Department of Biological Sciences

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Analysis of Structure and Diversity of the Kilengwe Forest in the Morogoro Region, Tanzania
(International Journal of Biodiversity, 2014) Kacholi, David Sylvester
This study investigates the structure, species composition, and diversity of a section of the Kilengwe Forest in Tanzania. In order to accomplish the proposed objectives, 18 plots of 20m× 20m were randomly established in the forest and the number of tree species in each plot was identified and counted. The most important families and species were determined using importance value indices at the respective taxonomic levels. Diversity was measured using the Shannon-Wiener and Fisher alpha diversity indices. A total of 276 stems/ha representing 93 species/ha within 26 families were documented from 0.72 ha. Fabaceae and Julbernadia globiflora were the dominant family and species, respectively. Seventy-eight percent of the total species were rare.The average basal area of the forest was 7.1m2/ha. The Shannon-Wiener index (4.02) and Fisher’s alpha diversity (35.5) indicated high species diversity within the forest. The species-area and species-abundance curves revealed an escalating trend implying that more sampling efforts could result in a higher number of species existing in the forest. The size class distribution displayed a reverse J-shaped pattern; however, the larger size classes DBH >50 cm were not represented.The study suggests the necessity for anthropogenic disturbance control as this is the major source of forest degradation in the studied area.
Are small-scale coffee farmers in Tanzania safe from potential agrochemical health hazards? Week in Review, Biosciences for Farming in Africa (B4FA).
(Biosciences for Farming in Africa, 2016-01-15) Bakuza, Jared S.
http://b4fa.org/are-small-scale-coffee-farmers-in-tanzania-safe-from-potential-agrochemical-health-hazards/
Assessing S. mansoni prevalence in Biomphalaria snails in the Gombe region of Western Tanzania: the importance of DNA sequence data for clarifying species identification
(Parasite & Vectors, 2017) Bakuza, Jared S.; Gilespie, Robert; Nkwengulila, Gamba; Adam, Aileen; Kilbride, Elizabeth; Mable, Marble K.
Assessment of Tree Species Richness, Diversity, Population Structure and Natural Regeneration in Nongeni Forest Reserve in Morogoro Region, Tanzania
(Tanzania Journal of Science, 2019) Kacholi, David Sylvester
This study examined tree species richness, diversity, population structure and regeneration in Nongeni forest reserve, Morogoro, Tanzania. The study deployed plot sampling technique whereby a total of 20 plots of 0.05 ha each were randomly established in the forest. All species and individuals encountered in each plot were counted, identified and DBH measured. A total of 751 individuals/ha representing 24 species belonging to 11 families were recorded. Family Fabaceae was dominant with 9 species. The Shannon-Wiener, Margalef, Simpson‟s and Pielou J index were calculated as 2.667, 3.474, 10.58 and 0.839, respectively. The Diplorhynchus condylocarpon (52.18) was the dominant species in terms of species importance value index (IVI) followed by Antidesma venosum (27.40) and Stereospermum kunthianum (21.16). The forest mean basal area was 10.80 m2/ha whereby D. condylocarpon (2.26 m2/ha) had highest value followed by Julbernardia globiflora (1.36 m2/ha). Of the observed species, 12.5% exhibited good regeneration, 45.8% poor regeneration, 29.2% new regeneration and 12.5% displayed fair/hampered regeneration pattern. Also, 29.1% of the species displayed both poor regeneration pattern and low IVI. The study concludes that the forest was rich in tree species and had good regeneration. However, conservation attention and proper management strategies for the species that exhibited poor regeneration and low IVI is imperative.
Changes in forest composition, edaphic factors and exploitation pressure between edge and interior habitats in the Kimboza forest in Morogoro Region, Tanzania
(Journal of Education, Humanities and Sciences, 2016) Kacholi, David Sylvester
Biodiversity loss is linked to the destruction and fragmentation of tropical forest ecosystems. This study was conducted at Kimboza forest located in Morogoro region, Tanzania. The main goal was to compare the forest edge and interior habitats in terms of tree species richness, stand structure, soil moisture, organic matter and exploitation pressure. All trees with DBH ≥ 10cm were sampled from 6 plots of 0.04ha placed in each habitat. A total of 217 individuals from 49 tree species and 21 families were recorded in both habitats. Of the total recorded species, 37% were common, while 22% and 41% occurred exclusively at the edge and interior, respectively. The species richness, tree density, basal area, soil organic matter and moisture were significantly higher in the forest interior than the edge. On the contrary, the number of stumps per hectare was significantly higher in the edge (3.8) than interior (1.8). The Sørensen coefficient of similarity among the two habitats was 0.54, signifying the presence of uniqueness among the habitats. In summary, the findings suggest that the two habitats are unique and different in terms of species composition, species richness, stand structure, soil moisture, organic matter and anthropogenic exploitation pressure.
Comparison of detection methods to estimate asexual Plasmodium falciparum parasite prevalence and gametocyte carriage in a community survey in Tanzania
(Springer Nature, 2014-11-18) Mwingira, Felista; Genton, Blaise; Kabanywanyi, Abdu-Noor M; Felger, Ingrid
Background The use of molecular techniques to detect malaria parasites has been advocated to improve the accuracy of parasite prevalence estimates, especially in moderate to low endemic settings. Molecular work is time-consuming and costly, thus the effective gains of this technique need to be carefully evaluated. Light microscopy (LM) and rapid diagnostic tests (RDT) are commonly used to detect malaria infection in resource constrained areas, but their limited sensitivity results in underestimation of the proportion of people infected with Plasmodium falciparum. This study aimed to evaluate the extent of missed infections via a community survey in Tanzania, using polymerase chain reaction (PCR) to detect P. falciparum parasites and gametocytes. Methods Three hundred and thirty individuals of all ages from the Kilombero and Ulanga districts (Tanzania) were enrolled in a cross-sectional survey. Finger prick blood samples were collected for parasite detection by RDT, LM and molecular diagnosis using quantitative 18S rRNA PCR and msp2 nPCR. Gametocytes were detected by LM and by amplifying transcripts of the gametocyte-specific marker pfs25. Results Results from all three diagnostic methods were available for a subset of 226 individuals. Prevalence of P. falciparum was 38% (86/226; 95% CI 31.9–44.4%) by qPCR, 15.9% (36/226; 95% CI 11.1–20.7%) by RDT and 5.8% (13/226; 95% CI 2.69- 8.81%) by LM. qPCR was positive for 72% (26/36) of the RDT-positive samples. Gametocyte prevalence was 10.6% (24/226) by pfs25-qRT-PCR and 1.2% by LM.
Copper levels in three commonly edible fruits: Are consumers at risk?
(JOURNAL OF AGRICULTURE AND APPLIED BIOLOGY, 2021) Minati, Sahu; Kacholi, David Sylvester
This study aimed to investigate levels of copper in three commonly edible fruits, namely, Lycopersicon esculenta (tomato), Citrullus la-natus (watermelon) and Cucumis sativus (cucumber) traded in Dar es Salaam city. Also, the study scrutinized risk associated with heavy metal intake in the fruits. The fruits were collected from Buguruni Market, one of the biggest markets in the city, and thereafter, were processed, and analyzed to determine copper levels. The average daily intake and human health risk indices were calculated based on the obtained copper levels. The findings revealed that the mean levels and average daily intake in L. esculenta (0.3267 mg kg-1, 0.0279 mg kg-1 person-1) and C. lanatus (0.2523 mg kg-1, 0.0216 mg kg-1 person-1) did not differ considerably (p = 0.05) from each other while the two fruits had significantly higher values than C. sativus (0.1610 mg kg-1, 0.0137 mg kg-1 person-1). The copper levels and average daily intake values were below WHO/FAO and Tanzania Bureau of Standards per-missible limits. The human health index (HRI) was in the order: L. es-culenta > C. lanatus > C. sativus and all the values were less than unit, suggesting that there is no health risk from consuming the fruits. Con-cerning copper levels, the study concludes that the fruits are safe for human consumption.
Cytomegalovirus Infection Impairs Immune Responses and Accentuates T-Cell Pool Changes Observed in Mice With Aging
(2012-07) Cicin-Sain, Luka; Brien, James D.; Uhrlaub, Jennifer L.; Drabig, Anja; Marandu, Thomas F.; Zugich, Janko N.
Prominent immune alterations associated with aging include the loss of naïve T-cell numbers, diversity and function. While genetic contributors and mechanistic details in the aging process have been addressed in multiple studies, the role of environmental agents in immune aging remains incompletely understood. From the standpoint of environmental infectious agents, latent cytomegalovirus (CMV) infection has been associated with an immune risk profile in the elderly humans, yet the cause-effect relationship of this association remains unclear. Here we present direct experimental evidence that mouse CMV (MCMV) infection results in select T-cell subset changes associated with immune aging, namely the increase of relative and absolute counts of CD8 T-cells in the blood, with a decreased representation of the naïve and the increased representation of the effector memory blood CD8 T-cells. Moreover, MCMV infection resulted in significantly weaker CD8 responses to superinfection with Influenza, Human Herpes Virus I or West-Nile-Virus, even 16 months following MCMV infection. These irreversible losses in T-cell function could not be observed in uninfected or in vaccinia virus-infected controls and were not due to the immune-evasive action of MCMV genes. Rather, the CD8 activation in draining lymph nodes upon viral challenge was decreased in MCMV infected mice and the immune response correlated directly to the frequency of the naïve and inversely to that of the effector cells in the blood CD8 pool. Therefore, latent MCMV infection resulted in pronounced changes of the T-cell compartment consistent with impaired naïve T-cell function.
Density and Aboriginal Uses of Wild Tree Species in Milawilila Forest Reserve in Morogoro Region, Tanzania
(College of Natural and Applied sciences, University Of Dar es Salaam, 2020-03) Kacholi, David Sylvester
This study assessed density and local uses of wild tree species in Milawilila forest reserve, Morogoro rural district. A total of six transects were set in the forest for assessing density and diversity of trees. In each transect, three plots of 20 m x 20 m were established and all trees with Diameter at Breast Height (DBH) ≥ 10 cm were identified, counted and DBH recorded in each plot. A semi structured questionnaire was used to obtain data on the use of tree species by the locals. Data were analyzed using Microsoft Excel and Statistical Package for Social Science software. A total of 172 trees/ha belonging to 20 species and 15 families were recorded in the forest. Among the families, Fabaceae was the richest family with 3 species, followed by Annonaceae and Cluciaceae with 2 species each. The most abundant species were Xylopia parviflora, Ehretia amoena and Diospyros squarrosa, which contributed 46% of the total tree density in the forest while the remaining 17 species contributed 54%. The Shannon-Wiener diversity index and basal area of the forest was 2.62 and 13.0 m2/ha, respectively. The forest exhibited good regeneration pattern. The proportion of tree species used for medicines was 76%, constructions 60%, fuelwood 56%, crafts 52%, and food/fodder 28%. The three species with high citation index were Albizia glaberrima (3.58), Annona senegalensis (3.38) and Scorodophleous fischeri (3.16). Since, majority of the observed species were less dense, the study suggests planting of the wild tree species should be prioritized to guarantee sustainability of the forest reserve and viable supply of forest products and services to the community.
Distribution Patterns of Gastrointestinal Parasites in Vervet Monkeys (Chlorocebus pygerythrus) at Gombe National Park, Tanzania
(Tanzania Journal of Science, 2018) Bakuza, Jared S.
Vervet monkeys at Gombe National Park in western Tanzania constitute a key component of the park’s ecosystem through interactions with other animals and people in the area. However, the parasite fauna of these animals has not been investigated. Thus, 21 faecal samples obtained from the animals in September 2010 were examined for parasites using formol-ethyl technique. The parasites observed included Trichuris spp., Physaloptera spp., hookworms and unidentified nematodes. While egg counts for unidentified nematodes did not vary with vervet monkey communities (z = 0.759, p = 0.448), other parasites were significantly higher among vervets at north of the park near Mwamgongo village compared to those at southern park border close to Mtanga village (Trichuris spp.: z = 2.443, p = 0.0146; Hookworms: z = 2.084, p = 0.0371). This is the first baseline study on vervet monkey parasites at Gombe and it broadens our understanding of the animals’ ecology and health. The observed parasites namely Trichuris and hookworms are also common in human populations in the area, and this suggests a potential health risk given the existing animal-human interactions. This stresses the need to better understand how these findings
Diversity, abundance, and structure of tree communities in the Uluguru forests in the Morogoro region, Tanzania
(Journal of Forestry Research, 2015-09) Kacholi, David Sylvester; Whitbread, Anthony Michael; Worbes, Martin
Uluguru forests are globally recognized as important biodiversity hotspots, but anthropogenic pressure threatens their value. This study examined species diversity, abundance, and structure of trees in the Uluguru forests. All trees of diameter at breast height (DBH) C 10 cm were inventoried in seven forests ranging from 3 to 995 ha in area. A total of 900 stems, 101 species and 34 families were inventoried. Fabaceae was the most speciose family.Ehretia amoena Klotzsch was the most abundant species with relative abundance of 9.22 %. The forests differed significantly in species richness (26–93 species/ha), tree density (85–390 stems/ha), basal area (3–24 m2/ha) and Shannon-Wiener diversity (2.50–4.02). Forest area was significantly and positively correlated with species richness (r = 0.92) and species diversity (r = 0.95). Tree density showed significant positive correlation with species richness (r = 0.80) and basal area (r = 0.85). Milawilila and Nemele forests had highest floristic similarity (0.55) followed by Kimboza and Kilengwe (0.54) while the rest had similarity coefficients of less than 0.50. Despite legislative protection, many forests remain at risk and therefore the possibility to conserve highly valuable tree species via enhanced protection or cultivation must be considered.
Edge-Interior Disparities in Tree Species and Structural Composition of the Kilengwe Forest in Morogoro Region, Tanzania
(ISRN Biodiversity, 2014) Kacholi, David Sylvester
A survey to determine the variation in species and structural composition of trees along the edge-interior gradient was done in the Kilengwe forest inMorogoro region, Tanzania.The forest was categorized into three habitats, namely, edge (0–100m), intermediate (100–200 m), and interior (>200m) depending on the distance from the forest margin. A total of six plots of 0.04 ha each were randomly placed in each of the habitats whereby all trees with DBH ≥ 10 cm were inventoried. A total of 67 species representing 26 families were recorded. Fabaceae was the most speciose and abundant family. Brachystegia spiciformis was the most abundant species. Of the recorded species, 10.45% were common in the three habitats while 8.95%, 13.43%, and 26.86% occurred exclusively to the edge, intermediate, and interior habitats, respectively. The forest interior was significantly rich in terms of species richness, diversity, density, and basal area than the edge and intermediate habitats.The edge had significantly higher number of stumps/ha. In summary, the results suggest that edge/intermediate and interior are contrasting habitats in terms of tree species richness, diversity, and structural composition. Moreover, the forest edge and intermediate habitats were found to be characterized by high anthropogenic activities compared to the forest interior habitat.
Effectiveness of intermittent preventive treatment with sulfadoxine–pyrimethamine during pregnancy on placentalmalaria, maternal anaemia and birthweight in areas with highand low malaria transmission intensity in Tanzania
(2014 John Wiley & Sons Ltd, 2014-09) Mosha, Dominic; Chilongola, Jaffu; Ndeserua, Rabi; Mwingira, Felista; Genton, Blaise
objective To assess the effectiveness of IPTp in two areas with different malaria transmission intensities. methods Prospective observational study recruiting pregnant women in two health facilities in areas with high and low malaria transmission intensities. A structured questionnaire was used for interview. Maternal clinic cards and medical logs were assessed to determine drug intake. Placental parasitaemia was screened using both light microscopy and real-time quantitative PCR. results Of 350 pregnant women were recruited and screened for placental parasitaemia, 175 from each area. Prevalence of placental parasitaemia was 16.6% (CI 11.4–22.9) in the high transmission area and 2.3% (CI 0.6–5.7) in the low transmission area. Being primigravida and residing in a high transmission area were significant risk factors for placental malaria (OR 2.4; CI 1.1–5.0; P = 0.025) and (OR 9.4; CI 3.2–27.7; P < 0.001), respectively. IPTp was associated with a lower risk of placental malaria (OR 0.3; CI 0.1–1.0; P = 0.044); the effect was more pronounced in the high transmission area (OR 0.2; CI 0.06–0.7; P = 0.015) than in the low transmission area (OR 0.4; CI 0.04–4.5; P = 0.478). IPTp use was not associated with reduced risk of maternal anaemia or low birthweight, regardless of transmission intensity. The number needed to treat (NNT) was four (CI 2–6) women in the high transmission area and 33 (20–50) in the low transmission area to prevent one case of placental malaria. conclusion IPTp may have an effect on lowering the risk of placental malaria in areas of high transmission, but this effect did not translate into a benefit on risks of maternal anaemia or low birthweight. The NNT needs to be considered, and weighted against that of other protective measures, eventually targeting areas which are above a certain threshold of malaria transmission to maximise the benefit.
Estimating the prevalence and intensity of Schistosoma mansoni infection among rural communities in Western Tanzania: The influence of sampling strategy and statistical approach
(PLOS Neglected Tropical Diseases, 2017-09-21) Bakuza, Jared S.; Nkwengulila, Gamba; Denwood, Matthew J.; Mable, Barbara K
Background Schistosoma mansoni is a parasite of major public health importance in developing countries, where it causes a neglected tropical disease known as intestinal schistosomiasis. However, the distribution of the parasite within many endemic regions is currently unknown, which hinders effective control. The purpose of this study was to characterize the prevalence and intensity of infection of S. mansoni in a remote area of western Tanzania. Methodology/Principal findings Stool samples were collected from 192 children and 147 adults residing in Gombe National Park and four nearby villages. Children were actively sampled in local schools, and adults were sampled passively by voluntary presentation at the local health clinics. The two datasets were therefore analysed separately. Faecal worm egg count (FWEC) data were analysed using negative binomial and zero-inflated negative binomial (ZINB) models with explanatory variables of site, sex, and age. The ZINB models indicated that a substantial proportion of the observed zero FWEC reflected a failure to detect eggs in truly infected individuals, meaning that the estimated true prevalence was much higher than the apparent prevalence as calculated based on the simple proportion of non-zero FWEC. For the passively sampled data from adults, the data were consistent with close to 100% true prevalence of infection. Both the prevalence and intensity of infection differed significantly between sites, but there were no significant associations with sex or age. Conclusions/Significance Overall, our data suggest a more widespread distribution of S. mansoni in this part of Tanzania than was previously thought. The apparent prevalence estimates substantially underestimated the true prevalence as determined by the ZINB models, and the two types of sampling strategies also resulted in differing conclusions regarding prevalence of infection. We therefore recommend that future surveillance programmes designed to assess risk factors should use active sampling whenever possible, in order to avoid the self-selection bias associated with passive sampling.
Ethnobotanical survey of medicinal plants used by traditional healers in managing Gonorrhoea and Syphilis in Urambo District, Tabora Region, Tanzania
(Taylor and Francis, 2022-02-18) Kacholi, David Kacholi; Amir, Halima Mvungi
Medicinal plants used by traditional healers (THs) in managing gonorrhea and syphilis in Urambo District, Tabora Region, Tanzania, were documented. A semi-structured questionnaire was used to gather information on the use of medicinal plants. The findings revealed that 33 medicinal plants belonging to 18 families were used by the THs to manage gonorrhea and/or syphilis in Urambo District. Among the listed plants, Ximenia caffra, Friesodielsia obovata and Clerodendrum myricoides were frequently used by THs to manage gonorrhea while Ozoroa reticulata, Catunaregam spinosa, Annona senegalensis and Aloe vera were used to manage syphilis. Cassia abreviata, Strychnos spinosa, Strychnos potatorum and Entanda abyssinica were frequently used for the management of both ailments. Five species namely Oldfieldia dactylophylla, Flaucortia indica, Strophanthus eminii, Musa sapeintum and Phyllanthus engleri were recorded for the first time in the country’s ethnobotanical literature as a treatment of STIs. Many of the recorded plants also possessed antimicrobial properties.
Examining Career Orientations Of Information Systems Personnel in an Emerging Economy Context
(2008-12) Mgaya, Klodwig V.; Uzoka, Faith M. E.; Kitindi, Ernest G.; Shemi, Alice
A number of studies on career orientations of information systems (IS) personnel have focused on developed countries. This study attempts to examine career anchors of IS personnel from the perspective of a developing country, Botswana. The results of the study show that IS personnel in Botswana exhibit career orientations similar to those identified in literature. However, there are some variations, which are attributed to cultural and socio-economic peculiarities. The study indicates that life style does not feature as a significant career anchor in Botswana. The dominant career anchors include organizational stability (security) and sense of service (service). Gender, age, and educational qualifications tend to moderate the career anchors significantly; thus creating a partition of the anchors across demographic groups.
Extent of morbidity associated with schistosomiasis infection in Malawi: a review paper.
(Infectious Diseases of Poverty, 2015-05) Mtethiwa, Austin; Nkwengulila, Gamba; Sikawa, D.; Kazembe, A.
Data on the extent of the burden due to schistosomiasis is sparse in most Sub-Saharan African countries. However, this data is crucial for triggering medical attention. A review of extent of morbidity and determinants associated with schistosomiasis in Malawi was therefore conducted to quantify the infection in order to concretise the need for medical intervention. A systematic and traditional search strategy was used to find literature for the review, whilst exclusion and inclusion criteria were used to identify appropriate articles. Logistic regression curves of epidemiological model Y = (a + bxc)/(1 + bxc) and the recommendation that schistosomiasis prevalence can be used to estimate morbidity were employed to quantify morbidity at various infection stages. Morbidity was quantified as a direct proportion of the population and the respective national schistosomiasis prevalence. Findings showed that both S. mansoni and S. haematobium are present in Malawi with the latter highly prevalent (50%). Furthermore, out of the estimated population of 16,829 million, approximately 8.4 million have schistosomiasis, with about 4.4 million of these aged 18 years and below. The most frequent manifestation is Katayama syndrome, while ascites is the lowest, impacting about 3.0 million and 960 individuals, respectively. Localised studies on association of schistosomiasis infection to risk factors such as occupation, age and gender found odds ratio (OR) ranging from 1.29 to 5.37. Morbidity due to schistosomiasis is high in Malawi. It is therefore recommended that a more detailed study on the determinants of high schistosomiasis and re-evaluation of the current control measures be conducted if the current morbidity statistics are to be remarkably reduced
Floristic Composition, Diversity and Structure of the Kimboza Forest in Morogoro Region, Tanzania
(Journal of Education, Humanities and Sciences, 2013) Kacholi, David Sylvester
Kimboza forest reserve in Morogoro region, is an important biodiversity hotspot among the Eastern Arc forests of Tanzania. High population pressure and encroachment threatens its conservation values. This is based on a study which aimed at investigating the composition, diversity, and structure of the tree community in the forest. All trees with DBH ≥ 10cm were inventoried from 0.72ha in a total of 18 plots of 20m × 20m placed randomly from the forest edge to the interior. Most important families and species were determined using familial importance value (FIV) and species importance value (IVI) indices, respectively. Diversity was analyzed using species richness, Shannon-Wiener, Fisher-α, and Simpson’s indices. A total of 52 species belonging to 22 families were identified. The family Fabaceae had the highest FIV (66.70) and species richness (15 species) while Khaya anthotheca had the highest IVI value (48.11). The Shannon-Wiener (3.40), Simpson (20.60), and the Fisher-α (18.80) indices were very high signifying high floristic diversity within the forest. 69% of the species were rare, occurring in less than 20% of the surveyed plots. The mean density and basal area of trees were 390 stems ha-1 and 24 m2 ha-1, respectively. The species accumulation curve revealed an escalating trend suggesting that more sample plots could result to a number of species in the forest. In summary, the study suggests for proper management, protection, and wise utilization of the forest resources so that it sustains its original biodiversity and ecological processes for future generations.
Floristic Similarity and Diversity Gradients in the Eastern Arc and Coastal Forests of Tanzania
(Dar es Salaam University College of Education (DUCE), 2018-12-19) Kacholi, David Sylvester
The Eastern Arc and Coastal forests of Tanzania are biodiversity hotspots, centres of endemism, and highest priority ecosystems for biodiversity conservation worldwide. But, their floristic similarity and species diversity gradients over geographical distances and longitudinal locations, respectively, are poorly understood. Thus, this study investigates the relationship between floristic similarity and geographical distances, as well as species diversity and longitudinal locations among the forests. A total of 37 inventories from the Eastern Arc and Coastal forests of Tanzania were selected based on inventories with minimum diameter at breast height (DBH) ≥ 10cm), and identification of trees done at species level. The floristic similarity was determined using the Sørensen’s similarity coefficient. The Pearson correlation test was used to study differences between floristic similarities and geographical distances, as well as species diversity and longitudinal location. The findings revealed three clusters of forests assembled due to their geographical proximity. The correlation between geographical distances and floristic similarities revealed a significant negative association (n = 528, R2 = 0.1821, p < 0.001), while species diversity and longitudinal location of forests had a significant positive correlation (n = 37, R2 = 0.5401, P < 0.05). The results suggest that high environmental heterogeneity across the forests should be well thought-out in their management plans to uphold their values
Heavy metals level in Amaranthus species from Chang’ombe-Mchicha Area in Temeke District, Dares- Salaam, Tanzania
(Asian Journal of Chemistry, 2016) Sahu, Minati; Kacholi, David Sylvester
This study focuses on the concentration levels of heavy metals copper, zinc, lead, iron and cobalt in Amaranthus species grown in a local garden located at Chang’ombe-Mchicha area in Temeke District in Dar es Salaam region, Tanzania. The garden is irrigated by wastewater from a stream flowing nearby and which passes through the industrial areas before reaching the garden. The heavy metal levels in the vegetable were determined using Atomic Absorption Spectrophotometer (AAS). The findings revealed leaves to have higher heavy metal concentrations than stems and roots. The average concentration for copper ranged from 1.14 to 1.70 mg/100 g dry weight, zinc 6.87 to 11.59 mg/100 g, iron 13.40 to 33.65 mg/100 g, lead 0.49 to 2.27 mg/100 g and cobalt 0.14 to 0.27 mg/100 g. These values were higher than the provisional maximum tolerable daily intake standards recommended by FAO/WHO codex committee on contaminants in foods. The high observed values put consumers of the vegetable grown in the study area at health risk over time unless urgent and right steps are to be taken by the responsible authority to address this issue. Thus, the findings are important to consumers and policy makers.

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