Search

Endemism and rarity have long intrigued scientists. We focused on a rare endemic and critically-endangered species in a global biodiversity hotspot, Grevillea thelemanniana (Proteaceae). We carried out plant and soil analyses of four Proteaceae, including G. thelemanniana, and combined these with glasshouse studies. The analyses related to hydrology and plant water relations as well as soil nutrient concentrations and plant nutrition, with an emphasis on sodium (Na) and calcium (Ca). The local hydrology and matching plant traits related to water relations partially accounted for the distribution of the four Proteaceae. What determined the rarity of G. thelemanniana, however, was its accumulation of Ca. Despite much higher total Ca concentrations in the leaves of the rare G. thelemanniana than in the common Proteaceae, very few Ca crystals were detected in epidermal or mesophyll cells. Instead of crystals, G. thelemanniana epidermal cell vacuoles contained exceptionally high concentrations of noncrystalline Ca. Calcium ameliorated the negative effects of Na on the very salt-sensitive G. thelemanniana. Most importantly, G. thelemanniana required high concentrations of Ca to balance a massively accumulated feeding-deterrent carboxylate, trans-aconitate. This is the first example of a calcicole species accumulating and using Ca to balance accumulation of an antimetabolite.

Species from OCBILs (old, climatically buffered, infertile landscapes) are expected to exhibit reduced dispersability, linked to long-term stable environmental conditions. We tested the prediction of limited dispersability in plant communities in campo rupestre, a megadiverse OCBIL grassland. In a field experiment, we sampled sticky and funnel traps for 12 months along paired preserved and disturbed plots to estimate and compare annual seed density and richness. Our community-level seed rain assessment suggested widespread seed limitation in both preserved and disturbed areas, expressed by the low seed density in traps (average of 2.6 seeds/m2/day) and remarkably low seed density found for 90% of the morphospecies. Although seed density in campo rupestre was much lower than for other grasslands, species richness (92 seed morphospecies) was the highest reported in the literature. Higher seed density and species richness were captured in funnel traps, especially during the rainy season. Approximately 32% of morphospecies were registered exclusively in disturbed plots and 25% exclusively in preserved plots. This limited seed dispersability is of particular relevance for a better understanding of seed ecology and resilience in campo rupestre and may partially explain the poor recovery of these disturbed areas after soil removal.

Herbivory is ubiquitous. Despite being a potential driver of plant distribution and performance, herbivory remains largely undocumented. Some early attempts have been made to review, globally, how much leaf area is removed through insect feeding. Kozlov et al., in one of the most comprehensive reviews regarding global patterns of herbivory, have compiled published studies regarding foliar removal and sampled data on global herbivory levels using a standardized protocol. However, in the review by Kozlov et al., only 15 sampling sites, comprising 33 plant species, were evaluated in tropical areas around the globe. In Brazil, which ranks first in terms of plant biodiversity, with a total of 46,097 species, almost half (43%) being endemic, a single data point was sampled, covering only two plant species. In an attempt to increase knowledge regarding herbivory in tropical plant species and to provide the raw data needed to test general hypotheses related to plant–herbivore interactions across large spatial scales, we proposed a joint, collaborative network to evaluate tropical herbivory. This network allowed us to update and expand the data on insect herbivory in tropical and temperate plant species. Our data set, collected with a standardized protocol, covers 45 sampling sites from nine countries and includes leaf herbivory measurements of 57,239 leaves from 209 species of vascular plants belonging to 65 families from tropical and temperate regions. They expand previous data sets by including a total of 32 sampling sites from tropical areas around the globe, comprising 152 species, 146 of them being sampled in Brazil. For temperate areas, it includes 13 sampling sites, comprising 59 species. Thus, when compared to the most recent comprehensive review of insect herbivory (Kozlov et al.), our data set has increased the base of available data for the tropical plants more than 460% (from 33 to 152 species) and the Brazilian sampling was increased 7,300% (from 2 to 146 species). Data on precise levels of herbivory are presented for more than 57,000 leaves worldwide. There are no copyright restrictions. Please cite this paper when using the current data in publications; the authors request to be informed how the data is used in the publications.

Dry grasslands of the Northwestern Mediterranean Basin are seminatural species‐rich ecosystems, composed of many annual species and some structuring perennial species. As these grasslands have been used as rangelands for centuries, human management (grazing; fire regimes) is one of their main ecological and evolutionary drivers, along with the Mediterranean climate. Despite EU conservation policy, damage to such grasslands still occurs and efficient ecological restoration is needed. This article reviews restoration constraints, effective techniques, and research perspectives for restoring them in the light of their ecological characteristics. Major restoration constraints specifically include (1) a poor contribution of the internal (seed bank) and external (seed rain) species pools, and (2) low establishment of some perennial species. The latter may be the result of the low seed quantity or quality of perennial species, stochastic or extended droughts, high soil nutrient content that may lead to competition (e.g. between weed and target species), inappropriate grazing management or fire regimes leading to shrub encroachment, or the death of target species seedlings in early stages of restoration. Successful restoration techniques include seeding, transplanting, hay transfer, and timely soil transfer, all of which have to be adapted to regional plant phenology and to local Mediterranean climate. They must be combined with appropriate grazing or fire management. Their success may depend on years with particular rainfall amounts or patterns or on particular target plant species. We discuss research perspectives contributing to a better understanding of seed dispersal, seedling recruitment, and soil processes and suggest the benefits of using ecosystem engineer species.

Global sustainability rests on a myriad of benefits provided by natural ecosystems that support human livelihoods and well-being, from biodiversity persistence to climate regulation. The undeniable importance of conserving tropical forests has drawn most of the conservation spotlight towards it. However, open ecosystems such as the Brazilian Campo Rupestre (rupestrian grassland), have been historically overlooked despite their high diversity and key associated ecosystem services. We highlight major current threats to the persistence of the Campo Rupestre emphasizing its ecological, social, cultural, geo-environmental, and economic importance. We call attention to the importance of the Campo Rupestre as a reservoir of biodiversity and ecosystem services and offer priority actions that resulted from discussions involving scientists, industry representatives, environmental managers, and other members of civil society. Proposed actions include efforts related to ecological restoration, sustainable ecotourism, protection of traditional ecological knowledge, identification of emerging research questions, and development of tailored public policies. Such issues are integrated into a framework that collectively represents a road map to safeguard the Campo Rupestre from further degradation and steer its historical overexploitation towards sustainable management. Safeguarding the future of non-forest biomes like this poses a challenge to current paradigms of nature conservation. By establishing priorities and guidelines, we propose an actionable plan, which we hope can support informed decision-making policy towards a sustainable use of the Campo Rupestre. Long Term Ecological Research PELD-CRSC-17 Conselho Nacional de Pesquisas CNPq/MCTI Fundação de Amparo à Pesquisa do Estado de São Paulo 2013/50155-0, 2010/51307-0, 2019/07773-1

International audience

Seed dispersal has key implications for community dynamics and restoration ecology. However, estimating seed rain (the number and diversity of seeds arriving in a given area) is challenging, and the lack of standardization in measurement prevents cross-site comparisons. Seed trap effectiveness and accuracy of seed sorting methods are key components of seed rain estimates in need of standardization. We propose and describe a standardized protocol for evaluating the effectiveness of two seed trap types (sticky and funnel traps) and the accuracy of a seed sorting method. We used widely available seeds (arugula, quinoa, sesame and sunflower) to produce a gradient of seed size, weight and colour. Proof-of-concept was tested in a tropical grassland, where traps were set for 30 days. Our results suggest that we underestimate dispersal of seeds with less than 2 mm width that can be easily mistaken for debris and soil particles or that fail to adhere to sticky traps. Seeds on sticky traps may be more vulnerable to removal by wind and rain, whereas seeds in funnel traps are more susceptible to decay. We found no evidence of observer bias on seed sorting for funnel trap samples. However, accuracy on seed sorting for funnel trap samples tended to decline for seeds with less than 2 mm width, suggesting a size-dependence in seed retrieval success. Our standardized protocol addressing trap effectiveness and seed sorting methods will increase the reliability of data obtained in seed rain studies and allow more reliable comparisons between datasets.

Larger flowers greatly increase among-individual pollen exchange within populations. However, water costs associated to transpirational cooling also increase with increasing flower size. Overall, the interplay between pollen and resource limitation determines the intensity of selection on flower size and this process is mostly dependent on gender and ecological context. To examine how pollinators and water use affect flower size, we determined corolla transpiration, pollen limitation, and selection through male and female fitness in two Kielmeyera species from the Brazilian cerrado flowering at different seasons. Hand-pollination experiments suggested pollen limitation through female fitness in both species, but K. coriacea showed lower limitation levels than K. regalis. For male fitness, the percentage of pollen removal was 1.5-times higher in K. coriacea. Higher air temperature and water deficit during flowering season of K. coriacea resulted in 4-fold higher corolla transpiration rates compared to K. regalis. Selection on flower size through male function was positive and significantly higher than selection through female components in both species. We also detected stabilizing selection in K. coriacea and positive selection in K. regalis on flower size through seed number. Our results suggest that selection on flower size in K. coriacea was mainly limited by water, whereas in K. regalis it was more limited by pollen. We demonstrate that differences in pollen and abiotic resource limitation determine gender-specific selection on flower size.

The extent of specialization/generalization continuum in fruit-frugivore interactions at the individual level remains poorly explored. Here, we investigated the interactions between the Neotropical treelet Miconia irwinii (Melastomataceae) and its avian seed dispersers in Brazilian campo rupestre. We built an individual-based network to derive plant degree of interaction specialization regarding disperser species. Then, we explored how intraspecific variation in interaction niche breadth relates to fruit availability on individual plants in varying densities of fruiting conspecific neighbors, and how these factors affect the quantity of viable seeds dispersed. We predicted broader interaction niche breadths for individuals with larger fruit crops in denser fruiting neighborhoods. The downscaled network included nine bird species and 15 plants, which varied nearly five-fold in their degree of interaction specialization. We found positive effects of crop size on visitation and fruit removal rates, but not on degree of interaction specialization. Conversely, we found that an increase in the density of conspecific fruiting neighbors both increased visitation rate and reduced plant degree of interaction specialization. We suggest that tracking fruit-rich patches by avian frugivore species is the main driver of density-dependent intraspecific variation in plants' interaction niche breadth. Our study shed some light on the overlooked fitness consequences of intraspecific variation in interaction niches by showing that individuals along the specialization/generalization continuum may have their seed dispersed with similar effectiveness. Our study exemplifies how individual-based networks linking plants to frugivore species that differ in their seed dispersal effectiveness can advance our understanding of intraspecific variation in the outcomes of fruit-frugivore interactions.

International audience; Questions: Anthropogenic disturbances are known to be followed by extremely poor recovery in edaphic grasslands. However, the role of interactions with diaspore predators and secondary dispersers, which compose the dispersal filter and modulate plant community recovery, has been overlooked. We performed field experiments to investigate how soil disturbances affect diaspore interactions with the ground‐foraging fauna to better understand how disturbance influences regeneration potential.Location: Campo rupestre vegetation, megadiverse edaphic grasslands, southeastern Brazil.Methods: We used diaspores from five native species to compare removal rates between disturbed (top soil removal) and preserved sites; we also controlled invertebrate and vertebrate access to determine their role. In addition, we assessed differences in the diaspore removal effectiveness (DRE) and the structure of animal–diaspore interactions through network based‐approach.Results: For three species, the average diaspore removal rates was relatively high (between 30% and 70%). Invertebrates were the most common removal agents in both disturbed and preserved sites. Interactions with foraging fauna and removal rates were 20% smaller in disturbed sites. Considering all diaspore removal events in disturbed sites, 24% resulted in the displacement from disturbed to preserved sites, but no diaspore was transported from preserved to disturbed ones. The animal–diaspore network was exclusively composed by ant–diaspore interactions and was more diverse and robust in preserved sites compared with disturbed ones. Seed predator ants (Pheidole and Dorymyrmex) were more common in disturbed sites. Furthermore, significant differences were found in the DRE between ant species and site types, suggesting specificity in the provision of dispersal services.Conclusions: Topsoil removal affected removal proportions, DRE and ant–diaspore interaction network structure. The lack of diaspore dispersal towards disturbed sites indicates that soil removal affects secondary seed removal dynamics, impeding recovery potential. Disturbance negatively affected diaspore fate by reshaping interactions with ground‐foraging secondary seed dispersers and predators, constraining the development of seed bank and thus impacting upon vegetation dynamics and resilience.

The balance between the costs and benefits of fleshy fruit production depends on the feeding behavior of their seed dispersers, which might effectively disperse seeds to farther areas or drop beneath parent plants some diaspores they handle during frugivory bouts. Nevertheless, the consequences of variation in fruit handling by primary seed dispersers on the secondary removal of diaspores remains poorly understood. We conducted a field study to determine how variation in fruit handling by avian frugivores affects short-term secondary removal of Miconia irwinii (Melastomataceae) diaspores by the ground-dwelling fauna in campo rupestre vegetation, southeastern Brazil. We conducted factorial experiments manipulating: (1) different outcomes of primary fruit/seed removal by birds, (2) distances of diaspore deposition from conspecifics, and (3) the access of ants and vertebrates to diaspores. We showed that secondary removal of diaspores was highly variable at the population scale, with an overall low removal rate by the ground-dwelling fauna (13% seeds, 19% fruits). However, we found that gut-passed seeds embedded in bird feces were less removed than seeds expelled from fruits. Gut-passed seeds were more likely to be removed by ant species acting as secondary dispersers, whereas pulp-free seeds dropped by birds were likely to interact with potential seed predators, including ants and rodents. We found no clear effect of dispersal from parent plant vicinity on seed removal, but fruit removal was significantly higher near parent plants. Partially defleshed fruits were more removed than intact fruits. The removal of fruits by ant and vertebrate rescuers, including lizards and birds, might reduce the costs of interactions with less effective dispersers that drop partially defleshed fruits under parent plants. Our study highlights that variation in fruit handling by primary avian seed dispersers mediate subsequent interactions among discarded diaspores and ground-dwelling animals, potentially affecting final seed fates. Moreover, we argue that escape-related benefits of dispersal can be contingent on how primary dispersers handle and discard seeds.

International audience; 1. Ontogenetic shifts in plants are ubiquitous, but their ecological and evolutionary significance remain largely unknown. Juveniles have few opportunities to accumulate sufficient biomass to withstand damage, whereas adults allocate resources to reproduction. Thus, age-specific environmental filters are expected to drive selection towards specific resource-investment strategies for each developmental stage. 2. We tested whether species exhibited strategies that favour faster rates of biomass accumulation during early developmental stages to cope with vulnerability, shifting towards habitat-dependent strategies to optimise resource acquisition and use later on. We also hypothesised that juveniles exhibit greater intraspecific variability of strategies than adults, as a result of continuous filtering of traits throughout the plant's development towards adulthood. 3. We measured key leaf traits-leaf area (LA), leaf dry matter content (LDMC) and specific leaf area (SLA)-and calculated scores for competitor (C), stress-tolerator (S), ruderal (R) strategies of the CSR system for juveniles of 54 species and conspecific adults of 27 species naturally occurring either in unproductive (grassland) or productive (forest) habitats. 4. Juveniles exhibited higher SLA and LA and lower LDMC, and thus a more R-strategy in both habitats when compared with adults, but were not necessarily "R" in absolute terms. We also found smaller intraspecific variation for the R-strategy in adults compared with juveniles in both habitats, whereas the variation of the other strategies was habitat dependent. 5. Ontogenetic shifts in ecological strategies appear to have been selected as a response to ontogeny-dependent filters. Thus, strategies that favour less costly leaves and faster growth rates (relatively R-selected) in juveniles shift towards C and/or S strategies in adulthood, depending on habitat productivity. Nevertheless, habitat-dependent specialisation seems to be a major driver of ecological strategy selection in juveniles. Our study reveals ontogeny-dependent strategies, offering a new approach to integrate plant development and functional specialisation.

Este estudo trata as espécies de Blechnaceae encontradas nas formações ferríferas da Serra dos Carajás, estado do Pará, com descrições, ilustrações, distribuição geográfica e comentários sobre os táxons. Na área estudada foram registrados três gêneros e sete espécies: Blechnum areolatum, B. heringeri, B. longipilosum, B. occidentale, B. polypodioides, Neoblechnum brasiliense e Telmatoblechnum serrulatum. This study addressed the Blechnaceae species recorded in ferruginous formations of Serra dos Carajás, Pará state, presenting descriptions, illustrations, geographical distribution, and comments about the taxa. In the studied area, three genera and seven species were recorded: Blechnum areolatum, B. heringeri, B. longipilosum, B. occidentale, B. polypodioides, Neoblechnum brasiliense and Telmatoblechnum serrulatum.

Resumo Este estudo trata dos táxons de Dennstaedtiaceae encontrados nas formações ferríferas da Serra dos Carajás, estado do Pará, com descrições, ilustrações, distribuição geográfica e comentários. Na área estudada foi registrada apenas Pteridium arachnoideum. Abstract This study addressed the Dennstaedtiaceae taxa recorded in ferruginous formations of Serra dos Carajás, Pará state, with descriptions, illustrations, geographical distribution, and comments. In the study area only one species was recorded: Pteridium arachnoideum.

Resumo Este estudo trata dos táxons de Thelypteridaceae encontrados nas formações ferríferas da Serra dos Carajás, estado do Pará, com descrições, ilustrações, distribuição geográfica e comentários. Na área estudada foram registrados quatro gêneros e sete espécies: Christella hispidula, Cyclosorus interruptus, Goniopteris abrupta, G. pennata, G. tetragona, G. tristis e Meniscium maxonianum.

Resumo Este estudo trata dos táxons de Aspleniaceae encontrados nas formações ferríferas da Serra dos Carajás, estado do Pará, com descrições, ilustrações, distribuição geográfica e comentários. Na área estudada foram registrados um gênero e quatro espécies: Asplenium formosum, Asplenium salicifolium, Asplenium serratum, Asplenium stuebelianum. Abstract This study adressed the Aspleniaceae taxa recorded in ferruginous formations of Serra dos Carajás, Pará state, bringing descriptions, illustrations, geographical distribution, and comments. In the study area one genus and four species were recorded: Asplenium formosum, Asplenium salicifolium, Asplenium serratum, and Asplenium stuebelianum.

Resumo Este estudo trata os táxons de Cyatheaceae encontrados nas formações ferríferas da Serra dos Carajás, estado do Pará, com descrições, ilustrações, distribuição geográfica e comentários. Na área estudada foi registrada apenas Cyathea pungens. Abstract This study addressed the Cyatheaceae taxa recorded in ferruginous formations of Serra dos Carajás, Pará state, bringing descriptions, illustrations, geographical distribution, and comments. In the study area only one species was recorded: Cyathea pungens.

Isoetes serracarajensis and I. cangae, two new species from northern Brazil, are described, illustrated, and compared to similar species. Isoetes serracarajensis can be distinguished from other species by a set of characters including triangular to linear microphylls, a reniform-orbicular labium, a rudimentary velum covering up to 1/5 of the sporangial surface, dark brown to red-brown sporangia and verrucate megaspores (verrucae type 1). Isoetes cangae presents large microphylls, a reniform-orbicular labium, a rudimentary velum covering only up to 1/4 of the sporangium surface, hyaline sporangia and verrucate (verrucae type 2) to tuberculate megaspores (tubercles type 3). Based on the IUCN criteria, we suggest that Isoetes serracarajensis should be classified as vulnerable (VU) and Isoetes cangae included as critically endangered (CR).

Thelypteris indusiata is described as a new species from Amazonian Brazil. This species with 1-pinnate laminae and terminal pinnae that resemble lateral ones belongs to Thelypteris subgenus Goniopteris and resembles several other species, mainly T. poiteana, T. ghiesbreghtii, T. vivipara and T. platypes, but differs from these species mainly by the venation pattern and the indusiate sori.

This study presents taxonomic treatment of the species of Isoetaceae from Serra dos Carajás, Pará, Brazil. Two species occur in this locality (Isoetes cangae and I. serracarajensis). We provide descriptions, illustrations, images of the mega- and microspores, comments, distribution data and a key for these species as a contribution to the knowledge of the flora of the cangas from this area.

Resumo Este estudo trata dos táxons de Oleandraceae encontrados nas formações ferríferas da Serra dos Carajás, estado do Pará, com descrições, ilustrações, distribuição geográfica e comentários. Na área estudada foi registrada apenas Oleandra pilosa.