The least known biomes of Brazil

Brazil is one of the richest country of the world in terms of biodiversity. The Amazon rainforest, often known as the world’s lungs, is recognized as the world’s most diverse region. Is it really so? Brazil hides many more biomes as richer as the tropical rainforest, but much more unknown and with a high degree of threates that affect its conservation. In this post I will explain the main characteristics of the six Brazil biomes and I will review different crops that have been introduced into the country since historical times affecting the natural balance of its ecosystems, from sugar and coffee to soybeans.

WHAT IS A BIOME?

In this post I will discuss the different biomes of Brazil. But what is a biome? It is a group of ecosystem with a common history and climate and therefore being characterized by the same animals and plants. Biome concept includes all living beings of a community but in practice biomes are defined by the vegetation general appearance. Is a unit of biological classification used to classify major geographic regions of the world. Thera are ten recognized biomes in the world: polar desert, tundra, taiga, temperate deciduous forest, laurel forest, rainforest, steppe, savannah, desert and Mediterranean.

BIOLOGY OF BRAZIL

Brazil is recognized as the country with largest biodiversity in the world, followed by China, Indonesia, Mexico and South Africa. Brazil, according to recent scientific publications, is the country with the richest flora in the world, with 46,100 species of plants, fungi and algae described, 43% of them being endemic. This number increases every year since many Brazil biodiversity is still unknown. In fact it is estimated that 20,000 species have not been described yet. Botanists describe about 250 new species of plants every year in Brazil. So if you are taxonomist willing to contribute, there’s people lacking in Brazil!

Another amazing fact is that, 57% of the 8900 seed plant species in Brazil are endemic.

BRAZILIAN BIOMES

Nowadays, six different types of biomes are defined in Brazil: Amazon, Atlantic Forest, Cerrado, Caatinga, Pampa and Pantanal. This classification has little changed since the first attempt to classify the Brazilian vegetation in floristic domains elaborated by Martius in 1824, who gave names of Greek nymphs to the five domains detected. He chose the Nayades, nymphs of lakes, rivers and fountains to call the Amazon. For the cerrado, he took the Oreades, nymphs of the mountains, companions of Diana, the hunt Goddess. He named the Atlantic forest under the Dryades, the nymphs protective of oaks and trees in general. He considered pampas and araucarias forests under the Napeias dominion, nymphs of valleys and meadows and finally Hamadryades, nymphs protectors each one of a particular tree, were used to designate the caatinga.

Brazil is one of the few countries in the world including  two hotspots for the conservation of biodiversity: the Atlantic Forest and the Cerrado.

Cattinga in the only biome exclusive from Brazil, tough other Cerrado-like savannahs are found in South America and the Atlnatic Forest, out from Brazil, is only found in North-East Argentina and East Paraguay.

Map with the distribution of the six brazilian biomes.

1. AMAZON

The Amazon basin area is the world’s largest forest and the most biodiverse biome in Brazil. It occupies almost 50% of the country and is seriously threatened due to the deforestation caused by logging industries and soybean crops. Currently it is estimated that 16% of the amazon rainforest is under anthropic pressure.

Aerial view of the Amazon rainforest (Source: Commons Wikimedia).

The origin of the Amazon diversity remains a mystery. Recent scientific studies explain that the rise of the Andes, which began at least 34 million years ago originated this biological richness. The Andes were formed by the collapse of the American tectonic plate under the Pacific oceanic plate. This geological process changed the wind regime in the area, affecting the rainfall patterns in the eastern side of the Andes. This also changed the Amazon River direction that before flew into the Pacific Ocean but due to this gemountain range rise was redirected to the Atlantic ocean.

These geological and climatic phenomena originated the formation of a large area of wetlands in the eastern part of the Andes, causing the appearance of many new species. The Amazon is an enclosed tropical rain forest with a sandy soil, poor in nutrients. The undergrowth is nonexistent and organisms are distributed along the canopy.

We found pantropical plant families like Fabaceae, Rubiaceae or Orchidaceae, and other of Amazonian origin; as Lecythidaceae (one of its most famous species is the Brazil nut tree, Bertholletia excelsa) or Vochysiaceae.

Bertholletia excelsa, the Brazil nut producer, typical from the Amazon rainforest (Source: Flickr and Commons Wikimedia).

2. ATLANTIC FOREST

Atlantic forest is a tropical forest covering the coastal region of Brazil and therefore it is characterized by humid winds coming from the sea and steep reliefs. It is composed of a variety of ecosystems because a high variety of altitudes, latitudes and therefore, climates ranging from semideciduous seasonal forests to open mountain fields and Araucaria’s forests in the south.

Araucaria forest, ecoregion considered in the  Atlantic forest domain in south Brazil (Source: Wikipedia).

 Although much more less known than the Amazon rainforest, the Atlantic forest has the largest diversity of angiosperms, pteridophytes and fungi in the country; with a very high level of endemism (50% of its species are exclusive) and is in a worst level of conservation. In fact until the arrival of the Europeans, it was the largest tropical forest worldwide. Today remains only 10% of its original length due to anthropogenic pressure. One of the first exploitation of this biome was the pau-brasil (Caesalpinia echinata), valued because of its wood and the red dye of its resin, that gave name to the country. Pau-Brasil was then followed by others human impacts as sugar cane and coffee cultivation and gold mining. But it was not until the twentieth century that the degradation of the environment worsened, given that the major economic and historical capitals like Sao Paulo, Rio de Janeiro and Salvador are within its domain.

Typical landscape of the Atlanic rainforest (Source: Commons Wikimedia).

However, we must be optimistic. The Atlantic Forest biome is the region with more conservation units in South America.

3. CERRADO

It is the second largest biome of South American covering 22% of Brazil.

It is considered the richest savannah in the world in terms of species number. It contains a high level of endemic species and it is considered one of the global hotspots in terms of biodiversity. Containing 11,627 species of plants (of which 40% are endemic) and 200 animal species, 137 of which are threatened to extinction.

Cerrado is in interior areas of Brazil with two well marked seasons (rain and dry season). It includes different types of habitats such as campo sujo, campo limpo or  cerradão. It is composed of small trees with deep roots and leaves with trichomes and an undergrowth composed of sedges and grasses. Cerrado soils are sandy and nutrient-poor with reddish colors featuring the high iron content.

Typical landscape of the Cerrado (Source: pixabay).

Vochysia and Qualea (Vochysiaceae) genera dominate the savannah landscape of the cerrado. Representatives of the Asteraceae, Fabaceae and Orchidaceae are the most frequent in terms of species number.

It is in second position in terms of degradation in Brazil recent decades. The origin of this destruction is the development of the agricultural industry: approximately 40% of soybean crops (Brazil is the largest producer of soybeans in the world) and 70% of beef are produced in cerrado areas. Half of the cerrado biome has been destroyed in only the past 50 years. Despite this risk only 8% of its area is legally protected.

Soybean monoculture inside the cerrado domain in Tocantins (Source: barres fotonatura).

4. CAATINGA

It is the only exclusively Brazilian biome and occupies 11% of the country. Its name comes from a native language of Brazil, the Tupi-Guarani and means white forest. However, this biome is the most undervalued and little known because of its aridity.

The climate of the caatinga is semi arid and soils are stony. The vegetation is steppe and savannah like and is characterized by a great adaptation to aridity (xerophyte vegetation) often prickly. The caatinga trees lose their leaves during dry season, leaving a landscape full of whitish trunks.

Typical landscape of the Caatinga (Source: Commons Wikimedia).

Plant families predominating caatinga landscape are Cactaceae (Cereus, Melocactus or Pilosocereus genera are common), Bromeliaceae and Euphorbiaceae, but representatives from Asteraceae, Malvaceae and Poaceae can also been found. A typical native caatinga species is Juazeiro (Ziziphus joazeiro, Rhamnaceae).

Melocactus sp. (Cactaceae), a very comon genus in the caatinga (Source: barres fotonatura).

The caatinga conservation status is also critical. About 80% of the caatinga is already anthropizated. The main motive for this degradation is the food industry and mining.

5. PAMPA

Pampa is a biome that occupies a single state in Brazil, Rio Grande do Sul covering only 2% of the country. Pampa biome is also very well represented in Uruguay and northern Argentina. It includes a large diversity of landscapes, ranging from plains, mountains and rocky outcrops, but the more typical are grass fields with hills and isolated trees nearby water courses.

About 1,900 species of flowering plants have been catalogated in the Pampa, of which 450 are from the grass family (Poaceae) and 141 from Cyperaceae. Also Compositae (Asteraceae) and legumes (Fabaceae) species are frequent. In the areas of rocky outcrops we can found a large number of Cactaceae and Bromeliaceae.

Typical landscape of Pampa biome (Source: Flickr).

Regarding the fauna, there are up to 300 species of birds and 100 of mammals, with the emblematic species rhea, vicuña (South American camelids) or Cavia (rodents near the capybaras).

The pampas region has a very typical cultural heritage, shared with the pampas inhabitants of Argentina and Uruguay and developed by gaucho people.

The most developed economic activities are agriculture and livestock, which came along with Iberian colonization, displacing much of the native vegetation. According to estimates of habitat loss, in 2008 only 36% of the native vegetation remained . Only 3% of the pampa is protected under some form of conservation unit.

6. PANTANAL

Pantanal biome is a flooded forest steppe occupying the alluvial plain of the Paraguay River and its tributaries. It is therefore a wet plain which floods during the rainy season, from November to April. These floods favor a high biodiversity. It occupies only 1.75% of Brazil and is therefore the less extensive biome in the country.

When floods occur, a lot of organic matter emerges, since water carries all traces of vegetation and decaying animals favoring soil fertilization.

Grasses fields (Poaceae) configure the typical landscape in Pantanal. Not flooded areas are occupied by shrubs and even trees. About 2,000 different species of plants have been cataloged in Pantanal. Some of the more representative are palms (Arecaceae) and aquatic macrophytes (Lentibularaceae, Nymphaeaceae, Pontederiaceae).

Victoria regia (Nymphaeaceae) in the pantanal from Mato Grosso state (Source: Flickr).

Pantanal contains a high diversity of fishes (263 species), amphibians (41 species), reptiles (113 species), birds (650 species) and mammals (132 species), being the hyacinth macaw, the alligator or the black jaguar its most emblematic species.

After the Amazon, it is the second most preserved biome in Brazil since 80% of its extension retains its native vegetation. However, human activity also has made a great impact, especially with farming activities. Fishing and cattle are the most developed economic activities in the Pantanal. Also the establishment of hydroelectric plants is threatening the ecological balance of the environment, because if the flooding regime is broken, wildlife will be affected.

REFERENCES

• Guraim Neto, G. 1991. Plantas do Brasil, angiospermas do estado de Mato Grosso, Pantanal. Acta Botánica Brasileira 5: 25-47.
• Hoorn, C. et al. 2010. Amazonia through time: andean uplift, climate change, landscape evolution, and biodiversity. Science 330: 927.
• Martius, C.P.F. von. 1824. Tabula geographica Brasilie et terrarum adjacentium. Tabula geographica quinque provicias florae Brasiliensis illustrans. In: Martius, C.P.F. von ed. Flora Brasiliensis, Vol. 1, Part 1, Fasc. 21. Monacchi et Lipsiae.
• The Brazil Flora Group. 2015. Growing knowledge: an overview of seed plant diversity in Brazil. Rodriguésia 66: 1085-113.
• http://www.cnpso.embrapa.br/producaosoja/SojanoBrasil.htm
• http://www.mma.gov.br
• http://revistapesquisa.fapesp.br/2016/03/21/a-maior-diversidade-de-plantas-do-mundo/

How do the plants survive to cold?

This week I’m going to talk about how plants can survive in cold environments. The two biomes where cold is the main restrictive factor of the plant growth are tundra and alpine. In these places, the temperature can be under 0⁰C. Therefore, how do plants do to survive there?

INTRODUCTION

The cold is a restrictive factor to plant growth. It can be caused for two main reasons: height and high latitudes. When the height raises, the cold also does it; for each 100 meters of height, temperature gets down 1ºC. And in high latitudes, cold is caused by low insolation (only a little amount of sun’s heat is received). Plants can live until certain limits in high mountains, originating the alpine biome, and even become an ecosystem above the polar circle in the northern hemisphere, forming the tundra biome. Therefore, plants can survive in these cold ecosystems somehow. But, what kind of plants are and how do they do it?

On the left, tundra zone; and on the right, alpine zone (Image by Terpsichores).

VEGETATION STRUCTURE

First of all, we need to know what kind of plants are living in these places.

The trees’ growth is very restricted in both biomes. Indeed, trees are missing in tundra and only can be found in subalpine zone in the high mountains, between 1.600m and 2.400m; even so, the biggest height where trees can occur depends of different climatic factors and of the topographic relief. Once there are no trees, so there is no forest, we talk about alpine zone in high mountains.

Trees on subalpine zone (Photo taken by Jo Simon on Flickr).

On the other hand, shrubs are uncommon in both biomes, being the most of them smaller and creeping. That way, they can protect themselves against heavy frosts and cold winds, because they get covered of snow during the unfavourable period. Cranberry bush (Vaccinium vitis-idaea) is a good example of this kind of shrubs.

Cranberry bush (Vaccinium vitis-idaea) (Photo taken by Arnstein Rønning).

The herbs, bryophytes (e.g. mosses) and lichen together, are the most dominant of these two biomes, because they are the most abundant.

On the left, tundra in Siberia (Photo taken by Dr. Andreas Hugentobler); on the right, alpine zone in Monte Blanco (Photo taken by Gnomefillier)

PLANT ADAPTATIONS

Due to cold weather and other restrictive factors of these biomes, plants have had to adapt in different ways. In these two biomes, the summer is the favourable season and is when plants can develop themselves. But in winter, unfavourable period, they can only remain dormant in the form of seeds or reducing their activity to a minimum, thus avoiding own energy consumption.

For all these, these plants produce storage organs below ground, where they are protected from cold temperatures. Examples are rhizomes (underground stems, usually elongated and with horizontal growth, root-like) and bulbs (short and thick stem, covered with more or less developed fleshy leaves). These bodies ensure sufficient energy reserves during the unfavourable period. Furthermore, their roots are thick and can also accumulate reserves.

On the left, iris  rhizome (Iris) (Photo taken by David Monniaux); On the right, lily bulb (Lilium) (Photo taken by Denis Barthel).

On the other hand, their capacity to reach new zones to live, new habitats, depends more of the vegetative reproduction or asexual reproduction, that is, the emission of buds, underground organs, etc. And, in particularly, it is favoured by a high number of buds (plant organ that, when is developed, forms a stem, branch or flower).

Bud (Photo taken by Sten Porse).

A very curious adaptation, that can also protects against the wind, is that some plants are cushion-shaped. This morphology allows moisture and temperature to increase within the plant, and therefore stimulates the development and facilitates photosynthesis.

Cushion-shaped plant (Minuartia arcica) (Photo taken by Σ64).

Knowing that the favourable season is brief, plants usually are evergreen, that is, they have leaves during all year; and, that way, they don’t use energy to regenerate new leaves. Also, plant cells don’t freeze because they produce high concentrations of monosaccharides (simple sugars). So, it makes very difficult to freeze the perennial parts (those living all year).

Lucile's Glory-of-the-snow (Chionodoxa luciliae) (Photo taken by Ruhrfisch).

Moreover, their life cycle is also affected. The favourable period is so brief that it is often impossible to grow, forming flowers and fruits in the same year. Therefore, the plants usually live longer than a year and tend to perform only one of these three functions during the favourable season. Then remain dormant during unfavourable weather. So, its cycle is affected and it’s very impossible to live there to annual plants

Thanks to all these adaptations, plants have managed to live in such extraordinary places like these biomes, as incredible survivors. Remember, if you liked this article, you should not forget to share it. Thank you very much for your interest.

REFERENCES

• Notes of Botany, Phanerogamae, Science of the biosphere and Analysis of vegetation, Degree of Environmental Biology, UAB.
• Enciclopedia Catalana 1993-98. Biosfera. Volums. 9 Tundra i insularitat V. Krvazhimskii; A. N. Danilov. 2000. Reindeer in tundra ecosystems: the challenges of understanding System complexity. Publicat a tundra ecosystems: the challenges of understanding system complexity, V. 19, 107-110 pp.
• Walter H. 1998 Vegetació i zones climàtiques del món. L’estructuració ecològica de la geobiosfera. 2ªed cat. Promocions i Publ Univ SA, Barcelona
• http://161.116.68.143/website/geoveg/docs/Carrillo_06.pdf
• http://www.apicat.com/web/apiflora_1b.htm

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