Floristic survey of the Mata do Junco Wildlife Refuge , Capela , Sergipe State , Brazil

(Floristic survey of the Mata do Junco Wildlife Refuge, Capela, Sergipe State, Brazil). Seeking to expand the floristic studies for the Atlantic rainforest, we herein present, based on field trips (January 2011 to April 2013) and herbarium records, a list of vascular plants found in the Mata do Junco Wildlife Refuge, State of Sergipe, Northeastern Brazil. We registered a total of 380 species, 244 genera and 80 families, with 45 new occurrences for the Atlantic rainforest of the State of Sergipe. The most representative families were Fabaceae (36 species), Cyperaceae (29) and Poaceae (28). Herbs were the most representative regarding habit (167 species or 44%). We found two threatened species: Caesalpinia echinata Lam. and Campylocentrum pernambucense Hoehne, both in the “endangered” category. Overall, the results indicate that the Mata do Junco Wildlife Refuge is floristically similar to other areas of Atlantic rainforest in the State of Sergipe. Moreover, the existence of new records and of a threatened native species reinforces its importance for conservation.


Introduction
The Atlantic rainforest encompasses a set of ecologically important ecosystems (Turner & Corlett 1996, Moore 1998, Moura 2006, Stehmann 2009, Forzza et al. 2012) with a high degree of endemism (Moura 2006, Forzza et al. 2012).These factors, associated to the risk of disappearance, were responsible for the inclusion of the Atlantic rainforest as one of the 25 biodiversity hotspots in the world (Myers et al. 2000).
According to IBGE (1993), the Atlantic rainforest occurs on an almost continuous coastline, between the States of Rio Grande do Sul and Rio Grande do Norte, and includes the inner regions of the continent, in the States of Goiás, Mato Grosso do Sul, Minas Gerais, Ceará and Piauí.This biome is very heterogeneous and consists of a series of phytophysiognomies (Capobianco 2001), from stricto sensu (dense, mixed and open) to seasonal forests (deciduous and semi-deciduous), mangroves, Restingas, montane forest and Brejos Interioranos (IBGE 1993, Tabarelli et al. 2005).
Regarding the richness of plants, it is estimated to house about 15,782 species, distributed in 2,257 genera and 348 families and, of this total, 7,155 species (45%) are endemic to the Atlantic rainforest.The angiosperms are represented by 13,708 species, followed by 1,230 species of bryophytes, 840 species of ferns and licophytes and four species of gymnosperms (Stehmann et al. 2009).
In the State of Sergipe, only 9.3% of the original Atlantic rainforest cover remains (Fundação SOS Mata Atlântica/INPE 2013).In this State, the Atlantic rainforest is distributed in 403 fragments (Santos 2009), small and isolated (Jerusalinsky et al. 2006), having become vulnerable enough to degradation (Landim et al. 2015).Currently, there are 19 conservation units, with only three of them in the "fully protected" category (Brasil 2000) and covering areas of Atlantic rainforest: the Biological Reserve of Santa Isabel (covered by Restingas and mangroves, both phytophysiognomies of the Atlantic rainforest), the Serra de Itabaiana National Park (transition ecotone of the Atlantic rainforest with the Caatinga) and the Mata do Junco Wildlife Refuge, a semideciduous Atlantic rainforest (Brasil 2010, 2011a, 2011b, Farias 2013, Souza-Alves et al. 2014).
Currently, there are few studies of the Atlantic rainforest in the State of Sergipe (Landim & Siqueira 2001, Vicente et al. 2005, Mendes et al. 2010, Dantas et al. 2010, Lucena et al. 2010, Souza-Alves et al. 2014, Landim et al. 2015).Nevertheless, recent studies have shown the importance of Atlantic rainforest fragments in Sergipe, such as its high richness of plants (Mendes et al. 2010, Landim et al. 2015) and the conservation of endemic species of fauna (Souza-Alves et al. 2014).
Considering the small number of floristic studies for the Atlantic rainforest of Sergipe and the urgent need for conservation action in this biome, we present and analyze a list of vascular plants collected in the Mata do Junco Wildlife Refuge (also indicating threatened species) in order to fill the scientific research lacunas for this biome in the State of Sergipe.

Materials and methods
Study site -the Mata do Junco Wildlife Refuge is located in the county of Capela (10°30'35"S and 37°03'17"W), in the State of Sergipe, Northeastern Brazil (figure 1).This protected area covers an area of 894.76 ha (Sergipe 2007), representing the second largest Atlantic rainforest reserve in Sergipe (Santos et al. 2007, Sergipe 2007).It was created in order to protect the Atlantic rainforest, its natural resources, and especially the Guigó monkey (Callicebus coimbrai Kobayashi & Langguth -1999), endemic to the Atlantic rainforest of the States of Bahia and Sergipe (Jerusalinsky et al. 2006, Sergipe 2007).
In the Mata Junco Wildlife Refuge, altitude varies from 113 to 172 m (Souza-Alves 2013) and the soils are of type Argissolo Vermelho-Amarelo (EMBRAPA/SUDENE 1975).The vegetation is distributed in two isolated fragments (with 522 and 372.76 ha each), covered by secondary forest remnants, where individuals can reach an average height of over 15 m in advanced stages of regeneration, with the highest reaching up to 20 m (Santos et al. 2007, Santos 2009, Morato et al. 2011, Souza-Alves et al. 2014).In general, the forest canopy ranges from closed -with many epiphytes, lianas, climbers, and abundant litter -to open (Santos et al. 2007).In the latter, the understory is composed of a thin litter layer, broadleaf shrubs and small trees.When the opening of the canopy is increased, gaps are formed with higher density of herbs, as well as the edges of the fragments.
The climate is characterized as Type As -tropical rainy with dry summer according to the climatic classification of Köppen (Alvarez et al. 2014).The rainy season runs from March to August, while the dry season runs from September to February.The total precipitation ranges from 1500-1800 mm per year and the annual average temperature is around 26 °C (Sergipe 2011).
Data collection and analysis -The species listed in this study were compiled through field trips from January 2011 to April 2013, being four times a year in 2011 (intervals of three months), six times a year in 2012 (intervals of two months, however twice a month) and twice a year in 2013 (intervals of two months), totaling eighteen fields trips and including sampling in the dry and rainy season every year.Walks were carried out along trails and edges throughout the study area, seeking out fertile specimens (with flower and/or fruit).Then these specimens were herborized according to the usual standards (Mori et al. 1989) and placed in the Herbarium of the Federal University of Sergipe (ASE).The specimens were identified by experts and by comparison with herbarium vouchers from the Federal University of Sergipe -ASE (acronyms following Thiers 2016).
To complement the field trips, we searched information from plants collected in Mata do Junco Wildlife Refuge in the database of the Herbarium of the Federal University of Sergipe (ASE) and of the Herbarium of the Federal University of Pernambuco (UFP) using the speciesLink (CRIA 2016).Subsequently, the vouchers present at these herbaria were checked and, when possible, updated to the lowest taxonomic level.The vouchers with doubtful identification were excluded.The adopted classification system was APG III (2009).To define the habit of the individuals (defining all their respective species), field observations were used as well as descriptions on the voucher labels (for the herbarium survey), following the literature settings (Gonçalves & Lorenzi 2007) and checked in the Flora do Brasil (2020) em construção.The spelling of names was checked in the Flora do Brasil (2020) em construção and the distribution of species in Brazil also in this database and recent papers for the Atlantic rainforest of the State of Sergipe (Prata et al. 2013, Oliveira & Landim 2014, Oliveira et al. 2014, Souza-Alves et al. 2014, Landim et al. 2015, Oliveira et al. 2015, Prata et al. 2015).
Based on the compiled floristic list, we searched for endemic species of the Atlantic rainforest (Stehmann et al. 2009) as well as threatened species (IUCN 2015, Martinelli & Moraes 2013).
In order to verify the floristic similarity between the study site and other areas of Atlantic rainforest (Alves-Araújo et al. 2008, Mendes et al. 2010, Amazonas & Barbosa 2011, Alves et al. 2015, Landim et al. 2015) and with areas of Caatinga (Ferreira et al. 2013, Silva et al. 2013), we generated a dendrogram obtained from a binary matrix (presence/absence) with the distribution of the species recorded in the papers analyzed using the unweighted pair group method with arithmetic mean (UPGMA) based on the Sørensen coefficient in the Past 2.17 software (Hammer et al. 2013).

Results
Altogether 380 species were found (24 or 6% endemic species for the Atlantic rainforest), with five fern species and 375 species of angiosperms (some examples, figures 5 and 6), distributed in 244 genera and 80 families, with 45 new occurrences for the Atlantic rainforest of the State of Sergipe (table 1).Considering angiosperms and ferns and lycophytes (table 2), the number of species found in the Mata do Junco Wildlife Refuge represent about 82% of the number of species and families recorded for the county of Capela and about 27% of the number of species and 53% of the families recorded for the Atlantic rainforest of the State of Sergipe (CRIA 2016, Flora do Brasil 2020 em construção).
Regarding the Atlantic rainforest of the northeast region and of Brazil, the Mata do Junco Wildlife Refuge has, respectively, about 5% and 2% of the species and about 36% and 32% of the families (Flora do Brasil 2020 em construção).
About 11% of the species have a wide distribution in Brazil (considering those occurring in 26 States as well as the Federal District) and about 4% of the species have restricted distribution (considering those occurring in three or fewer States).
The families with the highest number of species (figure 2) were Fabaceae (36 species), Cyperaceae (29), Poaceae (28), Asteraceae (25), Rubiaceae (22).Malvaceae (15) and Orchidaceae (14), corresponding to 44% of the total species and 9% of the number of families.The families with only one species account for 9% of all species and 41% of all families.
The cluster analyses showed the formation of two distinct groups: a group formed by studies in areas of Atlantic rainforest and other in areas of the Caatinga.The Mata do Junco Wildlife Refuge showed greater floristic similarity with the areas of Atlantic rainforest of the State of Sergipe (figure 4).

Discussion
The number of species and families found for the Mata do Junco Wildlife Refuge was higher than three of four surveys analyzed in the Atlantic rainforest of the State of Sergipe (table 3) with similar sampling efforts (Vicente et al. 2005, Dantas et al. 2010, Mendes et al. 2010, Landim et al. 2015).
Ageratum conyzoides L., Casearia sylvestris Sw., Cyperus surinamensis Rottb., Coutarea hexandra (Jacq.)K. Schum.and Mandevilla scabra (Hoffmanns.ex Roem.& Schult.)K. Schum, present in the compiled floristic list (table 1), are examples of widely distributed species in Brazil (Flora do Brasil 2020 em construção).Some of these (A.conyzoides, C. sylvestris and C. surinamensis) occur in all biomes in Brazil (Flora do Brasil 2020 em construção), being than A. conyzoides is recognized as an invasive species of crops (Klein & Fellipe 1991).In the Atlantic rainforest, C. surinamensis and M. scabra are typical of edges and capoeiras (Nascimento et al. 2012, Ribeiro et al. 2015), while C. sylvestre and C. hexandra are tree species classified in early secondary about the ecological group and are common in both the Atlantic rainforest and the Cerrado (Silva et al. 2003, Paula et al. 2004).
Stachytarpheta   The number of endemic species found in the Mata do Junco Wildlife Refuge was lower, considering that about 48% (6,933) of all vascular species of the Atlantic rainforest are endemic (Stehmann et al. 2009).Among the endemic species, we found Caesalpinia echinata Lam.(Fabaceae), a species for which there are no accurate records of natural populations in the State of Sergipe (Ferreira & Barreto 2015).Even after consulting the forest managers of the Mata do Junco Wildlife Refuge, it was not possible to confi rm if the individual collected is native to the area.Considering the high probability that no native populations of Caesalpinia echinata Lam currently exist in Sergipe State (Rocha 2010), we believe that this collected individual was cultivated.The most representative families (Fabaceae, Cyperaceae and Poaceae) were also those with the greatest richness in the study by Mendes et al. (2010) in the Serra de Itabaiana National Park, Agreste region of the State of Sergipe (table 3).Moreover, they were also the most representative families in some fragments of Atlantic rainforest of the State of Pernambuco (Alves-Araújo et al. 2008).In the paper by Souza-Alves et al. (2015), also based in data gathered in the Mata do Junco Wildlife Refuge, specifically with trees and climbers, only the family Fabaceae was similar among the three most representative families of this present paper (table 3).
Furthermore, Fabaceae was the most representative in five of six papers analysed for the Atlantic rainforest of the State of Sergipe (table 3).In relation to the northeast of Brazil, it was the most representative family in a remnant of Atlantic rainforest on the northern coast of the State of Bahia (Alves et al. 2015), located near the border with Sergipe and in an area of Atlantic rainforest of Paraíba (Amazonas & Barbosa 2011), for example.The family is cited as the second most representative for the Atlantic rainforest, with a richness estimated at 945 species (Stehmann et al. 2009).Moreover, it is the largest family in number of species in Brazil and one of the largest in the world (Souza & Lorenzi 2012).Part of success of this family is mainly explained by its great morphological diversity and symbiotic relationships with nitrogen-fixing bacteria that live in nodules on the roots of the plants (Queiroz 2009).
Among the most representative families of this study, Poaceae, Asteraceae, Rubiaceae and Malvaceae are on the list of the ten most diverse families of the Atlantic rainforest, and only Cyperaceae, the second family with the most species in this study, is not mentioned in this list (Stehmann et al. 2009).The presence of water resources in the Mata do Junco Wildlife Refuge (Morato et al. 2011) can provide micro-habitats for the species of Cyperaceae which are abundant in flooded areas (Souza & Lorenzi 2012); this fact may have contributed to their richness in this area.
The presence of Cyperaceae and Poaceae among the most representative families in the Mata do Junco Wildlife Refuge, may be a consequence of the existence of some open and disturbed areas (Santos et al. 2007, Morato et al. 2011), where Cyperaceae and Poaceae are typical (Souza & Lorenzi 2012).Besides, we conducted an intense sampling effort in this paper for the herbaceous layer, mainly due to the presence of two experts of these families in the herbarium ASE.
The Orchidaceae family was only the seventh in richness for the Mata do Junco Wildlife Refuge (figure 2).Nevertheless, the family had the second highest number of species ( 14) among the areas analyzed in the Atlantic rainforest in the State of Sergipe (Mendes et al. 2010-30 species, Dantas et al. 2010-five species, Landim et al. 2015-three species, Vicente et al. 2005 -zero species).This family was not cited as being between the most representatives in none of the papers analysed for the Atlantic rainforest in the State of Sergipe (table 3).The family Orchidaceae is cited as the most diverse of the Atlantic rainforest (Stehmann et al. 2009) and presents some species listed as biological indicators for conservation (Hietz 1999, Pessoa & Alves 2012).We believe that the occurrence of degradation in the Mata do Junco Wildlife Refuge (Souza-Alves et al. 2014) may have contributed to the low observed richness of this family.
Myrtaceae is another family that did not show a high number of species in the study area (figure 2), but that is cited as the sixth most diverse family of the Atlantic rainforest (Stehmann et al. 2009).Among the papers analyzed with similar samplings, only in Landim et al. (2015), was the Myrtaceae family among the most representative families (table 3).Despite this family not being representative in the Mata do Junco Wildlife Refuge, its richness was similar to most areas of Atlantic rainforest in the State of Sergipe (except Landim et al. 2015) and various areas of Atlantic rainforest in the northeast of Brazil, for example in the State of Bahia (Alves et al. 2015), Pernambuco (Costa-Jr et al. 2007) and Paraíba (Pereira & Alves 2006, Amazonas & Barbosa 2011).
In some areas of Atlantic rainforest in Sergipe, as in this study, the herbaceous component had the highest number of species, as noted for vegetation of areias brancas of Serra de Itabaiana National Park (Dantas et al. 2010), however, it is an open shrubby vegetation type.In addition, the herbaceousshrub phytophysiognomy was the one with the greatest number of species in the Serra de Itabaiana National Park, considering a focus on all plant phytophysiognomies (Mendes et al. 2010).However, these areas actually represent an ecotone transition from the Atlantic rainforest to the Caatinga (Mendes et al. 2010).Moreover, the herbaceous habit was the most representative in fragments of Atlantic rainforest of the State of Pernambuco (Alves-Araújo et al. 2008).In an Ombrophilous Lowland Forest remnant located in the southern State of Sergipe (called Mata do Crasto), the habit of trees prevailed in vegetation in the number of species (Landim et al. 2015).We  believe that the intense sampling effort carried out for the herbaceous layer has contributed to this group being the most representative in the Mata do Junco Wildlife Refuge.
Among the threatened species, Caesalpinia echinata Lam.(Fabaceae) is a tree with a restricted distribution between the States of Rio Grande do Norte and Rio de Janeiro, with the exception of Sergipe (Flora do Brasil 2020 em construção).As previously discussed, we believe that this collected individual of C. echinata was cultivated.The other threatened species, Campylocentrum pernambucense Hoehne (Orchidaceae) is an epiphytic herb, restricted to the Atlantic rainforest of the States of Alagoas, Paraíba, Pernambuco and Sergipe (Flora do Brasil 2020 em construção).According to the criteria of IUCN (2015), species in the "endangered" category are facing a very high risk of extinction, mainly because of the reduction in their population size and their geographic distribution which is currently an area less than 5000 km² and limited to severely fragmented areas.The presence of a threatened native species in the Mata do Junco Wildlife Refuge -Campylocentrum pernambucense Hoehne -reinforces the need for conservation of this area.Besides, we suggest that this species become the focus of new population studies to investigate its vulnerability.
Despite the presence of common species of the Brazilian Caatinga in the compiled floristic list (Flora do Brazil 2020 em construção), the Mata do Junco Wildlife Refuge was very dissimilar -regarding floristic composition -to the Caatinga areas analyzed of the State of Sergipe.We believe that the greater floristic similarity observed between the areas of Atlantic rainforest of Sergipe was influenced by the geographical proximity of these areas, because the phytophysionomic differences between them contribute to their floristic heterogeneity.
The existence of some degraded areas or in regeneration (Santos et al. 2007, Morato et al. 2011, Souza-Alves et al. 2014) in the Mata do Junco Wildlife Refuge and intense sampling effort carried out for the herbaceous layer may has contributed to the richness of herbs and lower number of endemic species found.Moreover, it is possible that the isolation of the two fragments that make up the vegetation of the Mata do Junco Wildlife Refuge can act to diminish the richness of tree species (Souza-Alves et al. 2014).The most degraded portion of Atlantic rainforest of the State of Sergipe is located in the region of the Mata do Junco Wildlife Refuge, characterized by the smallest fragments with the greatest distances between them (Santos 2009).
In general, the vegetation of the Mata do Junco Wildlife Refuge was considered similar to the other areas of Atlantic rainforest already studied in the State of Sergipe, in relation to species number and composition of species and families.Most species have a wide distribution in the Atlantic rainforest of Brazil and even in other biomes such as the Caatinga.

Figure 1 .
Figure 1.Location of the Mata Junco Wildlife Refuge, Sergipe State, Northeastern Brazil.

Figure 2 .
Figure 2. Vascular plant families with the highest number of species in the Mata do Junco Wildlife Refuge, Sergipe State, Northeastern Brazil.

Figure 3 .
Figure 3. Species (%) for each habit in the Mata do Junco Wildlife Refuge, Sergipe State, Northeastern Brazil.

Table 1 .
List of the 380 vascular plants collected in the Mata Junco Wildlife Refuge, Sergipe State, Northeastern Brazil.*: endemic to the Atlantic rainforest.+: new occurrence for the Atlantic rainforest of Sergipe.Vouchers with (**) are deposited in the UFP herbarium, being the remainder deposited at the ASE herbarium.

Table 2 .
Richness of the species and families of the Atlantic rainforest.Source: CRIA (2016); Flora do Brasil (2020) em construção.

Table 3 .
Results from selected papers on the fl ora of the Atlantic rainforest in the state of Sergipe.*:considering only the method of sampling by plots.**:disregarding data of phytosociological studies.Nectandra grandifl ora Nees (Lauraceae), Odontocarya acuparata Miers (Menispermaceae), Psychotria brevifl ora (Schltdl.)Müll.Arg.(Rubiaceae), as well as being new records for the Atlantic rainforest of Sergipe, are new records for the Northeastern Brazil (Flora do Brasil 2020 em construção).The number of new records for the Atlantic rainforest of the State of Sergipe could have been higher if we considered only the database of Flora do Brasil (2020) em construção.However, due to the increase of papers in recent years for the Atlantic rainforest of Sergipe, the number of new occurrences decreased.Therefore, we suggest an update in the database of this platform, to refl ect the new species occurring in the Atlantic rainforest of the State of Sergipe.