Savanna Mosaic Research Articles

Chimpanzee (Pan troglodytes verus) Density and Environmental Gradients at Their Biogeographical Range Edge

Identifying ecological gradients at the range edge of a species is an essential step in revealing the underlying mechanisms and constraints that limit the species’ geographic range. We aimed to describe the patterns of variation in chimpanzee (Pan troglodytes verus) density and habitat characteristics perpendicular to the northern edge of their range and to investigate potential environmental mechanisms underlying chimpanzee distribution in a savanna–mosaic habitat. We estimated chimpanzee densities at six sites forming a 126-km latitudinal gradient at the biogeographical range edge of the western chimpanzee in the savanna–mosaic habitats of southeastern Senegal. To accompany these data, we used systematically placed vegetation plots to characterize the habitats at each site for habitat heterogeneity, tree density and size, and floral assemblages, among other variables. We found that both biotic and abiotic factors are potential determinants of the chimpanzee range limit in this ecoregion. Specifically, chimpanzee-occupied landscapes at the limit had smaller available floral assemblages less habitat heterogeneity, and contained fewer closed canopy habitats in which chimpanzees could seek refuge from high temperatures than in landscapes farther from the range limit. This pattern was accompanied by a decline in chimpanzee density with increasing proximity to the range limit. Our results provide several indications of the potential limits of food species diversity, thermal refuge, and water availability to the chimpanzee niche and the implications of these limits for chimpanzee biogeography, especially in the face of climate change predictions, as well as for species distributional modeling more generally.

Spatiotemporal Variation in Bonobo (Pan paniscus) Habitat Use in a Forest–Savanna Mosaic

Understanding the ecological and behavioral variation of primates is central to improving conservation strategies. Studies of chimpanzees (Pan troglodytes) have shown marked behavioral variability across a wide range of habitats. By comparison, bonobos (Pan paniscus) occur mainly in continuous forest sites, and socioecological models explaining behavioral differences between the two species are based on the assumption that bonobo habitat is richer and more stable than chimpanzee habitats. The objective of this study was to assess bonobo ecology in a forest–savanna mosaic. We specifically explored 1) bonobo home range size, habitat use, and dietary composition; 2) forest fragmentation in a bonobo community’s home range; and 3) seasonality of dietary diversity, habitat use, and spatial distribution. Using 2 years of observational data on location, habitat type, and dietary composition, we found that the bonobo community's home range size, density, and dietary diversity were similar to those observed in continuous forest sites. Bonobos used areas with lower forest fragmentation than the surrounding areas and preferentially spent time in forested habitats. During the dry season, bonobos consumed a lower diversity of fruit species, spent more time in sparse forest with Marantaceae understory, and were closer to the seasonal center of their home range than during the rainy season. Our results contribute to our understanding of behavioral variation in bonobos and suggest that forest–savanna mosaic is valuable to bonobo conservation.

Mohammed Armani.

Mohammed Armani.

Estudios fitosociológicos en el gran Chaco: estructura, composición florística y variabilidad del bosque de Schinopsis balansae en el Chaco húmedo boreal, Paraguay

Se presenta la descripción del bosque de Schinopsis balansae que incluye un análisis de su estructura, composición y variabilidad florística. El sitio de muestreo se situó dentro del mosaico bosques-sabanas palmares en el Chaco húmedo. Se determinaron datos cuantitativos para el cálculo del Índice de Valor de Importancia, que incluyó la abundancia, frecuencia y dominancia de las especies. Se calculó el índice de Diversidad del mismo y el valor obtenido fue comparado con otros bosques de la región. Los resultados indican que el bosque es un complejo de Fabaceae-Anacardiaceae-Arecaceae, con asociaciones edafobotánicas muy características y que florísticamente se trata de un bosque mixto y transicional con otras formaciones vegetales de América del Sur.

Dietary Ecology of the Nigeria–Cameroon Chimpanzee (Pan troglodytes ellioti)

Examining the diets of primate populations inhabiting different habitat types could be useful in understanding local adaptation and divergence between these populations. In Cameroon, the Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) is subdivided into two genetically distinct populations that occupy different habitat types; one occurs in forests to the west and the other in a forest–woodland–savanna mosaic (ecotone) in the center of the country. We used macroscopic fecal sample assessment to investigate dietary differences in relation to monthly fruit availability among P. t. ellioti communities in both habitat types: at Ebo Forest (rainforest) and Mbam and Djerem National Park (ecotone). We collected data simultaneously across three sites: Bekob and Njuma (rainforest) and Ganga (ecotone) from January 2016 to December 2017. In the dry season, fruits were the most important dietary component at Bekob and Njuma, while nonfruit plant material (leaves, pith, and bark) were most important at Ganga. In the wet season, the proportion of fruits in the diet was greatest at Ganga, while nonfruit plant material dominated chimpanzee diets at Bekob and Njuma. Chimpanzees at Bekob ate more fruits from introduced and secondary forest plant species than those at Njuma and Ganga, especially during periods of fruit scarcity. Animal consumption was higher at Ganga and was inversely associated with fruit consumption. These observations link habitat diversity to differences in feeding ecology among genetically distinct populations of P. t. ellioti. We speculate that dietary differences reflect broader socioecological variation between these populations, and collectively, that these factors promote intraspecific divergence.

Small mammal diversity is higher in infrequently compared with frequently burnt rainforest–savanna mosaics in the north Kimberley, Australia

Abstract ContextPopulations of native mammals are declining at an alarming rate in many parts of tropical northern Australia. Fire regimes are considered a contributing factor, but this hypothesis is difficult to test because of the ubiquity of fire. AimsThis preliminary study investigated relative abundance and richness of small mammals on a gradient of fire regimes in the Uunguu Indigenous Protected Area (north Kimberley, Australia). MethodsSpecies were sampled using 40 unbaited camera traps, positioned for a year on 20 transects crossing the rainforest–savanna boundary at locations with comparable environment and geology but varying fire history. The relative importance of the factors ‘fire frequency’, ‘late dry season fire frequency’, ‘time since burnt’ and ‘vegetation type’ as predictors of the number of small mammal species and detections was tested using Spatial Generalised Linear Mixed Models to account for spatial autocorrelation. Key resultsNine species of small mammals were observed. Mammals were more abundant and diverse in locations with low overall fire frequency, which was a better predictor than late dry season fire frequency or time since burnt. The model including fire frequency and vegetation explained the highest proportion of total variation in mammal diversity (R2=42.0%), with most of this variation explained by fire frequency alone (R2=40.5%). The best model for number of detections (R2=20.9%) included both factors. ConclusionsIn the north Kimberley, small mammals are likely to be more abundant and diverse in areas with low fire frequency. ImplicationsThis natural experiment supports the theory that frequent fires are contributing to the decline of small mammals observed across northern Australia.

Response of bat activity to land cover and land use in savannas is scale-, season-, and guild-specific

Tropical savannas are biomes of global importance under severe pressure from anthropogenic change, including land-cover and land-use change. Bats, the second-most diverse group of mammals, are critical to ecosystem functioning, but vulnerable to such anthropogenic stresses. There is little information on how savanna bats respond to land cover and land use, especially in Africa, limiting our ability to develop conservation strategies for bats and maintain the ecosystem functions and services they provide in this biome. Using acoustic monitoring, we measured guild-specific (aerial, edge, and clutter forager) responses of bat activity to both fine-scale vegetation structure and landscape-scale land-cover composition and configuration across the wet and dry seasons in a southern African savanna undergoing rapid land-cover and land-use change. Responses were guild- and season-specific but generally stronger in the dry season. Aerial and clutter bats responded most strongly to landscape metrics in the dry season (positive responses to savanna fragmentation and water cover, respectively) but fine-scale metrics in the wet season (positive responses to water cover and grass cover, respectively). Edge bats responded most strongly (negatively) to the distance to water in the dry season and fine-scale shrub cover in the wet season. Our results show it is possible to maintain high levels of bat activity in savanna mosaics comprised of different land covers and land uses. Bats, and the ecosystem services they provide, can be conserved in these changing landscapes, but strategies to do so must consider foraging guild, spatial scale, and seasonal variation in bat activity.

Density and distribution of western chimpanzees around a bauxite deposit in the Boé Sector, Guinea‐Bissau

The Boé sector in southeast Guinea-Bissau harbors a population of western chimpanzees (Pan troglodytes verus) that inhabits a mosaic of forest and savanna. The Boé sector contains a substantial bauxite deposit in a region called Ronde Hill, and there are plans for the construction of a mine, which may endanger the chimpanzee population. In 1-week survey in May 2013, we used the standing crop nest counts method to obtain the number of chimpanzee nests and from that estimate the density and abundance of chimpanzees. We carried out five 1-km line transects that covered the bauxite deposit and surrounding valleys. We used density surface modeling to analyze habitat preferences, then predicted chimpanzee nest density and distribution based on environmental variables. We found the projected location of the mine partially coincides with an area of high predicted abundances of chimpanzee nests and is surrounded by highly suitable areas for chimpanzees (northeast and southwest). We conclude the mine could have significant direct and indirect effects on this population of chimpanzees whose impacts must be carefully considered and properly mitigated if the mine is built.

Food abundance and weather influence habitat-specific ranging patterns in forest- and savanna mosaic-dwelling red-tailed monkeys (Cercopithecus ascanius).

Primates that live in predominantly forested habitats and open, savanna mosaics should exhibit behavioral responses to differing food distributions and weather. We compared ecological constraints on red-tailed monkey ranging behavior in forest and savanna mosaic environments. Intraspecific variation in adaptations to these conditions may reflect similar pressures faced by hominins during the Plio-Pleistocene. We followed six groups in moist evergreen forest at Ngogo (Uganda) and one group in a savanna-woodland mosaic at the Issa Valley (Tanzania). We used spatial analyses to compare home range sizes and daily travel distances (DTD) between sites. We used measures of vegetation density and phenology to interpolate spatially explicit indices of food (fruit, flower, and leaves) abundance. We modeled DTD and range use against food abundance. We modeled DTD and at Issa hourly travel distances (HTD), against temperature and rainfall. Compared to Issa, monkeys at Ngogo exhibited significantly smaller home ranges and less variation in DTD. DTD related negatively to fruit abundance, which had a stronger effect at Issa. DTD and HTD related negatively to temperature but not rainfall. This effect did not differ significantly between sites. Home range use did not relate to food abundance at either site. Our results indicate food availability and thermoregulatory constraints influence red-tailed monkey ranging patterns. Intraspecific variation in home range sizes and DTD likely reflects different food distributions in closed and open habitats. We compare our results with hypotheses of evolved hominin behavior associated with the Plio-Pleistocene shift from similar closed to open environments.

How complementary are large frugivores for tree seedling recruitment? A case study in the Congo Basin

AbstractLarge frugivores provide critical seed dispersal services for many plant species and their extirpation from forested ecosystems can cause compositional shifts in regenerating plant cohorts. Yet, we still poorly understand whether large seed-dispersers have complementary or redundant roles for forest regeneration. Here, to assess the functional complementarity of large-bodied frugivores in forest regeneration, we quantified the effects of varying abundance of hornbills, primates and the forest elephant on the density, species richness and the mean weighted seed length of animal-dispersed tree species among seedlings in five sites in a forest–savanna mosaic in D. R. Congo, while accounting for percentage forest cover and the local presence of fruiting trees. We found that the abundance of primates was positively associated with species richness of seedlings, while percentage forest cover was negatively associated (R2 = 0.19). The abundance of hornbills, the presence of elephants and percentage forest cover were positively associated with mean seed length of the regenerating cohort (R2 = 0.13). Spatially explicit analysis indicated that some additional processes have an important influence on these response indices. Primates would seem to have a preponderant role for maintaining relatively high species richness, while hornbills and elephant would seem to be predominantly responsible for the recruitment of large-seeded trees. Our results could indicate that these taxa of frugivores play complementary functional roles for forest regeneration. This suggests that the extirpation of one or more of these dispersers would likely not be functionally compensated for by the remaining taxa, hence possibly cascading into compositional shifts.

Habitat differentiation among three Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) populations.

Ecological niche models (ENMs) are often used to predict species distribution patterns from datasets that describe abiotic and biotic factors at coarse spatial scales. Ground‐truthing ENMs provide important information about how these factors relate to species‐specific requirements at a scale that is biologically relevant for the species. Chimpanzees are territorial and have a predominantly frugivorous diet. The spatial and temporal variation in fruit availability for different chimpanzee populations is thus crucial, but rarely depicted in ENMs. The genetic and geographic distinction within Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) populations represents a unique opportunity to understand fine scale species‐relevant ecological variation in relation to ENMs. In Cameroon, P. t. ellioti is composed of two genetically distinct populations that occupy different niches: rainforests in western Cameroon and forest–woodland–savanna mosaic (ecotone) in central Cameroon. We investigated habitat variation at three representative sites using chimpanzee‐relevant environmental variables, including fruit availability, to assess how these variables distinguish these niches from one another. Contrary to the assumption of most ENM studies that intact forest is essential for the survival of chimpanzees, we hypothesized that the ecotone and human‐modified habitats in Cameroon have sufficient resources to sustain large chimpanzee populations. Rainfall, and the diversity, density, and size of trees were higher at the rainforest. The ecotone had a higher density of terrestrial herbs and lianas. Fruit availability was higher at Ganga (ecotone) than at Bekob and Njuma. Seasonal variation in fruit availability was highest at Ganga, and periods of fruit scarcity were longer than at the rainforest sites. Introduced and secondary forest species linked with anthropogenic modification were common at Bekob, which reduced seasonality in fruit availability. Our findings highlight the value of incorporating fine scale species‐relevant ecological data to create more realistic models, which have implications for local conservation planning efforts.

Cattle affect regeneration of the palm species Attalea princeps in a Bolivian forest–savanna mosaic

AbstractAttalea princeps is an important palm species that shapes the forest–savanna mosaic in Beni, Bolivia, as it dominates the two principal forest landscape elements (forest islands and gallery forest), and provides a vital microhabitat, food, and nesting source for numerous plant and animal species. The forest–savanna mosaic is used for extensive grazing, and the palm population is declining on the forest islands due to a low regeneration rate, which threatens the maintenance of this landscape. We therefore examined the (a)biotic factors that influence the population structure of Attalea in the centers and edges of forest islands and gallery forests. Ninety‐one 0.1‐ha plots were established, and 500 palm adults and 3,700 juveniles were measured for their size, health condition, and fire damage. For each plot, habitat characteristics, such as landscape position, grazing pressure, and soil conditions, were measured. Attalea population density was significantly lower on the forest islands than in the gallery forests, especially in the juvenile life stage. A structural equation model showed that juvenile density is positively related to the health condition of juveniles and amount of fruits present, where the amount of fruits is positively affected by the condition of adults. Juvenile density is negatively influenced by grazing, affecting the health condition of the juvenile, as well as organic matter and phosphate availability in the soil. Therefore, it is recommended to decrease the grazing pressure by decreasing livestock densities, fencing off vulnerable forest islands, or by rotating cattle.Abstract in Spanish is available with online material.

Sixty years of community change in the prairie-savanna-forest mosaic of Wisconsin.

Biodiversity loss is a global concern, and maintaining habitat complexity in naturally patchy landscapes can help retain regional diversity. A mosaic of prairie, savanna, and forest historically occurred across central North America but currently is highly fragmented due to human land conversion. It is unclear how each habitat type now contributes to regional diversity. Using legacy data, we resurveyed savanna plant communities originally surveyed in the 1950s to compare change in savannas to that in remnant forests and prairies. Savanna community structure and composition changed substantially over the past 60 years. Tree canopy density nearly doubled and many prairie and savanna specialist species were replaced by forest and non‐native species. All three habitats gained and lost many species since the 1950s, resulting in large changes in community composition from local colonizations and extinctions. Across all three habitats, regional species extinctions matched that of regional colonization resulting in no net change in regional species richness. Synthesis—Despite considerable species turnover within savannas, many species remain within the broader prairie–savanna–forest mosaic. Both regional extinctions and colonizations were high over the past 60 years, and maintaining the presence of all three community types—prairie, savanna and forest—on the landscape is critical to maintaining regional biodiversity.

Catálogo de la flora de los Parques Nacionales Naturales de Colombia: Parque Nacional Natural El Tuparro

The Tuparro National Natural Park is the only conservation area of national character that is located in the high plains of the Colombian Orinoquia. Its vegetation corresponds to a mosaic of savannas with patches of swamp forests and matas de monte in non-flooded terrain. Since its establishment as a conservation area in 1970, multiple collections were deposited mainly in the Federico Medem Bogota (FMB), Nacional Colombiano (COL) and Missouri Botanical Garden (MO) herbaria. The review of these collections shows a list of 768 species of vascular plants grouped in 114 families and 448 genera. One-hundred and sixteen species with some threat category, 5 with some local use, and 14 as Values Subject of Conservation are documented. Endemic species to the Park were not found, probably due to the fact that the ecosystems of the Park are also found in other regions of the Orinoco basin in Colombia and Venezuela. 71% of the listed species are associated with forest vegetation, and 25% to savannas. It is estimated that the floristic inventory of the Park is quite complete in terms of collections but that a comprehensive review of collections by specialists is still necessary and could increase the number of species up to about 7%.

Steal the light: shade vs fire adapted vegetation in forest-savanna mosaics.

Shade cast by trees, which suppresses grass growth, and fire fuelled by grass biomass, which prevents tree sapling establishment, are mutually exclusive and self-reinforcing drivers of biome distribution in savanna-forest mosaics. We investigated how shade depth, represented by canopy leaf area index (LAI), is generated by adult trees across savanna-forest boundaries and how a shade gradient filters tree functioning, and grass composition and biomass. Forest trees exerted greater shading through increased stem density and greater light interception per unit biomass. A critical transition at LAI c. 1.5 was linked to tree shifts from savanna to forest species, functional shifts from fire-tolerant to light-competitive species, and grass composition shifts from C4 to C3 pathways. A second transition to grass fuel loads too low to support fires, occurred at a lower canopy density (LAI>0.5), accompanied by shifts in C4 subtype dominance. This pattern suggests that shade suppression of grass biomass is an essential first step for the maintenance of alternative stable states.

Human impact on African forests

Paleoecology About 2600 years ago, continuous forest in western central Africa was replaced by a mosaic of forest and savanna. It has been unclear, however, whether this was caused by climate change or expansion of the contemporary human population. Using a sedimentary record of vegetation and hydrological history from Cameroon, Garcin et al. confirm the key role of humans in this transition. Although the pollen record indicates an abrupt fragmentation of the forest, there is no signature of an accompanying hydrological change. Nor did the hydrology alter 500 years later when the landscape reverted once more to forest, indicating a negligible role for climate. Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1715336115 (2018).

Nocturnal behavior by a diurnal ape, the West African chimpanzee (Pan troglodytes verus), in a savanna environment at Fongoli, Senegal.

I report on the nocturnal behavior of Fongoli chimpanzees in a savanna mosaic during different seasons and lunar phases and test the hypothesis that hot daytime temperatures influence activity at night. I predicted that apes would be more active at night during periods of greater lunar illuminosity given diurnal primates' lack of visual specializations for low-light conditions and in dry season months when water scarcity exacerbated heat stress. I observed chimpanzees for 403 hrs on 40 nights between 2007 and 2013 and categorized their activity as social, movement, or vocalization. I scored their activity as occurring after moonrise or before moonset and considered the influence of moon phase (fuller versus darker phases) as well as season on chimpanzee nocturnal behavior in the analyses. Results indicate that apes were more active after moonrise or before moonset during fuller moon phases in the dry season but not the wet season. Most night-time activity involved movement (travel or forage), followed by social behavior, and long-distance vocal communication. Animals in highly seasonal habitats often exhibit thermoregulatory adaptations but, like other primates, chimpanzees lack physiological mechanisms to combat thermal stress. This study provides evidence that they may exhibit behaviors that allow them to avoid high temperatures in a savanna environment, such as feeding and socializing at night during the hottest time of year and in the brightest moon phases. The results support theories invoking thermal stress as a selective pressure for hominins in open environments where heat would constrain temporal foraging niches, and suggest an adaptability of sleeping patterns in response to external factors.

Spatial variation of bat diversity between three floodplain-savanna ecosystems of the Colombian Llanos

The ecology of bat assemblages in savanna ecosystems is poorly known. Studies on this subject are scarce in the Colombian Orinoquia; some authors have argued that this region shows a low diversity of bat species relative to other natural regions of Colombia, which contrasts with reports for other Neotropical savannas. In order to broaden the knowledge about bat assemblages in savanna ecosystems in Colombia, we evaluated the alpha (local) and beta (species turnover) diversities in three savanna ecosystems located in Colombian alluvial flood plains of Orinoco Llanos , as compared to other natural regions of Colombia. We sampled bat assemblages across three alluvial floodplain savannas: E1) Mosaic of floodplain savannas and floodplain forests covering less than 20 % of the original area. E2) Dense high forest growing on the flood plains of Whitewater Andean rivers. E3) Aeolian savannas. Mist nets were used in the understory in all cases. We evaluated the representativeness of samples using the Jackknife 1 estimator. The species richness found was compared with the one reported in representative inventories of other natural regions of Colombia. Differences in alpha diversity between the three ecosystems studied were explored by comparing rank-abundance curves and three true-diversity values (q0, q1 and q2). Finally, we evaluated the species turnover across ecosystems using the Jaccard similarity index. A total of 50 bat species were recorded at the regional level, and between 32 and 39 species in each of the ecosystems, representing a greater or similar richness vs other natural regions of Colombia. Sampling representativeness was higher than 80 %. Although no differences were observed in terms of species richness (q0) between localities, differences were evident in the structure of assemblages (q1, q2). Finally, the species turnover between localities was high, with similarity values between 57 % and 64 %. The species richness recorded in the assemblages studied here is similar to that reported for bat assemblages in other natural regions of Colombia, where a higher diversity has been presumed. The differences observed in the structure of abundances of the assemblages studied here may be associated with ecosystem heterogeneity in the Llanos region, characterized by different types of vegetation structure in the various types of forest. In addition, there may be a negative effect of the degree of transformation of natural ecosystems on bat richness and diversity. On the other hand, the high degree of bat species turnover may stem from differences in the composition and structure of riparian forests coupled with the strong seasonality of precipitation in the region, as reported for other Neotropical savannas.

Soil or fire: what causes treeless sedgelands in Tasmanian wet forests?

Ecologists fiercely debate the role of soil conditions and fire regimes in controlling forest – savanna boundaries. A prominent component of this debate centres on the plausibility and existence of fire-mediated alternative stable state dynamics (FMASS), a model first proposed by the Tasmanian ecologist WD Jackson in 1968. The FMASS model asserts that increased or decreased landscape fire activity, often due to human intervention, can overwhelm physical environmental (e.g. topography and edaphic factors) controls of forest and savanna mosaics, thereby creating landscape dynamism. Many FMASS models include fire-vegetation-soil interactions (FVS), in which changes in fire frequency can change soil fertility and hence tree growth. This interaction, in turn, affects the capacity offorests to recover from disturbance and long unburnt savanna to convert to forest. We evaluate support for the FMASS-FVS model in the context of the dynamics of the Tasmanian forests that have recently been drawn into wider, global debates surrounding the co-occurrence of tree and treeless vegetation states. We develop a simple spatial simulation model to illuminate the difficulties in analysing landscape pattern to draw inferences about the existence of FMASS-FVS. Our review of the Tasmanian evidence shows that FMASS-FVS cannot unambiguously explain all tracts of sedgelands in Tasmanian wet forests, and hence Tasmania should not be used as an exemplar of these theories globally. Our simulations highlight that soil sampling that targets forest boundaries risks erroneously concluding that the distribution of forest and savanna boundaries is decoupled from edaphic factors. We describe a structured methodological pathway that can identify the role of FMASS-FVS in Tasmanian forest dynamics, and elsewhere in the world. This approach use cross-scale temporal and spatial analyses, and targeted experimental tests, to illuminate the interplay of fire, vegetation and edaphic factors in controlling tree establishment and growth and forest boundary dynamics.

Lack of floristic identity in campos rupestres—A hyperdiverse mosaic of rocky montane savannas in South America

The rocky montane savannas of South America, known as campos rupestres in Brazil, where they largely occur, represent a hyperdiverse habitat housing c.15% of the Brazilian vascular flora in less than 1% of the Brazilian territory. Amongst other factors, the remarkable plant diversity in campos rupestres has been attributed to its occurrence as many isolated patches and to floristic influences from surrounding habitats, including lowland woody savannas (cerrado), Atlantic rain forests, seasonally dry woodlands and Amazonian rain forests. However, no study has assessed the degree to which the putative floristic influence from surrounding habitats drives compositional variation in campos rupestres. Here, we used a dataset on the composition of South American woody plant communities (4,637 community surveys, with 115 representing campos rupestres), combined with environmental data, with the aim of characterising and explaining compositional variation of the campos rupestres woody flora. Our results showed that all campos rupestres, including the sites occurring in Amazonian ironstone formations, are more similar to cerrado woody savannas than to any other South American vegetation formations covered in our dataset. Also, multiple campo rupestre floristic groups may be recognized based on distinct species composition and environmental conditions, primarily related to substrate and climate. We stress the importance of considering this floristic heterogeneity in conservation, management and research planning.