Evolutionary fingerprint, phylogenetic and forest structure of tropical montane Atlantic cloud forests along an elevation gradient

Environmental conditions can change markedly over geographical distances along elevation gradients,making them natural laboratories to study the processes that structure communities.This work aimed to assess the influences of elevation on Tropical Montane Cloud Forest plant communities in the Brazilian Atlantic Forest,a historically neglected ecoregion.We evaluated the phylogenetic structure,forest structure(tree basal area and tree density)and species richness along an elevation gradient,as well as the evolutionary fingerprints of elevation-success on phylogenetic lineages from the tree communities.To do so,we assessed nine communities along an elevation gradient from 1210 to 2310 m a.s.l.without large elevation gaps.The relationships between elevation and phylogenetic structure,forest structure and species richness were investigated through Linear Models.The occurrence of evolutionary fingerprint on phylogenetic lineages was investigated by quantifying the extent of phylogenetic signal of elevation-success using a genus-level molecular phylogeny.Our results showed decreased species richness at higher elevations and independence between forest structure,phylogenetic structure and elevation.We also verified that there is a phylogenetic signal associated with elevation-success by lineages.We concluded that the elevation is associated with species richness and the occurrence of phylogenetic lineages in the tree communities evaluated in Mantiqueira Range.On the other hand,elevation is not associated with forest structure or phylogenetic structure.Furthermore,closely related taxa tend to have their higher ecological success in similar elevations.Finally,we highlight the fragility of the tropical montane cloud forests in the Mantiqueira Range in face of environmental changes(i.e.global warming)due to the occurrence of exclusive phylogenetic lineages evolutionarily adapted to environmental conditions(i.e.minimum temperature)associated with each elevation range.

Understanding how environmental heterogeneity and elevation drives the distribution of woody communities across vegetation types within the campo rupestre in South America

The campo rupestre sensu lato is a vegetation type that occurs in South American mountains,supports a distinctive flora characterized by high rates of endemism,high herbaceous species richness and often-neglected but also species-rich of the arboreal stratum.We aimed to investigate how environmental factors and elevation are associated with the distribution and diversity of woody species in different rupestrian vegetation types across South America.Using a database of 2,049 woody species from 185 sites across four vegetation types within the campo rupestre,we assessed how the vegetation types were grouped according to their floristic composition and number of shared indicator species,as well as by using different beta diversity indices.The most important variables from a set of 27 variables(e.g.altitude,geo-edaphic and climatic)explaining species distribution were identified using redundancy analysis(RDA)and variation partitioning methods.The distribution of vegetation types was related to both environmental and spatial fractions,with a set of 17 variables retained(e.g.rockiness,grass cover and temperature seasonality as the most important variables).There was an association between the floristic composition of each vegetation type and the elevation range.Although the identified vegetation types are floristically related,they are distinguished by exclusive and habitat-specialist woody species.This uniqueness of vegetation types should be considered in terms of complementarity for the conservation of campos rupestres.

Small-scale edaphic heterogeneity as a floristic-structural complexity driver in Seasonally Dry Tropical Forests tree communities

Our work aimed to test the hypothesis that soil microscale heterogeneity act as a community ecological driver,increasing diversity and promoting structural shifts on the Seasonally Dry Tropical Forest(SDTF)tree community.We evaluated the relationship between microscale edaphic variations and floristic–structural patterns of tree communities in a SDTF fragment located in the southern end of the Brazilian Caatinga domain.Vegetation and soil data were obtained through 27 sample units of 400 m2(20 m 920 m),within each one we measured and identified at species level all arboreal individuals with Circumference at the Breast Height greater or equal to 10 cm,and also collected the soil samples.Through the data we evaluated soil variation influence on the tree community structural and floristic patterns trough generalized linear models.Soil explained the small-scale structural and floristic variations,contributing significantly to biomass,sprouting and to floristic relationships between sample units.It was also observed a possible relation of the result with the Caatinga domain biogeographic history,due the presence of Sedimentary Caatinga species,which are not expected for the study region.Soil plays an important role in driving small-scale complexity and diversity of SDTF,but we also suggest that Caatinga biogeographic events have influence on the high heterogeneity patterns.