ABSTRACT
A dataset describing the occurrence of wild bees and their interaction with forage plants along livestock grazing gradient is critical in understanding bee-plant interaction networks and in developing conservation plans to ensure ecosystem services in human-modified landscapes. Despite this need, bee-plant datasets are scarce in Africa, and Tanzania is no exception. Therefore, in this article, we present a dataset of wild bee species richness, occurrence, and distribution collected across sites with different levels of livestock grazing intensity and forage resources thereby. The data presented in this paper supports a research article by Lasway et al., 2022 describing the effects of grazing intensity on East African bee assemblages. The paper presents primary data on bee species, collection method, date of collection, bee family, identifier, plant forage resource, forage plant life form, forage plant family, location (GPS coordinates), grazing intensity category, mean annual temperature (°C), and elevation (m asl). The data were collected intermittently between August 2018 and March 2020 from 24 study sites distributed along three levels of livestock grazing intensity with eight replicates for each: low, moderate, and high livestock grazing intensity. In each study site, two 50 × 50 m study plots were set from which bees and floral resources were sampled and quantified. The two plots were placed in a way to capture the overall structural heterogeneity of the respective habitat by placing the two plots in contrasting microhabitats where possible. For example, in moderately livestock-grazed habitats, plots were placed on sites with and without tree or shrub cover to ensure representativeness. This paper presents a dataset comprising 2,691 bee individuals from 183 species representing 55 genera of the five bee families: Halictidae (74), Apidae (63), Megachilidae (40), Andrenidae (5), and Colletidae (1). In addition, the dataset comprises 112 species of flowering plants that were identified as potential forage resources for bees. This paper supplements rare but critical data on bee pollinators in Northern Tanzania and advances our knowledge of the potential drivers of bee-pollinator whose populations diversity are declining globally. The dataset will also promote collaborations among researchers who would wish to combine and extend their data for further analysis to gain a broader understanding of the phenomenon on a larger spatial scale.
ABSTRACT
BACKGROUND: Bees (Hymenoptera: Apoidea: Anthophila) are the most important group of pollinators with about 20,507 known species worldwide. Despite the critical role of bees in providing pollination services, studies aiming at understanding which species are present across disturbance gradients are scarce. Limited taxononomic information for the existing and unidentified bee species in Tanzania make their conservation haphazard. Here, we present a dataset of bee species records obtained from a survey in nothern Tanzania i.e. Kilimanjaro, Arusha and Manyara regions. Our findings serve as baseline data necessary for understanding the diversity and distribution of bees in the northern parts of the country, which is a critical step in devising robust conservation and monitoring strategies for their populations. NEW INFORMATION: In this paper, we present information on 45 bee species belonging to 20 genera and four families sampled using a combination of sweep-netting and pan trap methods. Most species (27, ~ 60%) belong to the family Halictidae followed by 16 species (35.5%) from the family Apidae. Megachilidae and Andrenidae were the least represented, each with only one species (2.2%). Additional species of Apidae and Megachilidae sampled during this survey are not yet published on Global Biodiversity Information Facility (GBIF), once they will be available on GBIF, they will be published in a subsequent paper. From a total of 953 occurrences, highest numbers were recorded in Kilimanjaro Region (n = 511), followed by Arusha (n = 410) and Manyara (n = 32), but this pattern reflects the sampling efforts of the research project rather than real bias in the distributions of bee species in northern Tanzania.
ABSTRACT
While the international pet trade and habitat destruction have been extensively discussed as major threats to the survival of the pancake tortoise (Malacochersus tornieri), the impact of climate change on the species remains unknown. In this study, we used species distribution modelling to predict the current and future distribution of pancake tortoises in Zambezian and Somalian biogeographical regions. We used 224 pancake tortoise occurrences obtained from Tanzania, Kenya and Zambia to estimate suitable and stable areas for the pancake tortoise in all countries present in these regions. We also used a protected area network to assess how many of the suitable and stable areas are protected for the conservation of this critically endangered species. Our model predicted the expansion of climatically suitable habitats for pancake tortoises from four countries and a total area of 90,668.75 km2 to ten countries in the future and an area of 343,459.60-401,179.70 km2. The model also showed that a more significant area of climatically suitable habitat for the species lies outside of the wildlife protected areas. Based on our results, we can predict that pancake tortoises may not suffer from habitat constriction. However, the species will continue to be at risk from the international pet trade, as most of the identified suitable habitats remain outside of protected areas. We suggest that efforts to conserve the pancake tortoise should not only focus on protected areas but also areas that are unprotected, as these comprise a large proportion of the suitable and stable habitats available following predicted future climate change.