Rainforest Biome Research Articles

Effects of Phylloicus case removal on consumption of leaf litter from two Neotropical biomes (Amazon rainforest and Cerrado savanna)

Phylloicus (Trichoptera, Calamoceratidae) is a stream invertebrate widely distributed across Neotropical biomes, which larvae use allochthonous leaf litter as food resource and to build a case that offers protection against predation. Seasonal changes in leaf litter accumulation on the streambed may affect Phylloicus larvae due to variations in availability of food and case-building material; however, it is unclear how these two processes influence each other. We assessed how case removal affected leaf litter consumption by Phylloicus larvae from two Neotropical biomes (Amazon rainforest and Cerrado savanna), which were experimentally offered leaf litter of Goupia glabra and Maprounea guianensis (common riparian species from the rainforest and savanna biomes, respectively). Our treatments included (i) direct effect of case removal, where larvae had their case removed during the experiment; (ii) time-lag effect, where the case was removed and larvae were allowed to rebuild the case before starting the experiment; and (iii) control, where cases were not removed. Leaf litter consumption by Phylloicus was 9.16 ± 7.47 mg/mg on average, being higher in the savanna than in the rainforest experiment (possibly in relation to a higher difference between the rainforest stream temperature and the experimental temperature, which may have inhibited larval activity), and higher on M. guianensis than on G. glabra (most likely due to the higher leaf litter quality of the former species). Consumption was higher in the time-lag effect treatment than in the direct effect and control treatments, which could be explained by an increase in the larval energetic demand for case building.

Boronia (Rutaceae) is polyphyletic: Reinstating Cyanothamnus and the problems associated with inappropriately defined outgroups

AbstractThe monophyly of Boronia (Rutaceae) was tested using 134 accessions of 120 species belonging to 39 genera from subfamily Amyridoideae. Taxa included representatives of all eight sections of Boronia plus species of most genera in the two main clades related to Boronia that had been identified by earlier studies. These samples included a good representation of genera from both rainforest and sclerophyllous biomes. Maximum parsimony and Bayesian inference analyses were performed using three plastid markers (psbA‐trnH, trnL‐trnF, rbcL) and two nuclear ribosomal markers (ITS, ETS). Separate analyses of plastid and nuclear sequences using either maximum parsimony or Bayesian inference analyses recovered similar topologies. Apart from Boronia, the broad generic relationships of previous analyses were largely supported. Boronia is polyphyletic with section Cyanothamnus being more closely related to a large clade containing genera found in rainforest, including Melicope, Acronychia and their relatives. The remaining seven sections of Boronia formed a strongly supported and isolated group. Boronia sensu stricto is sister to a clade containing the Cyanothamnus‐Melicope‐Acronychia clade plus a clade containing Euodia, Zieria and other small genera found in rainforest or sclerophyllous communities. Issues with circumscriptions of ingroups and outgroups for previous analyses of Boronia and the complex relationship between Australasian genera found in rainforest and sclerophyllous communities are both discussed. Cyanothamnus is reinstated at generic level. Appropriate nomenclatural changes are made to transfer all currently recognised series, species, subspecies and varieties of Boronia sect. Cyanothamnus to the genus Cyanothamnus.

Phoracantha recurva (Coleoptera: Cerambycidae): First Report in the Atlantic Rainforest of Minas Gerais, Brazil

The expansion of the area planted with Eucalyptus species and the trade of its products in the world have been accompanied by accidental introduction of exotic insects. The genus Phoracantha Newman (Coleoptera: Cerambycidae), from Australia and New Guinea, has 40 borer species that use trees and freshly cut logs of the genus Angophora, Corymbia, and Eucalyptus. The objective of this report is to document the occurrence of P. recurva damaging weakened C. citriodora trees in an urban area of the Atlantic rainforest in Vicosa, Minas Gerais State, Brazil. Extensive feeding galleries and the presence of a P. recurva male adult were found in the trunks of weakened trees of C. citriodora logs in an area near the forest nursery of the Universidade Federal de Vicosa. This is the first report of this borer species in this climate zone of the Atlantic rainforest biome of Minas Gerais, Brazil. This suggests that P. recurva has high plasticity to establish in regions with different climatic conditions, being able to survive in most regions of Brazil. The record of P. recurva infesting C. citriodora trees in the Minas Gerais Atlantic rainforest region increases its distribution in Brazil. This knowledge is important in reducing or preventing its damage in Brazil.

The genus Cyclocephala Dejean (Coleoptera: Scarabaeidae: Dynastinae) in Brazil: diversity and spatio-temporal distribution

The genus Cyclocephala Dejean (Coleoptera, Scarabaeidae, Dynastinae) contains approximately 350 species and is found mainly in the Neotropical region. These species function in the cycling of organic matter, act as bioindicators of environmental quality, and some species are considered agricultural pests. This study attempted to analyze the spatio-temporal distribution and diversity of Cyclocephala species across five Brazilian biomes, and to understand the factors that influence their distribution. Climatic variables (temperature, humidity, and precipitation), spatial variables (latitude, longitude, and elevation), and the landscape composition around the sampling areas were evaluated. Insects were collected using light traps in areas of native vegetation in the Amazon, Cerrado, Atlantic Rainforest, Pampa, and Caatinga biomes. Sampling was carried out monthly from June 2015 to May 2016. A total of 5695 individuals across 38 species of Cyclocephala were collected, including five species recorded for the first time in Brazil. The Amazon biome contains the greatest species richness and abundance of Cyclocephala species among all studied biomes, with 73.68% of collected species being endemic to this biome. The richness and abundance of species in this genus were influenced by climatic factors, such as temperature (and its interactions with precipitation and relative humidity) and the interaction between precipitation and relative humidity, and by spatial factors, such as longitude, but not by the percentage of vegetation remaining in the landscape. Cyclocephala species showed seasonal abundances and aggregated distribution, which varied according to the climatic characteristics of each biome.

Vegetation and seed bank of an open-scrub bush restinga formation in the Southeastern coast of Brazil

Introduction: Restingas are coastal plain ecosystems located along Eastern Brazil, corresponding to about 5 000 km. The restinga vegetation is associated with the Atlantic rainforest biome and comprises four distinct main formation zones: coastal grasslands, shrublands, open-forests and marsh zones. Especially due to coastal urbanization, this is a threatened ecosystem that, through its different shrub formations, exhibits a unique mosaic as a result of the vegetation distribution in nuclei of different covering, physiognomy and floristic composition. Objective: We aimed to characterize the above and belowground composition of a conserved, non-flooded, open-scrub, nuclei (patches of bushes) formation of restinga in Linhares, ES, southeastern Brazil. Methods: The vegetation survey was conducted using the line intercept method. Diameter and height of the first six nuclei were measured in five transects separated by 50 m, totaling 30 nuclei up to 350 m away from the shore line. The phytosociology and Shannon Index of the aboveground vegetation community were calculated. In the same 30 nuclei, leaf litter and topsoil layer (15 x 15 x 10 cm) samples were collected to survey the viable seed bank, which was later placed in a greenhouse for germination and seedling identification. The Sørensen Similarity index (SSi) was used to compare the floristic composition between the leaf litter and topsoil layer seed banks. Nuclei volume and number of species were calculated as well. Results: In the aboveground vegetation, 54 plant species belonging to 32 families were identified, totaling 1 098 individuals. The nuclei showed a diversity (H') of 3.08 nats, and an average diameter of 11.5 m (s = 9.1), area of 526.4 m2 (s = 1 081.7), and height of 2.9 m (s = 1.1). Davilla flexuosa, followed by Smilax rufescens, presented the highest IVI (Importance Value Index). A total of 1 839 seedlings from 32 species and 19 families were identified in the seed bank. Enydra sessilis (Asteraceae) had the highest seed density (544), while the family with highest species richness was Cyperaceae. A low similarity between the vegetation surveyed and the seed bank composition was found (only 5 species in common, SSi = 0.10). Conclusions: The results indicate that a post-disturbance early community, established from the seed bank, would have a substantially different species composition, but with other potential species to restore vegetation over the long-term succession.

Diagrama ombrotérmico do bairro Camobi, Santa Maria, RS

Para o desenvolvimento das atividades humanas, o conhecimento detalhado das condições climáticas assume fundamental importância. Entretanto, em muitas áreas, há carência de informações sobre o assunto e os problemas ambientais intensificaram-se com a sedentarização do homem. Tais problemas ocorrem em diversos locais devido à carência de planejamento, ou seja, por deficiências no processo de gestão dos recursos naturais. No caso da cidade de Santa Maria, RS, as condições se agravam devido a sua localização peculiar, uma zona de transição entre os biomas Pampa e Mata Atlântica. No sentido de aumentar a disponibilidade de informações em relação ao clima e ecologia, o trabalho tem como objetivo estabelecer diagramas ombrotérmicos e identificar as curvas ômbricas e térmicas mensais para o bairro Camobi no município de Santa Maria, RS. A metodologia seguiu a proposta de Bagnouls e Gaussen (1963). Utilizaram-se dados obtidos no do período 2010 a 2017. A média mensal da temperatura do ar foi 19,48°C e, a precipitação média mensal 145,99 mm. A média para a precipitação anual foi 1.752 mm. Conclui-se, ao se considerar a média dos valores mensais para a temperatura do ar (°C) e precipitação pluviométrica (mm) no período 2010-2017 que, caracteristicamente, no bairro camobi não existe período seco. Porém, ao se observar os resultados ano a ano verifica-se a ocorrência de períodos secos em 2010 para os meses de março e outubro, para 2011 no mês de dezembro, em 2012 para os meses de março e junho, em 2016 para o mês de junho e, em 2017 ocorre período seco no mês de julho. Também se observa que, mesmo nos anos mais secos, caracterizados como anos com presença de estiagem, o período seco acontece em pequenos intervalos como ocorreu, por exemplo, nos anos de 2011, 2012 e 2016.

A new species and first record of Vates Burmeister, 1838 from the Atlantic Rainforest (Mantodea: Vatinae)

A new species of praying mantis, Vates phoenix sp. nov. (Mantidae, Vatinae), is described from localities within Rio de Janeiro and São Paulo states, Brazil. This is the first record of Vates from the Atlantic Rainforest biome. The new species is unique among its congeners in having, among other features, strongly reduced cuticular projections above the lateral ocelli, structures otherwise well developed and produced in all other species of Vates. Remarks on the natural history and biogeography of Vates, in relation to this new finding, are further discussed.

Cercyon Leach, 1817 (Coleoptera: Hydrophilidae: Sphaeridiinae) from Brazil: new species and records

Abstract The study of ca. 280 specimens of Cercyon Leach, 1817 (Hydrophilidae: Sphaeridiinae: Megasternini) deposited in the Colecao Entomologica Pe. J.S. Moure, Universidade Federal do Parana, Brazil, revealed a new species from Atlantic Rain Forest biome in Parana State (Southern Brazil) and new records. Cercyon (Cercyon) curi sp. nov. is herein described and illustrated, belonging to the Neotropical C. variegatus species group. Cercyon (Cercyon) nigriceps (Marsham, 1802) is recorded for the first time in Parana State, and Cercyon (Cercyon) inquinatus Wollaston, 1854 from Amazonas State (Northern Region); these records extend the distributional range of both species in Brazil. Cercyon (Cercyon) praetextatus (Say, 1825) is recorded for the first time from Brazil based on specimens collected in Parana. Those three species were previously recorded as introduced in South America.

Taxonomic study on a collection of terrestrial mollusks from the region of Santa Maria, Rio Grande do Sul state, Brazil

The malacological collection of the Universidade Federal de Santa Maria, curated by Dr. Carla B. Kotzian, has been recently donated to the Museu de Zoologia da Universidade de São Paulo (MZSP, Brazil). The collection is rich in well preserved specimens of terrestrial gastropods from central Rio Grande do Sul state, in southernmost Brazil. That region, centered in the municipality of Santa Maria, represents a transitional area between the Atlantic Rainforest and Pampas biomes and has been scarcely reported in the literature. Therefore, we present a taxonomical study of these specimens, complemented by historical material of the MZSP collection. Overall, we report 20 species, mostly belonging to the Stylommatophora, from which four represent new records for Rio Grande do Sul: Adelopoma brasiliense, Happia vitrina, Macrodontes gargantua, and Cyclodontina corderoi. The present report of C. corderoi is also the first from Brazil. Two introduced species were found in the studied material: Bradybaena similaris and Zonitoides sp.

Diversity of foliicolous lichens in isolated montane rainforests (Brejos) of northeastern Brazil and their biogeography in a neotropical context

AbstractFoliicolous lichenized fungi (FLF) are widely distributed in tropical forests. The Brazilian Atlantic rainforest, one of the most diverse rainforest biomes, has multiple phyto‐physiognomies. Montane forest fragments or forest refuges, so‐called “Brejos,” are located within the semiarid Caatinga in Northeast Brazil. Our objective was to determine the FLF diversity within five Brejos and to analyze their biogeographic affinities within the Neotropics. The FLF biota of the Brejos was compared with that of 21 sites belonging to seven other rainforest biomes, ranging from the Atlantic rainforest in Argentina, to montane rainforests in Ecuador, to the Amazonia basin, and rainforests in Central America. One hundred and fifty‐six species were identified in the Brejos. This biota is most similar to that of the Atlantic rainforest and eastern Amazonia, while that of western Amazonia is more similar to that of the Andes and rainforests in Central America (Chocó). Multiple species identified in the Brejos have a wide distribution in tropical America, and only 11 are potentially endemic. Few other species have also a restricted distribution. The FLF biota of the Chocó and western Amazon is substantially richer than that of eastern Amazon, the Atlantic rainforest and the Brejos. This suggests that the biota of the latter areas is largely a depauperate subset of the Chocó and the western Amazon region. We argue that the major differences between the two large regions are related to the Pleistocene and Pliocene, when paleoclimatic and geological changes caused the isolation of the Brejos and the temporary fragmentation particularly of eastern Amazonia.

Tick infestation on caimans: a casual tick-host association in the Atlantic rainforest biome?

Ticks are parasites of birds, mammals, amphibians, and reptiles, but information about tick communities that parasitize reptiles in the Neotropical region is still fragmentary. In the present study, we assessed the presence of ticks on broad-snouted caimans (Caiman latirostris) and Cuvier's dwarf caimans (Paleosuchus palpebrosus) trapped in the Atlantic rainforest biome in Pernambuco state, north-eastern Brazil, to determine which tick species feed on these animals and how frequent or rare this parasite-wildlife association is. We also report an occasional finding of Amblyomma rotundatum on a smooth-fronted caiman (Paleosuchus trigonatus) in the Amazon biome in Pará state, northern Brazil. Out of 490 animals trapped in the Atlantic rainforest biome, four (0.82%) broad-snouted caimans were infested by ticks. Ticks belonged to two Amblyomma species: A. rotundatum (three females) and A. fuscum (one male). Our findings indicate that ticks are infrequent parasites of caimans in the Atlantic rainforest biome. Tick infestation on broad-snouted caimans is probably of minor clinical significance and probably a casual finding due to habitat sharing with the common tick hosts.

<p><strong>Rock star flowers: <em>Conchocarpus hendrixii </em>(Galipeinae, Rutaceae), a new species from Eastern Brazil with notes on its phylogenetic position in the genus</strong></p>

A new species, Conchocarpus hendrixii (tribe Galipeinae, Rutaceae), is described and illustrated. To date, this new species is known from populations observed in the municipalities of Cardoso Moreira and São Fidélis in Serra da Bandeira/Serra da Vista mountain ranges in northern Rio de Janeiro state in the Atlantic Rainforest biome and was brought to light as an undescribed species thanks to photographs shared on the social media site Facebook. The epithet “hendrixii” is in honor of Jimi Hendrix, guitarist and singer-songwriter, who wrote the song “Purple Haze,” in reference to the purple color of the flowers of the new species. Analyzes showed that flowers of the new species bear a staminal tube, a characteristic present only in C. odoratissimus among the Conchocarpus. However, this species bears flowers with much shorter staminal tubes (c. 2–2.5 mm in length v. 1–1.2 cm in the new species) and smaller flowers, among other morphologically dissimilar characteristics. Molecular phylogenetic analysis using nuclear (ITS-1 and IT-2) and plastidial markers (trnL-trnF and rps16 intron) were conducted and demonstrated that the new species belongs to an internal clade in Conchocarpus, together with species formerly assigned to Almeidea (currently included in Conchocarpus). The presence of pantoporate pollen grains, a synapomorphic trait to this clade supports the molecular results. Conservation status as well as data from foliar and floral (with an emphasis on the staminal tube) anatomy are presented.

Rizogênese <i>in vitro</i> em brotações de <i>Luehea divaricata</i> Mart. & Zucc.

Luehea divaricata, conhecida popularmente como açoita-cavalo, é uma espécie florestal nativa da Mata Atlântica muito utilizada para a recuperação de áreas degradadas. Sua madeira pode ser empregada para as mais diversas finalidades, o que contribuiu para a redução de suas populações naturais e ocasionou dificuldades na obtenção de sementes com qualidade genética, fisiológica e sanitária para uso na produção de mudas. Sendo assim, a micropropagação é uma alternativa para a produção de mudas da espécie para uso em projetos ambientais. Com isso, o presente trabalho teve como objetivo otimizar o processo de rizogênese in vitro e, para isso, foram avaliadas, inicialmente, diferentes concentrações de sais do meio nutritivo WPM. Em seguida, foram estudados os efeitos do ácido indolbutírico (AIB), adicionado ao meio em tratamento “pulse” por 15 dias, e do ácido naftalenoacético (ANA), na rizogênese, em ambos os casos em cultivo em meio WPM cuja concentração de sais foi reduzida à metade (WPM/2). Por fim, também foi analisado o efeito da combinação de volumes de vermiculita com WPM/2. Os resultados indicaram que o meio WPM/2 apresentou resultados promissores para o estabelecimento (98%) in vitro e, no que diz respeito à formação de raízes adventícias primárias, após 45 dias de cultivo in vitro observaram-se as maiores médias (40,52%), independentemente da concentração de sais do meio. O tratamento “pulse” após 30 dias de cultivo in vitro, independentemente da concentração de AIB, resultou em uma média de 25,18% de formação de raízes adventícias primárias. As combinações de 20 mL + 15 cm³, 20 mL + 30 cm³ e 30 mL + 30 cm³ de meio nutritivo e de vermiculita, respectivamente, foram as mais favoráveis para a formação de raízes adventícias laterais de segunda ordem, proporcionando médias entre 38 e 49,5% após 45 dias de cultivo in vitro. Para otimizar o processo de rizogênese de Luehea divaricata é indicado o cultivo in vitro por 45 dias em meio nutritivo WPM/2, combinado com vermiculita, prescindindo da adição de auxinas.

Phytosociology of stratification in a lowland tropical rainforest occurring north of the Tropic of Cancer in Meghalaya, India

Stratification in lowland rainforests of Meghalaya, India, which represent the westernmost limit of the rainforests north of the Tropic of Cancer, was studied in horizontal and vertical planes to elucidate the patterns in stacking of species diversity and community attributes, and to draw comparisons with rainforests of ‘Indo-Malaya’ ecozone (biogeographical realm). All individuals ≥10 cm GBH (girth at breast height) were enumerated in six transects of 10 m width and up to 500 m length covering 2.45 ha area. The stratification of whole assemblage of species in vertical plane is referred to as ‘storey structure’ (=height class distribution), which explains structural complexity. In horizontal plane, it is typically referred to as ‘stand structure’ (=girth class distribution), which explains structural heterogeneity. The stratification of an individual species in vertical plane is referred to as ‘loftiness’ and in horizontal plane, it is frequently referred to as ‘population structure’. The stand structure was characterized by a negative exponential relationship or a reverse J-shaped curve, which is typical of a well regenerating forest stand. The storey structure was characterized by the low stature of the rainforest (<30 m), subtle layering in the canopy with dearth of discrete multi-stories, narrower widths of the stories and a thick understory. The cluster analysis and ‘candlestick charts’ showed that the dominant species spatially segregated in canopy height to profile three strata, viz., an understory of juveniles and shrubs below 5 m, a middle-storey of intermediate trees between 5 and 15 m, and an overstory of large trees between 15 and 25 m. Emergent trees of a few species may reach up to 30 m. The individuals tended to scatter in increasingly wider range of height classes from a lower to the next higher girth class, creating a ‘torchlight scatter’ pattern, with a tendency to concentrate towards smaller height classes due to stochastic factors, which potentially influence vertical growth proportionate to diametric growth. In comparison to equatorial rainforests of Malaysia and seasonal rainforests of southwestern China, the rainforests of Meghalaya are short-statured at the geographic extremity of the occurrence of rainforest biome in Asia–Pacific region, owing to floristic composition, site quality factors, excessively higher quantities of rainfall and high differential of precipitation and potential evapotranspiration. Despite limited diversity of megaphanerophytes, these rainforests deserve concerted conservation efforts as they stack high diversity of meso-, micro- and nano-phanerophytes.

A new species of Amblyomma (Acari: Ixodidae) associated with monkeys and passerines of the Atlantic rainforest biome, Southeastern Brazil

Recent studies have reported several larvae of an unidentified Amblyomma species on passerine birds in Atlantic rainforest fragments in southeastern Brazil. These larvae yielded a unique 16S rRNA haplotype designated as Amblyomma sp. haplotype Nazaré, which showed nucleotide identity levels of 91% to Amblyomma parkeri Fonseca & Aragão, 1952 and 88% to Amblyomma longirostre (Koch, 1844). Herein, we describe Amblyomma sp. haplotype Nazaré as a new species, Amblyomma romarioi n. sp. Martins, Luz & Labruna, through a formal description of the male and female adult stages. Amblyomma romarioi is morphologically and genetically most closely related to A. parkeri, A. longirostre and Amblyomma geayi Neumann, 1899. Among males, the rectangular basis capituli and rounded coxa I spurs separates A. romarioi from A. parkeri, A. longirostre, and A. geayi, which have basis capituli triangular or slightly hexagonal, and pointed coxa I spurs. Among females, the V-shaped genital aperture and coxa I rounded spurs of A. romarioi contrasts to the U-shaped genital aperture and coxa I pointed spurs in A. parkeri, A. longirostre, and A. geayi. Larvae of A. romarioi have been collected on 24 species of passerines. The few records of nymphs and adults were on the black-fronted titi monkey Callicebus nigrifrons (Spix, 1823). The current distribution of A. romarioi is restricted to the Brazilian Atlantic rainforest, southeastern Brazil, in areas with altitude between 363 and 1600 m, within the distribution of C. nigrifrons. We discuss ecological features of Amblyomma romarioi, comparatively to A. parkeri, A. longirostre and A. geayi. The present study increases the Brazilian tick fauna to 74 species.

Serologic and molecular survey of Rickettsia spp. in dogs, horses and ticks from the Atlantic rainforest of the state of Bahia, Brazil.

Tick-borne spotted fever in Brazil is known to be caused by two agents, Rickettsia rickettsii and Rickettsia parkeri. Nothing was known about these agents in one area of the Atlantic rainforest biome of Bahia state, where during March to June 2016, 356 rural dogs and 69 horses were sampled and their sera were processed through indirect immunofluorescence assay against antigens of R. rickettsii, R. parkeri, Rickettsia amblyommatis and Rickettsia bellii. Ticks collected from these dogs and horses were molecularly tested for the presence of rickettsial DNA. Overall, 16.4% (58/356) dogs and 24.6% (17/69) horses were seroreactive to Rickettsia spp. Five tick species, Rhipicephalus sanguineus sensu lato (s.l.), Amblyomma ovale, A. sculptum, R. microplus, and A. naponense, were collected from dogs, whereas horses were infested by A. sculptum and Dermacentor nitens. A total of 242 ticks from dogs and 62 from horses were analyzed by PCR targeting rickettsiae, which were detected in only 4/27 (14.8%) A. ovale. Fragments of the rickettsial gltA and ompA genes from these four ticks were 100% identical to theAtlantic rainforest strain of R. parkeri. The presence of A. ovale on dogs was positively associated with local canine seroreactivity to R. parkeri. Our results provide evidence for the transmission of R. parkeri strain Atlantic rainforest from A. ovale to domestic dogs within the rural area of Ilhéus, similarly to other areas of the Atlantic rainforest biome of Brazil, where human cases of R. parkeri-caused spotted fever have been reported.

Description of a new Brazilian species of Mycodrosophila (Diptera, Drosophilidae) with emphasis on the morphology of phallic sclerites

Mycodrosophila is a cosmopolitan genus of Drosophilidae that comprises approximately 130 species with mycophagous habitats. In this study, we described a new species of Mycodrosophila based on morphological traits and included details of the male terminalia. The holotype is from Eugênio Lefévre, locality in Campos do Jordão municipality, SP, Brazil, located in the Atlantic rainforest biome and was sampled in the 1930s.

Characterizing the Fluxes and Age Distribution of Soil Water, Plant Water, and Deep Percolation in a Model Tropical Ecosystem

AbstractRecent field observations indicate that in many forest ecosystems, plants use water that may be isotopically distinct from soil water that ultimately contributes to streamflow. Such an assertion has been met with varied reactions. Of the outstanding questions, we examine whether ecohydrological separation of water between trees and streams results from a separation in time, or in space. Here we present results from a 9‐month drought and rewetting experiment at the 26,700‐m3mesocosm, Biosphere 2‐Tropical Rainforest biome. We test the null hypothesis that transpiration and groundwater recharge water are sampled from the same soil volume without preference for old nor young water. After a 10‐week drought, we added 66 mm of labeled rainfall with 152‰ δ2H distributed over four events, followed by background rainfall (−60‰ δ2H) distributed over 13 events. Our results show that mean transit times through groundwater recharge and plant transpiration were markedly different: groundwater recharge was 2–7 times faster (~9 days) than transpired water (range 17–62 days). The “age” of transpired water showed strong dependence on species and was linked to the difference between midday leaf water potential and soil matric potential. Moreover, our results show that trees used soil water (89% ±6) and not the “more mobile” (represented by “zero tension” seepage) water (11% ±6). The finding, which rejects our null hypothesis, is novel in that this partitioning is established based on soil water residence times. Our study quantifies mean transit times for transpiration and seepage flows under dynamic conditions.

Nutrient cycling from leaf litter in multistrata successional agroforestry systems and natural regeneration at Brazilian Atlantic Rainforest Biome

The conversion of forests to agricultural crops impacts these ecosystems, causing negative changes in the biological, physical and chemical soil attributes. Agroforestry systems (AFs) represent an environmental sustainable alternative that can bind healthy food production and nature conservation. Litter production and decomposition are key roles to carbon and nutrient cycles in the tropics, as the main sources of nutrients for plant growing. The aim of this study was to quantify the amount of leaf litter accumulated aboveground and its contribution to nutrient return through decomposition process in 5- and 10-year multistrata successional agroforestry systems (AF5 and AF10) as compared to 10-year natural regeneration areas (NR10) at Brazilian Atlantic Rainforest Biome. Greater amounts of standing litter were observed on AF5 (61 Mg ha−1) as compared to AF10 (45 Mg ha−1) and NR10 (39 Mg ha−1), with leaf contribution of 17% (AF5), 25% (NR10) and 30% (AF10). Leaf decomposition was performed using litterbags, and all curves were fitted to a double exponential model for remaining mass, C and Mg and to a single exponential model for N, P, K and Ca. The half-time life of decomposing leaves varied from 173 days (NR10) to 289 (AF5) and 301 days (AF10), and the half-time mineralization of nutrients varied from 15 (N on AF5) to 257 days (K on AF10). Despite their low contribution on total standing litter, leaf fraction is able to return at least 100 kg ha−1 N, 5 kg ha−1 P and 10 kg ha−1 K to soil of multistrata agroforestry systems, reducing NPK external inputs dependence to small farmers.

Wild Brazilian species of Eugenia genera (Myrtaceae) as an innovation hotspot for food and pharmacological purposes.

The Myrtaceae is one of the most common plant families in Brazil, including >1000 species of native fruit spread from North to South, where around 50% of all species are endemic to the Atlantic Rain Forest Biome. Most Brazilian species belong to Eugenia, Campomanesia, Psidium and Myrciaria genera. In general, they are characterized by the presence of leaves opposite, simple, entire, with pellucid glands containing ethereal oils and produces berry-like, fleshy fruits with a wide diversity of beneficial characteristics. Several parts of these plants are widely used in regional folk medicine as an astringent, anti-inflammatory, antihypertensive, to treat gastrointestinal disorders, and so on. Some species have already been studied and most of their metabolic effects are attributed to the presence of polyphenols, carotenoids as well as sesquiterpenes and monoterpenes. In addition, the Myrtaceae family has great economic potential, because of the sensory characteristics which encourages their commercial exploitation plus the presence of phytochemicals which play an important role in managing several degenerative chronic diseases besides representing a hotspot of technological innovation for food, cosmetic and pharmaceutical purposes. In this context, this review discusses about the importance of some Eugenia genera representatives such as Eugenia uniflora, Eugenia stipitata, Eugenia brasiliensis, Eugenia pyriformis and Eugenia dysenterica, emphasizing its profile of bioactive compounds as well as the knowledge of the nutritional and functional fruit potential, providing information for further studies aiming to stimulate the cultivation of Brazilian wild berries, for consumption and new food ingredients.