@article{alvarez_allen_albaugh_stape_bullock_song_2013, title={Factors influencing the growth of radiata pine plantations in Chile}, volume={86}, DOI={10.1093/forestry/cps072}, abstractNote={We examined environmental factors affecting growth rates of Pinus radiata in Chile. The relationships between annual volume growth and soil, climate, canopy and stand factors were analysed using data from 48 permanent sample plots in P. radiata plantations in central Chile. Water availability (as affected by precipitation, soil water holding capacity and potential evapotranspiration) appeared to be the factor most limiting to leaf area and growth. Maximum growing season temperature also negatively affected growth. Sites with the highest productivities had the lowest annual water deficits. The most productive sites used water and light more efficiently. Growth per unit of potential evapotranspiration ranged from 0.5 to 1.6 kg of wood per m3 of water and growth per unit of radiation ranged from 0.3 to 0.5 g of wood per MJ of photosynthetically active radiation for low and high productivity sites. The inclusion of simple climatic variables such as maximum temperature and precipitation into Chilean P. radiata growth and yield models should improve their performance.}, number={1}, journal={Forestry}, author={Alvarez, J. and Allen, Howard and Albaugh, T. J. and Stape, J. L. and Bullock, B. P. and Song, C.}, year={2013}, pages={13–26} }
 @article{rubilar_albaugh_allen_alvarez_fox_stape_2013, title={Foliage development and leaf area duration in Pinus radiata}, volume={304}, ISSN={["0378-1127"]}, DOI={10.1016/j.foreco.2013.05.044}, abstractNote={Abstract Site-specific constraints on foliage development and leaf area duration were investigated in two-year-old Pinus radiata D. Don. plantations established under a factorial combination of soil tillage (shovel vs. subsoil + bedding + shovel), fertilization (B only vs. N, P, K, and B), and weed control (pre-plant vs. pre-plant + two-year banded) at three contrasting textural (sand, clay and ash) and climatic soil-site conditions in the Central Valley of Chile. We examined site effects and five treatments at each site to test hypotheses that soil tillage and nutrient and water limitations, would not influence foliage development or leaf area duration. Site effects were evident for foliage development and leaf area duration. Improved nutrient availability increased fascicle length at the sand and clay sites. Improved water availability increased fascicle length and leaf area duration at the sand site, and increased fascicle number at the sand and clay sites. Soil tillage reduced fascicle length at the ash site. Fascicle length may be influenced by factors including water and nutrient availability and soil and air temperature; however based on our data and indications in the literature that the largest effects on foliage length have been associated with resource availability we hypothesize that tillage may have induced nutrient and or water limitations at the ash site.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Rubilar, Rafael A. and Albaugh, Timothy J. and Allen, H. Lee and Alvarez, Jose and Fox, Thomas R. and Stape, Jose L.}, year={2013}, month={Sep}, pages={455–463} }
 @article{rubilar_albaugh_allen_alvarez_fox_stape_2013, title={Influences of silvicultural manipulations on above- and belowground biomass accumulations and leaf area in young Pinus radiata plantations, at three contrasting sites in Chile}, volume={86}, ISSN={["1464-3626"]}, DOI={10.1093/forestry/cps055}, abstractNote={There is a limited understanding of how resource availability (water+nutrients) interacts with soil physical properties in determining above- and belowground biomass allocation in radiata pine (Pinus radiata D.Don) plantations. We studied total above- and belowground biomass accumulation, and belowground biomass allocation (coarse and fine roots) in response to three contrasting silvicultural treatments (soil tillage, weed control and fertilization) applied to three sites of contrasting climate and soil textures in the Central Valley of Chile. At each site, tree growth (aboveground, belowground and total biomass), aboveground:belowground biomass ratio and leaf area index (LAI) were significantly increased by weed control. Weed control produced larger and more consistent responses in growth than subsoiling or fertilization. Weed control appears to ameliorate both water and nutrient limitations. The large differences in growth and biomass accumulation by weed control within sites, were mainly attributed to large differences in soil water availability, and among sites also due to atmospheric water demand differences. A linear relationship was established between LAI and stand growth across sites. The slope of the relationship, stemwood growth efficiency, was different among sites and was related to water and nutrient limitations. Stemwood growth efficiency varied from 2.9 m3 ha−1 year−1 to 7.1 m3 ha−1 year−1 per unit of leaf area, with lower growth efficiencies found on sites with greater water constraints.}, number={1}, journal={FORESTRY}, author={Rubilar, Rafael A. and Albaugh, Timothy J. and Allen, H. Lee and Alvarez, Jose and Fox, Thomas R. and Stape, Jose L.}, year={2013}, month={Jan}, pages={27–38} }
 @article{alvarez_mitasova_allen_2011, title={ESTIMATING MONTHLY SOLAR RADIATION IN SOUTH-CENTRAL CHILE}, volume={71}, ISSN={["0718-5820"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84255171688&partnerID=MN8TOARS}, DOI={10.4067/s0718-58392011000400016}, abstractNote={La radiacion solar es un componente clave en los modelos basados en procesos. La cantidad de esta energia depende de la ubicacion, epoca del ano, y tambien de las condiciones atmosfericas. Varias ecuaciones y modelos han sido desarrollados para diferentes condiciones, utilizando datos historicos de las redes de estaciones meteorologicas o de las mediciones por satelite. Sin embargo, las estimaciones de la radiacion solar son demasiado locales con estaciones meteorologicas, o con una resolucion muy gruesa cuando se trabaja con satelites. En el presente estudio se estimo radiacion solar global mensual para la region centro sur de Chile mediante el uso del modelo r.sun y se valido con observaciones de estaciones meteorologicas automaticas. Se analizo el desempeno de los resultados de la irradiacion global con los modelos Hargreaves-Samani (HS) y Bristol-Campbell (BC). Las estimaciones del modelo calibrado r.sun explican un 89% de la varianza (r2 = 0.89) en valores medios mensuales observados. El modelo se comporto muy bien para una amplia zona de las condiciones de Chile, comparados con los modelos HS y BC. Nuestras estimaciones de la radiacion global utilizando el modelo r.sun podrian ser mejoradas aun mas con una posterior calibracion a partir de observaciones y una mejor estimacion de la nubosidad en la medida que esten disponibles. Con procedimientos adicionales, el modelo r.sun podria ser utilizado para proporcionar estimaciones espaciales de la radiacion solar diaria, semanal, mensual, y anual.}, number={4}, journal={CHILEAN JOURNAL OF AGRICULTURAL RESEARCH}, author={Alvarez, Jose and Mitasova, Helena and Allen, H. Lee}, year={2011}, pages={601–609} }
 @article{rubilar_allen_alvarez_albaugh_fox_stape_2010, title={Silvicultural manipulation and site effect on above and belowground biomass equations for young Pinus radiata}, volume={34}, ISSN={["1873-2909"]}, DOI={10.1016/j.biombioe.2010.07.015}, abstractNote={There is little understanding of how silvicultural treatments, during the early stages of tree development, affect allometric relationships. We developed and compared stem, branch, foliage, coarse and fine root biomass, and leaf area estimation equations, for four-year-old genetically improved radiata pine trees grown on three contrasting soil-site conditions. At each site, selected trees were destructively sampled from a control (shovel planted, no weed control, fertilized with 2 g of boron), a shovel planted + weed control (2 first years) + complete fertilization (nitrogen + phosphorus + boron 2 first years + potassium 2nd year), and a soil tillage (subsoil at 60 cm) + weed control (first 2 years) + complete fertilization treatment. Tissues were separated into foliage, branch, stem, fine and coarse roots (>2 mm). Regression equations for each tree biomass tissue versus leaf area were fit for each site and compared among treatments and sites with the same genetic material. Our results indicated that individual tree biomasses for young plantations are affected by silvicultural treatment and site growing conditions. Higher variability in estimates was found for foliage and branches due to the ephemeral nature of these components. Stem biomass equations vary less, but differences in biomass equations were found among sites and treatments. Coarse root biomass estimates were variable but less than expected, considering the gradient among sites. Similar to stem biomass, a simple positive general linear relationship between root collar diameter, or diameter at breast height with coarse roots biomass was developed across sites and treatments.}, number={12}, journal={BIOMASS & BIOENERGY}, author={Rubilar, Rafael A. and Allen, H. Lee and Alvarez, Jose S. and Albaugh, Timothy J. and Fox, Thomas R. and Stape, Jose L.}, year={2010}, month={Dec}, pages={1825–1837} }
 @article{albaugh_rubilar_alvarez_allen_2004, title={Radiata pine response to tillage fertilization and weed control in Chile}, volume={25}, DOI={10.4067/s0717-92002004000200002}, abstractNote={Se iniciaron en el ano 2000 ensayos para investigar la respuesta a la preparacion de suelos (pala vs. subsolado), control de malezas (sin control vs. dos anos en bandas) y fertilizacion (1,5 g de B por planta vs. 150 g de fosfato diamonico + 1,5 g de B por planta) al establecimiento de pino radiata (Pinus radiata D. Don) en Chile. Los ensayos se establecieron en sitios con suelos de cenizas volcanicas recientes, cenizas volcanicas antiguas (rojo arcillosos volcanicos), arenas volcanicas y sedimentos fluviales depositados sobre material granitico. El diseno experimental correspondio a parcelas divididas, donde areas con preparacion de suelos (parcelas principales) fueron divididas en parcelas con control de malezas y fertilizacion (subparcelas), considerando un area minima de tratamiento de 0,4 ha incluyendo buffers de 10 m entre parcelas. Mediciones de altura, diametro de cuello y diametro a la altura del pecho (DAP) fueron obtenidas durante tres anos, junto con muestreos foliares durante los dos primeros anos. Al tercer ano de crecimiento, todos los sitios presentaron respuestas positivas al control de malezas con un promedio de 3,1 cm en diametro y 1 m en altura. Respuestas positivas a la fertilizacion en altura (0,1 m) fueron obtenidas solo en sitios de arenas volcanicas; analisis foliares nutricionales revelaron una escasa absorcion de los nutrientes en la plantacion posiblemente dada una aplicacion tardia de los fertilizantes. El subsolado mostro respuestas positivas en suelos de arenas volcanicas y de sedimentos fluviales, sin embargo, la respuesta fue 95% y 42% menor a la obtenida para control de malezas en estos sitios respectivamente. El control de malezas y el subsolado redujeron la variabilidad en altura en todos los sitios. Nuestra hipotesis es que la temprana respuesta al control de malezas se mantendra hasta la edad de rotacion (curva tipo B) para sitios de cenizas volcanicas antiguas y en sedimentos fluviales sobre material granitico; no obstante, en sitios de cenizas volcanicas recientes y arenas volcanicas esta respuesta decrecera o desaparecera (curva tipo C) a la edad de rotacion. Indudablemente, en todos los sitios evaluados, el control de malezas es recomendable. La fertilizacion es recomendable junto con el control de malezas en sitios de arenas volcanicas. Por tanto, estudios adicionales son necesarios para determinar la epoca oportuna de fertilizacion que asegure una adecuada absorcion de los nutrientes por parte de la plantacion. El subsolado no es necesario en los sitios evaluados, sin embargo, efectos indirectos tales como: mejor accesibilidad, rendimiento y calidad de plantacion, deben ser cuantificados al evaluar los beneficios de esta actividad.}, number={2}, journal={Bosque}, author={Albaugh, T. J. and Rubilar, R. and Alvarez, J. and Allen, Howard}, year={2004}, pages={5–15} }