Biodiversity of the Pugu Hills

The natural world contains about 8.7 million species, according to a new estimate described by scientists as the most accurate ever. Meaning this could be 2 million species more or less. Pugu Forest has been identified in a UNESCO report as a Regional Centre for plant diversity.

Just some figures.

Estimates for all plants species on our planet is 300,000 of which 70% is described. In Luxembourg (EU) 1,246 vascular plant species are distinguished, compared to 10,008 for Tanzania. The total area of Luxembourg is 2,586 km2, Tanzania is 945,087 and 1,800 km2 for Dar es Salaam.

The Kazimzumbwi Forest which is a forest reserve adjacent to Pugu Forest Reserve with a total area 0f 35.5 kmhas, according to a study in 2002, hundred and seventy two (172) plant species. This figure is impressive compared to the total tree species in the Netherlands which is with 33,393 km2 of land area which is about 50.

Even the Pugu Hills Nature Centre of 0.06 kmwill challenge the tree biodiversity of the Netherlands.

The number of birds species in Luxembourg (since 1950) is according to wikipedia 289, compared with around 500 for Dar es Salaam including the Pugu Hills (estimates are between 470 and 504). In the Pugu Hills 64 species are found which can not be seen in neighbouring Dar es Salaam.

In a report (2007) IOE. Malugu of the Wildlife Conservation Society of Tanzania (WCST) sums up all the arguments and counts which make Pugu and Kazimzumbwi to a biodiversity hotspot, but unfortunately all these claims are based on studies which do not any longer represent the present status of both forests.

Breeding birds are considered a good indicator in Europe to follow trends in biodiversity according to Birdlife international (www.birdlife.org/action/science/indicators/pdfs/eu_briefing_bird_indicator.pdf). The results for 18 European countries are illustrated in the graph below.

Birds are still surprisingly present at Pugu monitoring the breeding birds could provide some first indication in case the developments clearing the last patches of Pugu Forest are halted. It is not only the human interventions which affect the Pugu Forest. Also the climate has dramatically changed since the millenium with much less rain and opportunity for the forest to recover from human activities. Fortunately the rains of 2010 and 2011 were not as bad as the dramatic drop of the precipitation as is shown in the second graph below after the millenium.

Precipitation pattern Kisarawe

Kisarawe precipitation and temperature 1981 - 2009

But why such a fuss about the extinction of 14 endemic trees at Pugu a minor issue compared to extinction of the recently discovered Sanje Mangabay (read the alarm bell). Perhaps the Udzungwa monkey will be lost because who could be mobilised to act in time? We still assume, the Pugu Forest stands a better chance for finding support for Nature Conservation even if less spectacular. By interesting the Dar es Salaam residents, even a fraction of the 5(?) million would make a difference, in the long run possibly even in time for the Sanje Mangabay.