Oldfield, Sara (comp.)(1997). Cactus and Succulent Plants - Status Survey and Conservation Action Plan. IUCN/SSC Cactus and Succulent Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. 10 + 212 pp.


Chapter 2. Regional Accounts

pag. 118-125:

The Brazilian Region

This vast region is further divisible on a country/vegetational basis as follows:

Extra-Amazonian Brazil and Easternmost Bolivia. Four major vegetational areas are recognised here, in order of their importance for succulent plants. The largest succulent genera, each with 15 or more endemic species, are Dyckia, Encholirium, Pilosocereus, Rhipsalis, and Melocactus (Smith and Downs 1974; Zappi 1994; Barthlott and Taylor 1995; Taylor 1991b). Only recently has the importance and plight of Brazilian succulents been specifically addressed by that country's authorities with the proposal to place various endangered cacti on Appendix I of CITES. However, the most serious problem at present is the almost complete lack of reserves to protect the many rare and endemic terrestrial (rather than epiphytic) succulents from the dry parts of north-east and south-east Brazil, and from the rocky East Brazilian Highlands, which rise out of the dry zone.

Eastern Brazil. This area includes the seasonally dry, deciduous thorn forests ("caatinga" and "agreste") and associated highlands ("campos rupestres") of northeastern Brazil, plus rock outcrops in the savannas ("cerrados") of the central/eastern parts of the adjoining states of Tocantins and Goiás, and, going south into south-eastern Brazil, dry areas and campos rupestres in the states of Minas Gerais (excluding the extreme west and south-west) and Espírito Santo (inland valleys and inselbergs only). This area is home to about 100 broadly defined Cactaceae species (90 per cent endemic, including 10 endemic genera, Taylor and Zappi, ined.), c. 80 more narrowly defined, succulent species of Bromeliaceae, represented by Encholirium (endemic, c. 20 spp.) and numerous species of Dyckia (c. 90 per cent endemic), and many, mostly weedy and inadequately understood Portulaca and Talinum taxa, besides a few succulents from other families.

Of special conservation concern are endemic species of the cactus genera Discocactus (6 spp., 5 endemic), Uebelmannia (endemic, 3 spp.), and Melocactus (M. conoideus, M. deinacanthus, M. glaucescens, M. paucispinus), which are Critically Endangered, Endangered, or Vulnerable and have been placed on Appendix I of CITES to afford them protection from the export trade. Most of these endemics are known from only one or very few localities, where the populations number between less than ten to at most 500 individuals. Discocactus horstii, D. placentiformis, D. pseudoinsignis, D. zehntneri ssp. boomianus, Melocactus glaucescens, M. paucispinus (both known from only two or three small sites each), and all Uebelmannia spp. (U. buiningii Critically Endangered, cf. Braun and Esteves Pereira 1988) are threatened primarily by trade, including regular collection of plants for seed production, or of seeds in habitat for wholesale export in large quantities. Discocactus bahiensis and Melocactus deinacanthus (the latter with only two populations known) are more seriously threatened by agricultural development, and both the former and D. zehntneri ssp. zehntneri had their ranges and numbers significantly reduced by inundation from the Represa de Sobradinho, a huge dam lake created in the 1970s on the São Francisco River (Bahia/Pernambuco). Repeated commercial collecting was only partly responsible for the decline of Melocactus conoideus, a species Critically Endangered due to the extraction of the quartz gravel in which it grows, and threatened with extinction at its type and only known locality above the expanding city of Vitória da Conquista, southern Bahia (Taylor 1992). Some documented plants still exist in cultivation and could be used to effect its reintroduction to the wild, should attempts to find new populations near its original habitat fail. The tall columnar species, Micranthocereus dolichospermaticus (from karstic Bambuí limestone outcrops of difficult access in south-west Bahia), has attractive young seedlings appreciated by the horticultural trade and may be in danger from the practice of felling mature individuals to facilitate the collection of seed for wholesale export. Export of seed is not controlled for CITES Appendix II species such as this, which deserves further investigation in habitat to determine if it should be proposed for Appendix I listing.

Threats

The driest zone of eastern Brazil, namely the "caatinga" and its ecotones with Atlantic Forest to the east (known as "agreste"), dry forests to the south (in Minas Gerais and Espírito Santo) and savannas ("cerrados") to its west (Maranhão to Goiás), represents a severely disturbed ecosystem (Andrade-Lima 1981), which has been subject to forest clearance for agriculture over more than two centuries. However, in general many succulents have probably suffered less than most other plants as a consequence of their frequent occurrence on rock outcrops unsuitable for cultivation or livestock grazing. Thus, many species of succulent Bromeliaceae (Dyckia, Encholirium), Coleocephalocereus, various Pilosocereus, and some Melocactus (e.g. M. ernestii, M. oreas) have significant populations in places dominated by gneiss/granite inselbergs, which are probably at less risk from habitat modification unless situated near expanding towns. Of those cacti that are not mainly restricted to rock outcrops, the least threatened are those which seem able to regenerate when their forest habitat is cut over. These include Cereus jamacaru, Pereskia grandifolia, P. bahiensis, and P. stenantha, and all are also conserved by their use in the form of impenetrable livestock fences or as hedges surrounding homesteads, both within and sometimes outside their natural ranges. A few very widely distributed endemic cacti which inhabit little-utilised or sufficiently diverse habitats are probably not at risk, even though their numbers may have dropped significantly, e.g. Facheiroa squamosa, Harrisia adscendens, Opuntia inamoena, Pilosocereus gounellei ssp. gounellei and P. pachycladus s.l. However, other, mostly wide-ranging succulents that are mainly found growing in the soil of the caatinga-agreste, or on exposed rocks more or less level with the floor of the surrounding thorn forest, have suffered considerable reductions in their distributions and abundance through forest clearance. Endemic cactus species affected in this way, whose ranges now appear to be strongly fragmented, include Arrojadoa penicillata, A. rhodantha, Brasilicereus phaeacanthus, Cereus albicaulis, Coleocephalocereus goebelianus, Melocactus salvadorensis, M. zehntneri, Opuntia palmadora, Pereskia aureiflora, Pseudoacanthocereus brasiliensis, Pilosocereus catingicola s.l., P. floccosus ssp. quadricostatus, P. flavipulvinatus, P. glaucochrous, P. pentaedrophorus s.l., Stephanocereus leucostele, Tacinga braunii, and T. funalis. Although most of these are unlikely to become seriously threatened in the immediate future, regular monitoring is essential if some are not to become endangered in the longer term. The same applies to some locally abundant and spectacular caatinga bottle-trees or "barrigudas" from the Bombacaceae (Cavanillesia arborea, Ceiba insignis s.l., C. jasminodora and Ceiba sp. indet. (SW Bahia)), whose habitats have decreased sharply, especially in southern Bahia, adjacent Minas Gerais and drier parts of western Espírito Santo.

Of more urgent concern are Melocactus azureus ssp. azureus and M. pachyacanthus, which have smaller ranges and are restricted to local low-lying outcrops of limestone, whose vegetation gets destroyed when the surrounding caatinga forest is cleared for cultivation. These taxa should be classified as Endangered on the basis of their known populations (see Taylor 1991b: 40-41), but further field studies are needed in the remoter parts of northern Bahia state, where additional and less disturbed habitats could exist.

Other succulents from the caatinga, whose native populations may be threatened, include the complex of species allied with Euphorbia phosphorea, certain members of the Cucurbitaceous genus Apodanthera (e.g. A. succulenta, A. congestiflora), Dioscorea basiclavicaulis, and Marsdenia sessilifolia, but, unfortunately, little is known about their conservation status, although some appear to be Rare or of restricted distribution (Rizzini 1989, Jeffrey 1992, Rizzini and Mattos-Filho 1992). Even if succulents found on raised rock outcrops within the caatinga are generally at less risk from agricultural development etc., some, and particularly those close to roads or human settlements, are at risk from the quarrying of stone for building materials. Those found only on limestone outcrops are probably most at risk (viz. Encholirium (3 spp. indet. cited by Andrade-Lima 1977:191), Facheiroa cephaliomelana s.l., Melocactus azureus ssp. ferreophilus, M. levitestatus, Micranthocereus dolichospermaticus, M. estevesii, Pilosocereus albisummus, P. densiareolatus, P. diersianus, P. flexibilispinus, P. floccosus, P. gounellei ssp. zehntneri, Opuntia saxatilis, O. estevesii), but gneiss, granite, and other crystalline rocks are also quarried and, if this should take place at the site(s) of one of the very local taxa, extinction could be sudden (e.g. Marsdenia megalantha (Mun. Iramaia, BA), Encholirium sp. nov. (Mun. Tanhaçú, BA), Coleocephalocereus purpureus, Espostoopsis dybowskii, Melocactus deinacanthus, Opuntia werneri). O. werneri is already threatened at one of its localities through granite quarrying (Rui Barbosa, BA) and the other species are each known from only one or two localities.

The few and mostly relatively small protected areas within the vast caatinga zone are as follows:

These can offer protection to only few and mostly the widespread species noted above, since, unfortunately, there are currently no significant protected areas in the southern part of the caatingas zone (central-S Bahia to N Minas Gerais), where higher species diversity and endemism is matched by a most disturbing level of habitat destruction (mainly for agriculture and charcoal production). One of the most important areas needing protection amongst the southern caatinga-agrestes is the middle section of the Rio Jequitinhonha valley (i.e. Araçuaí to Jacinto) in north-eastern Minas Gerais, where a remarkably rich assortment of succulent plants exists (Rizzini and Mattos-Filho 1992), including many endemic and potentially threatened cactus species (Taylor and Zappi 1992). Another promising site for protection, with a comprehensive range of southern caatinga cacti, including the rare Espostoopsis dybowskii, is situated to the east of the village of Porto Alegre, on the north bank of the Rio de Contas, Mun. Maracás, Bahia. Other sites need to be identified for the conservation of succulent taxa characteristic of the deep soils and Bambuí limestone outcrops in the valley of the São Francisco River (especially for Bombacaceae and columnar Cactaceae). One such would be the massive raised outcrop south of the town of Iuiá on the east bank of the river (Bahia) which, besides some spectacular bottle-trees of Cavanillesia and Ceiba growing around its base, has two very local endemics (Facheiroa estevesii, Opuntia estevesii) restricted to the rock itself. Other sites should be found on the west side of the river, where further endemics, such as the aforementioned Micranthocereus dolichospermaticus and Facheiroa cephaliomelana, are located.

The East Brazilian Highlands, with their mosaic of "campo rupestre" and "cerrado" vegetation (Giulietti and Pirani 1988; Zappi and Taylor 1994:77), represent the least modified of the environments considered under the present heading of eastern Brazil. However, they have as many if not more endemic succulent species than the caatingas-agrestes just discussed, and many are of extremely local occurrence and therefore potentially at risk. Widespread and mostly common, non-threatened exceptions include Cottendorfia florida, Cipocereus minensis ssp. minensis, Leocereus bahiensis, Melocactus bahiensis, M. concinnus, Pilosocereus aurisetus ssp. aurisetus, Micranthocereus purpureus, and Stephanocereus luetzelburgii, the latter two endemic to the extensive uplands of the Chapada Diamantina, Bahia, and also found within its national park (Mucugê-Lencóis).

Utilisation of the campos rupestres is limited to cattle grazing, with associated burning to induce regrowth, and local extraction of some plants, e.g. Eriocaulaceae (dried flower export trade - a serious conservation issue), orchids, and Vellozia spp., and there is also limited disturbance caused by small scale mining for gold and precious stones. Some parts where cerrado vegetation is more abundant are being cut over for the production of charcoal and later converted into Eucalyptus plantations, especially in Minas Gerais state, where this activity is one of the factors threatening Uebelmannia spp. and Cipocereus crassisepalus. The burning for cattle grazing does affect some native populations of succulents, but the regular collection of plants, and nowadays more especially of seed, of certain rare cacti may be cause for greater concern.

In addition to some of the CITES Appendix I taxa noted above, the following campo rupestre / cerrado cacti are known from only one or two small populations, or at best have a very localised range which does not include any kind of designated protected area (cf. Taylor and Zappi, ined.): Arrojadoa dinae (especially the rare variant known as A. eriocaulis), Arthrocereus rondonianus, Brasilicereus markgrafii, Cipocereus bradei, C. crassisepalus, C. laniflorus (sp. nov. ined.), C. pusilliflorus, Melocactus violaceus ssp. ritteri, Micranthocereus albicephalus, M. auriazureus, M. polyanthus, M. streckeri, M. violaciflorus, Pilosocereus vilaboensis, P. aurisetus ssp. aurilanatus, and P. fulvilanatus ssp. fulvilanatus and rosae.

Similarly restricted taxa located within protected areas are rather few: Arrojadoa bahiensis (Parque Nacional Chapada Diamantina, Bahia), Cipocereus minensis ssp. pleurocarpus (Parque Nacional da Serra do Cipó, Minas Gerais), Arthrocereus melanurus ssp. nov. (Parque Estadual de Ibitipoca, MG) and Pilosocereus rupicola (Estação Ecológica da Serra de Itabaiana, Sergipe). If extended slightly to its west, the first-listed would include a second population of the remarkable A. bahiensis. The last-named Pilosocereus is possibly endangered or even extinct, but has not been investigated in habitat in recent times. The Serra da Piedade (Mun. Caeté, MG) is not a designated protected area, but a site of religious significance, which has a population of Arthrocereus glaziovii, a specialised species restricted to rocks very rich in iron ("canga"), many of its former habitats having disappeared through ore extraction. It is also the type and only known locality for Dyckia simulans. Numerous, other, little-known species of Dyckia and some Encholirium are recorded from various serras in central and eastern Goiás and especially from the regions of Diamantina, the Serra do Cipó and serras further south in Minas Gerais state. These deserve further study in the field to determine their taxonomic and conservation status. A peculiar and specialised cactus, found in the sandy cerrados bordering on the caatinga and campo rupestre zones, from western Bahia to central-eastern Minas Gerais, is Cereus mirabella. It is widespread but of erratic occurrence and much of its habitat is being destroyed by charcoal producers, so its status needs to be monitored carefully.

Locations where new protected areas are needed to assist the conservation of the above listed rarities, including the earlier discussed CITES Appendix I cactus taxa, are as follows and are listed in the Action Proposals.

Atlantic Forest. This comprises the coastal rain forest ("Mata Atlântica" in its strictest sense) and sandy littoral dunes ("restingas") of north-eastern Brazil and their extensions southwards, where the former broadens and merges with the planalto forests of south-eastern and southern Brazil, reaching the northern part of Rio Grande do Sul state. The area, which is very humid, has a high diversity of epiphytic cacti from the tribe Rhipsalideae, but, as is now well known, only a small fraction of the original forest remains. Endemic Rhipsalideae include the horticulturally and economically important genera Schlumbergera (6 spp.) and Hatiora (5 spp.). A few very widespread or regionally common taxa, such as the epiphytic Hatiora salicornioides f. salicornioides, Lepismium cruciforme, L. houlletianum, L. warmingianum, Rhipsalis floccosa, R. lindbergiana, R. teres, R. elliptica, and R. cereuscula, and the non-epiphytes Brasiliopuntia brasiliensis, Opuntia monacantha, Cereus fernambucensis, Pilosocereus arrabidae, and P. brasiliensis are probably to be regarded as at low risk, but the remaining Brazilian endemic species are of conservation concern to varying degrees. For example, the wide-ranging but erratically occurring restinga taxa, Melocactus violaceus ssp. violaceus and ssp. margaritaceus, are threatened at various points in their ranges by touristic developments and other forms of urban expansion. Particular species diversity "hot spots" are found in southern Espírito Santo state (between Domingos Martins and the Serra do Caparaó) and around and between the great cities of Rio de Janeiro and São Paulo, various taxa being endemic to very small areas. The flora of southern Espírito Santo is poorly understood, but includes a recently described species of Christmas Cactus, Schlumbergera kautskyi (known from only two or three small sites), and the remarkable, red flowered Rhipsalis hoelleri. Other species are represented by disjunct populations, often at their northern limits, such as Hatiora salicornioides f. cylindrica, Rhipsalis cereoides, R. pilocarpa, R. campos-portoana, and Schlumbergera microsphaerica (the latter two within the boundaries of the Parque Nacional do Caparaó).

Further south the diversity of epiphytic and epilithic Rhipsalideae increases markedly along the coast and in the Serra do Mar westwards from Cabo Frio (RJ), where also an isolated member of tribe Cereeae, Pilosocereus ulei, is narrowly endemic on coastal rocks. Rhipsalis pentaptera, a species relatively common in cultivation, is presumed to be extinct in the wild, since its only recorded native site is within what is now the city of Rio de Janeiro (at Praia da Gávea). Other rare and probably vulnerable (but inadequately studied) species of Rhipsalideae from the region of Rio de Janeiro include Rhipsalis pacheco-leonis, R. cereoides, R. mesembryanthemoides, and Schlumbergera orssichiana. Rhipsalis burchellii is known for certain only from the metropolitan region of São Paulo, and a substantial part of its presumed former habitat appears to have been either destroyed completely or severely affected by industrial pollution. Hatiora herminiae and H. epiphylloides are each known from only two relatively small areas of montane cloud forest between Rio and São Paulo and should be classified as endangered due to forest clearance, even though they are at least partly found within protected areas (the former in the Parque Estadual Campos do Jordão, SP, the latter in the Parques Nacionais do Itatiaia, RJ/MG, and Serra da Bocaina, RJ/SP). Other species of Rhipsalideae from this part of the Atlantic Forest and montane forest zones appear to have greater ranges, but are infrequent, disjunct or seldom observed. These include Hatiora salicornioides f. cylindrica, Rhipsalis neves-armondii, R. grandiflora, R. pilocarpa, R. clavata, R. pulchra, Schlumbergera truncata, S. russelliana, and S. opuntioides. Protected areas that include or probably include one or other of these species are the Parques Nacionais da Floresta da Tijuca and da Serra dos Orgãos (RJ), the Parques Estaduais de Ilha Grande (RJ), de Ibitipoca (MG), de Campos do Jordão and de Picinguaba (SP), and the Reservas Biológicas de Poço das Antas, de Paranapiacaba, da Juréia, Ilhabela and that proposed for the Serra do Japi (SP). Destruction of the Atlantic Forest has been greatest in north-eastern Brazil, where only 5-10 per cent remains and, therefore, our knowledge of the flora is correspondingly fragmentary. It is quite possible that epiphytic Cactaceae from here have become extinct before discovery and description. In Paraíba and Pernambuco remnants of this forest include the "brejos" on higher land away from the coast, where the watersheds are important for the human populations living below them. Such forests are currently being studied and catalogued as part of an Anglo-Brazilian initiative (Plantas do Nordeste), with great emphasis being placed on the need to preserve these floristic refuges which, inter alia, include disjunct populations of cactus epiphytes, such as Lepismium cruciforme and Rhipsalis crispata. Further south, in coastal Bahia (up to 100 km inland), between the capital Salvador and Belmonte to the south, where annual rainfall is generally in excess of 1750 mm, there are occasional records of various species of Rhipsalideae, indicating a once rich centre of diversity including Hatiora salicornioides f. cylindrica, Rhipsalis paradoxa ssp. septentrionalis, R. baccifera ssp. hileiabaiana., R. russellii, and R. oblonga. With so little forest remaining it seems reasonable to assume that here all of these are threatened to a greater or lesser extent, even if some may benefit from protection in local reserves, such as the Reserva Biológica Federal de Una (south of Ilhéus). Also part of the Brazilian north-east, is the Archipelago of Fernando de Noronha, a Federal Environment Protection area. These Atlantic islands are home to at least one endemic cactus, Cereus insularis (a relative of the Brazilian coastal C. fernambucensis), which seems adequately protected at present. A second species, or perhaps a form of the first, is C. ridleii, which has not been seen since its original collection in the 1950s and may now be extinct. It is no longer in cultivation, so far as is known.

Some of the best-preserved Atlantic Forest and coastal habitats are those found in southern Brazil, in the states of Paraná, Santa Catarina, and northern Rio Grande do Sul, between sea level and almost 2000 m. Here a wide variety of Rhipsalideae could be protected if deforestation can be controlled. These include the horticulturally important Easter Cacti, Hatiora gaertneri and H. rosea (its range includes Parque Nacional de São Joaquim, SC), which are characteristic of Araucaria forest, the peculiar Rhipsalis dissimilis (a widespread but infrequent SE Brazilian lithophyte protected in the Parque Estadual Vila Velha, Paraná), and the forest epiphytes Rhipsalis trigona, R. paradoxa, R. pulvinigera, R. puniceodiscus, R. pachyptera, and R. campos-portoana. There are also at least 11 endemic and 5 non-endemic Dyckia spp., all of unknown conservation status. In the western part of southern Brazil, in the drainage of the Rio Paraná, the situation is rather different, much of the humid and savanna forest having been cleared for agriculture. Fortunately, there are no endemic succulents known from this vegetation, which extends westwards into eastern Paraguay, where it is better preserved.

Besides those mentioned already, protected areas in the species-rich Atlantic slopes of southern Brazil include the Parque Nacional de Superagui and the Federal Environmental Protection Area and Ecological Station of Guaraqueçaba (Paraná), which probably include at least some epiphytic taxa. Non-endemic succulents found in the forested and coastal parts of southern Brazil that are probably out of danger include Cereus hildmannianus and Lepismium lumbricoides.

The third and fourth areas of extra-amazonian Brazil comprise the plant communities mainly composed of grasses etc. ("campos") of southernmost Brazil (Rio Grande do Sul state) and the savannas or "cerrados" of Central-western Brazil. The relatively smaller succulent floras of these two areas and the perceived threats have much in common with those of eastern Paraguay, eastern Bolivia, and Uruguay, as discussed below.

Campos. The "campos" of Rio Grande do Sul are important for the high number of endemic and non-endemic but probably threatened taxa belonging to the Cactaceae-Notocacteae, i.e. the genera Parodia (Notocactus) and Frailea, and tribe Trichocereeae (Gymnocalycium). There are also two endemic species of Dyckia (Bromeliaceae), their conservation status Unknown. Other succulents are representatives of widespread elements characteristic of the floras of Argentina and Paraguay and probably not at serious risk as species, e.g. Cereus aethiops, Echinopsis spp., Pereskia nemorosa, and Lepismium lumbricoides (an epiphyte). As explained below, under Uruguay, the habitats of many of the endemic and threatened Notocacteae are rocky outcrops amongst agricultural land, much of the terrain being cultivated for arable crops or grazing pasture. Exceptions include the Parque Nacional Aparados da Serra, situated at the northern border of the state with part inside adjacent Santa Catarina, and including the habitats of the endemic Parodia haselbergii and P. graessneri, which are presumed to be adequately protected. The conservation status of most of the remaining 40 or so Parodia (Notocactus) taxa (many of doubtful taxonomic standing), c. 15 Frailea and 4 Gymnocalycium spp. (2 endemic), which are concentrated in the southern part of Rio Grande do Sul, needs to be determined. However, some populations are known to be very small and illegal collection to satisfy the demand for novelties by hobbyists in Europe and elsewhere is certainly taking place. There appear to be no other officially designated, protected areas including Notocacteae/Trichocereeae in Rio Grande do Sul.

Western cerrados. The "cerrado" in the states of Mato Grosso, Mato Grosso do Sul, Goiás, the western parts of south-eastern Brazil and easternmost Bolivia (Santa Cruz) comprise open savanna woodlands on oligotrophic (strongly weathered and leached) soils and included rocky outcrops, inselbergs and uplands, such as the Chapada dos Guimarães (Mato Grosso). The altitude varies between 300-1500 m and rainfall is in excess of 1000 mm per annum with high average temperatures for most of the year. This area has very few endemic succulents, including 8 poorly known species of Dyckia and only 5 botanically distinct species of cacti: Arthrocereus spinosissimus, Cereus adelmarii, C. saddianus, Echinopsis hammerschmidii, and Frailea chiquituna (the latter two are Bolivian endemics found on inselbergs in the ecotonal region between the "cerrado" and Amazonian forests), all of whose conservation status is inadequately known (the Arthrocereus may benefit from any protection afforded by its location inside the Parque Nacional da Chapada dos Guimarães). Widespread cactus taxa include the highly variable Discocactus heptacanthus s.l. and Pilosocereus machrisii s.l. (both fragmented into numerous ill-defined microspecies by some authors), besides a treelike species of Cereus found on calcareous outcrops, whose identity is uncertain at present (C. calcirupicola?), C. bicolor (botanical affinity uncertain) and the shrubby C. euchlorus (= Praecereus sp.). One or more Opuntia spp., Cleistocactus horstii (? - C. baumannii), Frailea cataphracta s.l. (including F. matoana, EW according to Hunt 1992), Cereus (Monvillea) kroenleinii, Gymnocalycium anisitsii, G. marsoneri (G. matoense), Harrisia guelichii (Cereus balansae), Pereskia sacharosa, Jacaratia corumbensis, Dyckia ferox, D. microcalyx, and Deutercohnia meziana also occur, but have the major parts of their ranges in adjacent Paraguay. Although the fireswept "cerrados" are not noted for succulent plants, there may be reason for concern about the status of even the widespread taxa in this large geographical area, and especially taxa restricted to calcareous soils and rocks, which are at greater risk from habitat conversion. Large scale farming operations, for both arable (especially soybean) and livestock, are modifying the environment and local assessments of the likely effects on succulent plant populations are needed. In easternmost Bolivia this environment has been used for cattle grazing for more than 200 years and is now being cultivated in some areas. The seasonally inundated region of the Pantanal (Brazil), which includes raised rocky areas where succulents are found, is currently benefitting from ecotourism and may thus be less at risk from agricultural development.

 

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Melocactus margaritaceus