Wild pines threaten native species such as the Araucaria and promote the spread of forest fires, among other problems. Social support is key to their control, but poor environmental literacy hinders conservation efforts.
The invasion of exotic trees, that is, the uncontrolled advance of tree species introduced by humans and left wild in natural areas, has grown globally, threatening not only local biodiversity, but also human well-being. South America is no exception: pines have acquired a special role in this part of the planet, including central and southern Chile. Although numerous studies address the ecological – and even economic – consequences of this problem, little research has been done on a determining aspect for its control, such as the role of society.
For this reason, scientists from the Institute of Ecology and Biodiversity (IEB), The University of Concepción and the Laboratory of Biological Invasions (LIB) analyzed the perception of tourists on the impact of invasive pines on the araucaria forests of the Malalcahuello National Reserve (Araucanía Region).The study, published in the prestigious Journal of Environmental Management, revealed visitors’ preference for aesthetic values and recreational interests, and a lower level of environmental awareness.
“The most important thing is that people who visit a natural area are not necessarily going to enjoy nature. Many are uninformed about the problems and threats to biodiversity. The good thing is that, with more environmental education, they can change their perception of the problem and become open to contributing to its solution,” he says. Aníbal Pauchard, IEB researcher and director of the Biological Invasions Laboratory of the Faculty of Forest Sciences at the University of Concepción.
Pine trees and a solitary araucaria in the background
The Malalcahuello Reserve is home to numerous species of flora and fauna, among which are the araucarias (Araucaria araucana, endangered),coigües, oaks, pumas, foxes and woodpeckers. The beauty of its landscapes attracts tourists from all over Chile, as well as from abroad, who come to do activities such as skiing, hiking, climbing the volcano and bird watching.
Valentina Bravo – Vargas, IEB researcher and lead author of the study, He points out that this “covers a small sample of the population, but it shows that in Chile environmental education is very basic, which is why there is a poor understanding of the problems and concepts. On social networks and in the media, they talk about environmental problems daily, and that is the information that people absorb. However, most people do not investigate on their own, and form opinions only based on what they hear.”
Researchers surveyed 138 people in the winter of 2015 and the same number in the summer of 2016. Of these, the majority were Chilean, representing 90% and 80% in the winter and summer seasons, respectively. When faced with six images of araucarias and pine trees, with and without snow, respondents preferred the landscapes without the exotic trees in both scenarios.
Also, a simple way to measure public support for invasive species control is the approach of willingness to pay (WTP). When they were asked about it, 46.5% of visitors expressed their willingness to pay for the control of pine trees in the reserve. However, the number increased to 79% after the surveyors gave a brief explanation about the effects that these invasive trees have on the Araucaria.
“It often happens that people answer what they think the interviewer wants to hear, but when the question is asked about a donation or financial contribution, they change their opinion because the question is no longer an assumption and involves their finances. No matter how small the monetary value, it is enough to demonstrate the commitment to wanting to help and to feel that they have made an effort to solve the problem,” explains the young scientist who graduated in Natural Resources Conservation Engineering with this research.
Participants who refused to contribute financially, even after the explanation of the effect of the pines, gave ethical, aesthetic reasons (such as “they are natural and beautiful elements”) and pragmatic reasons (“it is not my problem”).
As for the motivation to visit Malalcahuello in winter, 45% of respondents pointed to sports activities, such as skiing or snowboarding, followed by spending time with the family, while in summer the main reason was relaxation, family outings and sports such as hiking and trekking. Interestingly, “learning about nature” was rarely chosen in either season.
The researcher adds that “in many cases people were aware of the damage caused by pines, but they were still not able to differentiate them from araucarias at first glance, which reflects the lack of environmental education. This makes possible control measures difficult, since people are opposed to the felling of trees or ‘destruction of the ecosystem’, mainly because They do not distinguish between native and introduced species and they are not informed about what happens inside the reserve.”
Friends of fire
In the 1970s, the State established experimental plantations of four species of pine in Malalcahuello: Pinus contorta, P. sylvestris, P. ponderosa and Pseudotsuga menziesii. However, since they were never harvested for commercial purposes, the crops were abandoned. Currently, the most invasive tree in this protected area is Pinus contorta, native to North America.
The main areas affected by its spread have been the Araucaria and Notophagaceae forests, although its expansion to alpine vegetation and volcanic soil has also been reported. This is because pines reproduce – easily – beyond the site where they were planted, they compete with native trees for resources such as water and light, and they displace other types of plants native to these forests, preventing their development and also affecting the animals that depend on their existence.
On the other hand, the areas occupied by pines accumulate high fuel loads, which the risk of forest fires has increased. Pauchard explains that “as they grow, they increase the biomass, that is, the amount of branches, leaves and wood in the forest. In addition, they have very flammable resins. This creates a ‘recipe for disaster’, because this fuel dries out and can burn during the drought in the summer, causing the destruction of the araucaria trees in the area. The pine is naturally adapted to fire, so after a fire it will regenerate much faster than the araucaria.”
Another perspective of interest is The cultural relevance of the Araucaria for Chile and Argentina, especially for the indigenous Pehuenche communities (Pehuen = araucaria; che = people), which supply themselves, for example, with the piñón, the seed of this tree that has a high culinary, nutritional and identity value. For this reason, this charismatic species has been declared a Natural Monument and is recognized as the heritage of all Chileans.
Ultimately, this biological invasion represents a risk for the flora and fauna of the native forest, ecosystem services such as water production, and the tourism that takes place in the reserve due to the important natural, historical and scenic value of its landscape.
Experts reiterate the need to implement environmental education programs that, instead of focusing solely on the “natives versus invaders” struggle, raise awareness about biodiversity and the dangers it faces, cultural heritage and ecosystem services.
Bravo-Vargas stresses that “visitors can take an active role in species monitoring, by volunteering to conduct monitoring and dissemination activities, or by doing further research to subsequently make informed decisions. In any case, they should take importance in their role as people who enjoy the ecosystem services of protected areas, and help to protect them, trying not to worsen situations just because of ignorance.”
“Any intervention to control invasive species, whether plants or animals, requires the support of society, at local or national level. If people do not perceive invasive species as a problem, it will be difficult to be effective in managing them, and it may even lead to conflicts,” warns Pauchard.