Our Planet Reviewed - Expedition Papua New-guinea

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Land based mission

Why Papua New Guinea?


Papua New Guinea is exceptional in more ways than one; it has the third largest area of intact rainforest, after those of the Amazon basin and the Congo, and it is estimated that the country is home to around 5% of the world’s biodiversity, despite the fact that it represents only 0.5% of the world’s landmass. The country is like a ‘mini-continent’, large enough to generate its own diversity, with a very high level of endemism; over 70% of its plants do not grow anywhere else in the world. 

Although the country’s flora and fauna have not been extensively studied (the first book on mammals in Papua New Guinea was published in 1990!), they have nevertheless been the subject of important studies in the field of determining the number of species living on our planet. However, these studies looked at lowland forests, and not at mountain forests, which are not necessarily comparable. 

The land-based part of the expedition will be looking at Madang province, one of the few places in the world where the tropical rainforest extends from the coast inland up to its natural altitudinal limit, which provides excellent conditions for researchers: thanks to this new phase of The Planet Reviewed, researchers will be able to study how plants and animals spread and interact according to altitude on a large tropical mountain. 

The specimens and data collected will enable several objectives to be achieved: 

  • Improve understanding of biodiversity according to altitude in tropical rainforests. This knowledge could help to improve the current model used to calculate the number of species living on the planet; it will also enable the impact of climate change to be measured more effectively in these regions.


  • Encourage local communities to take part in the collection of data on their environment, and promote their involvement in conservation programmes. 


  • Contribute to the training of Papuan Para-taxonomists and Para-ecologists, with the aim of combining modern biology with traditional knowledge of the field.
Au pied du Mont Wilhelm, à 3700m les lacs Aunde et Piunde

Au pied du Mont Wilhelm, à 3700m les lacs Aunde et Piunde

Au pied du Mont Wilhelm, à 3700m les lacs Aunde et Piunde, servent de décors au site d'étude le plus élevé du profil altitudinal [© Xavier Desmier / MNHN / PNI / IRD].

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A vanishing paradise of biodiversity?


Papua New Guinea’s unique biodiversity is seriously threatened by human activity, in particular by the rampant deforestation which is eroding the country’s forests. A recent study led by researchers at the University of Papua New Guinea showed that the rate of deforestation has been accelerating since the early 1990s. The main reasons for this are logging, and the conversion of forest to agricultural land. To a lesser extent, forest fires, plantations and mining are also causing damage. Between 1972 and 2002, 15% of Papua New Guinea’s forests disappeared, more than half of this was due to logging. Foreign logging companies export wood from Papua New Guinea all over the world. At the present rate of deforestation, it is estimated that almost all accessible forests will have shrunk dramatically, or will simply have disappeared within ten to twenty years. 

In common with many other developing countries, Papua New Guinea is facing the challenge of integrating into the global economy without destroying its rich natural heritage. Fortunately, unlike other countries, Papua New Guinea has the advantage that its Constitution recognises and protects the rights of local communities to own land. Thanks to this, 97% of land is owned by individuals or village-based communities, who make decisions about how to use the land. 

Often, village communities agree to assign prospecting and mining rights in exchange for financial compensation, however this is not always the case. In the Wanang region, eight clans turned down government offers to use their land for logging, instead declaring their 10,000 hectares of forest a “conservation area”. With the help of Binatang Research Centre, which sponsors the village primary school, these communities are maintaining the integrity of their forest and are benefitting from biodiversity studies. These enhance the region and provide important data to guide conservation policies. In the Mount Wilhelm national park, other communities are taking part in similar, albeit smaller scale projects. Perhaps the outcome of these projects will be the bringing about of greater awareness concerning the conservation of Papua New Guinea’s forests, which is in itself very important for this country that is very involved with the Rainforest Coalition, a global partnership for the protection of rainforests, was set up in 2010.

Forêt de brouillard à 2 200 m

Forêt de brouillard à 2 200 m

Forêt de brouillard à 2 200 m. Les Pandanus (au deuxième plan, derrière les fougères) sont partout présents dans le sous-bois sur le Mont Wilhelm [© Olivier Pascal / MNHN / PNI / IRD].

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The threat of climate change


Logging is not the only threat to the forests of Papua New Guinea. Current models for measuring the impact of ongoing climate change suggest profound changes to ecosystems, in particular at higher altitudes. If temperatures rise in the region, it is highly likely that lowland species will gain ground on mountain species, which are better adapted to colder environments, leading to the destruction of tropical ecosystems. Previous studies have already documented this type of change, but only in temperate regions, or on the neighbouring island of Borneo. These changes would almost certainly have a different impact in Papua New Guinea, one of the rare places in the tropics where tropical rainforests and alpine ecosystems can be found side by side. 

Detailed data collected during the expedition will provide an inventory of the state of biodiversity (essentially of plants and invertebrates) at various different altitudes, from the lowlands up to 3,700 metres. This data will enable, for example, simulations to be carried out in order to estimate the impact of global warming of a few degrees over the next 100 years on the distribution of different species of plants and animals: which will see their distribution increased or decreased? Consequently, which conservation measures should be taken in order to prepare for these changes, and if possible minimise them?