Author: Philippe Nicod

Reforestation projects are sometimes criticised for simply displacing the problem by causing deforestation on other land nearby. For this reason, this phenomenon, known as “leakage”, is measured precisely in every carbon certification project.

In this context arboRise, as in 2024, launched a Design Project in collaboration with the Ecole Polytechnique Fédérale de Lausanne (EPFL). This research project was led by Etienne de Labarrière and Aurélie Sakic, under the supervision of Charlotte Grossiord, Tenure Track Associate Professor, from the Plant Ecology Research Laboratory.

In the project region, farmers practise slash and burn agriculture: on these poor soils, cultivation quickly leads to a decline in fertility, requiring the land to be left fallow for several years to regenerate the soil. When the soil is once again fertile, the vegetation that has grown on the land is cut down and then burnt so that the ashes can transfer their mineral salts to the new crops. And so on.

Why are tropical soils poor? High humidity and high temperatures cause dead vegetation to decompose rapidly. The carbon present in dead branches, for example, escapes into the atmosphere in the form of CO2 and does not enough have time to be absorbed into the soil, so the soil lacks organic carbon. Heavy rain also washes the soil, removing nitrogen and minerals.

When you travel around the Linko region, it is striking to see that the vegetation cover is generally no more than 20 metres high. This is an indication that the entire area is subject to slash-and-burn agriculture. In fact, most of the ‘forests’ that can be seen are nothing more than more or less old fallow land. The whole perimeter is one huge field at different stages of cultivation/fallow, and true natural forests are rare.

The challenge for our two researchers was to measure clearings over a very long period, since a crop cycle lasts around 15 years (5 years of cultivation, 10 years of fallow). The second challenge is that the length of the cropping cycle is not homogeneous: it is shorter on fertile land, for example in riverbeds, and it also depends on the labour available, distance from the village, etc.

Our two specialists began by identifying, on historical aerial views of Google Earth, plots of land that are changing from woodland to cultivated land.

Two examples of change from fallow to cultivation between 2015 and 2021:

The NDVI (Normalized Difference Vegetation Index, a measure of vegetation health) values for the “wooded” year and the “cultivated” year are then compared for the coordinates of each plot, after standardising the annual NDVI using neutral zones (villages, roads, etc.). There is a significant difference in NDVI between wooded areas and cultivated or fallow areas. It is therefore possible to determine a level of NDVI above which land can be considered wooded and below which it is cultivated.

By detecting sudden drops in NDVI, we can determine for each year which areas have been cleared. In the example below, for the years 2024-2025, we can see that the area cleared in a single year (in red) is very large, confirming that slash-and-burn farming is common practice throughout the region:

Another challenge facing Aurélie and Etienne is the need to demarcate the boundaries of the villages. Because if the arboRise project leads to deforestation, it will be in the project villages and not in the others. There is no land registry in these rural communities. There is no map showing village boundaries. Our two researchers have therefore formulated some working hypotheses:

• The arboRise project plots in a given village form the outlines of a polygon which, increased by a buffer proportional to the village population, represents the village boundaries
• Natural boundaries (rivers, catchment areas) or man-made boundaries (roads) form village boundaries.

They have thus been able to define the approximate boundaries of villages:

It can be seen that these fictitious boundaries seem to correspond to reality, since the deforested areas conform to these boundaries, as in the case of the village of Massenadou :

The next step was to calculate the deforestation trend for each village:

There has been a reduction in deforestation in the villages to the north of the perimeter, whereas land clearing has increased in the villages to the south, regardless of whether or not they are part of the arboRise project. This is due either to the microclimate, with the north receiving more rainfall than the south, or to increased human pressure, with the north, far from infrastructure, becoming more depopulated than the south. These North-South variations may also be caused by the NDVI normalisation factor, taken from the average of non-arboRise villages.

This data finally brings us back to the initial question: is there an increase in deforestation in the arboRise villages because of the arboRise project?

The two scientists compared the rate of deforestation in the project villages before and after the start of activities, and the rate of deforestation from the start of the project between arboRise and non-arboRise villages. In both cases, they found no significant variation in deforestation.

Of course, it will be necessary to repeat this analysis over the next few years. It will also be necessary to increase the precision of the measurement. In fact, only the land families participating in the arboRise project could be indirectly forced by the project to increase their land clearing. For this detailed analysis, we will first have to manually delimit all the plots in the project land-families in order to check whether deforestation is increasing significantly in these specific areas. Finally, we need to prove causality.

For the arboRise project, the method adopted by our two researchers is relevant, even if it can still be refined (choice of NDVI threshold, source of data and period analysed, standardisation of NDVI, etc.). This will make it possible to check the possible collateral effects of the project year after year, in order to find solutions to them (supply of bio-fertilisers to increase the duration of crops, supply of tools to increase agricultural productivity and reduce agriculture’s footprint on the soil, choice of seeds, etc.).

Many thanks to Etienne de Labarrière and Aurélie Sakic for their major contribution to our understanding of the phenomenon of deforestation!  The whole report is available here.

The authorities of the Linko sub-prefecture have asked us to help them detect bushfires and thus facilitate the extinguishing of uncontrolled fires. As in 2024, we launched a Design Project in collaboration with the Ecole Polytechnique Fédérale de Lausanne (EPFL), led by Elena Thomas, under the supervision of Alexis Berne, Associate Professor, Environmental Remote Sensing Laboratory.

The remote sensing technologies used by arboRise to date, based on the Sentinel 2 satellite, were unable to identify all fire starts by far, due to the satellite’s long period of revolution (5 days). As for other warning systems (Global Forest Watch, Plant for the Planet’s Fire Alert), their resolution was too imprecise.

To overcome these shortcomings, our researcher opted for an innovative approach: measuring burnt areas rather than fire starts. Based on Google Earth images from 2024, in which burnt areas are clearly visible, Elena trained software to recognize areas affected by fires for each year, using Artificial Intelligence techniques.

Aerial views of burnt areas :

Model training zones :

Classification steps for zone A:

Confusion matrix to compare ground truth and model prediction :

This gives a detection accuracy of 93%, and the model can be used to map the areas burnt (in red) each year in the project area:

These images, which are almost unbelievable given the immense surface area of the burnt areas, confirm that fire is one of the main tools used by farmers and stockbreeders:

• To eliminate weeds (in place of chemical herbicides)
• To stimulate the growth of fresh grass to feed livestock in the dry season
• To bring down game when hunting
• To clear fallow land and fertilize new fields (without chemical fertilizers)
• To smoke out rodent burrows and eliminate them
• For beekeeping
• etc.

As in most neighbouring countries, preventive fires are recommended by the Guinean government after the rainy season, to prevent the build-up of stocks of combustible material that could cause devastating fires. For the most part, fires are well controlled, but sometimes they get out of hand, which is why a remote sensing system is useful.

From the perspective of the arboRise project, it is interesting to note that the area burnt has decreased since the start of our activities in Linko: 41.5% in 2019-2020 and 38.6% since 2021 (- 7.5%), which is perhaps due to our awareness-raising and incentive measures in the villages.

The analysis also makes it possible to identify the areas burnt each year on a recurring basis (below left – we can see that recurring fires correspond to river beds) and to compare them with the areas heavily reforested by arboRise (image on the right):

Intersection of the two images above:

On this basis, it is possible to identify optimal locations for a remote sensing system:

Indeed, Elena’s detailed comparison of several types of remote sensing system (drone, weather balloon, thermal camera, optical camera, etc.) showed that a network of optical cameras mounted on masts would be the most appropriate option, at a cost of around CHF 1,000 per unit. A unit capable of detecting fires 24 hours a day, 7 days a week, day and night, without human maintenance and over an area of 8 km2.

These results are extremely useful for arboRise and we would like to express our warmest thanks to Elena Thomas for her passionate commitment to this research project and her innovative results. The final report is available here, and we’ll be sure to share it with the Linko authorities and the Water and Forestry Department.

What will be the right distribution key for future carbon revenues? That’s the question the Cooperative Committee considered on 14 May.

As you will recall, one of the main objectives of the Cooperative and its Cooperative Committee, made up of democratically elected representatives from each village (the majority of whom are women), is to draw up a key for distributing carbon revenues. It is certainly not up to arboRise to define how this income will be shared among the cooperative members. This choice must be made by those directly concerned, in accordance with local traditions and customs.

To prepare for this discussion, we asked the people most directly concerned, the land families, to think about the issue during visits to each village. 88% of all cooperative members took part in this consultation, and they agreed on the following consensus:

• Compliance with the cooperative’s rules by each member should be rewarded in proportion to the effort required to comply with each rule. For example, certain ‘costly’ rules (such as the installation of firewalls around the pitches) should be better rewarded than simple rules (such as the installation of marker tape around the pitches).
• Of course, those who do a great deal to foster the growth of trees on their plots should be rewarded, but the ‘undeserving’ should also be given a little, otherwise they risk leaving the project.
• The reward should (very clearly) be based on the result (the density and height of the trees on the land) and not for the effort required to achieve this result.
• External factors (infertility of the land, fires, etc.) should not be regarded as a fatality: it is the responsibility of the landowning family if it has chosen an unsuitable site or if its land has been affected by fires.

Then, this year, we hired the “measurers” to assess the quality of maintenance on the reforested plots and the growth of the trees. In this way, the performance of each plot is known to everyone.

On 14 May we provided the Cooperative Committee with a framework for reflection to help define the key to distributing carbon income. Please note that this is not a decision but a proposal that will be submitted to the land families for approval at the Cooperative’s General Meeting.

We began by recalling the results of the ‘tarpaulin exercise’ in 2024 in all the villages, and then by presenting the results of the measuring machines and satellite observations. Each dimension (fires, compliance with the rules, tree growth according to the results of the measuring machines and satellite images) is translated into a system of points per reforested plot, which, when added together, gives a result per plot-family, which can also be analysed by village, and so on.

Despite the relative complexity of calculating points and visualising them graphically, everyone understood the principle very well.

We then asked them to discuss and decide on two points:

1. To what extent should the distribution key reward the deserving and penalise the ‘lazy’ (the adjective is from the participants!)? We explained to them that a too extreme distribution key could create major differences between the land-families and lead to conflicts. Following their deliberations, the members of the cooperative committee decided that the distribution key should lead to a small difference between the deserving and the less deserving. A wise decision
2. How do you determine the share of carbon revenue allocated to the villages? Here too, we need to balance the desire of the land families to maximise their income, and on the other hand positive impact that an amount for community infrastructure will have (or on any jealous people in the villages). The Cooperative Committee proposes that the General Assembly should vote to allocate 10% to the villages.

The members of the Comité Coopératifs first consult each other in groups, then report back to the plenary, and finally vote by raised hands.

This first exercise in reflection within the Comité Coopératif was a success. It shows that it is perfectly possible to delegate this kind of responsibility to the Cooperative’s bodies. The members are very aware of their responsibilities and a real dialogue is taking place (a deliberation, as recommended by the ethical supervision). This reflection will take place every year, before the Cooperative’s General Meeting. Over the course of those meetings, we will add elements for reflection (for example, we have not proposed a discussion on the weighting of the fire/rules/growth dimensions). In particular, we must ensure that the women on the Cooperative Committee take more airtime in the deliberations.

Potential investors frequently want to verify our activities on the ground. This is totally understandable, given the significant investment involved, and we greatly appreciate these visits, which allow us to continually reassess the quality of our project.

In May, we welcomed consultants from Earthshot Labs, experts in assessing the compliance and integrity of nature-based carbon projects. The audit program was ambitious, as accompanied them to meet with communities in nine villages and assess tree growth on many many plots. At the same time, they analyzed in details all the data generated by our partners South Pole and EcoAct to compare this material with the reality on the ground.

Each interaction and observation generally raises new questions, increasingly specific and relevant, and the conclusion is always that nothing replaces a field visit.

On a 2022 plot of land in Borohila:

In Kofilakoro, just after the welcoming dance by the village women:

In Kofilakoro, closely supervised by the village children:

“Family photo” after the visit to the village’s sacred forest:

Peer group with the women of Tiegbenna, to address issues of discrimination and harassment;

Our forester, Seny Balamou, leads the discussion with the women and Ceci records the responses;

On a plot of land in the presence of its owner. The chief supervisor translates (he learned English in Ghana):

The women of Sokourala, proud of their seed harvest:

In Faranwandou, in front of the harvest of seeds ready for sowing:

A Faranwandou, devant la récolte des graines prêtes à être ensemencées.

In line with our commitment, we commissioned the Centre Interdisciplinaire de Recherche en Ethique (CIRE) at the University of Lausanne to take a critical look at our actions and identify areas for attention. We were impressed by CIRE’s interdisciplinary approach, which brings together expertise in environmental ethics, health, education and care. With its contextualised approach, CIRE seemed to us to be the institution most likely to help us make progress. We certainly think we’re doing the right things and doing them well, but there’s always room for improvement.

The CIRE report meets our expectations exactly. We are reassured that no new issues have been raised. And we are committed to finding solutions to the issues raised:

• We will be addressing the points of attention relating to carbon credits and the selection of investors to whom we sell them in subsequent news items.

• As far as the promotion of women is concerned, we are aware that there is still a lot to be done. From strengthening existing women’s groups to training young girls, not forgetting safeguarding the forestry knowledge held by the elders, the themes are many and varied. We also want to make better use of the skills of our partner GUIDRE, which has a perfect command of training courses for women (literacy, maternity care, prevention of female circumcision, etc.). During our last visit to Damaro, we met another NGO, a partner of GUIDRE, which supports the development of women’s market gardening, and with which we are looking forward to working. In short, the field of possibilities is almost infinite. It’s up to us to exploit it, within the framework of our statutes.

• The issue of remuneration for our seed-families will be addressed in June, when the first ‘carbon income’ is distributed in the Linko sub-prefecture. We will ensure that a proportion of this income is devoted to the seed-families and village communities. And this will be the subject of deliberations within the Cooperative Committee (made up, as you will recall, mostly of women). For the supervisors, our ambition is to secure their jobs as much as possible, at least for the three years of the plantation phase. After starting with 6-month contracts, then 10-month contracts, they now have 12-month contracts. We are now looking at ways of guaranteeing them real social benefits as well. From the outset, we have been paying amounts to deal with sickness and to finance their pension provision, but we would like to see accident/sickness insurance and pension funds managed by specialist bodies.

• The tension between free and informed consent and the social pressure linked to the constitution of the Cooperative is complex. The aim of all institutions for the governance of the commons, as suggested by Elinor Ostrom, is precisely to introduce rules, and therefore constraints, to better manage the commons. And it is true that this exerts social pressure. Where is the line between group pressure (and the benefits of joining forces) and coercion? How can we ensure that this social pressure is not exerted to the detriment of the weakest? On this question, deliberation, as recommended by the CIRE, is certainly the best way to highlight any grievances linked to ‘too much group pressure’.

In Linko, seed families become ‘measurers’. The three-year planting cycle came to an end in 2024 and it is no longer necessary to collect seeds to sow new plots at Linko. In order to maintain the link with the 370 seed families (mainly women), we have suggested that they take on a new and equally essential role, that of “measurers”.

Every year, it is vital to know the state of each of the 840 plots reforested since 2021. So it will be the scorers who will visit the plots to assess the growth of the trees and check that they are being properly cared for by the land families.

In each village, we have set up pairs of women measurers, who will be responsible for visiting 5 to 7 plots in a nearby village (to avoid any form of social pressure). In all, 187 pairs for the 840 plots in the project. Since 99% of the women (there are also men among the seed-families – and we have, of course, ensured that the pairs are not mixed) are illiterate, each pair will be accompanied by a local ‘guide’, from the Community Management Committees in each village, who knows how to use a smartphone.

In each of our 26 villages, our supervisors have identified a person who knows how to use a smartphone. These people were to be trained to use the QField geolocation application and to enter data in an online questionnaire. But when the training took place with the 26 people, we realised that not all of them had a smartphone… We had to buy 19 smartphones. Then we noticed that their use of smartphones was limited to making phone calls and watching videos… That’s just the way things are! In the end, only 5 out of the 26 could really act as guides for the measuring machines. So we had to find other guides (otherwise the 5 local guides would have had 75 days each). We recruited them from among the ISAV students who had come to do an internship on our project in 2023. Then we had to adapt the schedule to take account of the students’ obligations (graduation) and Ramadan (some husbands might have been reluctant to have their wives act as measurers during Lent).

The measurers started their visits at the beginning of April and finished at the beginning of May, just in time to prepare for the meeting of the cooperative committee before the General Meeting of the land families.

The 187 teams of measurers:

• Visited 703 plots of land
• Walked more than 650 kilometres in the plots of land
• Measured 13,278 project trees (under 5m) and 5,174 trees that already existed before the project (> 5m)
• Assessed each time: the impact of fires, the quality of land maintenance and the risks due to livestock.

It’s a high-quality piece of work for a first attempt. Congratulations, ladies and gentlemen! And thank you, because it allows the project and the family plots to know exactly which plots are well (or not so well) maintained and where the trees are growing well (or not so well). This makes it easy to provide targeted recommendations to each field-family to make the necessary corrections. And what’s more, this data corresponds to the satellite images!

“On International Women’s Rights Day, let’s celebrate the strength, resilience and beauty of all women! Happy Birthday to all the women of arboRise-Guidre! #8March”

Seny Balamou, silviculturist on the Linko-Damaro team

Our project would be nothing without all the women involved.

• …as seed harvesters,
• …as members of the Community Management Committees,
• …as village delegates on the Cooperative Committee,
• …as scorers,
• …as supervisors,
• …as foresters:

… multiple roles for multiple talents. THANK YOU ladies for your decisive actions!

A must-read for this March 8: L’autre langue des femmes, by Léonora Miano.

Diassodou, here we are !

The 2025 reforestation campaign has just begun, with three teams of five people in the field!

Remember that arboRise is currently active in two regions:

• In Linko – Damaro – Konsankoro (zone 1, marked in green below).
• In Samana – Diassodou&Karala – Sokourala – Koumandou (Zone 2, marked in blue below)

The plan for Zone 1 forsees the reforestation of 500 hectares per year. Spreading the efforts over several years made it possible to keep the required resources within reasonable limits. The disadvantage is that CO2 sequestration and thus carbon revenues are very low over many years.

For this reason, we have opted for a tighter schedule in Zone 2, with a second planting cycle starting one year after the first cycle. So, after starting the reforestation in the sub-prefecture of Samana in 2024, we will start the measures in the sub-prefecture of Diassodou in 2025.

As before the opening of each sub-prefecture, we also carried out a detailed analysis of the context in Diassodou: Human geography, protected areas, forest cover and eligibility, etc. This analysis allowed us to spread the effort of presenting the project over several groups of villages. The aim of our local partner GUIDRE’s team on the ground is to present the project to all villages in the region in order to convince 25 villages to participate in the project.

Here you can see the ‘family photo’ after the presentation of the project to the authorities of the Diassodou sub-prefecture:

The team then presents the project to all the village communities in the sub-prefecture, as here :

In the villages that quickly decide to join the project, the team finalises the agreements with the interested seed and land families. And the delimitation of the plots of land can take place.

As in Linko in spring 2024, we are also distributing individual and collective equipment in the sub-prefecture of Samana.

The mayor and sub-prefect of the rural district of Samana are of course involved in this event. The picture shows a harrow for the plough and, above all, a metal fence to protect the women’s market gardening areas from stray cattle.