The anniversary conference “Forest science for a sustainable forestry and human well-being in a changing world” - Bucharest, September 18-21 2018

Variable retention forestry conserves habitat of bird species in Patagonian Nothofagus pumilio forests

Variable retention is an alternative harvesting system that could be implemented instead the more traditional ones (e.g. shelterwood cut for N. pumilio forests in southern Patagonia), because it was designed not only for timber purpose, but also for conservation. However, the impact of different retention types on diversity is not clear, e.g. stenotopic and eurytopic bird species. The objective of this work was to analyse the habitats (inside, edge or outside of aggregated retention) and the use of strata (canopy, stem, debris and floor) for different bird species under two different variable retention harvesting types (aggregated + dispersed retentions, or ggregated retention + clear-cuts). We analysed four years of bird observation data in variable retention harvested and unharvested forest permanent plots located in Tierra del Fuego province (Argentina) belonging to PEBANPA (Parcelas de Ecología y Biodiversidad de Ambientes Naturales en Patagonia Austral) network, also with understory and crown cover data. Statistical analysis included uni- and multivariate tests, and comparisons with unharvested forests. We inventoried nine bird species, six of which showed significantly different habitat preference in variable retention types (Carduelis barbata, Phrygilus patagonicus and Tachycineta leucopyga in aggregated + dispersed retentions, and Enicognathus ferrugineus, P. patagonicus, T. leucopyga, Troglodytes aedon and Zonotrichia capensis in aggregated retention + clearcuts). Likewise, all evaluated species presented differential use of strata, and some species changed comparing harvested and unharvested forests. DCA (Detrended Corresponded Analysis) highlighted association between species and habitats (e.g. P. patagonicus is more related to outside aggregated retentions) as well as differences between variable retention types, showing that bird species move toward edges when clear-cuts were carried out, among aggregated retention, instead of dispersed retention. These results support the effectiveness of the variable retention to conserve habitat of bird species inside managed forests, which satisfy both stenotopic and eurytopic species requirements.

Monitoring of soil moisture in Long-Term Ecological Research (LTER) sites of Romanian Carpathians

Understanding soil moisture and its relationship with different climatic and soil characteristics is essential for better analysing the interactions between forest and soil water dynamics, allowing us to more precisely predict climatic changes. The present paper investigates the temporal variability of soil moisture in three different forest ecosystems (LTER – long term ecological research site) with the same soil type (Eutric Cambisol).  Soil moisture was measured daily from 2011 to 2016 by using three sensors at three different depths (20, 40, 70 cm). We identified the interactions between soil properties, vegetation type, local climatic conditions and soil moisture. In order to establish the temporal variability of the soil moisture content, we have applied two procedures, namely the Fourier series and the neural network fitting. A high variability in time and depth for soil volumetric water content was identified. The highest soil moisture levels were recorded at higher depths (70 cm) for almost all surfaces, with the exception of the Fundata surface because of the occurrence of limestone. In the mountainous areas, with higher precipitation (Fundata and Predeal sites), volumetric soil water content was mainly influenced by soil physical characteristics. Soil moisture levels below the drought level were only recorded for the Stalpeni site from September to October 2012. There was a delay between the precipitation event and soil humidification of 0.4-0.8 time units (days). We also found a significant correlation between soil moisture and soil texture and a weak correlation with vegetation type. Temperature influenced soil moisture levels at almost all depths, while precipitation only had an impact when there was a delay of 1 or 2 days. Our results can serve as a scientific base in the monitoring and analysing of soil moisture against the background of a changing climate.

Return of grey wolf (Canis lupus) to Central Europe: challenges and recommendations for future management in cultural landscapes

Grey wolf actually is immigrating Central Europe from eastern or southern populations, establishing packs and reproducing successfully. This development, starting in the beginning of the 2000s, led to an exponential
population increase until today. The present paper analyzes re-colonization of Central Europe by Grey wolf (Canis lupus), considering ecological, socio-economical as well as socio-cultural aspects, and develops basic points for an exemplary management concept. Until today, wolf management especially in Germany, Austria and Switzerland, widely follows a passive “wait and see” strategy. Thus, predations of small livestock, cattle, and horses are quickly increasing. Especially farmers and herdsmen call for a more active way of wolf management. The Central European populations of mouflon (Ovis ammon musimon), being highly endangered in its natural range, are completely disappearing with the occurrence of wolf. Hunting of wild ungulates becomes more difficult whereas forest damages by barking and browsing are not significantly reduced by the influence of wolf predation. Maintaining biodiversity by preserving open landscapes by grazing might become more and more difficult. The present paper shows the need for a more active management concept, developed from a participatory process, locally differentiated and  combining different management measures, as e.g. total protection, sustainable utilization, prevention of diseases, herd protection measures and others.

Short-term changes in plant functional traits and understory functional diversity after logging of different intensities: a temperate fir-beech forest experiment

The concept of plant functional traits has been demonstrated to be very effective in unravelling the ecological mechanisms governing plant community response to disturbance, especially when research is focused on
short-term post-disturbance vegetation dynamics. In this study, we established an experiment to quantify how logging intensity affects the trait composition and functional diversity of understory communities in fir-beech
forests in the Dinaric Mountains in Slovenia. Three different silvicultural treatments were implemented: control (no logging), 50% of the growing stock removed and 100% of the growing stock removed. Vegetation surveys of vascular plants were made before (in 2012) and two years after (in 2014) logging. Changes in species traits, C-S-R plant strategies (sensu Grime) and community-level functional diversity were analysed. The importance of traits such as small and light diaspores, short life span and anemochory increased with logging intensity. Moreover, species with the ability of both sexual and vegetative reproduction, longer flowering duration and overwintering green leaves increased in abundance after logging. C-S-R strategies mainly shifted from stress-tolerators in pre-logging conditions towards a more ruderal component in post-logging stands. Logging in the short term increased functional diversity, mainly due to newly colonized species being functionally dissimilar from persistent residents. Results suggest that logging intensity strongly influences the magnitude of change in both functional composition and diversity, which also has important implications for biodiversity conservation. At the landscape scale, increasing spatial heterogeneity by creating a mosaic of forest stands subjected to different logging intensities will likely contribute to the enhancement of plant functional diversity.