Biological Deterioration of Woods in Tropical Environments
Biological Deterioration of Woods in Tropical Environments

Author: Charles R. Southwell

Publisher:

Published: 1971

Total Pages: 68

ISBN-13:

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Six chemical wood preservatives were selected for evaluation over long periods of exposure in extremely borer-active marine environments. Southern Yellow Pine and Douglas Fir were full-cell pressure-treated with these chemicals and exposed in tropical seas and tropical brackish water for periods up to 90 months. Subsequently, 16 of the natural tropical woods considered best for use with pressure preservatives were combined with whole creosote and exposed in the most borer active of the seawater sites for periods exceeding 4 years. All samples have been removed, sectioned, and rated separately for the three major groups of marine borers: teredo, pholad, and limnoria. The long-term results show that heavy treatments of whole creosote and chromated copper arsenate (CCA, type A) are very effective preservatives for Southern Pine exposed in seawater, while the CCA was the singularly most effective treatment against the brackish-water Psiloteredo. Some of the most promising results were obtained with combinations of a few relatively limnoria-resistant tropical woods with a teredo-effective creosote pressure treatment. (Author).

Biological Deterioration of Wood in Tropical Environments. Part 2. Marine Borer Resistance of Natural Woods Over Long Periods of Immersion
Biological Deterioration of Wood in Tropical Environments. Part 2. Marine Borer Resistance of Natural Woods Over Long Periods of Immersion

Author: C. R. Southwell

Publisher:

Published: 1970

Total Pages: 47

ISBN-13:

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One hundred and fifteen wood species have been exposed to marine borers in three different tropical waters for periods up to 90 months. Underwater sites were in the Panama Canal Zone and included two oceans and a brackish-water lake. Over 30 species of marine-boring organisms were identified from these waters; their extreme activity in the warm tropical environments provided a very thorough screening test for the woods. Samples have been evaluated separately for resistance to the three principal borer classes--teredo, pholad, and limnoria. Several of the woods were resistant to one or more of the borer types. Some of these resistant species are relatively unknown as marine construction timbers, and in some instances they proved to be more durable than Greenheart, Teak, and other commercial marine woods. The species most resistant to all borers was Dalbergia retusa (Cocobolo), whose oily extract may provide leads to a satisfactory wood preservative. The woods most resistant to each of the different classes of borers are tabulated, with their respective silica content and density included. Silica was shown to be significant only in relation to teredine borers, while wood density was important only with pholads. Woods considered to be of special interest because of findings in the study are discussed individually. (Author).

Biological Deterioration of Woods in Tropical Environments
Biological Deterioration of Woods in Tropical Environments

Author: Charles R. Southwell

Publisher:

Published: 1973

Total Pages: 32

ISBN-13:

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The report describes the biodegradation of treated and untreated woods in the marine and terrestrial environments of the Panama Canal Zone. Presented are the final results of the terrestrial studies for exposure periods up to 13 years at three jungle exposure sites. One hundred fifteen natural woods and five wood preservatives are evaluated for resistance to subterranean termites and to above-ground and below-ground fungal decay. (Modified author abstract).

Natural Resistance of Woods to Biological Deterioration in Tropical Environments. Part I. Screening Tests of a Large Number of Wood Species
Natural Resistance of Woods to Biological Deterioration in Tropical Environments. Part I. Screening Tests of a Large Number of Wood Species

Author: C. R. Southwell

Publisher:

Published: 1962

Total Pages: 49

ISBN-13:

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In four different tropical environments, heavily infested with wood-destroying organisms, 114 species of scientifically identified woods have been undergoing a screening test for periods up to an 18-month exposure. Many of the woods were selected because of their reputed resistance to biological attack. Results of marine borer resistance studies have revealed 21 woods to be highly resistant to borers in Pacific Ocean water for the first 14 months of exposure. In tropical brackish water only 3 woods studied were highly resistant and very heavy damage was observed on 69 during the 14-month period. Stake tests in tropical jungle soil on both the Atlantic and Pacific Coasts of Panama showed 26 woods to be very durable to both subterranean termites and fungal decay for the first 18 months of exposure. A number of these resistant woods had not been studied previously. From the results of these studies, each wood included has been assigned resistance ratings of high, moderate, or low in respect to marine borer attack in sea water, teredo attack in brackish water, subterranean termites in tropical soil, and fungal decay in contact with jungle soil. Detailed descriptions of wood species which are considered to be of special interest are included. (Author).