Determinants of spatial patterns of canopy tree species in a tropical evergreen forest in Gabon

The effects of disturbance regimes on the spatial patterns of the five most abundant species were investigated in three sites in a tropical forest at Xuan Nha Nature Reserve, Vietnam. Three permanent one-ha plots were established in undisturbed forest (UDF), lightly disturbed forest (LDF), and highly disturbed forest (HDF). All trees ≥5 cm DBH were measured in twenty-five 20 m × 20 m subplots. A total of 57 tree species belonging to 26 families were identified in the three forest types. The UDF had the highest basal area (30 m2 ha−1), followed by the LDF (17 m2 ha−1) and the HDF (13.0 m2 ha−1). The UDF also had the highest tree density (751 individuals ha−1) while the HDF held the lowest (478 individuals ha−1). Across all species, there were 417 “juveniles,” 267 “subadults,” and 67 “adults” in the UDF, while 274 “juveniles,” 230 “subadults,” and 36 “adults” were recorded in the LDF. 238 “juveniles,” 227 “subadults,” and 13 “adults” were obtained in the HDF. The univariate and bivariate data with pair- and mark-correlation functions of intra- and interspecific interactions of the five most abundant species changed in the three forest types. Most species indicated clumping or regular distributions at small scale, but a high ratio of negative interspecific small-scale associations was recorded in both the LDF and HDF sites. These were, however, rare in the UDF.

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Using spatial patterns of seeds and saplings to assess the prevalence of heterospecific replacements among cloud forest canopy tree species

Journal of Vegetation Science ◽

10.1111/jvs.13083 ◽

2021 ◽

Author(s):

Nancy R. Mejía‐Domínguez ◽

Jorge A. Meave ◽

Carlos Díaz‐Ávalos ◽

Lorena Gómez‐Aparicio

Keyword(s):

Spatial Patterns ◽

Tree Species ◽

Forest Canopy ◽

Cloud Forest ◽

Canopy Tree ◽

Canopy Tree Species

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Vegetation and gap dynamics of a tropical wet evergreen forest in the Western Ghats of Kerala, India

Journal of Tropical Ecology ◽

10.1017/s0266467400008014 ◽

1994 ◽

Vol 10 (3) ◽

pp. 337-354 ◽

Cited By ~ 34

Author(s):

U. M. Chandrashekara ◽

P. S. Ramakrishnan

Keyword(s):

Tree Species ◽

Western Ghats ◽

Monsoon Season ◽

Mixed Forest ◽

Canopy Gap ◽

Evergreen Forest ◽

Gap Formation ◽

Canopy Tree ◽

Canopy Tree Species ◽

The Western Ghats

ABSTRACTThe wet evergreen forest of Nelliampathy in the Western Ghats of Kerala in India is a mixed forest with a high species diversity and basal cover. In this relatively undisturbed ecosystem, canopy gaps are largely formed through single tree fall, but gaps through branch fall, crown fall, standing dead trees or multiple tree fall also occur. Canopy gap formation is more (over 82% of the total gaps created) during the monsoon season. The mean number of gaps formed in this forest is 1.13 ha−1 y−1 and the turnover rate is 83 years. The majority of the gaps created (over 70%) are of smaller size (≥ 100 m2). In this forest, while some top canopy tree species (those capable of exceeding 25 m in height at maturity) such as Palaquium ellipticum and Mesua nagassarium are well represented in seedling, sapling and mature tree stages, others like Aglaia exstipulata and Mastixia arborea are observed only as saplings and/or mature trees with no seedling populations. The possible reasons for these two types of regeneration behaviour by top canopy tree species in the context of canopy gap size and seasonality in gap formation are discussed.

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