scholarly journals Multi-scale comparisons of tree composition in Amazonian terra firme forests

2009 ◽  
Vol 6 (11) ◽  
pp. 2719-2731 ◽  
Author(s):  
E. N. Honorio Coronado ◽  
T. R. Baker ◽  
O. L. Phillips ◽  
N. C. A. Pitman ◽  
R. T. Pennington ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Soil Fertility ◽  
Regional Scale ◽  
Floristic Composition ◽  
Species Level ◽  
Geographical Distance ◽  
Terra Firme ◽  
Floristic Similarity ◽  
North Western ◽  
Scale Variation

Abstract. We explored the floristic composition of terra firme forests across Amazonia using 55 plots. Firstly, we examined the floristic patterns using both genus- and species-level data and found that the species-level analysis more clearly distinguishes among forests. Next, we compared the variation in plot floristic composition at regional- and continental-scales, and found that average among-pair floristic similarity and its decay with distance behave similarly at regional- and continental-scales. Nevertheless, geographical distance had different effects on floristic similarity within regions at distances <100 km, where north-western and south-western Amazonian regions showed greater floristic variation than plots of central and eastern Amazonia. Finally, we quantified the role of environmental factors and geographical distance for determining variation in floristic composition. A partial Mantel test indicated that while geographical distance appeared to be more important at continental scales, soil fertility was crucial at regional scales within western Amazonia, where areas with similar soil conditions were more likely to share a high number of species. Overall, these results suggest that regional-scale variation in floristic composition can rival continental-scale differences within Amazonian terra firme forests, and that variation in floristic composition at both scales is influenced by geographical distance and environmental factors, such as climate and soil fertility. To fully account for regional-scale variation in continental studies of floristic composition, future floristic studies should focus on forest types poorly represented at regional scales in current datasets, such as terra firme forests with high soil fertility in north-western Amazonia.

scholarly journals Integrating regional and continental scale comparisons of tree composition in Amazonian terra firme forests

2009 ◽  
Vol 6 (1) ◽  
pp. 1421-1451 ◽  
Author(s):  
E. N. Honorio Coronado ◽  
T. R. Baker ◽  
O. L. Phillips ◽  
N. C. A. Pitman ◽  
R. T. Pennington ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Regional Scale ◽  
Floristic Composition ◽  
Species Level ◽  
Terra Firme ◽  
Floristic Similarity ◽  
Continental Scale ◽  
Dependent Processes ◽  
North Western ◽  
Scale Variation

Abstract. We contrast regional and continental-scale comparisons of the floristic composition of terra firme forest in South Amazonia, using 55 plots across Amazonia and a subset of 30 plots from northern Peru and Ecuador. Firstly, we examine the floristic patterns using both genus- or species-level data and find that the species-level analysis more clearly distinguishes different plot clusters. Secondly, we compare the patterns and causes of floristic differences at regional and continental scales. At a continental scale, ordination analysis shows that species of Lecythidaceae and Sapotaceae are gradually replaced by species of Arecaceae and Myristicaceae from eastern to western Amazonia. These floristic gradients are correlated with gradients in soil fertility and to dry season length, similar to previous studies. At a regional scale, similar patterns are found within north-western Amazonia, where differences in soil fertility distinguish plots where species of Lecythidaceae, characteristic of poor soils, are gradually replaced by species of Myristicaceae on richer soils. The main coordinate of this regional-scale ordination correlates mainly with concentrations of available calcium and magnesium. Thirdly, we ask at a regional scale within north-western Amazonia, whether soil fertility or other distance dependent processes are more important for determining variation in floristic composition. A Mantel test indicates that both soils and geographical distance have a similar and significant role in determining floristic similarity across this region. Overall, these results suggest that regional-scale variation in floristic composition can rival continental scale differences within Amazonian terra firme forests, and that variation in floristic composition at both scales is dependent on a range of processes that include both habitat specialisation related to edaphic conditions and other distance-dependent processes. To fully account for regional scale variation in continental studies of floristic composition, future floristic studies should focus on forest types poorly represented at regional scales in current datasets such as terra firme forests with high soil fertility from north-western Amazonia.

scholarly journals Environment drives high phylogenetic turnover among oceanic bacterial communities

2012 ◽  
Vol 8 (4) ◽  
pp. 562-566 ◽  
Author(s):  
Thomas Pommier ◽  
Emmanuel J. P. Douzery ◽  
David Mouillot
Keyword(s):  
Bacterial Communities ◽  
Environmental Gradient ◽  
Regional Scale ◽  
Environmental Filtering ◽  
Species Level ◽  
Geographical Distance ◽  
Abiotic Conditions ◽  
High Connectivity ◽  
Phylogenetic Lineages ◽  
Marine Microbial Communities

Although environmental filtering has been observed to influence the biodiversity patterns of marine bacterial communities, it was restricted to the regional scale and to the species level, leaving the main drivers unknown at large biogeographic scales and higher taxonomic levels. Bacterial communities with different species compositions may nevertheless share phylogenetic lineages, and phylogenetic turnover (PT) among those communities may be surprisingly low along any biogeographic or environmental gradient. Here, we investigated the relative influence of environmental filtering and geographical distance on the PT between marine bacterial communities living more than 8000 km apart in contrasted abiotic conditions. PT was high between communities and was more structured by local environmental factors than by geographical distance, suggesting the predominance of a lineage filtering process. Strong phenotype-environment mismatches observed in the ocean may surpass high connectivity between marine microbial communities.

scholarly journals Changes in the floristic composition of a Terra Firme rain forest In Brazilian Amazonia over an eight-year period In response to logging

2002 ◽  
Vol 32 (2) ◽  
pp. 277-277 ◽  
Author(s):  
João Olegário Pereira de CARVALHO
Keyword(s):  
Rain Forest ◽  
Floristic Composition ◽  
National Forest ◽  
Terra Firme ◽  
Permanent Sample Plots ◽  
Brazilian Amazonia ◽  
Number Of Species

Changes in the floristic composition over an eight-year period in a logged area at the Tapajós National Forest in Brazilian Amazonia arc discussed. Two treatments of different intensities of logging were compared with an undisturbed (control) forest. Data were collected from permanent sample-plots. The effects of logging on floristic composition were stronger in the more heavily logged treatment. The number of species decreased immediately after logging, but started to increase before the fifth year after logging and was higher at the end of the study period than before logging. The more heavily logged plots responded more to disturbances, as judged by the increase in the number of species during the period after logging. This forest appears to recover its initial floristic composition after disturbance without intervention.

scholarly journals Short-term community dynamics in seasonal and hyperseasonal cerrados

2009 ◽  
Vol 69 (2) ◽  
pp. 231-240 ◽  
Author(s):  
MV. Cianciaruso ◽  
MA. Batalha
Keyword(s):  
Rainy Season ◽  
Community Dynamics ◽  
Plant Density ◽  
Floristic Composition ◽  
Species Density ◽  
Environmental Filters ◽  
Floristic Similarity ◽  
Different Seasons ◽  
Cylindrical Volume ◽  
Vegetation Form

In South America, the largest seasonal savanna region is the Brazilian cerrado. Our aim was to study temporal changes in some community descriptors, such as floristic composition, richness, species density, plant density, and cylindrical volume, in a seasonal cerrado, comparing it to a nearby hyperseasonal cerrado. In four different seasons, we placed randomly ten 1 m² quadrats in each vegetation form and sampled all the vascular plants. Seasonal changes in floristic composition, species density, and plant density were less pronounced in the seasonal than in the hyperseasonal cerrado. Floristic similarity between the vegetation forms was lower when the hyperseasonal cerrado was waterlogged. Richness and species density were higher in the seasonal cerrado, which reached its biomass peak at mid rainy season. The hyperseasonal cerrado, in turn, reached its biomass peak at early rainy season and, despite the waterlogging, maintained it until late rainy season. In the hyperseasonal cerrado, waterlogging acts as an environmental filter restricting the number of cerrado species able to withstand it. The seasonal cerrado community was more stable than the hyperseasonal one. Our results corroborated the idea that changes in the environmental filters will affect floristic composition and community structure in savannas.

scholarly journals A Multidisciplinary Tool for the Development of a Regional-scale Geotechnical Model: A Case Study in the North-Western Adriatic Coastal Area

2016 ◽  
Vol 158 ◽  
pp. 546-551 ◽  
Author(s):  
Laura Tonni ◽  
Irene Rocchi ◽  
Nadia Pia Cruciano ◽  
María F. García Martínez ◽  
Luca Martelli ◽  
...  
Keyword(s):  
Coastal Area ◽  
Regional Scale ◽  
The North ◽  
North Western ◽  
Geotechnical Model

scholarly journals A modelling study of photochemical regimes over Europe: robustness and variability

2009 ◽  
Vol 9 (1) ◽  
pp. 1521-1560 ◽  
Author(s):  
M. Beekmann ◽  
R. Vautard
Keyword(s):  
Model Uncertainty ◽  
Mediterranean Basin ◽  
Western Europe ◽  
Regional Scale ◽  
Relative Sensitivity ◽  
Time Variability ◽  
Nox Emissions ◽  
The Mediterranean ◽  
North Western ◽  
The Mediterranean Basin

Abstract. The variability of the relative sensitivity to volatile organic compounds (VOC) or NOx emissions, the chemical regime, over Europe during summers 2001 to 2003 is simulated with a regional scale transport-chemistry model. The robustness of chemical regimes is shown. A VOC sensitive regime over North-Western Europe and a mainly NOx sensitive regime over the Mediterranean basin and Eastern Europe are found, confirming earlier published results. The chemical regime time variability, its robustness to several environmental factors (seasonality, interannual variability) and to model uncertainty are thoroughly analysed. The chemical regime spatial structure only slightly depends on the ozone target considered (daily ozone maximum or AOT40, SOMO35, ...). Differences between particular years and summer months are weak. Day to day variability is significant but does not change the occurrence of one or another chemical regime over North-Western Europe and the Mediterranean basin. Expected decreases in anthropogenic NOx emissions over Europe since the last and for the next few decades have shifted and will shift chemical regimes to more NOx sensitive. The predictive and explanatory use of chemical regime indicator species is also investigated. For all cases but near ship tracks over the Mediterranean basin, the spatial pattern of chemical regimes appears to be robust with respect to model uncertainty.

scholarly journals Abundance, diversity and distribution of macrophyte communities in neighboring lakes of different trophic states and morphology in north-central Greece

2011 ◽  
Vol 63 (3) ◽  
pp. 763-774 ◽  
Author(s):  
Chrisoula Pirini ◽  
Vasiliki Karagiannakidou ◽  
Savvas Charitonidis
Keyword(s):  
Environmental Factors ◽  
Aquatic Vegetation ◽  
Floristic Composition ◽  
Diversity Indices ◽  
North Central ◽  
Wetland Ecosystems ◽  
Central Greece ◽  
Clear Differentiation ◽  
Evenness Indices

The role of aquatic vegetation in wetland ecosystems is closely related with their abundance, diversity and distribution, which in turn represents synergy of various environmental factors. The floristic composition of the aquatic vegetation in two neighboring lakes (Vegoritida and Petron) in north-central Greece was investigated by means of 160 relev?s, which were recorded using the Braun-Blanquet method. The analysis of relev?s based on TWINSPAN clustering showed the existence of 10 plant communities from the Lemnetea, Potametea, Phragmito-Magnocaricetea and Juncetea maritimi classes. The most important environmental factors for the vegetation differentiation in the study area, according to the ordination diagram, are light intensity and water depth of the habitats. The plant species diversity was quantified with species richness, Shannon Diversity and evenness indices at a scale of each relev?, with a sampling size of 20 m2. There was a clear differentiation between the relev?s at the more eutrophic Petron Lake and those at Vegoritida Lake. The mean plot diversity was also calculated for each plant community, to enable comparison of the diversity indices among the communities at the plot level.

scholarly journals How Bovine Livestock Affects Seed Rain in Subtropical Climate Forest

2019 ◽  
Vol 11 (10) ◽  
pp. 240
Author(s):  
Maureen de Moraes Stefanello ◽  
Ana Paula Moreira Rovedder ◽  
Roselene Marostega Felker ◽  
Matheus Degrandi Gazzola ◽  
Betina Camargo ◽  
...  
Keyword(s):  
Diversity Index ◽  
Morphological Characteristics ◽  
Floristic Composition ◽  
Seed Rain ◽  
Subtropical Climate ◽  
Floristic Similarity ◽  
Management Regime ◽  
Pampa Biome ◽  
Forest Remnants ◽  
History Of

Seed rainfall may be one of the mechanisms most impacted by livestock production in forest remnants. The trampling and cattle grazing alter dynamics, structure and floristic composition of the forest. The present work characterized the seed rainin forest remnants and the possible impacts of the presence and the management regime with different cattle stocks in the Pampa biome, southern region of Brazil. We compared three areas in Seasonal Forest remnants with a management history of 43 years: cattle exclusion area (A1); area with a cattle stock of 0.5 ua ha-1 (A2); and area with cattle stock of 1.0 ua ha-1 (A3). The seed rain was collected quarterly in 16 collectors (1 &times; 1 m&sup2;) per area for 24 months. The seeds were counted and identified according to external morphological characteristics, habit and dispersion syndrome. Shannon diversity index, submitted to the Hutcheson test, Pielou evenness, expected diversity and floristic similarity were determined. The results indicated that the impacts caused by livestock to seed rain were more significant in A3 where a quantitative reduction in the number of seeds was observed, probably due to the low number of plant individuals that make up the community.

scholarly journals FLORISTIC COMPOSITION AND DIVERSITY IN TERRA FIRME FOREST UNDER WATER STRESS IN THE AMAZON

CERNE ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 403-412
Author(s):  
Ana Maria Moreira Fernandes ◽  
Maria de Lourdes Pinheiro Ruivo ◽  
Antônio Carlos Lola Costa
Keyword(s):  
Water Stress ◽  
Floristic Composition ◽  
Terra Firme ◽  
Terra Firme Forest

scholarly journals Diferentes distúrbios antrópicos na paisagem podem influenciar padrões florísticos e estruturais da Mata Atlântica?

2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Elisa Morais Paschoal ◽  
Arthur Duarte Vieira ◽  
Thiago José Ornelas Otoni ◽  
Aglaia Maciel Gripp ◽  
Jessica Pereira Freire ◽  
...  
Keyword(s):  
Structural Component ◽  
Basal Area ◽  
Floristic Composition ◽  
Semideciduous Forest ◽  
Floristic Similarity ◽  
Alpha And Beta Diversity ◽  
Intermediate Disturbance ◽  
Tree Communities ◽  
Environmental Variations ◽  
Tree Component

This study aimed to describe and compare the floristic and structural component of the tree component, as well as the alpha and beta diversity, as well as the floristic similarity of a remnant of Semideciduous Forest. The tree vegetation was sampled at two edges in contact with pasture (BP) and coffee growing (BC), and inside the fragment (INT). 2.840 individuals were sampled, identified in 56 families, 144 genera and 271 species (94 BC, 128 BP and 178 INT). The border stretches were characterized by higher density and smaller basal area than the interior, indicating the occurrence of disturbances. The variations in the structural floristic composition of the tree communities wereinfluenced by regional and local environmental variations, as well as the historical use of the area, according to Niche and Intermediate Disturbance Theories.

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