LES SENTIERS DE CARIBOUS DANS L’HEMIARCTIQUE, UN TYPE SECULAIRE DE BIOTOPE A LARVES DE MOUSTIQUES (CULICIDAE)

1980 ◽  
Vol 112 (10) ◽  
pp. 1007-1012
Author(s):  
Daniel Goyette ◽  
Alain Maire
Keyword(s):  
Chamaedaphne Calyculata ◽  
Composition Spécifique

RésuméLa région du lac Delorme, dans l’Hémiarctique québécois (55°00′N; 69°55′0), est parcourue par l’un des trois principaux troupeaux de caribous (Rangifer caribou) du centre de l’Ungava. Lors de leurs migrations, ces animaux tracent de nombreux sentiers qui, en périphérie des tourbières, constituent des gîtes à larves de moustiques. Une analyse qualitative et quantitative des populations larvaires présentes dans les portions de sentiers traversant les groupements sur tourbe à Carex oligosperma et à Chamaedaphne calyculata, indique que quatre espèces d’Aedes printaniers s’y développent de façon caractéristique. En comparant ces résultats à ceux provenant des mares naturelles réparties à travers ces deux groupements de tourbière, on peut conclure qu’il n’y a pas de différence notable dans la composition spécifique, l’abondance relative et la densité des populations culicidiennes de ces deux types de biotopes.

Studies of the Byron Bog in Southwestern Ontario. XI. Seasonal Distribution of Adult Insects in the Chamaedaphnetum calyculatae Association

1960 ◽  
Vol 92 (4) ◽  
pp. 241-251 ◽  
Author(s):  
W. W. Judd
Keyword(s):  
Seasonal Distribution ◽  
Chamaedaphne Calyculata

In the description of the Byron Bog (Judd, 1957c) it was pointed out that one method of collecting insects in the bog was to make a circular sweep with an insect net, held at arm's length, through the tops of the bushes in the Chamaedaphnetum calyculatae association. The net used was one with a rim twelve inches in diameter and the radius of the circle over which the sweep was made was six feet. A single sweep was made each day from Itlay 15 to November 15 in 1956 and all the insects collected each day were sorted and counted. The dav of maximum blooming of Chamaedaphne calyculata was May 21 and the day of last blooming was June 1 (Judd, 1958a). Thus there was a period of nineteen days, from May 15 to June 1, when the plants were in bloom while the sweeping was in progress.

The effect of smelting operations on peatlands near Sudbury, Ontario, Canada

1986 ◽  
Vol 64 (6) ◽  
pp. 1138-1147 ◽  
Author(s):  
L. Dennis Gignac ◽  
Peter J. Beckett
Keyword(s):  
Water Levels ◽  
Chamaedaphne Calyculata ◽  
Moss Layer

Accumulations of six metals (Cu, Ni, Mn, Al, Fe, and Ca) were analysed in peat and water for 18 peatlands east northeast of Falconbridge, Ontario, Canada. The peatlands had a minimum of 30 cm accumulation of peat, < 10 μg mL−1 Ca2+ in the water, and were from a variety of physiognomic dominance types. Significant correlations existed between the distance from smelting operations and the concentrations of Cu and Ni in the peat and water. Levels of Mn, Fe, and Ca were not related to distance. The vegetation was analysed on 11 of the 18 peatlands. With the exception of the two sites closest to the smelter, all are low shrub peatlands, dominated by Chamaedaphne calyculata. Effects on the vegetation range from severe within 2 km of the smelter to minimal at 30 km. Sphagnum species that normally dominate the moss layer of these peatlands begin to appear at approximately 12 km from the smelter and are found almost exclusively in the moat area. With increasing distance and decreasing concentrations of Cu and Ni, conditions gradually permit growth of the oligotrophic Sphagnum species. Beyond 30 km, Sphagnum dominates all portions of the peatlands.

Studies of the Byron Bog in Southwestern Ontario: IX. Insects Trapped as Adults Emerging from Redmond's Pond

1958 ◽  
Vol 90 (10) ◽  
pp. 623-627 ◽  
Author(s):  
W. W. Judd
Keyword(s):  
Lemna Minor ◽  
Thick Layer ◽  
Flax Seed ◽  
Spirodela Polyrhiza ◽  
Adjacent Edge ◽  
Chamaedaphne Calyculata ◽  
Northeast Corner ◽  
Utricularia Vulgaris

In the description of the Byron Bog (Judd, 1957a) it was pointed out that Redmond's Pond is situated in the northwest corner of the bog and that during 1956 a tent-trap was anchored in a small bay in the northeast corner of the pond to trap insects emerging as adults from the water. The position of the trap on the pond is shown in the map accompanying the description of the bog (Judd, 1957a) and the structure and use of the trap are also described by Judd (1957b). The trap was placed on the water on May 15, 1956 and remained there until November 8. It was about four feet from the edge of the pond in water about two feet deep. At this point the bottom of the pond was composed of a thick layer of loose, brown peat and the adjacent edge of the pond was occupied by a dense growth of leatherleaf, Chamaedaphne calyculata, growing in Sphagnum (Judd, 1957a). The branches of the bushes of leatherleaf extended out over the water of the small bay in which the trap floated. The only rooted plant growing in and around the trap was spatterdock, Nuphar advena. Floating in the water was a sparse growth of bladderwort, Utricularia vulgaris, and on the surface of the water there were a few scattered fronds of duckweed, Lemna minor, and water flax-seed, Spirodela polyrhiza.

ECOLOGICAL STUDY OF THE PEAT BOGS OF EASTERN NORTH AMERICA: III. NOTES ON THE BEHAVIOR OF CHAMAEDAPHNE CALYCULATA

1956 ◽  
Vol 34 (1) ◽  
pp. 197-207 ◽  
Author(s):  
Kornelius Lems
Keyword(s):  
Ecological Study ◽  
The Other ◽  
Soil Conditions ◽  
Peat Bogs ◽  
Eastern North America ◽  
Physiological Basis ◽  
Chamaedaphne Calyculata ◽  
Different Types ◽  
The One ◽  
The Relationship

This paper presents data and observations concerning Chamaedaphne calyculata (L.) Moench. (Ericaceae). The branching pattern, the longevity of different types of leaves, and features of flowering are shown to be correlated. The relationship between this complex of features and the habitat is studied, and a few speculations are advanced to explain the physiological basis for the behavior of Chamaedaphne. This study is essentially autecological, and it is hoped that it may constitute a link between the study of soil conditions and the response of plant hormones on the one hand, and phytosociological work in peat bogs on the other hand.

Heat tolerance of rhizomes of several understory species

1983 ◽  
Vol 61 (2) ◽  
pp. 452-457 ◽  
Author(s):  
Marguerite A. Flinn ◽  
Joan K. Pringle
Keyword(s):  
Temperature Tolerance ◽  
Pteridium Aquilinum ◽  
Tolerance Index ◽  
Understory Species ◽  
Chamaedaphne Calyculata ◽  
Cornus Canadensis ◽  
Shoot Number ◽  
Different Temperatures ◽  
Maianthemum Canadense ◽  
Study Sites

Rhizomes of eight understory species: Gaultheria procumbens, Maianthemum canadense, Vaccinium angustifolium, Cornus canadensis, Pteridium aquilinum, Kalmia angustifolia, Chamaedaphne calyculata, and Rhododendron canadense were subjected to treatments of 45, 50, 55 and 60 °C for 5 min in a water bath. Selection of these species for study was based on differences in the depth of the rhizomes, in habitat, and in rhizome morphology. Samples were collected from study sites located near Halifax, in the Nova Scotia Acadian Forest region.Maximum shoot growth occurred at different temperatures for the various species: 45 °C for Cornus canadensis; 50 °C for Chamaedaphne calyculata, R. canadense, and V. angustifolium; 55 °C for G. procumbens and M. canadense. Death occurred at or below 60 °C for most species. For comparative purposes, a temperature tolerance index (TTI) was calculated for each species. The TTI indicated that R. canadense and V. angustifolium showed the greatest tolerance to higher temperatures and that K. angustifolia and P. aquilinum showed the least tolerance. Mean shoot number increased significantly following spring treatments for all species except for Cornus canadensis which showed greater increase following autumn treatments.

scholarly journals Dynamique des peuplements ligneux dans le Parc National de Manda, au sud du Tchad

2019 ◽  
Vol 42.1 ◽  
pp. 7139-7152
Author(s):  
Guiguindibaye MADJIMBE ◽  
Goy SARADOUM ◽  
Touroumgaye GOALBAYE ◽  
Esaïe WAYA ◽  
Jonathan POUNAKOUMNA
Keyword(s):  
National Park ◽  
Basal Area ◽  
Average Density ◽  
Anthropogenic Pressure ◽  
Average Volume ◽  
Specific Composition ◽  
Gradual Evolution ◽  
Standing Timber ◽  
Composition Spécifique ◽  
Structure Des Peuplements

1 RÉSUMÉ La présente étude a pour but d’étude la dynamique des peuplements ligneux dans le Parc National de Manda. Elle vise à déterminer les caractéristiques structurales, la composition spécifique et la régénération des peuplements ligneux. Quatre sites ont été implantés depuis 2012. Nous avons procédé à la caractérisation des peuplements ligneux par des relevés dendrométriques. La flore ligneuse dans l’ensemble des sites est riche de 87 espèces reparties en 56 genres et 22 familles. Les sites 1 et 2 ont des effectifs plus élevés en 2019 comparativement en 2014 et en 2012. Une forte régénération s’est effectuée durant l’année 2019. Contrairement aux sites, 1 et 2, les sites 3 et 4 présentent pour l’année 2019 une forte baisse des effectifs de jeunes plants. Ces jeunes plants sont très sensibles non seulement à la disponibilité des ressources en eau pour franchir la saison sèche mais aussi à l’intensité et à la fréquence de passage des feux. Les résultats ont permis de noter que la densité moyenne entre 2012 et 2014 s’est accrue et à partir de 2014 elle s’est stabilisée. La surface terrière par hectare est, en moyenne de 10,12 m2/ha pour 2012 ; 11,16 m2/ha pour l’année 2014 et de 11, 65 m2/ha pour l’année 2019. Pour l’ensemble des sites expérimentaux, on évalue le volume moyen de bois sur pieds à 12,31 m3/ha en 2012, à 12,46 m3/ha en 2014 et 12,08 m3/ha en 2019. Ces valeurs indiquent que les variations de volume moyen de bois sur pieds sont très faibles pour les sites pris dans leur ensemble. Les résultats obtenus, montrent aussi que 8 espèces se situent dans un processus d’évolution régressive et 4 autres dans un processus d’évolution progressive. La structure des peuplements ligneux n’a pas beaucoup évolué en 8 ans mais, elle apparaît fortement tributaire de la topographie et de la pression anthropique. ABSTRACT Dynamic of the woody populations in the National Park of Manda, to the south of Chad The purpose of this study is to study the dynamics of woody stands in the Manda National Park. It aims to determine the structure, specific composition and regeneration of woody stands. Four sites have been established since 2012. We have characterized the woody stands by dendrometric surveys. The woody flora in all sites is rich in 87 species divided into 56 genera and 22 families. Sites 1 and 2 have higher numbers in 2019 compared to 2014 and 2012. Strong regeneration took place in 2019. Unlike sites 1 and 2, sites 3 and 4 present for the year 2019 a sharp decline in the number of young plants; these seedlings are very sensitive not only to the availability of water resources to cross the dry season but also to the intensity and frequency of fire. The results showed that the average density between 2012 and 2014 increased and from 2014 it stabilized. The basal area per hectare is, on average, 10.12 m2 / ha for 2012; 11.16 m2 / ha for the year 2014 and 11, 65 m2 / ha for the year 2019. For all the experimental sites, the average volume of standing timber is estimated at 12.31 m3/ ha in 2012, 12.46 m3 / ha in 2014 and 12.08 m3 / ha in 2019. These values indicate that variations in average volume of standing timber are very low for sites taken as a whole. The results obtained also show that 8 species are in a process of regressive evolution and 10 in a process of gradual evolution. The structure of woody stands has not changed much in 8 years, but it appears highly dependent on topography and anthropogenic pressure.

scholarly journals Chamaedaphne calyculata

1917 ◽  
Vol 3 (17) ◽  
pp. 68-68
Keyword(s):  
Chamaedaphne Calyculata

scholarly journals Diversité des essences et régénération de forêts communautaires à Sal (Shorea robusta) dans la région centrale du Népal

2009 ◽  
Vol 300 (300) ◽  
pp. 57
Author(s):  
Indra Prasad Sapkota ◽  
Mulualem Tigabu ◽  
Per Christer Oden
Keyword(s):  
Pinus Roxburghii ◽  
Shorea Robusta ◽  
Eugenia Jambolana ◽  
Composition Spécifique ◽  
Composition Floristique

Cette étude a porté sur la diversité et la régénération d¿essences forestières dans deux forêts communautaires à Sal (Shorea robusta) au centre du Népal, la forêt de plaine de Bhabar (LEF) et une forêt d¿altitude (HEF). Les essences de plus de 30 cm de hauteur ont été dénombrées sur 16 quadrats systématiquement délimités. La densité, la dominance et la fréquence ainsi que l¿indice des valeurs d¿importance (IVI) des essences ont été calculés afin de caractériser la composition floristique. La densité des peuplements, la surface terrière et des mesures de diversité ont été calculées afin d¿analyser la structure et l¿hétérogénéité des peuplements de chaque communauté forestière. Au total, 17 familles, 19 genres et 21 espèces étaient représentées dans la LEF. Pour la HEF, le total recensé est de 13, 18 et 21, respectivement. Les résultats de l¿étude indiquent que Shorea robusta est l¿essence la plus abondante aussi bien pour la LEF (IVI = 174,4%) que la HEF (IVI = 206,9%). Il ressort nettement de l¿étude une association de Shorea robusta, Schima wallichi et Syzygium operculatum dans la forêt LEF et de Shorea robusta, Pinus roxburghii et Eugenia jambolana dans la HEF. La densité des peuplements et la surface terrière de la LEF (13 231 tiges/ha, 34,30 m2/ha) est plus élevée que pour la HEF (7 787 tiges/ha, 20,69 m2/ha). Les indices de Shannon-Weiner et Simpson ont tout deux fait ressortir une densité plus importante pour la HEF (H¿= 2,42, 1 D = 0,64) que pour la LEF (H¿= 1,38, 1 D = 0,35). L¿état de régénération des deux forêts à Sal semble globalement satisfaisant, avec 38% et 33% de l¿ensemble des espèces de la LEF et la HEF, respectivement, représentées aux stades du plant et de la régénération avancée. L¿étude conclut que les variations en termes de composition spécifique, de diversité et de régénération s¿expliquent en partie par l¿altitude. (Résumé d'auteur)

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