Differences in Survival and Growth Among Tropical Rain Forest Pioneer Tree Seedlings in Relation to Canopy Openness and Herbivory

Biotropica ◽  
2014 ◽  
Vol 46 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Uromi M. Goodale ◽  
Graeme P. Berlyn ◽  
Timothy G. Gregoire ◽  
Kushan U. Tennakoon ◽  
Mark S. Ashton
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Canopy Openness ◽  
Tree Seedlings ◽  
Pioneer Tree ◽  
Survival And Growth

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.

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.

Understorey light environments in a north-east Australian rain forest before and after a tropical cyclone

1992 ◽  
Vol 8 (3) ◽  
pp. 241-252 ◽  
Author(s):  
S. M. Turton
Keyword(s):  
Tropical Cyclone ◽  
Rain Forest ◽  
Light Availability ◽  
Fold Increase ◽  
Canopy Openness ◽  
Tree Seedlings ◽  
Site Factors ◽  
North East ◽  
Canopy Disturbance ◽  
Before And After

ABSTRACTThis paper describes estimates of canopy openness and associated light availability in the understorey of a north-east Australian rain forest before and immediately after a tropical cyclone. On the basis of 20 hemispherical (fisheye) canopy photographs it was shown that direct, diffuse and total site factors increased significantly as a result of the slight-to-moderate canopy disturbance caused by the cyclone. In the understorey, median total site factors ranged from 2.5–3.4% before the cyclone and from 6.0–8.6% after the cyclone, representing a 2- to 3-fold increase in potential light availability. Following the cyclone, mean relative gap frequencies increased substantially at all altitudes but particularly at canopy positions more than 70° above the horizon. Cyclone-induced canopy disturbance not only reduced the complexity of the understorey light regime but may have also increased the seasonal variability of light within the understorey of the forest during the interval of canopy recovery. The implications of these results for the ecophysiology of understorey tree seedlings and saplings at several temporal scales are discussed.

Herbivory of tropical rain forest tree seedlings correlates with future mortality

Ecology ◽  
2010 ◽  
Vol 91 (4) ◽  
pp. 1092-1101 ◽  
Author(s):  
Markus P. Eichhorn ◽  
Reuben Nilus ◽  
Stephen G. Compton ◽  
Sue E. Hartley ◽  
David F. R. P. Burslem
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Forest Tree ◽  
Tree Seedlings

Use of hemispherical photographs in forest ecology: measurement of gap size and radiation totals in a Bornean tropical rain forest

1993 ◽  
Vol 9 (2) ◽  
pp. 131-151 ◽  
Author(s):  
T. C. Whitmore ◽  
N. D. Brown ◽  
M. D. Swaine ◽  
D. Kennedy ◽  
C. I. Goodwin-Bailey ◽  
...  
Keyword(s):  
Forest Dynamics ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Forest Ecology ◽  
Canopy Openness ◽  
Gap Size ◽  
Active Radiation ◽  
Cloudy Weather ◽  
Hemispherical Photographs

ABSTRACTStudy of forest dynamics commonly requires measurement of canopy gap size. Hemispherical photographs can be analysed to provide various measures whereby gaps can be ranked in order of size. For ten artificial gaps in a Bornean tropical rain forest these measures were better correlated with gap microclimate than gap area measured physically on the ground. All these measures are however relative. For detailed (e.g. ecophysiological) studies the greater detail provided by absolute measures of photosynthetically active radiation (PAR) are required. Long term PAR values can be computed from hemiphots so long as measurements in the open nearby are available. Correction for cloudy weather is essential. Computed and measured PAR are compared for the test gaps. Both have inherent limits which means that below c. 15% canopy openness, differences in PAR between gaps cannot be assessed accurately.

scholarly journals Neighbourhood composition determines growth, architecture and herbivory in tropical rain forest tree seedlings

2006 ◽  
Vol 94 (3) ◽  
pp. 646-655 ◽  
Author(s):  
FERGUS P. MASSEY ◽  
KATE MASSEY ◽  
MALCOLM C. PRESS ◽  
SUE E. HARTLEY
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Forest Tree ◽  
Tree Seedlings
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