Anthropogenic Activities Shape Bee Species Diversity and Composition in Biharamulo-Kahama Forest Reserve in Tanzania

Ng’hwale Ozano Bubinza; Paulo John Lyimo; Ezekiel Edward Mwakalukwa

doi:10.37284/eajab.8.2.4058

Ng’hwale Ozano Bubinza Sokoine University of Agriculture
Paulo John Lyimo Sokoine University of Agriculture
Ezekiel Edward Mwakalukwa Sokoine University of Agriculture

DOI: https://doi.org/10.37284/eajab.8.2.4058

Keywords: Bee Communities, Biodiversity Loss, Pollinator Decline, Miombo Woodlands, Human Disturbances, Habitat Loss, Ecosystem Services

Share Article:

Abstract

Bees are vital pollinators that sustain biodiversity, ecosystem stability, and agricultural production, yet their populations are increasingly threatened by anthropogenic disturbances. This study assessed the effects of human disturbances on bee diversity and composition in the Biharamulo–Kahama Forest Reserve (BKFR), northwestern Tanzania. Five sites adjacent to nearby villages were purposively selected based on accessibility, proximity to the forest, and evidence of human disturbances. Bee communities were comprehensively sampled across 40 plots within the forest using complementary UV-reflecting pan traps and standardised random walks. The plots, each measuring 50 m × 50 m, were systematically established at 100 m intervals from the forest edge toward the interior. A total of 908 bee individuals representing 47 species and four families were recorded. Species richness and Shannon–Wiener diversity index and evenness were significantly higher in undisturbed plots S=37, H’=3.24, J’=0.897) compared to disturbed plots (S=35, H’=2.80, J’=0.788). Family Halictidae contributed about 51% of the species. The community was numerically dominated by Apis mellifera, which also showed the highest frequency of occurrence overall. Anthropogenic activities recorded included fire (15%), charcoal making (10%), grazing (9%), tree cutting (9%), farming (6%), debarking (6%), and footpaths (2%). Generalised Linear Model (GLM) analysis revealed that fire significantly reduced bee diversity (p < 0.001), while other disturbances showed weak or non-significant effects. These findings demonstrate that anthropogenic activities, particularly fire, negatively affect bee diversity by altering habitat structure, floral resources, and nesting opportunities. The study highlights the ecological importance of conserving intact Miombo woodlands and recommends effective fire management, regulation of charcoal production, and community-based conservation as key strategies to safeguard pollinators and the ecosystem services they provide.

Downloads

Download data is not yet available.

References

Biesmeijer, J. C., Roberts, S. P. M., Reemer, M., Ohlemüller, R., Edwards, M., Peeters, T., & Kunin, W. E. (2006). Parallel declines in pollinators and insect-pollinated plants in Britain and the Netherlands. Science, 313(5785), 351–354.

Brown, M. J. F., & Paxton, R. J. (2009). The conservation of bees: A global perspective. Apidologie, 40(3), 410–416.

Classen, A., Eardley, C. D., Hemp, A., Peters, M. K., Peters, R. S., Ssymank, A., & Steffan‐Dewenter, I. (2020). Specialization of plant–pollinator interactions increases with temperature at Mt. Kilimanjaro. Ecology and Evolution, 10(4), 2182–2195.

Goulson, D., Nicholls, E., Botías, C., & Rotheray, E. L. (2015). Bee declines driven by combined stress from parasites, pesticides, and lack of flowers. Science, 347(6229), 1255957.

Klein, A. M., Vaissiere, B. E., Cane, J. H., Steffan-Dewenter, I., Cunningham, S. A., Kremen, C., & Tscharntke, T. (2007). Importance of pollinators in changing landscapes for world crops. Proceedings of the Royal Society B: Biological Sciences, 274(1608), 303–313.

Lasway, J., Kinabo, N., Mremi, R., Martin, E., Nyakunga, O., Sanya, J., ... & Njovu, H. (2021). Occurrence of bee pollinator species along agricultural and grazing gradients in northern Tanzania. GBIF.

Makwinja, R., Maleko, D. D., & Malekela, R. (2025). Fire regimes and Miombo woodland regeneration: Ecological implications. African Journal of Ecology, 63(1), 12–24.

Msuya, T. S., Masanja, V. G., & Temu, R. P. C. (2011). Environmental burden of charcoal production and use in Dar es Salaam, Tanzania. Journal of Environmental Research, 5(2), 47–56.

Munyuli, M. T. (2011). Pollinator biodiversity in Uganda and Sub-Saharan Africa: Landscape and habitat management strategies for its conservation. International Journal of Biodiversity and Conservation, 3(11), 551–609.

Ochungo, P., Veldtman, R., Abdel-Rahman, E. M., Muli, E., Ng’ang’a, J., Tonnang, H. E., & Landmann, T. (2022). Fragmented landscapes affect honey bee colony strength at diverse spatial scales in agroecological landscapes in Kenya. Ecological Applications, 32(1), e02483.

Potts, S. G., Biesmeijer, J. C., Kremen, C., Neumann, P., Schweiger, O., & Kunin, W. E. (2010). Global pollinator declines: Trends, impacts and drivers. Trends in Ecology & Evolution, 25(6), 345–353.

Potts, S. G., Imperatriz-Fonseca, V., Ngo, H. T., Aizen, M. A., Biesmeijer, J. C., Breeze, T. D., & Vanbergen, A. J. (2016). Safeguarding pollinators and their values to human well-being. Nature, 540(7632), 220–229.

Stein, K., Stenchly, K., Coulibaly, D., Pauly, A., Dimobe, K., Steffan‐Dewenter, I., & Linsenmair, K. E. (2018). Impact of human disturbance on bee pollinator communities in savanna and agricultural sites in Burkina Faso, West Africa. Ecology and Evolution, 8(13), 6827–6838.

Winfree, R., Aguilar, R., Vázquez, D. P., LeBuhn, G., & Aizen, M. A. (2009). A meta‐analysis of bees’ responses to anthropogenic disturbance. Ecology, 90(8), 2068–2076.

Zattara, E. E., & Aizen, M. A. (2021). Worldwide occurrence records suggest a global decline in bee species richness. One Earth, 4(1), 114–123. https://doi.org/10.1016/j.oneear.2020.12.005