Small groups, large forests

Farmers use handheld computers and GPS to map tree planting progress

Ben Henneke

Farmers working with the International Small Group and Tree Planting Program have been using handheld computers and portable GPS receivers since 1999 to collect data for carbon credit trading. In that time, the project has planted more than twenty million trees in six countries.

Over the last twelve years, farmers in the Mpwapwa district of Tanzania have transformed their drought-prone land into an area where crops grow in the shelter of recently planted trees. Although the region was covered with dense forest little more than 100 years ago, the trees were cut down to make way for more agricultural land, and to provide material for housing and firewood. The rich but fragile soil, typical of forest regions, eroded rapidly in the arid climate. The people living there struggled to produce enough food from the land, leaving them to rely on food aid in the very worst years.

In 1999, however, the communities were the first to become involved in a pilot project to grow trees in the area, and investigate ways to increase their income through the carbon trading mechanisms outlined in the 1997 Kyoto Protocol. The International Small Group and Tree Planting Program, also known as TIST, supported farmers to reintroduce trees to their farms. Extra tree cover would help to protect the soil from further degradation, encourage grass to grow, provide shade and windbreak for crops and, depending on the tree type, supply fodder for livestock.

The farmers benefitted relatively quickly from the improvements to the land, but they knew that it would be a long time before they saw any significant return from any carbon trading scheme. To qualify for such awards, the groups first had to collect data to indicate what the land looked like before the tree planting began. The carbon credits could only be calculated in the future if the communities already had a baseline to show that any new tree growth was additional to what had already been there.

In order to do this, they had to produce detailed maps of the land they intended to develop, and provide accurate estimates of the existing vegetation. The communities had to record a wide range of data, including the exact coordinates of tree groves in the area, accurately calculate their size, and then make all that data available for the inspection and evaluation.

‘We knew we needed a high quality data collection system,’ says Ben Henneke, co-founder of TIST, ‘even though we didn’t have qualified people to gather the data or analyse it.’


At the time, the town of Mpwapwa had only three antique telephones, and no reliable electricity supply. It was clear that the groups would have to rely on battery-powered devices to gather and record their data on the farms, but even a laptop computer would consume too much energy to be practical. The only alternative was to use handheld computers. Those manufactured by Palm were found to be suitable as they could last three weeks with rechargeable batteries.

The long battery life meant that the farmers could travel back to their villages to collect data, and only have to return a few weeks later to synchronise the information with a laptop computer. TIST has no project vehicles in any of the participating countries, so the data collection process has to fit in with the usual travel routines of the people involved.

TIST had to develop the database capabilities of the Palm computers to accommodate the many types of data they needed to collect. The team also wrote a program to accept input from a handheld GPS receiver, to add location coordinates to the information on the database.

Over the years, however, as the Palm computers became more sophisticated, they also presented a problem. The new colour screens used more energy, and the batteries lasted only a fraction of the time. The team had to use backup flash drives for the devices to protect all the data if the power ran out.

One important development was when Palm upgraded their devices to include a camera. Although photographs are not required for any carbon trading system, Henneke stresses their importance for other reasons. ‘Photographs give a ground view of the young trees growing,’ he says. ‘They provide another layer of proof to investors around the world, especially those who invest directly from our website, that these trees are actually being planted. Anyone can visit the website to follow the progress, and see the farmers and where they live. The photos add that personal element.’

Investors can view the photos on Google Earth too, to see the exact locations of the trees that TIST groups have planted, and even find the homes of the farmers. The interactive element, says Henneke, provides people with yet another way to learn more about the project, see the change in the landscape over time and visualise the work of the groups.

The technology makes it possible to carry out hundreds of accurate surveys a week without having to pay expensive professionals


Since 1999, and with the support of USAID, TIST has expanded to work with more than 60,000 farmers in Tanzania, Uganda, Kenya, Honduras, Nicaragua and India. The programme was only possible, says Henneke, because of the battery-operated handheld computers and portable GPS units. ‘It would have been impossible to record the amount of data with the degree of accuracy we require using pen and paper alone,’ he says. ‘We could not have kept detailed paper records on the progress of tens of thousands of smallholder farms. It’s certainly possible to record the survey of a large forest on paper, but we couldn’t afford professional surveyors every time we wanted to collect data.’

The income from tree planting is still minimal for the TIST farmers. They continue with subsistence farming and have less time for data collection, for example, when the rains come and they have to prepare their land. But the programme is set up so that they do not have to work full time gathering tree data; only when they have the chance.

‘The technology makes it possible for us to carry out hundreds of accurate surveys a week without having to pay expensive professionals,’ says Henneke. ‘We don’t even need a surveyor to teach the farmers how to gather the data.’

Collecting accurate and detailed information is vital for participation in any carbon trading scheme. TIST, therefore, trains a number of people from the groups to collect the data. These ‘quantifiers’ are often young people from the communities who all attend seminars in their countries to ensure that they collect the data using consistent methodologies. Standards are maintained throughout the programme as quantifiers from one country train those from another. Tanzanian quantifiers, for example, helped to train new quantifiers when the project expanded to Kenya.

TIST also trains auditors, who regularly check the data through random sampling. Quantifiers whose data is found to be accurate within a 5% margin of error receive a bonus, but those who are inaccurate by more than 10% are suspended. This might seem strict, but as Henneke explains, the whole operation depends on the quality of the data. On his frequent visits to the tree planting sites, he also double checks the findings of the auditors. Their work is then also subjected to further validation by a third party.

Peer education

The small group aspect of TIST’s work is, adds Henneke, essential to the efficient, and cost-effective, operation of the project. The technology, specifically using handheld devices, ensured that TIST could keep the organisational structure simple, limiting management and administration costs and reducing bureaucracy. Such a basic formation also means that other smallholder farmers can easily replicate the system to set up and run their own tree planting group.

Groups from the same area are encouraged to meet once a month, in order to discuss sustainable agricultural practices. Community members get a chance to refresh their skills, and many travel to other groups to learn and share ideas. These occasions also provide an opportunity to exchange information on other issues affecting the community, including health advice, and they have even been used to distribute bed nets for malaria prevention.

TIST often invites farmers who prove to be particularly active in their groups to larger seminars to learn new techniques and meet others involved with the programme who are working in different areas or even other countries. ‘Our assumption for these seminars,’ explains Henneke, ‘is that there is enough information in that room to solve almost all the problems anybody has. Increasingly though, the farmers take these opportunities to search the internet for further details.’

Even in the introductory seminars, when communities first learn about the programme, TIST does not provide them with large amounts of information and opinions. Instead, the team facilitates the discussion about deforestation, farming, land degradation and soil erosion. Henneke admits that many farmers are sceptical about how they will fit all the extra work into their busy lives, especially when they hear that they will not earn much money to compensate them for the time not spent on their farms. Through sharing their own experiences, it quickly becomes clear that the environmental damage and reduced crop yields have occurred mainly as a result of cutting down trees.

‘The farmers discuss the effects on their own land, and realise that the problems they face are common to more people,’ says Henneke. ‘They realise that the practices they learned from their parents and grandparents are not sustainable as the land is subjected to increased pressure. It is at this moment that they start asking how TIST can help. At the end of these small group discussions, they leave the seminar as committed farmer-environmentalists.’

Each community then decides how they are going to organise the programme in their area. Since local conditions vary widely, TIST cannot produce a single plan of tasks with a list of who should do what and when. The only stipulation TIST makes is that there should only be six to twelve people in each small group, they meet regularly, and they report accurately.

‘Many other projects work in small groups of maybe 50 people,’ says Henneke, ‘and they often have power structures which are permanent, or certainly long-term. Those who are not in power find it difficult to have any influence. In these very small groups working with TIST, there is no need for a permanent chairperson, secretary or treasurer. Instead, the leadership rotates, either every week or every month, that’s up to the group.’

Trust in technology

It takes five to eight years before new trees are big enough for their carbon to be counted in a carbon trading system. In the meantime, however, TIST pays them a small annual premium per tree once the trees are planted in the ground (i.e. not in the nursery) and pays for organisational and monitoring costs.

When those trees are included in a carbon credit transaction, 70% of the profits go directly to the farmers. The other 30% goes towards expansion, repaying the premium payments, and the funds already invested to set up and operate the programme to date. Sharing the profits gives everyone involved a common desire to keep the costs low.

TIST still uses the Palm handheld computer throughout its project sites, and they try to keep costs low by buying second hand equipment. Some quantifiers use the Treo or Centro models, smartphones that have the advantage of being able to send data over the cell phone network. Remote synchronisation saves the quantifiers a lot of time that would otherwise be spent travelling to internet cafes, or another site with an internet connection. Many quantifiers prefer even earlier Palm models that have a bigger screen and where they can enter the data using a stylus. The process is quicker than using a small smartphone touch screen or keypad.

The team have tested other GPS-enabled smartphones, but their database capabilities do not yet match the organisation’s data collection needs. Also, they found that the GPS reception is not as reliable as many stand-alone GPS receivers, and therefore does not provide the necessary accuracy.

Henneke is quick to point out that, although the technology has been invaluable to the programme, it was not strictly necessary for the improvements to the land. ‘The environmental change comes from the new trees,’ he says, ‘the technology simply helps us prove that the trees were planted, and that they are still growing. But the high-quality data is important. That’s what people invest in and that’s what brings money back to the farmers.’

Henneke adds: ‘If we could only find some other way to convince sceptical investors and governments that these trees actually exist, then the farmers would be able to save a lot of time and money, and could invest much more in the land. If we could solve that problem, even more farmers would become involved, and we would be able to plant even more trees.’


Ben Henneke is co-founder of the International Small Group and Tree Planting Program, and president of the Clean Air Action Corporation .


Buy carbon credits directly from the International Small Group and Tree Planting Program website from US$ 10 per tonne.

26 April 2011

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