White-sand Habitats Research Articles

Phylogenomics of the Palm Tribe Lepidocaryeae (Calamoideae: Arecaceae) and Description of a New Species ofMauritiella

Abstract—The palm tribe Lepidocaryeae (Arecaceae) comprises seven genera and 51 currently accepted species that are distributed in lowland tropical forests and savannas across Africa and the Americas. Subtribal relationships within Lepidocaryeae have been a persistent challenge, limiting our understanding of its systematics, morphology, and biogeography. Several aspects make the tribe an ideal system to study plant evolution and diversity: it is well-represented in the fossil record as a prolific pollen producer, its continental diversity contradicts common biodiversity patterns of lower species richness in Africa in comparison to South America, and it contains one of the most abundant Amazonian tree species,Mauritia flexuosa. Here, we investigated the systematics of the tribe by sampling 122 individuals representing 42 species (82% of the tribe), using target sequence capture. We recovered nearly 10,000 single nucleotide polymorphisms from nuclear and plastid DNA across 146 target sequences to separately infer a phylogenomic tree. Our results strongly support inter-generic and inter-specific relationships, where a majority of nodes were resolved with over 90% bootstrap support. We also identify strong phylogenetic support for the recognition of a new species from central and south Amazonia,Mauritiella disticha. The distichous phyllotaxy is diagnostic of the species within the genus. Rare and currently only known from the middle-lower Madeira River basin in the state of Amazonas, Brazil,M. distichais restricted to open vegetation and forest edges growing in white sand habitats with saturated or well-drained soils. Our preliminary red list assessment suggests its threatened status to be vulnerable (VU). We use our phylogenomic inference to define and contextualize systematic relationships in the tribe, and present a formal species description.

The Amazonian Croton mollis (Euphorbiaceae): morphology and leaf anatomy help to understand its preference for the extreme igapó habitat

Identifying traits contributing to the success of organisms living in harsh environments has always been of great interest in evolutionary ecology. Here we focused on morphological features that could be advantageous for the survival of Croton mollis, a slender shrub occurring in the extreme white-sand habitats of the Amazonian igapos (black/clear-water rivers). We examined macro-morphological characters, as well as leaf micro-morphology using light microscopy and scanning electron microscopy. We also estimated areas of habitat suitability for C. mollis based on climatic, soil, and elevation variables using species distribution modelling (SDM) and available herbarium collections. Our results show that C. mollis presents morphological attributes similar to those of rheophytes, which may allow the species to overcome drastic seasonal changes in water level. We report the presence of five secretory structures (extrafloral nectaries, colleters, idioblasts, glandular trichomes, and laticifers) in the leaves. The size and position of the secretory idioblasts support the hypothesis of the existence of a transitional storage for secondary metabolites from idioblasts to secretory trichomes. Besides glandular trichomes, we also found stellate trichomes and trichome-like emergences in leaves. We hypothesize that these emergences could have an important role in the species’ survival due to their capacity of absorbing atmospheric moisture. Finally, the SDM supported the known habitat preferences of C. mollis and estimated a relatively wider geographic range than the currently known distribution based on herbarium records, suggesting that collecting efforts in the Amazonian region need to be increased in the future.

Floristics, phytosociology and biogeography of capitinga vegetation in a white sand habitat in the Chapada Diamantina Mountains, Brazil

Abstract Capitinga is poorly studied vegetation growing on small, scattered islands of fine, white sand surrounded by the latosol forests on the eastern flank of the Chapada Diamantina Mountains in northeastern Brazil. Our study characterized capitinga vegetation, its environmental features, and compared its flora with the vegetation mosaic within the Espinhaço and Chapada Diamantina ranges. Floristic data was collected from 1999-2006, and phytosociological surveys were undertaken in 2004-2005 and 2016-2017 within fifteen 50 x 2 m plots (100 m2 each, 1500 m2 in total). Multivariate grouping and ordination analysis were used to examine the floristic affinities of capitinga vegetation. Sixty different species from 36 families were recorded overall, while a total of 4945 individuals distributed among 25 families and 33 species were recorded in the plots. The richest families were Fabaceae (7) and Apocynaceae (5), while the most abundant families were Arecaceae (61.5% of all individuals) and Velloziaceae (18.4%), represented by Syagrus harleyi and Vellozia dasypus respectively. Capitinga represents a distinct habitat conditioned by edaphic features, and its flora is unlike other vegetations in the Espinhaço or Chapada Diamantina ranges, with several locally endemic species.

Sister species, different histories: comparative phylogeography of two bird species associated with Amazonian open vegetation

AbstractAlthough the expansion of open vegetation within Amazonia was the basis for the Forest Refugia hypothesis, studies of Amazonian biota diversification have focussed mostly on forest taxa. Here we compare the phylogeographic patterns and population history of two sister species associated with Amazonian open-vegetation patches, Elaenia cristata and Elaenia ruficeps (Aves: Tyrannidae). We sampled individuals across Amazonia for both species, and in the central Brazilian savannas (Cerrado) for E. cristata. We sequenced one mitochondrial (ND2) and two nuclear (BFib7 and ACO) markers. We tested for population structure, estimated migration rates and elucidated the historical demography of each species. The Amazon River is the strongest barrier for E. ruficeps and the Branco River is a secondary barrier. For the more broadly distributed E. cristata, there was no discernible population structure. Both species attained their current genetic diversity recently and E. cristata has undergone demographic expansion since the Last Glacial Maximum, The results suggest distinct effects of recent landscape change on population history for the two species. E. ruficeps, which only occurs in Amazonian white sand habitats, has been more isolated in open-vegetation patches than E. cristata, which occupies Amazonian savannas, and extends into the Central Brazilian Cerrado.

First record of the gray-legged tinamou, Crypturellus duidae, and other poor-soil specialist birds from peatlands in the Putumayo River basin, Loreto, Peru

ABSTRACT Crypturellus duidae (Tinamidae) is a poor-soil specialist with isolated populations in Amazonia, and is considered restricted to white-sand forest habitats. We report the first record of C. duidae in a peatland forest in northern Peru, in the Putumayo River basin. Our record extends the known distribution of C. duidae between two disjoint areas of occurrence in Peru and Colombia, and shows its presence in peatland forest, another forest type on nutrient-poor soils. Additionally, we report the presence of other poor-soil specialist bird species that were previously registered in peatlands. Together with the new record of C. duidae, these bird records provide evidence of the diversity of poor-soil specialists in peatland forests.

Drosera stipularis, a new species for the D. petiolaris complex from Cape York Peninsula, Queensland

Across tropical northern Australia 14 Drosera species are recognised within the D. petiolaris complex. The complex is placed in section Lasiocephala; a group of perennial sundews mostly characterised by an indumentum of white hairs upon the petiole. Here we describe a new species for the complex, D. stipularis
 Baleeiro, R.W.Jobson & R.L.Barrett, which is known only from white-sand habitats on Cape York Peninsula, Queensland. The new species is allied to D. petiolaris R.Br. ex DC. and D. lanata K.Kondo.

Longistriata flava (Boletaceae, Basidiomycota) - a new monotypic sequestrate genus and species from Brazilian Atlantic Forest.

A new monotypic sequestrate genus, Longistriata is described based on collections from the Neotropical forest of Atlantic forest in Paraíba, Northeast Brazil – an area known for its high degree of endemism. The striking features of this new fungus are the hypogeous habit, the vivid yellow peridium in mature basidiomes, broadly ellipsoid basidiospores with a distinct wall that is ornamented with longitudinal striations and lageniform cystidia with rounded apices. Phylogenetic analysis, based on LSU and tef-1α regions, showed that the type species, Longistriataflava, is phylogenetically sister to the monotypic sequestrate African genus Mackintoshia in Boletaceae. Together these two species formed the earliest diverging lineage in the subfamily Zangioideae. Longistriataflava is found in nutrient-poor white sand habitats where plants in the genera Coccoloba (Polygonaceae) and Guapira (Nyctaginaceae) are the only potential ectomycorrhizal host symbionts.

Cactaceae of the Serra Geral, Monte Azul, Minas Gerais (Brazil) revisited

A checklist of Cactaceae found during the ascent of the Serra Geral, east of Monte Azul, Minas Gerais (Brazil) is presented, listing 17 species, the second most cactus-diverse area known in Eastern Brazil. Slightly below the crest of the serra, in Campo Rupestre, a white sand habitat for Cipocereus pusilliflorus is illustrated together with other cacti observed in the area and its conservation status is discussed.

Flesh flies (Diptera: Sarcophagidae) from a white-sand habitat in the Brazilian Amazon, with the description of four new species.

The white-sand enclaves in the Amazon Basin are small areas scattered through the tropical forest, with sandy and nutrient-poor soils and an unusual vegetation type. The insect fauna of this ecosystem is poorly known, especially in the eastern Amazon. The flesh fly fauna of an area of open herbaceous white-sand vegetation known as "Campo Redondo" in the municipality of Cametá, state of Pará, was surveyed, resulting in the discovery of 43 species in 11 genera representing the subfamilies Sarcophaginae and Miltogramminae. Four new species are described: Dexosarcophaga (Dexosarcophaga) campina sp. nov., Helicobia cametaensis sp. nov., Helicobia domquixote sp. nov., and Metopia fofo sp. nov. Lepidodexia (Lepidodexia) grisea Lopes and Lepidodexia (Notochaeta) setifrons (Lopes) are newly recorded from Brazil. Dexosarcophaga (Bezzisca) ampullula (Engel), D. (Dexosarcophaga) transita Townsend and Titanogrypa (Cucullomyia) larvicida (Lopes) are newly recorded from the Brazilian Amazon.

Neuroanatomical Changes Related to a Changing Environment in Lesser Earless Lizards

Abstract How do changes in the environment affect the brain? More specifically, how do different physical environments shape areas of the brain that facilitate the contextual perception of animals' surroundings? We evaluated the relationship between rapid habitat change and the volume of the medial, lateral, and dorsal cortices, in two populations of wild male and female Lesser Earless Lizards (Holbrookia maculata). These populations inhabit neighboring, but physically distinct, environments in southern New Mexico: White Sands and dark soil habitats. The White Sands habitat is a geologically recent environment that formed over the last 2,000–7,000 yr. There is a stark physical contrast between White Sands and the surrounding typical Chihuahuan desert habitat that is characterized by dark soil, denser vegetation, and higher competitor and predator species abundances. We observed differences in the volumes of the medial cortex, an important neuroanatomical structure for navigation, but not in those of the d...

Colonization of a novel depauperate habitat leads to trophic niche shifts in three desert lizard species

In a novel, depauperate ecosystem, colonizing species may experience changes in their trophic niche as a result of a new resource base and fewer competitors and predators. To examine trophic niche shifts of recent colonists, we focused on three ecologically and phylogenetically divergent lizard species that inhabit both the geologically distinctive depauperate habitat of White Sands and the surrounding Chihuahuan ‘dark soil’ desert in New Mexico. In White Sands the three species comprise the entire lizard community, whereas in the dark soils habitat, they constitute less than half of the lizard community abundance. As a result, we hypothesized that the three focal species would collectively represent a greater variety of trophic positions in the White Sands habitat than in the dark soils habitat. We hypothesized that the extent of shifts in each species’ trophic position would parallel diet and ecomorphology differences between habitats. To test these hypotheses, we combined analysis of lizard stomach contents with carbon and nitrogen stable isotopes in the context of previously published ecomorphology measurements. Stable isotope data indicated that as predicted, species were more different from one another in White Sands than in dark soils, suggesting community‐wide ecological release. Overall, all species were lower on the White Sands food chain; however, only one species decreased trophic level significantly, one increased trophic level variance, and one did not change significantly. Furthermore, stomach content data paralleled both stable isotope and ecomorphological data, showing different degrees of dietary overlap between habitats, depending on the species. That species’ differences in trophic ecology also correspond with ecomorphological differences suggests that these factors are either causally linked or collectively responding to similar ecological pressures, such as competition. By examining diet, trophic position, and ecomorphology of three colonist species, we demonstrate both species‐specific and community‐wide trophic differences in adjacent, but distinct habitats.

Evidence for ecological release over a fine spatial scale in a lizard from the White Sands formation

When a population experiences relaxation of selective pressures due to reduced predation or competition, it may undergo ecological release. Ecological release often manifests as increased niche breadth and trait variation, as individuals have the opportunity to exploit a wider variety of resources. At the recently‐colonized White Sands dune formation in New Mexico, lizards from white sand habitat have fewer predators and competitors than their dark soil counterparts, and show evidence of ecological release compared to dark soil lizards. To determine whether the dynamics of ecological release also play out over an even finer habitat gradient, we studied southwestern fence lizards in the center of the White Sands dune formation and the narrow ecotone between White Sands and the surrounding dark soil habitats. We predicted that lizards from the central dunes would exhibit ecological release in terms of broadened resource use compared to lizards from the ecotone. We first conducted avian surveys in both the central dunes and ecotone habitats to measure abundance, richness and diversity of avian species that could act as lizard predators. Next, we measured microhabitat‐scale resource use by comparing perch selection of lizards in both habitats. Finally, we measured landscape‐scale resource use by quantifying home range sizes and daily distances traveled by lizards in both habitats. We found that central dunes lizards used a greater diversity of perch types, and had greater variation in both home range size and daily distances traveled, than ecotone lizards. There were fewer predatory bird species in the central dunes than on the ecotone, and there was a tendency for fewer predation events in the central dunes than on the ecotone. Our results demonstrate that ecological release is detectable over a fine habitat gradient, such as between the center of a recently‐colonized habitat and its ecotone with the surrounding ecosystem.

Distance and habitat drive fine scale stingless bee (Hymenoptera: Apidae) community turnover across naturally heterogeneous forests in the western Amazon

High tree species richness in the western Amazon has been attributed to heterogeneous soils, which harbor edaphic specialist trees. While rapid transitions in tree communities are well documented across these variable soils few studies have investigated the role of habitat heterogeneity in structuring animal communities. Stingless bees are taxonomically diverse and important natural pollinators in Neotropical forests. However, little is known about their community structuring at local scales in naturally heterogeneous environments. We systematically sampled stingless bee communities found across three paired sites that included adjacent patches of white-sand and non-white-sand forest in the lowland Amazonian region of Loreto, Peru. We sought to understand: (1) How stingless bee species richness and abundance differs among white-sand and non-white-sand habitats and (2) The relative influence of fine scale geographic distance and habitat type in structuring stingless bee communities. We found that species richness did not differ between habitats and that species abundances were highest in white-sand habitats. Community analyses for sampling sites pooled across all months demonstrated that location and soil type played a significant role in structuring bee communities and that community turnover may be more strongly influenced by distance in white-sand habitats than non-white sand habitats. Our results suggest that distance and habitat play an important role in driving stingless bee community turnover at fine scales and that the interaction between habitat and geographic distance may promote higher stingless bee community turnover in white-sand habitats than non-white sand habitats.

Ecological release and directional change in White Sands lizard trophic ecomorphology

A species’ trophic ecomorphology can change drastically following the colonization of a new environment. Resource shifts may result in dietary change of colonists and therefore, the evolution of ecomorphological adaptations such as changes in bite force, head, and body size. To understand the drivers and dynamics of ecomorphological change after colonization we studied prey availability, diet, performance, and morphology in three lizard species (Aspidoscelis inornata, Holbrookia maculata, and Sceloporus cowlesi) in the ecologically distinct environment of White Sands, New Mexico. White Sands, which formed within the last 6,000 years, was most likely colonized by nearby “dark soils” populations. Therefore, for each species we compared White Sands individuals to conspecific inhabiting the surrounding Chihuahuan Desert habitat. The White Sands habitat had higher prey morphospecies richness, increased breadth of prey orders, and a higher percentage of hard-bodied prey than the dark soils habitat. Differences in prey availability in White Sands and dark soils habitats were reflected in lizard diets. Specifically, morphospecies richness and percentage of hard bodied prey were higher in the diet of White Sands lizards compared to dark soils lizards. These similarities in resource use across the three species in two habitats indicated parallel responses to a shared environment. Although some dietary shifts in the three species were predictable and reflected prey availability, differences in performance and morphology traits indicated different ecological responses in each species. In general, average prey hardness was higher in the two White Sands species that had stronger absolute bite force and larger absolute head size. While White Sands lizards generally also included a larger proportion of hard prey in their diets, had higher absolute bite-force, head size, and body size than dark soils lizards, the magnitude of these differences varied across species.

Two new African species of <I>Salacia</I> (<I>Salacioideae, Celastraceae</I>)

Two new African species of Salacia (Salacioideae, Celastraceae) are described. Salacia arenicola is a scandent shrub endemic to a restricted white sand habitat in coastal Republic of Congo. It is assessed as IUCN 2012 category Vulnerable (VU). Salacia nigra is an erect shrub or small tree with dark purple flowers and large leaves found in the wet coastal forests of Cameroon and Nigeria and is also assessed as Vulnerable. A key to nonlianescent tropical African Salacias is given.

Beyond black and white: divergent behaviour and performance in three rapidly evolving lizard species at White Sands

Determining which traits enable organisms to colonize and persist in new environments is key to understanding adaptation and ecological speciation. New environments can present novel selective pressures on colonists' morphology, behaviour, and performance, collectively referred to as ecomorphology. To investigate ecomorphological change during adaptation and incipient ecological speciation, we measured differences in morphology (body shape and size), behaviour (startle response), and performance (sprint speed) in three New Mexican lizard species: Holbrookia maculata, Sceloporus undulatus, and Aspidoscelis inornata. Each species is represented by dark morphs, cryptic on the brown adobe soils of the Chihuahuan Desert, and white morphs, cryptic on the gypsum substrate of White Sands. For each species, we then determined the effects of morphology and startle response on sprint speed on matched and mismatched substrate. For two of the three species, white morphs had larger body size and longer limbs. However, we found no statistical evidence that these morphological differences affected sprint speed. Colour morphs also exhibited different escape responses on the two substrates: in all species, dark morphs were less likely to immediately sprint from a simulated predator on white sand. As a result, escape response had a significant effect on sprint speed for two of the three species. Not surprisingly, all lizards sprinted faster on dark soil, which was probably due to the lizards' more immediate escape response and the higher compaction of dark soil. The relationship between escape response and sprint performance across the dark soil and white sand habitats suggests that behavioural differences may be an important component of adaptation and speciation in new environments. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 169–182.

<p><strong><em>Croton campinarensis</em></strong><strong> (Euphorbiaceae), a new species from eastern Amazonian Brazil</strong></p>

A new species of Euphorbiaceae from eastern Amazonian Brazil, Croton campinarensis, is described and illustrated here. It belongs to Croton section Geiseleria and shares some features with C. strobiliformis, another Amazonian species of white sand habitats.

A New Amazonian Section of Protium (Burseraceae) including both Edaphic Specialist and Generalist Taxa. Studies in Neotropical Burseraceae XVI.

Abstract Protium section Papilloprotium and Protium alvarezianum are described and a key to the four species of the section provided. The section is distinguished principally by its papillate abaxial leaflet surface, and the petals saccate at base and villous adaxially. The rather widespread edaphic generalist P. ferrugineum shares a common ancestor with two small clades, one containing two white-sand specialists (P. reticulatum and P. alvarezianum) that appear to have diverged from a common ancestor allopatrically via fragmentation of white-sand habitats, and the other exhibiting degrees of edaphic specialization among variants of P. subserratum. This scenario highlights the role of edaphic heterogeneity as a driver in the diversification of the Amazon flora.

Colonization of novel White Sands habitat is associated with changes in lizard anti-predator behaviour

Colonization of novel habitats is often associated with differences in ecological community composition. For small diurnal animals, differences in predator diversity and abundance can lead to behavioural shifts in the novel habitat. The eastern fence lizard Sceloporus undulatus (Bosc and Daudin, 1801) recently colonized the gypsum dunes of White Sands, a predator-poor community relative to the predator-rich community of the surrounding Chihuahuan dark-soil habitat. We used field experiments to assess S. undulatus anti-predator behaviour in white-sand versus dark-soil habitats, and used laboratory assays to determine whether behavioural differences could be mediated by hormonal regulation. Overall, we found that white-sand lizards were less vigilant but more wary than their dark-soil counterparts; it took them longer to detect a simulated predator, but once detected they were more likely to retreat from their perches than dark-soil lizards. At the proximate level, differences in anti-predator behaviour could not be explained by differences in plasma hormone levels (corticosterone and testosterone); we detected elevated corticosterone for lizards in our stress treatment relative to control treatment, but found no differences between habitats in baseline or acute corticosterone levels. At the evolutionary level, we suggest that differences in anti-predator behaviour may be explained by differences across habitats in predation environment, habituation, and/or the cost of retreating. Our study implicates changes in predator community composition in mediating ecological divergence in behaviour.

Estrutura populacional de Kielmeyera rugosa Choisy (Clusiaceae) no Parque Nacional Serra de Itabaiana, Estado do Sergipe

Studies on structure, size and ontogenic stages are important to understand which factors influence population processes, regeneration and response to disturbances of a population. This study examined the structure of a population of Kielmeyera rugosa Choisy (Clusiaceae) in white sands habitat of Serra de Itabaiana, Sergipe State. Thirty 20 x 25 m plots were selected randomly selected, and their abundance of young and adult plants was recorded, as well as trunk circumference, crown height and number of stems per plant. The spatial distribution of young and adult population is aggregated, caused by their predisposition to form groups in localities with large availability of resources and favorable conditions. Another factor contributing to the aggregation is the anemochoric dispersion of the species. The study population had the highest number of individuals in lower classes of height, with few individuals in larger classes, indicating that the population is growing or in a process of self-regeneration. There are more individuals 2-3 meters high, due to burning or cutting. These events were not able to stop the recruitment process or reproduction of the species in the area, as observed by the lack of gaps in the classes of stem diameter.