earth surface. PAR changes in response to the position of the sun and length of the day can be complex and perhaps even counter – intuitive to ecosystems. Assessment of PAR on relative humidity (RH), temperature, wind speed and direction in Cyperus Papyrus (Papyrus) wetland canopy surface was done during the months of September, 2010 (wet month) and June, 2011 (dry month) when the sun is at the equator and Tropics of Cancer respectively. PAR picked up in the morning (7.00 hour) and exhibited similar pattern during the months, although September values were significantly higher between 07.00 - 08.00 hours, 12.00 - 15.00 hours and at 19.00 hour. Significant difference in PAR at 19.00 hour was associated with significant temperature change between 20.00 to 21.00 hours. Significant temperature change between the
Gunnel Dalhammar - One of the best experts on this subject based on the ideXlab platform.
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a comparative study of Cyperus Papyrus and miscanthidium violaceum based constructed wetlands for wastewater treatment in a tropical climate
Water Research, 2004Co-Authors: Joseph Kyambadde, Frank Kansiime, Lena Gumaelius, Gunnel DalhammarAbstract:Abstract The treatment efficiencies of constructed wetlands containing Cyperus Papyrus L. (Papyrus) and Miscanthidium violaceum (K. Schum.) Robyns (synonymous with Miscanthus violaceum (K. Schum) Pilg.) were investigated in a tropical climate (Kampala, Uganda). Papyrus showed higher ammonium-nitrogen and total reactive phosphorus (TRP) removal (75.3% and 83.2%) than Miscanthidium (61.5% and 48.4%) and unplanted controls (27.9% ammonium-nitrogen). No TRP removal was detected in control effluent. Nutrients (N and P) were significantly higher ( p Miscanthidium plant tissues. Plant uptake and storage was the major factor responsible for N and P removal in treatment line 2 (Papyrus) where it contributed 69.5% N and 88.8% P of the total N and P removed. It however accounted for only 15.8% N and 30.7% P of the total N and P removed by treatment line 3 ( Miscanthidium violaceum ). In addition, Papyrus exhibited a significantly larger ( p =0.000) number of adventitious roots than Miscanthidium . Nitrifying bacteria attached to Papyrus (2.15×10 6 ±1.53×10 5 MPN/g DW) and Miscanthidium roots (1.30×10 4 ±8.83×10 2 MPN/g DW) and the corresponding nitrification activities were consistent with this finding. Epiphytic nitrifiers appeared more important for total nitrification than those in peat or suspended in water. Papyrus root structures provided more microbial attachment sites, sufficient wastewater residence time, trapping and settlement of suspended particles, surface area for pollutant adsorption, uptake, assimilation in plant tissues and oxygen for organic and inorganic matter oxidation in the rhizosphere, accounting for its high treatment efficiency.
Michael B. Jones - One of the best experts on this subject based on the ideXlab platform.
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The potential use of Papyrus (Cyperus Papyrus L.) wetlands as a source of biomass energy for sub-Saharan Africa
GCB Bioenergy, 2016Co-Authors: Michael B. Jones, Frank Kansiime, Matthew SaundersAbstract:Four of five people in sub-Saharan Africa rely on the traditional use of solid biomass, mainly fuelwood, for cooking. In some areas, the current rate of fuelwood consumption will exhaust biomass reserves within the next decade or two. A largely unrecognized source of biomass are tropical wetland ecosystems which have been shown to be some of the most productive ecosystems globally, exhibiting rates of net primary productivity comparable with high-input, intensively managed agricultural systems. Papyrus (Cyperus Papyrus L.) is an emergent sedge with C4 photosynthesis which is native to the wetlands, river valleys and lakes of central, eastern and southern Africa. The mean standing dry matter of culms and umbels measured at a number of locations throughout East Africa is 38.3 ± 21.6 tDM ha−1, and the aerial net primary productivity ranges between 25.9 and 136.4 tDM ha−1 yr−1. Papyrus vegetation can be harvested by hand and stacked on the rhizome mat for partial air-drying, and it has been demonstrated that an annual harvesting regime has no negative impacts on long-term productivity. The use of Papyrus as a biofuel for cooking and heating depends on converting it to a suitably combustible form, such as compressed or carbonized briquettes with a calorific value approximately one-third less than wood charcoal. While Papyrus has significant potential as a biofuel, we argue that an integrated management and decision-making framework for the sustainable utilization of Papyrus wetlands is required, in which all ecosystem services including the provision of biomass energy need to be assessed. Sustainability of Papyrus wetlands requires management which combines the strength of traditional communal governance and modern legislation to promote its utilization. In this way, local communities can benefit from the inherent advantages of tropical wetlands as very productive ecosystems.
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Influence of climate variables on Cyperus Papyrus stomatal conductance in Lubigi wetland, Kampala, Uganda
African Journal of Aquatic Science, 2015Co-Authors: Alfonse Opio, Frank Kansiime, Michael B. Jones, T. OtitiAbstract:Cyperus Papyrus forms highly productive wetlands in tropical Africa, but the environmental control of transpirational water loss in wetlands is poorly understood. The influence of climate variables on Papyrus stomatal conductance in dry and wet seasons of the year was investigated in a wetland in Kampala, Uganda, in June–December, 2012. In situ measurements were made of local climate conditions in a Papyrus canopy and of bracteole stomatal conductance. Stomatal conductance was highest early in the day and declined as the day progressed, but stomata were more consistently open in the wet season than in the dry season. The daily cycle of stomatal conductance was influenced by temperature, incident radiation and vapour pressure deficit. Stomata were more sensitive to vapour pressure deficit changes during the wet season than in the dry season, closing sharply as vapour pressure deficit increased. This would seem to be a useful strategy for regulating transpiration, as it reduces water loss when the vapour pr...
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Growth and Development of Cyperus Papyrus in a Tropical Wetland
Open Journal of Ecology, 2014Co-Authors: Alfonse Opio, Frank Kansiime, Michael B. Jones, T. OtitiAbstract: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.
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CO2 and O2 transport in the aerenchyma of Cyperus Papyrus L.
Aquatic Botany, 1995Co-Authors: Michael B. JonesAbstract:Abstract Cyperus Papyrus L. (Papyrus) is an emergent wetland species with C 4 photosynthesis. Culms of Papyrus possess numerous large intercellular air cavities and functional ‘Kranz’ chlorenchyma which are involved in CO 2 recycling in the culm. In darkness, the CO 2 concentration in the culms increased to 74 times that of the ambient air. In the light, the culms greatly reduce the intercellular CO 2 concentrations by internal CO 2 recycling via photosynthesis. Results suggest that 35–57% of the CO 2 respired by the culm pith and rhizomes may be refixed by culm photosynthesis. The dynamics of O 2 transport in the intercellular spaces of the culms and the rhizomes were also studied. Both illumination and prolonged darkness had significant effects on the O 2 concentrations in the culm and rhizomes. While the water surrounding the rhizomes remained strongly hypoxic, the O 2 concentration in the submerged rhizomes was 15.1% during the day and 10.3% at night. The diffusive fluxes of CO 2 and O 2 within the Papyrus plant during the day and night were calculated. Results suggest that rapid CO 2 exchange occurs between the ambient air, internal atmosphere and the culm photosynthetic tissue. Also, there is a high O 2 flux, particularly at night, which is generated in the intercellular air spaces between the culm and the rhizome.
