Background: Selective logging alters tree growth, mortality and recruitment, and the subsequent population dynamics of trees. However, little information is available on how tree populations reduce local extinction in logged forests. Aims: We evaluated the effects of selective logging on tree performance and population dynamics of five dominant dipterocarp species in the Pasoh Forest Reserve, Malaysia. Methods: We used demographic data derived from a forest that was selectively logged in 1958 as well as those from an unlogged primary forest and constructed population transition matrix models to project the population dynamics. Results: The dipterocarp species studied showed minor differences in mortality and diameter growth, but there was a large difference in recruitment between logged and unlogged forest; populations in the logged forest had 10 times slower recruitment rates into the smallest size class than those in the primary forest. Population size structures differed between the two forest types but, despite a large difference in the recruitment rates, there were only minor differences in both asymptotic-and matrix-projected population growth rates. Conclusions: A single selective logging event had only minor impacts on the growth rates of dipterocarp trees in the Pasoh forest. But at the same time it had a large impact on the size structure of the dipterocarp populations through a reduction in recruitment showing that the impacts of selective logging are still seen on dipterocarp population after 50 years.

The human forearm with elbow joint has two degrees of freedom of motion. Especially it is noticed that the wide range for the rotation of the forearm (pronation-supination) is attained according to the sophisticated complexity of the human forearm with elbow joint. The elucidation of its movement mechanism is useful for the functional evaluation for the medical treatment and application to the welfare devices for the upper limb. The purpose of this study is to develop the arm model that functionally mimics the musculoskeletal system of the human forearm with elbow joint. In this paper, we made a physical model and the computational models, which replicate the bionic function of the forearm with elbow joint. By estimating the moment arms in a physical model, the mobility of the simplified physical model was evaluated. In the three-dimensional computational forearm bone models different in the geometry, the beneficial property of the centroidal lines of the bones was confirmed to extend the range of motion for the pronation-supination.

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The human elbow joint has two degrees of freedom ． Especially， widc range for the retation of the forearm ( pronation − supination ) is attained ， because of the sophjsticated complcxity of the human elbow joint ． The clucidation ofits mcchanism is useful for medical evaluation and application to wclfare devices ． Thc purpose ofthe stUdy is to develop thc arm model that imitatcs the musculo − skcletal system of human elbow joint ， In this paper， wc made a simplified physical model with a bionic elbow joint and evaluated thc mobility of the arm model by the moment arm ，

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