In the Sierra de Guadalupe, Edo. de Mexico., Mexico, were planted Quercus rugosa Née seedlings of two qualities (small plant, with 8-15 cm in height and <2 mm in diameter, and large plant, with 16-24 cm in height and 2-4 mm in diameter), on two aspects (NE and SW), and in three microsite conditions (at NE and SW of rocks and a control without rock). The objective was to study the survival and growth one year after plantation. The experiment was analyzed using a mixed procedure. The three factors were significant, but not their interactions. The large plant had higher survival than the small plant (37 and 26%); the survival on NE aspect was higher than on SW aspect (45 and 16%); the seedlings with microsite showed higher values than the control (41% for NE, 32% for SW, and 20% for the control). The additive effect of the best levels in each factor (large plant, NE aspect and NE microsite) yielded a survival of 64%. The worst condition had 0% of survival (small plant, SW aspect, SW microsite).

The study evaluated the level of phenotypic variation in eight economically important traits, including wood volume, stem straightness and wood density, in a three-years old commercial plantation of melina (Gmelina arborea Linn., Roxb.), located in Escárcega, Campeche. The selection differential, after phenotypic selection of 20 superior trees in this base population, was obtained. Results showed that a wide phenotypic variation exists in the plantation, with a coefficient of variation over 20 % for six of the eight traits considered, except for wood density and stem straightness, where coefficient of variation was only 8.5 and 5.0 %, respectively. Due to this broad variation, a large selection differential was obtained for all growth traits (0.056 m3 for volume, 3.8 cm for height, 4.5 cm for diameter), indicating that substantial gain can be obtained by selecting these trees, even if these traits have low heritability values. Despite the low coefficient of variation for wood density and stem straightness, selection of the 20 phenotypically superior trees would allow to obtain a favorable response in wood quality.

Residual water that is generated in Durango City, is generated from domestic origin containing organic and solid pollutants, due to 490,524 citizens. This daily flow has generated the amount of 80,175 m3 as total volume of residual mud in six aeration lagoons. Forest planting programs in Durango have been increased lately with a main purpose; to recover the forest cover in the degraded areas in the forest. The National Forest Commission (CONAFOR) in Durango produced 12’910,410 plants during 2002, and 2’500,000 were Agavaceas. This involves the use of great amount of substrate to produce the goals; it increases the production costs. Residual mud are proposed to being as an alternative substrate, to reduce the cost for agaves plants demand, which it has increased due to the origin denomination NOM-070-SCF-1994, that has acquired the mescal drink in Durango, and to solve the residual mud problems in the residual lagoons. In an random design 3 treatment and 3 repetitions were tested: Treatment I.- Fresh Mud (88.184 pounds); II.- Fresh Mud (88.184 pounds) mixed with of alfalfa, (22.046 pounds) Dry oat straw (22.046 pounds) and fresh livestock manure (22.046 pounds); III.- agriculture soil from Institute Technologic Agropecuario Nº1. Measured variables were: total and fecal number of coliforme (coiffures); and before and after composted process; physic and chemical characteristics; and the main heavy metals. Once data were obtained, a statistic program from The Agronomy Faculty belong Nuevo Leon University (FAUNAL) was used. Significant statistical differences were obtained among treatments; 600 NMP ( more probable number) of fecal coiffures for treatment ll after composting; it is a low value as comp rated to the official standard allowed for public use who will being in direct contact (NOM 1987). Treatment ll result shows the composting effectiveness, due to the fact that residual mud act as an additional inoculums in the degradation of organic matter and fecal ciffures decay. According to the physical and chemical analysis results, the pH was 6.5, the fertility in treatment ll shows the higher nitrogen percentage 0.58 % and organic matter 11.62%. The heavy metals values in treatment ll, are statistically lower compared to treatment l were pure composted residual mud were used. According to the Protecting Environmental Agency of The United States of EPA , these values are below the maximum allowed limits.

The study was done in a plantation located in a serpentine savanna of Camagüey province, located in an area of Las Cuabas site belonging to Camagüey silvicultural Unit of the Camagüey Integral Forestry Enterprise. A mathematical model was developed from this work taking into account a sample of 211 Casuarina equisetifolia Forst. trees, which allow to determinate the normal diameter (d) from the stump diameter with the use of 99 values for the regression analysis and 112 to do the validation of the equation. Data emerged from 10 temporal stands of 500 m2 sample plots; they were processed using regression procedures. The logarithmic equation selected to the construction of table, estimates the values with great precision. Ln d = - 0.249 + 1.021 ´ Ln dtoc ± 0.07306

This study was developed in the Integral Forest Enterprise “La Palma”, province Pinar del Río, Cuba. The objective was to evaluate the effect of the prescribed burns in soil properties of Pinus tropicalis forests in Cuba. Four parcels of 1,000 m2 were located. One was the control and in the remaining it was applied prescribed burn. In each one of these parcels were distribute of aleatory form five sampling points. One week before applying the prescribed burn and one week after the same one, in each point they took soil samples to depths from 0 to 10 cm and of 10 to 20 cm. The data were analyzed through the tests of statistic average (ANOVA). The results show a light rise (but it doesn’t have any significance) for de pH, the P2O5 (exchanged phosphorus), el Mg+ y el K+ (assimilable potassium) after a year of burning. By the other hand, there were little decreeses in K2O (exchanged), organic matter and Ca+, after a year of burnings, while the content of Na+ increases significatively, decreasing significatively the hydrolytic acidity and the capacity of cationic change for to the two depths before and after burning. The relation among soil nutrients are found in the typical parameters of these poor soils.

Was determined the nutritional requirements of Sweitenia macrophylla and Cupressus lusitanica in two soils Inceptisol and Ultisol the North Region of Costa Rica in a test of greenhouse using one technique that involves: a) preliminary analysis of the original sample, b) Studies of Sorción, c) Techniques of greenhouse. There was significant difference among the treatments with height in the Inceptisol, for S. macrophylla and C. lusitanica what indicates that there is answer to the application of additional fertilizer in the field. For the Inceptisol the requirements for S. macrophylla in order according to the tests gives greenhouse they were: P> Cu> B> Fe> N. For the C. lusitanica they were: P> K> Mn> Cu> Zn> Fe. For the Ultisol the nutritional requirements for S. macrophylla were: B> Fe> Mn> Zn> N> P> K> Cu. It is important to consider that they are the microelements those that have bigger answer to the application, with the variables of growth the biggest securities they were obtained in order K> N> P. And C. lusitanica were: N > P > Mn > Fe > Zn. With the variables of growth the biggest securities they were obtained in order K > N > P.

The pressing process defines the quality of plywood through the interrelation of the technological properties of wood, the adhesive characteristics, and the interaction of temperature and pressure generated in the hot press. This study was carried out in order to analyze the effect of heat transfer on the polymerization of adhesives formulated with urea and phenol formaldehyde and to optimize the pressing schedules of 6, 9, 12, 15, 18 and 34 mm plywood thickness, as well as to evaluate the compaction of boards as a result of temperature and pressure during the hot pressing cycle. Veneer of Pinus herrerai Martínez, P. michoacana Martínez, and P. pseudostrobus Lindl. at a moisture content of 6 to 8 % was used as well as a press heated with steam and urea formaldehyde, to produce boards 6, 9, 12, 15 and 18 mm thick, and phenol formaldehyde for the 34 mm plywood. Pressing cycles with temperature of 115, 130 and 140 °C and pressures of 10.62 kg·cm-2 (151 psi) and 8.51 kg·cm-2 (121 psi) were analyzed for interior use, and for exterior type boards temperatures of 140, 150 and 160 °C and pressures of 12.23, 13.29 y 14.34 kg·cm-2 (174, 189 y 204 psi) were also evaluated. The temperature of the outermost glue lines increases rapidly with the closing of the press, maintaining a difference with the innermost glue line, which tends to disappear with the pressing time, becoming similar at 73 % of pressing time for each type of board. It was determined, through the evaluation of the adhesive characteristics of the interior type glue with the PS1-95 standard, that all boards fulfill the specifications for that type of application. In the 34 mm thickness boards, the temperature was raised from 140 to 160 °C, the pressure from 12.23 to 14.34 kg·cm-2 (174 a 204 psi) and the phenol formaldehyde solid content from 29.9 to 32 %, as a result, a reduction on pressing time by 28.6 % (35 to 25 min) and 1.8 % in compaction were achieved; furthermore the delamination problems of these type of boards were eliminated.

The University of Pinar del Río financed a project of Investigation for the study of the chemical composition of species of fast growth with the purpose of obtaining scientific data for the possible industrial advantage thus studied the wood of Eucalyptus pellita F. Muell, to three heights of the commercial bole. The samples coming from the Forestry Company of Macurijes, in the province of Pinar del Río, Cuba, were determined the extractives substances, the percentage contents of the components of the cellular wall, and the mineral substances, using TAPPI Norms. The cellulose was studied by Differential Scanning Calorimetric (DSC) and the lignin was studied by means of IR spectroscopy, the data demonstrated differences in the contents of soluble substances in ethanol after toluene-ethanol, water and the components of the cellular wall. The band of 1500 cm-1 in the IR spectroscopy reflected the presence of kinos (phenolic compound derivate by secondary metabolism of plants) residual in the lignin. The thermal behavior of the cellulose sample differences with the height of the commercial bole attributed to variations with the crystallinity and polymerization degree, demonstrating a behavior similar to other species of Eucalyptus of this same region.

The Chemical composition of wood from Corymbia citriodora was studied at three different heights of commercial bole. The samples were obtained from the Macurije zone in the Pinar del Río province. Cellulose, lignin, hemicelluloses, ash content, as well as the extractive substances in different solvent systems were studied according to TAPPI Standard Norms. Cellulose was studied by means of Differential Scanning Calorimetry, and lignin by Infrared Spectroscopy. The extractive substances and lignin content decreased with the height of commercial bole. Infrared results suggest the presence of syringyl -guaiacyl lignins, and structural differences in the different parts of the tree. IR signal in 1500 cm–1 explains, the variation of lignin content according to the height of tree. These results suggest that the lignin in the upper part of a tree is less cross linked and has a lower degree of polymerization. The thermal behaviour of wood cellulose showed sharp peaks and higher enthalpy variations with the height of commercial bole. The results showed that the chemical composition and structural characteristic of cellulose and lignin vary to height of the tree.

In order to evaluate the effect of three factors on the survival and growth of Pinus cooperi Blanco seedlings, a study was conducted in the nursery of the Experimental Research Station “Valle del Guadiana-INIFAP”, Durango, Dgo., Mexico. Treatments were distribuited according to split-split plot experimental design. The variables evaluated were: a) two container sizes: 80 y 170 cm3 of total volume, b) three fertilization routines with different nitrogen (N), phosphorus (P) and potassium (K) doses, according to the three seedling growth phases, and c) three irrigation frequencies: every 48, 96 and 168 hours in the hardening phase. After eight months of seedling growth, it was found that containers with a volume of 170 cm3 had a significant effect on plant growth. The fertilization routines did not have significant differences in any of the measured variables. Finally, the irrigation schedules during hardening phase, enhanced height and diameter growth and phytomass productivity when irrigated every 48 hours. Survival was not controlled by any of the studied sources of variation.