La forêt du Congo, ce poumon vert si fragile (en images)
Au-dessus de la canopée, les scientifiques auscultent la forêt du bassin du Congo, pendant que dans les villages environnants des paysans s’initient à des techniques de culture moins dévastatrices pour ce « poumon vert » menacé, essentiel à la lutte contre le changement climatique.
La « tour à flux » de 55 mètres de haut, qui permet de quantifier le carbone absorbé ou émis par la forêt, se dresse dans le décor luxuriant de la réserve de biosphère de Yangambi, qui couvre quelque 250.000 hectares en bordure du fleuve Congo, dans la province de la Tshopo (nord-est de la République démocratique du Congo).
L’installation haute de 55 mètres, dont 15 mètres au dessus de la canopée, a été construite par des chercheurs belges de l’Université de Gand (UGent). Le site, réputé du temps de la colonisation belge pour ses recherches en agronomie tropicale, accueillait cette semaine une réunion de scientifiques dans le cadre d’une « pré-COP » prévue début octobre à Kinshasa, en amont de la 27e Conférence sur le climat (COP27) de novembre en Egypte.
Les tours à flux sont nombreuses dans le monde, mais le bassin du Congo n’en avait pas encore, « ce qui limitait la compréhension de cet écosystème et son rôle dans le changement climatique », explique le chef de projet Thomas Sibret, de l’UGent. Les relevés de la tour « CongoFlux », opérationnelle depuis fin 2020, doivent être analysés sur la durée, poursuit le scientifique, mais une chose est sûre, cette forêt tropicale séquestre plus de gaz à effet de serre qu’elle n’en rejette.
Le Congo, deuxième poumon vert du monde
« On parle souvent du premier poumon, l’Amazonie, et du deuxième, le bassin du Congo« , développe Paolo Cerutti, expert du Centre pour la recherche forestière internationale (Cifor) et chef des opérations menées en RDC par cet organisme basé en Indonésie. « Cela reste à ce niveau, mais, selon le forestier, on commence à avoir des preuves que l’Amazonie devient plutôt un émetteur ». « On mise donc beaucoup sur le bassin du Congo, notamment la RDC qui a 160 millions d’hectares de forêt encore capables d’absorber le carbone« . Mais là aussi la forêt est menacée: « l’année passée, le pays a perdu un demi-million d’hectares », dit-il. L’exploitation industrielle ou illégale contribue à la déforestation, mais la raison principale est selon lui « l’agriculture itinérante sur brûlis« .
Les villageois cultivent, récoltent et, quand la terre s’appauvrit et que les rendements diminuent, ils vont plus loin, défrichent, brûlent, et recommencent. Avec l’explosion démographique, la forêt risque de disparaître. « On la pensait inépuisable… Mais ici, il n’y a plus d’arbres », se désole Jean-Pierre Botomoito, chef de secteur à Yanonge, à 40 km de Yangambi.
Il faut parcourir de longues distances, à pied ou à vélo sur des sentiers étroits et boueux, pour trouver les chenilles qui colonisent certains arbres et que les Congolais adorent manger. Ou pour avoir de quoi fabriquer du charbon de bois, appelé « makala », qui, faute d’électricité, est abondamment utilisé pour la cuisine. Depuis cinq ans, le projet « FORETS » (Formation, Recherche, Environnement dans la Tshopo), largement financé par l’Union européenne, tente de sédentariser les paysans tout en leur permettant de mieux vivre de leurs champs et de la forêt.
Ferme pilote
Dans les parcelles, on alterne les cultures, on plante manioc et arachides entre des acacias à croissance rapide, qui après six ans pourront servir à la production de makala. Des pépinières alimentent le reboisement. Une « ferme pilote » montre comment tirer le meilleur parti d’une exploitation, avec ici des ananas, là une porcherie. On explique aux bûcherons comment sélectionner les arbres. Des « fours améliorés » permettent d’obtenir plus de makala. Pour le bois d’oeuvre, une scierie est à la disposition des exploitants artisanaux légaux pour produire de belles planches d’afrormosia, bois rouge, iroko, kosipo…
Un laboratoire de biologie du bois aide à prédire l’évolution de la forêt. L’herbarium, sanctuaire de milliers de plantes séchées collectées depuis les années 1930, a été rénové. Et les responsables du « programme national de recherche sur les caféiers » rêvent de renaissance de la filière café, mise à terre par la mauvaise gestion, les maladies, les conflits armés. « Nous sommes agriculteurs, mais nous n’avions pas forcément les bonnes pratiques« , admet Jean Amis, dirigeant d’une organisation paysanne.
Pas toute le monde est enthousiaste
Hélène Fatouma, qui préside une association de femmes, est ravie que les étangs piscicoles autour desquels gambadent canards, poules et chèvres aient donné 1.450 kg de poisson en six mois, contre 30 kg auparavant. Dans une clairière noircie écrasée de chaleur, Doloka, 18 ans, sort des braises d’un four encore fumant et se réjouit à l’idée que « la forêt revienne près de la maison ». D’autres villageois sont nettement moins enthousiastes.
Certains pensent que la tour à flux vole l’oxygène, d’autres qu’on veut leur prendre leurs terres, des dendromètres fixés sur des troncs pour mesurer leur croissance sont vandalisés, des chefs restent convaincus que les arbres repoussent tout seuls et que les programmes successifs n’enrichissent que leurs promoteurs. Les équipes du Cifor espèrent que la sensibilisation et l’éducation vaincront les résistances. Le directeur du centre de recherche de l’Inera (Institut national pour l’étude et la recherche agronomique), Dieu Merci Assumani, veut même croire à « l’adhésion de tous ».
Mais « les moyens manquent », regrette-t-il, en déplorant que les communautés congolaises ne voient pas venir les « financements carbone » promis par les « pays pollueurs » en échange de la protection de la forêt. « Des engagements, c’est bien, mais il faut des décaissements », s’agace-t-il.
Interrogé sur la récente mise aux enchères de blocs pétroliers, dont un tout proche de Yangambi, M. Assumani se dit par ailleurs favorable à l’exploitation pétrolière, dans le « respect du principe de gestion durable ». A l’inverse de certains défenseurs de l’environnement, il pense que « ce sera une bonne chose« , pour le pays et pour l’Afrique.
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A scientist inspects the devices installed in the trees in the Yangambi Biosphere Reserve, 100 km from the city of Kisangani, Tshopo Province, northeastern Democratic Republic of Congo, September 2, 2022. – The 55-meter high Flux Tower, which quantifies the carbon, absorbed or emitted by the forest, stands in the lush setting of the Yangambi biosphere reserve, which covers some 250,000 hectares along the Congo River, in the province of Tshopo. (Photo by Guerchom Ndebo / AFP)
2/19
A woman prepares food for her family in the backyard of her plot in Yangambi, 100 km from the city of Kisangani, in Tshopo province, northeastern Democratic Republic of Congo, September 2, 2022. (Photo by Guerchom Ndebo / AFP)
3/19
This aerial view shows trees in the Yangambi forest with the flux tower, 100 km from the city of Kisangani, in the Tshopo province, northeast of the Democratic Republic of the Congo on September 2, 2022. – The 55-meter high Flux Tower, which quantifies the carbon, absorbed or emitted by the forest, stands in the lush setting of the Yangambi biosphere reserve, which covers some 250,000 hectares along the Congo River, in the province of Tshopo. (Photo by Guerchom Ndebo / AFP)
4/19
Thomas Sibret, scientist and student at the University of Ghent, verifies the devices installed in the trees in the Yangambi Biosphere Reserve, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of Congo, on September 2, 2022 – The 55-meter high Flux Tower, which quantifies the carbon, absorbed or emitted by the forest, stands in the lush setting of the Yangambi biosphere reserve, which covers some 250,000 hectares along the Congo River, in the province of Tshopo. (Photo by Guerchom Ndebo / AFP)
5/19
Gabali Lingimbe (R), wife of a National Institute for Agronomic Study and Research (INERA) civil servant who died a few years ago, sitts in front of his house in Yangambi, 100 km from the city of Kisangani, in the province of Tshopo, in the northeast of the Democratic Republic of Congo on September 2, 2022. – After the death of her husband, Gabali dedicated herself to survive with her family. Despite her husband being a public servant, the DRC government does not provide for the family after his death. (Photo by Guerchom Ndebo / AFP)
6/19
Young workers from the Yangambi pilot farm look at the state of production in a field in front of them (not visible) in Yangambi, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of the Congo on September 1, 2022. – The pilot farm is an initiative supported by Center for International Forestry Research (CIFOR) to help the community and scientists understand how a crop behaves before it is sustained on a large scale. (Photo by Guerchom Ndebo / AFP)
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A general view of of trees in the Yangambi forest, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of Congo on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
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Elasi Ramazani (L), 69, director of the Yangambi Herbarium and a scientist for nearly 25 years, talks with another scientist in the room where they study herbs in Yangambi, 100 km from the city of Kisangani, Tshopo province, northeastern Democratic Republic of Congo, on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
9/19
People walk along a road covered by primary forest in Yangambi Biosphere Reserve, 100 km from the city of Kisangani, in Tshopo Province, northeastern Democratic Republic of Congo, on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
10/19
People walk along a road covered by primary forest in Yangambi Biosphere Reserve, 100 km from the city of Kisangani, in Tshopo Province, northeastern Democratic Republic of Congo, on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
11/19
Robert Lokombe, 27, a forestry engineer, prepares herbarium labels for better classification and referencing during the digitisation at the herbarium in Yangambi, 100 km from the city of Kisangani, in Tshopo province, northeastern Democratic Republic of Congo, on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
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Elasi Ramazani (L), 69, director of the Yangambi Herbarium and a scientist for nearly 25 years, talks with other scientists in the room where they study herbs in Yangambi, 100 km from the city of Kisangani, Tshopo province, northeastern Democratic Republic of Congo, on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
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Odin Akatikale, 35, carves into wood samples in Yangambi, 100 km from the city of Kisangani, in the northeastern province of Tshopo, Democratic Republic of Congo, September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
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A general view of a rainbow seen on the pilot farm in Yangambi, 100 km from the city of Kisangani, in the province of Tshopo, northeastern Democratic Republic of Congo on September 1, 2022. – The pilot farm is an initiative supported by Center for International Forestry Research (CIFOR) to help the community and scientists understand how a crop behaves before it can be sustained on a large scale. (Photo by Guerchom Ndebo / AFP)
15/19
This aerial view shows trees in the Yangambi forest with the Flux Tower, 100 km from the city of Kisangani, in the Tshopo province, northeast of the Democratic Republic of the Congo on September 2, 2022. – The 55-meter high Flux Tower, which quantifies the carbon, absorbed or emitted by the forest, stands in the lush setting of the Yangambi biosphere reserve, which covers some 250,000 hectares along the Congo River, in the province of Tshopo. (Photo by Guerchom Ndebo / AFP)
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Patric, who lives in Yangambi, clears the road for a car after a tree fell in the way, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of Congo on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
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Nestor Luambua (L), who is in charge of the wood laboratory, explains how the laboratory works in Yangambi, 100 km from the city of Kisangani, in the Tshopo province, northeast of the Democratic Republic of Congo, on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
18/19
This aerial view shows trees in the Yangambi forest, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of Congo on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
19/19
People stand in front of the administrative building of the National Institute for Agronomic Study and Research (INERA) in Yangambi, 100 km from the city of Kisangani, in the province of Tshopo, in the northeast of the Democratic Republic of the Congo on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
1/19
A scientist inspects the devices installed in the trees in the Yangambi Biosphere Reserve, 100 km from the city of Kisangani, Tshopo Province, northeastern Democratic Republic of Congo, September 2, 2022. – The 55-meter high Flux Tower, which quantifies the carbon, absorbed or emitted by the forest, stands in the lush setting of the Yangambi biosphere reserve, which covers some 250,000 hectares along the Congo River, in the province of Tshopo. (Photo by Guerchom Ndebo / AFP)
2/19
A woman prepares food for her family in the backyard of her plot in Yangambi, 100 km from the city of Kisangani, in Tshopo province, northeastern Democratic Republic of Congo, September 2, 2022. (Photo by Guerchom Ndebo / AFP)
3/19
This aerial view shows trees in the Yangambi forest with the flux tower, 100 km from the city of Kisangani, in the Tshopo province, northeast of the Democratic Republic of the Congo on September 2, 2022. – The 55-meter high Flux Tower, which quantifies the carbon, absorbed or emitted by the forest, stands in the lush setting of the Yangambi biosphere reserve, which covers some 250,000 hectares along the Congo River, in the province of Tshopo. (Photo by Guerchom Ndebo / AFP)
4/19
Thomas Sibret, scientist and student at the University of Ghent, verifies the devices installed in the trees in the Yangambi Biosphere Reserve, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of Congo, on September 2, 2022 – The 55-meter high Flux Tower, which quantifies the carbon, absorbed or emitted by the forest, stands in the lush setting of the Yangambi biosphere reserve, which covers some 250,000 hectares along the Congo River, in the province of Tshopo. (Photo by Guerchom Ndebo / AFP)
5/19
Gabali Lingimbe (R), wife of a National Institute for Agronomic Study and Research (INERA) civil servant who died a few years ago, sitts in front of his house in Yangambi, 100 km from the city of Kisangani, in the province of Tshopo, in the northeast of the Democratic Republic of Congo on September 2, 2022. – After the death of her husband, Gabali dedicated herself to survive with her family. Despite her husband being a public servant, the DRC government does not provide for the family after his death. (Photo by Guerchom Ndebo / AFP)
6/19
Young workers from the Yangambi pilot farm look at the state of production in a field in front of them (not visible) in Yangambi, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of the Congo on September 1, 2022. – The pilot farm is an initiative supported by Center for International Forestry Research (CIFOR) to help the community and scientists understand how a crop behaves before it is sustained on a large scale. (Photo by Guerchom Ndebo / AFP)
7/19
A general view of of trees in the Yangambi forest, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of Congo on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
8/19
Elasi Ramazani (L), 69, director of the Yangambi Herbarium and a scientist for nearly 25 years, talks with another scientist in the room where they study herbs in Yangambi, 100 km from the city of Kisangani, Tshopo province, northeastern Democratic Republic of Congo, on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
9/19
People walk along a road covered by primary forest in Yangambi Biosphere Reserve, 100 km from the city of Kisangani, in Tshopo Province, northeastern Democratic Republic of Congo, on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
10/19
People walk along a road covered by primary forest in Yangambi Biosphere Reserve, 100 km from the city of Kisangani, in Tshopo Province, northeastern Democratic Republic of Congo, on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
11/19
Robert Lokombe, 27, a forestry engineer, prepares herbarium labels for better classification and referencing during the digitisation at the herbarium in Yangambi, 100 km from the city of Kisangani, in Tshopo province, northeastern Democratic Republic of Congo, on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
12/19
Elasi Ramazani (L), 69, director of the Yangambi Herbarium and a scientist for nearly 25 years, talks with other scientists in the room where they study herbs in Yangambi, 100 km from the city of Kisangani, Tshopo province, northeastern Democratic Republic of Congo, on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
13/19
Odin Akatikale, 35, carves into wood samples in Yangambi, 100 km from the city of Kisangani, in the northeastern province of Tshopo, Democratic Republic of Congo, September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
14/19
A general view of a rainbow seen on the pilot farm in Yangambi, 100 km from the city of Kisangani, in the province of Tshopo, northeastern Democratic Republic of Congo on September 1, 2022. – The pilot farm is an initiative supported by Center for International Forestry Research (CIFOR) to help the community and scientists understand how a crop behaves before it can be sustained on a large scale. (Photo by Guerchom Ndebo / AFP)
15/19
This aerial view shows trees in the Yangambi forest with the Flux Tower, 100 km from the city of Kisangani, in the Tshopo province, northeast of the Democratic Republic of the Congo on September 2, 2022. – The 55-meter high Flux Tower, which quantifies the carbon, absorbed or emitted by the forest, stands in the lush setting of the Yangambi biosphere reserve, which covers some 250,000 hectares along the Congo River, in the province of Tshopo. (Photo by Guerchom Ndebo / AFP)
16/19
Patric, who lives in Yangambi, clears the road for a car after a tree fell in the way, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of Congo on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
17/19
Nestor Luambua (L), who is in charge of the wood laboratory, explains how the laboratory works in Yangambi, 100 km from the city of Kisangani, in the Tshopo province, northeast of the Democratic Republic of Congo, on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
18/19
This aerial view shows trees in the Yangambi forest, 100 km from the city of Kisangani, in the province of Tshopo, northeast of the Democratic Republic of Congo on September 2, 2022. (Photo by Guerchom Ndebo / AFP)
19/19
People stand in front of the administrative building of the National Institute for Agronomic Study and Research (INERA) in Yangambi, 100 km from the city of Kisangani, in the province of Tshopo, in the northeast of the Democratic Republic of the Congo on September 2, 2022. – The site, renowned during the time of Belgian colonisation for its research in tropical agronomy, hosts a herbarium that has more than 6000 species. (Photo by Guerchom Ndebo / AFP)
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