Serra do Mar Coastal Forests

Category: Forest Biomes.

Geographic Location: South America.

Summary: The Serra do Mar coastal forests form a key part of Brazil’s critically threatened Atlantic Forest ecoregion. Very high species diversity and high rates of endemism make their conservation of paramount importance.

The Serra do Mar Coastal Forests biome stretches 1,500 miles (4,000 kilometers) along the coast of Brazil and also includes parts of Paraguay and Argentina. Moisture-laden clouds from the Atlantic Ocean keep the forest wet year round, and most tree species are evergreen. Largely a lush, tropical rainforest, Serra do Mar is referred to as part of the Atlantic Forest or Mata Atlântica. The climate is subtropical with a mean annual rainfall range of 55–157 inches (1,400–4,000 millimeters), and no dry season.

When Brazil was colonized in 1500, the Atlantic Forest was approximately 24.7 million acres (10 million hectares). At present, roughly just 5 percent of the original forest remains, all in isolated fragments and mostly in the Serra do Mar Coastal Forest itself. Although the majority of Brazilian cities, metropolitan areas, and about half the national population resides on the Atlantic coast, the forest has survived because the land, marked by steep terrain, is unfavorable for agricultural development. Currently only about 37 percent of the remaining forest is protected.

Despite its greatly diminished size, the Serra do Mar remains an eco-rich region containing numerous endemic (found nowhere else) species, many of which are threatened with extinction. In excess of half the tree species, and 92 percent of the amphibians, are endemic to this forest. Approximately 40 percent of Serra do Mar’s vascular plants, and as many as 60 percent of its vertebrates are endemic to the forest. More than 140 threatened terrestrial species common to Brazil are found in Atlantic Forest. Thirty-five of Paraguay’s threatened species take refuge here, and 22 of Argentina’s threatened species dwell in that country’s interior forest portion.

Biodiversity

New species are continually found here; in fact, more than 1,000 new flowering plants were discovered in the Serra do Mar between 1990 and 2006. Among the local plants are flowering Cassia (Cassia fistula); Tibouchina—a genus of about 350 species of neotropical plants in the Melastomataceae family—orchids (Orchidaceae); a family of monocot flowering plants called Bromeliaceae; many local varieties of the myrtle (Myrtaceae) family; and true laurel (Lauraceae).

The forest is divided into habitat types: the lowlands or coastal Atlantic forest, which comprises mainly tropical moist broadleaf forest; deciduous and semi-deciduous forest that extends across mountain foothills and slopes; and the forests in the cooler south, which are dominated by Parana pine (Araucaria angustifolia) or laurel. The Serra do Mar also encompasses mangrove forests, high-altitude grasslands or campo rupestre, coastal forests, and scrub on sandy soils, called restinga.

The Serra do Mar Forest biome is home to approximately 350 recorded bird species, and it is an important breeding ground for harpy eagle (Harpia harpyja), red-tailed Amazon (Amazona brasiliensis) and black-fronted piping guan (Pipile jacutinga), among many others.

Among the endemic mammal species are the endangered woolly monkey (Brachytelesarachnoides) and the critically endangered black-faced lion tamarin (Leontopithecus caissara). Many endemic species are so rare that their conservation status remains unknown, such as the officially data-deficient Ihering’s three-striped opossum (Monodelphis iheringi).

The Serra do Mar Coastal Forest biome also hosts populations of the endemic and critically endangered golden frog (Brachycephalus pernix), and a newly identified species of blonde capuchin (Cebus queirozi).

Other noteworthy species of the ecosystem include jaguar, ocelot, bush dog, La Plata otter, 20 bat species, and a number of endangered primates, notably muriqui and brown howler monkey.

Environmental Threats

The Serra do Mar Forest biome faces various environmental and ecological threats, among them deforestation, diseases that can impact wildlife populations, and climate change. Global warming effects in this part of South America are anticipated to include higher average rates of precipitation. The impacts are expected to result in heavier storms that will generate more frequent and severe floods and landslides, each of which can lead to fragmented habitat.

Deforestation in riparian zones has been shown to decrease the amphibian population in the Brazilian Atlantic Forest segment, and undoubtedly affects many other areas and taxa as well. If new, more lax forestry regulations are implemented, restoring deforested areas will no longer be required. However, there are private landowners restoring their own forests. Also impacting the forest are urban sprawl and its associated pollution and acid rain, as well as logging and poaching.

Bibliography

Becker, C. G. and K. R. Zamudio. “Tropical Amphibian Populations Experience Higher Disease Risk in Natural Habitats.” Proceedings of the National Academy of Sciences of the United States of America 108, no. 24 (2011).

Loyola, R. D., U. Kubota, G. A. B. da Fonseca, and T. M. Lewinsohn. “Key Neotropical Ecoregions for Conservation of Terrestrial Vertebrates.” Biodiversity and Conservation 18 (2009).

Morellato, L. P. C. and C. F. B. Haddad. “The Brazilian Atlantic Forest.” Biotropica 32, no. 4 (2000).

Olson, D. M. and E. Dinerstein. “The Global 200: Priority Ecoregions for Global Conservation.” Annals of the Missouri Botanical Garden 89, no. 2 (2002).

"Serra do Mar: Mountain Range System, State Park and Ecological Corridor (Brazil)." Latin America & Caribbean Geographic, 8 July 2020, lacgeo.com/serra-mar-mountain-range-system-brazil. Accessed 31 Aug. 2022.

Webb T. J., F. I. Woodward, L. Hannah, and K. J. Gaston. “Forest Cover–Rainfall Relationships in a Biodiversity Hotspot: The Atlantic Forest of Brazil.” Ecological Applications 15, no. 6 (2005).