Analysis of floristical and environmental gradients in the longitudinal profile of the Loire (France). The use of riparian plant species for a biotypological river-zone classification

2008 ◽  
Vol 109 (3-4) ◽  
pp. 291-312 ◽  
Author(s):  
R. Wisskirchen ◽  
S. Kisteneich ◽  
S. Krause
Keyword(s):  
Plant Species ◽  
Environmental Gradients ◽  
Longitudinal Profile ◽  
Riparian Plant

scholarly journals Reproductive phenology in a riparian rainforest in the south of Santa Catarina state, Brazil

2013 ◽  
Vol 85 (4) ◽  
pp. 1449-1460 ◽  
Author(s):  
MAINARA F. CASCAES ◽  
VANILDE CITADINI-ZANETTE ◽  
BIRGIT HARTER-MARQUES
Keyword(s):  
Plant Species ◽  
Resource Availability ◽  
Forest Ecosystems ◽  
Seasonal Pattern ◽  
Riparian Forests ◽  
Reproductive Phenology ◽  
Environmental Restoration ◽  
Fruit Availability ◽  
One Year ◽  
Riparian Plant

Phenological studies assist in forest ecosystems comprehension and evaluation of resource availability for wildlife, as well as in improving the understanding of relationships between plants and their pollinators and dispersers. This study aims to describe the reproductive phenophases of riparian plant species and correlate them with climatic variables. The reproductive phenology was analyzed biweekly throughout one year, recording the absence or presence of flowers/fruits. The flowering phenophase occurred throughout the year, with an increase in number of species in blossom in October, November, and December. The flowering peak of the community was observed in November. The fruiting phenophase also occurred throughout the year and showed an increase of species fruiting in June with a slight decrease in August and September. The data obtained in this study, when compared with other studies in different Atlantic Rainforest areas, indicates a seasonal pattern for the flowering phenophase and a variation in fruit availability throughout the year as well as in the fruiting peaks. Therefore, studies that observe flowering and fruiting events in loco are of main importance because they provide information on reproductive seasons of species for use in environmental restoration projects and thus alleviate the situation of degradation of riparian forests.

scholarly journals Evaluation of genetic isolation within an island flora reveals unusually widespread local adaptation and supports sympatric speciation

2014 ◽  
Vol 369 (1648) ◽  
pp. 20130342 ◽  
Author(s):  
Alexander S. T. Papadopulos ◽  
Maria Kaye ◽  
Céline Devaux ◽  
Helen Hipperson ◽  
Jackie Lighten ◽  
...  
Keyword(s):  
Gene Flow ◽  
Local Adaptation ◽  
Plant Species ◽  
Environmental Gradients ◽  
Isolation By Distance ◽  
Model Averaging ◽  
Dispersal Limitation ◽  
Population Divergence ◽  
Environmental Pressures ◽  
Isolation By Environment

It is now recognized that speciation can proceed even when divergent natural selection is opposed by gene flow. Understanding the extent to which environmental gradients and geographical distance can limit gene flow within species can shed light on the relative roles of selection and dispersal limitation during the early stages of population divergence and speciation. On the remote Lord Howe Island (Australia), ecological speciation with gene flow is thought to have taken place in several plant genera. The aim of this study was to establish the contributions of isolation by environment (IBE) and isolation by community (IBC) to the genetic structure of 19 plant species, from a number of distantly related families, which have been subjected to similar environmental pressures over comparable time scales. We applied an individual-based, multivariate, model averaging approach to quantify IBE and IBC, while controlling for isolation by distance (IBD). Our analyses demonstrated that all species experienced some degree of ecologically driven isolation, whereas only 12 of 19 species were subjected to IBD. The prevalence of IBE within these plant species indicates that divergent selection in plants frequently produces local adaptation and supports hypotheses that ecological divergence can drive speciation in sympatry.

Effects of salinisation on riparian plant communities in experimental catchments on the Collie River, Western Australia

2003 ◽  
Vol 51 (6) ◽  
pp. 667 ◽  
Author(s):  
A. J. Lymbery ◽  
R. G. Doupé ◽  
N. E. Pettit
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Western Australia ◽  
Soil Salinity ◽  
Riparian Vegetation ◽  
Plant Species Richness ◽  
Perennial Herb ◽  
Groundwater Levels ◽  
Riparian Plant Communities ◽  
Riparian Plant

Although the salinisation of streams has long been recognised as one of Western Australia's most serious environmental and resource problems, there is very little published information on the effects of salinisation on riparian flora and fauna. We studied riparian vegetation in three experimental catchments on the Collie River in Western Australia. The catchments are situated within a 5-km area of state forest and are geologically and botanically similar, but differ in the extent of clearing, groundwater levels and stream salinity. In each catchment, transects were taken perpendicular to the direction of streamflow, and 4-m2 quadrats taken along each transect. Within each quadrat, soil salinity was measured, all plants were identified to species level and percentage cover estimated. The catchments differed significantly in soil salinity, with salinity being greatest in the most extensively cleared catchment and increasing towards the floor of the valley. Plant-species richness, species diversity and species composition were significantly related to soil salinity, both among catchments and among quadrats within the most extensively cleared catchment. Plant-species richness and diversity decreased with increasing soil salinity, an effect that may be partly due to a decline in perennial herb and shrub species. This may have an impact on other components of the riparian ecosystem.

Positive relationships between invasive purple loosestrife (Lythrum salicaria) and plant species diversity and abundance in Minnesota wetlands

2004 ◽  
Vol 82 (6) ◽  
pp. 763-773 ◽  
Author(s):  
Heather A Hager ◽  
Rolf D Vinebrooke
Keyword(s):  
Plant Species ◽  
Plant Community ◽  
Native Species ◽  
Plant Density ◽  
Environmental Gradients ◽  
Lythrum Salicaria ◽  
Plant Invaders ◽  
Species Invasions ◽  
Density And Biomass ◽  
Diverse Plant

Plant species invasions may result from, and cause, changes in the vegetation community and abiotic environment. It is often hypothesized that nonnative plant invaders suppress the diversity of native species. We examined relationships of vegetation and environmental gradients associated with the nonnative invasive wetland plant Lythrum salicaria L. to determine whether L. salicaria invasion is associated with reduced diversity and abundance of resident plant species in the wetland community. Vegetation and environmental variables were surveyed in 10 wetlands defining a gradient of L. salicaria abundance. In addition, relationships among variables were compared between invaded, Lythrum-dominated and uninvaded, Typha-dominated patches within 6 of the 10 invaded wetlands. Contrary to expectations, ordination results showed that plant diversity was higher in invaded than in uninvaded patches. Lythrum salicaria replaced other plant density and biomass on a one-to-one basis. The ordination results generated an unexpected competing set of testable hypotheses regarding whether L. salicaria invades diverse plant communities or enhances plant community diversity.Key words: invasion, Lythrum salicaria, ordination, plant community composition, Typha-dominated marshes, wetlands.

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