cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.19969509
title: The role of terrestrial bromeliads in determining the spatial organization of plant life forms in a tropical coastal forest

description: ABSTRACT The interplay between plant-plant interactions and light heterogeneity in the understory of tropical forests has rarely been examined. We aimed to identify the relative importance of the understory light environment and terrestrial bromeliads in explaining the abundance and spatial organization of different plant life forms along a coastal forest gradient from seashore inland in southeastern Brazil. We estimated the abundance of various life forms (herbs, woody plants, bromeliads, climbers, and palms) and the degree of light availability using hemispherical photographs in 165 plots (1 m2) within a 1.75 ha site. We used ordination methods, partial redundancy analysis (pRDA), spatial filtering using Moran’s eigenvector mapping, and Moran’s I splines. Forest cover was highly heterogeneous, but did not explain variation in abundance of life forms. Spatially, bromeliads were negatively associated with woody saplings, herbs and climbing plants at scales between 5-20 m, while the distance to seashore was found to be unrelated to these patterns. Our findings revealed that terrestrial bromeliads play an important role in the spatial organization of various life forms near the forest floor. Overall, the presence of terrestrial bromeliads and the plant area index better explained the understory vegetation than forest cover and distance to seashore.
DOI: 10.6084/m9.figshare.19969509.v1
title: The role of terrestrial bromeliads in determining the spatial organization of plant life forms in a tropical coastal forest

description: ABSTRACT The interplay between plant-plant interactions and light heterogeneity in the understory of tropical forests has rarely been examined. We aimed to identify the relative importance of the understory light environment and terrestrial bromeliads in explaining the abundance and spatial organization of different plant life forms along a coastal forest gradient from seashore inland in southeastern Brazil. We estimated the abundance of various life forms (herbs, woody plants, bromeliads, climbers, and palms) and the degree of light availability using hemispherical photographs in 165 plots (1 m2) within a 1.75 ha site. We used ordination methods, partial redundancy analysis (pRDA), spatial filtering using Moran’s eigenvector mapping, and Moran’s I splines. Forest cover was highly heterogeneous, but did not explain variation in abundance of life forms. Spatially, bromeliads were negatively associated with woody saplings, herbs and climbing plants at scales between 5-20 m, while the distance to seashore was found to be unrelated to these patterns. Our findings revealed that terrestrial bromeliads play an important role in the spatial organization of various life forms near the forest floor. Overall, the presence of terrestrial bromeliads and the plant area index better explained the understory vegetation than forest cover and distance to seashore.
DOI: 10.6084/m9.figshare.19969511
title: Phytoremediation of arsenic-contaminated water: the role of antioxidant metabolism of Azolla caroliniana Willd. (Salviniales)

description: ABSTRACT Phytoremediation has proven to be an efficient technology for removing arsenic (As) from water, but the plants used in this process need to be tolerant to the damage caused by As. The toxic effect of As on growth and functioning of the antioxidant system was studied in individual plants of Azolla caroliniana exposed to five concentrations of As (0.0, 0.25, 0.5, 1.0 and 1.5 mg L-1) for the course of five days. Growth, As absorption, enzymatic activity, total and non-protein thiols and anthocyanin content were assessed. Azolla caroliniana was able to take up large amounts of the pollutant, reaching As concentrations of 386.1 µg g-1 dry weight without saturating the absorption mechanism. The tolerance index and the growth of A. caroliniana decreased with the increased As uptake. Superoxide dismutase, peroxidases, catalases and glutathione reductase activities increased at lower doses of As and subsequently declined with higher concentrations, whereas ascorbate peroxidase activity was reduced in all treatments. Unlike the enzymatic defence system, anthocyanin and thiol content increased consistently in all treatments and showed a positive correlation with As concentration. Therefore, the increased synthesis of non-enzymatic antioxidants is most likely the main factor responsible for the high As tolerance of A. caroliniana.
DOI: 10.6084/m9.figshare.19969511.v1
title: Phytoremediation of arsenic-contaminated water: the role of antioxidant metabolism of Azolla caroliniana Willd. (Salviniales)

description: ABSTRACT Phytoremediation has proven to be an efficient technology for removing arsenic (As) from water, but the plants used in this process need to be tolerant to the damage caused by As. The toxic effect of As on growth and functioning of the antioxidant system was studied in individual plants of Azolla caroliniana exposed to five concentrations of As (0.0, 0.25, 0.5, 1.0 and 1.5 mg L-1) for the course of five days. Growth, As absorption, enzymatic activity, total and non-protein thiols and anthocyanin content were assessed. Azolla caroliniana was able to take up large amounts of the pollutant, reaching As concentrations of 386.1 µg g-1 dry weight without saturating the absorption mechanism. The tolerance index and the growth of A. caroliniana decreased with the increased As uptake. Superoxide dismutase, peroxidases, catalases and glutathione reductase activities increased at lower doses of As and subsequently declined with higher concentrations, whereas ascorbate peroxidase activity was reduced in all treatments. Unlike the enzymatic defence system, anthocyanin and thiol content increased consistently in all treatments and showed a positive correlation with As concentration. Therefore, the increased synthesis of non-enzymatic antioxidants is most likely the main factor responsible for the high As tolerance of A. caroliniana.
DOI: 10.6084/m9.figshare.19969512.v1
title: Temporal evaluation of the Conservation Priority Index for medicinal plants

description: ABSTRACT We investigated, through a temporal comparison, the extraction of non-timber forest resources by quantitatively analyzing the Conservation Priority Index (CPI). The study focused on the Fulni-ô Indigenous Territory, in the municipality of Águas Belas, PE (Northeast Brazil), which is characterized by caatinga vegetation (seasonal dry forest). Information on the availability of the exploited resources and the reported use of the species were obtained from vegetation sampling and semi-structured interviews, respectively. Our results demonstrated a reduction in species richness overtime, which may be due to continued resource extraction in the area, and that some species with low densities were even more affected. The species reported as being at high risk in the current study apparently did not differ from their status in the previous study, which supports the idea that these species are most evident in this situation more for their high potential of use than for their high densities. When we associate these events together with the disappearance of some rare species, we can conclude that the CPI was not efficient in predicting changes, and that the combination of variables used with the biological variables of the species needs to be adjusted.
DOI: 10.6084/m9.figshare.19969512
title: Temporal evaluation of the Conservation Priority Index for medicinal plants

description: ABSTRACT We investigated, through a temporal comparison, the extraction of non-timber forest resources by quantitatively analyzing the Conservation Priority Index (CPI). The study focused on the Fulni-ô Indigenous Territory, in the municipality of Águas Belas, PE (Northeast Brazil), which is characterized by caatinga vegetation (seasonal dry forest). Information on the availability of the exploited resources and the reported use of the species were obtained from vegetation sampling and semi-structured interviews, respectively. Our results demonstrated a reduction in species richness overtime, which may be due to continued resource extraction in the area, and that some species with low densities were even more affected. The species reported as being at high risk in the current study apparently did not differ from their status in the previous study, which supports the idea that these species are most evident in this situation more for their high potential of use than for their high densities. When we associate these events together with the disappearance of some rare species, we can conclude that the CPI was not efficient in predicting changes, and that the combination of variables used with the biological variables of the species needs to be adjusted.
DOI: 10.6084/m9.figshare.19969514
title: Morphoanatomy of nectaries of Chamaecrista (L.) Moench sections Chamaecrista , Caliciopsis and Xerocalyx (Leguminosae: Caesalpinioideae)

description: ABSTRACT Nectaries are specialized structures that secrete nectar. Several species of Chamaecrista possess nectaries on the petiole, which have been shown to vary widely in morphology and the chemical nature of their secretion. However, a comprehensive investigation of the nectaries of the clade formed by sect. Chamaecrista, Caliciopsis and Xerocalyx has yet to be performed. Our study aimed to confirm whether or not the leaf glands of species of this clade are in fact nectaries, determine the chemical nature of their secretion and expand the morphoanatomical database on leaf nectaries in Chamaecrista with the intention of contributing to the taxonomy and phylogeny of the genus. Samples from herbarium and field-collected material were subjected to standard methods for light and scanning electron microscopy. Four different forms of nectaries were observed: urceolate, patelliform, verruciform and cupuliform. The nectaries were found to comprise a single-layered epidermis, nectary parenchyma, subnectary parenchyma and vascularization. Polysaccharides, lipids, phenolic compounds and proteins were detected in secretions. Although anatomical similarities were observed among the studied species, their morphology differed. Moreover, the glands are indeed nectaries and are similar to those observed in other species of the genus Chamaecrista. These data hold potential taxonomic usefulness for the studied sections.
DOI: 10.6084/m9.figshare.19969514.v1
title: Morphoanatomy of nectaries of Chamaecrista (L.) Moench sections Chamaecrista , Caliciopsis and Xerocalyx (Leguminosae: Caesalpinioideae)

description: ABSTRACT Nectaries are specialized structures that secrete nectar. Several species of Chamaecrista possess nectaries on the petiole, which have been shown to vary widely in morphology and the chemical nature of their secretion. However, a comprehensive investigation of the nectaries of the clade formed by sect. Chamaecrista, Caliciopsis and Xerocalyx has yet to be performed. Our study aimed to confirm whether or not the leaf glands of species of this clade are in fact nectaries, determine the chemical nature of their secretion and expand the morphoanatomical database on leaf nectaries in Chamaecrista with the intention of contributing to the taxonomy and phylogeny of the genus. Samples from herbarium and field-collected material were subjected to standard methods for light and scanning electron microscopy. Four different forms of nectaries were observed: urceolate, patelliform, verruciform and cupuliform. The nectaries were found to comprise a single-layered epidermis, nectary parenchyma, subnectary parenchyma and vascularization. Polysaccharides, lipids, phenolic compounds and proteins were detected in secretions. Although anatomical similarities were observed among the studied species, their morphology differed. Moreover, the glands are indeed nectaries and are similar to those observed in other species of the genus Chamaecrista. These data hold potential taxonomic usefulness for the studied sections.
DOI: 10.6084/m9.figshare.19969517
title: Araceae of Grumari restinga: contribution to the conservation of the flora of Rio de Janeiro State, Brazil

description: ABSTRACT This study surveyed species of the family Araceae in Grumari restinga, located in the metropolitan region of the city of Rio de Janeiro, Brazil. We aimed to: i) evaluate the contribution of a single locality (Grumari restinga) to regional conservation (Rio de Janeiro State) of Araceae; and ii) compare the distribution of species of Araceae among restingas of the state. We calculated the extent of occurrence and the area of occupancy in the entire state for eight species of Araceae found in Grumari,and performed a similarity analysis among restingas. Our data demonstrate that the extent of occurrences for Anthurium augustinum, A. coriaceum and A. maricense are influenced by Grumari because this area is the boundary of their known distribution in the state. Grumari did not have an influence on the distribution of the other studied species. We found Anthurium coriaceum, A. luschnathianum and Philodendron crassinervium to exhibit unusual habits as terrestrial plants in sandy soil. The similarity analysis identified six groups of Araceae, four of which are related to the distance from adjacent forests. We demonstrated that this small conservation unit represents a key locality in the preservation of natural populations of species of Araceae in Rio de Janeiro State.
DOI: 10.6084/m9.figshare.19969517.v1
title: Araceae of Grumari restinga: contribution to the conservation of the flora of Rio de Janeiro State, Brazil

description: ABSTRACT This study surveyed species of the family Araceae in Grumari restinga, located in the metropolitan region of the city of Rio de Janeiro, Brazil. We aimed to: i) evaluate the contribution of a single locality (Grumari restinga) to regional conservation (Rio de Janeiro State) of Araceae; and ii) compare the distribution of species of Araceae among restingas of the state. We calculated the extent of occurrence and the area of occupancy in the entire state for eight species of Araceae found in Grumari,and performed a similarity analysis among restingas. Our data demonstrate that the extent of occurrences for Anthurium augustinum, A. coriaceum and A. maricense are influenced by Grumari because this area is the boundary of their known distribution in the state. Grumari did not have an influence on the distribution of the other studied species. We found Anthurium coriaceum, A. luschnathianum and Philodendron crassinervium to exhibit unusual habits as terrestrial plants in sandy soil. The similarity analysis identified six groups of Araceae, four of which are related to the distance from adjacent forests. We demonstrated that this small conservation unit represents a key locality in the preservation of natural populations of species of Araceae in Rio de Janeiro State.
DOI: 10.6084/m9.figshare.5792637.v1
title: Crop size influences pre-dispersal seed predation in the Brazilian Cerrado

description: ABSTRACT Many pre-dispersal seed predators are specialized insects that rely on seeds for larval development. These insects may respond to the amount of seeds produced by a plant (i.e. crop size), increasing the proportion of seeds damaged with increases in seed numbers. Large seeds have more resources and spend more time in plants to complete their development and are probably more prone to be preyed on by those insects than small seeds. Here I tested how crop size and seed mass influence pre-dispersal seed predation in plants from the Cerrado savannas of Brazil. I related plant crop size to pre-dispersal seed predation for Xylopia aromatica and Erythroxylum pelleterianum. A literature review was performed to test if seed mass may explain among-species differences in pre-dispersal seed predation. Pre-dispersal losses increased proportionally to crop size in the two species investigated, but some species show positive or no density-dependent seed predation in literature, indicating that seed losses are not a simple function of crop sizes. Seed mass did not explain pre-dispersal seed loss differences among 14 species with data available. Pre-dispersal losses are often small and probably less important than seed dispersal and establishment limitation for plant recruitment in Cerrado savannas.
DOI: 10.6084/m9.figshare.5792637
title: Crop size influences pre-dispersal seed predation in the Brazilian Cerrado

description: ABSTRACT Many pre-dispersal seed predators are specialized insects that rely on seeds for larval development. These insects may respond to the amount of seeds produced by a plant (i.e. crop size), increasing the proportion of seeds damaged with increases in seed numbers. Large seeds have more resources and spend more time in plants to complete their development and are probably more prone to be preyed on by those insects than small seeds. Here I tested how crop size and seed mass influence pre-dispersal seed predation in plants from the Cerrado savannas of Brazil. I related plant crop size to pre-dispersal seed predation for Xylopia aromatica and Erythroxylum pelleterianum. A literature review was performed to test if seed mass may explain among-species differences in pre-dispersal seed predation. Pre-dispersal losses increased proportionally to crop size in the two species investigated, but some species show positive or no density-dependent seed predation in literature, indicating that seed losses are not a simple function of crop sizes. Seed mass did not explain pre-dispersal seed loss differences among 14 species with data available. Pre-dispersal losses are often small and probably less important than seed dispersal and establishment limitation for plant recruitment in Cerrado savannas.
DOI: 10.6084/m9.figshare.19969518
title: Pollen morphology of Waltheria L. (Malvaceae-Byttnerioideae) from Bahia, Brazil

description: ABSTRACT Waltheria encompasses about 60 species distributed in Brazil and Mexico. To improve the palynology of the genus, we analyzed 14 species occurring in the Brazilian State of Bahia. Pollen grains were acetolyzed and examined using light microscopy and scanning electron microscopy. Non-acetolyzed pollen grains were viewed by transmission electron microscopy. The results revealed two general pollen types based on exine ornamentation, such as reticulate and echinate, which are distinct with regard to (1) size and shape, (2) apertural type and number, (3) relative length of ectoapertures, and (4) thickening of the nexine compared to the sexine. An ultrastructural analysis of the pollen wall revealed a continuous foot layer and a compact and discontinuous endexine in most cases. The sexine consisted of heterogeneous columellae, which support a perforated semitectum (echinate type) or the semitectum was composed of perforations and muri-shaped thickening (reticulate type). These results confirm a high degree of pollen dimorphism in Waltheria associated with heterostyly.
DOI: 10.6084/m9.figshare.19969518.v1
title: Pollen morphology of Waltheria L. (Malvaceae-Byttnerioideae) from Bahia, Brazil

description: ABSTRACT Waltheria encompasses about 60 species distributed in Brazil and Mexico. To improve the palynology of the genus, we analyzed 14 species occurring in the Brazilian State of Bahia. Pollen grains were acetolyzed and examined using light microscopy and scanning electron microscopy. Non-acetolyzed pollen grains were viewed by transmission electron microscopy. The results revealed two general pollen types based on exine ornamentation, such as reticulate and echinate, which are distinct with regard to (1) size and shape, (2) apertural type and number, (3) relative length of ectoapertures, and (4) thickening of the nexine compared to the sexine. An ultrastructural analysis of the pollen wall revealed a continuous foot layer and a compact and discontinuous endexine in most cases. The sexine consisted of heterogeneous columellae, which support a perforated semitectum (echinate type) or the semitectum was composed of perforations and muri-shaped thickening (reticulate type). These results confirm a high degree of pollen dimorphism in Waltheria associated with heterostyly.
DOI: 10.6084/m9.figshare.7102763
title: Reproductive phenology and germination of Eleocharis laeviglumis R. Trevis. & Boldrini (Cyperaceae)

description: ABSTRACT Aquatic macrophytes are important components of freshwater ecosystems, of which Cyperaceae is the most diverse family. Many species of Cyperaceae form dense populations along lake margins of the southern coast of Brazil, but little is known about their sexual reproductive strategies. We characterized the reproductive life cycle of Eleocharis laeviglumis, an abundant emergent macrophyte of coastal wetlands in southern Brazil, by assessing its reproductive phenophases and estimating the number of its flowers and potentially viable fruits per inflorescence in a natural population. We also tested seed germinability and vigor for a period of four months during a single reproductive season. The species possesses dichogamous and protogynous spikelets with an average duration of 34 days (pre-anthesis, 1.7 d; anthesis, 6.9 d; fruit maturation, 22.3 d; fruit dispersion, 3.2 d). More than half of the flowers (62.2 %) developed into fruits, while only 5.5 % of the seeds germinated. Germinability and vigor decreased during the reproductive season. Some culms probably originate from asexual reproduction or sexual reproduction of clones. For restoration purposes, we suggest that E. laeviglumis should be propagated by sowing seeds collected at the beginning of the reproductive season, along with the transplantation of rhizomes.
DOI: 10.6084/m9.figshare.7102763.v1
title: Reproductive phenology and germination of Eleocharis laeviglumis R. Trevis. & Boldrini (Cyperaceae)

description: ABSTRACT Aquatic macrophytes are important components of freshwater ecosystems, of which Cyperaceae is the most diverse family. Many species of Cyperaceae form dense populations along lake margins of the southern coast of Brazil, but little is known about their sexual reproductive strategies. We characterized the reproductive life cycle of Eleocharis laeviglumis, an abundant emergent macrophyte of coastal wetlands in southern Brazil, by assessing its reproductive phenophases and estimating the number of its flowers and potentially viable fruits per inflorescence in a natural population. We also tested seed germinability and vigor for a period of four months during a single reproductive season. The species possesses dichogamous and protogynous spikelets with an average duration of 34 days (pre-anthesis, 1.7 d; anthesis, 6.9 d; fruit maturation, 22.3 d; fruit dispersion, 3.2 d). More than half of the flowers (62.2 %) developed into fruits, while only 5.5 % of the seeds germinated. Germinability and vigor decreased during the reproductive season. Some culms probably originate from asexual reproduction or sexual reproduction of clones. For restoration purposes, we suggest that E. laeviglumis should be propagated by sowing seeds collected at the beginning of the reproductive season, along with the transplantation of rhizomes.