Search results for "forestry"

Nutrient element and carbohydrate status of Norway spruce at Mt. Kleiner Feldberg in Taunus exposed to air pollution and soil acidification

1988

The fall and the fragmentation of national clusters: Cluster evolution in the paper and pulp industry

2012

Abstract A common expectation in evolutionary cluster studies is that national clusters engage in competitive interactions that lead to a continuous stream of changes in global dominance. Our fuzzy-set analysis on the evolution of the paper and pulp industry demonstrates that globalization has dramatically changed this situation. National clusters have largely faded away; the value chain dominance is now held by technology suppliers who are global hubs in majority of identifiable business activities in the focal industry. Our results imply that when industrial decline is accentuated by industrial concentration in some part of the value chain the national clusters may lose their importance.

The impact of economic, social and political factors on the landscape structure of the Vidzeme Uplands in Latvia

2005

Abstract Changes in landscape structure in a typical part of the Vidzeme Uplands in central Latvia during the 20th century are analysed and anticipated changes in the 21st century are projected. Forest areas gradually increased in the Vidzeme Uplands over the course of the 20th century. This increase was associated with several factors: the economic policy in Latvia during the 1930s, the exile of farmers in 1940 and 1949 after the Soviet occupation of Latvia, the aggregation of land into collective farms, the amalgamation of small collective farms, the formation of large-scale Soviet collective farms, and widespread land melioration. Since land reform in the 1990s, following the restoration…

Assessment of site-specific drivers of farmland abandonment in mosaic-type landscapes: A case study in Vidzeme, Latvia

2018

Abstract Farmland abandonment, which causes changes in rural life and farming practices, can be observed throughout Europe. Over the last decades natural afforestation has decreased the area of farmland used for agricultural production, thereby leading to landscape homogenization and polarization. This process is explicitly evident in mosaic type landscapes consisting of highly complex land cover patterns, soil composition and topography. The aim of the study was to determine the site-specific driving forces of farmland abandonment at landscape scale in relation to agro-ecological and geographic factors, in a post-Soviet country in Eastern Europe. An extensive field survey approach with sta…

Relationships between climatic parameters and forest vegetation: application to burned area in Alicante (Spain)

2000

Abstract The main aims of this study is to examine the variability of normalized difference vegetation index (NDVI) on forest vegetation in Alicante (Spain) between 1984 and 1994 and to analyse the influence of climatic parameters in the regeneration of forest areas burned by fires. The zone of study is located between XUTM (m) 730400-760400 and YUTM (m) 4274000-4304000 and is characterised by a great topographic complexity that leads to diverse microclimatic conditions. In this area, the maximum annual rainfall of the Valencian Community is recorded, reaching 850 mm of average annual rainfall ( Belda, 1997 ). We examined the spatial and temporal analyse of rainfall and soil moisture over t…

Photosynthesis and transpiration of healthy and diseased spruce trees in the course of three vegetation periods

1988

CO2- and H2O-gas exchange of 20- to 25-year-old spruce trees from a plantation in the Hunsruck mountains were investigated over a period of 3 years. All measurements were made as pair comparisons, i.e., in each case the gas exchange of a damaged tree and of a relatively healthy tree in its immediate vicinity was measured simultaneously. A second plantation in the Westerwald mountains consisted of 18-year-old apparently healthy spruce trees. Pair comparison at this location meant comparison of two healthylooking trees. The investigations at both locations included diurnal course measurements of photosynthesis and transpiration, and light saturation curves and CO2-saturation curves of photosy…

A new association of relict maquis with Ptilostemon greuteri (Oleo-Ceratonion, Quercetea ilicis), located in a circumscribed area of north-western Si…

2022

This paper illustrates the results of a survey aimed at deepening available knowledge on the ecology of Ptilostemon greuteri (Asteraceae), a very rare palaeoendemic and relict nano-phanerophyte discovered about 15 years ago on Monte Inici, near Castellammare del Golfo (province of Trapani, north-western Sicily). Two plant communities characterised by P. greuteri are described in detail; they occur in the locus classicus and in a second, recently discovered stand, which is also very localised and threatened by fire. The field investigations revealed that the sites where the species grows are very similar from the ecological point of view; in fact, both of them are located on the steep slopes…

Relevant habitats neglected by the Directive 92/43 EEC: the contribution of Vegetation Science for their reappraisal in Sicily

2021

Field investigation carried out by the Sicilian botanists in the last 20 years enabled them to identify eight habitat types of high biogeographic and conservation interest, neglected by the Directive 92/43, which deservead hocconservation measures. For each of these habitats, a syntaxonomic interpretation of the corresponding plant communities, their main ecological, physiognomic and syndynamic traits and a list of diagnostic species are provided. Their classification into the macrotypes listed in the Annex I of the Directive 92/43 and the respective correspondence in EUNIS habitat classification are proposed. The habitats here described integrate those already proposed by the Italian Botan…

Role of the Siberian flying squirrel as an umbrella species for biodiversity in northern boreal forests

2008

Abstract One of the potentially useful indirect shortcut methods in biodiversity conservation is the umbrella species concept. An umbrella species can be seen relatively demanding for the size of the area and probably also for certain habitat types: conservation management for the umbrella species would thus encompass other species preferring similar habitats but with smaller area requirements. As such, it has a comprehensive spatial aspect for landscape planning. We tested the role of the Siberian flying squirrel ( Pteromys volans ) as an umbrella species for wood dependent species among red-listed and old-growth forest associated polypores, epiphytic lichens and beetles. Flying squirrels …

Evaluation, Analysis and Perception of Sustainable Forest Management Through the Lens of the PEFC Forest Certification Using Two Case Studies in Sici…

2019

Sustainable forest management has reached a common understanding between scientific and technical definitions. A series of criteria and indicators have been implemented for monitoring the effectiveness of the management in functional and structural terms, and to evaluate its effects on ecosystem services of forests. Currently, Sicily has no forest areas with certification of sustainable forest management and in order to evaluate the diffusion of knowledge of certification schemes and their importance in SFM, a questionnaire survey was carried out during a foresters' workshop on the island. The possibility of applying the criteria and indicators of PEFC certification of sustainable forest ma…