Satellites reveal that only three forests remain intact on the Maule coast

Native forest on the coast of the Maule Region, where researchers identified only three fragments without signs of human intervention during the last four decades, of the 22 forest patches analyzed. These remnants are home to species such as the hualo and the queule and are located in a highly fragmented and threatened landscape.Dr. Álvaro Gutiérrez, academic at the Department of Environmental Sciences and Renewable Natural Resources of the Faculty of Agronomic Sciences. The fragments of intact native forest identified on the Maule coast have about 10 hectares and are inserted in a landscape dominated by forest monocultures. These patches have greater biomass, larger trees and greater species richness. Sebastián Landeros, engineer in renewable natural resources and author of the research, during field work carried out in fragments of native forest on the coast of the Maule Region. The study was developed within the framework of the Master in Territorial Management of Natural Resources of the Faculty of Agronomic Sciences of the University of Chile. RELATED LINKS • Detecting intact forests in a highly fragmented landscape: Complementary insights from Landsat and GEDI The coast of the Maule Region is a territory of high endemism and biodiversity. There, native forests inhabited by species such as the hualo and the queule are immersed in a highly fragmented landscape, where there are few remnants that have not been intervened in recent decades. This is demonstrated by a new study published in the scientific journal ISPRS Journal of Photogrammetry and Remote Sensing, which identified only three forest fragments without signs of human intervention during the last 40 years, out of a total of 22 patches analyzed in this area of central Chile. The research was developed by Sebastián Landeros, from the Faculty of Agronomic Sciences of the University of Chile and the Center for Climate and Resilience Science (CR2), and was supervised by academic Álvaro Gutiérrez, who also belongs to the Institute of Ecology and Biodiversity (IEB), and Mauricio Galleguillos, from the Pontificia Universidad Católica de Chile and CR2. The work was concentrated on the Maule coast, mainly in the Cauquenes area, where the Mediterranean forests are surrounded by a landscape dominated by forest plantations and subject to various threats, including the plantations themselves, forest fires, logging, drought and climate change. It is estimated that less than 20% of the planets forests would be without recent human intervention. A relevant question is to know where these remnants are and what surface area they occupy. In this context, we tried to map all the remnants of native forest that we could identify in this area of ??Chile and study their structure, considering as intact those without intervention in the last four decades, explains Álvaro Gutiérrez. To identify these fragments of native vegetation, the researchers combined information obtained through satellites with data collected directly on the ground. This strategy allowed not only to locate the forests, but also to reconstruct their history and characterize their structure. Sebastián Landeros, an engineer in renewable natural resources, points out that they first visited the remaining fragments of native forest in the basin, being able to verify that the majority have the hualo (Nothofagus glauca) as the dominant species. We also found very large oaks and very tall peumos in the intact forests. Some reached more than 20 meters in height. In the altered patches, on the other hand, we observed a greater introduction of exotic species, mainly pine and some eucalyptus. Álvaro Gutiérrez highlights that these intact patches are small, on the order of 10 hectares, and are inserted in a landscape dominated by forest monocultures of the exotic species pine insigne. “The native forest patches have a greater biomass, trees of larger diameter and height, and also a greater richness of species,” he says. Regarding the intervention of these forests, the clearest sign they found in the field was the presence of stumps, that is, the parts of the trunks that remain after a tree has been cut. Likewise, they found some pine trees in two of the three intact patches. Fortunately, they werent that spread out, but they were big trees. They were at least 20 years old and measured between 20 and 25 meters high, describes Landeros, who developed this study within the framework of the Masters Degree in Territorial Management of Natural Resources at the Faculty of Agricultural Sciences of Uchile, with the support of a scholarship awarded by the IEB. Looking at the forest from space To complement this information, the researchers used two technological Earth observation sensors. One of them was Landsat, a family of satellites developed through a joint program between NASA and the United States Geological Survey (USGS). His main contribution was to look back in time and reconstruct how the landscape had changed during the last decades. Landsat allows us to have a history of what had happened in the place during approximately the last 40 years. We used it mainly to diagnose whether the forest had been intervened during that period, for example, through deforestation or logging, explains Gutiérrez, a forestry engineer and doctor in Natural Sciences. The second tool was GEDI (Global Ecosystem Dynamics Investigation), a sensor that was launched into space at the end of 2018 and that uses pulses of laser light to measure the three-dimensional structure of forests, allowing us to obtain information such as the height of trees and the distribution of vegetation. Both Landsat and GEDI They generate information that is available to the scientific community, a particularly relevant milestone in countries like ours. The value of this information being openly available is enormous. One of the main problems we have in Chile, to understand the state of our forests, is our capacity to monitor,” comments the principal researcher at the IEB, a center that is funded by the National Research and Development Agency, ANID. With this background, Sebastián Landeros assures that one of the greatest contributions of this research was to demonstrate that satellite tools can be used to evaluate characteristics of forests and develop a workflow that allows distinguishing intact forests and that can serve as a guide to apply this technology in others. territories. The same results will not necessarily be obtained in all forests, because each territory has its own characteristics and difficulties, but a guideline can be established that allows continued research and monitoring of these ecosystems, he emphasizes. A landscape that needs protection Researchers warn that the Maule coast has a high value for conservation, but that the existing protection mechanisms do not necessarily ensure the effective preservation of all the remnants of native forest. On the Maule coast there are some reserves, such as the Los Ruiles National Reserve and the Los Ruiles National Reserve. Queules, but not necessarily all conservation figures ensure the same level of preservation. Therefore, it would be important to have mechanisms that allow these ecosystems to be effectively protected. In fact, the fact that we have only registered three intact remnants is quite serious, Gutiérrez emphasizes. Given this scenario, he suggests that the objective should not only be to conserve the three fragments identified as intact, but also the other 19 patches studied. Although these present different degrees of intervention and many are located on private lands, they are still part of a group. landscape of high biodiversity, where species that are in vulnerable conservation categories or in danger of extinction live. Among them are the naranjillo and the queule. This last species only grows on the Maule coast and its distribution has been considerably reduced. Added to this is the presence of species from temperate rainforests and sclerophyllous forests, which enter these environments and establish interactions with fauna and other species of trees, plants and bushes. These fragments not only affect the trees that make them up, but can also alter the relationships between species and generate greater loss of biodiversity. In this context, the authors of the study point out that the evidence obtained can contribute to improving public policies, provide information to land owners, help design mechanisms to protect these forests and be useful for the ecological restoration of this territory. Having this information is also crucial in the face of the threats that these ecosystems face, such as the expansion of invasive exotic species from the monocultures surrounding the forest. native forests, forest fires and logging - including the illegal extraction of wood to obtain firewood or produce charcoal -. Added to this are climate change and the intensification of drought conditions. Finally, Gutiérrez assures that it is a priority to improve the management of areas surrounding native forests, including fire prevention measures by the forestry industry, such as the use of firebreaks. The latter would be an important step to stop the degradation of this valuable natural heritage.