Equações de afilamento e volume para tamanhos comerciais de nothofagus obliqua e N. alpina

Timber volume of standing trees is essential information for managementdecisions. The increasing need to optimize the potential capacity of forests maintaining their conservation, requires the quantification of the different potential possible timber products. The aim was to adjust taper equations to determine volumes of different timber products for commercial stems of Nothofagus alpina and N. obliqua. Trees of both species were randomly selected in harvesting areas of Lanin National Park (Argentina).Trees were felled and cut into commercial logs, measuring diameter with bark at different heights up to the beginning of the crown, and for each tree the diameter at breast height and total height. Five taper equations were selected and non-linear regression processes were employed for the fittings. We obtained the volume through the integration of the stem profile equation and the rotation in the space thereof through solid of revolution.The Bennet and Swindel (1972) model was selected for both Nothofagus species,obtaining similar equation parameters and differences were observed at the top of the stems of larger trees. For this the use of an integrated model is not recommended. With the obtained equations it is possible to: (i) estimate volume at different heights and for different commercial diameters, and (ii) predict the height at which both species reach to a certain diameter. The model presented some statistical limitations (e.g. multicollinearity), however, the fitting of the equation and the easy understanding of the outputs support itas a useful tool in a broad range of forest applications.O volume de madeira das árvores em pé é uma informação essencial para as decisões de gestão. A crescente necessidade de otimizar a capacidade potencial das florestas mantendo sua conservação, requer a quantificação dos diferentes possíveis produtos de madeira possíveis. O objetivo era ajustar equações de afilamento para determinar volumes de diferentes produtos de madeira para hastes comerciais de Nothofagus alpina e N. obliqua. As árvores de ambas as espécies foram selecionadas ao acaso nas áreas de colheita do Parque Nacional Lanin (Argentina). As árvores foram derrubadas e cortadas em troncos comerciais, medindo o diâmetro com a casca em diferentes alturas até o início da coroa, e para cada árvore o diâmetro na altura do peito e altura total. Foram selecionadas cinco equações cônicas e foram empregados processos de regressão não-linear para ajustar. Obtivemos o volume através da integração da equação do perfil do caule e da rotação no seu espaço através do sólido da revolução. O modelo de Bennet e Swindel (1972) foi selecionado para as duas espécies de Nothofagus, obtendo parâmetros de equação semelhantes e observando-se diferenças no topo das hastes de árvores maiores. Portanto, o uso de um modelo integrado não é recomendado. Com as equações obtidas é possível: (i) estimar o volume em diferentes alturas e para diferentes diâmetros comerciais, e (ii) prever a altura em que ambas as espécies atingem um determinado diâmetro. O modelo apresentou algumas limitações estatísticas (por exemplo, multicolinearidade), no entanto, o ajuste da equação e a compreensão fácil das saídas o suportam como uma ferramenta útil em uma ampla gama de aplicações florestais.Fil: Attis Beltran, Hernan. Universidad Nacional del Comahue; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chauchard, Luis. Universidad Nacional del Comahue; ArgentinaFil: Iaconis, Ariana. University of Sydney; AustraliaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Crecimiento y producción de repoblaciones de Pinus radiata D. Don en la provincia de Guipúzcoa (País Vasco)

Esta tesis tiene la finalidad de desarrollar las bases de un modelo para la predicción del crecimiento y la producción de las masa de Pinus radiata D.don en la provincia de Guipúzcoa, (País Vasco). Los modelos se componen de funciones de transición que respetan ciertos principios biológicos y propiedades matemáticas. Además cada función fue verificada y validada, esto último cuando se contó con la muestra independiente apropiada, con ello se obtuvieron los correspondientes errores de estimación y la exactitud del modelo. El estudio consta de tres capítulos principales, el estudio de la calidad de estación, el desarrollo de las funciones de crecimiento del rodal y por último una aplicación práctica de los resultados obtenidos. La calidad de estación se estudió a través del crecimiento en altura dominante del rodal, empleando además la metodología del índice de estación o sitio. En primer lugar, se caracterizaron los patrones de crecimiento en la altura dominante en relación a la calidad de estación. De ello resultó que en las diferentes calidades de estación, los rodales de Pinus radiata mostraron culminaciones del incremento corriente anual muy tempranas para luego mantener un crecimiento sensiblemente proporcionales entre las diferentes estaciones. Se desarrolló un método independiente para la clasificación de la estación. El método se denomina del Intercepto de Crecimiento o de Intercepción y consiste en relacionar la altura dominante del rodal con el índice de estación a través de una función lineal simple. Esto se puede considerar inédito en el país y resuelve un problema planteado por los forestales del País Vasco. Finalmente se construyeron dos sistemas de curvas altura dominante-edad. que se confrontaron contra los sistemas desarrollados anteriormente. Las funciones de crecimiento del rodal se estudiaron con la variable área basal o basimétrica como variable de respuesta. Se desarrollaron diferentes métodos de predicción. Uno emplea el vínculo o relación entre dos índice de densidad, la Densidad Relativa de Curtis (1982) y el Factor de Altura de Andenmatten et al.(1997). El otro consiste en dos ecuaciones diferenciales de crecimiento que se diferencian entre sí en la variable conductora asociada con el tiempo que emplean. Mientras una usa la variable edad, al estilo tradicional, la otra se basa en la teoría del espacio de los estados y emplea la variable de estado altura dominante. La aplicación práctica consiste en unas nuevas tablas de producción para la especie. Se propone un cambio innovador en el funcionamiento de una tabla. Se podría considerar que se han logrado una mejora en las típicas tablas de selvicultura variable (tercera generación) y de selvicultura a la carta (cuarta generación). Las mismas deben considerarse como provisionales dado que las funciones de volumen que incluyen son preliminares pues su perfeccionamiento escapan a los objetivos de la tesis. SUMMARY Since recent years there is the need to improve the stand growth and yield prediction techniques. This gave rise to implement simulators that liberalize silvicultural decisions, instead of using traditional and rigid yield tables. The purpose of this thesis is to develop growth and yield models for Pinus radiáis D. Don in Guipúzcoa, Basque-Country, Spain. These models include important biological and mathematical principies. Each function was verified and validated, when the independent sample was a proper one, and it allowed to obtain an estimation error and model accuracy. This research has three main chapters: study of site quality, develop of growth functions and practica! applications of the results. Site quality was studied through both top height growth and site index methodology. Firstly the top height patterns in relation to site index were studied. The patterns showed early height annual increment and a later proportional growth, between different site qualities. To estímate site index the growth intercept method was adapted for polyciclic species as Pinus radiata. This method allowed to estímate site index in young stands (5-10 years oíd). Finally two set of site quality curves were developed and they were compared with the previously developed systems. Through this comparison, the extend of errors could be defined when inadequated curves were applied. Differences over 15 percent in top height estimations among different systems were found. The basal área was the predictable variable used in the stand's growth model. Two different prediction methods were developed. One of them uses the link or relation between two stands density indexes (STDI), Curti's Relative Density (1982) and the Height Factor (Andenmatten et al., 1997). The other one lies in two differential growth equations, which differ in the driver variable associated with the time. While one in the traditional way, uses age as a variable, the other one uses top height as a variable of state (based on the theory of states' space). The models were verified with permanent sample plots' data. The output of the models were compared with the real basal área evolutions. All of them were quité precise, with errors arround 6 and 8 percent. The practical application consisted in the construction of new yield tables for this species. An inovative change in the functioning of the tables was proposed. I consider that an improvement of the typical variable silvicultural table (3*^ generation) and in the particular silviculture table (4* generation) has been achieved. These tables should be considered as provisional ones, because they include preliminary volume functions. The improvement of these functions are beyond the objectives of this thesis

Stand development stages and recruitment patterns influence fine-scale spatial genetic structure in two Patagonian Nothofagus species

Key message: Nothofagus alpina (Poepp. et Endl.) Oerst. and Nothofagus obliqua (Mirb.) Oerst forests have strong fine-scale spatial genetic structures. The intensity of genetic structure patterns differed according to species, stand development stages, life stages, and spatial arrangement of regeneration groups. This data becomes useful for forest management as it provides an understanding of how populations evolve as well as of the consequences of disturbances and enables the establishment of sampling strategies. Context: The understanding of fine-scale spatial genetic structure in natural populations is useful for forest management. Although Nothofagus alpina (Poepp. et Endl.) Oerst. and N. obliqua (Mirb.) are important species of the Patagonian forest, little is known about the genetic structure of their populations. Aims: The main objectives were to investigate the differences in fine-scale spatial genetic structure among mature tree populations of both species considering two stands at different development stages. Genetic structure was also evaluated among life stages and spatial distribution groups of regeneration within the old-growth stand. Methods: Genetic structure was examined by microsatellite DNA analysis of regeneration and mature tree populations of both species (around 1300 individuals). Gene dispersal distance was additionally estimated. Results: In both stands and species, strong fine-scale spatial genetic structure and short dispersal distance were found. This pattern was stronger in the early successional forest, in N. obliqua populations, in earlier life stages, and in scattered regeneration. Conclusion: Stand development stages and recruitment patterns influence the fine-scale spatial genetic structure of both Nothofagus species. However, the genetic structure also differs between species.Estación Experimental Agropecuaria BarilocheFil: Sola, Georgina. Universidad Nacional del Comahue; ArgentinaFil: Sola, Georgina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; ArgentinaFil: Marchelli, Paula. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche. Grupo de Ecologia Forestal; ArgentinaFil: Marchelli, Paula. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche. Area Forestal; ArgentinaFil: Chauchard, Luis. Universidad Nacional del Comahue; ArgentinaFil: El Mujtar, Veronica Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: El Mujtar, Veronica Andrea. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentin

Mixed Nothofagus forest management: a crucial link between regeneration, site and microsite conditions

Canopy openings due to harvesting practices constitute a disturbance that changes the environmental conditions of microsites. Its impact on the relative performance of the regeneration of different tree species could also be affected by site conditions and forest structure.The objective of this study was to determine how regeneration establishment of Nothofagus mixed forests is influenced by shelterwood silvicultural system. We focused on Lanín National Reserve (Neuquén, Argentina) where this silvicultural system has been applied since the late 1980s. The microsite scale analysis (one managed forest) showed that canopy cover was a key factor conditioning Nothofagus regeneration establishment, with older and larger individuals growing in less exposed microsites. Low understory dominance and leaf litter thickness were also associated with microsites with regeneration, while successful establishment (saplings taller than 2 m) showed positive correlation with soil moisture. Variations of these patterns were observed among species reflecting their specific ecophysiological requirements. On a stand scale (two managed forests along Lacar watershed) regeneration of N. dombeyi and N. alpina showed significant correlation with site and specific basal area, while N. obliqua was correlated with total basal area. Regeneration taller than 2 m was mainly correlated with site and altitude. At both, microsite and stand scale, the relative abundance of species changed between mature trees and regeneration. In particular, for N. alpina, an abundance decrease was observed on regeneration. Our results suggest that forest management systems should diversify silvicultural practices throughout the forest landscape, to provide at each site the micro-environmental conditions required by each species in order to maintain biodiversity and forest functions.Estación Experimental Agropecuaria BarilocheFil: Sola, Georgina Giselle. Universidad Nacional del Comahue. Cátedra de Ordenación Forestal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. CCT-Patagonia Norte; ArgentinaFil: El Mujtar, Veronica Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Sistemas Forestales. Unidad de Genética Ecológica y Mejoramiento Forestal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Attis Beltran, Hernan. Universidad Nacional del Comahue. Cátedra de Ordenación Forestal; ArgentinaFil: Chauchard, Luis Mario. Universidad Nacional del Comahue. Cátedra de Ordenación Forestal; ArgentinaFil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Sistemas Forestales. Unidad de Genética Ecológica y Mejoramiento Forestal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Estructura y estado de conservación del bosque de Araucaria araucana fuera de las áreas protegidas de la Argentina: el caso de la comunidad mapuche Chiuquilihuín

Chiuquilihuín (39° 36´ S and 71° 13´ W, 5,144 ha) is an area of natural grasslands, shrublands and forests, dwelled by 300 native people of the Mapuche ethnic group devoted to extensive cattle ranging, forestry and edible seed gathering. The structure and conservation status of natural forests (27.1 % of total area), and particularly those composed of the vulnerable conifer Araucaria araucana ((Mol.) K. Koch) (“pehuén”) (9.5 %), was evaluated as an indicator of sustainable resource use of this area. Araucaria araucana formed pure and mixed stands, with Nothofagus pumilio ((Poepp. et Endl.) Krasser), “lenga”), and exhibited attributes congruent with a strategy based on large longevity, broad ecological amplitude, shade tolerance, continuous regeneration under canopy and resistance to physical and biological mortality factors. Characteristics of N. pumilio were those of an early successional, gap-dependant tree species. Forest conservation tended to be satisfactory (negligible or moderate timber extraction, absent or slight erosion and adequate regeneration of A. araucana). However, cattle grazing covered 93.3 % of forest land. Though A. araucana seedlings and saplings were abundant and vigorous, reflecting efficient mechanisms of defence against herbivores, those of N. pumilio were very scarce and injured or dead by domestic livestock. In Chiuquilihuín, long-term preservation of A. araucana depends on maintaining healthy ecosystem components and processes, and particularly N. pumilio regeneration. Consequently, management actions as land-use planning, productive diversification, environmental training, grazing restrictions and stocking reduction, enclosure and tree planting and agroforestry, should be implemented to improve forest conservation.En Chiuquilihuín (39° 36´ S y 71°13´ O, 5.144 ha) viven 300 miembros de la etnia Mapuche, en un ambiente de bosques, matorrales y pastizales naturales donde practican la ganadería extensiva, la actividad maderera y la cosecha de semillas comestibles. En este estudio se analizó la estructura y conservación del bosque natural (27,1 % del área), y en particular, el compuesto por la conífera vulnerable Araucaria araucana ((Mol.) K. Koch) (“pehuén”) (9,5 %). Araucaria araucana conformó bosques puros y mixtos con Nothofagus pumilio ((Poepp. et Endl.) Krasser) (“lenga”), y exhibió características consistentes con una estrategia basada en la gran longevidad, la tolerancia a la sombra, la regeneración continua, la extensa amplitud ecológica y la resistencia a factores de mortalidad físicos y biológicos. Las características de N. pumilio correspondieron a las de una especie sucesional temprana y dependiente de claros para regenerar. El estado de conservación de estos ecosistemas fue satisfactorio (extracción moderada de madera, erosión muy leve y regeneración adecuada de A. araucana). Sin embargo, el pastoreo del ganado doméstico se extendió en el 93,3 % de la superficie boscosa. Este proceso afectó intensamente a N. pumilio, cuyos renovales fueron escasos y en una alta proporción estaban dañados o muertos. En Chiuquilihuín, la preservación en el largo plazo de A. araucana depende del mantenimiento de los componentes y procesos ecosistémicos, en general y los que involucran a N. pumilio en particular. En consecuencia, es necesario implementar acciones de manejo (e.g., planificación del uso de la tierra, diversificación productiva, capacitación ambiental, restricción espacial y temporal de pastoreo, sistemas silvoganaderos) para mejorar el estado de conservación del bosque.Facultad de Ciencias Agrarias y Forestale

Aplicación de leyes fundamentales de la densidad a bosques de Nothofagus: I. Regla de los -3/2 o ley del autorraleo = Applicability of density rules on Nothofagus forests: I. The -3/ 2 power law or self-thinning

Con el fin de interpretar la dinámica de los bosques de Nothofagus de Norpatagonia-Argentina, se han estudiado los comportamientos de algunas leyes fundamentales relacionadas con la densidad y mortalidad de los rodales. En este artículo se expondrán los resultados obtenidos al aplicar dos expresiones relacionadas con la ley de los -3/2 o del autorraleo a los bosques puros y mixtos de Nothofagus. Del conjunto de expresiones relacionadas con esta ley se decidió trabajar más profundamente con la relación potencial entre el número de árboles y el diámetro promedio del rodal (Reineke 1933). Se emplearon datos provenientes de parcelas temporales y permanentes. La función se ajustó por dos procedimientos: regresión y gráfico o manual, que se estudiaron para diferentes tipos forestales. Se diferenciaron dos tendencias máximas lineales de la relación tamaño-densidad, la primera hasta un diámetro de 30 cm, y la segunda por encima de este último. Los dos métodos de ajuste dieron pendientes predominantemente superiores a la universal (-1.605), siendo los rodales con presencia de N. nervosa, los que presentaron la línea de densidad máxima más baja. Se logró caracterizar el comportamiento de la ley en los bosques de Nothofagus y se definió la expresión del índice de Densidad Relativa para los mismos.To understand the dynamic of Nothofagus forests in Argentina's Northern Patagonia, the behaviour of some fundamental biological laws related to stand density and mortality were studied. This paper presents the results of applying the law of -3/2 or self-thinning rule to pure and mixed stands of Nothofagus species. Although there are many equations related to this law, it was decided to mainly work with the potential relationship between number of trees and the mean diameter of the stand (Reineke 1933). Also, the mean volume and number of trees relationship was examined. Data from temporal and permanent sample plots were used. For the different forest types, different equation adjustments were made with two different methods: regression and graphical analysis. Two maximum linear trends for size-density relationship were obtained: the fisrt one up to a diameter of 30 cm and the second one over this size. The equations adjustment by means of two methods resulted in a steeper slope than the universal -1,605. The stands containing N. nervosa displayed the lowest maximum density line. The behaviour of the law was characterised. Also, the Relative Density Index for Nothofagus forests was determined.EEA BarilocheFil: Chauchard, Luis Mario. Universidad Nacional del Comahue. Asentamiento Universitario San Martín de los Andes; ArgentinaFil: Chauchard, Luis Mario. Administración de Parques Nacionales. Delegación Regional Patagonia; ArgentinaFil: Chauchard, Luis Mario. Instituto Nacional de Tecnología Agropecuaria. Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Sbrancia, Renato. Universidad Nacional del Comahue. Asentamiento Universitario San Martín de los Andes; ArgentinaFil: Sbrancia, Renato. Administración de Parques Nacionales. Delegación Regional Patagonia; ArgentinaFil: Sbrancia, Renato. Instituto Nacional de Tecnología Agropecuaria. Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Gonzalez, Marcelo Raul. Universidad Nacional del Comahue. Asentamiento Universitario San Martín de los Andes; ArgentinaFil: Gonzalez, Marcelo Raul. Administración de Parques Nacionales. Delegación Regional Patagonia; ArgentinaFil: Gonzalez, Marcelo Raul. Instituto Nacional de Tecnología Agropecuaria. Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Maresca, Leonardo. Universidad Nacional del Comahue. Asentamiento Universitario San Martín de los Andes; ArgentinaFil: Maresca, Leonardo. Administración de Parques Nacionales. Delegación Regional Patagonia; ArgentinaFil: Maresca, Leonardo. Instituto Nacional de Tecnología Agropecuaria. Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Rabino, Alberto. Universidad Nacional del Comahue. Asentamiento Universitario San Martín de los Andes; ArgentinaFil: Rabino, Alberto. Administración de Parques Nacionales. Delegación Regional Patagonia; ArgentinaFil: Rabino, Alberto. Instituto Nacional de Tecnología Agropecuaria. Estación Experimental Agropecuaria Bariloche; Argentin

Modelos de crecimiento diamétrico para Nothofagus dombeyi = Diameter growth models for Nothofagus dombeyi

Se desarrollaron varios modelos de crecimiento diamétrico para la especie Nothofagus dombeyi. La función seleccionada para el estudio es no lineal, usualmente denominada Bertalanffy-Richards. La misma se ajustó a partir de tres fuentes de datos: parcelas permanentes, análisis fustales y tarugos de incremento. Estos datos fueron segregados por estrato social y luego para cada uno se ajustó la citada función con las variables incremento diamétrico (id)- diámetro a la altura del pecho (dap). Los ajustes y análisis se realizaron a partir de dos grupos de datos. Por un lado se utilizaron datos independientes que provenían principalmente de las parcelas permanentes, mientras que por otro se emplearon series temporales dadas por los tarugos y los análisis fustales. Con ambos grupos se obtuvieron modelos con aplicaciones diferentes. Con el grupo de datos independientes se obtuvieron modelos de interés para la predicción del incremento diamétrico en el corto plazo, mientras que con las series de crecimiento se lograron modelos de una alta significancia biológica. A través de estos modelos biológicos se interpretó la dinámica de crecimiento de las especies estudiadas bajo diferentes situaciones de competencia.Models of diameter growth for Nothofagus dombeyi were developed and the selected model used for this study was non-linear and known as Bertalanffy-Richards. It was fitted from three main data sources: permanent plots (with only two measurements each), stem analysis and tree cores. The data was divided into social strata and then, for each stratum, the model was fitted according to the variables: diameter annual increment (id) and diameter at breast height (dap). The fitting, and both biological and statistical analysis, was carried out taking two different data sets into account: an independent data set, provided by permanent sample plots; and a growth series, provided by tree increment cores and stem analysis. Models with different uses were obtained through both data sets. With the independent data, we obtained models that allowed us to predict the diameter annual increment in a short time and, with the growth series, we obtained models of a high biological significance. In this sense, the biological significance of the parameters from each model was discussed when they were fitted. An interpretation of the dynamic growth of the species studied has been undertaken through the biological models under different competence status.EEA BarilocheFil: Chauchard, Luis Mario. Universidad Nacional del Comahue; ArgentinaFil: Chauchard, Luis Mario. Administración de Parques Nacionales; ArgentinaFil: Chauchard, Luis Mario. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Sbrancia, Renato. Universidad Nacional del Comahue; ArgentinaFil: Sbrancia, Renato. Administración de Parques Nacionales; ArgentinaFil: Sbrancia, Renato. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Rabino, Alberto. Universidad Nacional del Comahue; ArgentinaFil: Rabino, Alberto. Administración de Parques Nacionales; ArgentinaFil: Rabino, Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Gonzalez Peñalba, Carlos Marcelo. Universidad Nacional del Comahue; ArgentinaFil: Gonzalez Peñalba, Carlos Marcelo. Administración de Parques Nacionales; ArgentinaFil: Gonzalez Peñalba, Carlos Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Maresca, Leonardo. Universidad Nacional del Comahue; ArgentinaFil: Maresca, Leonardo. Administración de Parques Nacionales; ArgentinaFil: Maresca, Leonardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentin

Invasive alien species management in Patagonia, Argentina : prioritization, achievements and science-policy integration challenges identified by the National Parks Administration

Las especies exóticas invasoras amenazan la biodiversidad. Existen diferentes opciones para su manejo: prevención, detección temprana, erradicación, control, exclusión e incluso la “no acción”. A mayor complejidad de manejo, más información se requiere para ejecutarlo exitosamente. Además, gestores e investigadores abordan la problemática con enfoques e intereses diferentes. Mientras los primeros priorizan acciones de manejo, los segundos encuentran una oportunidad para estudiar aspectos básicos y/o teóricos, no siempre aplicados al manejo. La gestión de estas especies ofrece una ocasión única para que ambos grupos trabajen juntos en busca de beneficios mutuos. Actualmente, las decisiones de manejo suelen basarse en experiencias o información de otros países, no siempre adaptables a la problemática local. En este trabajo presentamos varias experiencias de manejo en la Administración de Parques Nacionales para exponer logros, dificultades y desafíos a los que usualmente se enfrenta la gestión institucional. Encontramos que: a) ante recursos escasos es importante generar herramientas de priorización efectivas y redes de trabajo; b) es imprescindible involucrar a la comunidad en las acciones de manejo; c) se requieren investigaciones aplicadas al manejo específico; y d) es necesario una detallada planificación previa y un monitoreo de las acciones ejecutadas y de sus resultados, basados en información técnica de primer nivel, ya que son aspectos claves para un manejo exitoso. Finalmente, gestores e investigadores deben cerciorarse que los resultados de estas investigaciones aplicadas sean conocidos y comprendidos por los tomadores de decisiones y la opinión pública, para asegurar el apoyo a la gestión.Invasive alien species are a threat to biodiversity. Management options encompass prevention, early detection, eradication, control, exclusion and even “no action.” More technical information is needed to achieve complex management actions successfully. In addition, managers and researchers address the problem with different approaches. Managers seek to prioritize management actions, and for researchers, these species are an opportunity to study basic and/or theoretical aspects, but not always applied to management. However, the management strategies offer a unique opportunity for both groups to work together seeking mutual benefits. Currently, management decisions are often based on experiences or information from other countries, which is not always useful for local problems. We present several management experiences in the Argentine National Parks Administration to show achievements, difficulties and challenges usually faced by managers. We found that: a) it is important, when resources are scarce, to generate effective prioritization tools and networks; b) it is also vital to involve the community in the management actions; c) on the other hand, research directly applied to pilot eradication is required; and d) also, a careful planning, and continuity and monitoring of management actions and environmental results based on different types of first class technical information, are key aspects for successful management. Finally, managers and researchers must ensure that the results of applied research are known and understood by decision makers and the general public, to secure management support

Twentieth century increase of Scots pine radial growth in NE Spain shows strong climate interactions

Stem radial growth responds to environmental conditions, and has been widely used as a proxy to study long-term patterns of tree growth and to assess the impact of environmental changes on growth patterns. In this study, we use a tree ring dataset from the Catalan Ecological and Forest Inventory to study the temporal variability of Scots pine (Pinus sylvestris L.) stem growth during the 20th century across a relatively large region (Catalonia, NE Spain) close to the southern limit of the distribution of the species. Basal area increment (BAI) was modelled as a function of tree size and environmental variables by means of mixed effects models. Our results showed an overall increase of 84% in Scots pine BAI during the 20th century, consistent with most previous studies for temperate forests. This trend was associated with increased atmospheric CO2 concentrations and, possibly, with a general increase in nutrient availability, and we interpreted it as a fertilization effect. Over the same time period, there was also a marked increase in temperature across the study region (0.19 °C per decade on average). This warming had a negative impact on radial growth, particularly at the drier sites, but its magnitude was not enough to counteract the fertilization effect. In fact, the substantial warming observed during the 20th century in the study area did not result in a clear pattern of increased summer drought stress because of the large variability in precipitation, which did not show any clear time trend. But the situation may change in the future if temperatures continue to rise and/or precipitation becomes scarcer. Such a change could potentially reverse the temporal trend in growth, particularly at the driest sites, and is suggested in our data by the relative constancy of radial growth after ca. 1975, coinciding with the warmer period. If this situation is representative of other relatively dry, temperate forests, the implications for the regional carbon balance would be substantial

Monitoring grape ripeness using a voltammetric electronic tongue

The use of a voltammetric electronic tongue as a tool to monitor grape ripeness is proposed herein. The electronic tongue consists of eight metallic electrodes housed inside a stainless steel cylinder. The study was carried out over a period of ca. 1 month (August 2012) on different grape varieties (Macabeo, Chardonnay, Pinot Noir, Cabernet Sauvignon, Shyrah, Merlot and Bobal) from various vineyards near Requena and Utiel (Valencia, Spain). Apart from the electrochemical studies, the physico-chemical parameters, such as, Total Acidity, pH and °Brix, were also determined in grapes. The PCA models, obtained using the physico-chemical or electrochemical data, showed variation of ripenesswith time.Moreover the studywas completed by using partial least squares (PLS) regression in an attempt to establish a correlation between the data collected from the electronic tongue and Total Acidity, pH and °Brix values. A good predictive modelwas obtained for the prediction of Total Acidity and °Brix. These results suggest the possibility of employing electronic tongues to monitor grape ripeness and of, therefore, evaluating the right time for harvesting.The financial support from the Spanish Government (project MAT2012-38429-C04-01) and the Generalitat Valenciana (Valencian Regional Government; project PROMETEO/2009/016) is gratefully acknowledged.Campos Sánchez, I.; Bataller Prats, R.; Armero, R.; Gandía Romero, JM.; Soto Camino, J.; Martínez Mañez, R.; Gil Sánchez, L. (2013). Monitoring grape ripeness using a voltammetric electronic tongue. Food Research International. 54(2):1369-1375. https://doi.org/10.1016/j.foodres.2013.10.011S1369137554