Multivariate analysis of plant communities in the Narok district, Kenya: The influence of environmental factors and human disturbance

Vegetatio ◽  
1996 ◽  
Vol 126 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Z. A. Ogutu
Keyword(s):  
Multivariate Analysis ◽  
Environmental Factors ◽  
Plant Communities ◽  
Human Disturbance

Multivariate Analysis of Plant Communities and Environmental Factors in Ngari, Tibet

Ecology ◽  
1986 ◽  
Vol 67 (6) ◽  
pp. 1568-1575 ◽  
Author(s):  
D. H. S. Chang ◽  
H. G. Gauch
Keyword(s):  
Multivariate Analysis ◽  
Environmental Factors ◽  
Plant Communities

scholarly journals Distribution of saltmarsh plant communities associated with environmental factors along a latitudinal gradient on the south-west Atlantic coast

2006 ◽  
Vol 33 (5) ◽  
pp. 888-900 ◽  
Author(s):  
J. P. Isacch ◽  
C. S. B. Costa ◽  
L. Rodriguez-Gallego ◽  
D. Conde ◽  
M. Escapa ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Plant Communities ◽  
Latitudinal Gradient ◽  
Atlantic Coast ◽  
The South ◽  
South West

Sur l'organisation phytochimique de formations prairiales permanentes

2001 ◽  
Vol 79 (4) ◽  
pp. 510-519 ◽  
Author(s):  
Philippe Lebreton ◽  
Bernard Jeangros ◽  
Christiane Gallet ◽  
Jan Scehovic
Keyword(s):  
Cell Wall ◽  
Multivariate Analysis ◽  
Plant Communities ◽  
Nutrient Pool ◽  
Grassland Species ◽  
Anthriscus Sylvestris ◽  
Cool Environment ◽  
Mineral Components ◽  
Herbaceous Community ◽  
Food Value

Organic and mineral components have been analysed on 18 dicotyledonous species of permanent grassland communities. Multivariate analysis revealed an opposition between a macromolecular pool (cellulose and lignin) and a nutrient pool (potassium and phosphorus, nitrogen). The first pole is characterized by Tragopogon pratensis L. (Compositae) and Galium mollugo L. (Rubiaceae), the second by Anthriscus sylvestris (L.) Hoffm. (Umbelliferae) and Geranium sylvaticum L. (Geraniaceae). The most thermo-helio-xerophilous species (Knautia arvensis (L.) Coult and Tragopogon pratensis) belong to the first group, whereas the second group includes the cool-environment species (like Alchemilla xanthochlora Roth.), which reveals an ecophysiological determinism. Moreover, correlations between the biochemical and ecological structure, and other interrelated parameters, including sclerophylly, have been shown. Compared to lignous and sempervirent plant communities, the grassland species have lower phenolic and lignin contents but higher glucide and nutrient (potassium and phosphorus) contents, which is in accordance with their food value. For this herbaceous community, the C/N ratio indicates the same general equilibrium between cell-wall macromolecules and nitrogen than for two other plant communities (mainly ligneous) previously studied, with some differences revealing distinct trends from the same general metabolic sheme.Key words: dicotyledonous plant communities, biochemical organization, C/N ratio, ecophysiology.

scholarly journals Increase in the Risk of Respiratory Disorders in Adults and Children Related to Crop-Growing in Niger

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Mamane ◽  
Jean-François Tessier ◽  
Ghislaine Bouvier ◽  
Roger Salamon ◽  
Pierre Lebailly ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Environmental Factors ◽  
Respiratory Symptoms ◽  
Respiratory Health ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Face To Face ◽  
Increased Risk ◽  
Adults And Children ◽  
Agricultural Areas

Background and Objective. Environmental factors are an increasing concern for respiratory health in developing countries. The objective of this study was to investigate whether Nigerien people living in cultivated areas have more respiratory symptoms than those living in pastoral areas. Method. A cross-sectional study was conducted in 2013 in two populations during the rainy season when land is cultivated. Environmental factors including pesticide use and respiratory symptoms were collected in adults and children during face-to-face interviews. Multivariate analysis between exposures and symptoms was performed in children and in adults separately. Results. The study included 471 adults and 229 children. Overall, none of the households reported the use of pesticides for agricultural purposes. However, 87.2% reported the use of insecticides at home. Multivariate analysis showed that people living in agricultural areas compared to those in pastoral areas had an increased risk of respiratory symptoms in adults (wheezing, dyspnea, sudden shortness of breath, and cough without fever) and in children (cough without fever). The use of insecticides showed no effect on respiratory symptoms after adjustment. Conclusion. This first epidemiological study on the environment and respiratory health conducted in Niger demonstrates a significant relationship between respiratory manifestations and the agricultural characteristics of the living area. However only the effect of insecticides in the home on respiratory health was observed.

Multivariate Analysis in Genetic Studies

1972 ◽  
Vol 21 (3) ◽  
pp. 204-210 ◽  
Author(s):  
Ch. Susanne
Keyword(s):  
Multivariate Analysis ◽  
Environmental Factors ◽  
The Body ◽  
Biometrical Analysis ◽  
Genetic Studies ◽  
The Face ◽  
Generalized Distances ◽  
Sib Pairs

SummaryThe results are presented of a method of generalized distances calculated by a noncentral χ2 test and applied to compare 63 twin pairs and 196 sib pairs. The advantage of this method in biometrical analysis lies in the fact that several measurements can be utilised simultaneously. Besides, it takes into account the distance of each relative to the centre of the population and also has the advantage of permitting the comparison of distances between pairs of relatives whatever their age or sex.Generalized distances were calculated for four measurements of the head, five of the body and eleven of the face. For all three sets of measurements the influence of genetical factors was demonstrated. The body seems less influenced by environmental factors and more conditioned by genetic ones.

scholarly journals Increasing corvid tolerance to humans in urban ecosystems with increasing latitude

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Nadezhda Poddubnaya ◽  
Tatyana Korotkova ◽  
Polina Vanicheva
Keyword(s):  
Environmental Factors ◽  
Human Disturbance ◽  
Urban Ecosystems ◽  
Flight Initiation Distance ◽  
Protection Measures ◽  
Non Invasive ◽  
Alert Distance ◽  
Behaviour Changes ◽  
Hooded Crows ◽  
Flight Initiation

The rapid growth of cities causes behaviour changes in birds in response to urban environmental factors. The avian response to human disturbance has recently been studied by a non-invasive research tool as an alert distance (AD) and a flight initiation distance (FID) assessment. The tolerance of hooded crows (n = 395), jackdaws (n = 394) and rooks (n = 169) to humans was assessed by AD and FID. It was shown that the FID of all species is maximal during the summer, when the parents send clear “danger—fly away” signals to the young and the birds fly away. The AD and FID of the three species reliably correlates with the season. Rooks showed FID species-specificity in seven cities of Eastern Europe. Comparison of the attitude of birds to people in cities that have similarities in human culture showed that tolerance increases with increasing latitude in all species and is statistically significant only in the jackdaw. This should be taken into account in environmental protection measures.

scholarly journals The weed vegetation of the bean “Fagiolo Cannellino di Atina” and the red pepper “Peperone di Pontecorvo” PDO crops (Latium, central Italy)

2020 ◽  
Vol 57 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Marta Latini ◽  
Emanuele Fanfarillo ◽  
Elisa De Luca ◽  
Mauro Iberite ◽  
Giovanna Abbate
Keyword(s):  
Multivariate Analysis ◽  
Phaseolus Vulgaris ◽  
Environmental Factors ◽  
Capsicum Annuum ◽  
Central Italy ◽  
Agricultural Management ◽  
Red Pepper ◽  
Vegetation Types ◽  
Protected Designation Of Origin

The weed vegetation of the bean “Fagiolo Cannellino di Atina” (Phaseolus vulgaris L.) and the red pepper “Peperone di Pontecorvo” (Capsicum annuum L.) PDO (Protected Designation of Origin) crops was surveyed by means of 16 relevés, sampled in four farms of southern Latium during July 2019. The relevés were subjected to multivariate analysis, which revealed that the two crops are weeded by vegetation types referable to two different subassociations of Panico-Polygonetum persicariae (Spergulo-Erodion, Eragrostietalia, Digitario-Eragrostietea). Namely, communities colonizing bean fields, which are more mesophilous and richer in Eurasian taxa, are ascribable to the subassociation sorghetosum halepensis. Communities colonizing red pepper fields, which are more thermophilous and richer in Mediterranean taxa, are ascribable to the subassociation cyperetosum rotundi. Floristic, structural, and chorological features of the communities are discussed in relation to environmental factors and agricultural management.

scholarly journals A phytosociological analysis and synopsis of the dry woodlands and succulent vegetation of the Peruvian Andes

2016 ◽  
Vol 88 (suppl 1) ◽  
pp. 689-703 ◽  
Author(s):  
ANTONIO GALÁN-DE-MERA ◽  
ISIDORO SÁNCHEZ-VEGA ◽  
ELIANA LINARES-PEREA ◽  
JOSÉ CAMPOS ◽  
JUAN MONTOYA ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Plant Communities ◽  
Sandy Soils ◽  
Dry Forest ◽  
The Other ◽  
Humboldt Current ◽  
Peruvian Andes ◽  
New Associations ◽  
Coastal Desert

ABSTRACT A phytosociological approach to dry forest and cactus communities on the occidental slopes of the Peruvian Andes is presented in base of 164 plots carried out following the Braun-Blanquet method. From them, 52 have been made recently, and the other 112 were taken from the literature. After a multivariate analysis, using a hierarchical clustering and a detendred correspondence analysis, the Acacio-Prosopidetea class (dry forest and cactus communities, developed on soils with some edaphic humidity or precipitations derived from El Niño Current), the Opuntietea sphaericae class (cactus communities of central and southern Peru, on few stabilized rocky or sandy soils) and the Carico-Caesalpinietea class (dry forests of the Peruvian coastal desert, influenced by the maritime humidity of the cold Humboldt Current), are differentiated. Within the Acacio-Prosopidetea class, two alliances are commented: the Bursero-Prosopidion pallidae (with two new associations Loxopterygio huasanginis-Neoraimondietum arequipensis and Crotono ruiziani-Acacietum macracanthae), and the new alliance Baccharido-Jacarandion acutifoliae (with the new associations Armatocereo balsasensis-Cercidietum praecocis and Diplopterydo leiocarpae-Acacietum macracanthae). For the Opuntietea sphaericae class, the association Haageocereo versicoloris-Armatocereetum proceri (Espostoo-Neoraimondion) is described on the basis of plots from hyperarid localities of central Peru. Finally, a typological classification of the studied plant communities is given.

Wetland plant communities of turloughs in southeast Galway/north Clare, Ireland in relation to environmental factors

2007 ◽  
Vol 87 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Eugenie C. Regan ◽  
Micheline Sheehy Skeffington ◽  
Mike J. Gormally
Keyword(s):  
Environmental Factors ◽  
Plant Communities ◽  
Wetland Plant ◽  
Wetland Plant Communities
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