scholarly journals Fenologia de Blechnum acutum (Desv.) Mett. (Blechnaceae) em Floresta Atlântica Subtropical (Phenology of Blechnum acutum (Desv.) Mett. (Blechnaceae) in Atlantic Subtropical Forest)

2016 ◽  
Vol 9 (6) ◽  
pp. 1644 ◽  
Author(s):  
Thábia Ottília Hofstetter Padoin ◽  
Andressa Müller ◽  
Jairo Lizandro Schmitt

O clima de uma área é um dos fatores determinantes da dinâmica da vegetação e a fenologia estuda a ocorrência dos eventos vegetativos e reprodutivos das plantas desencadeados principalmente pela precipitação, temperatura e fotoperíodo. Os estudos fenológicos com samambaias, no mundo, aumentaram nas últimas décadas, porém os seus resultados são geralmente descritivos e restritos a poucos locais e a poucas espécies. Foram determinados o padrão e a sazonalidade das fenofases de Blechnum acutum, em Floresta Atlântica subtropical, relacionando-as com os fatores climáticos, a partir do monitoramento de 20 indivíduos, durante 18 meses. Para verificar a sazonalidade das fenofases foi utilizada a estatística circular. Blechnum acutum apresentou maior intensidade da renovação foliar em janeiro (38%), com maior período de atividade entre janeiro e abril de 2014. A formação de esporângios foi a fenofase que demonstrou o padrão sazonal mais evidente e ocorreu com maior intensidade e atividade em outubro de 2014 (25%). A senescência foliar manifestou maior intensidade em fevereiro de 2014 (23%), com 80% dos indivíduos encontrando-se nesta fenofase, em março de 2015. Os padrões fenológicos não demonstraram a mesma continuidade e regularidade em decorrência principalmente da falta de homogeneidade na manifestação da renovação e senescência das folhas pelos indivíduos na população. Os ritmos fenológicos de B. acutum também não foram igualmente influenciados pelas variáveis ambientais analisadas, sendo que a renovação foliar foi a única fenofase relacionada com temperatura e fotoperíodo.     A B S T R A C T The climate of an area is one of the determining factors of the vegetation’s dynamics and phenology studies. The occurrence of vegetative and reproductive events of plants mainly triggered by rainfall, temperature and photoperiod. The phenological studies with ferns in the world have increased in recent decades, but the results are usually descriptive and restricted to few places and few species. It was determined the pattern and seasonality of phenophases of Blechnum acutum in subtropical Atlantic Forest, relating them to the climatic factors, from monitoring 20 individuals for 18 months. To check the seasonality of phenophases the circular statistics were used. Blechnum acutum showed greater intensity of foliar renovation in January (38%), with higher activity period between January and April 2014. The sporangia formation was the phenophase that showed the most obvious seasonal pattern and was more intense and activity in October 2014 (25%). The leaf senescence showed greater intensity in February 2014 (23%), with 80% of individuals meeting in this phenophase in March 2015. The phenological patterns did not show the same continuity and regularity mainly due to the lack of homogeneity in the manifestation renewal and senescence of leaves by individuals in the population. The phenological rhythms of B. acutum were not also influenced by environmental variables, and the leaf renewal was the only phenophase related to temperature and photoperiod. Keywords: climate, photoperiod, sazonality, phenophase, fern.[1]                                                            

2019 ◽  
Vol 46 (7) ◽  
pp. 566 ◽  
Author(s):  
Juliane Pereira-Ribeiro ◽  
Atilla Colombo Ferreguetti ◽  
Helena Godoy Bergallo ◽  
Carlos Frederico Duarte Rocha

Abstract ContextAnimal activity patterns throughout the day constitute an important dimension of their ecological niche, and may have ecological and evolutionary implications; for an organism to be active during the day or night period, a series of conditions requiring different anatomical, physiological and behavioural adaptations must be met. AimsTo study the anuran community in an area of Atlantic Forest in Brazil, to evaluate the species activity period as well as the diurnal and nocturnal detection probabilities of anurans, and to relate these activities to environmental variables such as air temperature, relative humidity and precipitation. MethodsThe anurans were sampled along 21 plot transects in the diurnal period and during a nocturnal period, with temperature and relative humidity measured in each plot. Species were considered predominantly diurnal or nocturnal if 35% or more individuals were recorded during one of these periods. Anuran detectability was estimated using single-season occupancy models, relating to environmental variables. Key resultsOf the individuals recorded, 12% were recorded during diurnal sampling and 88% were recorded during nocturnal sampling, with Ololygon agilis being the only species considered diurnal. The probability of detection was affected by only two variables (period and humidity). ConclusionsThe anuran community in the study area was essentially nocturnal, with only one species that could be considered diurnal. Additionally, detectability was higher at night, with humidity being the most important variable affecting species detection. ImplicationsSurveys can be planned under climatic conditions that positively influence the probabilities of detection to improve the effectiveness of monitoring species and/or anurans community.


Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 775
Author(s):  
Carlos Esse ◽  
Francisco Correa-Araneda ◽  
Cristian Acuña ◽  
Rodrigo Santander-Massa ◽  
Patricio De Los Ríos-Escalante ◽  
...  

Pilgerodendron uviferum (D. Don) Florin is an endemic, threatened conifer that grows in South America. In the sub-Antarctic territory, one of the most isolated places in the world, some forest patches remain untouched since the last glaciation. In this study, we analyze the tree structure and tree diversity and characterize the environmental conditions where P. uviferum-dominated stands develop within the Magellanic islands in Kawésqar National Park, Chile. An environmental matrix using the databases WorldClim and SoilGrids and local topography variables was used to identify the main environmental variables that explain the P. uviferum-dominated stands. PCA was used to reduce the environmental variables, and PERMANOVA and nMDS were used to evaluate differences among forest communities. The results show that two forest communities are present within the Magellanic islands. Both forest communities share the fact that they can persist over time due to the high water table that limits the competitive effect from other tree species less tolerant to high soil water table and organic matter. Our results contribute to knowledge of the species’ environmental preference and design conservation programs.


Mammalia ◽  
2019 ◽  
Vol 83 (4) ◽  
pp. 363-371 ◽  
Author(s):  
Atilla C. Ferreguetti ◽  
Walfrido M. Tomas ◽  
Helena G. Bergallo

Abstract The spotted paca Cuniculus paca (Linnaeus, 1766) is a medium-sized caviomorph rodent of the Cuniculidae family that mainly inhabits tropical forests, but may occur in other habitat types, often associated with water bodies. We aimed to verify which factors influence the spatial and temporal distribution of C. paca in the Vale Natural Reserve (VNR), Espírito Santo, Brazil. We used 39 camera traps to model occupancy and detectability and to estimate the species activity period. The spotted paca showed high occupancy at low distances from water resources and high densities of palm species. The species avoided areas with high poaching intensity, and activity frequency was reduced by extreme temperature and by a higher intensity of poaching. We conclude that in the VNR, the C. paca is a nocturnal species and that it is necessary to assess other elements that could potentially affect the spatial and temporal distribution of the spotted paca in the Atlantic Forest.


Check List ◽  
2011 ◽  
Vol 7 (6) ◽  
pp. 841 ◽  
Author(s):  
Marcoandre Savaris ◽  
Silvana Lampert ◽  
Elaine Maria Lucas ◽  
Angelo Vinicius da Rosa Peres ◽  
Juliana Orsato ◽  
...  

The Atlantic Forest Biome is among the world’s hotspots for biodiversity conservation and concentrates the greatest diversity of amphibians in the world. However, information on the distribution pattern of species is largely unknown in this biome. This study report new records of Vitreorana uranoscopa for northeast region of Rio Grande do Sul.


2018 ◽  
Vol 27 (2) ◽  
pp. 163-171
Author(s):  
Ana Catia Santos da Silva ◽  
Lorena Andrade Nunes ◽  
Wanessa de Lima Batista ◽  
Marcos Gonçalves Lhano

The objective of the present study was to examine variation in the shape and size of pronotum, hind femur, and head in the males of Orphulellapunctata (De Geer, 1773) from three different Brazilian biomes: the Cerrado, the Atlantic Forest, and the Pantanal. A total of 150 specimens were analyzed from three populations. The results of MANOVA indicated significant differences (p<0.01) in the shape of the analyzed structures of O.punctata from the different biomes. The results of ANOVA demonstrated significant differences (p<0.05) in the size of all analyzed structures. Pearson’s correlation analyses among the different structures and the environmental variables revealed that the shape of pronotum, hind femur, and head (dorsal view), as well as the size of pronotum and head (dorsal and lateral views) varied with the geographic longitude, while the shape of hind femur and head (dorsal view) showed a significant negative correlation with size. Results indicated that the shape and size of the analyzed structures, in general, were influenced by the geographical variables.


2009 ◽  
Vol 6 (4) ◽  
pp. 6601-6634 ◽  
Author(s):  
B. Bjarnadottir ◽  
B. D. Sigurdsson ◽  
A. Lindroth

Abstract. This study reports 3-year measurements (2004–2006) of net ecosystem exchange (NEE) over a 12–14 year old Siberian larch forest in Iceland established on previously grazed heath land pasture that had been site-prepared prior to planting. The study evaluated interannual and seasonal variation of NEE and its component fluxes, gross primary production (GPP) and ecosystem respiration (Re), with the aim to clarify how climatic factors controlled the site's carbon balance. The young plantation acted as a relatively strong sink for CO2 during all of the three years, with a net sequestration of −375, −566 and −245 g CO2 m−2 for years 2004, 2005 and 2006, respectively. The annual carbon balance was strongly influenced by climatic factors leading to a high inter-annual variability in NEE. This variation was more related to variation in carbon efflux (Re) than carbon uptake (GPP). The abiotic factors that showed the strongest correlation to Re were air temperature during the growing season and soil water potential. The GPP mostly followed the seasonal pattern in irradiance, except in 2005, when the plantation experienced severe spring frost damage that set the GPP back to zero. It was not expected that the rather slow-growing Siberian larch plantation would be such a strong sink for atmospheric CO2 only twelve years after site preparation and afforestation.


2020 ◽  
Vol 8 ◽  
Author(s):  
Ana Munévar ◽  
Pedro Cardoso ◽  
Yolanda Piñanez Espejo ◽  
Gustavo Andres Zurita

The semideciduous Atlantic Forest is one of the most diverse ecosystems in the world with a great diversity of spiders. Most spider-related studies in this ecosystem focused on species richness and composition; however, little is known about their trait diversity (including morphological, ecological and/or physiological traits). Two main datasets were compiled to generate a complete record of spider traits for this ecosystem. Here, we present two datasets about 259 species of spiders from the semideciduous Atlantic Forest of Argentina. The trait data set compiled information of morphological and ecological traits such as body size, femur length, ocular distance, foraging strategy, prey range, circadian activity and stratum preference; traits were assessed by species considering sexual dimorphism. The second dataset included information about phenology (season when spiders were collected), number of individuals assessed by species and presence/absence of spiders in the different sample sites. This dataset has high potential to help researchers in recording the state of a component of biodiversity (functional) and contributes with the study of ecosystem services and species conservation.


Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2088
Author(s):  
Federico Ossi ◽  
Nathan Ranc ◽  
Paul Moorcroft ◽  
Priscilla Bonanni ◽  
Francesca Cagnacci

Winter supplemental feeding of ungulates potentially alters their use of resources and ecological interactions, yet relatively little is known about the patterns of feeding sites use by target populations. We used camera traps to continuously monitor winter and spring feeding site use in a roe deer population living in a peri-urban area in Northern Italy. We combined circular statistics with generalized additive and linear mixed models to analyze the diel and seasonal pattern of roe deer visits to feeding sites, and the behavioral drivers influencing visit duration. Roe deer visits peaked at dawn and dusk, and decreased from winter to spring when vegetation regrows and temperature increases. Roe deer mostly visited feeding sites solitarily; when this was not the case, they stayed longer at the site, especially when conspecifics were eating, but maintained a bimodal diel pattern of visits. These results support an opportunistic use of feeding sites, following seasonal cycles and the roe deer circadian clock. Yet, the attractiveness of these artificial resources has the potential to alter intra-specific relationships, as competition for their use induces gatherings and may extend the contact time between individuals, with potential behavioral and epidemiological consequences.


2017 ◽  
Vol 107 (5) ◽  
pp. 634-644 ◽  
Author(s):  
R.D. Coutinho-Silva ◽  
M.A. Montes ◽  
G.F. Oliveira ◽  
F.G. de Carvalho-Neto ◽  
C. Rohde ◽  
...  

AbstractSeasonality is an important aspect associated with population dynamic and structure of tropical insect assemblages. This study evaluated the effects of seasonality on abundance, richness, diversity and composition of an insect group, drosophilids, including species native to the Neotropical region and exotic ones. Three preserved fragments of the northern Atlantic Forest were surveyed, where temperatures are above 20 °C throughout the year and rainfall regimes define two seasons (dry and rainy). As opposed to other studies about arthropods in tropical regions, we observed that abundance of drosophilids was significantly higher in the dry season, possibly due to biological aspects and the colonization strategy adopted by the exotic species in these environments. Contrarily to abundance, we did not observe a seasonal pattern for richness. As for other parts of the Atlantic Forest, the most representative Neotropical species (Drosophila willistoni, D. sturtevanti, D. paulistorum and D. prosaltans) were significantly more abundant in the rainy season. Among the most abundant exotic species, D. malerkotliana, Zaprionus indianus and Scaptodrosophila latifasciaeformis were more importantly represented the dry season, while D. simulans was more abundant in the rainy period. The seasonality patterns exhibited by the most abundant species were compared to findings published in other studies. Our results indicate that exotic species were significantly more abundant in the dry season, while native ones exhibited an opposite pattern.


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