101,925 research outputs found
Abies – Circum-Mediterranean firs in Europe: distribution, habitat, usage and threats
Most European firs occur predominantly in small to medium-sized populations in the Mediterranean region, sometimes with fragmented and limited distributions, except for silver fir (Abies alba). They all are genetically closely related and can easily hybridise, perhaps as a consequence of late speciation during the late Quaternary. Circum-Mediterranean firs occur principally in mountain areas with medium to high precipitations rates which are mostly concentrated during the winter period. The species are able to tolerate long droughts in summer and tend to form pure stands when in optimal habitats. In the past firs have been extensively logged for construction and fire wood and their stands were replaced by other more disturbance adapted species or converted into rural areas. Nowadays with the exception of silver fir and Caucasian fir (Abies nordmanniana), circum-Mediterranean firs do not have a wide commercial interest. In Turkey they are still exploited for timber wood, while other firs have an ornamental use in gardening. Great importance is given to their preservation, especially to those populations which have very limited areas and specimens, with the creation of protected reserves and conservation programmes. Wild fires, livestock grazing and genetic drift represent actually their main threats
Robinia pseudoacacia in Europe: distribution, habitat, usage and threats
Robinia pseudoacacia L., commonly known as black locust, is a tree native to North America and is one of the most important and widespread broadleaved alien trees in Europe. It is a medium-sized, deciduous, fast-growing thorny tree with high suckering capacity. It has been extensively planted in Europe and now it is naturalised in practically the whole continent. Growing on a wide range of soil types, this tree species only avoids wet or compacted conditions. It is mainly distributed in sub-Mediterranean to warm continental climates and requires a rather high heat-sum. As a light-demanding pioneer species, it rapidly colonises grasslands, semi-natural woodlands and urban habitats, where it can persist for a long time. Owing to the capacity of fixing di-nitrogen through symbiotic rhizobia in root nodules, black locust can add high rates of nitrogen to soil which becomes available to other plants. The wood of black locust is durable and rot-resistant, making it adequate for multiple purposes such as fire and pulp wood, for fences, construction and furniture. In several parts of Europe, black locust is considered an invasive alien plant, because of shading and its ability to change soil conditions
Picea abies in Europe: distribution, habitat, usage and threats
Among the coniferous species, Norway spruce (Picea abies (L.) Karst.) is one of the most important trees in Europe both for economic and ecological aspects, with a long tradition of cultivation. It can be a big tree, reaching 50-60 m in height with a straight and regular trunk, particularly used for timber constructions, pulpwood for paper and furniture. This widespread species dominates the Boreal forests in Northern Europe and the subalpine areas of the Alps and Carpathian Mountains. Thanks to its high performances in different site conditions, it can also be found outside its natural distribution on lower elevations in more temperate forests. Norway spruce has been massively planted up to its niche limits, where it is particularly susceptible to heat and drought, due to its shallow root system. For this reason it is expected to be severely affected under global warming conditions. Disturbed and weakened plants can be easily attacked by rot fungi such as Heterobasidion annosum and Armillaria, or by the bark beetles Ips typographus, one of the most destructive spruce forest pests
Chorological data for the main European woody species
The data are organized as a set of ESRI shapefiles (*.shp, *.shx, *.dbf, *.prj files) mapping the distribution ranges of the main European tree and shrub species. For each species and in some cases subspecies, one or more shapefiles have been created containing: a) polygon features (name suffix “plg”), which define continuous areas of occupancy of the species range and b) point features (name suffix “pnt”), which identify more fragmented and isolated populations. For species with reported synanthropic occurrences outside the natural range, an additional point and/or polygon shapefile has also been created (suffix “syn”). Polygon borders delimiting species ranges are generalized across the mainland and sea boundaries. This offers the possibility to mask sea areas or to clip and extract the terrestrial range parts using GIS data layers of the users' choice. An additional version of polygon ranges are clipped with a coastline (name suffix “clip”), which have been derived from Natural Earth dataset "Admin 0 - Countries" 1:50M version 4.1.0 (https://www.naturalearthdata.com). Finally, an accompanying text document is included with the data, which provides more details on methodology and a list of all mapped species with related file names, taxonomical delimitation of the mapped species and references used to compile the respective chorological dataset
Chorological data for the main European woody species
The data are organized as a set of ESRI shapefiles (*.shp, *.shx, *.dbf, *.prj files) mapping the distribution ranges of the main European tree and shrub species. For each species and in some cases subspecies, one or more shapefiles have been created containing: a) polygon features (name suffix “plg”), which define continuous areas of occupancy of the species range and b) point features (name suffix “pnt”), which identify more fragmented and isolated populations. For species with reported synanthropic occurrences outside the natural range, an additional point and/or polygon shapefile has also been created (suffix “syn”). Polygon borders delimiting species ranges are generalized across the mainland and sea boundaries. This offers the possibility to mask sea areas or to clip and extract the terrestrial range parts using GIS data layers of the users' choice. An additional version of polygon ranges are clipped with a coastline (name suffix “clip”), which have been derived from Natural Earth dataset "Admin 0 - Countries" 1:50M version 4.1.0 (https://www.naturalearthdata.com). Finally, an accompanying text document is included with the data, which provides more details on methodology and a list of all mapped species with related file names, taxonomical delimitation of the mapped species and references used to compile the respective chorological dataset
Chorological data for the main European woody species
The data are organized as a set of ESRI shapefiles (*.shp, *.shx, *.dbf, *.prj files) mapping the distribution ranges of the main European tree and shrub species. For each species and in some cases subspecies, one or more shapefiles have been created containing: a) polygon features (name suffix “plg”), which define continuous areas of occupancy of the species range and b) point features (name suffix “pnt”), which identify more fragmented and isolated populations. For species with reported synanthropic occurrences outside the natural range, an additional point and/or polygon shapefile has also been created (suffix “syn”). Polygon borders delimiting species ranges are generalized across the mainland and sea boundaries. This offers the possibility to mask sea areas or to clip and extract the terrestrial range parts using GIS data layers of the users' choice. An additional version of polygon ranges are clipped with a coastline (name suffix “clip”), which have been derived from Natural Earth dataset "Admin 0 - Countries" 1:50M version 4.1.0 (https://www.naturalearthdata.com). Finally, an accompanying text document is included with the data, which provides more details on methodology and a list of all mapped species with related file names, taxonomical delimitation of the mapped species and references used to compile the respective chorological dataset
Betula pendula, Betula pubescens and other birches in Europe: distribution, habitat, usage and threats
Silver birch (Betula pendula Roth) and downy birch (Betula pubescens Ehrh.) are short-lived, relatively small broadleaved trees that occur throughout most of Europe, particularly in northern regions. In southern Europe, birch trees are confined to mountainous areas, as they do not tolerate prolonged summer drought. Birch has a light canopy of small serrated leaves, and characteristic smooth, white to grey bark. In northern regions, birch trees can dominate the landscape up to the tree-line, whereas in the centre of their range they often occur early in secondary succession because of their abundant seed production, low demands on soil quality, and intolerance of shade. Birch trees provide the predominant hard wood source in northern Europe, and some varieties of Betula pendula produce highly priced veneers, while Betula pubescens is mostly used for pulp and fire wood. Other rarer species of birch are endemic to Europe contributing to the continental biodiversity even at high elevations and latitudes
Larix decidua and other larches in Europe: distribution, habitat, usage and threats
The European larch (Larix decidua Mill.) is a pioneer, very long-lived, fast-growing coniferous tree, which occurs in the central and eastern mountains of Europe, forming open forests or pasture woods at the upper tree limits. Larch is the only deciduous conifer in Europe as an adaptation to continental alpine climates. In fact, it is able to tolerate very cold temperatures during winter and, by losing its needles, avoids foliage desiccation. It is a transitional species, colonising open terrain after natural disturbances. It forms pure stands but more often it is found with other alpine tree species, which tend to replace it if no other disturbances occur. Thanks to its adaptability and the durability of its wood, the European larch represents an important silvicultural tree species in the alpine regions, planted even outside its natural ranges. Its wood is largely used for carpentry, furniture and pulp for paper. In lower altitudes or with high precipitation rates, larch is more susceptible to fungal diseases. Outbreaks of insect defoliators, principally caused by the larch bud moth (Zeiraphera diniana), can limit tree development, with economic losses in plantations, but they rarely lead to the death of the trees
Juglans regia in Europe: distribution, habitat, usage and threats
Juglans regia L., commonly known as common, English or Persian walnut, is an economically very important tree species, prized both for its nuts and for its attractive high-quality timber. It is the most widespread nut tree worldwide
Castanea sativa in Europe: distribution, habitat, usage and threats
The sweet chestnut (Castanea sativa Mill.) is the only native species of the genus in Europe. The broad diffusion and active management by man resulted in the establishment of the species at the limits of its potential ecological range, which makes it difficult to trace its original natural area. The present distribution ranges from North-Western Africa (e.g. Morocco) to North-Western Europe (southern England, Belgium) and from south-western Asia (e.g. Turkey) to Eastern Europe (e.g. Romania), the Caucasus (Georgia, Armenia) and the Caspian Sea. In Europe the main chestnut forests are concentrated in a few countries such as Italy, France and the Iberian Peninsula. The sweet chestnut has a remarkable multipurpose character, and may be managed for timber production (coppice and high forest) as well as for fruit production (traditional orchards), including a broad range of secondary products and ecosystem services
- …
