A team of botanists from three continents set out in search of Karomia gigas, a Critically Endangered tree with fewer than 20 remaining individuals estimated to be surviving in the wild. Emily Beech describes the trials and tribulations in the search for the seed.
In October 2016, GTC led a survey trip to look for Karomia gigas, a tree now found only in southeast Tanzania.
History of the tree
Karomia gigas was previously known from a single individual tree in Kenya, which was cut down in the late 1970’s. Another individual was then identified in Tanzania in 1993, but when this specimen could no longer be found, it was feared that the species had become extinct.
However in 2012, a previously unknown population was discovered in Tanzania by botanists from the University of Dar es Salaam, 28 km away from the site of the 1993 specimen. Therefore, although not extinct, Karomia gigas is still only known from fewer than 20 trees and clearly required urgent action to increase the population.
A rocky start
As with many a botanising trips, the expedition got off to a rocky start. The known trees are located several kilometres from the main road, along a difficult, dusty, weaving track through Miombo woodland. The first day was sadly cut short when one of our vehicles got stuck in deep ruts in the track and with rumours that there were leopards in the area, we were pleased to get the vehicle moving again just before sunset.
If at first you don’t succeed…
The group returned to the forest early the next morning, navigating carefully along the same track, reaching as far as the car could go without getting stuck again. We had enlisted the help of Mr. Salim Jangwa, a member of the nearest village, whose knowledge of the forest was invaluable to help us locate the trees we were looking for. He led us for over an hour on foot winding through dry, hot, coastal forest. After months of drought, the forest was almost silent, with few signs of wildlife, birds or insects. The dominant vegetation was small, leafless trees, with the odd flash of colour from the bright red native Hibiscus and coral red Erythrina flowers through the open forest.
And then at last, we spotted our first Karomia tree. Towering over the other vegetation in the forest, the tree rose straight upwards from the forest floor with a patchy grey/yellow bark. We found six individual trees of Karomia gigas, all with similar impressive trunks. Herbarium specimens collected in the past at the same time of year as our survey, had suggested the trees would have seed available at the time of the trip. Although we did find seed, the seeds were not fresh and therefore unlikely to be viable. There were no signs of natural regeneration. A sample of seeds was however taken to the Tanzania Tree Seed Agency (TTSA) for viability testing.
During our mission we appointed Mr. Jangwa as a tree surveyor. He will monitor the trees twice a month to report when flowers and seed are present. GTC has managed to raise further funds for a seed collecting trip, so when we are informed that fresh seed is available, a trained team can go out to collect these rare and valuable seeds. Funding has also been secured to survey the only other known population of Karomia gigas, which is estimated to consist of nine trees. The survey will take place alongside seed collection at the first site in the hope that seed will also be available for collection from the second population.
The aim of the seed collection is to establish a genetically representative seed collection at TTSA and coastal botanic gardens in Tanzania. A local propagation programme will be initiated to enable restoration at the current site. These efforts represent hope for the future of this Critically Endangered tree which, with no current formal protection in place despite high deforestation rates in the region, is at great risk of being lost forever.
The expedition was funded by the Mohamed bin Zayed Species Conservation Fund.
A version of this article previously featured in BGCI’s BG journal, published in January 2017