Detecting ontogenetic stages of the palm Attalea humilis in fragments of the Brazilian Atlantic forest

2000 ◽  
Vol 78 (9) ◽  
pp. 1227-1237 ◽  
Author(s):  
Alexandre F Souza ◽  
Fernando R Martins ◽  
Dalva M Silva Matos

A study of the ontogenetic stages of the acaulescent palm Attalea humilis Mart. ex. Spreng was conducted in three fragments (1.6, 6.4, and 9.9 ha) of the Atlantic forest in southeastern Brazil. The fragments were damaged by fire during the study period (1996-1999). External macromorphology and quantitative measures of leaf number and length of the newest leaf's rachis allowed the distinction of five ontogenetic stages. Seedlings were attached to buried fruit remains and presented entire leaves. Juveniles possessed incomplete segmentation of the blade. Pinnatifid-leafed, non-reproducing individuals were morphometrically divided in two groups: immature, with fewer leaves and smaller but highly variable youngest leaf length, and virginile, with more and larger leaves, but more constant youngest leaf length; the critical crown size by which immature and virginile stages could be identified varied according to fragment and year. Reproductive palms bore identifiable reproductive structures. Seedlings, juveniles, and immatures had fewer leaves than virginile and reproductive individuals. Leaf length was similar between seedlings and juveniles but increased in later stages. The characteristics of each stage were fairly constant throughout the study years in the three fragments and were little affected by fire, indicating that the stages we define in this study are important in the developmental program of A. humilis.Key words: stage-structured populations, ontogenetic stages, forest fragments, fire, leaf size, leaf number.

2003 ◽  
Vol 81 (2) ◽  
pp. 101-112 ◽  
Author(s):  
Alexandre F Souza ◽  
Fernando R Martins ◽  
Luis Carlos Bernacci

We investigated the patterns of growth and reproduction of the understory clonal palm Geonoma brevispatha based on the identification of post-germinative ontogenetic stages, over a 3-year period. Genets were monitored in 100 5 × 5 m plots and 100 2 × 2 m subplots, in a 1-ha area of swamp forest in São Paulo state, southeastern Brazil. Ramets pass through four ontogenetic stages (bifid-leafed juveniles, pinnatifid-leafed stemless immatures, stemmed nonreproductive virgins, and reproducers). Leaf size, leaf number, and leaf production rate increased during ontogeny, but diameter growth rate was higher among immatures. Stem length, number of nodes, and leaf rachis length were positively correlated across ontogenetic stages, but crown height was smaller than stem length in adult palms because of frequent leaning. Leaf number and sexual fecundity increased with ramet size, but declined in larger, senescent ramets. Clonal fecundity preceded sexual fecundity, and sexual and clonal fecundity increased continuously with genet size. No relationship was found between sexual and clonal fecundity. Growth and survival strategies of G. brevispatha were consistent with the patterns found in other tropical clonal palm species. Sexual fecundity and cloning seem to be two integrated processes favored by environmental conditions that also support the growth of existing ramets.Key words: stage-structured populations, ontogenetic stages, swamp forest, Brazil, Atlantic forest, senescence.


2003 ◽  
Vol 17 (6) ◽  
pp. 1827-1839 ◽  
Author(s):  
RÔMULO RIBON ◽  
JOSÉ EDUARDO SIMON ◽  
GERALDO THEODORO DE MATTOS

2020 ◽  
Vol 11 (7) ◽  
pp. 1-15
Author(s):  
Fernado Silva Coutinho ◽  
Luiz Alberto da Silva Rodrigues Pinto ◽  
Marcos Gervasio Pereira ◽  
Shirlei Almeida Assunção ◽  
Silver Rodrigues Zandoná ◽  
...  

The southeast region of Brazil, in the Atlantic Forest biome, has been impacted for a long time, observing today small agricultural areas inserted in a matrix of pastures and forest fragments, the soils being highly modified due to the different forms of use they were submitted. The objective of this study was to evaluate the organic carbon content in the humic fractions on soil organic matter (SOM), the distribution of aggregates in size classes and the porosity and aggregates density variables by means of computed tomography in secondary forest, pasture and agriculture areas in Pinheiral (RJ). Three areas composed of secondary forests with different succession stages and three managed areas were evaluated: Secondary Forest (SF) Initial Stage (SFIS), Medium Stage (SFMS), Advanced Stage (SFAS), mixed managed pasture (MMP), and perennial and annual agriculture (PA and AA, respectively). Three types of samples were collected in different layers: i) deformed samples to quantify carbon in the SOM humic fractions; ii) clods for quantifying the mass of aggregates and later assessing the distribution by diameter classes; and iii) undisturbed samples collected with the aid of an acrylic cylinder to perform computed tomography (CT). Humic substances and aggregate classes below 2.0 mm were the attributes most influenced by the forms of use and/or vegetation cover. The CT technique proved to be efficient in the measurement of the edaphic attribute’s porosity and density of the aggregates, helping in the characterization and separation of the different environments.


2018 ◽  
Vol 18 (2) ◽  
Author(s):  
Alex Augusto de Abreu Bovo ◽  
Marcelo Magioli ◽  
Alexandre Reis Percequillo ◽  
Cecilia Kruszynski ◽  
Vinicius Alberici ◽  
...  

Abstract: Human-modified landscapes (HMLs) are composed by small, isolated and defaunated forest fragments, which are surrounded by agricultural and urban areas. Information on species that thrives in these HMLs is essential to direct conservation strategies in local and regional scales. Since HMLs are dominant in the Atlantic Forest, we aimed to assess the mammalian diversity in a HML in southeastern Brazil and to propose conservation strategies. We collected data of terrestrial (small-, medium- and large-sized) and volant mammals in three small forest fragments (10, 14 and 26 ha) and adjacent areas, between 2003 and 2016, using complementary methods: active search, camera trapping, live-traps, mist nets and occasional records (i.e., roadkills). In addition, we used secondary data to complement our species list. We recorded 35 native mammal species (6 small-sized, 16 medium- and large-sized, and 13 bats) and seven exotic species in the HML. The recorded mammal assemblage (non-volant and volant), although mainly composed of common and generalist species, includes three medium- and large-sized species nationally threatened (Leopardus guttulus, Puma concolor and Puma yagouaroundi) and two data deficient species (Galictis cuja and Histiotus velatus), highlighting the importance of this HML for the maintenance and conservation of mammal populations. Despite highly impacted by anthropogenic disturbances, the study area harbors a significant richness of medium- and large-sized mammals, being an important biodiversity refuge in the region. However, this biodiversity is threatened by the low quality of the habitats, roadkills and abundant populations of domestic cats and dogs. Therefore, we stress the need of conservation strategies focusing on the medium- and large-sized mammals as an umbrella group, which could benefit all biodiversity in the landscape. We recommend actions that promotes biological restoration, aiming to increase structural composition and connectivity of the forest fragments, reducing roadkills and controlling the domestic cats and dogs' populations, in order to maintain and improve the diversity of mammals in long-term.


2015 ◽  
Vol 3 ◽  
pp. e4404 ◽  
Author(s):  
Roberto Leonan Novaes ◽  
Daniel Rosa ◽  
Davor Vrcibradic ◽  
Leonardo Avilla

Check List ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 1830 ◽  
Author(s):  
Kassius Klay Santos ◽  
Gabrielle Soares Muniz Pacheco ◽  
Marcelo Passamani

Information about the occurrence of medium-sized and large mammals in the Cerrado and the Atlantic Forest is essential for monitoring the conservation status of these species in such biodiversity hotspots. This study presents the results of a survey of medium-sized and large mammals from Quedas do Rio Bonito Ecological Park, located in an ecotone between Cerrado and Atlantic Forest in Southeastern Brazil. Four sampling methods were used: sand plots, camera traps, line transects and tomahawk traps. We recorded 20 species belonging to 12 families and 7 orders, with a high occurrence of Carnivora (50%). We highlight the occurrence of five endangered species: Chrysocyon brachyurus, Leopardus pardalis, L. guttulus, Puma yagouaroundi and P. concolor. The species with the highest frequencies of occurrence were P. concolor (27%), C. brachyurus (17%), and Sylvilagus brasiliensis (13%). Our results confirm that, despite their small size, forest fragments are essential for “top-of-the-chain” species conservation in the region.


2000 ◽  
Vol 78 (9) ◽  
pp. 1227-1237 ◽  
Author(s):  
Alexandre F. Souza ◽  
Fernando R. Martins ◽  
Dalva M Silva Matos

2021 ◽  
Vol 111 ◽  
Author(s):  
Felipe S. Machado ◽  
Aloysio S. Moura ◽  
Ravi F. Mariano ◽  
Rubens Manoel dos Santos ◽  
Paulo O. Garcia ◽  
...  

ABSTRACT Exploratory human activities have resulted in small fragments inserted into a matrix which is inhospitable to small non-flying mammals. The effects of landscape changes alter the distribution patterns of species. Landscape fragmentation patterns for small mammals are controversial, especially considering small fragments and ecotonal regions. Based on these arguments, we investigated the diversity patterns of small mammals in small fragments in the ecotonal Cerrado/Atlantic Forest region. A total of 24 fragments (<40 ha) were studied using tomahawk, sherman and pitfall traps. We found low species richness (11 species, six marsupials and five rodents), which was not expected because it is an ecotonal region. It was verified that composition and community structure are simplified by the marked presence of generalist species and with the increase of species turnover. The small forest fragments present a microhabitat structure with lianas and streams as main environmental filters of groups with ecological similarities. Our findings suggest that these fragments must be managed in order to conserve the local biodiversity and maintain the needed characteristics to enable the occurrence of different ecological groups.


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