As human activities are increasingly domesticating the Earth's ecosystems, new selection pressures are acting to produce winners and losers amongst our wildlife. With particular emphasis on plants, Briggs examines the implications of human influences on micro-evolutionary processes in different groups of organisms, including wild, weedy, invasive, feral, and endangered species. Using case studies from around the world, he argues that Darwinian evolution is ongoing. He considers how far it is possible to conserve endangered species and threatened ecosystems through management, and questions the extent to which damaged landscapes and their plant and animal communities can be precisely recreated or restored. Many of Darwin's ideas are highlighted, including his insights into natural selection, speciation, the vulnerability of rare organisms, the impact of invasive species, and the effects of climate change on organisms. An important text for students and researchers of evolution, conservation, climate change and sustainable use of resources.

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Plant Microevolution and Conservation in Human-influenced Ecosystems

Araucaria araucana (araucaria o pehuen) desarrolla normalmente en su habitat natural un crecimiento arboreo con altura > 20 m. Sin embargo, en 1984, en la cima de la Cordillera de Nahuelbuta se encontraron dos poblaciones enanas. En este trabajo se caracterizo la estructura, composicion y edades de ambas poblaciones de A. araucana y Nothofagus dombeyi como especie asociada mas importante, asi como las caracteristicas fisicas y quimicas de los suelos donde crecen. El enanismo se manifesto en ambas especies. En A. araucana los individuos raramente sobrepasaron 10 m de altura con una alta relacion diametro/altura respecto a la de arboles normales de edad similar. El crecimiento diametral anual fue < 0,12 cm para edades cercanas a 300 anos y diametros de base de alrededor de 36 cm. El desarrollo de troncos cortos con ramas extendidas y delgadas, como patas de arana, refuerza el aspecto de arboles enanos. En N. dombeyi (edades de 36 a 37 anos) el crecimiento diametral anual fue de 0,26 a 0,27 cm; la mayor parte de los individuos (60-75%) presento diametro de base < 15 cm y altura entre 1 y 6,5 m. La ubicacion topografica en la cima de la Cordillera de Nahuelbuta, sobre 1.000 m de altitud, y la exposicion abierta hacia el oceano Pacifico definen un clima de rigurosidad extrema que, junto con la escasa profundidad del suelo y pobreza de nutrientes, influyen en el bajo crecimiento, reducido tamano y formas tortuosas de los arboles.

https://scielo.conicyt.cl/pdf/bosque/v29n2/Art10.pdf

Poblaciones de araucaria enana (Araucaria araucana) en la Cordillera de Nahuelbuta, Chile

Araucaria araucana, a southern South American tree species, is considered a representative symbol of Chilean forest biodiversity due to its endemicity and longevity. An expedition to Chile and its border zone with Argentina was carried out with the aim of determining the current state of this species and to establish a tree network to study its genetic variability. Eight locations were selected across the range of distribution of the species and several experimental plots were established based on the heterogeneity within each location. Field trips revealed a high fragmentation in Araucaria forests showing low or non-existent regeneration in most of its distribution area. Experimental plots allowed the identification of severely altered areas. Moreover, 371 trees were catalogued, 193 males and 178 females. The tree network established will be very useful in future evaluations of both the ecological status of the species and its genetic resources, allowing the development of conservation strategies.

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Networking sampling of Araucaria araucana (Mol.) K. Koch in Chile and the bordering zone of Argentina: implications for the genetic resources and the sustainable management

Chilean temperate forests are dominated by Nothofagus and Araucaria araucana species. Despite A. araucana not being at imminent risk of extinction, its cultural value and the associated environmental services and landscape goods have an important role for the conservation of this native forest. In some areas, the future conservation of A. araucana is a cause of great concern given its management prohibition and regeneration limitation due to slow growth, canopy tree competition and dense understory. The above characteristics make this species most susceptible to some disturbances, such as livestock, wildlife and human pressures. Therefore, sustainable management of A. araucana forests requires the assessment of its regeneration condition. The objective of this research was to apply multivariable analysis techniques in search of the most relevant parameter for Araucaria regeneration. This study used the following methods: principal component analysis (PCA), forward stepwise regression modeling and Maxent modeling. By PCA, it was possible to reduce the dimension to six-dimensional with a variance explanation of greater than 75%. The multivariable regression model, known as model 7, was the best compromise between the coefficient of determination and model size (number of independent variables). Incorporating a maximum entropy trend improved model performance. A spatial prediction was obtained by summing the contributions of statistical methods and the geographic information system (GIS). The GIS increased the flexibility of the proposed model, which enabled an extrapolation to other areas at different spatial and temporal scales. Los bosques templados chilenos estan dominados por especies del genero Nothofagus y Araucaria araucan a. El valor cultural y los servicios y bienes ambientales asociados a la presencia de  A. araucana juegan un papel esencial en la conservacion del bosque nativo, a pesar de que no se encuentra bajo riesgo inminente de extincion. Su conservacion esta sujeta a un gran debate debido a su prohibicion de manejo y a la limitada regeneracion existente en algunas areas debido a su bajo crecimiento, la competicion existente en el dosel arboreo y la presencia de un denso sotobosque. Todas estas caracteristicas hacen a esta especie muy susceptible a perturbaciones como el ganado domestico, la fauna silvestre y la presion humana. En este sentido, el manejo sustentable de los bosques de A. araucana requiere de la evaluacion del estado de su regeneracion. El objetivo de esta investigacion fue aplicar tecnicas de analisis multivariable con objeto de encontrar los parametros mas revelantes en la regeneracion de A. araucana . Las tecnicas utilizadas fueron el Analisis de Componentes Principales (ACP), el modelo de regresion mediante la eliminacion de variables y el modelo Maxent. Mediante el analisis ACP fue posible reducir el modelo a seis variables con una explicacion de la varianza superior al 75%. El modelo de regresion multivariable, conocido como “Modelo 7”, alcanzo el mayor resultado a tenor de la relacion existente entre el coeficiente de determinacion y el tamano del modelo (numero de variables independientes). La incorporacion del concepto de maxima entropia mejoro la representatividad del modelo. La integracion de las diferentes metodologias estadisticas y los Sistemas de Informacion Geografica (SIG) permitio obtener una prediccion espacial. Los SIG incrementan la flexibilidad del modelo propuesto permitiendo su extrapolacion a otras areas bajo diferentes escalas espaciales y temporales.

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An ecophysiographic approach for Araucaria araucana regeneration management

Forest fires have increased in frequency worldwide due to global warming, drought, and land-use change. These fire-regime changes have altered the dynamics of deadwood accumulation in forests, which can affect biological communities dependent on this resource. We analyzed the effect of high-severity fire events on saproxylic beetle assemblages, which specialize in using deadwood that accumulates after disturbances. We compared assemblages in sites severely burned in 2002 to those in unburned sites in Chilean Araucaria–Nothofagus forests. Insects were collected using window-interception traps from spring 2017 to summer 2018. Rarefaction–interpolation curves revealed a significant decrease in diversity as a result of fire. Permutational multivariate analysis of variance showed a significant effect of fire on insect community structure. In addition, we observed that species turnover contributing most, and nestedness to a lesser extent, to differences in s-diversity between burned and unburned sites. Species replacement was associated with an increase in abundance of xylophagous (deadwood feeders) and a decrease in abundance of mycophagous (fungivorous) insects with fire. Therefore, our results suggest that fire causes a reduction in diversity while benefiting the abundance of xylophagous beetles in Araucaria–Nothofagus forests. We recommend the use of these insects as an evaluation tool in conservation planning, management practices, and ecological restoration efforts in burned forests in southern Chile.

Diversity loss and changes in saproxylic beetle assemblages following a high-severity fire in Araucaria–Nothofagus forests

Species Conservation and Management: Case Studies is a collection of population and metapopulation models for a wide variety of species. The chapters deal with many complexities of modeling the life history characteristics of different species in various environments, and address a variety of issues such as habitat loss, exploitation, fragmentation, diseases, pollution, habitat restoration, translocation, and connectivity. Each chapter describes how a species' life history characteristics are incorporated into the model, and how the results can be used for its conservation and management. The book includes a CD-ROM with a demo version of the RAMAS GIS program and data files for all the models.

M Gonzalez

Papers

Monkey Puzzle Tree (Araucaria araucana) in Southern Chile: effects of timber and seed harvest, volcanic activity, and fire

Variación en Araucaria araucana