27 May 2023

Uganda's botanical riches: expedition in the forest

As part of the Uganda Tropical Important Plant Areas project, we had the exciting opportunity to collect and study the hugely diverse plants of five protected areas: Semuliki National Park and Itwara, Kagorra, Kalinzu and Kasyoha-Kitomi Central Forest Reserves.

Researchers look over a wet grassland

Semuliki National Park is the lowest altitude forest in Uganda, situated in a unique position in the shadow of the Ruwenzori mountains on one side and the Democratic Republic of Congo on the other.

The forests across the border in D.R. Congo are hard to survey due to safety issues and so researching Semuliki gives a rare insight into this unique ecosystem. While terrain here is relatively flat, navigating the crater-like footprints left by forest elephants made trekking more difficult!

We saw a wide range of beautiful (and many strange) plants. Some recognisable, the elegant flowers of begonias and orchids for example, and many unlike anything we’d grow in our gardens back home!

Four Ugandan plants of wholly different shapes and sizes
Plants in the Achariaceae, begonia, coffee and caper families. © Sophie Richards, RBG Kew

This visit to Semuliki was just one of five forest locations our team journeyed to in February 2023, on the quest to obtain new valuable data in support of our Uganda Tropical Important Plant Areas initiative (TIPAs). While Semuliki falls to around 600m above sea level, we surveyed forests nearly 1000m above this in the Kalinzu Forest and crossed the equator twice on our travels.

At all of the sites, we collected plants to be pressed, dried and stored in herbaria with material divided between Makerere University Herbarium in Kampala, Kew Herbarium in London, and the East African Herbarium in Nairobi.

We need these herbarium specimens to work out which species are growing at the site. The time constraints, difficult conditions and need for equipment and reference materials makes identification in the field difficult. Having physical specimens and associated data (location, frequency, habitat for example) not only helps with identification but also allows for further study. DNA sequencing, conservation, ecological research and taxonomic revisions are all made possible by this work.

Three researchers record photographs and take notes about a plant before collection
Collecting a plant involves taking pictures and notes for to capture colours, shapes and smells that may be lost after the drying process, as well as recording plant habitat and frequency © Sophie Richards, RBG Kew

Turning fieldwork into action

Important Plant Areas (IPAs) are the most critical places in the world for wild plant and fungal diversity that can be protected and managed as specific sites.

Within the Tropical Important Plant Areas programme at Kew we are working with partners at Makerere University to identify IPAs, with the ultimate aim of promoting the conservation of plants within these priority sites. Semuliki, Itwara, Kalinzu and Kasyoha-Kitomi have all been proposed as IPAs within this project. It is important for us to work with stakeholders and experts in Uganda for these sites to be fully designated as IPAs, ensuring that we’re recognising the right sites and that their plant diversity is documented comprehensively.

Two researchers are preparing plants for pressing in layers of paper
Renata Borosova (RBG Kew) and James Kalema (Makerere University) pressing plant specimens ready for drying. © Sophie Richards, RBG Kew
A plastic bag tunnel connects a press of plant specimens to an electric heater
A stack of plant specimens in the middle of the drying process using an electric fan heater. © Renata Borosova, RBG Kew

With our collections and observations, we have increased our understanding of plants of conservation importance. For instance, at Kalinzu and Kasyoha-Kitomi we made collections of the Vulnerable tree species Musanga leo-errerae and Zanthoxylum mildbraedii, both of which have restricted distributions and are threatened by habitat loss.

A bare tree branch splits at its end into six groups of leaves, each leaf group is spread in a circular pattern from a single point
A Vulnerable tree species Musanga-leo errerae at Kalinzu Central Forest Reserve. © Sophie Richards, RBG Kew

Monitoring these species through time is important as it allows for appropriate conservation action to follow. We can also use IPA documentation to create awareness about the wellbeing of these species at each site and to recommend actions for their protection.

Alongside this, there is the exciting possibility of new records for species at a site and even species that are completely new to science. 

With some of the forests visited previously receiving extensive surveys only for the tree species present, and all of these sites initially established to manage timber resources, the herbaceous and shrubby species in the forest understorey, like those pictured in above, were of particular interest to us. Kew and Makerere will work over the coming months to identify these species from the collections made.


Researchers pose by an old roadsign labelled "Semuliki National Park"
The Uganda TIPAs collecting team (Kennedy Mukasa, Protase Rwaburindore, Sophie Richards, Renata Borosova and James Kalema) with our Uganda Wildlife Authority ranger, Sara (centre-left), at Semuliki National Park. © RBG Kew

Planning the future

Some of the species collected will trigger Important Plant Areas through meeting IPA criteria, for example if they are known to be threatened with extinction. TIPAs projects in other countries have previously been successful in guiding and motivating conservation of plant species and their habitats. In Guinea for example, IPAs have led to the establishment of 22 new protected areas, while the data collected through the Cameroon TIPAs project supported a successful bid to revoke a logging concession granted in the highly diverse Ebo Forest.  It is our hope that the identification of IPAs will support similar conservation actions in Uganda.

To achieve this requires the sharing of knowledge and experience from experts of different disciplines and backgrounds, which we set out to do alongside this phase of field surveys. In part two of this story, we share our experiences from a national plant conservation workshop we co-hosted at Makerere University, Kampala, where we worked with in-country researchers and practitioners in botany and conservation to help us identify Uganda’s IPAs.


We would like to thank our funders the players of the People’s Postcode Lottery, the Woodspring Trust and the P.F. Charitable Trust.

A group of researchers review IUCN red list assessments

Uganda’s botanical riches: a partnership in conservation

View part two of this double feature for the planning of tomorrow's conservation work in Uganda

Read & watch