scholarly journals Impending Regeneration Failure of the Iucn Vulnerable Borneo Ironwood (Eusideroxylon Zwageri)

2018 ◽  
Author(s):  
Lan Qie ◽  
Alexander D. Elsy ◽  
Ashley Stumvoll ◽  
Magdalena Kwasnicka ◽  
Anna L. Peel ◽  
...  
Keyword(s):  
Tree Species ◽  
Ecological Processes ◽  
Regeneration Failure ◽  
Climax Species ◽  
Tropical Tree Species ◽  
Tree Population ◽  
Local Aggregation ◽  
High Level ◽  
Combined Impact ◽  
Eusideroxylon Zwageri

AbstractThe regeneration of many climax species in tropical forest critically depends on adequate seed dispersal and seedling establishment. Here we report the decreased abundance and increased spatial aggregation of younger trees of the Borneo ironwood (Eusideroxylon zwageri) in a protected forest in Sabah Malaysia. We observed a high level of seedling herbivory with strong density dependence, likely exacerbated by local aggregation and contributing to the progressively shrinking size-distribution. We also note the largely undocumented selective herbivory by sambar deer on E. zwageri seedlings. This study highlights the combined impact of altered megafauna community on a tree population through interlinked ecological processes and the need for targeted conservation intervention for this iconic tropical tree species.

scholarly journals Impending Regeneration Failure of the IUCN Vulnerable Borneo Ironwood (Eusideroxylon zwageri)

2019 ◽  
Vol 12 ◽  
pp. 194008291882335 ◽  
Author(s):  
Lan Qie ◽  
Alexander D. Elsy ◽  
Ashley Stumvoll ◽  
Magdalena Kwasnicka ◽  
Anna L. Peel ◽  
...  
Keyword(s):  
Tree Species ◽  
Ecological Processes ◽  
Regeneration Failure ◽  
Climax Species ◽  
Tropical Tree Species ◽  
Tree Population ◽  
Local Aggregation ◽  
High Level ◽  
Combined Impact ◽  
Eusideroxylon Zwageri

The regeneration of many climax species in tropical forest critically depends on adequate seed dispersal and seedling establishment. Here, we report the decreased abundance and increased spatial aggregation of younger trees of the Borneo ironwood ( Eusideroxylon zwageri) in a protected forest in Sabah Malaysia. We observed a high level of seedling herbivory with strong density dependence, likely exacerbated by local aggregation and contributing to the progressively shrinking size distribution. We also note the largely undocumented selective herbivory by sambar deer on E. zwageri seedlings. This study highlights the combined impact of altered megafauna community on a tree population through interlinked ecological processes and the need for targeted conservation intervention for this iconic tropical tree species.

scholarly journals Gene flow and mating system of the tropical tree Sextonia rubra

2005 ◽  
Vol 54 (1-6) ◽  
pp. 275-280 ◽  
Author(s):  
V. Veron ◽  
H. Caron ◽  
B. Degen
Keyword(s):  
Gene Flow ◽  
Mating System ◽  
Tree Species ◽  
Pollen Dispersal ◽  
Joint Estimation ◽  
Tropical Tree ◽  
Effective Density ◽  
Mixed Mating ◽  
Tropical Tree Species ◽  
High Level

Abstract In this paper we report a study of the mating system and gene flow of Sextonia rubra, a hermaphroditic, insect pollinated tropical tree species with a geographic distribution in the Guyana Plateau and the Amazon. Using five microsatellites we analysed 428 seeds of 27 open pollinated families at the experimental site “Paracou” in French Guiana. We observed, compared to other tropical tree species, a high level of genetic diversity. We estimated parameters of the mating system and gene flow by using the mixed mating model and the TwoGener approach. The estimated multilocus outcrossing rate, tm, was 0.992 indicating nearly complete outcrossing. A significant level of biparental inbreeding and a small proportion of full-sibs were estimated for the 27 seed arrays. The differentiation of allelic frequencies among the pollen pools was ΦFT = 0.061. We estimated mean pollen dispersal distances between 65 m and 89 m according to the dispersal models used. The joint estimation of pollen dispersal and density of reproductive trees gave an effective density estimate of 2.1-2.2 trees/ha.

scholarly journals Loss of animal seed dispersal increases extinction risk in a tropical tree species due to pervasive negative density dependence across life stages

2015 ◽  
Vol 282 (1798) ◽  
pp. 20142095 ◽  
Author(s):  
T. Trevor Caughlin ◽  
Jake M. Ferguson ◽  
Jeremy W. Lichstein ◽  
Pieter A. Zuidema ◽  
Sarayudh Bunyavejchewin ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Density Dependence ◽  
Tropical Forests ◽  
Tree Species ◽  
Population Viability ◽  
Spatial Aggregation ◽  
Life Stages ◽  
Tropical Tree Species ◽  
Tree Population ◽  
Negative Density Dependence

Overhunting in tropical forests reduces populations of vertebrate seed dispersers. If reduced seed dispersal has a negative impact on tree population viability, overhunting could lead to altered forest structure and dynamics, including decreased biodiversity. However, empirical data showing decreased animal-dispersed tree abundance in overhunted forests contradict demographic models which predict minimal sensitivity of tree population growth rate to early life stages. One resolution to this discrepancy is that seed dispersal determines spatial aggregation, which could have demographic consequences for all life stages. We tested the impact of dispersal loss on population viability of a tropical tree species, Miliusa horsfieldii, currently dispersed by an intact community of large mammals in a Thai forest. We evaluated the effect of spatial aggregation for all tree life stages, from seeds to adult trees, and constructed simulation models to compare population viability with and without animal-mediated seed dispersal. In simulated populations, disperser loss increased spatial aggregation by fourfold, leading to increased negative density dependence across the life cycle and a 10-fold increase in the probability of extinction. Given that the majority of tree species in tropical forests are animal-dispersed, overhunting will potentially result in forests that are fundamentally different from those existing now.

Development and characterization of 15 microsatellite loci for Cariniana estrellensis and transferability to Cariniana legalis, two endangered tropical tree species

2008 ◽  
Vol 10 (4) ◽  
pp. 1001-1004 ◽  
Author(s):  
Marcela Corbo Guidugli ◽  
Tatiana de Campos ◽  
Adna Cristina Barbosa de Sousa ◽  
Juliana Massimino Feres ◽  
Alexandre Magno Sebbenn ◽  
...  
Keyword(s):  
Microsatellite Loci ◽  
Tree Species ◽  
Tropical Tree ◽  
Tropical Tree Species ◽  
Cariniana Legalis

scholarly journals Large differences in leaf cuticle conductance and its temperature response among 24 tropical tree species from across a rainfall gradient

2021 ◽  
Author(s):  
Martijn Slot ◽  
Tantawat Nardwattanawong ◽  
Georgia G. Hernández ◽  
Amauri Bueno ◽  
Markus Riederer ◽  
...  
Keyword(s):  
Tree Species ◽  
Temperature Response ◽  
Tropical Tree ◽  
Rainfall Gradient ◽  
Tropical Tree Species ◽  
Leaf Cuticle

scholarly journals Diurnal and seasonal carbon balance of four tropical tree species differing in successional status

2008 ◽  
Vol 68 (4) ◽  
pp. 781-793 ◽  
Author(s):  
GM. Souza ◽  
RV. Ribeiro ◽  
AM. Sato ◽  
MS. Oliveira
Keyword(s):  
Functional Groups ◽  
Tree Species ◽  
Carbon Balance ◽  
Dark Respiration ◽  
Tropical Tree ◽  
Pioneer Species ◽  
Wet Season ◽  
Gross Photosynthesis ◽  
Tropical Tree Species ◽  
Successional Species

This study addressed some questions about how a suitable leaf carbon balance can be attained for different functional groups of tropical tree species under contrasting forest light environments. The study was carried out in a fragment of semi-deciduous seasonal forest in Narandiba county, São Paulo Estate, Brazil. 10-month-old seedlings of four tropical tree species, Bauhinia forficata Link (Caesalpinioideae) and Guazuma ulmifolia Lam. (Sterculiaceae) as light-demanding pioneer species, and Hymenaea courbaril L. (Caesalpinioideae) and Esenbeckia leiocarpa Engl. (Rutaceae) as late successional species, were grown under gap and understorey conditions. Diurnal courses of net photosynthesis (Pn) and transpiration were recorded with an open system portable infrared gas analyzer in two different seasons. Dark respiration and photorespiration were also evaluated in the same leaves used for Pn measurements after dark adaptation. Our results showed that diurnal-integrated dark respiration (Rdi) of late successional species were similar to pioneer species. On the other hand, photorespiration rates were often higher in pioneer than in late successional species in the gap. However, the relative contribution of these parameters to leaf carbon balance was similar in all species in both environmental conditions. Considering diurnal-integrated values, gross photosynthesis (Pgi) was dramatically higher in gap than in understorey, regardless of species. In both evaluated months, there were no differences among species of different functional groups under shade conditions. The same was observed in May (dry season) under gap conditions. In such light environment, pioneers were distinguished from late successional species in November (wet season), showing that ecophysiological performance can have a straightforward relation to seasonality.

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