Ximena Herrera Alvarez, at UPNA.

As Ximena Herrera explains in her thesis, the Amazon region, with its 9 countries (Bolivia, Peru, Ecuador, Colombia, Venezuela, Guyana, Suriname, French Guiana, and Brazil), is the result of various geological, evolutionary, and human history processes spanning thousands of years. "It has been proven that the Amazon was domesticated by indigenous peoples approximately twelve thousand years ago, and many of the tree species present today are the result of this process.  Likewise, during the colonial and post-colonial periods, hundreds of years ago, tropical timber was first exploited for commercial purposes. Since then (1983), the trade of tropical timber has been regulated globally with exporting and importing countries, overseen by the International Tropical Timber Organization (ITTO). Specifically, Amazonian countries are considered exporters of tropical timber, with their main markets being China, the United States, and some other countries in the European Union," she explains.

However, although tropical timber has had certain known characteristics, "an international definition of Amazonian tropical timber species has not been proposed by the relevant international organisations, nor have the ecological attributes that enable a tropical tree species to be considered timber-producing by the nine mentioned nations been analysed.”

Review of concepts and databases

In the thesis, a systematic review of the concept of timber species was first conducted, comparing the data with the concepts put forward by the international organisations ITTO and FAO, as well as the responses from a survey carried out in the mentioned countries regarding the characteristics or criteria their forestry institutions consider for a species to be classified as timber species.

Secondly, a database called MADERA was created, standardising the scientific names of timber species from the nine Amazonian countries (1,136 tree species). This database also included information on population, hyperdominance, IUCN (International Union for Conservation of Nature) conservation categories, trade, and the vulnerability of these species in scenarios of climate change and deforestation.

Thirdly, another database of Amazonian trees was created based on their taxonomy, standardised for a total of 6,457 tree species. This database also incorporated certain information from the MADERA database, as well as ecological variable data from 846 one-hectare plots belonging to the permanent ForestPlots monitoring network (University of Leeds), along with additional complementary information from the Amazon Tree Diversity Network (Netherlands).

Finally, the analysis of these data allowed for the first time an understanding of the ecological attributes that enable a tropical tree species to be considered “timber species” by the aforementioned countries. In this regard, “one of the main contributions of this thesis is the proposal of a preliminary concept of Amazonian tropical timber species, which includes the following findings: they are abundant or hyperdominant, locally frequent, and have large individual biomass. These species are found in all types of forests, but mainly in terra firme and swamp forests. Moreover, these species often have many uses beyond timber exploitation, and therefore may have a wide range of wood densities,” points out the thesis author.

However, as Ximena Herrera notes, this definition of Amazonian timber species must be evaluated by the responsible international organisations, primarily to prevent the extraction of wood from threatened species and those for which insufficient data is available. Another threat to these species is the droughts the Amazon region has suffered in recent years. “I urge international organisations to promote well-defined criteria and indicators at regional and national levels, which have been previously evaluated by the scientific community, to be applied in each country. Then, they should list the species that would be authorised for subsistence use by local and indigenous communities, as well as in the timber industry. It is imperative to consider the landscape approach of the entire Amazon and the potential tipping point scenario due to climate change and deforestation in this biome,” concludes the thesis author.

The research has been funded by UPNA and Government of Navarre, and has also involved the collaboration of several researchers from the Amazonian tropics, including Oliver L. Phillips (University of Leeds, UK), Hans ter Steege (Naturalis Biodiversity Center, Netherlands), Leonardo Ortega – López (Universidad Regional Amazónica Ikiam, Ecuador), Martin Sullivan (Manchester Metropolitan University, UK), Vicente Guadalupe (BioAmazonía project of the Amazon Cooperation Treaty Organisation with its member countries).

Brief CV of Ximena Herrera

Ximena Herrera Alvarez has a degree in Applied Ecology from University San Francisco de Quito (Ecuador) and later studied the Master’s degree in Environmental Agrobiology taught at Public University of Navarre (UPNA) and University of the Basque Country. The results of her doctoral thesis have been published in the journal “Ecology”, one of the most prestigious international journals in its field, and have been presented at various international conferences.

She has participated in several ecology projects in different ecosystems, and her research focuses primarily on the dynamics of tropical forests and temperate forests after disturbances such as selective logging or wildfires, among others, as well as in different altitudinal gradients.

She is interested in a better understanding of forests so that their use does not pose a risk to the functioning of ecosystems. Similarly, she is keen on connecting science with its application through the responsible international organisations and society.