Potencialidad de varias especies para la obtención de biomasa con fines energéticos en el secano mediterráneo de Chile

In Chile, there are about 1.8 million hectares of dryland soils with severe site restrictions for agronomicand forest species growth. However, these soils can be used to establish energy crops, using forest species specially adapted to this condition. The purpose of this paper is to estimate the potential land availability in the drylands of central Chile for establishing short rotation forestry crops, with low water consumption species. The species Acacia saligna, Atriplex nummularia, Robinia pseudoacacia, Eucalyptus rudis, Eucalyptus globulus subspecies biscotata, Eucalyptus camaldulensis and Eucalyptus occidentalis, based on characteristics such as dry biomass yield, water requirements, tolerance to frost and calorimetric properties, were evaluated. The study area corresponds to Mediterranean drylands of Maule Region in Chile, with a total area of 544 thousand hectares. The results indicate that the potential for the seven crop species considered is about 100,000 ha. It can be concluded that thousands of land hectares are potentially available for growing short rotation forestry crops in the Mediterranean drylands of central Chile.En Chile existen aproximadamente 1,8 millones de hectáreas de suelos considerados de secano, con severas restricciones de sitio para el crecimiento de especies agrícolas y forestales. Sin embargo, dichos suelos, pueden ser utilizados y existe un potencial para establecer cultivos energéticos empleando especies forestales especialmente adaptadas a esta condición. El propósito de este trabajo es estimar la superficie potencial para establecer plantaciones energéticas de corta rotación, con especies forestales de bajos requerimientos hídricos, en el secano mediterráneo de la zona central de Chile. Se utilizaron las especies Acacia saligna, Atriplex nummularia, Robinia pseudoacacia, Eucalyptus rudis, Eucalyptus camaldulensis, Eucalyptus occidentalis y Eucalyptus globulus subespecie biscotata, en base a características como rendimiento de biomasa en secano, requerimientos hídricos, tolerancia a heladas y propiedades calorimétricas. El área de estudio corresponde al secano mediterráneo de la Región del Maule en Chile, con una superficie total de 544 mil hectáreas. Los resultados indican que el potencial de cultivo para las siete especies consideradas es de aproximadamente 100.000 ha. Se concluye que el secano mediterráneo de la Región del Maule en Chile presenta condiciones favorables para el establecimiento y desarrollo de plantaciones energéticas con cultivos de corta rotación

Growth of radiata pine families in nursery and two years after field establishment

Pinus radiata D. Don is the most widely planted exotic species in Australia, Chile, New Zealand and Spain. In this study, growth and survival of P. radiata were compared in 30 open pollinated families grown under two contrasting watering regimes in nursery (well-watered cf. water-stress conditions) and planted on a drought-prone site with Mediterranean climate in central Chile. This study assessed phenotypic plasticity in growth and survival at nursery stage and two years after establishment in the field. Family plasticity at nursery stage was estimated by the angular phenotypic change index (APCI), while the relationship between nursery and field traits was estimated by genetic correlations (rg ) and the Pearson coefficient of correlation (rxy). Families presented high plasticity in diameter, height, and survival at nursery stage. Out of 30 families, eight exhibited over 80 % survival in the well-watered treatment, but less than 20 % survival in the water-stress treatment. As expected, growth traits and survival were positively correlated (rg and rxy > 0.65) between both nursery environments. However, for growth, most genetic and phenotypic correlations between combinations of nursery treatments versus the field test were negative or not significant. As there was no detectable pattern of nursery–field correlations regarding to combinations of nursery treatments and test site, the need to include more stable families and genotypes to an appropriate developmental stage at nursery is discussed

Effect of indolebutyric acid, bottom heat, substrate, and parent tree on rooting capacity of Nothofagus glauca (Phil.) Krasser stem cuttings Efecto del ácido indolbutírico, del tipo de la cama de arraigamiento, del substrato, y del árbol madre en la capac

Nothofagus glauca (Phil.) Krasser is a tree of conservation concern that is characteristic for the mesomorphic zone of Chile. Techniques for vegetative propagation of this species are not well known. In this study, the rooting capacity of stem cuttings was investigated. Using vegetative material collected in November 1995 and 1997, the effect of indolebutyric acid (IBA = 0, 0.5, 1, and 2 %), bed rooting system (bottom heating and without temperature control), substrate (sawdust and bark compost of Pinus radiata D. Don), and parent tree on rhizogenesis was analyzed. Experiments were conducted for 2.5-4 months in a greenhouse. The greenhouse was equipped with an automatic misting system and bottom heating that maintained a temperature of 21-25°C at the stem base. Results indicate that N. glauca can be propagated from stem cuttings collected from root sprouts in November. Rooting capacity increased with IBA concentrations up to 1 % (88 % of the stem cuttings presented rooting), and decre

Risk management as a tool for the conservation of the forests of nothofagus alessandrii, an endangered species of central Chile GestiÓn de riesgo como herramienta para la conservaciÓn de los bosques de nothofagus alessandrii, una especie en peligro de ext

Climate change is a global threat affecting diverse forest formations, with the consequent loss of ecosystem services and quality of life of the inhabitants. Given the recurrent presence of natural disasters, having policies to deal with their consequences is desirable, risk management being a tool to such effects. In the face of climate change threats over the loss of ecosystem services, this paper aims to analyze the available information and research needs and priorities in order to be prepared and trained to mitigate the effects of fragmentation and loss of forests of Nothofagus alessandrii Espinosa (Ruil), an endangered and highly inbred species. To achieve the conservation of the remaining forests and the genetic resources of this species, a risk management program is proposed in three areas: 1) territorial planning for fire reduction and propagation, 2) increased knowledge about factors that shape the genetic and adaptive diversity of the species, and some aspects of its reprod

Risk management as a tool for the conservation of the forests of Nothofagus Alessandrii, an endangered species of central Chile

El cambio climático es una amenaza global que está afectando diversas formaciones boscosas, con la consiguiente pérdida de servicios ecosistémicos y perjuicio en la calidad de vida de los habitantes. Ante la presencia recurrente de desastres naturales, es deseable contar con políticas para enfrentar las consecuencias de ello, siendo la gestión de riesgo una herramienta para tales efectos. Ante la amenaza que significa el cambio climático en la pérdida de servicios ecosistémicos, en este trabajo se analiza la información disponible y las necesidades y prioridades de investigación para de estar preparados y capacitados para mitigar los efectos de la pérdida y fragmentación de los bosques de Nothofagus alessandrii Espinosa (ruil), una especie en peligro de extinción y con altos niveles de endogamia. A fin de lograr la conservación de los bosques remanentes y los recursos genéticos de esta especie, se propone una gestión de riesgo en tres áreas: 1) planificación territorial a fin de reducir la ocurrencia y propagación de incendios forestales, 2) incremento del conocimiento sobre los factores que moldean la diversidad genética y adaptativa de la especie, y algunos aspectos de su biología reproductiva y 3) evaluación más detallada de los actuales niveles de diversidad y diferenciación genética de las poblaciones de ruil. El conocimiento de estos y otros factores permitiría gestionar y anticiparse a las amenazas que podría experimentar la especie en el futuro.Climate change is a global threat affecting diverse forest formations, with the consequent loss of ecosystem services and quality of life of the inhabitants. Given the recurrent presence of natural disasters, having policies to deal with their consequences is desirable, risk management being a tool to such effects. In the face of climate change threats over the loss of ecosystem services, this paper aims to analyze the available information and research needs and priorities in order to be prepared and trained to mitigate the effects of fragmentation and loss of forests of Nothofagus alessandrii Espinosa (Ruil), an en-dangered and highly inbred species. To achieve the conservation of the remaining forests and the genetic resources of this species, a risk management program is proposed in three areas: 1) territorial planning for fire reduction and propagation, 2) increased knowledge about factors that shape the genetic and adaptive diversity of the species, and some aspects of its reproductive biology, and 3) thorough analysis of genetic diversity and differentiation of the ruil populations over time. The knowledge of these and other factors will allow managing and anticipating future threats of the species

Efectos combinados de la restricción hídrica, el tamaño de contenedor y la dosis de fertilizante en la supervivencia, intercambio gaseoso y atributos morfológicos en plantas de Quillaja saponaria

Quillaja saponaria is a valuable commercial and ecological Chilean native species that has suffered considerably degradation countrywide; however, the determination of the optimum characteristics of the planting stock, an important aspect in restoration projects, has receive little attention. The aim of this study was to evaluate the effect of container size and dose of fertilizer on morphological and physiological responses of Q. saponaria seedlings cultivated in a nursery under well-watered and water restricted conditions. After 27 days growing under contrasting watering regimes, growth, biomass allocation, and gas exchange were measured in 6-month-old seedlings. We found that survival, height and diameter increment, and root dry weight were higher in the water stressed seedlings cultivated in large containers. The water stressed seedlings cultivated in large containers also had superior stomatal conductance, however when the fertilizer dose was decreased, this trait decreased considerably. Thus, a superior performance in a water-restricted environment could be expected in those seedlings cultivated in larger containers with low fertilizer.Quillaja saponaria es una especie nativa del bosque nativo chileno valiosa por sus cualidades económicas y ecológicas y que ha sufrido una importante degradación a lo largo del país; sin embargo, la determinación de las características óptimas del material de plantación, un aspecto importante en proyectos de restauración, ha recibido poca atención. El objetivo de este estudio fue evaluar el efecto del tamaño de contenedor y la dosis de fertilizante en la respuesta morfológica y fisiológica de plantas de Q. saponaria cultivadas bajo dos regímenes de riego en vivero (riego normal vs. restricción hídrica). Después de 27 días de crecimiento bajo condiciones de riego contrastantes, se evaluó el crecimiento, la asignación de biomasa y variables de intercambio gaseoso en plantas de seis meses de edad. Los resultados indican que en el tratamiento de restricción hídrica las plantas cultivadas en contenedores grandes mostraron la mayor supervivencia, incremento en diámetro y altura y biomasa radical. Las plantas del tratamiento de restricción hídrica cultivadas en contenedores grandes también mostraron tasas superiores de conductancia estomática, sin embargo, cuando se disminuyó la dosis de fertilizante, esta variable disminuyó considerablemente. Se podría esperar que, aquellas plantas cultivadas en contenedores de mayor volumen y con dosis baja de fertilizante, tuvieran un mejor desempeño en ambientes con restricción hídrica.CONICYT 79150013 CONAF 067-201

Allometric Models for Estimating Aboveground Biomass in Short Rotation Crops of Acacia Species in Two Different Sites in Chile

We evaluated the ability of different allometric models to estimate the biomass production of short-rotation woody crops of Acacia dealbata, A. mearnsii and A. melanoxylon. Models considered the adjustment and validation of biomass functions and biological restrictions, such as the use of additive components of the biomass (stem, branches, and leaves). Adjustments of linear and nonlinear models of the three acacia species—established in two locations and of three densities in southern Chile—were utilized. Systems of equations were adjusted to guarantee the addition of the biomass components and the trees’ total biomass. The selection of models was performed based on their goodness of fit and predictive quality. Methods that accounted for the correlation between biomass components granted an additively consistent equations system with efficient estimates and reliable prediction intervals

Using UAVs and Machine Learning for <i>Nothofagus alessandrii</i> Species Identification in Mediterranean Forests

This study explores the use of unmanned aerial vehicles (UAVs) and machine learning algorithms for the identification of Nothofagus alessandrii (ruil) species in the Mediterranean forests of Chile. The endangered nature of this species, coupled with habitat loss and environmental stressors, necessitates efficient monitoring and conservation efforts. UAVs equipped with high-resolution sensors capture orthophotos, enabling the development of classification models using supervised machine learning techniques. Three classification algorithms—Random Forest (RF), Support Vector Machine (SVM), and Maximum Likelihood (ML)—are evaluated, both at the Pixel- and Object-Based levels, across three study areas. The results reveal that RF consistently demonstrates strong classification performance, followed by SVM and ML. The choice of algorithm and training approach significantly impacts the outcomes, highlighting the importance of tailored selection based on project requirements. These findings contribute to enhancing species identification accuracy in remote sensing applications, supporting biodiversity conservation and ecological research efforts

Allometric Models for Estimating Aboveground Biomass in Short Rotation Crops of <i>Acacia</i> Species in Two Different Sites in Chile

We evaluated the ability of different allometric models to estimate the biomass production of short-rotation woody crops of Acacia dealbata, A. mearnsii and A. melanoxylon. Models considered the adjustment and validation of biomass functions and biological restrictions, such as the use of additive components of the biomass (stem, branches, and leaves). Adjustments of linear and nonlinear models of the three acacia species—established in two locations and of three densities in southern Chile—were utilized. Systems of equations were adjusted to guarantee the addition of the biomass components and the trees’ total biomass. The selection of models was performed based on their goodness of fit and predictive quality. Methods that accounted for the correlation between biomass components granted an additively consistent equations system with efficient estimates and reliable prediction intervals