# An Ecological Comparison of Floristic Composition in Seasonal Semideciduous Forest in Southeast Brazil: Implications for Conservation

Authors: Sérgio de Faria Lopes; Ivan Schiavini; Ana Paula Oliveira; Vagner Santiago Vale
Journal: International Journal of Forestry Research
 (2012)

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## Abstract

We examined floristic patterns of ten seasonal semideciduous forest sites in southeastern Brazil and conducted a central sampling of one hectare for each site, where we took samples and identified all individual living trees with DBH (diameter at breast height, 1.30 m) ≥4.8 cm. Arboreal flora totaled 242 species, 163 genera, and 58 families. Fabaceae (38 species) and Myrtaceae (20 species) were families with the largest number of species. OnlyCopaifera langsdorffii and Hymenaea courbaril occurred at all sites. Multivariate analysis (detrended correspondence analysis and cluster analysis) using two-way indicator species analysis (TWINSPAN) indicated the formation of a group containing seven fragments in which Siparuna guianensis was the indicator species. This analysis revealed that similarities between studied fragments were due mainly to the successional stage of the community.


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## Body

## 1. Introduction

The extent of seasonal semideciduous forests (SSFs) in Brazil is underestimated because of its naturally fragmented distribution [1, 2]. Semideciduous seasonal forests occur along the contact zone between Atlantic forest and the diagonal of opened formations [3–5], comprising three different scenarios:  (1) in northeastern Brazil, the SSFs form a marked belt (<50 km) in transition between the coastal rainforest and semiarid formations (Caatinga), but also occur in enclaves of montane forests, the altitude marsh [6, 7]; (2) the transition between the Cerrado and the coastal Atlantic forest in southeastern Brazil involves an extensive occurrence of SSFs to the south, up to the east of Paraguay and northeast of Argentina, forming a complex mosaic with the Cerrado vegetation in the west;  (3) in southeastern Brazil, a large Araucaria forest confronts subtropical coastal Atlantic forest, and the SSF appear to the west and south as a transition to the Chaco forests, and to the southeast with fields or the southern pampas [8, 9], and beyond disjunct areas located in Mato Grosso and Tocantins states [10].In southeast Brazil, SSFs are distributed widely in sites with a seasonal rainfall regime, characteristic of the Atlantic forest and Cerrado domains. In the Atlantic forest domain, SSF is the predominant typology, and in the Cerrado domain, SSF occurs in enclaves, associated with permanent or intermittent watercourses [12] and should be regarded as lato sensu Atlantic forest, since it presents a floristic-structural identity similar to forests of the Atlantic forest domain [12].Semideciduous seasonal forests suffered the same degradation process as other Brazilian ecosystems. Since the 1970s, there was an accelerated replacement of natural vegetal formations to pasture and use for agriculture, transforming extensive areas into an important agriculture area for grain and fruit production and livestock [13]. This rural reorganization was determined by the II National Development Plan (NDP), which collaborated for a modern agricultural deployment. With increasingly intense adoption of mechanization and land use, SSFs were drastically reduced, with only a few remaining in Southeast Brazil.Habitat fragmentation transforms the original landscape into different dynamic units that continually modify its structure [14]. Furthermore, the occurrence of disturbance histories on different scales and heterogeneity environmental landscapes can influence the species composition of forest fragments [15] and form species richness patterns according to the fragment successional stage [16, 17].Therefore, owing to the similar process of disturbance in southeastern Brazilian forest formations and being located in the same catchment area, it is expected that the remaining SSF will have the same floristic pattern.This work aims to analyze the floristic composition and regional richness in the arboreal species of ten fragments of SSF in southeastern Brazil, in order to answer the following questions: (1) what is the alpha diversity in sampled fragments? (2) is there a floristic pattern that represents the SSF in the studied region? (3) is the beta diversity in SSF similar to patterns found in other tropical forests?


## 2. Material and Methods

### 2.1. Floristic, Geographic, and Climate Data

We elaborate a floristic list from the tree species compilation in ten semideciduous seasonal forest fragments (according to Veloso classification [18]), distributed in five counties of southeastern Brazil (Table 1). Studied sites are located in the extreme west of Minas Gerais state, defined by geographic coordinates 18° 29′–19°40′ S and 47°30′– 49°53′ W (Figure 1).Table 1
Information of ten seasonal semideciduous forest fragments in southeastern Brazil analyzed regarding regional tree flora composition.
SiteCountiesArea (ha)Latitude (S)Longitude (W)Altitude (m.a.s.l.)1Araguari20018° 29′ 50″48° 23′ 03″6802Ipiaçu4018° 43′ 39″49° 56′ 22″5303Monte Carmelo11918° 44′ 59″47° 30′ 56″9104Uberaba7019° 40′ 35″48° 02′ 12″7905Uberlândia17,518° 40′ 26″48° 24′ 32″6006Uberlândia3018° 57′ 03″48° 12′ 22″8807Uberlândia22,319° 08′ 39″48° 08′ 46″9308Uberlândia1619° 10′ 04″48° 23′ 41″8009Uberlândia3518° 55′ 40″48° 03′ 51″89010Uberlândia2018° 51′ 35″48° 13′ 53″890Figure 1
Location of the ten sites of seasonal semideciduous forest studied in the region of Triângulo Mineiro, Minas Gerais state, southeastern Brazil.The studied region is part of a relief global set, named the “Domain of Central Brazil Tropical Plateaus” by Ab'Saber [19], and the “Plateaus and elevated plains of the Paraná sedimentary basin” by the RADAM project [20]. The soils in the studied areas are predominantly red nonferric latossols (LV) [21]. The predominant climate in the studied region is tropical savanna (Aw Megathermic), characterized, according to Köppen classification [22], by rainy summers and dry winters. The clearly seasonal climate has two well-defined seasons, where the winter season (April to September) has approximately six months of drought, and the summer season (October to March) is warm and rainy. The average annual temperature lies between 23°C and 25°C, with July the month with the lowest average temperature (16°C). The annual rainfall ranges from 1160 to 1460 mm [23].


### 2.2. Data Collection and Analysis

We conducted a central sampling of one hectare from each fragment of SSF, in an attempt to exclude edge effect and to obtain uniform samples, avoiding the ecotones of the adjacent formations. Central sampling gave priority to sites without the influence of watercourses (gallery forest), savanna formations (cerrado  sensu stricto), and others forestry formations (dry seasonal forest and cerradão), since these vegetation contact areas vary considerably between fragments and would lead to changes in the species listing of each area. In each central sampling, all individual living trees with a DBH (diameter at breast height, 1.30 m) of ≥ 4.8 cm were recorded and identified.We identified the species using literature, queries in herbarium, and specialists. For specific binomial formation, we employed the w3 Tropicos database [24]. We deposited fertile material to the Uberlandia Federal University herbaria (Herbarium Uberlandensis: HUFU). Vegetative samples of all species were deposited at the Laboratory of Plant Ecology at the same university. Species were classified into families, according to the Angiosperm Phylogeny Group III system [25].We compiled all species present in the inventories to undertake the floristic composition analysis. We carried out the analysis by preparing a binary database (presence/absence), containing the tree species listed in each fragment. We only considered individual trees identified at the species level in this database composition. For the Alpha diversity evaluation, we used the Shannon diversity index (H′) and the Pielou evenness index (J′).We used the binary database for the measurement of richness analysis, and also for the total number of species projection, we used first- and second-order, nonparametric jackknife estimators, in addition to Chao and Chao 2 estimators, which were capable of projecting total species richness from the samples of species richness [26], with 5,000 randomizations. We conducted the analysis using the EstimateS 8.0 program [27].


### 2.3. Multivariate Analyses

We did similarity and sorting analysis utilizing the FITOPAC SHELL 1.6.4 program [28], using an absolute density matrix for the species of ten sites, considering only those species with two or more occurrences, since species that had just one occurrence did not contribute to the floristic site ordering for floristic similarity. For categorical floristic data (presence and absence), we analyzed the similarity between sites, using the same absolute density matrix, transformed into presence/absence. We used the Sørensen similarity coefficient [29] and the unweighted pair group method with arithmetic mean (UPGMA) for a dendrogram graphical representation.We applied multivariate analysis to quantitative tree species floristic data (abundance) present in all the compared fragments. For this, we realized a data ordination by using the detrended correspondence analysis (DCA, [30]). In addition, to define predominantly the indicator and preferred species of the floristic groups, based on frequency and density (species with n≥5 individuals), we used dichotomous hierarchical division using TWINSPAN (two-way indicator species analysis, [31]), from an absolute data matrix and its frequency at the 10 sites, with a cut level of 0, 2, 5, and 10. These analyses were made by PC-ord for Windows program version 4.0 [32].


## 2.1. Floristic, Geographic, and Climate Data

We elaborate a floristic list from the tree species compilation in ten semideciduous seasonal forest fragments (according to Veloso classification [18]), distributed in five counties of southeastern Brazil (Table 1). Studied sites are located in the extreme west of Minas Gerais state, defined by geographic coordinates 18° 29′–19°40′ S and 47°30′– 49°53′ W (Figure 1).Table 1
Information of ten seasonal semideciduous forest fragments in southeastern Brazil analyzed regarding regional tree flora composition.
SiteCountiesArea (ha)Latitude (S)Longitude (W)Altitude (m.a.s.l.)1Araguari20018° 29′ 50″48° 23′ 03″6802Ipiaçu4018° 43′ 39″49° 56′ 22″5303Monte Carmelo11918° 44′ 59″47° 30′ 56″9104Uberaba7019° 40′ 35″48° 02′ 12″7905Uberlândia17,518° 40′ 26″48° 24′ 32″6006Uberlândia3018° 57′ 03″48° 12′ 22″8807Uberlândia22,319° 08′ 39″48° 08′ 46″9308Uberlândia1619° 10′ 04″48° 23′ 41″8009Uberlândia3518° 55′ 40″48° 03′ 51″89010Uberlândia2018° 51′ 35″48° 13′ 53″890Figure 1
Location of the ten sites of seasonal semideciduous forest studied in the region of Triângulo Mineiro, Minas Gerais state, southeastern Brazil.The studied region is part of a relief global set, named the “Domain of Central Brazil Tropical Plateaus” by Ab'Saber [19], and the “Plateaus and elevated plains of the Paraná sedimentary basin” by the RADAM project [20]. The soils in the studied areas are predominantly red nonferric latossols (LV) [21]. The predominant climate in the studied region is tropical savanna (Aw Megathermic), characterized, according to Köppen classification [22], by rainy summers and dry winters. The clearly seasonal climate has two well-defined seasons, where the winter season (April to September) has approximately six months of drought, and the summer season (October to March) is warm and rainy. The average annual temperature lies between 23°C and 25°C, with July the month with the lowest average temperature (16°C). The annual rainfall ranges from 1160 to 1460 mm [23].


## 2.2. Data Collection and Analysis

We conducted a central sampling of one hectare from each fragment of SSF, in an attempt to exclude edge effect and to obtain uniform samples, avoiding the ecotones of the adjacent formations. Central sampling gave priority to sites without the influence of watercourses (gallery forest), savanna formations (cerrado  sensu stricto), and others forestry formations (dry seasonal forest and cerradão), since these vegetation contact areas vary considerably between fragments and would lead to changes in the species listing of each area. In each central sampling, all individual living trees with a DBH (diameter at breast height, 1.30 m) of ≥ 4.8 cm were recorded and identified.We identified the species using literature, queries in herbarium, and specialists. For specific binomial formation, we employed the w3 Tropicos database [24]. We deposited fertile material to the Uberlandia Federal University herbaria (Herbarium Uberlandensis: HUFU). Vegetative samples of all species were deposited at the Laboratory of Plant Ecology at the same university. Species were classified into families, according to the Angiosperm Phylogeny Group III system [25].We compiled all species present in the inventories to undertake the floristic composition analysis. We carried out the analysis by preparing a binary database (presence/absence), containing the tree species listed in each fragment. We only considered individual trees identified at the species level in this database composition. For the Alpha diversity evaluation, we used the Shannon diversity index (H′) and the Pielou evenness index (J′).We used the binary database for the measurement of richness analysis, and also for the total number of species projection, we used first- and second-order, nonparametric jackknife estimators, in addition to Chao and Chao 2 estimators, which were capable of projecting total species richness from the samples of species richness [26], with 5,000 randomizations. We conducted the analysis using the EstimateS 8.0 program [27].


## 2.3. Multivariate Analyses

We did similarity and sorting analysis utilizing the FITOPAC SHELL 1.6.4 program [28], using an absolute density matrix for the species of ten sites, considering only those species with two or more occurrences, since species that had just one occurrence did not contribute to the floristic site ordering for floristic similarity. For categorical floristic data (presence and absence), we analyzed the similarity between sites, using the same absolute density matrix, transformed into presence/absence. We used the Sørensen similarity coefficient [29] and the unweighted pair group method with arithmetic mean (UPGMA) for a dendrogram graphical representation.We applied multivariate analysis to quantitative tree species floristic data (abundance) present in all the compared fragments. For this, we realized a data ordination by using the detrended correspondence analysis (DCA, [30]). In addition, to define predominantly the indicator and preferred species of the floristic groups, based on frequency and density (species with n≥5 individuals), we used dichotomous hierarchical division using TWINSPAN (two-way indicator species analysis, [31]), from an absolute data matrix and its frequency at the 10 sites, with a cut level of 0, 2, 5, and 10. These analyses were made by PC-ord for Windows program version 4.0 [32].


## 3. Results

A total of 242 species, distributed in 165 genera and 58 families, were found in the SSF (Table2). Families with a higher species richness were Fabaceae (sensu lato) (38 species), subdivided into Fabaceae Faboideae (20), Fabaceae Mimosoideae (11), Fabaceae Caesalpinioideae (5) and Fabaceae Cercideae (2), Myrtaceae (20 species), Rubiaceae (13), Annonaceae (11), Moraceae (10), Lauraceae (9), Meliaceae (9), and Malvaceae (8). These eight families showed a great contribution to the regional tree diversity, covering 48.8% of the species. Twenty-six families were represented by only one species. Annonaceae, Apocynaceae, Combretaceae, Fabaceae, Mimosoideae, Fabaceae, Faboideae, Lauraceae, Myrtaceae, Meliaceae, Rubiaceae, Salicaceae, Sapindaceae, and Sapotaceae were found at all ten studied sites.Table 2
Number of families and species, Shannon diversity index (H′), and Pielou evenness index (J′) from ten sites of seasonal semideciduous forest in southeastern Brazil.
SiteFamiliesSpeciesH′J′132783,4420,79238983,970,866327502,9240,747434883,2750,733533793,3660,768637863,7050,832737733,4710,809836983,7780,8249381033,8680,8361041883,5090,784Total582424,6160,840Most well-represented genera are in Fabaceae Faboideae (13), Rubiaceae (13), Myrtaceae (10), Annonaceae (8), and Euphorbiaceae, Fabaceae Mimosoideae, and Malvaceae, with seven genera each. Approximately 30% of families were represented by only one genus. The best represented genera in terms of species number wereAspidosperma, Machaerium, and Ficus, with seven species each, followed by Ocotea, Cordia, Inga, Trichilia, and Casearia with four species each.The total species richness, designed by jackknife estimators 1 and 2 and Chao 1 and 2 estimators, showed a similar pattern (273, 284, 285, and 268 species, resp.). Results suggest high regional tree species richness. The 242 species found approximates of richness designed for estimators, demonstrating sampling sufficiency among the ten hectares studied (Figure2).Figure 2
Sampling sufficiency designed by “jackknife” estimator for the ten sites of seasonal semideciduous forest in southeastern Brazil. Dashed line: standard deviation.The Shannon’s diversity index (H′) for each site showed diversity values between 2.92 and 3.97, with the Pielou’s evenness index (J′) between 0.73 and 0.87 (Table 2). However, when we considered the ten sites as a single sample, Shannon’s diversity index (H′) was 4.62, and Pielou’s evenness index was 0.84. This value can be attributed to the sampling covering quite heterogeneous sites, allowing differences in remnant structure and floristic composition and, consequently, increasing beta diversity.OnlyCopaifera langsdorffii and Hymenaea courbaril were presented with the highest frequency in distribution, reaching 100% of occurrence at the sites (Table 3). However, 75 species occurred in at least five studied fragments, highlighting Cordiera sessilis, Apuleia leiocarpa, Casearia gossypiosperma, Cheiloclinium cognatum, Ixora brevifolia, Luehea grandiflora, Protium heptaphyllum,  Sweetia fruticosa, and Terminalia glabrescens which occurred in nine sites, and can be indicated as characteristic SSF species (Table 3). On the other hand, 31.8% (77) of species occurred at only one site.Table 3
Species list sampled in ten sites of seasonal semideciduous forest of southeastern Brazil. NI = number of individuals; RF = frequency in the ten studied fragments; *First record for the Triangulo Mineiro region, **First record for the Minas Gerais state in seasonal semideciduous forests, according [11].
Families/SpeciesNIRF (%)AnacardiaceaeAstronium fraxinifolium Schott ex Spreng.1840Astronium nelson-rosae Santin25760Lithraea molleoides (Vell.) Engl.920Myracrodruon urundeuva Allemão4240Tapirira guianensis Aubl.3720Tapirira obtusa (Benth.) J.D.Mitch.8550AnnonaceaeAnnona cacans Warm.2950Annona montana Macfad.*110Cardiopetalum calophyllum Schltdl.640Duguetia lanceolata A. St.-Hil.22260Guatteria australis A. St.-Hil.*2810Porcelia macrocarpa (Warm.) R. E. Fr.*110Rollinia sylvatica (A. St.-Hil.) Mart.530Unonopsis lindmanii R. E. Fr.10240Xylopia aromatica (Lam.) Mart.3160Xylopia brasiliensis Spreng.3740Xylopia sericea A. St.-Hil.110ApocynaceaeAspidosperma cuspa (Kunth) S. F. Blake ex Pittier1010Aspidosperma cylindrocarpon Müll. Arg.2540Aspidosperma discolor A. DC.*29450Aspidosperma olivaceum Müll. Arg.810Aspidosperma parvifolium A. DC.*2850Aspidosperma polyneuron Müll. Arg.830Aspidosperma subincanum Mart. ex A. DC.1950AquifoliaceaeIlex cerasifolia Reissek310AraliaceaeAralia warmingiana (Marchal) J. Wen1230Dendropanax cuneatus (DC.) Decne. & Planch.1420Schefflera morototoni (Aubl.) Maguire et al.2980ArecaceaeAcrocomia aculeata (Jacq.) Lodd. ex Mart.510AsteraceaePiptocarpha macropoda Baker630BignoniaceaeHandroanthus serratifolia (Vahl) Nicholson2270Jacaranda cuspidifolia Mart. ex A. DC.220Jacaranda macrantha Cham.*420Tabebuia impetiginosus (Mart. ex DC.) Mattus220Tabebuia roseoalba (Ridl.) Sandwith1320BoraginaceaeCordia alliodora (Ruiz & Pav.) Oken**110Cordia sellowiana Cham.5250Cordia superba Cham.1310Cordia trichotoma (Vell.) Arrab. ex Steud.520BurseraceaeProtium heptaphyllum (Aubl.) Marchand28290CannabaceaeCeltis iguanaea (Jacq.) Sarg.3060Trema micrantha (L.) Blume320CardiopteridaceaeCitronella paniculata (Mart.) R.A.Howard410CaricaceaeJacaratia spinosa (Aubl.) A. DC.420CelastraceaeCheiloclinium cognatum (Miers.) A. C. Sm.40790Maytenus floribunda Reissek*7160Maytenus robusta Reissek410Maytenus sp.510Salacia elliptica (Mart. ex Schult.) G. Don110ChrysobalanaceaeHirtella glandulosa Spreng.5140Hirtella gracilipes (Hook. f.) Prance7250Hirtella racemosa Lam.1110ClusiaceaeCalophyllum brasiliense Cambess.110Garcinia brasiliensis Mart.6460CombretaceaeTerminalia argentea (Cambess.) Mart.210Terminalia glabrescens Mart.20290Terminalia phaeocarpa Eichler5660CunoniaceaeLamanonia ternata Vell.1220EbenaceaeDiospyros hispida A. DC.10850ElaeocarpaceaeSloanea monosperma Vell.1940ErythroxylaceaeErythroxylum daphnites Mart.610Erythroxylum deciduum A. St.-Hil.310EuphorbiaceaeAcalypha gracilis (Spreng.) Müll. Arg.**720Alchornea glandulosa Poepp. & Endl.2030Mabea fistulifera Mart.2510Maprounea guianensis Aubl.3240Micrandra elata Müll. Arg.11810Pera glabrata (Schott) Poepp. ex Baill.1220Sapium glandulosum(L.) Morong530Fabaceae caesalpinoideaeApuleia leiocarpa (Vogel) J. F. Macbr.11490Cassia ferruginea (Schrad.) Schrad. ex DC.930Copaifera langsdorffii Desf.155100Hymenaea courbaril L.119100Peltophorum dubium (Spreng.) Taub.*220Sclerolobium paniculatum Benth.310Fabaceae cercideaeBauhinia rufa (Bong.) Steud.940Bauhinia ungulata L.*2050Fabaceae faboideaeAndira fraxinifolia Benth.720Andira ormosioides Benth.*110Centrolobium tomentosum Guillem. ex Benth.110Dipteryx alata Vogel520Lonchocarpus cultratus (Vell.) Az.-Tozzi & H. C. Lima1130Machaerium acutifolium Vogel730Machaerium brasiliense Vogel6970Machaerium hirtum (Vell.) Stellfeld2530Machaerium nyctitans (Vell.) Benth.210Machaerium opacum Vogel110Machaerium stipitatum (DC.) Vogel2060Machaerium villosum Vogel6260Myroxylon peruiferum L. f.110Ormosia arborea (Vell.) Harms2370Platycyamus regnellii Benth.5030Platypodium elegans Vogel3270Pterodon emarginatus Vogel210Sweetia fruticosa Spreng.6990Vatairea macrocarpa (Benth.) Ducke110Zollernia ilicifolia (Brongn.) Vogel2140Fabaceae MimosoideaeAcacia polyphylla DC.3770Albizia niopoides (Spruce ex Benth.) Burkart2330Albizia polycephala (Benth.) Killip ex Record510Anadenanthera colubrina (Vell.) Brenan6720Calliandra foliolosa Benth.510Enterolobium contortisiliquum (Vell.) Morong940Inga laurina (Sw.) Willd.950Inga marginata Willd.1010Inga sessilis (Vell.) Mart.*4460Inga vera Willd.8440Piptadenia gonoacantha (Mart.) J. F. Macbr.16750LacistemataceaeLacistema aggregatum (P. J. Bergius) Rusby**320LamiaceaeAegiphila sellowiana Cham.1150Vitex polygama Cham.620LauraceaeCryptocarya aschersoniana Mez21270Endlicheria paniculata (Spreng.) J. F. Macbr.310Nectandra cissiflora Nees4430Nectandra megapotamica (Spreng.) Mez2950Nectandra membranacea (Sw.) Griseb.*8140Ocotea corymbosa (Meisn.) Mez13670Ocotea minarum (Nees) Mez410Ocotea pulchella Mart.810Ocotea spixiana (Nees) Mez5140LecytidaceaeCariniana estrellensis (Raddi) Kuntze5170LythraceaeLafoensia densiflora Pohl110MalpiguiaceaeByrsonima laxiflora Griseb.1240MalvaceaeApeiba tibourbou Aubl.430Ceiba speciosa (A. St.-Hil.) Ravenna1940Eriotheca candolleana (K. Schum.) A. Robyns2850Guazuma ulmifolia Lam.4950Luehea divaricata Mart.620Luehea grandiflora Mart. & Zucc.19990Pseudobombax tomentosum (Mart. & Zucc.) A. Robyns320Quararibea turbinata (Sw.) Poir.*510MelastomataceaeMiconia cuspidata Mart. ex Naudin110Miconia latecrenata (DC.) Naudin1030Miconia minutiflora (Bonpl.) DC.*710MeliaceaeCabralea canjerana (Vell.) Mart.740Cedrela fissilis Vell.1640Guarea guidonia (L.) Sleumer2350Guarea kunthiana A. Juss.1920Trichilia catigua A. Juss.16580Trichilia claussenii C. DC.13020Trichilia elegans A. Juss.5570Trichilia pallida Sw.2870MonimiaceaeMollinedia widgrenii A. DC.630MoraceaeFicus clusiifolia Schott*210Ficus guaranitica Chodat640Ficus obtusiuscula (Miq.) Miq.110Ficus pertusa L. f.*110Ficus trigona L. f.320Ficus sp1110Ficus sp 2110Maclura tinctoria (L.) Steud.430Pseudolmedia laevigata Trécul520Sorocea bonplandii (Baill.) W. C. Burger et al.940MyristicaceaeVirola sebifera Aubl.12780MyrtaceaeCalyptranthes clusiifolia O. Berg530Calyptranthes widgreniana O. Berg720Campomanesia guazumifolia (Cambess.) O. Berg110Campomanesia velutina (Cambess.) O. Berg9370Eugenia florida DC.19050Eugenia involucrata DC.4240Eugenia ligustrina (Sw.) Willd.2730Eugenia subterminalis DC.*2020Gomidesia lindeniana O. Berg110Myrcia splendens (Sw.) DC.1160Myrcia tomentosa (Aubl.) DC.940Myrciaria glanduliflora (Kiaersk.) Mattos & D. Legrand**10640Myrciaria tenella (DC.) O. Berg210Psidium longipetiolatum D. Legrand**210Psidium rufum DC.1240Psidium sartorianum (O. Berg) Nied.4150Siphoneugena densiflora O. Berg13360Syzygium jambos (L.) Aston.*110Myrtaceae 1110Myrtaceae 2110NyctaginaceaeGuapira opposita (Vell.) Reitz2810Guapira venosa (Choisy) Lundell5440Neea hermaphrodita S. Moore**1210OchnaceaeOuratea castaneifolia (DC.) Engl.1250OlacaceaeHeisteria ovata Benth.11360OleaceaeChionanthus trichotomus (Vell.) P. S. Green310OpiliaceaeAgonandra brasiliensis Miers ex Benth. & Hook.2450PhyllanthaceaeMargaritaria nobilis L. f.2770Phyllanthus acuminatus Vahl210PiperaceaePiper amalago L.410Piper arboreum Aubl.210PolygonaceaeCoccoloba mollis Casar.940PrimulaceaeArdisia ambigua Mez2530Myrsine coriacea (Sw.) Roem. & Schult.210Myrsine leuconeura Mart.220Myrsine umbellata Mart.1520ProteaceaeRoupala brasiliensis  Klotzsch3180RhaminaceaeRhamnidium elaeocarpum Reissek3450RubiaceaeAmaioua guianensis Aubl.3540Chomelia pohliana Mull. Arg.1440Cordiera sessilis (Vell.) Kuntze40490Coussarea hydrangeifolia (Benth.) Müll. Arg.3260Coutarea hexandra (Jacq.) K. Schum.2170Faramea hyacinthina Mart.4350Genipa americana L.110Guettarda viburnoides Cham. & Schltdl.2950Ixora brevifolia Benth.13190Machaonia brasiliensis (Hoffmanss. ex Humb.) Cham. & Schltdl.*210Rudgea viburnoides (Cham.) Benth.1150Simira sampaioana (Standl.) Steyerm.*4770Tocoyena formosa (Cham. & Schltdl.) K.Schum.110RutaceaeGalipea jasminiflora (A. St.-Hil.) Engl.*14210Metrodorea nigraA. St.-Hil.1020Metrodorea stipularis Mart.610Pilocarpus spicatus A. St.-Hil.*110Zanthoxylum riedelianum Engl.1130SalicaceaeCasearia gossypiosperma Briq.17290Casearia grandiflora Cambess.21840Casearia rupestris Eichler810Casearia sylvestris Sw.6560Prockia crucis P. Browne ex L.520Xylosma prockia (Turcz.) Turcz.*110SapindaceaeAllophylus edulis (A. St.-Hil., Cambess. & A.Juss.) Radlk.110Allophylus racemosus Sw.830Cupania vernalis Cambess.7880Dilodendron bipinnatum Radlk.1020Magonia pubescens A. St.-Hil.210Matayba elaeagnoides Radlk.**3940Matayba guianensis Aubl.10570SapotaceaeChrysophyllum gonocarpum (Mart. & Eichler) Engl.6940Chrysophyllum marginatum (Hook. & Arn.) Radlk.16120Micropholis venulosa(Mart. & Eichler) Pierre6130Pouteria gardneri (Mart. & Miq.) Baehni4270Pouteria torta (Mart.) Radlk.12880SiparunaceaeSiparuna guianensis Aubl.40770StyracaceaeStyrax camporum Pohl3550SymplocaceaeSymplocos pubescens Klotzsch ex Benth.*810UrticaceaeCecropia pachystachya Trécul1130Urera baccifera (L.) Gaudich. ex Wedd.1010VerbenaceaeAloysia virgata (Ruiz & Pav.) A. Juss.320VochysiacaeaeCallisthene major Mart.6240Qualea dichotoma (Mart.) Warm.530Qualea jundiahy Warm.*3960Vochysia magnifica Warm.11430Vochysia tucanorum Mart.510The floristic similarity analysis between sites showed a similar pattern in seven of the ten sites examined (Figure3). Accordingly, there was the formation of a floristically cohesive group (Group 1), where sites 3, 6, 7, 8, 9, and 10 were presented with values exceeding 0.5, indicating sites that were floristically similar. Also, a second group was formed with sites 1 and 4, whereas site 2 was floristically different from all the other sites (Figure 3).Figure 3
Dendrogram of similarity (Sørensen coefficient) produced by cluster analysis (UPGMA connection method) of tree species composition among the ten sites of seasonal semideciduous forest in southeastern Brazil.Detrended correspondence analysis, DCA, presented eigenvalues of 0.61 and 0.25 in the two first ordination axes, explaining about 85% of the total data variation (Figure4). The diagram demonstrated a large group formed from seven sites. Structural ordination, on the left, contemplates the same sites forming Group 1 by grouping analysis. These seven sites indicate the floristic pattern representative of the studied SSF. The second DCA axis was associated strongly with the sampled fragments’ conservation degree. The group formed on the center left is characterized by intermediate conservation stages, while other sites on the top right are characterized by more advanced conservation stages (Group 2). On the lower right is the initial stage (site 2). Therefore, the three fragments on the right do not form a cohesive group. In addition, these three sites are those that are more distant from each other. Thus, the structural floristic similarity of the seven areas above may have been established on a geographical position basis. The division made by TWINSPAN corroborated the ordination results by DCA and the Sørensen coefficient (Figure 3).Figure 4
Ordination diagram in first two axes of detrended correspondence analysis (DCA) of ten sites of seasonal semideciduous forest in southeastern Brazil. Symbols correspond to floristic groups 1 (▵), 2 (•), and 3 (o).The first division by TWINSPAN separated the seven SSF representative sites in this region from the three other fragments, owing to the absence ofSiparuna guianensis, a species regarded as an indicator, which only occurs in the group formed on the other side of the dichotomy (Figure 5). In the second division, sites 3 and 8 were separated from the other fragments (Figure 5). The lower levels of division by TWINSPAN do not reveal new groups that make sense.Figure 5
Classification by TWINSPAN of ten sites of seasonal semideciduous forest in southeastern Brazil.


## 4. Discussion

Studies conducted in areas of SSF in Brazil presented Fabaceae, Myrtaceae, Rubiaceae, Annonaceae, Lauraceae, and Meliaceae as the families with greater species richness [33–36]. In São Paulo state SSF, as well as the greater richness of families found in this study, there is also an emphasis on Melastomataceae and Solanaceae [37, 38]. In northeastern Brazil, the most prominent families in terms of species number in SSF sites are Fabaceae Mimosoideae, Euphorbiaceae, Fabaceae Faboideae, Myrtaceae, and Rubiaceae [39]. The pattern in families and genera richness found here corroborates that described by Oliveira Filho and Fontes [40] for SSF domains in southeastern Brazil, with significant tree species richness in Fabaceae (all subfamilies), Lauraceae, Myrtaceae, Moraceae, and Rubiaceae and genres Aspidosperma, Ficus, Machaerium, and Ocotea.Copaifera langsdorffii and H. courbaril are wide-ranging adaptive species, occurring in various forest formations of the Cerrado region, as well as in other geographical provinces in Brazil and are, therefore, considered to be habitat generalists [41]. Apuleia leiocarpa and Luehea grandiflora are also among the most frequent species of SSF, according to a study presented by Ferreira Júnior et al. [42], which brought together 15 studies in southeastern Brazil. The tree species composition studied in SSF showed a relationship with lowland seasonal forests of Brazil’s eastern Minas Gerais state, based on the indicator species analysis made by Oliveira-Filho and Fontes [40]. Of the 57 species identified by these authors as eastern Minas Gerais region indicators, 36 (63.1%) were recorded in the sample sites presented here. This data corroborates the idea that interior SSF fragments may have a floristic connection with the Atlantic forest that is able to expand its distribution in sites with strong seasonality by means of gallery forests [43].The presence of unique species to each location highlights the heterogeneity between samples (sites), reflected in increased beta diversity. We should point out that the limited number of individuals in some populations may impair the biological conservation of many species, causing serious difficulties for their preservation. However, some species, such asGalipea jasminiflora and Micrandra elata, occurred in only one fragment, but with a high density. This observation acquires relevance in terms of plant population conservation. The conservation of the remaining forest, with different structures and consequent higher beta diversity, can be a relevant parameter to the decision for choosing priority areas for conservation in SSF [44].Diversity values are among those frequently found for SSF and Atlantic rainforest, which generally vary between 3.2 and 4.2 [45]. However, they are lower than those found in other tropical forests [46]. The lower values for evenness found in fragments indicate a relatively high concentration in density of a small number of species, which dominate the tree community. The predominance of a few species, in number or biomass in a community (also known as ecological dominance), is not uncommon in tropical forests [47].A variation in similarity values occurs as a result of different conditions in the use and historic occupation of each fragment and acts as an important force capable of modifying plant communities through spatial and temporal heterogeneity, thus determining the community composition and structure [16, 48]. The separation of site 2 from other areas, along with Group 2, can be related to different stages of forest succession. Site 2 presents in an initial successional stage owing to an intense human processes. This fragment, although situated in the countryside, reveals recent historical disturbance as a result of selective logging and the presence of cattle, and the surrounding matrix is formed entirely by agricultural sites [49]. Selective logging enables the creation of gaps within the fragment and the establishment of pioneering species. As Whitmore states [47, 50], pioneer trees and shrubs need high light and temperature intensities for seed germination and seedling establishment and growth. Group 2 (sites 1 and 4) is formed by the more well-preserved fragments among those studied and is characterized by the presence and dominance of individuals with a large basal area. In fragment 4, for example, Micrandra elata was sampled with a density of 118 ind·ha−1 and a basal area of 24.51 m2·ha−1 [51], whereas in fragment 1, Psidium sartorianum was the species with the highest dominance [52].Although the floristic similarity between the fragments can be related to the geographical proximity, as already reported by MaCdonald et al. [53], we verified that similarity relations between studied sites are established mainly as a result of the community successional stage. This same pattern was also found by Durigan et al. [17]; that is, within the same vegetal formation, communities at similar stages of the successional process tend to have similar flora.This analysis showed high beta diversity of the studied SSF arboreal flora, mainly as a result of the coverage of heterogeneous areas in relation to fragments at a successional stage. The largest SSF sampling in the Cerrado domain led to the registration and distribution of several plant populations, which had previously only been described for the Atlantic forests  domain, demonstrating not only a lack of studies like this, but also corroborating the idea of strong floristic connections with rainforests in the east of the country [40].The fragmentation process started in the 1970s in the studied region of Brazil, especially as a result of the incentive given to landowners by the public authority for the advancement of occupied areas for agricultural and livestock activities, which had a direct consequence for the formation of many smaller forest fragments. Fragmentation possibly created similar processes in forests’ successional development, which has conditioned a floristic pattern as found for seven of the ten sites surveyed.



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*Source: 537269-2011-07-06.xml*