Pablo Donoso
Universidad Austral de Chile, Silviculture, Faculty Member
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Research Interests: Humanities and Bosque
El presente libro corresponde a la segunda publicación de la serie Estudios en Silvicultura de Bosques Nativos, la que se inició el año 2013. Con esta serie de libros se pretende difundir, de manera periódica, avances en estudios sobre... more
El presente libro corresponde a la segunda publicación de la serie Estudios en Silvicultura de Bosques Nativos, la que se inició el año 2013. Con esta serie de libros se pretende difundir, de manera periódica, avances en estudios sobre silvicultura y materias relacionadas (ecología forestal aplicada y restauración), que se han llevado a cabo especialmente en Chile, pero también en otras regiones del mundo en los que existen bosques templados. El libro se dividió en tres grandes secciones. La primera, sobre Ecología Forestal, aborda temas sobre ecología de la regeneración, ecología de claros de bosques y el uso de la fitosociología como herramienta metodológica para el diagnóstico florístico y ecológico de los bosques. La segunda sección del libro trata sobre la Silvicultura y el Manejo, e incluye cinco trabajos que versan sobre el crecimiento, la silvicultura y el manejo de los bosques secundarios en Chile, además de la silvicultura de bosques de Ciprés de la Cordillera en Argentina y sobre el potencial del silvopastoreo. Finalmente, la sección de Degradación y Restauración incluye cinco trabajos, dos de ellos sobre degradación de bosques (en Chile y Argentina) y los otros tres sobre restauración de bosques, uno en Chiloé y los otros dos en bosques de la costa oeste de los Estados Unidos. En conjunto esta gran diversidad de trabajos permite a los lectores recorrer múltiples bosques templados de diversas regiones de América. Además este libro provee diferentes perspectivas de una gran diversidad de silvicultores y ecólogos forestales con respecto a cómo manejar bosques y ecosistemas forestales de acuerdo especialmente a sus condiciones de desarrollo y de conservación en función de mantener, incrementar o recuperar su resiliencia y productividad. Esperamos que esta publicación sea de interés, y en especial sea útil para los lectores, silvicultores y tomadores de decisiones y, que contribuya de esa forma a un mejor manejo y restauración de nuestros bosques nativos. Creemos que este es un aporte más en apoyo a la conservación o recuperación de los valores y las riquezas asociados a los bosques templados. Los nuevos conocimientos teóricos y prácticos para el manejo y restauración de los bosques, varios de ellos expresados en este libro, debiesen fluir hacia quienes en definitiva intervienen los bosques. Si bien la tarea del manejo forestal sostenible es compleja, es fundamental la generación de mayores y mejores puentes de comunicación entre investigadores, instituciones vinculadas a la conservación y manejo de ecosistemas forestales, propietarios de bosques nativos y la sociedad en general. Este libro representa una contribución a esa tarea, los resultados de investigaciones dirigidas a la aplicación de prácticas para el buen manejo de nuestros bosques nativos
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Research Interests: Geography and Humanities
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Background: South America has the largest area of temperate forests in the Southern Hemisphere, which grow in diverse site conditions. The aim of this paper is to review the practices of silviculture applied and recommended for these... more
Background: South America has the largest area of temperate forests in the Southern Hemisphere, which grow in diverse site conditions. The aim of this paper is to review the practices of silviculture applied and recommended for these temperate forests, and to discuss prospects to develop new silvicultural proposals to improve sustainability, adaptation and in-situ conservation of forest ecosystems. Methods: We reviewed the silviculture knowledge in four major forest types: 1) The Nothofagus-dominated forests of south-central Chile; 2) the Angiosperm-dominated evergreen forests; 3) the Nothofagus and Austrocedrus chilensis (D.Don) Pic. Serm. & Bizzarri forests in the Argentinean Northern Patagonia; and 4) the Cool temperate Nothofagus forests and Magellanic rainforests. Results: In Chile, both Nothofagus-dominated and Angiosperm-dominated evergreen forests are diverse in tree species, and mixed-species silviculture with commercially valuable species of variable shade tolerance is mos...
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The influence of functional diversity on ecosystem productivity has practical implications for the carbon sequestration potential of forest ecosystems. Vertical stratification may be one key aspect of functional diversity that influences... more
The influence of functional diversity on ecosystem productivity has practical implications for the carbon sequestration potential of forest ecosystems. Vertical stratification may be one key aspect of functional diversity that influences stand productivity through differential resource use. Although additive basal area of canopy and emergent species has been reported in some forests, it is unclear whether this represents significant additive productivity, or mainly a reflection of the great longevity of the emergent trees. We asked if the presence of emergent <i>Nothofagus dombeyi</i> influences carbon sequestration in wood of the associated canopy species in an old-growth temperate forest in south-central Chile, the canopy species all being more shade-tolerant than <i>N. dombeyi</i>. We estimated wood volume increment of all trees on four pairs of plots in old-growth stands in Parque Nacional Puyehue, each pair consisting of one 25×25 m plot with emergent tr...
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Temperate mixed forests of South America extend mostly from 33°S to 55°S latitude and between the Pacific Ocean and the Patagonian Steppe east of the Andes Mountains. West of the Andes in Chile, in a high precipitation regime, the most... more
Temperate mixed forests of South America extend mostly from 33°S to 55°S latitude and between the Pacific Ocean and the Patagonian Steppe east of the Andes Mountains. West of the Andes in Chile, in a high precipitation regime, the most diverse and large forest types develop. These forests simplify in composition and structure toward the south due to reductions in temperature and in a more pronounced manner east of the Andes, in Argentina, because of an abrupt reduction of the precipitations. Descriptions of the main temperate mixed forest types of Chile and Argentina are presented, focusing on ecologic issues and management proposals. For Chile, we address in this chapter secondary and old-growth forests of the evergreen forest type and secondary forest dominated by Nothofagus spp. For Argentina, we discuss the case of mixed Nothofagus spp. forests in the old-growth phase and of N. dombeyi and Austrocedrus chilensis mixed forests in the transition from the mesic to the xeric zone. There is a strong ecological and silvicultural base knowledge for the sustainable management of these mixed forests. However, with a few exceptions, its broad application is a pendant matter in both countries.
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SUMMARY Young secondary forests of Drimys winteri have excellent growth and regeneration, and cover an area of 230,000 hectares in Chile. However, there is no supply of high-value timber to feed the growing market opportunities. The... more
SUMMARY Young secondary forests of Drimys winteri have excellent growth and regeneration, and cover an area of 230,000 hectares in Chile. However, there is no supply of high-value timber to feed the growing market opportunities. The objective of this study was to evaluate the profitability of thinning trials in secondary forests of Drymis winteri in a medium-productivity site. The thinning treatments were considered late thinning, and were named as moderate thinning (E1), heavy (E2) and heavy (E3), in addition to a control treatment (E4). The yield was determined using the net present value (NPV), land expected value (LEV), and modified internal rate of return (MIRR), incorporating discount rates of 6 %, 8 % and 10 % and low administration costs in two scenarios, no costs before thinning (S1) and costs since the establishment of the stand (S2). The results for the NPV and VPS in S2 were negative, in contrast with S1, which doubled its profitability compared with the control treatmen...
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We evaluated height and diameter growth of 19 sugar maple (Acer saccharum Marsh.) and 20 American beech (Fagus grandifolia Ehrh.) saplings in a 22 ac northern hardwood selection system stand cut in Fall 1973 to a residual density of 73... more
We evaluated height and diameter growth of 19 sugar maple (Acer saccharum Marsh.) and 20 American beech (Fagus grandifolia Ehrh.) saplings in a 22 ac northern hardwood selection system stand cut in Fall 1973 to a residual density of 73 ft²/ac, and again in Summer 1993 to 82 ft²/ac. We classified the sample trees according to the proportion of total age represented by the 19 yr period after the 1973 selection cutting: more than 80% (young trees), 67–80% (intermediate trees), and less than 67% (old trees). Young trees reached 1 in. dbh almost one decade sooner than old trees (25.7 vs. 33.8 yr), but the two age groups did not differ significantly in height when they reached that threshold diameter. Young and intermediate-aged trees grew more rapidly in height than older trees, especially during the first 10 yr after cutting (6.1 vs. 4.9 ft during the 10 yr period). Height growth of saplings for the last 9 yr of the first cutting cycle did not differ significantly from that prior to the...
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Hace 5 años iniciamos un proyecto de investigación a largo plazo cuyo principal objetivo fue el estudiar bosques turbosos inalterados y quemados de Pilgerodendron uviferum en el sur de Chiloé, de tal forma de desarrollar la base... more
Hace 5 años iniciamos un proyecto de investigación a largo plazo cuyo principal objetivo fue el estudiar bosques turbosos inalterados y quemados de Pilgerodendron uviferum en el sur de Chiloé, de tal forma de desarrollar la base ecológica-científica necesaria para futuras estrategias de conservación y restauración. Enfocamos el trabajo en tres importantes aspectos relacionados a la restauración: a) entender los procesos ecológicos que ocurren en bosques turbosos inalterados, b) analizar el grado de recuperación natural de los bosques quemados, y c) explorar algunas opciones para su restauración. Según nuestros resultados, pese a ser P. uviferum una especie tolerante al estrés, su recuperación luego de incendios es extremadamente lenta. Setenta años después de incendios catastróficos, a escala de paisaje existe una muy baja frecuencia de árboles semilleros y su potencial de diseminación de semillas es extremadamente limitado. Nuestros resultados revelan que incendios severos pueden p...
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Seedling density according to structure, dominance and understory cover in old-growth forest stands of the evergreen forest type in the coastal range of Chile Densidad de plántulas de acuerdo a la estructura, dominancia y cobertura del sotobosque en bosques siempreverdes adultos en la cordillera ...more
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Valdivian Temperate Rainforests in Chile have a global conservation value, but nowadays many correspond to secondary forests following regeneration in agricultural and burned lands, and to high-graded old-growth due to mismanagement,... more
Valdivian Temperate Rainforests in Chile have a global conservation value, but nowadays many correspond to secondary forests following regeneration in agricultural and burned lands, and to high-graded old-growth due to mismanagement, especially at mid to low elevations. Perspectives for increasing old-growth attributes in these productive forests through silviculture are high considering the diverse demands of ecosystem services and the high timber value of tree species. In the Llancahue experimental forest (40°S Lat) we implemented three ecological silviculture approaches: variable-density thinning in a Nothofagus dombeyi secondary forest (NDS), irregular shelterwood in a mature N. dombeyi forest (NDM), and single-tree selection cutting in a partially harvested old-growth forest (OG). Based upon an old-growth index (OGI) that includes density, basal area (BA), BA of the trees >80 cm in diameter, ba of shade-tolerant species, and the Gini coefficient, and aims to estimate how clo...
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Stand density management (DMD) diagrams are graphical models of uniform stands at different ages that reflect the relationship among size, density, competition, site occupancy and self thinning. DMDs allow planning of thinnings through... more
Stand density management (DMD) diagrams are graphical models of uniform stands at different ages that reflect the relationship among size, density, competition, site occupancy and self thinning. DMDs allow planning of thinnings through the definition of a target stand and the upper and lower limits of site occupancy. In this study we developed a DMD for Drimys winteri second-growth forests in southern Chile by using 300 sampling units with at least 70 % basal area of this species. The resulting DMD allowed the determination of the maximum density line, the volume and height isolines, and the evaluation of its use with information from permanent plots thinned 21 years ago. The results of the functions in the DMD present acceptable predictive power, and illustrate the usefulness and precision of this tool to plan silviculture activities. Results from applying the DMD suggest maintenance of site occupancy levels between the subutilization zone (30 % relative density index (RDI)) and th...
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Young secondary forests of Drimys winteri have excellent growth and regeneration, and cover an area of 230,000 hectares in Chile. However, there is no supply of high-value timber to feed the growing market opportunities. The objective of... more
Young secondary forests of Drimys winteri have excellent growth and regeneration, and cover an area of 230,000 hectares in Chile. However, there is no supply of high-value timber to feed the growing market opportunities. The objective of this study was to evaluate the profitability of thinning trials in secondary forests of Drymis winteri in a medium-productivity site. The thinning treatments were considered late thinning, and were named as moderate thinning (E1), heavy (E2) and heavy (E3), in addition to a control treatment (E4). The yield was determined using the net present value (NPV), land expected value (LEV), and modified internal rate of return (MIRR), incorporating discount rates of 6 %, 8 % and 10 % and low administration costs in two scenarios, no costs before thinning (S1) and costs since the establishment of the stand (S2). The results for the NPV and VPS in S2 were negative, in contrast with S1, which doubled its profitability compared with the control treatment. The E...
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Early performance of planted Nothofagus dombeyi and Nothofagus alpina in response to light availability and gap size in a high-graded forest in the south-central Andes of Chile Respuesta temprana de plantaciones de Nothofagus dombeyi y Nothofagus alpina a la disponibilidad de luz y tamaño de clar...more
Postmodern cognitive sciences have identified many historical examples of social downfalls, or even the collapse of entire civilizations, and there has been one common cause: a crisis of perception. A crisis of perception has its origin... more
Postmodern cognitive sciences have identified many historical examples of social downfalls, or even the collapse of entire civilizations, and there has been one common cause: a crisis of perception. A crisis of perception has its origin in a cognitive disconnection of one specific culture with the socio-environmental context from which it arose. Partially this disconnection is possible due to the characteristics of the nervous system, as a system with organizational closure, and consequently the nature of language, as an autonomous cognitive process, developed and performed by human beings. It is the language that gives “sense” to our process of living, but it confuses us too, as ideas are never concrete realities. The cultural context defines “meanings”, bringing this way forth to worldviews that define social coexistence, specific understandings that define disciplines and specific values that define what is valuable. However, language as a behavioral process taking place in human beings, is not about a “universal truth” but a “human truth” that emerges in the process of human living, and consequently it is determined by the human experience. In short, under this prospect, we humans cannot refer to a non-human reality, as we are only capable to perceive and think the reality that our cognitive system is structurally able to perform. Therefore, a so-called “objective” knowing is simply not possible, which in turn leaves a set of strong implications regarding any discipline, including economics. Disciplines are networks of conversations that coordinate themselves setting linguistic (and symbolic) boundaries to the “outside” in the course of internal interactions among the members of each discipline. In this manner, every discipline develops a way to understand (a “disciplinary story”) that sets the framework of rationality within, together with an internal “specialized” technical language. Both the disciplinary understanding and language are not objective realities, but ever-changing cultural phenomena determined by the nature of social phenomena as linguistic processes, even in the so-called “hard” or “natural” sciences. As any disciplinary knowledge, economic thinking has been developed under a certain set of foundational concepts that are implicitly believed. Beliefs arise in the interplay of the different human domains of existence, such as experiences (evidences), cultural background, preferences and the internal drift that the collectivity of a discipline have performed. Disciplinary (scientific) knowledge is never only about facts or truths but involves all the aspects of human living. Neoclassical economics have received critics from the scientific world since decades. Therefore, it is extremely interesting to study the existing incoherencies between neoclassical economics and other scientific disciplines, like natural sciences, in order to discover what set of beliefs are guiding current mainstream economics, and why such incoherencies have been kept for so long.
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Background: The genus Nothofagus is a key component of the Valdivian temperate rainforests of South America, and several of its species have shown promising growth in plantations. Plantations with these species are an opportunity to... more
Background: The genus Nothofagus is a key component of the Valdivian temperate rainforests of South America, and several of its species have shown promising growth in plantations. Plantations with these species are an opportunity to diversify the Chilean forest sector, ideally through mixed-species arrangements, but the existing literature in this regard is scarce. This work aimed to evaluate individual tree growth for three Nothofagus species in a mixed plantation, considering two types of neighbourhoods. Methods: In a mid-elevation site in the foothills of the Andes ranges we evaluated growth of Nothofagus alpina (Poepp. & Endl.) Oerst, Nothofagus dombeyi (Mirb.) Oerst and Nothofagus obliqua (Mirb.) Oerst according to their neighbourhood, comprised of evergreen or deciduous tree species. We conducted stem analyses for 30 trees (10 per species, one-half with each type of neighbourhood; 370 cross-sections in total) and compared growth in diameter (d), height (h), and volume (v) for ...
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Research Interests: Biology and Interciencia
Hardwood-dominated forests in south-central Chile have shade-tolerant and mid-tolerant tree species capable of regenerating and growing well in partial shade. To test the potential for using an uneven-aged silviculture in these forests,... more
Hardwood-dominated forests in south-central Chile have shade-tolerant and mid-tolerant tree species capable of regenerating and growing well in partial shade. To test the potential for using an uneven-aged silviculture in these forests, we established single-tree selection treatments at two mid-elevation sites within the Evergreen forest type in the Coastal range (Llancahue and Los Riscos, 40–42° S Lat). They had an average initial basal area of 70–80 m2 ha−1. In each stand, we established four 2000 m2 plots with a residual basal area of ~40 m2 ha−1, and four with a residual basal area of ~60 m2 ha−1. We planned for a maximum residual diameter of 80 cm, but needed to leave 20%–25% of the residual basal area in larger trees due to their great abundance in these old-growth forests. We re-measured these plots 5–6 years after the cuttings. We used mixed-effects models to evaluate the periodic annual increment (pai) in diameter and the abundance of tree regeneration, and linear models to...
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Environmental factors affect the spatial arrangement of survival and damage of outplanted Nothofagus dombeyi seedlings in the chilean andes Interciencia, vol. 34, núm. 2, febrero, 2009, pp. 100-105
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Nothofagus dombeyi is distributed on very diverse sites in the temperate forests of Chile and Argentina. In Chile, studies on its dynamics and productivity in forests, where it is the dominant species, have been carried out mainly in the... more
Nothofagus dombeyi is distributed on very diverse sites in the temperate forests of Chile and Argentina. In Chile, studies on its dynamics and productivity in forests, where it is the dominant species, have been carried out mainly in the foothills of the Andes, but the productivity and growth of these forests in the Coastal Range are almost unknown. The objective of this study was to evaluate the construction of a single dominant height/age growth model for two homogeneous edaphoclimatic zones (ZEH 2 and 5) previously defined for this species in the Coastal Range of southcentral Chile. The results showed that the Chapman-Richards model was the best candidate function, in terms of goodness of fit and predictive capabilities. Using this function, specific parameters (a, b and c) were obtained for each zone, from which site models were constructed by the Algebraic Difference Approach method for a base age of 35 years. This model is intended to contribute to better estimations of site p...
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Forest understories are essential to plant diversity and ecosystem functioning. However, studies about changes in understory patterns as affected by varying precipitation are scarce. Pure Nothofagus pumilio (common name: lenga) forests... more
Forest understories are essential to plant diversity and ecosystem functioning. However, studies about changes in understory patterns as affected by varying precipitation are scarce. Pure Nothofagus pumilio (common name: lenga) forests dominate the eastern side of the Andes mountains in Patagonia across an ample range of precipitation (~1500-500 mm). By studying the same forest type, in the same developmental stage (old-growth), we aimed to isolate the effects of precipitation upon these N. pumilio ecosystems, particularly for the understory. Three sites were selected with annual average precipitations of ~1000 mm (humid), ~800 mm (mesic), and 600 mm (dry), with a distance of 30 km between the humid and the dry sites, and only 18 km between the mesic and the dry sites. In each site, we established three 40 × 40 m plots in 4 blocks, and 30 1 m 2 regeneration subplots within each plot. In each subplot we measured vascular plant cover, richness and diversity (alpha and beta), litter cover and coarse woody debris, plus several abiotic variables. We analyzed the data with mixed analysis of variance, differences of understory plant communities through blocked distance-based multivariate analysis of variance, and visualized the groups (sites) with non-metric multidimensional scaling. Indicator species at each site were identified through blocked species indicator analysis. The dry site differed significantly compared to the humid and mesic sites, with the lowest understory cover (4 vs. 82-78%), plant richness (15 vs. 25-26 species), and Simpson diversity index (0.05 vs. 0.66-0.64). Beta turnover diversity was higher between the dry site with either the humid and the mesic sites (βt = 0.613 and 0.561, respectively), which in turn had more species in common (βt = 0.115). An increase in exposed mineral soil, soil water content, and leaf area index occurred from dry to humid sites, and vice versa for transmitted radiation and litter cover. All sites had different indicator species, but with indicator values increasing from dry to humid sites. The dramatic impoverishment of the plant community once precipitation drops within the range of 800 and 600 mm per year in Northern Patagonia sets a warning to the potential effects of climate change upon N. pumilio-dominated forest ecosystems and their plant diversity. Some forest management and potential adaptation strategies are proposed.
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La degradación de los bosques es un problema que afecta en la actualidad a cerca de la mitad de los bosques del mundo, y tiene variadas y negativas consecuencias ambientales, sociales y económicas. La degradación se vincula con la acción... more
La degradación de los bosques es un problema que afecta en la actualidad a cerca de la mitad de los bosques del mundo, y tiene variadas y negativas consecuencias ambientales, sociales y económicas. La degradación se vincula con la acción antrópica directa, como la explotación forestal insostenible y la recolección excesiva de productos, o indirecta, como la ocurrencia de invasiones biológicas o plagas. Estas actividades afectan negativamente las características estructurales del bosque, especialmente debido a que disminuyen el porcentaje de especies maderables de alto valor, la sanidad y calidad del bosque en general, y la regeneración natural por incremento de especies competidoras. Este patrón también se ha manifestado en Chile, principalmente desde mediados del siglo XIX, en donde los bosques nativos han sido degradados especialmente mediante explotación o cosecha de las especies de mayor valor comercial, lo cual es frecuentemente acompañado por ingreso de ganado, generando bosques residuales de menor valor y funcionalidad. En este contexto, para rehabilitar bosques de mayor integridad ecológica y valor comercial a partir de estos bosques degradados, es necesario entender qué es un bosque degradado, es decir, el concepto y el estado que caracteriza a un bosque degradado, así como el proceso que conduce a un bosque hacia su degradación. En este capítulo se desarrolla cada uno de estos puntos y se presenta una propuesta de evaluación de la degradación a escala de rodales de bosques adultos degradados de los tipos forestales siempreverde y coihue-raulí-tepa, los de mayor potencial productivo de la región centro sur de Chile, para desde ahí plantear opciones silviculturales tendientes a la rehabilitación de estos bosques.