Universidade Federal de Santa Catarina

The abundance of water and the richness of species in the forest in the Distrito do Saí reinforce what researchers at the Universidade Federal de Santa Catarina have already recognized from the literature and other works in the locality: it is necessary to promote the conservation of the biodiversity and enhance sustainable tourism in the region. The creation of a Wildlife Refuge will allow the Atlantic Forest to remain protected, which also guarantees quality water and other benefits to the communities.

“Ensuring the preservation of the forest plays an important role in connecting people with nature, in entering the forest and feeling comfortable. The forest promotes a very pleasant sensation: thermal, aesthetic sensation, of walking into a forest and being able to see flowers, birds, insects. Since this type of tourism is more focused on enjoying the environment, it is important that the forest is very well preserved”, explains Professor Pedro Fiaschi, from the Botany department.

The forest in the Distrito do Saí, according to Fiaschi, has characteristics that attract attention. The area is covered by Atlantic Forest in an advanced stage of regeneration. “In this region we have tall trees with a large diameter, in addition to structuring at various levels: from very large trees to the lower layers. There are several forest extracts showing signs that they are in an advanced state of regeneration”, he explains. In addition, there are also sections that can be primary forests – that is, that have never been impacted and that have preserved their original characteristics even before the arrival of the human species.

According to the 2020 report by SOS Mata Atlântica, this biome covers about 15% of the Brazilian territory, which is equivalent to 17 states. Furthermore, it is home to 72% of the population, housing three of the largest urban centers on the South American continent. Data on its deforestation also draw attention: from 2018 to 2019, 14,502 hectares – or 14,000 soccer fields were suppressed, threatening its rich biodiversity.

In the Distrito do Saí, however, the report by the UFSC researchers indicates a relatively preserved area, which increases the relevance of conservation measures. According to the professor, many areas of the Atlantic Forest were impacted by human action during the urban occupation process, which is less evident in the Saí region. “All of this suggests that this region should be preserved. A very well-preserved forest will have a much larger number of species and will also be home to many species of animals. The more species there are in the flora, the richer the associated fauna will be”.

These evidences, however, do not suggest that there were no impacts of human action on the native forest. According to the researcher, it is possible that there has been, in the locality, a history of clear-cutting in some sections, with the removal of the forest, and also the selective removal of some species, such as jequetibá and ocotea catharinensis, popularly referred to as “canela-preta”. Thus, even though the forest is considered to be at an advanced stage of regeneration and is rich in species, there are other regions, even in Santa Catarina, which are in a better state of conservation, especially those located in steeper regions, where access to human action is hampered.

Floristic richness

The jequetibá is a tree with a broad, large and showy trunk,  those that are impossible to miss. Therefore, it is difficult for them to go unnoticed even by lay eyes. In the field work at UFSC, a student of Professor Pedro Fiaschi identified a young specimen. “He collected a branch and showed it to us. It is possible that there are more in the forest, but this one we identified is a young one”, he explains. The species is considered endangered, but it can be found in the Distrito do Saí.

According to the professor, this species is not found in other regions of the state. In Florianópolis, for example, there is no record of jequetibás. This happens because the forests further north, in the Atlantic Forest, usually have records of species that do not occur in areas further south of the state. The Distrito do Saí, therefore, has this differential: being on the North Coast, it will have some species characteristic of a region with more abundant rainfall and a slightly less seasonal climate than that of Florianópolis, for example. This was one of the points highlighted by the team that carried out the survey in the project report: the forests of the Distrito do Saí are characterized as important floristic components of the state because of this characteristic, “contributing to the biological richness of Santa Catarina and providing habitat for a wildlife equally biodiverse”, as stated in the report.

For researchers, the existence of many species of bromeliads, ferns and other epiphytes in the Distrito do Saí is not surprising. These species are common in the Atlantic Forest and many are not found in other Brazilian biomes.”About bromeliads, when you go to a forest and look up at the trees, you can see many species growing on the trunks of trees, which is not surprising in well-structured forests located on hills, with large trees and light penetration from several angles”, he summarizes.

According to the professor, the beauty of these plants can be an attraction for tourists, as they also attract many species of birds and other pollinators. “Like many other plants, bromeliads have a lot of interaction with pollinators, which are very important for their reproduction, while other plants depend on animals to disperse their seeds, which is essential for the maintenance of the forest, as it allows repopulation from other areas”.

Ferns also appear as part of the project report. Some species are rarer and known in a few places. “In the Distrito do Saí we identified many species of fern, much more than we would find in Florianópolis, for example. They are a group that are associated with rainforests and generally occur where there are many bodies of water and rain well distributed throughout the year”, he explains.

The forest formation, therefore, stands out in the landscape of the Distrito do Saí. According to a survey by Professor Orlando Ferretti’s team, more than 90% of the soil in the studied region has this composition – and only 1.14% would be exotic, planted forest. “We already imagined that the Distrito is a very important region in terms of biodiversity. Of course, within it there are areas that have undergone recent changes, due to occupations that are more on its margins. In fact, the area surrounding the conservation unit registers that the urban occupation is reaching the polygon”, he explains.

This biodiversity, according to the professor, is also attributed to the formations of the Serra do Mar, a mountain range made up of numerous reserves. The vegetation in the region, he explains, was transformed at least 50 years ago, with selective cutting in some places. “Even so, we realize that it is in a very interesting state of regeneration, with hilltops and slopes that have recovered well, which also provides good quality to the region’s water, in more than 150 spring points”.

Water

The forest’s relationship with water also says a lot about the quality of both. According to the 2020 report by the NGO SOS Mata Atlântica, the biome provides water for more than 60% of the Brazilian population. It is no different in the North Coast of Santa Catarina and particularly in São Francisco do Sul. The name of the UFSC project, Nascentes do Saí, refers to the region’s hydrological characteristics.

According to Professor Nei Kavaguichi Leite, from the Department of Ecology and Zoology, it is possible to use the water cycle to understand the role of the forest in relation to this aspect. One of the illustrative images of the phenomenon is when part of the rainwater is retained in the crown of trees, which causes the soil to absorb it more slowly, recharging aquifers that feed the rivers. The lack of forest cover, on the other hand, accelerates this process and causes the soil to quickly become saturated with water. “This generates a high surface runoff that can lead to a rapid increase in the level of rivers and streams, with consequent flooding, or even result in siltation due to the input of large amounts of sediment in water courses.”

Conserving the forest ensures water quality

The study by the project’s hydrology team covered nine hydrographic basins, with an interest in understanding water availability in these areas, also verifying its distribution and abundance. Another important point to be considered is that these waters are responsible for part of the supply of the municipalities of São Francisco do Sul and Itapoá, ensuring quality of life for the population. Five of the eight water catchment points of the company Águas de São Francisco are in the region.

According to the report, the analyzed hydrographic basins have an area of approximately 26.7 km2, with monitoring carried out by the hydrology team covering approximately 77% of the study area, in an approximate total of 57 springs. Springs are the point where a watercourse begins and are located in the highest regions.

The water abundance in the Distrito do Saí was also corroborated by the highrate of  rainfall, with an annual average of 2,363 mm, above that recorded in Santa Catarina, which is 1,506 mm. The analysis also highlighted the extensive coverage of native forest, which ensures the urgency of conservation measures. “There are streams that are in regions with a certain degree of anthropization, but a very relevant aspect is the maintenance of riparian forests, which border the rivers. These are forests that serve as a refuge for biodiversity, guarantee the stability of the ravines and control the water that reaches the streams. In many of these streams that we studied, riparian forests provide food for many species and also serve as recreation”, points out Nei.

The professor also recalls that the maintenance of these woods and the forest, in general, are also preventive measures for landslides caused by the heavy rainfall. “The lack of vegetation cover can lead to erosion and even siltation of streams. In places with small changes, such as the fall of a tree, at some point, this phenomenon is already detected. Completely changing the characteristics of the region can generate a very big impact”, he ponders.

The alert also comes from Professor Orlando Ferretti. According to him, despite the great biodiversity and the large amount of forests, the area presents risks of landslides if the forest is not preserved and does not become the target of environmental policies. “When you see the type of soil that exists there, susceptible to geological risks, and also the amount of rain, one can even speak of a more immediate risk, since the urban area is growing”.

Read more this Thursday, 09/30

Amanda Miranda/Agecom Journalist

Translated by SINTER/UFSC

Read the original article here