scholarly journals Tree seedling performance in canopy gaps in a tropical rain forest at Nouragues, French Guiana

1998 ◽  
Vol 14 (2) ◽  
pp. 119-137 ◽  
Author(s):  
PETER J. VAN DER MEER ◽  
FRANK J. STERCK ◽  
FRANS BONGERS
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
French Guiana ◽  
Environmental Heterogeneity ◽  
Canopy Gaps ◽  
Gap Formation ◽  
Tree Seedling ◽  
Growth And Survival ◽  
Closed Forest ◽  
Forest Conditions

The effect of natural canopy gaps on the performance of naturally occurring tree seedling populations was studied in a tropical rain forest in French Guiana. This was done at two levels of scale. Firstly, on a 20 m × 250 m forest transect intersecting four canopy gaps, it was investigated how patterns of recruitment, growth and survival of seedlings of Cecropia obtusa, Dicorynia guianensis and Pourouma bicolor differed between canopy gaps and closed forest. Secondly, for one large natural canopy gap, performance of seedling cohorts established before (‘pre-gap’ cohorts) and after (‘post-gap’ cohorts) gap formation was studied in relation to environmental heterogeneity. The direct site factor (DSF) was used as an indicator of light availability in the gap zone. Cecropia specialised in large gaps, and also in specific sites within the large gap: seedling performance was increased by light, and by dead wood. Pourouma mainly germinated under closed forest conditions, where it can survive for a long period until a canopy gap is formed nearby. Pourouma seedlings adjusted well to the new gap environment but they did not specialise in specific places within the gap. Seedling location of Pourouma seedlings was mainly determined by accidental positioning before gap formation. Dicorynia was able to germinate both in gaps and under closed forest conditions. Although the number of gaps studied in this study was low, the results show that seedling establishment, early growth and survival of the three tree species were affected by canopy gaps and by the environmental heterogeneity within a large gap.

Irradiance and Spectral Quality Affect Asian Tropical Rain Forest Tree Seedling Development

Ecology ◽  
1995 ◽  
Vol 77 (2) ◽  
pp. 568-580 ◽  
Author(s):  
David W. Lee ◽  
Krishnapillay Baskaran ◽  
Marzalina Mansor ◽  
Haris Mohamad ◽  
Son Kheong Yap
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Forest Tree ◽  
Seedling Development ◽  
Spectral Quality ◽  
Tree Seedling

The estimation of temporal processes in tropical rain forest: a study of primary mixed dipterocarp forest in Indonesia

1985 ◽  
Vol 1 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Soedarsono Riswan ◽  
J. B. Kenworthy ◽  
Kuswata Kartawinata
Keyword(s):  
Time Scale ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Gap Formation ◽  
Growth Rings ◽  
Secondary Species ◽  
East Kalimantan ◽  
Forest Sites ◽  
Time Required ◽  
Individual Trees

ABSTRACTIn the absence of growth rings it is difficult to give a precise time scale for processes associated with the re-establishment of tropical rain forest. This paper explores other methods by which a time scale may be constructed. The proportions of primary and secondary species, an index of similarity, biomass measurements, girth dimensions and gap size are all considered from sites in East Kalimantan, Indonesia. Data from primary, secondary and experimentally cleared forest sites are compared to estimate the minimum time required for various phases involved in the re-establishment of tropical rain forest after disturbance. A simple model is proposed to accommodate the data and other estimates in the literature. The model predicts a minimum period for the stablization of secondary species numbers as 60–70 years and the replacement of primary species as 150 years at which point gap formation is initiated. After approximately 220–250 years biomass stabilizes while individual trees exist for over 500 years.

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.

Butterfly behavioural responses to natural Bornean tropical rain-forest canopy gaps

2011 ◽  
Vol 28 (1) ◽  
pp. 45-54 ◽  
Author(s):  
James S. Pryke ◽  
Sven M. Vrdoljak ◽  
Paul B. C. Grant ◽  
Michael J. Samways
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Forest Canopy ◽  
Canopy Gaps ◽  
Tree Canopy ◽  
Canopy Openness ◽  
Butterfly Species ◽  
Behavioural Responses ◽  
Light Heterogeneity ◽  
Closed Canopy

Abstract:Natural tree canopy gaps allow sunlight to penetrate to the forest floor, a major environmental component and resource for many tropical rain-forest species. We compare here how butterflies use sunny areas created by the natural gaps in canopies in comparison with adjacent closed-canopy areas. We chose butterflies as our focal organisms as they are taxonomically tractable and mobile, yet habitat sensitive. Previous studies have shown that butterfly diversity in tropical forests responds to varying degrees of canopy openness. Here we assess butterfly behavioural responses to gaps and equivalent sized closed-canopy patches. Butterfly occupancy time and behaviour were simultaneously observed 61 times in gaps and 61 times in equivalent sized closed-canopy patches across four sites in a tropical rain forest in northern Borneo. Out of the 20 most frequently recorded species, 12 were more frequently recorded or spent more time in gaps, four occurred more frequently in closed-canopy areas, and four showed no significant differences. Overall agonistic, basking, patrolling and resting were more common in gaps compared with the closed canopy. Many butterfly species have complex behavioural requirements for both gaps and closed canopies, with some species using these different areas for different behaviours. Each butterfly species had particular habitat requirements, and needed both canopy gaps and closed canopy areas for ecological and behavioural reasons, emphasizing the need for natural light heterogeneity within these systems.

Formation and closure of canopy gaps in the rain forest at Nouragues, French Guiana

Vegetatio ◽  
1996 ◽  
Vol 126 (2) ◽  
pp. 167-179 ◽  
Author(s):  
P. J. Meer ◽  
F. Bongers
Keyword(s):  
Rain Forest ◽  
French Guiana ◽  
Canopy Gaps

Do dipterocarp seedlings really partition tropical rain forest gaps?

1992 ◽  
Vol 335 (1275) ◽  
pp. 369-378 ◽  
Keyword(s):  
Rain Forest ◽  
Seedling Survival ◽  
Canopy Gaps ◽  
Forest Recovery ◽  
Canopy Openness ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Regeneration Dynamics ◽  
Closed Forest ◽  
Survival And Growth

The theory of gap regeneration dynamics proposes that different species of tree partition canopy gaps because they are preferentially adapted to a particular gap size class. A variety of gap sizes would therefore favour the regeneration of a range of species. The theory has been used to explain the extraordinarily high tree species diversity of tropical rain forests. A test was mounted in lowland evergreen dipterocarp rain forest in the Danum Valley, Sabah, East Malaysia by the creation of ten, artificial canopy gaps ranging in size from 10 m 2 to 1500 m 2 (6 to 30% canopy openness). The responses of established populations of seedlings of three dipterocarp species ( Hopea nervosa , Parashorea malaanonan and Shorea johorensis ) with contrasting silvicultural reputations were monitored for 40 months in these gaps and under closed forest. There were significant differences in survival and growth under closed forest between these three species. However, in gaps, the most important determinant of seedling survival and growth was seedling size at the time of gap creation, regardless of species. An ability to persist for long periods under closed forest and slowly accumulate growth may bestow an enormous size advantage on seedlings when gaps occur. Generalizations on the regeneration dynamics of dipterocarp rain forests need to be modified in the light of this result. Further observations for several years are important to see whether forest recovery eventually converges on predictions from the original paradigm.

Sign in / Sign up

Export Citation Format

Share Document