Lyptus

Abstract: Plantations of Eucalpytus saligna Sm. grow rapidly in Hawaii, but supple­ mental nitrogen (N) is required on many sites. Because of the high cost of synthetic N fertilizer, mixed species plantings in which N is added by Albizia falcataria (L.) Fosb., an N 2 -fixing tree, are being tested on the island of Hawaii. Five combinations of Euca­ lyptus and Albizia were compared with each other, with pure Albizia, and with pure Eucalyptus fertilized periodically with nitrogen. The test is a randomized block design with four replications on the wet, Hamakua coast. At 48 months, Eucalyptus trees in the mixed plantings containing 34% or more Albizia were equal to or larger than those in the pure, fertilized stands. Total dry yields ranged from 109 ton/ha in pure Albizia plantings to 67 tonlha in mixed species plantings with only 11% Albizia. Yields in the mixed plantings with 34 to 66% Albizia were 103 to 105 ton/ha, whereas yield in the pure, fert ilized Eucalyptus stand was 94 ton/ha. Nitrogen concentration of Eucalyptus foliage increased as the amount of Albizia increased in the stand; and in mixed plantings with 34% or more Albizia, foliar N concentration exceeded that of the pure, fertilized, Euca­ lyptus treatment. Phosphorus levels in Eucalyptus foliage similarly increased as amounts of Albizia increased in the stand. At 48 months, total N was higher in soils of mixed species and pure Albizia plantings than in soils of the pure, fertilized Eucalyptus treat­ ment. Albizia can provide the N needed by Eucalyptus in high-yielding bioenergy plan­ tations along the Hamakua coast. FOR. SCI. 35(1):64-75.

Abstract: PROBLEM TO BE SOLVED: To provide a process for producing clone seedlings of plants in Euca lyptus where the whole of the process steps can be operated under the nonaseptic conditions. SOLUTION: The objective process for producing clone seedlings of plants in Eucalyptus characteristically comprises the following process steps: 1) The apical bud of a seedling of a Eucalyptus plant is cut off and the auxiliary buds are grown to prepare a multibudded seedling; 2) A plurality of shoots are collected by cutting; 3) The shoots are transplanted to the rooting culture medium for rooting; 4) The rooted shoots are acclimated whereby the objective clone seedlings are grown.

Abstract: Wood is a renewable source of structural material with high relative strength/weight, low energy production, which kidnaps and stores carbon in its production The large use of wood is due to its special qualities as raw material for other products manufactured in residential construction or major works such as bridges, has been widely used in roofing for industrial and commercial buildings Commercially there are limitations on the length of the wood, resulting from the extraction of tree trunks, thus requiring the adoption of binding elements is the use of self-tapping screws efforts required by side and which can be axial, shear, tensile or compression Whereas in Brazil does not yet exist and the promising future of the product, this research aims to study the behavior of self-tapping screws together with Brazilian reforestation species of Pinus oocarpa and Lyptus (softwood and hardwood) Rothoblaas self-tapping screws had a good penetration in both woods without requiring pre-drilling, the species of Lyptus wood showed the highest values of strength and the inclination of the screws, at 45 degrees showed the best results on either species of wood

Abstract: Since it was introduced in Madagascar, Euca- lyptus robusta has been considered as a suit- able species for reforestation thanks to its outstanding ecological adaptability. With fur- ther plantings in rural communities, the species now covers some 140 000 hectares around Antananarivo. Its timber has become the main source of fuel for urban and rural households in Madagascar. Today, however, the sustainability of this resource is under severe threat. The market deficit coupled with rural poverty is causing forest owners to shorten their coppicing cycles, sometimes to as little as 2 years. This over-exploitation is depleting soil minerals that are not being replaced by nutrient inputs. Traditional char- coal production has continued, using earth mounds where the potential yield by weight is only about 10%. Applying simple methods to double the yield would substantially reduce the forest area logged each year for charcoal. At 6 years of age, the annual incre- ment in commercial timber from older cop- pices is about 18.8 m3/ha/year. The best recently imported provenances are doubling the average individual volume of 9 year-old trees. Seed orchards have been planted with several provenances from the natural range of the species to create composite varieties. However, the quality of the varieties pro- duced is significantly affected by preferen- tially intra-provenance fertilisation and exter- nal pollen. In extending the planted area, rural populations have continued to use local seeds or to plant seedlings found in old plan- tations. These E. robusta plantations should continue to produce wood despite the biotic and abiotic changes already observed in Madagascar. To cope with these changes, modern technologies can help forest researchers to develop a sustainable fuel- wood production system around large urban centres. This would maintain regular incomes to enable rural populations to survive.