Seed dispersal by red howling monkeys (Alouatta seniculus) in the tropical rain forest of French Guiana

1996 ◽  
Vol 17 (2) ◽  
pp. 239-258 ◽  
Author(s):  
C. Julliot
Keyword(s):  
Seed Dispersal ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
French Guiana ◽  
Alouatta Seniculus ◽  
Howling Monkeys

La phénologie des arbres caducifoliés en forêt guyanaise (5° de latitude nord) : illustration d'un déterminisme à composantes endogène et exogène

1994 ◽  
Vol 72 (12) ◽  
pp. 1843-1857 ◽  
Author(s):  
Denis Loubry
Keyword(s):  
Key Words ◽  
Tree Species ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
French Guiana ◽  
Dry Season ◽  
Deciduous Tree ◽  
Leaf Fall

The French Guianan forest is an evergreen rain forest that contains approximately 100 deciduous tree species. The taxonomical distribution of the deciduous character is widely spread, and its presence or absence among some taxa, as well as its ancient origin, are arguments in favour of an endogenous origin. Leaf-fall periodicity was studied on a sample of 500 trees during a 2-year period. Periodicity is annual and seasonal. It is not correlated to rainfall and not linked to the occurrence of a dry season. It seems closely correlated to photoperiodical variations, even though those variations are weak (35 min at latitude 5°30′N). However, each tree has its own periodicity for leaves shedding. Therefore, there is a paradox between seasonality and individual periodicity of leaf fall. The existence of this paradox leads us to consider the hypothesis of an integration of endogenous and exogenous components in the determination of leaf-fall periodicity. Key words: deciduousness, French Guiana, phenology, photoperiodism, tree, tropical rain forest.

Spatial variation of soil respiration across a topographic gradient in a tropical rain forest in French Guiana

2006 ◽  
Vol 22 (5) ◽  
pp. 565-574 ◽  
Author(s):  
Daniel Epron ◽  
Alexandre Bosc ◽  
Damien Bonal ◽  
Vincent Freycon
Keyword(s):  
Soil Respiration ◽  
Spatial Variation ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Root Biomass ◽  
French Guiana ◽  
Field Experiments ◽  
Mechanistic Models ◽  
Soil Carbon Content ◽  
Lateral Drainage

The objective of this study was to analyse the factors explaining spatial variation in soil respiration over topographic transects in a tropical rain forest of French Guiana. The soil of 30 plots along six transects was characterized. The appearance of the ‘dry to the touch’ character at a depth of less than 1.2 m was used to discriminate soils exhibiting vertical drainage from soils exhibiting superficial lateral drainage and along with colour and texture, to define five classes from well-drained to strongly hydromorphic soils. Spatial variation in soil respiration was closely related to topographic position and soil type. Increasing soil water content and bulk density and decreasing root biomass and soil carbon content explained most of the decrease in soil respiration from the plateaux (vertically drained hypoferralic acrisol) to the bottomlands (haplic gleysol). These results will help to stratify further field experiments and to identify the underlying determinants of spatial variation in soil respiration to develop mechanistic models of soil respiration.

Sign in / Sign up

Export Citation Format

Share Document