MUST Repository :: Browsing by Author "Ojija, Fredrick"

Browsing by Author "Ojija, Fredrick"

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A Preliminary Study on Abundance and Diversity of Aquatic Macro Invertebrates of Nzovwe Stream, in Mbeya, Tanzania
(Research Publish Journals, 2016) Ojija, Fredrick; Kavishe, Regan
The purpose of this current study was to determine the diversity, species richness, dominance and evenness of macroinvertebrates fauna found in Nzovwe stream. The study was carried out from 02 November to 28 December 2015. A total of 584 aquatic macroinvertebrate from 7 orders and 16 species were recoded. They belonged to 22 families. This study shows that Odonata (35.96%) was the most dominant order according to total number of individuals, followed by Hemiptera (25.514%), Coleoptera (19.007 %), Diptera (12.842%), Plecoptera (5.137%), Gastropoda (1.027%) and Ephemeroptera (1.027%). The most abundant species were Dragonflies (27.226%), Water striders (13.185%), and Creeping water bugs (10.274%), whereas the least abundant species were Giant water bugs and Backswimmers (0.514%). The Shannon-Wiener Index diversity and Evenness index (Pielou’s index) was higher in order Coleoptera (1.33) and Diptera (0.940) respectively. Ephemeroptera, Plecoptera and Gastropoda (Shannon’s, H’ = 0.00) were the lowest. Simpson’s Reciprocal Index diversity was highest in order Coleoptera (3.400) while Ephemeroptera, Plecoptera and Gastropoda (1/D = 1.000) were the lowest. The species richness of macroinvertebrates was calculated by using Margalef’s Index. Moreover, it was found that the stream is poorly managed and threatened by pollution from domestic wastes.
Allelopathic Effects of Sphaeranthus Suaveolens (Forssk.) DC. and Argemone Mexicana L Leaf Crude Extract On Zea Mays L Germination and Growth
(ResearchGate, 2023) Ojija, Fredrick
Sphaeranthus suaveolens (Forssk.) DC. and Argemone mexicana L. plant species are agricultural weeds that threaten crops and native plant diversity in East Africa, particularly in Tanzania. Yet, there have been few studies to assess whether their allelopathic effects inhibit plant germination and growth. Experiments were carried out in petri dishes and pots to investigate the inhibition effects (here referred to as negative allelopathy) of S. suaveolens leaf (SsL) and A. mexicana leaf (AmL) crude extracts on Zea mays L germination and seedling growth. Zea mays seeds and seedlings were treated with different crude concentrations of SsL and AmL to investigate their inhibition potential. The results showed that SsL and AmL crude extract concentrations delayed and/or reduced Z. mays germination, particularly at higher concentrations (70% and 100%). At these higher concentrations, few seeds germinated compared to the number of seeds germinated at lower concentrations (0%, 25%, and 50%). Further, it was found that Z. mays growth vigour was negatively affected as evinced by lower stem and root lengths, diameters, and total fresh biomass at higher concentrations of SsL and AmL. Although this study demonstrates the allelopathic effect of S. suaveolens and A. mexicana on Z. mays germination and growth, it also recommends further laboratory and field research experiments to investigate their allelopathic effects on other crops and native plants. However, this study advises that the management and control of these weeds be taken into account as their inhibitory effects could subsequently lead to a loss of plant diversity and crop productivity.
An Invasive Plant Parthenium Hysterophorus Reduces Native Forage Cover
(East African Journal of Environment and Natural Resources, 2022) Ojija, Fredrick; Lutambi, Leticia P
While some research has been conducted in sub–Saharan Africa on the alien invasive Parthenium hysterophorus, little work has assessed whether it is poses negative impact on native forages. A field survey was carried out to study the dominant co–existing plant species, and its impact on plant abundance, species, and native forage cover. We found that non–natives were the dominant co–existing plants with P. hysterophorus compared to natives. Plant species (r = -0.889, P = 0.043) and abundance (r = -0.968, P = 0.007) decreased with increasing invasive percent cover. Moreover, native forage plant (Brachiaria reptans; r = -0.922, P = 0.026), Cynodon dactylon; r = -0.972, P = 0.006, Digitaria milanjiana; r = -0.938, P = 0.018, and Indigofera spicata; r = -0.977, P = 0.004) percent cover decreased with increasing invasive percent cover. The study concludes that P. hysterophorus negatively affects plant diversity, and thus, should controlled.
Analysis of Qater Quality Parameters and Ecosystem Services of Nzovwe Stream
(IJBLST, 2015) Ojija, Fredrick
This paper presents analyzed physico-chemical parameters and assessed ecosystem services of Nzovwe stream. Physico-chemical parameters were analyzed using methods and procedures as prescribed by American Public Health Association and Tanzania Bureau of Standards. Whereas, ecosystem services were assessed qualitatively using households survey questionnaires. In average the water sample from Nzovwe stream had the following measurement; pH was 8.14(±07SD), Temperature 24.7(±0.2SD)0C, Turbidity 320(±20SD)NTU, Total alkalinity 202(±2SD)mg/L, Total hardness 58(±8SD)mg/L, Electrical conductivity 540(±20SD)μs/cm, Total suspended solids 314.027(±73.19SD)mg/L and Total dissolved solids 361.8(±13.4SD)mg/L. Field observations revealed that the stream is in danger of being polluted due to human activities (i.e. washing clothes and bathing, cultivation or gardening, irrigations) and dumping of wastes from households. Physico-chemical parameters showed no or little evidence of a stream being polluted because almost all parameters were within permissible range of Tanzania Bureau of standards (TBS). About 90% of interviewed households said that Nzovwe stream supply them with provisioning services (fresh water for drinking, washing, bathing, or sanitation purposes and other domestic uses); 3% said that they extract building materials (soil and pebbles); 5% specified that they use stream water for irrigation of crops (banana trees, maize) and gardens (vegetables); while 2% obtain pastures to feed livestock. This study recommends that future studies must include biological parameters instead of using only physico-chemical parameters to assess the quality of water in Nzovwe stream. Moreover, local authority must ensure that the stream is well protected by establishing stream management committees which will incorporate individuals from households adjacent the Nzovwe stream.
ARGEMONE MEXICANA’S LEAF CRUDE EXTRACT SUPPRESSES PHASEOLUS VULGARIS AND ZEA MAYS GERMINATION AND GROWTH
(Tropical Agroecosystems, 2023) Ojija, Fredrick
The Argemone mexicana plant species is invading many habitats in Tanzania. Nevertheless, there have not been many studies to assess how it affects crops. In petri dishes and pot experiments, we investigated the suppressive effects of A. mexicana on Phaseolus vulgaris and Zea mays germination and seedling growth. Different concentrations of A. mexicana leaf (AmL) crude extract was applied to the seeds and seedlings of P. vulgaris and Z. mays. At higher concentrations (>70%), AmL crude extract concentrations reduced the germination and growth of P. vulgaris and Z. mays seeds. The fresh biomass, root lengths, stem diameters, and heights of P. vulgaris seedlings were reduced at higher concentrations (>75%) of AmL, which had a negative impact on their growth vigour. Although this study shows that P. vulgaris and Z. mays germination and growth were inhibited by A. mexicana crude extract, field research experiments should investigate the suppressive effects of this invasive weed on native plant species. The study recommends further management of A. mexicana to protect native biodiversity. It is expected that these results will be helpful in developing policies and programs for managing invasive plants while taking into account the effects on people's livelihoods.
Awareness, Habitats and Population Status of the Endangered Rungwecebus kipunji in Mt. Rungwe Nature Reserve, Tanzania
(MUST Journal of Research and Development, 2022) Ojija, Fredrick; Maijo, Simula P.; Mwidege, Asheri
The Mount Rungwe Nature Reserve in Tanzania is a significant ecological area that protects the endangered Rungwecebus kipunji. The goal of the study was to analyze the ecological habitat and population of R. kipunji in Mount Rungwe Nature Reserve. During our study, we recorded 412 (mean: 41.2 ± S.E: 5.7) R. kipunji individuals in the reserve. The R. kipunji population was found in a comparatively low abundance at sites with a significant number of anthropogenic activities. Human activities were observed to occur less frequently (χ2 = 40.76, p = 0.0001) inside the nature reserve (n = 33, 17.19%) than outside and/or along the border zones (n = 159, 82.81%). Respectively, the peeling of tree bark and firewood collection were the most common anthropogenic indicators found inside and outside the forest reserve. We also found that >40% of male and > 30% of female respondents were aware of R. kipunji’s presence. We found that 30% of female and 32% of male respondents had previously received conservation education. In comparison to other age groups, >25% of respondents aged > 45 years old claimed to have already learned about R. kipunji. Furthermore, 48% of the respondents claimed that Mount Rungwe Nature Reserve helps them live by providing fuelwood and building materials. People aged 31–43 and > 43 years old collect fuelwood and building materials, respectively, while those under 31 years old collect food resources. In summary, our findings imply that, to improve R. kipunji, local residents surrounding the forest reserve should be made aware of the species to reduce anthropogenic activities within and along the reserve's buffer zones. Thus, our findings suggest that the R. kipunji populations and habitat quality in Mount Rungwe Nature Reserve could be used as a benchmark for the conservation of other endangered species elsewhere.
Biodiversity conservation and construction industry: Impacts, regulatory frameworks, and challenges
(CAB International, 2025-05-07) Ojija, Fredrick; Lutambi, Leticia P.; Mng’ong’o, Marco E; Mtui, Godliving Y.S; Katambara, Zacharia S
The construction industry plays a crucial role not only in economic development but also presents significant challenges to environmental sustainability. Construction activities frequently result in habitat destruction, pollution, land degradation, fragmentation, and the spread of invasive species, all of which pose severe threats to ecosystems and biodiversity. These impacts contribute to climate change, accelerate biodiversity loss, and endanger vulnerable species and habitats. Without proper mitigation strategies, construction projects can lead to irreversible ecological damage. However, integrating biodiversity-friendly practices into construction planning and execution can help minimize negative effects and enhance ecosystem resilience. A balanced approach that incorporates biodiversity conservation into development processes is essential for achieving sustainable development goals. To address these challenges, regulatory frameworks and environmental policies have been established to prevent or mitigate biodiversity loss caused by construction activities. However, the effectiveness of these regulations varies across regions, often due to gaps in enforcement, inadequate ecological assessments, and insufficient stakeholder engagement. This review critically examines the existing regulatory frameworks governing construction-related biodiversity impacts, assessing their strengths and weaknesses. It identifies areas where policy improvements and stricter enforcement are needed to enhance environmental protection. Furthermore, this study explores sustainable construction practices that can minimize ecological harm, such as green infrastructure, habitat restoration, and nature-based solutions. It also highlights the challenges of aligning rapid urbanization and infrastructure development with biodiversity conservation, including conflicting interests between economic growth and environmental protection. By analysing these challenges and opportunities, this review provides insights into how sustainable construction practices and well-implemented regulations can contribute to biodiversity conservation. Strengthening legal frameworks, fostering cross-sector collaboration, and incorporating scientific research into decision making processes will be key to balancing construction development with ecological sustainability. A proactive approach is essential to ensure that future construction projects support both economic progress and environmental integrity.
Cerebral Death: Unraveling the Mystery of the Silent Mind
(MJRD, 2024-12-05) Akram, Muhammad; Ojija, Fredrick; Suke, Mary Nicholaus
The permanent loss of all brain stem functions, such as breathing, awareness, and cranial nerve reflexes, is known as brain stem death (BSD), and it presents a significant medical and ethical issue. While other bodily functions, such as heart activity and circulation, can be maintained with medical intervention, BSD is defined by the cessation of brain stem activity. The key characteristic that distinguishes BSD from other conditions, such as coma or a persistent vegetative state, is the complete and irreversible loss of brain stem function—a critical control centre for basic physiological processes. Diagnosing BSD requires strict clinical criteria and diagnostic testing to confirm the full and permanent nature of the condition. This typically involves a comprehensive neurological examination, assessment of cranial nerve reflexes, and confirmation through additional tests, such as cerebral blood flow studies or electroencephalography (EEG). A diagnosis of BSD carries significant ethical and legal implications, particularly in relation to organ donation, as it often plays a role in identifying potential donors. The ethical considerations surrounding BSD include its impact on families, the distinction between death and end-of-life care, and the challenges posed by varying legal and cultural perspectives. It highlights the importance of a clear diagnosis, obtaining informed consent, and adhering to established medical protocols to uphold human dignity and ethical standards. As medical technology advances and societal views evolve, the discussion around brain stem death continues to be a critical issue in both bioethics and modern medical practice.
Community Structure, Conservation Status, and Functional Groups of Bird Species in Mbeya Range Forests, Tanzania
(Science Education Technology, 2022-03-07) Ojija, Fredrick; Manyanza, Ndaki M.
The Mbeya range forest reserves (MRFRs) of the southern highland of Tanzania are an important hotspot for biodiversity conservation. However, its avian biodiversity has hardly ever been studied. Thus, for the first time, this study presents the inventory of bird species from MRFRs, demonstrating community structure, functional group, and conservation status. The study was carried out in four forest areas (i.e., Idugumbi, Kawetire, Mount Loleza, and Muvwa) within the MRFRs. The bird survey was carried out monthly between March 2018 and June 2018. Standardised line and point counts, as well as mist netting, were used to collect data. A total of 1052 individual birds, representing 41 species and 22 families, were recorded. Relative abundance, Shannon and Simpson species diversity, and species richness were high in Idugumbi forest and lowest in Kawetire forest. Species diversity differed significantly between the four forest areas. Moreover, Idugumbi and Muvwa had relatively low species composition dissimilarity compared to other forest areas. Different bird functional groups, i.e., insectivores, granivores, nectarivores, carnivores, frugivores, or combinations of these, were recorded in MRFRs. The insectivores were twice as abundant as granivores and nectarivores. The multi–layered vegetation structure of native plants in the Idugumbi forest appears to benefit and contribute to bird communities. The study reveals that MRFRs are an important hotspot for bird species that require ecological monitoring and protection. As a result, appropriate land–use practices near MRFRs should be followed to ensure long–term avian conservation
Diversity and Abundance of Arthropods at Mbeya University of Science and Technology, Tanzania
(IJSTR, 2016-09-09) Ojija, Fredrick
Despite the high abundance of arthropods in many terrestrial environments, our understanding of their ecological diversity and abundance remain unknown in some habitats. The aim of this study is to assess the abundance, diversity and species richness of some arthropods found in grassland and woodland habitats at Mbeya University of Science and Technology in Tanzania. A total of 1719 arthropods belonging to 63 species under 12 orders and 46 families were collected. Parameters such as Shannon index, Simpson index, Margalef index, Evenness index and Sorenson similarity index were used to analyse the diversity of arthropods. Result showed that, Hymenoptera (33.101%), Coleoptera (28.098%) and Orthoptera (17.510%) were the most dominant orders, whereas the least abundant order were Diptera (0.814%) and Scolopendromorpha (0.291%). The grassland showed high species richness, Margalef index (D = 6.930), abundance (n = 1177), Evenness (E = 0.854) and Shannon diversity (H = 3.339) of arthropods. The abundance of arthropod groups between grassland and woodland differed significantly (p<0.05). Sorensen similarity index in both habitats showed 53.5% similarity. Therefore, result indicates that the grassland habitat has the potential to support arthropod diversity and act as effective refugia for some arthropods from woodland.
Diversity and Abundance of Arthropods at Mbeya University of Science and Technology, Tanzania.
(INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH, 2016-09-06) Ojija, Fredrick
Despite the high abundance of arthropods in many terrestrial environments, our understanding of their ecological diversity and abundance remain unknown in some habitats. The aim of this study is to assess the abundance, diversity and species richness of some arthropods found in grassland and woodland habitats at Mbeya University of Science and Technology in Tanzania. A total of 1719 arthropods belonging to 63 species under 12 orders and 46 families were collected. Parameters such as Shannon index, Simpson index, Margalef index, Evenness index and Sorenson similarity index were used to analyse the diversity of arthropods. Result showed that, Hymenoptera (33.101%), Coleoptera (28.098%) and Orthoptera (17.510%) were the most dominant orders, whereas the least abundant order were Diptera (0.814%) and Scolopendromorpha (0.291%). The grassland showed high species richness, Margalef index (D = 6.930), abundance (n = 1177), Evenness (E = 0.854) and Shannon diversity (H = 3.339) of arthropods. The abundance of arthropod groups between grassland and woodland differed significantly(p<0.05). Sorensen similarity index in both habitats showed 53.5% similarity. Therefore, result indicates that the grassland habitat has the potential to support arthropod diversity and act as effective refugia for some arthropods from woodland.
Dynamical Analysis of Mpox Disease with Environmental Effects
(MDPI, 2025-05-29) Helikumi, Mlyashimbi; Ojija, Fredrick; Mhlanga, Adquate
In this study, we develop a fractional-order mathematical model for investigating the transmission dynamics of monkeypox (Mpox), accounting for interactions between humans, rodents, and environmental reservoirs. The model uniquely integrates two key control strategies—public health awareness and environmental sanitation—often over- looked in previous models. We analyze the model’s well-posedness by establishing the existence, uniqueness, and positivity of solutions using the fixed-point theorem. Using data from the Democratic Republic of Congo, we estimate the model parameters and demon- strate that the fractional-order model (φ = 0.5) fits real-world data more accurately than its integer-order counterpart (φ = 1). The sensitivity analysis using partial rank correlation coefficients highlights the key drivers of disease spread. Numerical simulations reveal that the memory effects inherent in fractional derivatives significantly influence the epidemic’s trajectory. Importantly, our results show that increasing awareness (ε) and sanitation efforts (η) can substantially reduce transmission, with sustained suppression of Mpox when both parameters exceed 90%. These findings highlight the synergistic impact of behavioral and environmental interventions in controlling emerging zoonotic diseases.
Ecology and Influence of Age and Habitats on the Diurnal Activity Patterns of Cattle Egret (Bubulcus Ibis)
(INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH, 2025) Ojija, Fredrick
It was found that habitat types and age may influence diurnal activities of cattle egrets. In average, the grassland comprised 41.59% of all of diurnal activities, while forest and bushland comprised 21.54% and 35.79% of all of diurnal activities respectively (P0.05). The adult cattle egrets spent much time feeding than sub-adults and juveniles. The feeding behaviour was the diurnal activity of cattle egrets performed most often in the morning hours. The diurnal activity patterns and time budgets of the cattle egrets may be due to their strategies to cope with environmental factors such temperatures, different habitats and food availability; and high foraging behaviour can be due to high energy demand.
Effect of Global Climate Change on Insect Populations, Distribution, and its Dynamics
(ELSEVIER, 2025-07-07) Ojija, Fredrick; Mng’ong’o, Marco; Aloo, Becky N.; Mayengo, Gabriel; Helikumi, Mlyashimbi
Insects are vital to various ecosystems as pollinators, decomposers, and food sources for many organisms. They dominate diverse terrestrial (e.g., glassland) and aquatic (lakes, oceans, rivers, etc.) ecosystems. Previous studies report that more than half of the estimated 2.0 million species of living organisms identified on our planet are insects. However, global climate change (GCC), characterised by rising temperatures and altered precipitation patterns, significantly impacts their populations worldwide. We reviewed the literature to provide an overview of GCC events in insects. Collectively, the study findings reveal that global temperature and precipitation change are among the extreme GCC events affecting more than 30% of insect population, distribution, physiology, feeding habits, interactions, migration, and communication across the globe. The climate change intensifies insect cycles and insect damage in agroecosystems. In response, insect species alter their geographic ranges and phenology, changing population dynamics and interactions. GCC also influences reproductive patterns, including mating behaviour and breeding synchrony. Warmer global temperatures might advance or delay insect emer- gence, causing mismatches with food availability or pollination partners. While some insect populations may adapt, extreme heat events or prolonged droughts exceeding their physiological tolerance result in population declines or local extinctions. Predictions suggest that up to 65% of insect populations could face extinction within the next century due to increasing climate change. Thus, understanding these impacts is essential for predicting the ecological consequences of the GCC and developing effective conservation strategies to mitigate such impacts and protect insect biodiversity and ecosystem services
Emerging Environmental Contaminants: Sources, Effects on Biodiversity and Humans, Remediation, and Conservation Implications
(Sage, 2024) Ojija, Fredrick
Ecosystems, biodiversity, and the human population all depend on a quality or uncontaminated envir onment. Quality environment provides people and wildlife access to nutrition, medications, dietary sup plements, and other ecosystem services. The conservation of biodiversity—that is, species richness, abundance, heredities, and diversity—as well as the control of climate change are facilitated by such an uncontaminated environment. However, these advantages are jeopardized by newly emerging envir onmental chemical contaminants (EECCs) brought on by increased industrialization and urbanization. In developing countries, inadequate or poor environmental policies, infrastructure, and national standards concerning the usage, recycling, remediation, control, and management of EECCs hasten their effects. EECCs in these countries negatively affect biodiversity, ecological services and functions, and human health. This review reveals that the most deprived or vulnerable local communities in developing coun tries are those residing near mining or industrial areas and cultivating their crops and vegetables on contaminated soils, as is wildlife that forages or drinks in EECC-contaminated water bodies. Yet, people in these countries have limited knowledge about EECCs, their threats to human well-being, ecosystem safety, and the environment, as well as remediation technologies. Besides, efforts to efficiently control, combat, regulate, and monitor EECCs are limited. Thus, the review aims to increase public knowledge concerning EECCs in developing countries and present a comprehensive overview of the current status of EECCs. It also explores the sources and advancements in remediation techniques and the threats of EECCs to humans, ecosystems, and biodiversity.
Energy Resources: Their Causal Relationship with Ecology and Environments.
(Asia Pacific Academy of Science Pte. Ltd., 2025-03-19) Lyanda, Romanus Peter; Ojija, Fredrick
Energy resources are critical drivers of economic development and societal progress, but their extraction, conversion, and use have profoundly impacted ecological systems and the environment. Therefore, it is essential to explore the relationships between energy resources and the environment throughout history. This paper examines the causal relationships between energy resource utilization and environmental changes, addressing both renewable and non-renewable energy sources. We analyze the environmental consequences of energy extraction and consumption, including pollution, habitat destruction, and climate change, and evaluate sustainable approaches to mitigate these effects. Fossil fuels have been the primary source of energy and are major contributors to greenhouse gas emissions, air and water pollution, and habitat destruction, all of which exacerbate global climate change. On the other hand, renewable energy sources such as wind, solar, and hydroelectric power are considered more sustainable. However, they also have environmental impacts, such as habitat disruption and high resource consumption. Researchers argue that trade-offs must be managed between increasing energy use, facilitated by technological advancements, and achieving sustainability. Energy generation and ecological goals should not be viewed as opposing or irreconcilable. With the implementation of appropriate policies, measures, and guidelines, energy production can be aligned with efforts to mitigate climate change and promote sustainability.
Exploring the Link Between Energy Resources and Global Biodiversity
(Asia Pacific Academy, 2025-02-28) Matwani, Joseph; Ojija, Fredrick
The availability of energy resources and their relationship with global biodiversity are critical concerns that demand urgent attention, especially given the world’s rising energy demands. This review paper examines the impacts of both renewable and non-renewable energy sources on biodiversity across different ecosystems. The extraction and use of fossil fuels—coal, oil, and natural gas—have led to severe pollution, habitat destruction, and climate change, threatening countless species and ecosystems. The processing and consumption of these non-renewable resources continue to accelerate biodiversity loss. While renewable energy sources—such as solar, wind, bioenergy, and hydropower—offer a pathway to reducing greenhouse gas emissions, they also pose biodiversity challenges. Large-scale solar farms alter land use, causing habitat fragmentation. Wind farms, while crucial for clean energy, threaten bird and bat populations. Hydropower projects disrupt river ecosystems, affecting aquatic species’ migration patterns. Similarly, bioenergy production often relies on extensive monoculture farming, leading to deforestation, agrobiodiversity loss, and competition with food crops. This paper explores mitigation strategies, emphasizing ecological offsets and habitat restoration as key conservation tools. These approaches align with global frameworks such as the United Nations Sustainable Development Goals (SDGs), ensuring that energy policies integrate biodiversity protection. The review highlights the importance of balancing energy expansion with environmental sustainability through strategic policymaking. A region- specific approach is essential, given the varying energy needs and ecological sensitivities across countries. Overreliance on energy-intensive technologies in some regions exacerbates environmental degradation, necessitating countermeasures to prevent resource overexploitation. By incorporating biodiversity-conscious energy strategies into decision- making, it is possible to achieve a sustainable balance between energy production and conservation. This analysis underscores the need for globally coordinated yet locally adaptive policies to ensure that the transition to renewable energy does not come at the expense of biodiversity.
Impact of Anthropogenic Habitat Changes on Insects: A Case Study of Mount Loleza Forest Reserve
(International Journal of Entomology Research, 2018-07-04) Leweri, Cecilia; Ojija, Fredrick
This study assessed the impact of anthropogenic activities on the abundance, diversity and composition of insect species on Mt. Loleza forest reserve in Mbeya, Tanzania. Insects were collected in disturbed, less disturbed and undisturbed habitats using pitfall traps, sweep nets and beating sheets. Data were analysed using one way analysis of variance (ANOVA) with Tukey's post hoc test and Kruskal Wallis. Shannon and Simpson diversities were compared using diversity t-test. Bray-Curtis similarity index was used to group families and species based on the number of individuals. In total, 3058 insect specimens belonging to 21 families and 40 species were collected. Insect abundance was highest in undisturbed habitats (50.10%). The Shannon diversity differed significantly between disturbed and undisturbed habitats (p < 0.05); and between less disturbed and undisturbed habitats (p < 0.05). Results of this study are vital toward effective conservation and management of the global insect species and other animals.
Invasive Argemone mexicana’s suppressive effects on Phaseolus vulgaris and Zea mays germination and growth
(bioRXiv, 2023) Ojija, Fredrick
Invasive Argemone mexicana plant species is invading many ecosystems in East Africa. However, there have not been many studies to assess how it affects plants. In petri dishes and pot experiments, we investigated the suppressive effects of A. mexicana on Phaseolus vulgaris and Zea mays germination and seedling growth. To investigate its suppressive effects on the test plant, different concentrations of A. mexicana leaf (AmL) crude extract were applied to the seeds and seedlings of P. vulgaris and Z. mays. At higher concentrations (70% and 100%), the findings showed that AmL crude extract concentrations reduced the germination and growth of P. vulgaris and Z. mays seeds. Compared to seeds that germinated at lower concentrations and in the control (0%) group, fewer seeds at higher concentrations grew. Accordingly, higher concentrations, relative to lower ones and controls, retarded seed germination. Additionally, the fresh biomass, root lengths, stem diameters, and heights of P. vulgaris seedlings were reduced under 75% and 100% AmL concentrations, which had a negative impact on their growth vigor. Although this study shows that P. vulgaris and Z. mays germination and growth were inhibited by A. mexicana crude extract, field research experiments are needed to investigate the suppressive effects of this invasive weed on other plant species. Due to its detrimental impact on plant growth, the study recommends further management of A. mexicana to protect biodiversity. It is expected that these results will be helpful in developing policies and programs for managing invasive plants while taking into account the effects on people’s livelihoods
Land-use/land-cover change in the Ngerengere River Catchment, Tanzania: Insights from 2004 to 2034
(ACCScience, 2025-07-21) Nkinda, Rose; Ojija, Fredrick
Land use and land cover (LULC) surrounding the Ngerengere River, Tanzania, which is a crucial water source, has led to a rapid decline in vegetated areas. Understanding these changes is vital for informed decision making and sustainable river catchment management. This study assessed historical LULC trends from 2004 to 2024, projected the current trend of change to 2034, and analyzed the human activities driving the trends using Landsat TM imagery. The study utilized both spatial and non-spatial datasets from primary sources (Landsat imagery via Google Earth Engine and field surveys) and secondary sources (literature and government reports). Landsat 5 (2004) and Landsat 8 (2014, 2024) images were processed using Arc-GIS and QGIS to minimize cloud interference. Land cover classification combined unsupervised and supervised methods, validated with ground reference points collected through GPS. A rule-based classification system used spectral indices to identify land cover types. Classified maps were visualized and exported for further analysis. Furthermore, systematic field visits were conducted along the catchment to assess human land use activities, that is, agriculture, settlements, and deforestation. Results revealed a 17.6% decline in sparse vegetation between 2004 and 2014, and a further 27.01% decrease from 2014 to 2024. Bare land increased by 8.58% over the two decades. Built-up areas rose from 0.67% in 2004 to 5.44% in 2014, then dropped to 2.1% in 2024. In contrast, dense vegetation increased from 0.04% in 2004 to 7.13% in 2024. Overall, the land cover projection for 2034 indicates continued ecological transformation within the Ngerengere River catchment. These shifts, primarily driven by agricultural expansion and deforestation, underscore the urgent need for sustainable land management. The significant vegetation cover decline in the catchment is largely due to agricultural encroachment into forested areas.

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