Inauguration Marielos Peña Claros: Managing tropical forest to conserve them

September 22, 2022

“Tropical forests are important at local, regional and global scales, and we need to conserve them,” says Marielos Peña Claros, personal professor at the Forest Ecology and Forest Management chair group (FEM) since 2019. On 22 September, she will deliver her inaugural address.

prof.dr. Marielos Pena Claros
prof.dr. Marielos Pena Claros

Tropical forests are important at local, regional and global scales. Locally tropical forests are essential for millions of people, who rely on all kinds of forest resources like fruits, nuts and timber for their daily subsistence. Regionally tropical forests, like the Amazon forest, play an important role in supporting rainfall for the whole region. Globally tropical forests are important for biodiversity and for climate change mitigation. “But deforestation rates in the Amazon are still high, and unfortunately, forest degradation is also management a serious problem”, says Peña Claros.


“One of the options to conserve tropical forests is sustainable forest management”, Peña Claros indicates. The idea behind sustainable forest management is that forest products, such as timber, nuts, fruits, and leaves can be harvested sustainably, generating income for local people and the country without reducing forest cover and without decreasing the provision of ecosystem services for future generations.

Reducing damage to the forest

One of the main products extracted from tropical forests is timber. “Timber extraction in the tropics is selective, as only a few species have commercial value. This means that only a few trees per hectare are extracted”, she explains. But timber extraction can be harmful if not done correctly. “There have been quite some efforts to come up with techniques that reduce the damage during timber extraction”, she mentions.

This starts with doing a full inventory of the forest to know precisely where trees are located. “Then, forest managers can make a better plan to harvest the same amount of timber with the least amount of trails to open. This reduces damage and also costs,” she says. But research shows that this is not enough in the long term.

Accelerating the recovery of trees

“Using data from the Tropical managed Forest Observatory network, we have shown that in general low extraction levels and a long period of time are needed to recover the same amount of timber as extracted the first time”, she explains. In the coming years, Peña Claros wants to study how the recovery rate of timber volume can be accelerated. “We think that it helps to create optimal growing conditions.

For example, trees covered with lianas grow much slower than trees without lianas”, she explains. “So by removing the lianas growing on trees to be harvested in the future, competition for light and water is reduced, and the trees can grow faster”. In that way, timber volume recovery is likely to be faster. “The first results are promising, but we do not know the long-term effects of such practices, nor how the effect varies with soil and climate.”

Societal impact

While much attention is paid to reforestation, Peña Claros believes it would be better to focus on preventing deforestation or forest degradation. Her mission also drives her to take action in the Netherlands. “Last year, it became clear that our pension fund ABP still invests in companies that are linked to deforestation in the Amazon. I cannot reconcile this with what I stand for as a researcher working on the conservation of tropical forests.”

“So, together with colleagues from the Forest and Nature Conservation Policy group, we collected signatures among WUR-researchers and defined a way to reach out to ABP with the Executive Board. We have had some good discussions with ABP, and hopefully, these discussions will lead to changes in their investment policy.” Also, in the future, Peña Claros feels it is her responsibility to ensure that this topic stays on the agenda, in science and society. “Our planet needs it.”