Albert Reif

Effect of a tourist-ignited wildfire on Nothofagus pumilio forests at Torres del Paine biosphere reserve, Chile (Southern Patagonia)

Se describe el impacto de un incendio causado por un turista en la reserva de la biosfera Torres del Paine en el 2005 que destruyo aproximadamente 2.000 ha de bosques. Se muestran los cambios ocurridos en atributos de bosques de Nothofagus pumilio incluyendo estructura, regeneracion y composicion floristica. Se comparan tres grupos de parcelas con sitio y estructura semejantes: parcelas incendiadas (CMBP) y parcelas adyacentes no incendiadas (CMUP) del Cordon Masle, y parcelas no incendiadas de Cerro Paine (CPUP), fuera del perimetro del incendio. Se utilizo analisis no parametricos univariados (Mann-Whitney) y multivariados (MRPP e ISA). En los sitios incendiados, el fuego redujo en promedio el 91,7 % de la densidad arborea y el 70,9 % del area basal. El promedio de plantulas fue de 23.625 y 22.750 ha-1 en CPUP y CMUP, respectivamente, mientras que en CMBP se redujo a 1.125 ha-1. El dosel colapso y la cobertura y riqueza de especies de sotobosque incremento significativamente en las parcelas incendiadas. El promedio de exoticas incremento de 1,5 y 0,7 especies en CPUP y CMUP, respectivamente, hasta 11,9 especies en CMBP. La mortalidad de arboles, escasa regeneracion, invasion biologica y el colapso del dosel, estan alterando las vias sucesionales de los bosques reduciendo su capacidad de recuperacion, dificultando los esfuerzos de restauracion. Se propone a los administradores enfatizar esfuerzos en prevencion de incendios y desarrollar informacion sobre indicadores de biodiversidad para los planes de manejo, para asi conocer mas sobre la integridad ecologica de los ecosistemas y el impacto provocado por la recreacion.

The drought tolerance limit of Fagus sylvatica forest on limestone in southwestern Germany

Abstract Question: What components of drought influence the drought limit of Fagus sylvatica forests? This study contributes to the ongoing discussion regarding the future of Fagus as a major component of central European forests. Location: The drought limit of F. sylvatica at its ecotone with forest dominated by Quercus pubescens, Q. petraea and their hybrids in two limestone regions (Klettgau, Schwäbische Alb) in southwestern Germany was compared. Methods: Vegetation relevés were classified and a gradient analysis was performed. The vegetation pattern was analysed with several drought relevant variables. Classification trees were used to determine the drought limits of the Fagus forest. Results: The Fagus, Quercus and the ecotone forests were floristically characterized. The lower humidity in the submontane Klettgau, compared to the montane Schwäbische Alb, was compensated for by greater soil moisture (ASWSC). Therefore, Fagus forest in the Schwäbische Alb grew on sites with ASWSC values similar to those of ecotone forest in Klettgau. Conclusions: The interaction between climatic and edaphic drought related factors demonstrates that drought is a complex edaphic-climatic factor. Both components contribute to limiting the distribution of Fagus. For the two regions in southwestern Germany, and under the existing climatic conditions, it could be shown that Fagus is able to dominate forests on soils with very low ASWSC (≥ 68 l.m−2). Nomenclature: Oberdorfer (1994).

Solar radiation transmission in and around canopy gaps in an uneven-aged Nothofagus betuloides forest

The transmission of direct, diffuse and global solar radiation in and around canopy gaps occurring in an uneven-aged, evergreen Nothofagus betuloides forest during the growing season (October 2006–March 2007) was estimated by means of hemispherical photographs. The transmission of solar radiation into the forest was affected not only by a high level of horizontal and vertical heterogeneity of the forest canopy, but also by low angles of the sun’s path. The below-canopy direct solar radiation appeared to be variable in space and time. On average, the highest amount of transmitted direct solar radiation was estimated below the undisturbed canopy at the southeast of the gap centre. The transmitted diffuse and global solar radiation above the forest floor exhibited lower variability and, on average, both were higher at the centre of the canopy gaps. Canopy structure and stand parameters were also measured to explain the variation in the below-canopy solar radiation in the forest. The model that best fit the transmitted below-canopy direct solar radiation was a growth model, using plant area index with an ellipsoidal angle distribution as the independent variable (R2 = 0.263). Both diffuse and global solar radiation were very sensitive to canopy openness, and for both cases a quadratic model provided the best fit for these data (R2 = 0.963 and 0.833, respectively). As much as 75% and 73% of the variation in the diffuse and global solar radiation, respectively, were explained by a combination of stand parameters, namely basal area, crown projection, crown volume, stem volume, and average equivalent crown radius.

The response of ground vegetation to structural change during forest conversion in the southern Black Forest

The aim of this study is to investigate the effects of forest conversion on forest floor vegetation. ‘Ecological’ forest conversion, as defined by an interdisciplinary southern Black Forest project group, describes the transformation of even-aged spruce (Picea abies L. H. Karst.) stands to structured continuous cover forests consisting of spruce (Picea abies), silver fir (Abies alba Mill.) and beech (Fagus sylvatica L.). In order to analyse the conversion process, four conversion stages were defined in a conceptual forest development model. Four forest districts deemed to be representative of the southern Black Forest region were selected for the study. The ground vegetation was initially classified independently from the stand structures. Subsequently, the relationship between stand structures, as determined by development stage, and ground vegetation was analysed. It was revealed that forest conversion modified the ground vegetation. The main factors influencing ground vegetation were the influence of broadleaves, predominately beech (F. sylvatica), on the canopy composition and litter coverage on the one hand; and the canopy coverage of spruce, the proportion of needle litter and the associated light penetration on the other. The prevalence of moss and vascular plant species preferring acidic sites found in spruce forests decreased during the transition process, whereas, species requiring a moderate base supply increased in abundance. The continuous cover forest representing the final stage of conversion increasingly contained a mixture of ground vegetation species normally associated exclusively with either conifer or deciduous forest. Due to the fact that there is an associated ground vegetation specific to the different stages of forest conversion in stands dominated by Norway spruce or European beech and a mixture in the latest conversion stages, large-scale forest conversion should be avoided in favour of management promoting a diversity of silvicultural goals and treatments in neighbouring stands. Only a variety of treatments ensures the maintenance of floristic diversity in the long-term.

The forests of Robinson Crusoe Island, Chile: an endemism hotspot in danger

La isla Robinson Crusoe, parte del Archipielago Juan Fernandez, contiene mas especies de plantas endemicas por area que cualquier otro sistema insular en el mundo (1,9 especies/km²). Actualmente los habitats de la isla son invadidos por plantas exoticas con mayor o menor intensidad. Dos tercios de las especies de plantas vasculares se consideran en peligro de extincion, por lo que la isla representa una prioridad de conservacion para la biodiversidad a escala local y global. Utilizando informacion ya publicada, se revisan los principales tipos de vegetacion definidos para la isla Robinson Crusoe, considerando la riqueza de especies en categorias UICN (Union Internacional para la Conservacion de la Naturaleza), la cantidad de plantas exoticas invasivas y la ocurrencia de especies de aves terrestres. La mayor proporcion y numero de especies de plantas endemicas se ubicaron en el bosque montano alto y bajo de la isla, donde habitan en mayor abundancia especies de aves endemicas altamente amenazadas. Adicionalmente, para percibir necesidades de informacion para la conservacion, se analizaron los principales temas de publicaciones cientificas desarrolladas sobre el archipielago Juan Fernandez. Hasta hoy la investigacion en Juan Fernandez se ha centrado en botanica, normalmente, en temas relacionados con aspectos taxonomicos de especies de plantas singulares. Estudios en ecologia, estructura, dinamica y procesos de los bosques de la isla Robinson Crusoe han sido escasamente tratados en publicaciones cientificas. Es urgente abarcar, comprender y vincular estos temas hacia iniciativas de conservacion y restauracion aplicada.

The Vegetation of the Fichtelgebirge: Origin, Site Conditions, and Present Status

A small, horseshoe-shaped mountain range in northeastern Bavaria, the Fichtelgebirge, covers an area of about 1000 km2 (Fig. 1). The highest mountains are Ochsenkopf (1023 m a.s.l.) and Schneeberg (1053 m a.s.L; Fig. 2). “Fichtelgebirge” is related to the German word Fichte (spruce, Picea abies) and means “spruce range”.

Spatial distribution and regeneration strategies of the main forest species on Robinson Crusoe Island.

Se describe la estructura del bosque endemico de la Isla Robinson Crusoe. Se analizan las estrategias de regeneracion de los arboles: Myrceugenia fernandeziana, Fagara mayu, y Drimys confertifolia. Se inventariaron remanentes de bosque montano, con enfasis en los patrones espaciales usando la funcion K(t) de Ripley. Se hipotetiza que: i) especies ornitocoras y barocoras debieran mostrar regeneracion agrupada, a consecuencia de la lluvia de semillas; ii) si existe efecto nodriza, existira tambien un patron agregado de regeneracion; iii) en estados de desarrollo avanzado la agregacion se atenuara, a consecuencia del autorraleo; iv) si las aperturas de dosel influencian la regeneracion y mortalidad, estas presentaran patrones agrupados. M. fernandeziana fue la especie arborea mas abundante, seguida por F. mayu y D. confertifolia. La distribucion diametrica de M. fernandeziana sugirio una regeneracion continua. F. mayu exhibio una distribucion tipica de especies con regeneracion esporadica. La distribucion diametrica de D. confertifolia fue intermedia respecto a las otras especies. La regeneracion de M. fernandeziana fue espacialmente agrupada, dado su modo de dispersion (hipotesis i), pero no mostro asociacion con individuos adultos, descartandose un posible efecto nodriza (hipotesis ii). Los individuos adultos de M. fernandeziana se distribuyeron aleatoriamente probablemente debido a autorraleo (hipotesis iii). La mortalidad de adultos de M. fernandeziana no parecio responder a alteraciones locales, descartandose la hipotesis iv. F. mayu se distribuyo aleatoriamente exhibiendo, en casos, leve agregacion. D. confertifolia presento un patron agrupado. La regeneracion de F. mayu y D. confertifolia ocurrio principalmente en claros, aunque esta ultima especie se presento tambien bajo dosel. D. confertifolia tiende a regenerar cercana a ejemplares adultos de la propia especie (hipotesis ii). M. fernandeziana mostro tolerancia a la sombra, aunque es muy plastica, ocupando diferentes ambientes de regeneracion. F. mayu mostro caracteristicas de intolerante a la sombra; posiblemente requiera claros, o disturbios mayores para regenerar. D. confertifolia parece ser semitolerante a la sombra requiriendo claros, o areas con menor cobertura para establecerse.

BOSQUES DE NOTHOFAGUS BETULOIDES (MIRB.) OERST 1871 (FAGALES: NOTHOFAGACEAE) EN LA PATAGONIA AUSTRAL Y TIERRA DEL FUEGO

1 Institute of Silviculture, Faculty of Forest and Environmental Sciences, University of Freiburg, Tennenbacher Str. 4, D-79085 Freiburg, Germany*.2 Department of Silviculture, Faculty of Forest Sciences, University of Chile, Santa Rosa 11315, La Pintana, Casilla 9206, Santiago, Chile.3 Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2H1, Canada.* Corresponding author. Tel.: 0049 761 203 8622; Fax: 0049 761 203 3781. alvaro.promis@waldbau.uni-freiburg.de

Decrease in Available Soil Water Storage Capacity Reduces Vitality of Young Understorey European Beeches (Fagus sylvatica L.)—A Case Study from the Black Forest, Germany

Growth and survival of young European beech (Fagus sylvatica L.) is largely dependent on water availability. We quantified the influence of water stress (measured as Available Soil Water Storage Capacity or ASWSC) on vitality of young beech plants at a dry site. The study site was located in a semi-natural sessile oak (Quercus petraea (Mattuschka) Liebl.) stand adjacent to beech stands on a rocky gneiss outcrop in southwestern Germany. Plant vitality was measured as crown dieback and estimated by the percentage of dead above ground biomass. The magnitude of crown dieback was recorded in different vertical parts of the crown. Biomass was calculated from the harvested plants following allometric regression equations specifically developed for our study site. Stem discs from harvested plants were used for growth analysis. We found that soil depth up to bedrock and skeleton content significantly influenced ASWSC at the study site. A significant negative correlation between ASWSC and crown dieback was found. Highest rates of crown dieback were noticed in the middle and lower crown. The threshold of crown dieback as a function of drought stress for young beech plants was calculated for the first time in this study. This threshold of crown dieback was found to be 40% of above ground biomass. Beyond 40% crown dieback, plants eventually experienced complete mortality. In addition, we found that the extremely dry year of 2003 significantly hampered growth (basal area increment) of plants in dry plots (ASWSC < 61 mm) in the study area. Recovery in the plants’ radial growth after that drought year was significantly higher in less dry plots (ASWSC > 61 mm) than in dry plots. We concluded that a decrease in ASWSC impeded the vitality of young beech causing partial up to complete crown dieback in the study site.

A Traditional Cultural Landscape in Transformation

Abstract Changes in the economies, societies and politics of Europe and across the globe that have taken place since 1990 have started to impact upon ‘transition countries.’ People in the mountainous regions of Eastern Europe have begun to face completely new economic and ecological problems. The increased incorporation of rural subsistence economies into the world market will inevitably lead to socioeconomic change. Decision makers at the national and regional levels promote this process to a certain extent; yet they are in part also forced to simply follow its course. This is inducing major alterations to landscapes, brought about by increasing farm sizes and greater specialization, mechanization, and intensification on more fertile soils. Existing conflicts between over-exploitation of resources and sustainable land use await resolution. This can be achieved through the creation of new economic perspectives and with the participation of stakeholders, including politicians, government, and local people. A traditional cultural landscape in the Apuseni Mountains of Romania, its land use systems, and future perspectives for sustainable development were analyzed in the context of the Proiect Apuseni, an inter-and transdisciplinary bi-national project based in Romania and Germany. The aim of the project was to investigate the transformation processes, to identify and evaluate development strategies, and to make recommendations for sustainable regional development in participation with the local people and Romanian politicians.