Diversity and composition of preserved angiosperm specimens at Tanzania Forestry Research Institute (TAFORI) Herbarium

Study Extent

Specimen preserved at Lushoto Silviculture Research Center were collected from different regions in Tanzania.

Sampling

Data presented in this data set were collected during implementation of various research projects in Tanzania. Plant materials were collected and pressed in the field, dried, identified and mounted on sheet bearing detailed labels, preserved and fixed into folders, then stored in cabinet’s cardboards systematically and sequentially (Alexiades, 1996). Every sheet of specimens contains standard information for herbarium collections, including; taxonomic identification, locality information, geographical coordinates, collector information, and ecological data. In addition, the specimens have been treated to prevent pests damage

Method steps

1. The information on the specimen labels was our data source. To digitize each specimen, we followed three steps: data capture, data cleaning, and data publication. In the data capture process, we extracted all the information on the specimen’s label, and we input the information into Microsoft Excel spreadsheets using Darwin-Core format. In this process, we grouped the specimen information into specific categories of Darwin Core data standards. We used “GEOlocate” (https://www.geo-locate.org/default.html) to acquire the coordinates of the specimens lacking geographical coordinates. We obtained the coordinates by geo-referencing the name of the village or location written on the preserved specimen. Afterwards, we conducted data cleaning to ensure data consistency and adherence to Darwin Core standards. We mainly used “data validator” tool available under GBIF website (https://www.gbif.org/tools/data-validator) to identify missing or incorrect information in our data set. To verify the taxonomic nomenclature, we used “species matching” tool available under GBIF website (https://www.gbif.org/tools/species-lookup), the Plant list (http://www.theplantlist.org/), and World flora Online (http://www.worldfloraonline.org/). All the tools we used are open-source software or available as an open online platform.

This data set was extracted from 23,014 sheets of preserved angiosperm specimens preserved at TAFORI herbarium at Lushoto representing 227 families and1639 genera. Dominant families in this data set are Fabaceae (13.9%), Rubiaceae (9.3%) and Asteraceae (5.1%).

1. Angiosperms
   rank: species

Located within Flora of tropical East Africa (FTEA), Tanzania is one of the twelve global mega-diverse countries (Clayton et al., 1974). It is among the top five in Africa, harbouring more than one-third of the total plant species (VPO, 2015). It exhibits a high degree of plant species endemism and diversity attributed to the complex topographic, biological and microclimatic conditions. Tanzania designated an extensive network of protected areas, including twenty-two National Parks, nineteen Natural Forest Reserves, eighteen Marine Reserves, sixteen Game Reserves and three Marine Parks. Kilimanjaro National Park, Selous Game Reserve and Serengeti National Park are natural UNESCO World Heritage sites. Also, UNESCO recognises the Ngorongoro Conservation Area, composed of a spectacular Ngorongoro Crate, as a cosmopolitan World Heritage site. The Kilombero Valley, Malagarasi River, Lake Natron and Ulanga River are among the world RAMSAR sites found in Tanzania.
Specimens records presented in this dataset are from protected and non-protected areas in different geographical regions of Tanzania. Sampled areas cover a wide range of altitudinal elevations and habitats types, including; lowland tropical forest, highland forest, grasslands, montane forest and different woodlands. Also, the dataset consists few records from the United Kingdom, Uganda, Malawi, Kenya and Zambia.