Browsing by Author "Ngondya, Issakwisa"

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Can Cynodon dactylon Suppress the Growth and Development of the Invasive Weeds Tagetes minuta and Gutenbergia cordifolia?
(MDPI, 2019-12-06) Ngondya, Issakwisa; Treydte, Anna; Ndakidemi, Patrick; Munishi, Linus
Approaches to managing invasive plants is challenging, particularly in protected areas where conventional methods, such as chemical herbicide applications are limited. We studied the effects of varying densities of Cynodon dactylon on the growth and development of the invasive weeds Tagetes minuta and Gutenbergia cordifolia in northern Tanzania. We conducted pot and field plot experiments following a completely randomized block design that was replicated three times. Increasing densities of C. dactylon significantly reduced growth, leaf total chlorophyll, biomass and significantly increased leaf anthocyanin of both T. minuta and G. cordifolia invasives. Our results further showed that the critical density of C. dactylon to suppress the two invasive species is ≥ 8 plants/m2. We suggest that C. dactylon can successfully be used as an alternative eco-friendly and sustainable approach for managing invasive weeds, such as T. minuta and G. cordifolia. This management technique can additionally improve forage production and biomass for wild and domestic herbivores in the affected areas.
Comparison of the effects of a broad-spectrum herbicide and a bio-herbicide on insect flower visitation in the Serengeti ecosystem, Tanzania
(Elsevier, 2021-12) Mbundi, Mecklina; Ngondya, Issakwisa; Ghaui, Mark; Treydte, Anna
The functional role of insect visitors on flowering plants is crucial to both natural and agricultural ecosystems. While, few studies have addressed the impact of invasive plant species on insect visitors, even less is known about how management practices against invasive plants may affect plant-pollinator interactions. We assessed how natural versus chemical-based management against the invasive plant Gutenbergia cordifolia affected insect visitors in Mwiba area, Tanzania. We compared the number of insect visitors, diversity and richness, the number of inflorescences visited, inflorescences abundance and flower diversity across treatments of Desmodium uncinatum crude leaves extract (DUL), the chemical glyphosate (GLY), and none /control (CON). We found that more than half (55%) of the insect visitors observed were found visiting flowering plants in DUL plots, followed by CON with 26% and GLY plots with 19%. Further, DUL plots had almost twice as many inflorescences visited compared to CON and GLY plots. Inflorescence’s abundance and flower diversity were significantly higher in DUL plots compared to CON and GLY plots. Our study revealed that DUL treatment did not disrupt insect flower visitation but rather attracted more insects. We conclude that using the natural plant extract treatment is highly preferable to the chemical management of invasive plants such as G. cordifolia, as the DUL treatment maintained and even enhanced flower diversity while suppressing G. cordifolia and fostering insect visitors.
Conservation and Management Challenges Facing a Medicinal Plant Zanthoxylum chalybeum in Simanjiro Area, Northern Tanzania
(MDPI, 2020-05-19) Mbinile, Scholastica; Munishi, Linus; Ngondya, Issakwisa; Ngondya, Issakwisa; Ndakidemi, Patrick
The information on the medicinal use, availability, challenges, and future conservation strategies for the medicinal plant Zanthoxylum chalybeum were gathered by using a semi-structured questionnaire, focused group discussions, and field observations in Simanjiro Area, Tanzania. Data were collected from local village members who were familiar with the tree and the key informants. Data were analyzed using Statistical Package for the Social Sciences (SPSS). The extent of use was found to be very high, with more than three-quarters of harvested parts used for treating women’s health system (86.4%). The most used plant parts for medicinal purposes were reported to be the roots and the stem bark (90.3% and 81.6%, respectively), possibly suggesting mortality caused by heavy harvesting. In addition to unsustainable harvesting methods, minimal and unpredictable propagation methods were the key factors affecting the recruitment rate, with perhaps an addition of continued climate and land-use change (93.2%), indicative of low precipitation and high agriculture and settlement expansions. Given these challenges, the future conservation and persistence of Z. chalybeum looks uncertain, which requires such measures as the provision of education and awareness and ensuring proper land-use plans that encompass active recruitment of the species in these areas.
Conservation and Management Challenges Facing a Medicinal Plant Zanthoxylum chalybeum in Simanjiro Area, Northern Tanzania
(MDPI, 2020-05-19) Mbinile, Scholastica; Munishi, Linus; Ngondya, Issakwisa; Ndakidemi, Patrick
The information on the medicinal use, availability, challenges, and future conservation strategies for the medicinal plant Zanthoxylum chalybeum were gathered by using a semi-structured questionnaire, focused group discussions, and field observations in Simanjiro Area, Tanzania. Data were collected from local village members who were familiar with the tree and the key informants. Data were analyzed using Statistical Package for the Social Sciences (SPSS). The extent of use was found to be very high, with more than three-quarters of harvested parts used for treating women’s health system (86.4%). The most used plant parts for medicinal purposes were reported to be the roots and the stem bark (90.3% and 81.6%, respectively), possibly suggesting mortality caused by heavy harvesting. In addition to unsustainable harvesting methods, minimal and unpredictable propagation methods were the key factors affecting the recruitment rate, with perhaps an addition of continued climate and land-use change (93.2%), indicative of low precipitation and high agriculture and settlement expansions. Given these challenges, the future conservation and persistence of Z. chalybeum looks uncertain, which requires such measures as the provision of education and awareness and ensuring proper land-use plans that encompass active recruitment of the species in these areas
Demonstrative effects of crude extracts of Desmodium spp. to fight against the invasive weed species Tagetes minuta
(Elsevier, 2016) Ngondya, Issakwisa; Munishi, Linus; Treydte, Anna; Ndakidemi, Patrick
Threats on native flora and fauna by invasive plant species represent one of the main conservation and management challenges in rangelands. Methods that are both effective and ecologically safe to suppress invasives are urgently needed but have rarely been used, thus, highlighting the need to devise and test ones. In our study, we used a completely randomized design to assess the allelopathic effects of Desmodium uncinatum and Desmodium intortum leaf (DuL, DiL respectively) and root (DuR, DiR respectively) extracts on germination and seedling vigor of the invasive weed Tagetes minuta.We also assessed seedling germination, height, fresh weight and chlorophyll content after fourteen days and thirty days of treatment separately. The mean percentage germination per treatment in and across each group differed significantly (P b 0.05), with DuL having the highest suppressive effect (P = 0.003). Likewise, the mean germination per treatment was more strongly negatively correlated with treatment concentration in DuL treatments in both laboratory and screen house experiments (r = −0.48, P = 0.0003 and r = −0.91, P b 0.0001 respectively) than in DuR, DiL and DiR. Seedling height, fresh weight and chlorophyll content (Chl) differed significantly (P b 0.05) between the four treatment groups. Seedlings treated with higher concentrations were observed to be shorter, having lower fresh weights and Chl content than those treated with lower concentrations. The DuL higher concentration showed a trend of shorter seedlings with lower fresh weights and Chl content than other groups. Our findings suggest that D. uncinatum may probably be used to control invasive species, T. minuta and should be integrated into the management practices in the affected areas. Also our data suggest that a potential exists in devising an innovation that is both ecologically safe and effective by using Desmodium spp. making it possible to improve rangelands production through planting them in the areas affected by invasive species.
The effect of Helichrysum shrub encroachment on orchids in a tropical, montane grassland ecosystem, Tanzania
(CSIRO PUBLISHING, 2024-11-08) Mgimba, Christopher; Ngondya, Issakwisa; Treydte, Anna
Context Although shrub encroachment is a common phenomenon in grasslands, which often suppress co-existing herbaceous plants, little is known about how encroaching native shrubs affect endemic and threatened orchid species. Aims We assessed the effect of the native dwarf shrub Helichrysum species on orchid species in a protected mountainous grassland system in Tanzania. Methods We selected five Helichrysum shrub-dominated blocks and applied four treatments in each, i.e. no or low encroachment (<20% Helichrysum cover; ‘low cover’), high encroachment (>50% Helichrysum cover; ‘high cover’), cutting all stems of Helichrysum shrubs to ground level (‘stem cut’) and removing both stems and roots of all Helichrysum shrubs (‘uprooted’). We then compared orchid species diversity, abundance and functional traits by using a mixed linear model across treatments. Key results Orchid species diversity and abundance were significantly lower in ‘high cover’ plots than in other treatments. In ‘high cover’ plots, orchid species such as Disa robusta, Satyrium acutirostrum, and S. sphaeranthum had a significantly lower chlorophyll content than they did in ‘low cover’ plots. The ‘uprooting’ treatment showed significantly higher orchid species diversity in the second field season. Conclusion The expansion of Helichrysum shrubs adversely affected orchid abundance, diversity, and individual vigour, which in turn affected the regenerative ability of orchids. Implications We suggest that management should focus on shrub removal, because only ‘cutting’ had a beneficial effect on orchids. Shrub removal should be focused on areas of high shrub cover to promote further orchid species growth in this mountainous grassland of Tanzania.
The effects of extreme climate on the invasive plant Gutenbergia cordifolia: implications for its future management in savannah ecosystems
(Heliyon, 2022) Nyarobi, Herieth; Ngondya, Issakwisa; Munishi, Linus
The aim of this study was to assess the effects of varying water stress levels on morphological and physiological parameters of an invasive plant Gutenbergia cordifolia. The assessment was conducted in the screenhouse at the Nelson Mandela African Institution of Science and Technology following a completely randomized design (CRD). Both morphological and physiological parameters were variable under water stress levels. While the maximum (159 cm) and minimum (9 cm) plant heights for G. cordifolia were observed under flood and drought water stress respectively, its maximum root collar diameter of 5 mm and the minimum of 1.3 mm were observed under moderate flood and drought water stress respectively. Generally, the number of leaves was highest under mod erate flood stress (194 leaves/plant), and lowest under drought stress (13 leaves/plant). Similarly, the largest and smallest leaf surface area of 9 103 and 1 103 mm2 were observed under flood and drought water stress respectively due to G. cordifolia's tendency to retain water when exposed to water stress through a reduction in number of leaves and leaf surface area when under drought stress condition. While a decrease in leaf chlorophyll was observed across water stress levels with the lowest chlorophyll levels of 0.02 under drought water stress, an increase in leaf anthocyanin levels (0.29 Abs g.DM 1 ) was observed particularly under flood stress due to increased chlorophyll breakdown and plants' water stress, respectively. This study informs that extreme climatic events such as excessive floods will likely facilitate invasions by G. cordifolia leading to decreased biotic resistance of native communities in savanna rangelands. Efforts to manage G. cordifolia's effects in a changing climate must therefore include the development of strategies and action plans that account for catastrophic events like floods and drought.
Environmental factors and non-chemical methods to suppress growth of the invasive plant Gutenbergia cordifolia
(Elsevier, 2023-08-01) Mero, Sarah; Ngondya, Issakwisa; Treydte, Anna
Little is known about preferred environmental conditions and non-chemical control of invasive Gutenbergia cordifolia. We assessed the effects of different A. annua crude extract concentrations, synthetic herbicide (glyphosate), fire regime and shade to G. cordifolia germination, shoot and root dry biomass, seedling height and leaf chlorophyll. High concentrations (75%) of A. annua crude extracts significantly reduced germination percentage of G. cordifolia by 25% (F2,4=77.2, p < 0.001), and suppressed shoot and root dry biomass (F2,4 = 80.3, p < 0.001; F2,4=46.104, p < 0.001, respectively) as well as seedling height and leaf chlorophyll (F2,4 = 12.02, p < 0.002; F2,4 = 15.9, p < 0.001), respectively. Medium temperature (60 °C) and long exposure time (5 min) significantly increased G. cordifolia germination percentage (F2,7 = 32.6, p < 0.001) while extreme temperatures (≥150 °C) at both (1 min) short and (5 min) long exposure time completely suppressed germination of G. cordifolia. Under high shade, while germination percentage was a third that of other treatments (F 2, 4 = 20.9, p = 0.008), mean germination took twice as long (F2, 4 = 17.9, p = 0.010) and shoot fresh biomass was reduced by half (F 2, 4 = 16.92, p = 0.004). Shoot and root dry biomass were reduced to more than a third under high shade, seedling height reduced to half but leaf chlorophyll content was not affected (F 2,4 = 6.3, p = 0.030; F 2,4 = 9.1, p = 0.020; F 2,4 = 18.3, p = 0.003; F 2,4 = 3.02, p = 0.120, respectively). We suggest using A. annua as a potential bio-herbicide and highlight considering fire and shade as suppressor tools to control G. cordifolia, but first include in-situ trials to assess their impacts to both native plants and animals.
Harnessing traditional principles and guidelines for utilization compliance and sustainability of Maasai Alalili systems in northern Tanzania
(Taylor & Francis, 2025-05) Hezron, Elkana; Ngondya, Issakwisa; Munishi, Linus
Resilience in Indigenous communities and their lands faces challenges from multiple fronts, including climate change, biodiversity loss, altered biogeochemical flows, and socio-cultural transitions. Innovative solutions like Indigenous local knowledge featuring the community repositories that could enable policy practice are needed to explore, shift, and articulate such trajectories towards sustainable and desired futures. The study used a mixed-method approach to gather information on the extent to which Maasai communities practice traditional principles and guidelines for sustainable management of the Alalili systems. Purposive and stratified random sampling techniques facilitated data collection from literature review, direct field observation, key informant interviews, focused group discussions, and household surveys, which were analyzed using Chi-square and t-tests, narrative, and descriptive techniques. The findings indicate a variation between the traditional principles and guidelines reported from the surveyed literature and those recorded from the field survey. We found that the literature sparingly reported six aspects of the traditional principles and guidelines, whereas the field survey from the community comprehensively reported four harmonized aspects. More than 50% of the surveyed Alalili systems are currently not complying with documented management principles and guidelines from the literature and community traditions, thus increasing their proximity to the effects of degradation. We reveal that the probability of compliance is higher in the private Alalili category. We recommend their official recognition by policymakers and putting them into practice as a conservation initiative for supporting future rangeland sustainability and the pastoral communities’ livelihood development.
Impact of invasive alien plants Gutenbergia cordifolia and Tagetes minuta on native taxa in the Ngorongoro crater, Tanzania
(Elsevier, 2021-09) Ngondya, Issakwisa; Munishi, Linus
Understanding the ecological impacts of invasive plant species on the native communities and identifying native plant species that co-exist with invasive plants are important for planning the effective control and restoration of invaded rangelands. Systematic random sampling technique was applied to assess the effect of the two invasive plants (Gutenbergia cordifolia and Tagetes minuta) on native vascular plant species’ cover and diversity as well as identification of native grasses that co-exist well with the two invasive plants in the Ngorongoro crater, Tanzania. Native species ground cover in lowly invaded quadrats doubled that of medium and highly invaded quadrats. The mean height of native plants in highly invaded areas doubled the height of native plants in lowly invaded areas. While species richness was higher in both G. cordifolia and T. minuta lowly invaded quadrats compared to quadrats that were under medium and high invasion similarly, lowly invaded quadrats had higher species evenness than both medium and highly invaded quadrats. Cynodon dactylon was the most co-existing native grass with both G. cordifolia and T. minuta followed by Chloris pycnothrix. The results highlights how invasive plants G. cordifolia and T. minuta drastically changed the abundance and richness of the native vascular plant community within the Ngorongoro crater. It also highlighted on presence of native grasses that are capable of co-existing with the two invasive plants. This study further generated a baseline information for long term research to elucidate mechanisms associated with the two invasive plants interactions, while at the same time informing the management authorities on the threats to native plant species associated with invasive plants G. cordifolia and T. minuta.
The interplay between historical land-use and the distribution of Helichrysum shrubs in an African-protected grassland
(Wiley, 2024-05-01) Mgimba, Christopher; Smith, Stuart; Ngondya, Issakwisa; Treydte, Anna
Human land use can have lasting impacts on landscape characteristic, yet there remains a lack of information on how former land use affects plant communities in protected African grasslands. In this study, we investigated how land uses prior to the creation of Kitulo National Park, Tanzania, shaped the presence and abundance of the native shrub, Helichrysum species. We evaluated both plant species composition and soil properties across the park by dividing our sample into three different zones of historical land use based on participatory mapping. We divided the park into three former land uses: (1) livestock grazed and cultivated; (2) grazed only and (3) wild grazing with limited human impact. We observed that former grazed cultivated land use had five times higher Helichrysum abundance than former ‘wild’ land use. Soil pH, magnesium and phosphorus levels varied significantly across zones of historical land use but not between sites with and without Helichrysum species. Helichrysum splendidum was more abundant in soils with low soil phosphorus and magnesium concentrations. Our study demonstrates that historic grazing and cropping land uses through changes in soil nutrient properties can explain current Helichrysum species spread in protected areas. As such, conservation management plans would benefit from integrating mapping of former land uses to target interventions for problematic encroaching shrubs.
Invasive plants: ecological effects, status, management challenges in Tanzania and the way forward
(Journal of Biodiversity and Environmental Sciences (JBES), 2017-03-31) Ngondya, Issakwisa; Treydte, Anna; Ndakidemi, Patrick; Munishi, Linus
Over decades invasive plants have been exerting negative pressure on native vascular plant’s and hence devastating the stability and productivity of the receiving ecosystem. These effects are usually irreversible if appropriate strategies cannot be taken immediately after invasion, resulting in high cost of managing them both in rangelands and farmlands. With time, these non-edible plant species will result in a decreased grazing or browsing area and can lead to local extinction of native plants and animals due to decreased food availability. Management of invasive weeds has been challenging over years as a result of increasingly failure of chemical control as a method due to evolution of resistant weeds, higher cost of using chemical herbicide and their effects on the environment. While traditional methods such as timely uprooting and cutting presents an alternative for sustainable invasive weeds management they have been associated with promotion of germination of undesired weeds due to soil disturbance. The fact that chemical and traditional methods for invasive weed management are increasing failing nature based invasive plants management approaches such as competitive facilitation of the native plants and the use of other plant species with allelopathic effects can be an alternative management approach. Recently, new weed control mechanisms such as biological control and Integrated Pest Management (IPM) have been recommended to complement both the traditional and chemical control methods for improved performance. Plant-plant competition and allelopathy therefore, as natural plant life phenomenon presents an opportunity for successful invasive weeds management.
Managing invasive plants through a nature-based approach in complex landscapes
(Elsevier Ltd., 2022-02-09) Ngondya, Issakwisa; Munishi, Linus
Invasive 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.
A nature‑based approach for managing the invasive weed species Gutenbergia cordifolia for sustainable rangeland management
(SpringerPlus, 2016-10-13) Ngondya, Issakwisa; Munishi, Linus; Treydte, Anna; Ndakidemi, Patrick
Background: The invasive weed species Gutenbergia cordifolia has been observed to suppress native plants and to dominate more than half of the entire crater floor (250 km2 ) in the Ngorongoro Conservation Area (NCA). As this species has been found to be toxic to ruminants it might strongly impact animal populations in this eco logically diverse ecosystem. Hence, a nature-based approach is urgently needed to manage its spread. We tested two Desmodium spp extracts applied to G. cordifolia and assessed the latter’s germination rate, height, fresh weight and leaf total chlorophyll content after 30 days in both laboratory and screen house experiments. Results: Seedling germination rate was halved by Desmodium uncinatum leaf extract (DuL), particularly under higher concentrations (≥75 %) rather than lower concentra tions (≤62.5 %). Likewise, in both laboratory and screen house experiments, germina tion rate under DuL treatments declined with increasing concentrations. Seedling height, fresh weight and leaf total chlorophyll content (Chl) were also most strongly affected by DuL treatments rather than D. uncinatum root extract, Desmodium intortum leaf extract or D. intortum root extract treatments. Generally, seedlings treated with higher DuL concentrations were half as tall, had one-third the weight and half the leaf Chl content compared to those treated with lower concentrations. Conclusion: Our study shows a novel technique that can be applied where G. cordifolia may be driving native flora and fauna to local extinction. Our data further suggest that this innovative approach is both ecologically safe and effective and that D. uncinatum can be sustainably used to manage invasive plants, and thus, to improve rangeland productivity
Realizing UN decade on ecosystem restoration through a nature-based approach: A case review of management of biological invasions in protected areas
(PLOS Sustainability and Transformation, 2022-08-18) Munishi, Linus; Ngondya, Issakwisa
As the influx of different invasive species and their spread to new areas increases, there is a need for a rigorous and relevant scientific evidence-based control and restoration (EBCR) approaches to inform practical decisions and policymaking. While evidence-based decision is gaining popularity in science and policy, its potential for transformative change especially in the management of invasive plant species remains unexplored. Control and restoration of areas invaded by invasive plant species in natural and protected ecosystems require such decisions. Here, we provide a framework to guide how EBCR can contribute to transformative change and we argue that upscaling existing EBCR practices in areas invaded by invasive plant species (especially in protected areas (PAs)) requires coalitions of interdisciplinary science, public, private, and civil society actors with a common goal. Since actors’ roles and stakeholder interactions are dynamic, to achieve durable impacts, the upscaling process must continually engage and involve actors, while maintaining a balance of incentives among them. Social and cultural dimensions of local communities as well as their indigenous and local knowledge need to be incorporated. Pathways to upscaling EBCR may involve leveraging adaptive governance, integrating successful initiatives and lessons into public policy and practices, or reinforcing governance and management-led change with private efforts. We identify general lessons from (complex) PAs for successful upscaling of EBCR and illustrate the components of our framework through a novel application of a nature-based approach (NbA) in PAs invaded by invasive plant species.
Reconstructing Historical Distribution of Large Mammals and their Habitat to Inform Rewilding and Restoration in Central Tanzania
(SAGE Publications Ltd, 2023-04-05) Athumani, Paulo; Munishi, Linus; Ngondya, Issakwisa
Backgroundand research aim:In the anthropogenic landscapes where historically wildlife existed, there can be a potential for rewilding to reverse extinction. However, there is limited literature providing approaches to achieve successful rewilding. The current study aimed at providing empirical based methodological procedures for successful rewilding of the University of Dodoma (UDOM) and nearby degraded landscape by assessing past and current vegetation and large mammal species’ occurrence. Methodology:The past occurrence of mega-herbivores and their habitat was assessed using systematic literature survey, past vegetation maps and key informant interviews. EBSCOhost database and Google Scholar search engine were used for literature searching. A survey was conducted at UDOM area which is one of the remaining habitat patches in central Tanzania to examine present plant diversity. Results:The baseline vegetation map of 1960 indicated that the study area was mainly Savanna woodland. Literature suggested that anthropogenic activities resulted into Land-Use Land-Cover Changes (LULCC) leading into wild animals’ extirpation leaving remnant populations in the surrounding protected areas. While the key informant interviews verified local loss of mega-herbivores, field data collected at UDOM campus in 2022 indicated the vegetation transformation to bushland dominated by Dichrostachys cinerea. The area’s past vegetation composition was 33% grasses, 29% herbs, 21% shrubs and 17% trees while the current was 18% grasses, 42% herbs, 30% shrubs and 10% trees. Conclusion:The study revealed that central Tanzania hosted spectacular large mammal populations that interacted with the savanna which has recently been transformed to bushland. However, observed evidence on past existence of large mammals and recent elephants’ sightings at UDOM area indicate great potential for rewilding. Implication for conservation:Reconstructing historical information of ecosystems is crucial for successful rewilding. Such information can guide conservation efforts aiming at reversing extinction and reestablishing connectivity of large herbivore population across ecosystems.
Roles of Maasai Alalili Systems in Sustainable Conservation of Fodder Species of East African Rangelands
(Elsevier, 2025-01-01) Hezron, Elkana; Ngondya, Issakwisa; Munishi, Linus
Alalili systems are among the indigenous rangeland management strategies that face pressures from unsustainable land use practices and impacts of climate change. We aimed to establish the vascular fodder plants' composition and abundance, compared with historical vegetation data to understand their evolution and trends to inform sustainable management of rangelands in northern Tanzania. The vegetation composition of the northern Tanzania rangelands surveyed before the 1980s was compared to empirical data from a vegetation survey of Alalili in 2022. A cross-sectional design using purposive and stratified random sampling techniques was applied during the field survey. The quadrat count method was used to estimate the composition and diversity of fodder taxa in Alalili systems. Secondary data from the northern Tanzania rangelands before the 1980s were collected through a systematic literature review. Key informant interviews, focused group discussions, and household surveys were used to gather information about the community's knowledge of historical quality changes in the rangelands. Our results indicate that, before the 1980s, the rangelands of northern Tanzania had relatively higher fodder species composition (127 woody and 119 herbaceous species) than the Alalili systems in 2022 (119 woody and 82 herbaceous species). Fodder species composition and diversity were relatively higher in communal than in private Alalili (t = 4.18, P < 0.001). At the same time, the species density was lower in communal than in private Alalili (t = -2.7272, P = 0.008). This work suggests that Alalili systems still hold substantial diverse fodder plants that most northern Tanzanian rangelands used to harbor before the 1980s. Therefore, they can be considered reservoirs of vital fodder species that can be used to restore degraded rangeland areas in northern Tanzania and elsewhere.
Seasons and bee foraging plant species strongly influence honey antimicrobial activity
(Elsevier, 2023-06) Rikohe, Isack; Mlozi, Stephano; Ngondya, Issakwisa
Honey has been used in human medicine since ancient times due to its antimicrobial properties. However, honey antimicrobial potential varies due to floral sources, geographical origins, and seasonality. The current study assessed the antimicrobial activity of honey and honeybees’ preferred plants namely, Acacia mellifera, Ocimum basilicum, Hoslundia opposita, Combretum schumannii, Grewia bicolor, Terminalia brownii, Cordia monoica from Same district in Northern Tanzania, during the short and long rain seasons of 2021/2022. The agar well diffusion method was employed for the antimicrobial assay, and the antimicrobial activity was evaluated by measuring inhibition zones. Significant differences were observed in antimicrobial activities among honey of different seasons (F = 28.5, p = <0.001) and plant extracts (F = 15.9, p < 0.001). Honey A and D that were harvested at the end of the short rain season were found with higher antimicrobial activities (10–19 mm inhibition) than that harvested at the end of the long rain season (10–15 mm inhibition), and the most susceptible microorganisms were Escherichia coli and Staphylococcus aureus. For the tested plant extracts, T. brownii, C. schumannii, and H. opposita showed higher antimicrobial activities (11.3–19 mm inhibition) against pathogenic microorganisms than other tested plants. There was a strong positive correlation in antimicrobial activities (r = 0.836, p = 0.078, r = 0.756, p = 0.139, and r = 0.732 p = 0.159) between honey harvested at the end of the short rain season with some plant extracts from plants blooming during the same season. The study highlighted the variation in antimicrobial activities among honey harvested in different rain seasons and that there is antimicrobial relation between honey and plants that are foraged by honeybees. Thus, the antimicrobial ability of the honey depends much on the plant species foraged by honeybees.
Soil erosion in East Africa: an interdisciplinary approach to realising pastoral land management change
(IOP Publishing Ltd, 2018-12-03) Blake, William; Rabinovich, Anna; Wynants, Maarten; Kelly, Claire; Nasseri, Mona; Ngondya, Issakwisa; Patrick, Aloyce; Mtei, Kelvin; Munishi, Linus; Boeckx, Pascal; Navas, Ana; Smith, Hugh; Gilvear, David; Wilson, Geoff; Roberts, Neil; Ndakidemi, Patrick
Implementation of socially acceptable and environmentally desirable solutions to soil erosion challenges is often limited by (1) fundamental gaps between the evidence bases of different disciplines and (2) an implementation gap between science-based recommendations, policy makers and practitioners.Wepresent an integrated, interdisciplinary approach to support co-design of land management policy tailored to the needs of specific communities and places in degraded pastoral land in the East African Rift System. In a northern Tanzanian case study site, hydrological and sedimentary evidence shows that, over the past two decades, severe drought and increased livestock have reduced grass cover, leading to surface crusting, loss of soil aggregate stability, and lower infiltration capacity. Infiltration excess overland flow has driven (a) sheet wash erosion, (b) incision along convergence pathways and livestock tracks, and (c) gully development, leading to increased hydrological connectivity. Stakeholder interviews in associated sedenterising Maasai communities identified significant barriers to adoption of soil conservation measures, despite local awareness of problems. Barriers were rooted in specific pathways of vulnerability, such as a strong cattle-based cultural identity, weak governance structures, and a lack of resources and motivation for community action to protect shared land. At the same time, opportunities for overcoming such barriers exist, through openness to change and appetite for education and participatory decision-making. Guided by specialist knowledge from natural and social sciences, we used a participatory approach that enabled practitioners to start co-designing potential solutions, increasing their sense of efficacy and willingness to change practice. This approach, tested in East Africa, provides a valuable conceptual model around which other soil erosion challenges in the Global South might be addressed.
Spatial distribution and anthropogenic threats facing medicinal plant Zanthoxylum chalybeum in Simanjiro Area, Northern Tanzania.
(Elsevier, 2020-11) Mbinile, Scholastica; Munishi, Linus; Ngondya, Issakwisa; Ndakidemi, Patrick
Knob wood (Zanthoxylum chalybeum - Rutaceae) is a medicinal plant species subject to heavy exploitation throughout its areas of occurrence in Sub-Saharan Africa. Despite that the tree has different values as a traditional herb, there is a gap in understanding its current distribution and anthropogenic threats in its range areas. This study aimed at mapping the distribution and anthropogenic threats facing Z. chalybeum tree in different land uses of Simanjiro area, northern Tanzania. The rates of threats such as debarking, branch cutting, uprooting and harvesting were observed to be high in grazing lands (GL) and farmlands (FL) (73% and 62% respectively) while least threats were observed in game controlled areas (GCA) and game open areas (OA) (39% and 40% respectively). Majority of trees observed had signs of debarking (51%) followed by debarking and branch cutting (20.6%), debarking and uprooting, (15.8%), debarking, branch cutting and uprooting (4.76%), whole tree cutting (4.76%) and branch cutting (3.17%). Conservation areas (i.e. hunting blocks within game controlled areas and game open areas) were found to have higher abundance of Z. chalybeum with detectable distribution pattern than other locations in Simanjiro area. The current observation in this study also shows that the rates of harvesting are increasing and harvesting methods used by community members are unsustainable. Regulatory approaches that promote sustainable harvesting of the species should be developed and implemented to reduce the impacts of over harvesting of the species on its population persistence. Promotion of cultivation and conservation of the species in farmland would help reduce the harvesting pressures in protected areas while providing access by the local community in their farms.