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An ecological survey of the termites (Isoptera) of Lochinvar National Park, Zambia
(Journal of the Entomological Society of Southern Africa, 1986) Nkunika, Phillip Obed Yobe
As a follow up to investigations already carried out for certain vertebrates, this article presents the first record of the Isoptera of Lochinvar National Park. 23 species have been collected there from three different ecosystems, including periodically flooded plains. Characteristics of habitat, nests and feeding behav¬iour of the termites and their place in the ecological niche is briefly discussed. Quantitative ecological research on the termite fauna of this National Park remains to be done.
Problems of sedimentation in small dams in Zambia
(Human Impact on Erosion and Sedimentation, 1997) Sichingabula, Henry
An inventory of small dams in Zambia and the results of a preliminary analysis of sediment loads for rivers and reservoirs are reported. A regression approach was used to determine relationships between drainage area and sediment load for 21 rivers based on available sediment concentration and discharge data. The resulting regression equation was applied to the drainage areas of 66 small dams located in Southern Province and rates of sediment input to the reservoirs were computed. By assuming 95% trap efficiency for sediment by the dams, the expected useful life of the reservoirs was also calculated. Calculated annual rates of sedimentation in small dams were found to range from 2 to 183 m3 year1 with a mean of 24.6 m3 year1. The estimates of reservoir useful life ranged from 200 tp 5100 years with a mean of 7314 years. Anthropogenic factors contributing to sediment generation and sedimentation in. reservoirs, community participation in dam construction and rehabilitation efforts together with conservation measures embarked on in the country are discussed. Qualitatively, it is concluded that sedimentation in the dams of Southern Province is serious. This calls for detailed quantitative research to assess the problem and to find ways of minimizing adverse impacts of soil erosion on environment and society.
Termite Identification,Damage and Control options in Southern Province, Zambia
(Republic of Zambia,Ministry of Agriculture,Food and Fisheries., 1998) Nkunika, Phillip Obed Yobe
This is a pilot diagnostic survey carried out in Choma,Kalomo district,Southern province to identify the major termite pests attacking plantations ,fruit trees and crops.
Termite Identification,Damage and Control options in Southern Province, Zambia
(Republic of Zambia,Ministry of Agriculture,Food and Fisheries., 1998) Nkunika, Phillip Obed Yobe
This is a pilot survey carried out in southern province Zambia Kalomo District to identify the major termite pests attacking plantations,fruit trees and crops
Rainfall variability, drought and implications of its impacts on Zambia, 1886-1996
(1998) Sichingabula, Henry
The theory of runs was used in the investigation of frequency of occurrence, duration, magnitude and severity of drought in 46 districts of Zambia, 1886-1996. The 30-year "normal" rainfall was used as the threshold for drought occurrence with most analyses restricted to the 1921-1970 period. Analysis revealed that rainfall variability, indicated by increasing 11-year coefficients of variation (CVs) for selected stations and decreasing rainfall trends observed in southern Zambia after 1975, was not extraordinary as similar conditions were experienced before the turn of 19th century. What was new, however, is that the decreasing rainfall after 1975 seems to be related to the accelerated global warming associated withanthropogenic activities. Implications of impacts of drought were assessed from scenarios of drought occurrence under the threat of rising global warming. Various drought adaptation measures are discussed. It is concluded that, in Zambia drought is a chronic phenomenon which requires pre-planned measures for minimizing its impacts.
Special study on sediment discharge and Its consequences (SedSS)
(United Nations Development Programme/Global Environment Facility (UNDP/GEF), 1999) Sichingabula, Henry
Lake Tanganyika is among Zambia's important fisheries which require protection from adverse impacts. Sedimentation is one of the threats to Lake Tanganyika's biodiversity. This is because deposition of sediment clogs streams and reduces their capacities. Pollution by sediment is also one of the major factors causing deterioration in quality of streams and lakes. The sediment deposited into streams, lakes and reservoirs destroys the habitat for fish and other species. In aquatic environments, sediment impairs the dissolved oxygen balance and obscures the light needed for aquatic growth, both of which are detrimental to aquatic life forms. Additionally, heavier sediment particles blanket fish spawning areas and cover food supplies for many species. Pesticides and nutrients origination from agricultural lands are carried off the land by sediment in surface runoff and add to the pollution of downstream waters. For example, phosphates are adsorbed by soil colloids and move into streams and lakes through erosion of soil particles on which it is adsorbed. Nitrogen fertilisers together with phosphorus are the major cause of eutrophication in lakes and rivers which is detrimental to aquatic species. Therefore, the prevention of soil erosion by good conservation practices are the most efficient means of controlling pollution from agricultural lands. The physical characteristics of Lake Tanganyika basin are to a large extent controlled by the geology which is dominated by meta-quartzites of Precambrian ages. These rocks with the high rainfall regime experienced in the area have given rise to the high leached sandveldt soils which characterise the plateau area. These features of the physical environment in the lake Tanganyika basin are discussed in detail. This report documents the activities of the Zambia Special Sediment Study undertaken in almost a period of one year. Methods of data collection an errors inherent in methods used are also discussed. The determination of volumes of discharge and sediment deposited in the lake employed on various statistical models in the development of rating curves. The models selected were tested for accuracy before they were applied to monitored water level data. The study found that mean flow discharges on rivers draining into Lake Tanganyika ranged from 1.426 m3 s-1 on Izi River to 98.563 m3 s-1 on Lufubu River. The lowest and maximum discharges ranged from 0.183 m3 s-1 on Lucheche River to 346.68 m3 s-1 per day on Lufubu River. Similarly, quantities of clastic suspended sediment deposited by the five rivers into the lake between September, 1998 and May, 1999 were found to range from 0.082 tonnes on Kalambo River to 1,539.634 tonnes per day on Lufubu River. The mean values of sediment deposited into Lake Tanganyika were found to range from 1.248 tonnes on Izi River to 208.603 tonnes per day on Lufubu River. Magnitude frequency analysis was used in the determination of the flow ranges which transport the most load in a single year. The effective discharge on the studied rivers was variable ranging from 0.78 m3 s-1 on Izi River to 258 m3 s-1 on the Lufubu River. The durations of these class-based effective discharges were found to range from 2.1% corresponding to the highest discharge, to 54.5% of the time on Izi River where the lowest event transported the most load. The sediment-discharge regimes for rivers in southern Lake Tanganyika basin were characterised by a uniform histogram having a well defined mode and a relatively frequent effective discharge. This was exemplified by Lucheche River. In cases where the regime in which the lower level flows were the effective discharge this was exemplified by Lunzua River
Occurence , severity and magnitude of hydrological drought in Zambia :impacts and implications
(1999) Sichingabula, Henry
Persistent occurrence of drought under increasing water supply demands for municipalities and agriculture, and under increased threat of global warming, requires increased understanding of drought characteristics and sustainable use of water resources. Using the theory of runs, several hydroiogical drought parameters of frequency of occurrence, run length, magnitude and run intensity, were investigated for the Kafue and Zambezi rivers. Objectives were to (a) determine magnitude-frequency characteristics of hydroiogical droughts; (b) determine some drought run parameters and frequency of their occurrence; and (c) propose a new approach for increasing Zambia's utilization of its water resources without jeopardizing international relations with neighbouring countries. Better understanding of droughts and assessment of Zambia's present and future water requirements will enable planners and decision makers to bring increased economic benefits to citizens. Zambia's drought and water scarcity problems are outlined and linked to some proposed regional water projects designed to divert water from the Zambezi River system. One possible solution to problems of drought and dwindling water levels on Kafue River is proposed.
Suspended sediment transport characteristics of upper Kaleya river,Southern Zambia
(2000) Sichingabula, Henry Walling, D.E. Collins, A.L. Leeks, Graham G.L.
Soil erosion has many negative impacts on agriculture and other land related activities and so there is an urgent need to find ways of controlling it. In a bid to increase the understanding of soil erosion and sediment transport processes in Zambia, a project, which was funded by the UK Department for International Development, was conducted in the Upper Kaleya River catchment, southern Zambia, between 1997 and 2000. Being primarily concerned with sediment budgeting, this project necessarily involved the collection of discharge and suspended sediment load data for estimating sediment yields from the study river. This paper reports the suspended sediment transport characteristics of Upper Kaleya River during the study period. Analysis of the data collected at the study catchment outlet, at Roadbridge, revealed that discharge ranged from zero, during some dry season months, to 3.65 m3 s-1, with a daily mean discharge of 0.406 m3 s-1. The corresponding suspended sediment loads ranged from zero to 253.9 tonnes, with a mean of 3.15 tonnes per day. Magnitude-frequency analysis revealed that the flow responsible for transporting most of the suspended sediment load was 1.44 m3 s-1. This discharge represented 1.5 % of the time. During the study period, the total cumulative discharge was estimated at 34.8 million m3, whilst the total suspended sediment load was estimated at 3,130 tonnes. It is concluded that, though the Upper Kaleya River catchment is small, measured discharge and suspended sediment fluxes are reasonably high. Ways of controlling soil loss and of improving water resource protection should therefore be encouraged among the local farmers. There is also an urgent need to conduct this type of research in larger catchments in Zambia and in southern Africa region in order that national and regional sediment-related control measures can be designed and implemented. KEY WORDS: Catchment, effective discharge, magnitude-frequency analysis, river discharge, soil erosion, suspended sediment load.
Using unsupported lead-210 measurements to investigate soil erosion and sediment delivery in a small Zambian catchment
(Elsevier, 2002) Sichingabula, Henry; Walling, D.E.; Collins, A.L.
Traditional techniques used to assemble information on rates of erosion and soil redistribution possess many important limitations. As a result, the use of environmental radionuclides, and more particularly 137Cs measurements, has attracted increasing attention in recent years as a means of obtaining spatially distributed information on rates of erosion and deposition. The application of the 137Cs approach is, however, hampered in some areas of the world where 137Cs inventories are low and the low concentrations of 137Cs found in soils and sediments cause problems for laboratory analysis. These problems will increase as time progresses due to the radioactive decay of the existing inventory, most of which was deposited as fallout ca. 40 years ago. This contribution explores the potential for using another fallout radionuclide, namely unsupported 210Pb, as an alternative to 137Cs, in the small (63 km2) Upper Kaleya catchment in southern Zambia where 137Cs inventories are already very low. The approach employed with unsupported 210Pb is similar to that used for 137Cs, although the essentially constant fallout of unsupported 210Pb through time means that the resulting estimates of erosion and soil redistribution rates reflect a longer period of time (ca. 100 years rather than ca. 40 years). The estimates of erosion and deposition rates derived from the unsupported 210Pb measurements are used to construct typical sediment budgets for the three main land-use types in the Upper Kaleya catchment, namely, commercial cultivation, communal cultivation and bush grazing. The results obtained from the unsupported 210Pb are compared with equivalent results based on 137Cs measurements provided by a previous investigation undertaken in the study catchment. The two sets of results are highly consistent. The study reported confirms the viability of using unsupported 210Pb as an alternative to 137Cs in this environment and demonstrates that conjunctive use of both radionuclides can provide additional information on the erosional history of a study area.
Documenting catchment suspended sediment sources: problems, approaches and prospects
(Progress in Physical Geography, 2004) Walling, Des,E.
Establishing catchment suspended sediment sources is fraught with difficulty. Data collection comprises indirect and direct approaches and an overview is provided. The indirect approach uses a range of techniques to measure or evaluate sediment mobilization. Yet, although recent technological advances in surveying, remote sensing and photogrammetry provide improved resolution of temporal and spatial patterns of catchment erosion, these procedures take no account of source–river connectivity and the uncertainties associated with sediment routing. It is therefore only possible to infer the provenance of suspended sediment loads on the exclusive basis of on-site erosion data for different portions of the upstream catchment unless supportive information on sediment delivery is readily available. In contrast, the direct approach attempts to link sediment sources and flux using alternative means and therefore avoids the need for complementary information. Sediment fingerprinting best represents the direct approach to sediment sourcing and there remains substantial scope for exploiting the potential of this technique. The spatial complexity of sediment mobilization and transfer at the catchment scale necessitates a distributed approach to modelling. Recent developments in computer power and programming techniques are proving useful in this respect, but assembling the input and validation data required by distributed models continues to pose problems and it is frequently difficult to apportion the relative contributions from individual sediment sources. General prospects for future developments are discussed. Key words: catchment suspended sediment sources, direct approach, indirect approach, modelling, sediment fingerprinting.
The catchment sediment budget as a management tool
(Environmental science & p o li c y, 2008) Walling, Des, E.
There is increasing recognition that fine sediment represents an important diffuse source pollutant in surface waters, due to its role in governing the transfer and fate of many substances, including nutrients, heavy metals, pesticides and other organic contaminants, and because of its impacts on aquatic ecology. Catchment management strategies therefore frequently need to include provision for the control of sediment mobilisation and delivery. The sediment budget concept provides a valuable framework for assisting the management and control of diffuse source sediment pollution and associated problems, by identifying the key sources and demonstrating the importance of intermediate stores and the likely impact of upstream mitigation strategies on downstream suspended sediment and sedimentassociated contaminant fluxes. Accordingly, the utility of the sediment budget concept for catchment management is further discussed, by introducing examples from several contrasting river basins. Keywords: Sediment budget Catchment management Sediment sources Sediment stores Sediment yields
Termite-induced heterogeneity in African savanna vegetation: mechanisms and patterns
(Wiley online, 2010-07-08) Sileshi, Gudeta W.; Arshad, M. A.; Konaté, Souleymane; Nkunika, Philip O.Y.
Objectives: To (1) assess the strength of evidence for the role of termites in vegetation heterogeneity in African savannas, and (2) identify the mechanisms by which termites induce such heterogeneity. Location: African savannas. Methods: We conducted a review of the literature, a meta-analysis and qualitative systems analysis to identify mechanisms to explain the observed patterns. Results: The review provided evidence for termite-induced heterogeneity in floristic composition and vegetation patterning in savannas across Africa. Termites induced vegetation heterogeneity directly or indirectly through their nest-building and foraging activities, associated nutrient cycling and their interaction with mammalian herbivores and fire. The literature reviewed indicated that termite mounds essentially act as islands of fertility, which are responsible for ecosystem-level spatial heterogeneity in savannas. This was supported by the meta-analysis, which demonstrated that mounds of Ancistrotermes, Macrotermes, Odontotermes (family Macrotermitinae), Cubitermes (family Termitinae) and Trinervitermes (Nasutitermitinae) are significantly enriched in clay (75%), carbon (16%), total nitrogen (42%), calcium (232%), potassium (306%) and magnesium (154%) compared to the surrounding savanna soil. Conclusions: Termite activity is one of the major factors that induce vegetation patterning in African savannas. The implications of this are discussed and research questions for future studies and modelling efforts are indicated.
Handbook
(2012-05-18) Physics, UNZA
Physics is the most fundamental of the Natural Sciences. It is the parent science of Biology, Chemistry, Geology and Engineering, which are but specialisations in areas, which are ultimately a part of Physics. For this reason, the Physics Department occupies an important place in the School of Natural Sciences. A basic level of Physics is required by anyone who wishes to study any science subject or Mathematics. The purpose of the Physics first-year courses is to offer this foundation.
Termite management in tropical agroforestry
(University of Zambia Press, 2013) Nkunika, Philip Obed Yobe
This book is intended to be used as a guide to management of termites in agroforestry and farmsteads where termites pose serious problems. Emphasis is placed on tropical agroforestry and more specifically in Africa. However, it is also hoped that the book will be of use in other continents where termites pose problems. It has been written in response to the growing need to improve understanding of termite problems and taking appropriate action based on such knowledge. In the past, blanket recommendations for termite control have resulted in inefficient and unsustainable use of resources and have had negative impacts on the environment. Control practices have often been initiated on anecdotal information rather than on sound scientific inquiry into the biology and ecology of the local termite species and their true impact on crops or trees. It is important to note that there is no single method that can be universally recommended for termite control because several species may be found in an area and each species has a unique biology and ecology. Therefore, the level of control depends on the knowledge of the termite species, the tree or crop species, climatic conditions and other environmental factors. Our aim is to promote a more sustainable management of termites, i.e., an approach that ensures (1) control of the pest species without causing ecological damage and loss of the ecosystem services provided by termites, (2) conservation of the non-pest termite species, and (3) utilisation of termites and associated resources without exhausting them. This can be achieved through adequate understanding of termite biology and application of control measures based on ecological principles. The intended users of this manual are farmers (subsistence as well as commercial), extension officers, researchers, pest control operators and students. The aim is to provide basic information on termites and help people to take more informed actions to manage termites in agroforestry. This book is presented in six chapters. Chapter one introduces the concept of agroforestry, agroforestry practices, different types of agroforestry, advantages of agroforestry and introduces the subject of termite management in agroforestry. Chapter two provides a description of the biology of termites including their social organisation, life cycle, nesting behaviour, classification and food. Chapter three provides a summary of the beneficial aspects of termites. Chapter four provides a brief discussion on common pestiferous termites and the damage they cause to crops and trees. Chapter five focuses on principles that should be followed for sustainable management of pestiferous termites in agroforestry with less emphasis on control and Chapter six ends with concluding remarks and prods scholars to do further research in this much neglected, but very important area.
Understanding controls on biotic assemblages and ecological status in Zambian rivers for the development of sustainable monitoring protocols
(Geophysical Research Abstracts, 2014) Sichingabula, Henry
The water resources of Zambia are likely to experience increasing multiple pressures in the future as a result of very high predicted population growth, industrial development, land use change, and potentially, altered regional rainfall patterns. It is well known that rivers in tropical regions typically have a rich biodiversity, controlled in part by inter-annual variability in climate and discharge, and in part by local catchment conditions. However, till recently little country-wide work had had been carried out on the biota of Zambian rivers, and little was therefore known about the ecological status, or degree of catchment alteration of many of the rivers.To underpin sustainable water management, protocols have been developed to assess the ecological status of Zambian rivers.
Sedimentation and its effects on selected small dams east of Lusaka, Zambia
(Academic star publishing company, 2015) Sichingabula, Henry
In Zambia, the need to conserve water resources has resulted in the construction of small dams. However, small dams are adversely impacted by sedimentation. The aim of this study was to assess the water storage capacity loss for the selected small dams east of Lusaka Zambia. These included Lwiimba, Silverest, Morester and Katondwe dam. Data was collected by bathymetric survey for each small dam using hydrographic boat with echo sounding. The initial storage capacity data were collected from the dam owners and through interviews with key informants on the effects of sedimentation on dam uses and on the existence of sediment control measures. Results of the study revealed that the measured reservoir storage capacities in year 2015 for Lwiimba, Silverest, Morester and Katondwe dams were 101,051.43 m3, 379,480.00 m3, 14,724.88 m3 and 10,714.88 m3, respectively. The estimated rates of sedimentation for Silverest was 14,595.40 m3yr-1; Lwiimba (2,200.99 3yr-1); Katondwe (283.92 m3yr-1), and Morester (251.01 m3yr-1). These rates of sedimentation has led to reservoir capacity storage losses of 99,044.57 m3; 379,480.5 m3; 13,805.68 m3 and 9,937.12 m3 for Lwiimba, Silverest, Morester and Katondwe, respectively, with the general consequences of reservoir drying especially in the dry season. Natural vegetation is the main sediment control measure used in the catchments. It is concluded that the studied small dams East of Lusaka are seriously affected by sedimentation. This calls for periodic dredging of deposited sediment in order to increase reservoir storage capacity for sustainable use of the water resource in small dams’ impoundments. Key words: sedimentation, bathymetric survey, small dam, reservoir capacity, erosion
Evaluating ceres-maize model using planting dates and nitrogen fertilizer in Zambia
(Journal of Agricultural Science, 2015-02-15) Sichingabula, Henry
A field experiment was conducted during the 2013/2014 season to evaluate the performance of CERES-maize model in simulating the effect of date of planting, nitrogen fertilizer and root-zone soil water profile on growth and yield of maize (Zea mays L.) at the Field Research Station of the School of Agricultural Sciences, University of Zambia, Zambia (15o23.6859′S, 28o20.226′E; 1,261 m.a.s.l). The experimental design was a split plot with three replicates, three planting dates (November 24, December 8, and December 22) assigned to main plots and two nitrogen fertilizer rates (112 and 168 kg N ha-1) assigned to sub-plot. Phenological stages and aboveground biomass were used for model evaluation and these were observed at vegetative and reproductive stages. Soil water profiles were monitored using the Diviner 2000 Probe. Planting date significantly affected grain and biomass yield at P < 0.05. The coefficients of variation for grain and biomass yield were below 12% and considered efficient. The Generalized Likelihood Uncertainty Estimation (GLUE) programme was used to estimate the genetic coefficients for the CERES-maize model. The model’s prediction of plant emergence (±1 days), time to anthesis (≥ −3 ≤ ±1 days) and maturity (≥ −4 ≤ 6 days) was good. Simulation of biomass (RMSE=1135 kg/ha, d=0.96, EF=0.86) was reasonably accurate while leaf area index (d = 0.54, EF = −0.65) was simulated with less accuracy due to poor d-stat and forecasting efficiency. The model’s simulation of grain yield was fair (NRMSE = 21.4%) while soil root water availability demonstrated that substantial potential yield may have been lost due to water stress. The results showed that the model can be used to accurately determine optimum planting date, biomass yield and nitrogen fertilizer rates with reasonable accuracy. Keywords: biomass, calibration, CERES-maize, fertilizer application rate, GLUE, tops weight
Resistance status of ticks (Acari; Ixodidae) to amitraz and cypermethrin acaricides in Isoka District, Zambia
(University of Zambia, 2015-08) Muyobela, Jackson; Nkunika, Phillip Obed Yobe; Mwase, Enala Tembo
This study was designed to obtain data on the farmer’s approach to tick control and to determine whether Rhipicephalus appendiculatus Neuman, Amblyomma variegatum (Fabricius), and Rhipicephalus (Boophilus) microplus (Canestrini) were resistant to amitraz and cypermethrin acaricides, in Isoka District, Zambia. Prevailing tick control practices were documented by administering a semi-structured questionnaire to 80 randomly selected smallholder livestock farmers from four agricultural camps (Longwe, Kantenshya, Kapililonga, and Ndeke) in Isoka District. Modified larval packet test (LPT) bioassay experiments were used to determine the resistance status of the common tick species against amitraz and cypermethrin acaricides. Fifty percent of respondents practiced chemical tick control with amitraz (27 %) and cypermethrin (23 %) being the acaricides in use, and were applied with knapsack sprayers. Less than 3 l of spray wash per animal was used which was considerably lower than the recommended delivery rate of 10 l of spray wash per animal. No significant susceptibility change to amitraz at 95 % confidence level was observed in R. appendiculatus and A. variegatum against amitraz. However, a significant change in the susceptibility of R. (Bo.) microplus tested with amitraz was detected at 95 % confidence. The test population had a lower susceptibility (LD50 0.014 %; LD90 0.023 %) than the reference population (LD50 0.013 %; LD90 0.020 %). The results indicated that resistance to amitraz was developing in R. (Bo.) microplus. For cypermethrin, no significant susceptibility change at 95 % confidence was observed in any of the three species and thus resistance to this chemical was not observed. Keywords Acaricide resistance . Tick control . Bioassay . Susceptibility .Amitraz . Cypermethrin
In vitro acaricidal activity of Bobgunnia madagascariensis desv,against Amblyomma variegatum (Fabricius) (Acari:Ixodidae)
(Springer, 2016) Muyobela, Jackson; Nkunika, Phillip Obed Yobe
The Zambian macrophyte trophic ranking scheme, ZMTR:a new biomonitoring protocol to assess the trophic status of tropical Southern African rivers
(Elsevier, 2016) Sichingabula, Henry
tThe Zambian macrophyte trophic ranking system (ZMTR) is a new bioassessment scheme to indicate thetrophic status of tropical southern African river systems. It was developed using a dataset of 218 samplesof macrophytes and water chemistry, collected during 2009–2012, from river sites located in five worldfreshwater ecoregions primarily represented in Zambia. A typology based on these ecoregions, and three stream order categories, was used to determine soluble reactive phosphate (SRP) reference conditions. Zambian Trophic Ranking Scores (ZTRSsp) were calculated for 156 species, using direct allocation fromSRP data for 80 species, in samples for which sufficient available SRP data existed. An indirect quantitative procedure, based upon occurrence of species in six sample-groups, of differing mean SRP status, produced by TWINSPAN classification, allocated provisional ZTRSsp values for the remaining 76 species. Additional data for nitrate, pH, alkalinity and conductivity were used to help assess the trophic preferences of macrophyte species showing differing ZTRSsp values. ZMTR samplevalues were calculated as the meanZTR Sspscore of species present per sample. ZMTR indicated trophic status reasonably accurately for83.1% of Zambian samples, and for all samples within a test dataset from Botswanan rivers. Examples of application of the methodology, and its potential for hindcasting river trophic status are provided. The scheme currently underestimates highly-enriched conditions, and, to a lesser extent, overestimates the trophic status of some very low-nutrient rivers, but at this pilot stage of development it generally predicts the trophic status of tropical southern African river systems quite well. Keywords:Biomonitoring,Aquatic macrophytes,Eutrophication,Tropical Africa Southern African river assessment scheme

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