Consulta: subjectFacets:"Environmental heterogeneity"
Registros recuperados: 8
Data/hora: 06/06/2024 13:02:32

Spatial relationships between Ananas ananassoides (Bromeliaceae) and Tachigali vulgaris (Fabaceae) influencing the structure of the Amazon/Cerrado transition in Brazil
Provedor de dados: 67
Autores: Elias,Fernando; Teixeira,Nayara D. A; Marimon Junior,Ben Hur.
In the present study, we tested the hypothesis that: a) bromeliad Ananas ananassoides individuals and Tachigali vulgaris tree individual have an aggregate distribution pattern, and b) are spatially dissociated. To this effect, we quantified all A. ananassoides and T. vulgaris individuals (DBH of at least 30 cm) in large plot (1 ha) composed by 100 subplots measuring 10×10 m in a savanna woodland in the Bacaba Municipal Park, Nova Xavantina, Mato Grosso. The spatial pattern of A. ananassoides and T. vulgaris, and their spatial relationships, were measured using the aggregation and the association index, respectively. Both species had an aggregate distribution pattern and were spatially dissociated, which corroborates the hypotheses of this study. In this...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Interspecific competition; Spatial dynamics; Gaps; Environmental heterogeneity; Competição interespecífica; Dinâmica espacial; Clareiras; Heterogeneidade ambiental.
Ano: 2017
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2017000300010

Ecologie larvaire de l'huître perlière (Pinctada margaritifera, L.), croissance et dispersion dans un lagon d'atoll polynésien
Provedor de dados: 5
Autores: Thomas, Yoann.
Understanding key factors determining the bentho-pelagic species larval growth and dispersal remains one of the challenges of marine ecology, notably to understand the adult population structure and dynamics. In the present study, we explore this determinism on the development and dispersal of the black-lip pearl oyster (Pinctada margaritifera var. cumingii, Linné 1758) larvae in a French Polynesian atoll lagoon (Ahe, Tuamotu archipelago). Rearing of the pearl oyster for the production of black pearls takes on a major social and economic place in French Polynesia. However, the supply of pearl oyster seed to the farms depends entirely on the natural collection of wild spat of the only one specie P. margaritifera, and spatial and temporal variability of spat...
Tipo: Text
Palavras-chave: Ecologie larvaire; Hétérogénéité environnementale; Modélisation; Croissance; Dispersion; Huître perlière à lèvres noires; Pinctada margaritifera; Lagon d’atoll; Polynésie française; Larval ecology; Environmental heterogeneity; Modeling; Growth; Dispersal; Black-lip pearl oyster; Pinctada margaritifera; Atoll lagoon; French Polynesia.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00003/11449/7999.pdf

Density-dependent growth of bivalves dominating the intertidal zone of Banc d'Arguin, Mauritania: importance of feeding mode, habitat and season
Provedor de dados: 5
Autores: Van Der Geest, Matthijs; Van Der Lely, Jorge A. C.; Van Gils, Jan A.; Piersma, Theunis; Lok, Tamar.
Accurate predictions of population dynamics require an understanding of the ways by which environmental conditions and species-specific traits affect the magnitude of density dependence. Here, we evaluated the potential impact of season and habitat (characterized by sediment grain size and seagrass biomass) on the magnitude of density dependence in shell growth of 3 infaunal bivalve species dominating the tropical intertidal benthic communities of Banc d'Arguin, Mauritania. Two of our focal species were filter feeders (Senilia senilis and Pelecyora isocardia) and one was a facultative mixotroph (Loripes orbiculatus), mainly relying on organic carbon provided by sulphide-oxidizing endosymbiotic gill-bacteria (i.e. chemosymbiotic). Distinguishing 2 seasons,...
Tipo: Text
Palavras-chave: Carrying capacity; Chemosymbiosis; Density dependence; Environmental heterogeneity; Feeding guild; Seagrass; Soft-sediment habitat.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00492/60319/63745.pdf

Diversity of galling arthropods and host plants in a subtropical forest of Porto Alegre, southern Brazil
Provedor de dados: 82
Autores: Dalbem,Ricardo V.; Mendonça Jr.,Milton de S.
Many hypotheses have been proposed to explain diversity patterns of galling insects. However, there are contradictory evidences on the evolutionary and ecological factors responsible for the trends. Furthermore, questions such as arthropod seasonality, sampling sufficiency and sampling team experience have been almost ignored. This study records galling arthropod diversity while paying attention to these questions. Seasonal sampling of galling arthropods and host plants were conducted in a humid subtropical forest of southern Brazil. Four transects were sampled twice per season, with two persons searching the vegetation for galls during 1h30min. After 96h.persons of sampling, 130 gall morphotypes on 84 species of host plants were recorded. An analysis of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Morphotype; Sampler; Environmental heterogeneity; Seasonality.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2006000500007

Trophic organization and fish assemblage structure as disturbance indicators in headwater streams of lower Sorocaba River basin, São Paulo, Brazil
Provedor de dados: 83
Autores: Cruz,Bruna Botti; Teshima,Fernanda Ayumi; Cetra,Mauricio.
Studies that investigate the relationship patterns between environmental structure complexity and fish fauna provide crucial information to stream restoration efforts. In order to test the hypothesis that streams with more complex environmental structure sustain more diverse and functionally more complex fish communities we sampled fish fauna from Sorocaba River headwater stream reaches (SE - Brazil). Reaches represented two distinct treatments: (1) a simplified reach, characterized by unstable fine substrate, clay, deeper channel and higher water velocity and (2) structurally complex reaches, characterized by coarse substrate, with gravel, pebble, rock, stems and branches and leaves inside the channel, producing a diverse pattern of microhabitat,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bioindicators; Environmental heterogeneity; Functional group.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000100171

Species-specific associations between overstory and understory tree species in a semideciduous tropical forest
Provedor de dados: 39
Autores: Souza,Flaviana Maluf; Gandolfi,Sergius; Rodrigues,Ricardo Ribeiro.
We investigated the occurrence of associations between overstory and understory tree species in a semideciduous tropical forest. We identified and measured all trees of nine canopy species with diameter at breast height ≥4.8 cm in a 10.24 ha plot and recorded all individuals beneath their canopies ("understory individuals") within the same diameter class. The total density of understory individuals did not significantly differ under different overstory species. One overstory species (Ceiba speciosa) showed higher understory species richness compared with five other species. There was a strong positive association between three overstory species (Esenbeckia leiocarpa, Savia dictyocarpa, and C. speciosa) and the density of seven understory species...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Environmental heterogeneity; Facilitation; Plant-plant interaction; Rarefaction; Species richness.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062015000100073

Species composition, diversity, and vegetation structure in a gallery forest-cerrado sensu stricto transition zone in eastern Mato Grosso, Brazil
Provedor de dados: 39
Autores: Lenza,Eddie; Santos,Josias O.; Maracahipes-Santos,Leonardo.
ABSTRACTWe investigated the existence of an ecotone in the species composition, diversity and vegetation structure in the transition between gallery forest and cerrado sensu strictoin central Brazil. We tested two hypotheses: 1) a ecotone can be found between gallery forest and cerrado; 2) a gradient exists in the species composition of the cerrado. We established three parallel transects of 5 m × 350 m running between gallery forest and cerrado, which were divided into subplots of 5 m × 10 m, perpendicular to the margin of the Bacaba stream in Nova Xavantina (Mato Grosso, Brazil). We identified and measured the height and diameter of individual plants in the plots with a diameter of at least 3 cm at 30 cm above the ground. We recorded 140 species, of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brazilian savanna; Continuum; Environmental heterogeneity; Species turnover; Vegetation type.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062015000300327

Structure of molluscan assemblages in sheltered intertidal unconsolidated environments
Provedor de dados: 52
Autores: Denadai,Márcia Regina; Amaral,Antonia Cecilia Zacagnini; Turra,Alexander.
The molluscan macrofauna from 13 oceanic sheltered intertidal unconsolidated environments and its relationship with abiotic factors were studied in order to establish the degree of species richness and to understand the role environment plays in structuring such assemblages. Four distinct intertidal habitat types were recognized based on molluscan assemblage descriptors (diversity, richness and density) and abiotic characteristics. The mean grain size (in phy units) and the beach slope showed a negative relationship with the diversity, richness and density. Coarser sediments were favorable to molluscan fauna in the study areas, contrasting the well-known negative effect of this type of sand on fauna in typical oceanic beaches. The low-tide terraces,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Intertidal; Molluscan assemblage; Beach structure; Environmental heterogeneity.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000600019