Tropical TImber

Timber knots recognition is of prime importance to further determine the timber grade. The recognition is normally based on the human expert's eyes in which can lead to some flaws based on human limitations and weaknesses. The use of X-ray can cause emits radiation and can be dangerous to the workers. This paper addresses the employment of computational methods for knot detection. A pre-processing and feature extraction methods include contrast stretching, median blur and thresholding, gray scale and local binary pattern were used. More than 400 datasets of knot images of the tropical timbers, namely Acacia and Hevea Brasiliensis have been tested using C-support vector machine as a knot classifier. The findings demonstrate different performances for three types of kernel. Linear kernel function outperformed both radial basis function and polynomial kernel functions for Acacia and Hevea Brasiliensis species. Both species classifications using linear kernel have managed to achieve a promising accuracy. Knots classification with the used of support vector machine has shown a promising result to improve the classifier and test with different types of tropical timbers.

Disclaimer: This study has been prepared by CATIE, as a request from ECOS, as an exploratory study on teak prices, contracted on the base of time worked and expertise. This report has been elaborated using only information available from reports and internet sites, is only valid for internal reference and only shows evidence. CATIE is not responsible for business and investment decisions made using data from this report.

In dieser Diplomarbeit soll anhand eines kleinen regionalen Beispieles die Problematik der "Regenwald-Zerstörung" untersucht werden. Dabei soll es nicht darum gehen, weitere Argumente für oder gegen die Vernichtung weiterer Regenwaldressourcen zu finden, sondern es wird versucht zu verstehen, was im Moment mit den Wäldern der südwestlichen Zentralafrikanischen Republik geschieht. Im Moment bezieht sich dabei auf einen relativ eng gesetzten Zeitraum, der sich auf Veränderungen innerhalb der ca. letzten dreißig Jahre bezieht. "Geschieht" soll von vornherein implizieren, daß der Wald natürlicherweise einer ständigen Eigendynamik unterliegt, andererseits aber auch stark durch exogene Einflüsse mitgestaltet wird. "Verstehen" meint hier, daß die postulierten rezenten Veränderungen in tropischen Regenwäldern mit geographischen Methoden erfasst und analysiert werden sollen, um eine Aussage über die räumliche Konfiguration von Landbedeckungsmustern machen zu können, die schlussendlich zu einer Beurteilung der aktuell wirkenden Gestaltungskräfte in den wechselfeuchten Tropen der Zentralafrikanischen Republik führen sollen.

Cedrela odorata (Spanish cedar) is a neotropical broadleaf tree species that is in high demand for furniture and interior fittings. In 1998, seed collections were made from Spanish cedar in the Yucatan Peninsula, Mexico, for genetic conservation and tree improvement projects. Progeny
from these collections were established in genetic trials at Bacalar, Noh Bec, and Zoh Laguna in the Yucatan. Survival at 2 years was 73.5% at Bacalar, 72% at Noh Bec, but only 20% after 6 months for several replicates at Zoh Laguna. Mean 2-year height, number of years of Hypsipyla attack on apical shoots (over 2 or 3 years) and total branching over 2 years, were 1.3 m, 0.04 years, and 2.5 branches at Bacalar, and 1.9 m, 0.35
years, and 1.6 branches at Noh Bec. Selection of the three best provenances (Esca´rcega, Bacalar, and Calakmul) would result in an estimated crosssite gain of 8.6% in 2-year height.Within-provenance, cross-site heritabilities for 2-year height, shoot borer attack, and branching were 0.1  0.02, 0.0  0.02, and 0.0  0.02, respectively. Single-site heritabilities for height at 2 years, shoot borer attack, and branching were 0.09  0.05,
0.02  0.04, and 0.09  0.05 at Bacalar and 0.16  0.07, 0.0  0.06, and 0.0  0.07 at Noh Bec. Given the known advantage of rapid growth to avoid Hypsipyla damage over the long term and the stable performance of provenances across sites for growth traits, we recommend provenance selection over multiple trials to reduce the risk of serious damage by the insect. Good provenances and other suitable seed sources, as well as proper site selection and silvicultural practices, are important tools for increasing yields from plantations of C. odorata.