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Managing invasive plants through a nature-based approach in complex landscapes
Get PDFThis research article published by Elsevier Ltd., 2022Invasive plants are establishing in many protected areas where use of synthetic herbicides is prohibited. We introduce a nature-based approach (NbA) as an alternative to controlling invasives. The integration of NbA into ecosystem conservation provides potential to suppress invasive plants, improve soil cover, increase the diversity of native plants, and ultimately ensure ecosystem sustainability
Growth performance of the neglected crop Telfairia pedata across elevation and climate gradients in Northern Tanzania
Get PDFThis research article published by Elsevier B.V., 2022Herbaceous vines, including the neglected crop Telfairia pedata, play a key role in small-holder livelihoods of
Eastern Africa. Despite this species’ importance in enhancing agro-biodiversity, little is known about its distri-
bution and growth performance in relation to environmental variables. We collected biophysical and environ-
mental data, i.e., on climate and elevation, for 346 T. pedata vines across four districts of Northern Tanzania from
September, 2019, to February, 2020. The four sites included Same, Lushoto, Muheza and Arumeru districts. We
found that plants of T. pedata were mainly grown in elevations ranging between 900 to 1800 m above sea level
with annual rainfall regimes of 1000 to 1400 mm. We recorded large abundance of T. pedata in Lushoto (46%)
and Arumeru (28%) and observed that the number of fruits and fruit diameter were both positively correlated
with elevation across the study districts. There was a significant effect of elevation on number of seeds, with
Same district having more seeds across the studied districts. Rainfall had a significant effect on fruit diameter and
number of seeds in the study districts. Furthermore, the tree species Albizia schimperiana was most commonly (in
40% of the cases) associated with T. pedata, followed by Persea americana (14%), and Croton macrostachyus (9%).
We highlight that mountainous regions are ideal for this highly nutritious crop, and that native trees are of high
importance for enriching this vine to current agro-ecosystems. Our findings will increase awareness on the
importance of raising T. pedata crop, livelihood diversification, and increasing biodiversity through production of
this orphan crop in small-holder farms.
1. Introduction
Telfairia pedata (Smiths ex Sim) Hook or oyster nut belongs to Cur-
cubitaceae family, which includes over 700 species and approximately
90 genera (Okoli and Mgbeogu, 1983; Odiaka et al., 2008; Chiamaka
et al., 2020). It is a herbaceous woody vine and dioecious that bears
squash-like fruits with large and nutritious oily seeds, is perennial and
can withstand drought to some extent (Onovo et al., 2010; Ifeanyi-Obi
et al., 2013), (Fig. 1). Telfairia pedata is mostly grown for its oilseeds in
Tanzania including Zanzibar Island, and other African countries
including Angola, Mozambique, coast of Kenya, Uganda and Nigeria
(Schippers, 2000; Odiaka et al., 2008; Odiaka and Odiaka, 2011; Are-
gheore, 2012). The nuts are highly valued by East Africa natives and are
in great demand by breastfeeding mothers (Fubara-Manuel et al., 2012;
Nwonuala and Obiefuna, 2015). These oilseeds are related to pumpkin
seeds (Cucurbita moschata) which are also highly important for their
therapeutic and functional (nutraceutical) values (Dotto & Chacha,
2020). Telfairia pedata nuts are mostly eaten raw or boiled, roasted for
confectionery or grounded into a thick paste for use in staple meals such
as soup thickening (Odiaka et al., 2008; Alegbejo, 2012). It contain
protein, fat, carbohydrates, oleic acid, linoleic acid, stearic acid, pal-
mitic acid, minerals including phosphorus (P), magnesium (Mg), po-
tassium (K), iron (Fe) and calcium (Ca) (Aregheore, 2007; Mwakasege
et al., 2021).
In some cases, Telfairia species provide substantial cash income to
small rural farm families and for biodiversity conservation (Akoroda,
1990; Alegbejo, 2012; Chukwurah et al., 2015). However, despite its
household income generation, nutritional and environmental value, the
cultivation of this crop in Tanzania has been neglected, and little is
known about its distribution, growth performance and constraints. The
climber grows well in presence of hard wood trees or wooden made
structures, and it is regarded as an important component of the rich
* Corresponding author.
E-mail address: [email protected] (P.F. Shayo).
Contents lists available at ScienceDirect
Trees, Forests and People
journal homepage: www.sciencedirect.com/journal/trees-forests-and-people
https://doi.org/10.1016/j.tfp.2022.100216
Received 30 August 2021; Received in revised form 25 January 2022; Accepted 3 February 202
Response surface optimization and modeling in heavy metal removal from wastewater—a critical review
Get PDFThis research article was published by Springer Nature in 2022The existence of hazardous heavy metals in aquatic settings causes health risks to humans, prompting researchers to devise effective methods for removing these pollutants from drinking water and wastewater. To obtain optimum removal efficiencies and sorption capacities of the contaminants on the sorbent materials, it is normally necessary to optimize the purification technology to attain the optimum value of the independent process variables. This review discusses the most current advancements in using various adsorbents for heavy metal remediation, as well as the modeling and optimization of the adsorption process independent factors by response surface methodology. The remarkable efficiency of the response surface methodology for the extraction of the various heavy metal ions from aqueous systems by various types of adsorbents is confirmed in this critical review. For the first time, this review also identifies several gaps in the optimization of adsorption process factors that need to be addressed. The comprehensive analysis and conclusions in this review should also be useful to industry players, engineers, environmentalists, scientists, and other motivated researchers interested in the use of the various adsorbents and optimization methods or tools in environmental pollution cleanup
Impacts of large-scale land acquisitions on smallholder agriculture and livelihoods in Tanzania
Get PDFThis research article was published by IOP SCIENCE, Volume 17, Number 8, 2022Improving agricultural productivity is a foundational sustainability challenge in the 21st century.
Large-scale land acquisitions (LSLAs) have important effects on both well-being and the
environment in the Global South. Their impacts on agricultural productivity and subsequent
effects on farm incomes, food-security and the distribution of these outcomes across households
remain under-investigated. In particular, prior studies do not sufficiently attend to the mechanistic
nature of changes in household agricultural practices that affect LSLA outcomes. To address these
challenges, we use a novel household dataset and a quasi-experimental design to estimate
household-level changes in agricultural productivity and other LSLA outcomes in Tanzania. We
use causal mediation analysis to assess how four common mechanisms—contract farming, land
loss, market access and technology adoption around LSLAs—influence agricultural productivity.
We find that households near LSLAs exhibit 20.2% (95% CI: 3.1%–37.3%) higher agricultural
productivity, primarily due to increased crop prices and farmer selection of high-value crops.
Importantly, the direction and magnitude of effect sizes associated with the different mechanisms
vary. The presence of contract farming explains 18.1% (95% CI: 0.56%, 47%) of the effect size in
agricultural productivity, whereas land loss reduces agricultural productivity by 26.8% (95% CI:
−71.3%, −4.0%). Market access and technology adoption explain little to no portion of the effect
size on agricultural productivity. Despite higher agricultural productivity mediated by contract
farming, we do not find increased household incomes or food security. Plausible explanations
include limited market access, higher crop prices restricting food access and elite capture of
contract farming concentrating income effects to a few households. Our results stand in contrast to
assumptions that technological spillovers occur through LSLAs and are the principal drivers of
LSLA-induced agricultural transformation. We find instead that access to contract farming and
high-value crops lead to greater agricultural productivity, but also that benefits related to these
mechanisms are unequally distributed
Comparative Assessment of UAV and Sentinel-2 NDVI and GNDVI for Preliminary Diagnosis of Habitat Conditions in Burunge Wildlife Management Area, Tanzania
Get PDFThis research article was published by MDPI in 2022Habitat condition is a vital ecological attribute in wildlife conservation and management
in protected areas, including the Burunge wildlife management areas in Tanzania. Traditional
techniques, including satellite remote sensing and ground-based techniques used to assess habitat
condition, have limitations in terms of costs and low resolution of satellite platforms. The Normalized
Difference Vegetation Index (NDVI) and Green NDVI (GNDVI) have potential for assessing habitat
condition, e.g., forage quantity and quality, vegetation cover and degradation, soil erosion and
salinization, fire, and pollution of vegetation cover. We, therefore, examined how the recently emerged
Unmanned Aerial Vehicle (UAV) platform and the traditional Sentinel-2 differs in indications of
habitat condition using NDVI and GNDVI. We assigned 13 survey plots to random locations in the
major land cover types: three survey plots in grasslands, shrublands, and woodlands, and two in
riverine and mosaics cover types. We used a UAV-mounted, multi-spectral sensor and obtained
Sentinel-2 imagery between February and March 2020. We categorized NDVI and GNDVI values into
habitat condition classes (very good, good, poor, and very poor). We analyzed data using descriptive
statistics and linear regression model in R-software. The results revealed higher sensitivity and
ability of UAV to provide the necessary preliminary diagnostic indications of habitat condition. The
UAV-based NDVI and GNDVI maps showed more details of all classes of habitat conditions than
the Sentinel-2 maps. The linear regressions results showed strong positive correlations between the
two platforms (p < 0.001). The differences were attributed primarily to spatial resolution and minor
atmospheric effects. We recommend further studies to test other vegetation indices
Identifying the right plants for diverse biocontrol agents in tropical smallholder bean farming systems
No full textThis research article was published by African Journals OnLine in Vol. 21 No. 1, 2022Biocontrol agents such as predators, parasitoids and pathogens potentially regulate crop
pests populations. The agents feed directly on the pests, oviposit in the pest body or cause disease
in the pest. While biocontrol has become a commercial enterprise in temperate horticulture, there
is much less information on the biocontrol agents present in smallholder agricultural systems
in the tropics and little knowledge about the importance of plant diversity in supporting their
biocontrol activities. A standardized botanical survey walk combined with observations of plant insect interactions was conducted on field margin vegetation of 24 smallholder fields of common
beans (Phaseolus vulgaris L.) in three elevation zones of a tropical ecosystem. Sweep nets were
also used to capture the biocontrol agents and stored in 70% ethanol for detailed taxonomy where
identification in the field was not possible. A wide range of biocontrol agents interacting with the
field margin plants, particularly flowering forbs were revealed. The most preferred field margin
plants were Ageratum conyzoides, Commelina benghalensis, Pennisetum purpureum, Panicum
maximum and Tripsacum sp. The most common biocontrol agents found to interact with the field
margin plants were spiders (Araneae), long-legged flies (Dolichopodidae), predatory and parasitic
wasps (Ichneumonids and braconids), hoverflies (Syrphidae) and assassin bugs (Reduviidae).
Preferences of the biocontrol agents to certain plant species were similar across all three zones,
indicating the importance of such plants in terms of food resources, shelter or nesting sites.
The preference of the biocontrol agents to some plant species indicates the need to identify the
specific benefits of these species to the biocontrol agents to determine whether non-crop habitat
manipulation might enhance natural pest regulation.Biocontrol agents such as predators, parasitoids and pathogens potentially regulate crop
pests populations. The agents feed directly on the pests, oviposit in the pest body or cause disease
in the pest. While biocontrol has become a commercial enterprise in temperate horticulture, there
is much less information on the biocontrol agents present in smallholder agricultural systems
in the tropics and little knowledge about the importance of plant diversity in supporting their
biocontrol activities. A standardized botanical survey walk combined with observations of plant insect interactions was conducted on field margin vegetation of 24 smallholder fields of common
beans (Phaseolus vulgaris L.) in three elevation zones of a tropical ecosystem. Sweep nets were
also used to capture the biocontrol agents and stored in 70% ethanol for detailed taxonomy where
identification in the field was not possible. A wide range of biocontrol agents interacting with the
field margin plants, particularly flowering forbs were revealed. The most preferred field margin
plants were Ageratum conyzoides, Commelina benghalensis, Pennisetum purpureum, Panicum
maximum and Tripsacum sp. The most common biocontrol agents found to interact with the field
margin plants were spiders (Araneae), long-legged flies (Dolichopodidae), predatory and parasitic
wasps (Ichneumonids and braconids), hoverflies (Syrphidae) and assassin bugs (Reduviidae).
Preferences of the biocontrol agents to certain plant species were similar across all three zones,
indicating the importance of such plants in terms of food resources, shelter or nesting sites.
The preference of the biocontrol agents to some plant species indicates the need to identify the
specific benefits of these species to the biocontrol agents to determine whether non-crop habitat
manipulation might enhance natural pest regulation
A simplified non-greenhouse hydroponic system for small-scale soilless urban vegetable farming
Get PDFThis research article was published by Elsevier in 2022Majority of under-developed countries continue to face a challenge of food insecurity around urban areas resulting from factors such as; limited access to arable land. This study aimed at developing a simplified low-tech hydroponic system for growing leafy vegetables alongside testing its economic viability. This was intended to support urban vegetable production and henceforth contributing to food security more so in under-developed states dealing with the challenge of increasing urban population vs. reducing arable land around urban/ peri-urban areas. A hydroponic unit for growing 60 leafy vegetables (using lettuce as a study crop) under non-controlled environmental conditions was designed and developed using low-cost and low-tech materials. Kratky hydroponic method which involves growing crops using water as a media without the need for water pumps and electricity was used. A study was also carried out to assess the profitability of the system. The results indicated a: net present values of 16.37$, internal rate of return of 12.57%, profitability index of 1.1 and non-discounted payback period of approximately 8 months (4 cropping seasons).
These findings showed that the system has the potential to improve urban food production and availability in especially in developing countries in a profitable manner. Vegetable production using the hydroponic system can also contribute to:
•
tachievement of sustainable development goals, 2 (zero hunger) and 3 (good health and wellbeing);
•
improvement in urban agriculture production and income generation among urban farmers;
•
enhanced adoption of low-cost, low-tech, environmental-friendly and sustainable farming systems
Blockchain-based Data Storage Security Architecture for e-Health Care Systems: A Case of Government of Tanzania Hospital Management Information System
Get PDFA research article was published by IJCSNS International Journal of Computer Science and Network Security, VOL.22 No.3, March 2022Health information systems (HIS) are facing security challenges on data privacy and confidentiality. These challenges are based on centralized system architecture creating a target for malicious attacks. Blockchain technology has emerged as a trending
technology with the potential to improve data security. Despite the effectiveness of this technology, still HIS are suffering from a lack of data privacy and confidentiality. This paper presents a blockchain-based data storage security architecture integrated
with an e-Health care system to improve its security. The study employed a qualitative research method where data were collected using interviews and document analysis. Execute-order-validate Fabric’s storage security architecture was implemented through private data collection, which is the combination of the actual private data stored in a private state, and a hash of that private data to guarantee data privacy. The key findings of this research show that data privacy and confidentiality are attained through a private data policy. Network peers are decentralized with blockchain only for hash storage to avoid storage challenges. Cost-effectiveness is achieved through data storage within a database of a Hyperledger
Fabric. The overall performance of Fabric is higher than Ethereum. Ethereum’s low performance is due to its execute-validate
architecture which has high computation power with transaction inconsistencies. E-Health care system administrators should be
trained and engaged with blockchain architectural designs for health data storage security. Health policymakers should be aware of blockchain technology and make use of the findings. The scientific contribution of this study is based on; cost-effectiveness of secured data storage, the use of hashes of network data stored in each node, and low energy consumption of Fabric leading to high performanc
Participation in mass dog vaccination campaigns in Tanzania: Benefits of community engagement
Get PDFThis research article was published in the Frontiers in Public Health, 2022Background: Canine rabies causes about 59,000 human deaths each year globally but the disease can be eliminated by sustaining sufficient dog vaccination coverage over several consecutive years. A challenge to achieving high coverage is low participation of dog owners in vaccination campaigns. We explored whether and how previously identified contributory factors to low participation can be addressed through community engagement activities.
Methods: We engaged communities in two wards in Tanzania on dog behavior and handling, safe ways of interacting with dogs, and their perceptions of dog vaccination. We shared and elicited information from them through village meetings, video screenings, posters and leaflets and involved the leadership of one of the wards in planning and implementing a dog vaccination exercise to explore the feasibility of their participation. We assessed the impact of engagement activities with household surveys, meeting reports, observations and focus group discussions. We used a generalized linear mixed-effects model to identify predictors of knowledge and perceptions and compared knowledge amongst respondents before and after engagement activities. Qualitative data was analyzed inductively to explore perceptions of dog handling and vaccination and feasibility, opportunities and barriers to community leadership participation in organizing mass dog vaccination.
Main findings: Knowledge of dog behavior, dog handling, and safe ways of interacting with dogs was positively associated with age (p < 0.0001), dog ownership (p = 0.0203), training (p = 0.0010) and previous experience of a dog bite (p = 0.0002); and was negatively associated with being afraid of dogs (p = 0.0061) and participation in a recent dog vaccination campaign (p = 0.0077). Knowledge was low before and significantly improved after engagement activities. The majority (92%) of respondents believed dog vaccination has no negative effects on dogs. Respondents perceived lack of bonding with their dog as a limitation to the ability to restrain a dog for vaccination. The community performed most roles assigned to them in the dog vaccination exercise, but barriers such as lack of motivation for volunteering exist.
Conclusion: Engaging communities regularly on dog vaccination can improve their knowledge of dog behavior and dog handling techniques, and may help improve owner participation in dog vaccination campaigns
Improving biological treatment of textile wastewater
Get PDFThis research article was published by Water Practice & Technology Journal, Volume 17, Issue 1, 2022.Textile industries are among the primary contributors of water pollution. Treatment of textile wastewater is very important before discharging it to the environment. In the present study, laboratory-scale anaerobic batch reactors were used for co-treatment of a mixture of textile and domestic wastewater at 37 °C. The objective of this work was to investigate optimum conditions for the anaerobic co-digestion of textile wastewater and domestic wastewater. Domestic wastewater as a carbon source to enhance treatment of textile wastewater in color and other pollutants removal was examined. Textile and domestic wastewater were mixed at different proportions to make a total volume of 500 mL. Proportions of domestic wastewater and retention time were two main factors studied in influencing pollutant removal efficiency. Optimum conditions for removal of pollutants were 18 days' residence time at 60 and 40% textile and domestic wastewater respectively. The removal efficiencies were 52.8, 58.3 and 51.6% for Color, BOD and COD, respectively. Phosphorus (PO43−), Ammonium (NH3-N) and Nitrate (NO3-) increased at 78.5, 49 and 87% respectively. However, the concentration levels were above Tanzania Bureau of Standards (TBS) discharge limits. Post treatment is suggested to achieve standard discharge limits