Floristic checklist from an Atlantic Forest vegetation mosaic in Reserva Particular do Patrimônio Natural Fazenda Tabatinga , Pernambuco , Brazil

A floristic inventory was made in the Reserva Particular do Patrimônio Natural Fazenda Tabatinga to show the importance of small forest fragments for conservation of the biodiversity of the Atlantic Forest. The reserve protects a vegetation mosaic typical of coastal habitats in an area of ca. 20 ha, located in the northern part of the Brazilian Atlantic Forest. Samples of vascular plants were collected between January 2010 and November 2011, and altogether 329 species were recorded. These are classified in 230 genera and 79 families of angiosperms and two genera and two families of ferns. Among the species found, 28 are endemic to the Atlantic Forest, while others are rare and restricted to the Pernambuco Endemism Center. In addition, three threatened species were detected. The presence of endemic, rare, and threatened species, along with floristic patterns typical of coastal areas of Brazil, reinforce the importance of the area for the conservation.


INTRODUCTION
The Atlantic Forest holds up to about 8% of the world's biodiversity (Silva & Casteleti 2005).Within the Brazilian area of Atlantic Forest, 15,001 angiosperm species are recorded and almost 50% of them are considered endemic to this biome (Lista de Espécies da Flora do Brasil 2015).Extremely heterogeneous in composition (Tabarelli et al. 2005), the Atlantic Forest is considered a mosaic of vegetation types and includes forest formations and associated ecosystems, such as mangroves, and restingas (Stehmann et al. 2009).
The Atlantic Forest is recognized as a global hotspot of biodiversity because of the high levels of richness and endemism, associated with the deforestation suffered in the past (Mittermeier et al. 2004;Stehmann et al. 2009).The forest has been reduced to 11.4-16% of its original area (Ribeiro et al. 2009), and its remaining remnants are highly fragmented (Silva & Casteleti 2005).
The remnants of Atlantic Forest in Pernambuco state are mostly small and irregular in shape (Ranta et al. 1998;Trindade et al. 2007).Ranta et al. (1998) observed that most of the forest fragments in southern Pernambuco are smaller than 10 ha, while only about 10% are larger than 100 ha.These small fragments of Atlantic Forest are surrounded by agricultural areas with low chance of a long-term persistence (Silva & Casteleti 2005;Galindo-Leal 2005).
The current conservation paradigm views all fragments, regardless of size, as important for building a conservation mosaic and a regional landscape of connections among Atlantic Forest fragments (Silva & Tabarelli 2000).However, the biological relevance of small fragments has seldom been tested in terms of species richness and importance for preservation of endemic or endangered taxa.
The main goal of this study is to show how small forest fragments can be valuable for the conservation of angiosperms in northeastern Brazil.A survey of vascular plant species occurring in an Atlantic Forest remnant within the Reserva Particular do Patrimônio Natural (RPPN) Fazenda Tabatinga is presented.Included as well are occurrences of several endemic, rare, threatened, and exotic species.

Study site
The RPPN Fazenda Tabatinga (07°36′22″S, 034°49′14″ W) is located in the municipality of Goiana, Pernambuco state, Brazil, and has an area of ca.20 ha.According to MMA  (2000), the region where the area is located is of extreme biological importance and one of the priority areas for biodiversity conservation in the Atlantic Forest biome.The RPPN Fazenda Tabatinga was recognized by the Agência Estadual de Meio Ambiente (CPRH) of Pernambuco state by Decree 19,815 on 2 June 1997.The only information previously available about the plants of the area is an image guide by Cavalcanti et al. (2012).

Data collection
Botanical samples were collected monthly during both dry and rainy seasons from January 2010 to November 2011.There were 13 days of collection, which represent 72 hours of sampling effort (6 hours per day).The collections were made randomly along the entire area and the different vegetation types.Fertile plant material was dried using the usual methodology (Mori et al. 1985) and incorporated into the UFP herbarium collection with duplicates at JPB, NY, HRCB, UFRN, MAC, and MOBOT herbaria.
The plants were identified using literature and expertise of several taxonomists, as well as collections at UFP, JPB, and IPA herbaria.Families are organized based on Smith et al. (2006Smith et al. ( , 2008) ) for ferns and APG IV (2016) for angiosperms.The species names, abbreviations of authors, as well as information about geographical distribution, endemism, and new records for Pernambuco are based on the Brazilian Flora Group [BFG] (2015).
The RPPN Fazenda Tabatinga fragment is small, highly irregular in shape, and supports several species often found in secondary forests, such as Miconia albicans (Sw.)Triana and Sapium glandulosum (L.) Morong (Figure 2).Despite the size and shape, emergent trees are found, such as Lecythis pisonis Cambess., Eriotheca macrophylla (K.Schum.) A. Robyns, and Pterocarpus rohrii Vahl (Figure 2), as well as herbaceous plants in the understory, such as Cryptanthus alagoanus Leme & J.A.Siqueira, which is the only Bromeliaceae in the area.
These species have the following morphological characters: Miconia albicans is a shrub, easily distinguished from other species of Melastomataceae in the area by its leaves with lanulose trichomes abaxially (Figure 2); Sapium glan dulosum is a treelet with a pair of glands at the leaf base and as such it can be recognized among the other species of Euphorbiaceae in the area (Figure 2); Lecythis pisonis is a tree with circumsessile capsules which can be distinguished from other local species of Lecythidaceae by its larger and woody fruit (Figure 2); Eriotheca macrophylla (Malvaceae) is a tree with fissured bark, alternate leaves, white flowers with a short staminal tube and schizocarpic fruits with hairy endocarp; Pterocarpus rohrii can be differentiated from other species of Fabaceae by its tree habit, red exudate and the orange flowers with a vinaceous standard (Figure 2); and finally, Cryptanthus alagoanus, is a terrestrial herb in the Bromeliaceae which has leaves in rosettes and white flowers.
Among these species, Montrichardia linifera is distinguished from other species of Araceae by its arborescent habit and sagittate leaves.Blechnum serrulatum is a terrestrial herbaceous fern with pinnate leaf blades and sessile or shortly petiolate pinnae which are oblong, linear, lanceolate, and with serrate margins.Among the mangrove species, Avicennia schaueriana is recognized by its opposite leaves and tetramerous, zygomorphic flowers; Conocarpus erectus is recognizable by its alternate leaves and two glands at the leaf base; Laguncularia racemosa by its glands on the petiole apex, opposite leaves, and pentamerous, actinomorphic flowers; and Rhizophora mangle by its tetramerous, actinomorphic flowers, rhizophores and black dots on the leaves (Figure 3).
Among the semideciduous seasonal forest species, Esch weilera ovata is distinguishable from other species of Lecythidaceae by its smaller fruits (Figure 4).Tapirira guianensis can be recognized by its imparipinnate leaves, pentamerous flowers with 10 stamens and ovary with four styles (Figure 4).Hirtella racemosa can be distinguished from other species of Chrysobalanaceae by its shrubby habit and pink flowers, while Vismia guianensis is a shrub with yellow flowers and ferruginous trichomes on the stems and branches and orange exudate (Figure 4).Among the species most common in the restinga, Sesuvium portula castrum is recognizable due to its succulent leaves and pink flowers, and Dalbergia ecastaphyllum by its unifoliolate leaves, white flowers and samaroid fruits (Figure 4).Bambusa vulgaris Schrad.ex J.C.Wendl., Catharanthus roseus (L.) Don, Elaeis guineensis Jacq., Mangifera indica L., Terminalia catappa L., and Thespesia populnea (L.) Sol.ex Corrêa are invasive species generally found along the edges of the forest fragment (Figure 5).However, Elaeis guineensis is growing in the interior and forms dense agglomerations that aggressively replaces native species (Figure 5).
Invasive species found in the reserve have the following morphological characters: Bambusa vulgaris is arborescent with agglomerated culms; Catharanthus roseus is distinguished locally by its sub shrubby habit and pink flowers; and Elaeis guineensis is an arborescent palm with pinnate leaf blade, and orange to reddish, fleshy fruits (Figure 5).Terminalia catappa is a tree with obovate leaves, pentamerous and white flowers, and fleshy fruits (Figure 5), while Thespesia populnea is a shrub with alternate leaves, yellow flowers with a long staminal tube and schizocarpic fruits.
Species endemic to the Northeast Region and found in the reserve have the following morphological characters: Alseis pickelii is a tree with obovate leaves, glabrous adaxially and pilose abaxially at the axils of the secondary venation and capsular fruit (Figure 6); Annona pickelii is a treelet with simple and ferruginous trichomes on the branches and elliptical to ovate leaves (Figure 7); Aphelandra nuda is differentiated by its climbing, woody habit and pink corolla (Figure 7); Calyptranthes dardanoi is a shrub to treelet and can be recognized by its opposite leaves, paniculate inflorescence, flowers with calyx fused in bud which opens or falls as a calyptra and drupaceous fruits; and Dalechampia coriacea is a woody climber with cordate leaves and flowers involved by two bracts (Figure 6).Duguetia gardneriana is a treelet easily distinguished from other species of Annonaceae by its branches with scaly trichomes (Figure 6).Licania tomentosa is a tree differentiated from other species of Chrysobalanaceae by its floccose trichomes (Figure 6).Mimosa pseudosepiaria is a shrub with aculeate branches, simple, glandular trichomes and white flowers (Figure 6).Salzmannia nitida is a treelet with opposite leaves, inflorescences axillary glomerules, flowers tetramerous and yellow, with a bifid style (Figure 6).Swartzia pickelii is a tree with alternate, pinnate leaves, flowers with only one petal, dimorphic anthers, rachis and floral bud with ferruginous trichomes (Figure 7).

DISCUSSION
Although the small size when compared to most of forest fragments in the region, the RPPN Fazenda Tabatinga keeps the general floristic pattern found on lowland forests and restingas in northeastern Brazil (Freire 1990;Almeida-Jr. et al. 2007, 2009;Sacramento et al. 2007;Barbosa et al. 2011;Cantarelli et al. 2012;Alves et al. 2013).This evidence suggests the great conservation value of the area in the region, despite the intense anthropic pressure that typically affects small fragments with similar dimensions (Girão et al. 2007;Ribeiro et al. 2009;Lôbo et al. 2011).A comparative analysis with other floristic studies in the Atlantic Forest of Pernambuco state shows that even with its small area, the species richness of the RPPN Fazenda Tabatinga is considerable and exceeds the number of species found in other areas (Rodal et al. 2005;Almeida Jr. et al. 2007, 2009;Sacramento et al. 2007;Silva et al. 2008).The high richness may be due, among other factors, to the diversity of vegetation types found and the greater collection effort of the herbaceous component; some previous studies prioritized sampling of the tree layer (Almeida-Jr. & Zickel 2012;Santos-Filho et al. 2013;Medeiros et al. 2014).
The similar scope and collection effort applied to the various habits and vegetation formations confirm that herbs and shrubs play a greater role than is commonly indicated in the general model of floristic composition of the Atlantic Forest (Rodal et al. 2005;Almeida Jr. et al. 2007, 2009;Sacramento et al. 2007;Silva et al. 2008;Alves et al. 2013).
The heterogeneity of vegetation formations has a direct bearing on high species richness (Smith et al. 1997;Walker et al. 2003;Durigan et al. 2008) as evidenced in areas of Atlantic Forest (Dufour 2006;Pereira et al. 2007;Carvalho et al. 2008;Durigan et al. 2008;Santos-Filho et al. 2013).In addition, areas of ecotones tend to have higher species richness because of the coexistence of floristic elements from various biomes or ecosystems and the intense process of speciation (Smith et al. 1997;Walker et al. 2003).
Fabaceae was the most species-rich family, as found in other inventories in areas of Atlantic Forest (Rodal et al. 2005;Barbosa et al. 2011;Melo et al. 2011;Valadares et al. 2011).Poaceae and Cyperaceae also showed high species richness in the reserve and are commonly found in restingas and lowland Atlantic Forest of the region (Almeida Jr. et al. 2007, 2009;Sacramento et al. 2007;Barbosa et al. 2011;Melo et al. 2011;Cantarelli et al. 2012).Combined, these two families account for ca.56% of the herbaceous species of the reserve.
In addition to the high species richness, another factor that denotes the importance of the area is the presence of endemic, rare and threatened species.Among the species found, 66 are considered endemic to Brazil and 28 to the Atlantic Forest (Lista de Espécies da Flora do Brasil 2015).6).Some endemic species totally or partially follow the patterns of the Pernambuco Endemism Center (sensu Prance 1982), such as Aphelandra nuda Nees (BFG 2015) and Swartzia pickelii Killip ex Ducke (Cowan 1967;BFG 2015).
Aphelandra nuda Nees is rare, according to Kameyama et al. (2009).This species was known only from the type material and a collection of mid-19 th century but recently  northeastern Brazil, and the flora is as expected for restingas and associated ecosystems of the east coast of Brazil.In addition, the reserve supports threatened and endemic species, reinforcing its importance for the conservation of the flora of Pernambuco, despite being a small fragment.Thus, there is a need for a management plan that includes, among other aspects, the eradication of exotic species to ensure the protection and maintenance of the biodiversity of the site.

Figure 1 .
Figure 1.Map of study area with your vegetation types.A. Alluvial communities.B. Mangrove.C. Semideciduous seasonal forest.D. Restinga.Photos by D. Ferreira and B. Amorim.