Similar Floristic Composition Research Articles

Think globally and act locally: Assessing the environmental impacts of the Nigerian threatened native trees project

The environmental and socio-economic impacts of the Nigerian Threatened Native Trees Project are presented. This project conducted propagation trials and developed a freely downloadable online Manual of Tree Propagation (MTP) for 55 native tree species, training 146 local experts (32 women and 114 men) during the period (November 2015—December 2022). We used Google Analytics and interviews to assess the impacts of this project from January 2018—July 2023 (iEcology). Results show that the MTP has been downloaded 1013 times, with the star apple Gambeya albida (76), gum tree Tetrapleura tetraptera (65) and bitter kola Garcinia kola (50) topping the list. These downloads were from 15 countries spread across the world. Interestingly, the seven African countries that downloaded the MTP are concentrated in the tropical belt with similar floristic composition. The native range of almost all the propagated species overlaps with these African countries, suggesting the adoption of our MTP, and practically demonstrating the conservation mantra of “think globally, act locally”. In addition, the MTP has been deployed for academic work (i.e., grey literature) and reforestation (e.g., covering c. 1200 ha in Nigeria). By revealing suitable propagation techniques and training local foresters, our approach could boost the utilization of native tree species for reforestation in Africa.

Association Of Shorea Platyclados With Dominant Trees In Martelu Purba Nature Reserve

Shorea platyclados, known to the public as Meranti Bukit, is one of the species whose existence S. platyclados Slooten ex Foxw. or what is known by the local name Meranti Bukit is a type of meranti tree that has fast growth and is recommended as a plant for forest and land rehabilitation activities. S. platyclados is threatened in nature and is included in the Near Threatened (NT) its category based on the IUCN Redlist. Conservation efforts are needed to better understand natural habitat conditions and increase the population of S. platyclados in nature with an ecological approach. An association is a common kind of community that is present in many places and occurs under similar circumstances.. Associations are characterized by having a similar floristic composition, having a uniform physiognomy, and their distribution having a unique habitat. Studies on plant associations around S. platyclados have yet to be revealed so a more in-depth ecological analysis is needed to determine the relationship between S. platyclados and other plants around it. The purpose of this study was to analyze the association between S. platyclados and the dominant trees in the Martelu Purba Nature Reserve area. Using the 2x2 Contingency Table, association analysis was performed on the primary constituent species with an IVI of ≥10%.. The results of the analysis of the type of association between S.platyclados and the dominant tree showed positive for Charcoal and Akhirsap species, while for Modang, Beringin, and Kemenyan species negative association.

DIVERSITY OF EXOTIC SPECIES IN TWO URBAN FOREST PATCHES IN CURITIBA, PARANÁ

Urban forest patches (UFP) face challenges related to climate change and anthropic impacts on natural ecosystems and their biodiversity, mainly due to the presence of invasive exotic species. The objective of this research was to characterize the invasive flora of two urban forest patches located in Curitiba, Paraná. The research was conducted in the Papa João Paulo II and Gutierrez woods, located in Curitiba, Paraná. Ten sample plots of 20x30 m (600 m²) were installed, all individuals with DBH >15 cm were sampled, six in Papa João Paulo II, and four in Gutierrez. A floristic characterization was carried out in each plot, separating native and exotic species. The ecological indices of Shannon-Weaver Diversity, Pielou, Simpson and Jaccard Equability were calculated to quantify vegetation diversity. Floristic analyzes were carried out in an R ambient. Altogether, 546 tree individuals were measured, belonging to 61 species of 31 families. The mean values of the Shannon-Weaver and Pielou indices were higher in Bosque Gutierrez. There was low similarity in floristic composition between sample plots. There were statistically significant differences between the categories of variables, in relation to native and exotic species, and between UFP. The presence of native species still exceeds that of exotic and invasive alien species in both UFP. The exotic invasive species Ligustrum lucidum already has a worrying influence on the ecological sustainability of UFP. The evaluated UFP are going through the process of biotic homogenization in their floristic composition.

The Impact of Rotational Pasture Management for Farm-Bred Fallow Deer (Dama dama) on Fodder Quality in the Context of Animal Welfare

Extensive breeding of farmed cervids, similarly to other livestock, affects the vegetation of grasslands in different seasons. For this reason, the impact of the rotational grazing of fallow deer on the chemical and species composition of the pasture sward was assessed, along with the possibility of using these animals for grasslands conservation. The species composition of the pastures was analysed through the botanical-weight method. A quality index and mineral concentration test by inductively coupled plasma mass spectrometry were used to evaluate the feed. The highest proportion of valuable grasses, such as Dactylis glomerata, Poa pratensis and Lolium perenne, was recorded in the summer pens (65.7–66.1%), while the smallest proportion was recorded in the control area (46.1%). The estimated yield potential was relatively large, from 5.74 to 7.02 t ha−1 dry matter. The lowest total protein content occurred in the control area in the spring and autumn. The summer pens, including the sown one, had a better fodder quality, depending on the species composition. All pens were characterised by a high production potential and similar floristic composition, without the participation of undesirable plant species, which confirms the hypothesis that, under extensive grazing conditions, fallow deer can be used for grassland conservation.

Phytodiversity Estimation of High-altitude Pastureland Above Yonphula, Kanglung Gewog, Trashigang Dzongkhag

High altitude pasturelands (Tsamdro) are important grazing grounds of livestock in Bhutan. Pasturelands are degrading due to overgrazing and shrub encroachment along with climate change. The lack of floristic knowledge of such pastureland would mean permanent loss of phytodiversity if not studied timely. This floristic study was conducted for two seasons using quadrat method of vegetation analyses. Phytodiversity was determined using different biodiversity indices. A total of 83 species in 60 genera belonging to 35 families were recorded from the pastureland including two endemic species, Halenia elliptica D. Don and Viola bhutanica H. Hara. Asteraceae, Rosaceae and Gentianaceae are species rich families. Species indicated a high richness with 2.17, dominance index was 0.92 for species like Elsholtzia strobilifera (Benth) Benth, Swertia spp., Fragaria nubicola (Lindl. ex. Hook.f.) Lacaita, Potentilla sp., Trifolium repens L., Euphorbia griffithii Hook. f., and Plantago erosa Wall. The diversity value was 2.97, indicating low diversity with even distribution (0.91). Similarity index of 0.70 indicated fairly similar floristic composition in autumn and spring seasons. This study provides basic information on floristic composition and phytodiversity of pastureland, which can be incorporated for pastureland management and conservation.

Синтаксономия ксеропетрофитной растительности Южного Урала: союз Elytrigion pruiniferae all. nov.

Синтаксономия ксеропетрофитной растительности Южного Урала: союз Elytrigion pruiniferae all. nov.

Response of leaf morphological traits of relict-endemic Symplocos species (S. coccinea and S. speciosa) to elevation and abiotic fluctuations

Abiotic fluctuations in montane ecosystems trigger changes in the hydric functional traits of tree species. These variations are better recognized in tree species inhabiting montane humid ravine slopes with different elevation, as is the case of many areas across the Mexican Neotropical montane forests. Little is known about the response of tree towards elevation gradients and abiotic changes. In this study, we analyzed the leaf morphological variation of two rare and Mexican endemic Symplocos species (S. coccinea and S. speciosa) occurring eastern Mexico on sites with different microclimate and elevation but similar floristic composition. We quantified how the abiotic factors (i.e. canopy openness, soil temperature, soil moisture, and litter depth) and site elevation influence the leaf traits of these tree species. Symplocos coccinea (with toothed leaf margins) is adapted to high humid conditions and high canopy coverage, while S. speciosa (with almost entire leaf margins) is resilient to environments with moisture deficit and high temperatures. Process-based research with fine-spatial scales at montane ecosystems are needed to understand the resilience and morphological variations of montane tree species under climate change worldwide. In this study, we confirmed that the Symplocos leaf morphological traits (i.e. leaf length, leaf width, leaf shape index, leaf base angle and vein density) are strongly influenced by abiotic conditions (i.e. canopy openness, litterfall depth, soil moisture and soil temperature).

Vegetation response to environmental changes based on palynological research on the Middle Miocene lignite at the Jóźwin IIB open-cast mine (Konin region, central Poland)

Palynological research was performed on the first Mid-Polish lignite seam (MPLS-1) at the Jóźwin IIB open-cast mine. The extremely rich pollen assemblages allowed investigation of the development of phytogenic sedimentation and the succession of plant communities. The vegetation cover, representing peat accumulation and adjacent areas, was reconstructed in the homogeneous lignite seam. Despite the lack of clear macroscopic differences in the lignite lithology and a similar floristic composition, a similar succession of plant communities was observed in three repetitions in the profile. The plant communities described were grouped into five cycles. Changes in the succession resulted mainly from oscillations of the groundwater level. On the basis of the vegetation composition, the climatic conditions predominant during the peat-forming sedimentation were reconstructed. Climate changes are most precisely recorded in the mixed mesophilous forest community. Its floristic composition shows that the climate was warm-temperate and humid at that time. The lower part of the profile contains more taxa with high thermal requirements: Araliaceae, Mastixiaceae, Anacardiaceae, Hammamelidaceae, Cornaceae, Symplocaceae, Ilex , Itea , Engelhardia , etc. It is related to the Middle Miocene Climatic Optimum (MMCO). In the upper part of the profile, the vegetation composition reflects the beginning of a cooling trend. This is indicated by the reduced number of highly thermophilous taxa and the decreased taxonomic diversity of forest communities. The changing climatic and environmental conditions interrupted peat-bog sedimentation and caused termination of the development of thicker lignite seams.

Agroforestry systems of a Zapotec community in the Northern Sierra of Oaxaca, Mexico

Background: Agroforestry systems have cultural, economic, social, and biodiversity conservation significance and are essential for the subsistence of communities.
 Questions: Is there a difference in the richness, management and use of useful plants present in the agroforestry systems (home gardens, coffee plantations, and milpa)? What is the influence of sociodemographic factors on the distribution of traditional knowledge regarding plants of these systems?
 Site and years of study: Las Delicias, municipality of Juquila Vijanos, Sierra Norte of Oaxaca, Mexico, from January 2016 to May 2018.
 Methods: Visits to three agroforestry systems and semistructured interviews with 30 families to learn how they use the plants and to calculate the use value (UV) for each species. The similarity of floristic composition between agroforestry systems and the influence of sociodemographic factors (age, gender, schooling, economic activity and language) in the traditional plant knowledge was evaluated. The methods used were chi squared and proportions analyses, and a generalized linear analysis with Poisson distribution.
 Results: The three agroforestry systems consisted of 211 of useful plants; home gardens and coffee plantations had a greater similarity in floristic composition; the dissimilarity of the milpa agroecosystem is related to seasonality. The plants with higher UVs were those with multiple uses, and are found mainly in coffee plantations. Production in these spaces is complemented to satisfy the needs of the inhabitants. Gender and economic activity are factors that influence the distribution of traditional knowledge.
 Conclusion: Agroforestry systems provide a species richness differentiated for specific purposes but complementary to each other.

Динаміка різноманіття трав'яно-чагарничкового ярусу після суцільних рубань дубових лісів природного походження та створення культур дуба у вологих сугрудах Житомирського Полісся

Досліджено флористичний склад та видову подібність трав'яно-чагарничкового ярусу рослинних угруповань / фітоценозів різного віку на місці суцільно-лісосічних рубань субклімаксових дубових лісів природного походження та створення культур дуба на зрубах (Житомирське ОУЛМГ, ДП "Лугинське ЛГ", Дивлинське лісництво, ДП "Баранівське ЛМГ", Баранівське лісництво). На 36 ділянках виконано геоботанічні описи (вікові категорії: 1 рік, 2 роки, 3 роки; 7, 10, 20-120 років) та визначено видову подібність трав'яно-чагарничкового ярусу цих груп за індексом Сьоренсена-Чекановського. Виявлено, що на місці зрубів упродовж 1-3 років формуються динамічні рослинні угруповання зі залишками лісових видів та значною участю світлолюбних рудеральних і лучних видів. Після змикання крон молодого деревостану (після 10 років) флористичний склад та ценотична будова фітоценозів поступово відновлюються, і в лісових культурах дуба звичайного після 40 років параметри видового різноманіття є подібними до таких, характерних для вихідних субклімаксових ценозів. Починаючи з 10 років (періоду змикання крон), спостерігається висока видова подібність флористичного складу трав'яно-чагарничкового ярусу культур дуба з усіма віковими категоріями ценозів після змикання крон деревостану. Флористична подібність ценозів після періоду змикання з динамічними рослинними угрупованнями перших вікових груп є низькою. Ценотична будова лісових фітоценозів (ярусна, синузіальна) відновлюється після 30 років.

Habitat preference in the critically endangered yellow‐tailed woolly monkey (Lagothrix flavicauda) at La Esperanza, Peru

Habitat loss is one of the main threats to wildlife. Therefore, knowledge of habitat use and preference is essential for the design of conservation strategies and identification of priority sites for the protection of endangered species. The yellow-tailed woolly monkey (Lagothrix flavicauda Humboldt, 1812), categorized as Critically Endangered on the IUCN Red List, is endemic to montane forests in northern Peru where its habitat is greatly threatened. We assessed how habitat use and preference in L. flavicauda are linked to forest structure and composition. The study took place near La Esperanza, in the Amazonas region, Peru. Our objective was to identify characteristics of habitat most utilized by L. flavicauda to provide information that will be useful for the selection of priority sites for conservation measures. Using presence records collected from May 2013 to February 2014 for one group of L. flavicauda, we classified the study site into three different use zones: low-use, medium-use, and high-use. We assessed forest structure and composition for all use zones using 0.1 ha Gentry vegetation transects. Results show high levels of variation in plant species composition across the three use zones. Plants used as food resources had considerably greater density, dominance, and ecological importance in high-use zones. High-use zones presented similar structure to medium- and low-use zones; thus it remains difficult to assess the influence of forest structure on habitat preference. We recommend focusing conservation efforts on areas with a similar floristic composition to the high-use zones recorded in this study and suggest utilizing key alimentation species for reforestation efforts.

Inter-regional beta-diversity patterns of the woody flora of Greece

This study aimed to estimate and explain the compositional differentiation and observed beta-diversity (partitioned as turnover and nestedness) patterns of woody species in Greece. Specifically, the 13 phytogeographical regions of Greece were compared at three taxonomic levels: family, genus, and (sub-) species. In Greece, 565 woody taxa have been identified, which are classified into 224 genera and 85 families. Phytogeographical regions were grouped according to their similarity in floristic composition using cluster analysis. Dominant beta diversity gradients were detected using Mantel directional correlation tests applied at the three taxonomic levels. The 13 phytogeographical regions formed three groups; namely, the northern, central, and southern (Aegean Islands) regions. The taxonomic variation among the phytogeographical regions at the species level was related to a gradient of richness of widespread taxa and Balkan endemic taxa. Analysis at the taxonomic levels of species and genus produced similar results, yet, at the family level, floristic differences were less pronounced, with phytogeographical regions being aggregated in two groups: the southernmost island regions versus all other regions. Beta diversity was higher along a northwestern to southeastern gradient, which was related to a dominant climatic gradient throughout Greece. The partitioning of beta diversity between neighboring phytogeographical regions showed that species turnover was the dominant component; yet, some phytogeographical regions (e.g., Kiklades) were characterized by high nestedness. In conclusion, analysis of woody taxa provides different insights regarding the floristic variation of phytogeographical regions.

Floristic characteristics and affinities in Lao PDR, with a reference to the biogeography of the Indochina peninsula.

The flora of Laos is composed of 5,005 species in 1,373 genera and 188 families of seed plants. Floristic and geographical attributes of the flora were analyzed. Tropical floristic elements at the family and generic levels contributed a majority (62.23% of the families and 82.30% of the genera) of the flora, of which the dominant geographical elements were pantropical distribution (42.02% of families) and tropical Asian distribution (30.08% of genera). This revealed that the flora of Lao PDR is tropical in nature and has a conspicuously tropical Asian affinity. Compared with the neighbouring countries of the Indochina peninsula, the flora of Laos has similar floristic composition and geographical elements. The floras of these Indochinese countries have similarities of more than 77.84% at the generic level, which suggests that they compose an affiliated biogeographical region. However, the flora of Laos showed the highest similarity to the flora of Vietnam (92.13%), followed by Myanmar (86.01%) at the generic level, but has less East Asian and North Temperate elements than Vietnam, and less North Temperate elements than Myanmar. These differences among the compared countries could be explained by the extrusion of the Indochinese block with the uplift of the Himalayas.

Changes in terrestrial floras at the Triassic-Jurassic Boundary in Europe

One of the biggest mass extinctions took place at the Triassic-Jurassic Boundary. It affected both marine and terrestrial ecosystems, and caused the disappearance of many animal taxa, mostly marine ones. Its influence on floral changes has been widely discussed, with arguments offered for the sudden mass extinction of plants over vast areas, or, alternatively, for slow, less extensive changes. The aim of this study was to statistically verify changes in terrestrial plant composition during the TJB in Europe, and to examine the type and extent of these changes. Data from Polish localities, an interesting new addition to the floristic data from the TJB, were compared with those from other selected localities in Europe. The database contains 311 macroflora taxa from 106 localities (16 Polish) in 13 countries, grouped into 29 regions; and 571 microflora taxa from 105 localities (29 Polish) in 11 countries, grouped into 37 regions. The analysed data cover the period from the Anisian to the Toarcian stages.Range-based metrics for diversity dynamics were calculated to show trends in floral changes during the studied time interval, the focus being on the TJB. Due to strong disproportions in the number of localities and occurrences, the Rhaetian and the Hettangian stages were overrepresented. The warm and humid climate of those stages promoted plant diversity and led to the formation of numerous broad floodplains conducive to the preservation of remains (e.g. in coal). The patterns established by the raw data analyses were also assessed by applying a sampling standardisation procedure. Our results, based on accurate data from Poland and the rest of Europe, confirm and visualize a scenario in which there were no significant changes in terrestrial plant composition at the TJB. Hierarchical clustering suggests that local habitat conditions are the key factor in the grouping of localities with similar floristic composition, and that differences between floras are not associated with the time dimension (stages).

Identifying alien plants linkages between irrigated orchards and adjacent riparian habitats from a trait-based approach

Floodplains and crops are particularly susceptible to alien plant invasion, often leading to negative ecologic and economic impacts. As irrigated crops and riparian habitats are interconnected at the landscape scale, plant species of each habitat may be susceptible to colonizing the other. In order to avoid alien plant invasions of natural habitats and surrounding crops and to develop management practices to face this problem, it is not only essential to understand which traits favour the success of alien plants in irrigated crops and floodplains, but also whether a flow of species between these two habitats actually exists. With this aim, floristic surveys were carried out on riparian habitats (riparian forest, reedbed and muddy line) and on irrigated orchards at a gradient of distance from the river. Differences in weed management techniques applied in orchards were taken into account during the surveys. Plant diversity, composition and invasion levels were evaluated for each habitat and differences in floristic composition were interpreted in terms of functional traits. Natural habitats were well differentiated from crops in terms of native plants, but when considering alien plants, muddy line and flood irrigated orchards showed similar floristic composition. Alien plant community in the muddy line was a subset of that of flooded orchards and it was composed by C4 species, with clonal growth, perennial graminoids and water seed dispersal. This work proves that, unlike native species, alien species are shared between irrigated orchards and adjacent floodplains, which is favoured by a set of traits that allows them to colonize and establish new populations there. These results can help to develop strategies for preventing the establishment of alien plants in these habitats and to manage already present populations.

A Baseline Environmental Impact Assessment (EIA) of Proposed Sit for Thermal Desorption Unit (TDU) Waste Management Project in Rivers State, Nigeria: Floristic Composition Approach

This report describes the results of a wet and dry season ecological baseline impact assessment study based on the context of a proposed Thermal Desorption Unit (TDU) development project in Eteo Eleme, Rivers State. Thermal Desorption Unit project of the magnitude of a waste management project must always have some negative effects on the quality and quantity of the environment. Following an environment impact assessment (EIA) a series of mitigation measures must be put in place to minimize the intensity of the negative effect of the project on the environment. The paper seeks to assess through baseline data the envisaged impact of the project on the existing conditions of the biophysical environment, to appraise the possible risk to the environment and mitigation measures adopted. It uses a combination of standard procedures of integrated data sources to qualitatively and quantitatively assess the floristic profile of the project study area. The result highlights most of the biophysical impact variables that will have negative effect on the environment. However, the study site still maintains the status of abundance, richness and evenness with obvious similarity in floristic composition and forest structure to that in tropical forest elsewhere in the world. It is obvious that the Eteo vegetation system is gradually under ecological succession resulting to secondary vegetation system without proper articulation of its wealth of flora diversity, but with high flora diversity in rainy season than dry season. The useful application of phyto-sociological indices in determining the status of its vegetation complex in terms of species abundance, density, important value index, diversity and distribution pattern is being recorded in the Table for both wet and dry seasons. The paper emphasis the need for sound environmental commitments to the project and to appraise their implementation. A proper balance between the expected benefits from the project and cost implication can only be obtained through impact studies and careful monitoring.

Diversidad de plantas exóticas en áreas sometidas a distintos disturbios en el Parque Nacional Los Alerces, Chubut (Argentina)

La proporción de especies exóticas en un área protegida y su matriz aledaña está influenciada por disturbios naturales y antrópicos, como el uso de la tierra y el tráfico de visitantes al área, que potencian la susceptibilidad a invasiones. Se analizó cuali y cuantitativamente la diversidad de especies exóticas en áreas disturbadas del Parque Nacional Los Alerces, Chubut. Se seleccionaron dos sitios sometidos a cada uno de los siguientes disturbios: incendio, pastoreo y acampe, donde se utilizaron transectas de 50 m de longitud. En la ruta Nº 71 se establecieron transectas de 150 m paralelas al borde del camino y dispuestas cada 2 km. Se registró la composición florística y la abundancia relativa de todas las especies exóticas presentes y se estimó la diversidad. Para comparar los sitios con distinto tipo de disturbio en base a la composición florística y a la cobertura de las diferentes especies exóticas se realizó un Análisis de Correspondencia Detendenciado. Se registraron 67 especies, con diente de león (Taraxacum officinale), pasto ovillo (Dactylis glomerata), pasto miel (Holcus lanatus), vinagrillo (Rumex acetosella) y rosa mosqueta (Rosa rubiginosa) presentes en todos los sitios. Las áreas de incendio y acampe presentaron riqueza y diversidad similar, mientras acampe y pastoreo fueron semejantes en composición especifica. Se generó información básica para la detección y control de plantas exóticas dentro del parque, especialmente de aquellas consideradas invasoras.

Estudo fitossociológico de uma área de Caatinga na Estação Ecológica (ESEC) de Aiuaba, Ceará, Brasil

The goal of this work was to characterize the physiognomy and structure of the woody component of an area of caatinga vegetation in the Estacao Ecologica (ESEC) of Aiuaba, Ceara state, thereby contributing to the knowledge of the vegetation of semiarid northeastern Brazil. Fifty sampling plots (10x10m) were randomly established in a 1.5 hectare area, where stem diameter at soil level was ≥ 3 cm and height was ≥ 1 m. The survey results included 3,007 individuals from 47 species and 20 families. Fabaceae, Euphorbiaceae, Erythroxylaceae, Acanthaceae, Bignoniaceae and Rutaceae represented 66% of the species, and the first three families represented 63% of the total importance value. Croton argyrophylloides Mull. Arg., Pityrocarpa moniliformis Benth., Erythroxylum caatingae Plowman and Bauhinia cheilantha (Bong.) Steud. were the most important species. Average plant height was 4.51 m, with a maximum of 13 m; average stem diameter was 7.28 cm, with a maximum of 44.88 cm. The total basal area was 18.3 m2 ha-1. The plant community can be classified as a type of caatinga with shrubs and trees, presenting similar floristic composition to other caatinga vegetation in areas of sandy sediments, and to non-thorn deciduous vegetation (“carrasco”) situated in the Ibiapaba-Araripe Complex.

Environmental filters and patterns of tree regeneration in high altitude sub‐tropicalQuercus‐dominated forests

AbstractWe investigated how environmental variables explain patterns of tree regeneration in high altitude sub‐tropicalQuercus‐dominated forests by: (1) determining whether the seedling and sapling communities show non‐random spatial patterns of floristic composition; (2) identifying which environmental variables explain the observed patterns of floristic composition; (3) examining if similarity in floristic composition is related to similarity in environmental variables. We used data gathered in permanent plots established across 10 km in high altitude sub‐tropicalQuercus‐dominated forests. Our analyses consisted of unconstrained ordination analyses (Non‐metric Multidimensional Scaling) to characterize the spatial patterns of floristic composition; constrained ordination analyses (Canonical correspondence analysis) to assess the contribution of environmental variables in explaining patterns of floristic composition and, the simple and partial Mantel test to correlate the floristic composition similarity to environmental similarity. Our results provided evidence of non‐random spatial patterns of floristic distribution due to structured environmental filters such as canopy‐related variables, litter, grazing and aspect. Floristic compositional similarity did not depend on geographical distance between sites or on differences in their environment; therefore a number of plots were similar in floristic composition, in both seedlings and saplings, but have no environmental similarity.

Habitat specialization and phylogenetic structure of tree species in a coastal Brazilian white-sand forest

Aims The coastal Brazilian rainforest on white-sand (restinga) ranks among the most fragmented forest types in the tropics, owing to both the patchy distribution of sandy soils and widespread coastal development activities. Here we study the environmental and evolutionary determinants of a forest tree assemblage at a single restinga forest in Southeastern Brazil. We also explore the ability of competing hypotheses to explain the maintenance of species diversity in this forest type, which includes contrasting extremes of edaphic conditions associated with flooding stress. Methods The study was conducted in a white-sand forest permanent plot of 10.24 ha on the coastal plain of Southeastern Brazil. This plot was divided into 256 quadrats of 20 × 20 m, whic h were classified into two main edaphic habitats (flooded and drained). Trees with a diameter ≥1 cm at breast height were identified. W e assembled DNA sequence data for each of the 116 morphospecies recognized using two chloroplast markers (rbcL and matK). A phylogenetic tree was obtained using the maximum likelihood method, and a phylogenetic distance matrix was produced from an ultrametric tree. We analyzed similarity in floristic composition and structure between habitats and related them to cross-plot distances using permutation procedures. Null model torus shift simulations were performed to obtain a statistical significance level for habitat association for each species. The phylogenetic structure for the two habitats and for each 20 × 20 m quadrat w as calculated using the mean phylogenetic distance weighted by species abundance and checked for significance using the standardized effect size generated by 5000 randomizations of phylogenetic tip labels.