RENATO MELLO SILVA / USPVellozia luteola, endemicRENATO MELLO SILVA / USP
23 years ago, at the beginning of December, four botanists and one zoologist from São Paulo squeezed themselves into a brown old Chevrolet and covered roads full of potholes, under a heat of almost 40 degrees, en route to the northeast of Minas Gerais. That was the first exploratory expedition of the Flora of the Rupestral Fields project over the mountain ranges of the Cadeia do Espinhaço, a 1,100 long strip that occupies a major part of central Brazil, in particular Minas Gerais and Bahia. One of the regions chosen for the detailed flower survey was the Grão-Mogol Ridge, then as yet little studied, but with a rich and varied vegetation that was already threatened by deforestation and by prospecting for diamonds.
Located 500 kilometers to the north of Belo Horizonte, where the cerrado (savanna) gives way to the caatinga (scrubland), the Grão-Mogol Ridge is one of the areas with the highest endemism, that is, it is a depositary of unique plant species. The so-called rupestral field predominate there – vegetation made up of bushes and trailing plants that grow between the rocks or in the shallow, sandy, acid soil that is poor in nutrients and organic matter.
The results of this and of the other 20 trips that followed – the most recent of them in March 2000, in a Chevrolet D-20 truck with four-wheel drive – is now taking the form of a special edition of the Boletim de Botânica (Botany Bulletin) of the University of São Paulo (USP), to be published next month, in a partnership with Editora Hucitec. It is the first of the four volumes to be launched by the end of next year, and in its 250 pages, it brings an identification guide, illustrations and the descriptions of 50 families of plants. Of the most abundant group alone, plants with flowers, or angiosperms, the first 34 of the 117 families appear.
Coordinated by botanist José Rubens Pirani, from USP’s Biosciences Institute, the complete collection will have about 1,000 pages and will be an illustrated inventory of the flora peculiar to the rupestral fields, savannas and forests of the region, with their own morphological and physiological adaptations – the plants form islands of vegetation in the midst of rocky and rugged terrain, at altitudes varying between 650 and 1,100 meters, in a region of transition between two distinct ecosystems, the savanna and the scrub. When it is complete, the work will show the structures, the geographical distribution and the times of flowering and fructifying of the 472 genera and the 1.067 species of plants from the Grão-Mogol. Of this total, 60 are endemic – they live only on this mountain range where it rains heavily from November to March, and serves as a watershed between the rivers that form the São Francisco, which run to the west, and those that make their way to the Atlantic, to the east.
Collective portrait
With this survey, the Serra de Grão-Mogol finds itself on a level footing, in terms of scientific knowledge, with broader stretches of the Cadeia do Espinhaço, which have been studied for longer. In 1987, a list came out of the 1,590 plant species that live on the Cipó Ridge, with an area four times larger, a one-hour journey from Belo Horizonte – and on an paved highway. In 1995, it was the turn of the Pico das Almas, a neighboring mountain range, with all its flora of 1,044 species described in a book published in England, with the participation of researchers from USP.
Small and distant, away from the routes of economic interest and no infrastructure for tourism, the Grão-Mogol Ridge was scientifically explored – and the samples of the plants analyzed – by about 100 researchers from Brazilian and international institutions. Those taking part included teams from the Botany Institute of the São Paulo State Secretariat for the Environment, the State University of Campinas (Unicamp), the State University of Feira de Santana (UEFS), the Federal University of Juiz de Fora (UFJF), the Federal University of Minas Gerais and from the Royal Botanic Gardens, of Kew, Britain.
Pirani believes that this work will not only make comparative studies possible but will also facilitate the recognition and preservation of the plants by those who live in the region. It may also stimulate other researchers and even teachers and students from schools in the region to carry out studies in the anatomy, germination, development or local uses of the plants of the mountain range, whose name is a reference to the Great Mogul diamond, with its 700 carats (one carat equals 0.2 grams), found in India in the 16th century – in those same times, when mining in Brazil was at its peak, a similar stone was said to have been discovered in the region. Another purpose of the project is to help to establish or to reinforce public policies that reconcile the conservation of the environment with sustainable agricultural practices.
At the moment, the forests are cut down to make charcoal, or they are cleared by fire to make way for small plantations of cassava, pineapple, sugarcane, beans or corn. Nor has a way yet been found to detain the advance of pastures and the action of prospectors who, mainly in search of diamonds, leave the soil and the gravel overturned – and it will be difficult for the natural vegetation to grow there again where they have passed. Classified in 1998 as an area of very high biological interest, and hence a priority for conservation, Grão-Mogol is part of the Serra da Bocaina State Park, created in that same year. However, the researchers recall, the measures for the effective setting up are still under way.
“Besides being diversified and characteristic, the flora of the Grão-Mogol Ridge is extremely beautiful”, Pirani sums up. Hatpin flowers grow there, chiefly species from the Syngonanthus genus. They are trailing plants with white, straw-colored or golden flowers, which look like little daisies. They are picked in the ancient way, the greater part of the crop being exported. “The exploitation of these flowers is worrying, because removing the flowers prevents the formation of the seeds that guarantee the continuity of the species”, says the researcher. Another plant typical of there are three species of friar’s heads, from the Discocactus and Melocactus genera. They are cacti with flowers and full of spines that won this name in a lighthearted allusion to the sometimes entirely bald head of a friar.
Unique species
Then the canelas de emas (rhea’s shanks) (Vellozia spp.) stand out for their large lilac flowers that look like lilies, and for their slender stalks covered with scales, much exploited for use as fuel – they help the fire to catch, because they burn even when wet, due to the resins they contain. Looking upwards, we can see one of the tall and leafy trees typical of the region, called monjoleiros in Portuguese, which belong to the Pterodon genus, with pink bark and a height that varies from 7 to 20 meters, found in the lowlands and rocky slopes. It is only in Grão-Mogol that the Trembleya hatschbachii still lives, a bush found close to streams, from the glorybush family, “with explosions of pretty yellow blossoms”, in the description of the botanist from USP. Besides the endemic species, there are also those that easily rouse one’s curiosity, like Drosera graomogolensis, a plant that is all red, distinct, with a 7 centimeter stalk and carnivorous: attracted by its bright color, ants and other insects end up stuck to the gooey surface of its leaves.
The rarities of the region began to become better known in 1818, when the German explorers Carl von Martius (1794-1868) and Johann Baptist von Spix (1781-1826) covered the Serra da Canastra, to the south of Grão-Mogol, in one of the first known expeditions to the area. Almost 300 years afterwards, one can quantify with precision how rare are some of the species that live in the mountains there. It is only there that characteristic plants grow, like the three species found between rocks or stuck to cliffs, forming great clumps or extensive gardens –Vellozia prolifera, Barbacenia riparia andVellozia luteola, known only by their scientific names.
Along with the other representatives of the Velloziceae family, made up of some 250 species (the majority of them in the Cadeia do Espinhaço), the three species were intensely studied at the end of the 80’s by Renato Mello-Silva, also from USP. To start with, he tried to understand how some peculiarities of the leaves of these plants, like the variations in the fibers or the occurrence of cracks, could help to elucidate the evolution of the group. Mello-Silva found new species of this family in Grão-Mogol, confirmed the endemism of others, and found that some of them show variability in the distribution of the fibers in the insides of the leaves and in the kinds of hairs at the base of the flowers – an indication that mechanisms of speciation are under way, as the differentiation and formation of new species is called.
Comparisons
Having totted up these two decades of surveying, which was supported by FAPESP, the National Council for Scientific and Technological Development (CNPq) and the World WildlifeFund (WWF), Pirani estimates that the scientists from the group in which he took part first of all studying for his master’s degree – he was 23 years old on the first expedition – thoroughly searched an area with some 400 square kilometers, with visits in all the seasons of the year, trying to collect plants with flowers or with fruits of the largest number possible of species.
It was a sample regarded as excellent, not least because “it is virtually impossible to cover entirely an surface of the dimensions of a mountain range, above all with so many areas of very difficult access”, notes the researcher from USP. As each trip lasted from one week to one month, they spent 315 days on the mountains – almost one year, therefore, of field work. Today, the venture that started to be idealized before the end of the 70’s by botanist Nanuza Luiza de Menezes – the owner of the Chevrolet used in the first expeditions to the mountains and still today one of the hallmarks of Brazilian botany – was also reflected in the form of 3,700 samples, the greater part of which kept in the herbarium of USP’s Biosciences Institute.
“This survey was indispensable for us to start studying the biogeographical history of the flora of the region and to establish the relationship with other mountainous areas of South America, such as the mountains and plateaus of Goiás, the Tepuis of Venezuela, the mountains of the Guyanas, and even the Andes”, comments Ana Maria Giulietti, from the UEFS and the project’s first coordinator. The Tepuis to which she refers are the steep mountains, at an altitude of some 1,000 meters and a flat top, which occupy the northern portion of the Amazonian region.
“The flora of the rupestral fields and the cerrados that of the Tepuis are nowadays isolated and far away, but they still share some elements, providing evidence that they had been closer thousands or perhaps a few million years ago.” Comparing two kinds of vegetation that are over 6,000 kilometers apart is just one of the research projects that are now becoming feasible. Straight away, the botanists intend to define with greater precision the similarities and the differences with the other ranges of the Cadeia do Espinhaço that have now been pored over: Cipó Ridge, the Pico das Almas ( The Soul’s Peak) and the Serra de Catolés, also with a high degree of endemism. “The comparisons will give rise to patterns, models or questions that will help to give direction to the continuity of the studies”, says Pirani.
“We will probably be able to detect groups of plants common to all the areas, those that have a greater concentration in one or another, and yet again those that may be indicative of the evolution of the Espinhaço.” But nobody intends to stop there. “Around Grão-Mogol, there are also the Serra de Botumirim, the Serra de Itacambira and the Serra Deus-me-Livre, still little explored”, explains Pirani. Unveiling the secrets that they are keeping may perhaps be a task for another 20 years’ work.
The Project
Herbarium of the Botany Department of USP’s Biosciences Institute (nº 98/08489-7); Modality Infrastructure Program 4; Coordinator
José Rubens Pirani – from USP’s Biosciences Institute; Investment
R$ 610,989.71
