Tree Cassava, Pigeon Wood and Iron Wood conquering Pugu Forest

The first orientation visit to the Pugu Forest on Sunday February 12th, 2012 after many years of absence resulted in both positive and negative surprises. We inspected some of the old trails and had to conclude that only the valley of the water reservoir supplying Kisarawe Town is worthwhile for a hike. This can be extended to the Wazaramu Cave were ancestral worship ceremonies (Tambiko) used to take place. We did not really make it to the cave due to the fallen trees from illegal clearing activities blocking the track. The next trip we will further investigate if a short climb to the top of the hill with the TAZARA radio tower will provide a nice loop for a hike from the Pugu Hills following the tracks on the German colonial map from 1898. Although logging is claimed to be reduced - and we did not hear nor meet anybody on that Sunday - the continuous clearing of the remaining forest patches is still evident and conservation focus should be on the valley concerned. Not only for Nature, but also for the water supply of Kisarawe. The brownish water in the reservoir is a result of the clearing of the forest in the reservoir's catchment area. Also the swamp upstream of the reservoir has been drained by deepening the feeding stream which was previously flooding the valley.Some cleared sections of the forest have been invaded by Ceara rubber tree (Manihot glaziovii) or Tree Cassave and Pigeon Wood (Trema orientalis).

Pigeon_wood Pigeon Wood (Trema orientalis). Both species are fast growing and invasive species from South America and Asia. The Tree cassava can reach even 10 to 20 meter of height but at that length it will break when exposed to strong winds. Pigeon Wood is fast growing but short lived. Both do however prevent the erosion of the very thin soil layer on top of the weathered clay soil and sandstone close to the surface in the Pugu Hills. A third invasive species which has occupied parts of the boundary sections of the Pugu Forest are planted as boundary tree. The "Iron Wood"
iron_wood_covered_clearings In 2009 a major bush fire which jumped from the shambas into the already thinned out South-western corner of the forest, cleared a few hundred meters of forest and the area was eventually invaded by the Iron Wood (Senna siamea). According to Rocky ,J, and Mligo, C. Iron Wood could not suppress the regeneration of indigenous tree species rather co-exists with the regenerating indigenous species, which would imply that the patches of Senna siamea could act as "framework trees" (see weblink)

 

Manihot glaziovii invasion_reduced

A section in the Centre of the photograph has been cleared from the original forest and is now entirely covered by Tree Cassave and Pigeon Wood other similar patches can be distinguished on the same photograph.

Bamboo is not harvested and has been expanding during the last years. Along the dry riverbed downstream of the dam a lovely lane winds along the patches of Green Bamboo (Bambusa vulgaris). The Eastern bearded robin chat known from the opening tune of this website, was very much present in the valley with ten birds or more singing their Sunday afternoon boogie.

Most appreciated was the absence of any sound from Dar es Salaam, even on the top of the hills, perhaps the most precious asset of the Pugu Forest with the town continuously expanding and become more noisy.

In case you are interested to visit the Pugu Forest a permit is required for 10usd (non-citizens). Tanzanian citizens get a permit for 1,500 tshs. If you inform us in advance we will follow up for you (we charge a surcharge of 2 usd per ticket). The procedure to obtain the permit is not yet fully client-friendly and will need some phone calls and sending of staff to Kisarawe.