Richness of Marchantiophyta and Bryophyta in a protected area of the Brazilian Amazon 1

ABSTRA CT The bryophytes of Gurupi Biological Reserve represent an important component of the biodiversity of the Amazon in the Brazilian state of Maranhão. This study aimed to investigate the richness of bryophytes (Marchantiophyta and Bryophyta) from Gurupi Biological Reserve and compare it with that found in other surveys conducted in Maranhão and in the northeastern part of the state of Pará, because the latter shows similarities with the study area in terms of vegetation, geography, demography, and history of occupation. We recorded 983 occurrences of bryophytes (549 Marchantiophyta and 434 Bryophyta) corresponding to 62 species (43 liverworts and 19 mosses), 39 genera, and 12 families. Of those 62 species, 25 have previously been collected from all regions of Brazil, two are restricted to two regions, and four are restricted to the northern (Amazon) region. The bryophyte species identified within the reserve correspond to 28.9% of the known bryophytes in Maranhão and 31.3% of the known bryophytes in northeastern Pará, the reserve therefore more closely resembling the latter area. The exclusively Amazonian elements found in the reserve underscore their affinity for this biome and their presence in the state of Maranhão. The importance of this conservation area to Maranhão and to the Amazon region of the state is confirmed by the high number of new records for the state (41 species), five of which are also new records for northeastern Brazil.


Introduction
The portion of the Amazon that lies within the Brazilian state of Maranhão, corresponding to the easternmost portion of the Amazon region, encompasses 81,208.40km 2 , including 62 cities, and represents 24.46% of the total area of the state (IBGE 2007;Martins & Oliveira 2011).Until the 1950s, this part of the Amazon was one of the least known, explored and inhabited in Brazil.It currently has the greatest population density in the Brazilian Amazon (IBGE 2007), and its vegetation cover has been reduced to less than 25% of its original size but remains little studied from a scientific standpoint (Moura et al. 2011).
According to Martins (2011), the large tracts of savanna and transitional vegetation located in Maranhão have diverted attention from research on the Amazon Biome in the state, and part of this inattention has also had the effect of intensifying changes in the local Amazonian landscape, as well as in land use and agricultural expansion, for more than 50 years.The term pré-Amazônia ("pre-Amazon"), coined by Brazilian politicians in the 1980s and adopted by the population, reflects the denial of recognition of elements in the Amazonian landscape and explains the failure of laws for the conservation of the Amazon rain forest, more rigid in terms of size of the legal reserve on rural properties compared with those applied in the savanna (Rocco 2005;Martins 2011).The remaining vegetation of the Amazon in Maranhão is basically composed of rain forest with lianas, alternating between dense and open vegetation, showing a gradual transition from the wetter forest type to semideciduous forest, along a north-south gradient (Muniz 2011).In addition, the region includes a mosaic of disturbed landscapes mainly represented by secondary forests, managed plantations and pastures (Araújo et al. 2011).
Among the few federal units of permanent preservation located in Maranhão, only the Gurupi Biological Reserve is located in the Amazon region (Martins 2011;MMA 2011;SEMA 2011).This reserve and the adjacent indigenous lands, such as Alto Turiaçu (530,525 ha), Awá (118,000 ha) and Caru (172,667 ha), form a biological unit of 11,628.42km 2 that harbors the best and the most homogeneous portion of the Brazilian Amazon in Maranhão (Araújo et al. 2011;Oliveira 2011).Therefore, the Gurupi Biological Reserve is the last protected area of Amazonian landscape in the state (Martins & Oliveira 2011).
The biggest threats to the Gurupi Biological Reserve arise from the same processes (sprawl and predatory exploitation) that plagued other areas of the Amazon in Maranhão.Among the key events of the territorial occupation of this region were the opening of major roads, such as the Belém-Brasília highway (BR-010) and BR-222, which gave rise to towns and districts where there were forests, and the opening of a new agricultural, forestry and pastoral frontier (Moura et al. 2011).Even being a strictly protected area, the reserve has been the target of illegal exploitation of timber resources and wildlife, which is only partially controlled through supervision (Moura et al. 2011).
The Amazon in Maranhão presents high species richness of different types of organisms, including environmental bioindicator, endemic and endangered species (Oren & Roma 2011;Oliveira et al. 2011;Rebêlo et al. 2011).The richness of the flora and floristic composition is partially known through phytosociological surveys of tree species, studies on flowering and fruiting patterns of trees and inventories of bee flora and Orchidaceae (Muniz 1998(Muniz , 2008(Muniz , 2011;;Silva et al. 1999;Marques et al. 2011).
The only records published to date on the bryoflora of the Amazon in Maranhão refer to a species of Ceratolejeunea that is new to science (Brito & Ilkiu-Borges 2012) and the study of bryophytes from the municipality of Mirinzal (Brito & Ilkiu-Borges in prep.)However, in a neighboring region that has a similar history of occupation, the northeastern portion of the state of Pará, much of the bryoflora has already been studied (Santos & Lisboa 2003, 2008;Lisboa & Tavares 2008;Ilkiu-Borges et al. 2009;Tavares et al. 2014), revealing high species richness, which represents about a third of the bryophytes in the state of Pará.
In this context, the bryoflora in the Gurupi Biological Reserve represents an important component to the knowledge of the biodiversity of the Amazon ecosystem in the state of Maranhão.This study aimed to investigate the richness of bryophytes (Marchantiophyta and Bryophyta) in the reserve and compare it with that found in other surveys conducted in Maranhão and northeastern Pará.

Material and methods
The Gurupi Biological Reserve (3°38'56"S; 46°41'42"W), created by federal decree (No. 95,614 of January 12, 1988), is located between the municipalities of Bom Jardim, Centro Novo do Maranhão and São João do Carú in the state of Maranhão.It is configured in a polygon slightly larger than 271,000 ha (Moura et al. 2011).According to the Köppen classification system (Köppen 1984), the climate of the region is type Am (humid equatorial).
The surveys were conducted from August 28 to September 5 of 2010 and from June 3 to 15 of 2011.The samples were collected on ten parcels of terra firme forest, five parcels each, respectively, in the northern and southern sectors of the Gurupi Biological Reserve, within the limits established by the "Loss of Biodiversity in the Centers of Endemism within the Scope of Deforestation" subproject of the Museu Paraense Emílio Goeldi National Institute of Science and Technology-sponsored project "Biodiversity and Land Use in the Amazon".Each parcel measured 10 × 10 m (100 m 2 ), totaling 1000 m 2 of study area.For the collection in the interior of a parcel, each was divided into five 2 × 10 m corridors, which traversed all types of substrates, and we avoided collecting samples from the overlapping areas of the parcel.The collection method was based on Yano (1984), and samples were deposited in the Herbarium of the Museu Paraense Emílio Goeldi, in the city of Belém, Brazil (code, MG).
The authors adopted the taxonomic classification systems devised by Crandall-Stotler et al. (2008) for Marchantiophyta and by Goffinet et al. (2008) for Bryophyta.Species were classified according to the substrates of occurrence, as described by Robbins (1952), and Gradstein et al. (2001) for classification of epiphylls.The termite mound substrate was treated separately because it does not fit into any of the above categories.
To assess abundance, the absolute frequency of the species was determined by adopting the classes defined by Silva & Pôrto (2007), which are based on the number of occurrences (number of times that the species occurs in a given parcel): rare = 1-5, infrequent = 6-10, constant = 11-20, frequent = 21-30, and very frequent = 31 or more.

Results and discussion
In Gurupi Biological Reserve, we recorded 983 occurrences of bryophytes (549 Marchantiophyta and 434 Bryophyta), corresponding to 62 species, 39 genera and 12 Acta bot.bras.28(4): 527-538.2014.families.Of that total, 43 species, 20 genera and five families belong to the liverwort group; and 19 species, 12 genera and seven families belong to the moss group (Tab.1).This study adds 41 new records to the bryoflora of Maranhão and five to that of northeastern Brazil.
The richness of liverworts was higher than was that of the mosses, which is in agreement with the literature on lowland rain forests (Gradstein et al. 2001).Lejeuneaceae (37 species), Calymperaceae (5 species), Fissidentaceae (5 species) and Sematophyllaceae (3 species) stood out, with greater specific richness, corroborating the assertions that are among the most representative families in the Neotropics (Gradstein & Pócs 1989;Gradstein 1994).
Regarding the distribution in Brazil, 25 species (40.3%) have already been collected in all regions of Brazil, two (3.2%) are restricted to two regions and four (6.4%) are restricted to the northern region (Amazonia).The remaining species occurred in three and four regions of the country (22.6% and 24.2%, respectively).It was expected that the bryoflora of the study area would harbor species of great ecological amplitude and therefore widely distributed but also common in the Amazon Biome, due to being in a region impacted by population growth and landscape changes.The presence of restricted species in the Amazon supports the argument of Martins (2011) for official recognition of the Amazonian landscape in the state of Maranhão.
Lejeunea obidensis was common in the Gurupi Biological Reserve.However, it is a little-known species, which has recently been rediscovered on an island in the opposite shore of Belém, in Pará (Moura et al. 2013), after more than a century of collecting the type (Spruce 1885).This indicates that the state of knowledge of some species is quite limited and can be amplified only through additional biological inventories .
Cheilolejeunea neblinensis was known only in Pico da Neblina, in the portion that belongs to Venezuela (Ilkiu-Borges & Gradstein 2008) and was recorded in an upland forest glade, in the oil province of Urucu, in the Brazilian state of Amazonas (Gradstein, unpublished data).It is cited for the state of Amazonas in the list of species of Brazilian flora (Costa 2013).
In addition to the type species, collected in secondary vegetation of upland in central Amazonia (Zartman & Ackerman 2002), Vitalianthus urubuensis was recorded in floodplain forest in the National Forest of Caxiuanã, in eastern Amazonia, by Lisboa & Osakada (2005).
As can be seen in Tab. 1, the most widely colonized substrate was tree trunk (living or decomposing), supporting data in the literature on tropical forests, in which these are reported to be the substrates most widely used by bryophytes, due to their abundance and ability to retain moisture (Pócs 1982;Richards 1984;Germano & Pôrto 1998).This result was expected, because this pattern was the same as that reported in other studies of bryophytes in the Amazon, including those in northeastern Pará (Santos & Lisboa 2003, 2008;Lisboa & Santos 2005;Lisboa & Tavares 2008;Ilkiu-Borges et al. 2009;Tavares et al. 2014).
The richness found in the Gurupi Biological Reserve was higher than that reported in most studies conducted in the Amazon in northeastern Pará, with the exception of Santos & Lisboa (2003) and Tavares et al. (2014).In most of the studies compared in Tab. 2, collection effort and study area were not measured, the exception being that conducted by Tavares et al. (2014).
Among the studies conducted in northeastern Pará, only those of Ilkiu-Borges et al. (2009) and Tavares et al. (2014) included liverworts in their analyses, which might explain the low liverwort richness attributed to that region (Tab.2).However, observing the richness of the divisions separately, the Gurupi Biological Reserve presents lower richness of mosses and liverworts than that recorded by Tavares et al. (2014) in Capitão-Poço, in Pará.It also presents lower richness of mosses in relation to the areas studied by Santos & Lisboa (2003;2008) and Lisboa & Tavares (2008).Santos & Lisboa (2003;2008) included several municipalities in their analysis and therefore evaluated an area much larger than that evaluated in the present study, which could explain why the richness of mosses was less pronounced in the Gurupi Biological Reserve.If the taxa are analyzed qualitatively, it appears that the species recorded in the reserve can be considered common, being distributed in several Brazilian states, as shown in Tab. 1.
In relation to other studies reporting on the bryoflora of Maranhão, the Gurupi Biological Reserve had richness that was lower than that recorded by Peralta et al. (2011)   and Costa (2013).However, those studies included species collected in different ecosystems and types of vegetation, whereas Maranhão presents not only Amazonian landscapes but also areas of savanna and shrublands (Yano et al. 2009;Oren & Roma 2011), which could explain the high number of species, especially mosses, recorded for the state.The richness found in the Gurupi Biological Reserve was higher than that recorded for the state of Maranhão by Yano et al. (2009).However, that study was based on samples collected in five states in northeastern Brazil and did not deal with the study of a locality or specific area in Maranhão.
Comparing the species collected in the Gurupi Biological Reserve with those recorded for the state of Maranhão in general and for northeastern Pará (Tab.1), the bryophytes from the reserve represent 28.9% of the bryophytes in the state as a whole and 31.3% of the those in northeastern Pará.Regarding the species collected in the reserve, 42 (28 liverworts and 14 mosses) have already been reported for northeastern Pará (Tab.2) and 17 (5 liverworts and 12 mosses) have already been reported for the state of Maranhão (Tab.1).
Our results lead us to assert that in terms of its bryoflora, the Gurupi Biological Reserve has more similarities with Acta bot.bras.28(4): 527-538.2014.
northeastern Pará than with the rest of the state of Maranhão.In addition, the reserve includes 15 species that have yet to be cited for northeastern Pará but have already been recorded for other localities in the Amazon, demonstrating the relevance of this area for the state of Maranhão and northeastern Pará (Tab.1).The presence of typical Amazon species such as Cheilolejeunea neblinensis, Fissidens prionodes Mont., Lejeunea obidensis and Vitalianthus urubuensis increase the importance of conserving the remaining areas of the Amazon Biome in Maranhão.
It was expected that the bryoflora of the study area would be similar to that of northeastern Pará (Santos & Lisboa 2003, 2008;Lisboa & Santos 2005;Lisboa & Tavares 2008;Ilkiu-Borges et al. 2009;Tavares et al. 2014), because both belong to the same biome and are areas impacted by occupancy and modification of the landscape, which explains the occurrence of species with wide ecological amplitude, which usually have a broad distribution.

Conclusion
Many of the species found in the Gurupi Biological Reserve were expected, given the degree of knowledge of the bryoflora of northeastern Pará, because the two areas belong to the same biome and have similar histories of occupation and modification of the landscape.The unique Amazon elements found in this reserve underscore their affinity for this biome.The importance of this conservation area to the state of Maranhão and to the portion of the Amazon within the state is confirmed by the high number of new records for the state, five of which are also new records for northeastern Brazil.

Table 1 .
Bryophyte species identified in the Amazon region of the state of Maranhão, Brazil, and its number of occurrences per substrate, occurrence classes, geographic distribution, records in the literature, voucher specimens, description and illustration citations.Co -Corticicolous; Ep -Epixylous; Ef -Epiphyllous; Te -Terrestrial; Cu -On termite mound; N. O. -Number of occurrences; NE.PA -northeastern Pará; MA -Maranhão.*New record for Maranhão; ** new record for northeastern Brazil.

Table 2 .
Richness of bryophytes recorded in the Gurupi Biological Reserve, at other localities within the state of Maranhão and in the northeastern part of the state of Pará.
*Group not included in the study cited.