Volunteers plant trees on the Kesra mountains in Tunisia's Siliana region.

Around 40 young Tunisian volunteers gather on a bare hill in the central region of Siliana. Their weekend mission -- revive a burned forest by planting Aleppo pine shoots.

Hamdi, from the eastern city of Sfax, gets straight to work after travelling 250 kilometres (150 miles) to the marginalised region.

A camping and hiking enthusiast, he found out about the initiative on Facebook.

Forest fires, both deliberate and accidental, eat away at hundreds of hectares each year.

"It's a chance to have fun and do something good together," says the student.

He is part of a network of nature lovers who have joined forces with Tunisian authorities for an ambitious venture; plant 12 million trees across the country by the end of this year.

That target equates to one tree per Tunisian citizen.

"We can only get there together," says Baya Khalfallah, one of the heads of the Soli&Green association, which launched the campaign in November.

Whether it's post-fire reforestation or fighting desertification in the south by planting palms and olive trees, the task is enormous.

Effective & enthusiastic

Soli&Green, founded by a handful of environmental activists in their thirties, organises planting weekends in winter and helps other organisations that want to do the same.

Since November, it has compiled a list of all the country's reforestation initiatives and estimates that by mid-January, almost a million trees had been planted.

The state does most of the work. The regional commission for agricultural development (CRDA), a public body, provides volunteers with basic training, thousands of tree shoots and a watering truck.

"When we use labourers, we plant around 1,000 trees a day. But with volunteers, we can plant 4,000, even 5,000 a day.

Soli&Green, founded by a handful of environmental activists in their thirties.

There are a lot of them, they are effective and it's free," says Nizar Khlif, a manager at the Siliana branch of the CRDA.

"And there is a participatory approach -- they involve the local population."

The arrival of the city-dwelling, backpack-carrying volunteers has inspired Siliana residents.

'Motivating'

"Before the fire, there was a dense forest here," says 46-year-old Khlifa Jaidi, pointing at a rocky hill.

Around 40 young Tunisian volunteers gather on a bare hill in the central region of Siliana.

Reforestation is a crucial part of curbing erosion and fighting global warming -- trees capture carbon dioxide, a greenhouse gas, and transform it into oxygen.

But it's also a way of creating local revenue.

"People used to gather Aleppo pine seeds to make zgougou (a traditional dessert) and rosemary, sold for its essential oil," adds Jaidi, a local guide from the nearby town of Kesra.

Forest fires, both deliberate and accidental, eat away at hundreds of hectares each year.

Reforestation is a crucial part of curbing erosion and fighting global warming.

But the state is increasingly joining forces with local residents and its reforestation strategies seem to be paying off.

Forests and scrubland now cover more than 1.3 million hectares (over 3 million acres), or around 8.5 percent of the country, up from 7.4 percent in 2011, according to the directorate general for forests.

The aim is to reach 10 percent by 2024.

Whether it's post-fire reforestation or fighting desertification in the south by planting palms and olive trees, the task is enormous.

The arrival of the city-dwelling, backpack-carrying volunteers has inspired Siliana residents.

Nessim Zouaoui, 26, says he is sometimes discouraged.

Agence France-Presse