Essl Franz | Environment Agency Austria (original) (raw)

Papers by Essl Franz

1st ragweed pollen inventory for Austria, 5 km resUsing daily pollen data from 19 sites over a te... more 1st ragweed pollen inventory for Austria, 5 km resUsing daily pollen data from 19 sites over a ten year periodMapping habitats using Corine Land Cover and actual ragweed locationsUpdated methodology compared to previous methodsDirectly comparable with other inventories in EuropeThis study improves the spatial coverage of top-down Ambrosia pollen source inventories for Europe by expanding the methodology to Austria, a country that is challenging in terms of topography and the distribution of ragweed plants. The inventory combines annual ragweed pollen counts from 19 pollen-monitoring stations in Austria (2004–2013), 657 geographical observations of Ambrosia plants, a Digital Elevation Model (DEM), local knowledge of ragweed ecology and CORINE land cover information from the source area. The highest mean annual ragweed pollen concentrations were generally recorded in the East of Austria where the highest densities of possible growth habitats for Ambrosia were situated. Approximately 99% of all observations of Ambrosia populations were below 745 m. The European infection level varies from 0.1% at Freistadt in Northern Austria to 12.8% at Rosalia in Eastern Austria. More top-down Ambrosia pollen source inventories are required for other parts of Europe.A method for constructing top-down pollen source inventories for invasive ragweed plants in Austria, a country that is challenging in terms of topography and ragweed distribution.

Flora, 2009

In this paper, we analyse the patterns and determinants of cacti invasion in 22 European countrie... more In this paper, we analyse the patterns and determinants of cacti invasion in 22 European countries. We compiled a checklist for each country. Cacti were classified for each country according to their invasion status as casuals, locally established (1-5 localities of small population size) and widely established (45 localities of considerable population size).

Floristic records from eastern Upper Austria and the adjacent part of Lower Austria, Part ID New ... more Floristic records from eastern Upper Austria and the adjacent part of Lower Austria, Part ID New records of 100 rare vascular plant species are presented from eastern Upper Austria and the adjacent part of Lower Austria. Many of the species are aliens. The new localities are discussed with respect to relevant literature and the regional distribution of the species is

Basic and Applied Ecology, 2011

Invasion patterns in Europe are uneven across habitats. In particular, temperate zonal forests ar... more Invasion patterns in Europe are uneven across habitats. In particular, temperate zonal forests are relatively little affected by invasions. However, long generation periods of forest species and the rarity of disturbance events may lead to long time lags, and so, invasion resistance of temperate forests may have been overestimated.

Between 1990 and 1993 faunistic and floristic investigations were carried out in 25 gravel pits o... more Between 1990 and 1993 faunistic and floristic investigations were carried out in 25 gravel pits of various successional stages in the area of the Lower Enns and Lower Steyr rivers north of Steyr and Sierning. The authors tried to find out wether these man-made biotops offer important habitats for certain animal and plant species. The results show that 76 bird

Page 1. Beitr. Naturk. Oberösterreichs 9 507-598 2000 Fünf Jahre Begleituntersuchungen zur Wiesen... more Page 1. Beitr. Naturk. Oberösterreichs 9 507-598 2000 Fünf Jahre Begleituntersuchungen zur Wiesenpflege im Naturschutzgebiet „Staninger Leiten" (Oberösterreich, Unteres Ennstal): Projektsübersicht und Ergebnisse aus Botanik und Lepidopterologie ...

Biological Conservation, 2009

Please cite this article in press as: Essl, F., et al. Distribution patterns, range size and nich... more Please cite this article in press as: Essl, F., et al. Distribution patterns, range size and niche breadth of Austrian endemic plants.

Global Change Biology, 2010

The expected upward shift of trees due to climate warming is supposed to be a major threat to ran... more The expected upward shift of trees due to climate warming is supposed to be a major threat to range-restricted high-altitude species by shrinking the area of their suitable habitats. Our projections show that areas of endemism of five taxonomic groups (vascular plants, snails, spiders, butterflies, and beetles) in the Austrian Alps will, on average, experience a 77% habitat loss even under the weakest climate change scenario (+1.8 °C by 2100). The amount of habitat loss is positively related with the pooled endemic species richness (species from all five taxonomic groups) and with the richness of endemic vascular plants, snails, and beetles. Owing to limited postglacial migration, hotspots of high-altitude endemics are situated in rather low peripheral mountain chains of the Alps, which have not been glaciated during the Pleistocene. There, tree line expansion disproportionally reduces habitats of high-altitude species. Such legacies of climate history, which may aggravate extinction risks under future climate change have to be expected for many temperate mountain ranges.

Applied Vegetation Science, 2008

Question: Which factors determine diversity of native and alien vascular plant species in semi-na... more Question: Which factors determine diversity of native and alien vascular plant species in semi-natural dry grasslands?Location: Northern limestone Alps to the southern rim of the Bohemian massif in northern Austria.Methods: In 70 randomly chosen dry grassland patches (0.008 ha - 7 ha) we sampled a complete inventory of vascular plant species at each site. We analysed the correlation between species diversity of natives, archaeophytes (pre-1500 aliens) and neophytes (post-1500 aliens). We used GLM to study the relationship of species number (natives, neophytes, archaeophytes) to five explanatory variables (altitude, within habitat diversity, habitat diversity of adjacent areas, within land-use diversity and land-use in adjacent areas). Orthogonal components of these variables were derived with a PCA and used in the models. We also tested the influence of minimum residence time (MRT) and the covariables origin, mode of introduction and life form on the number of grassland sites with neophytes with analogous GLMs.Results: Native species diversity species was positively correlated with the species diversity of new, but not old invaders. GLM explains 70% of the variance in the number of native species. Patch size explained the largest part of the variation in the number of native species. PCA axes 1 and 3 were significantly related to the number of native species. Axis 1was related to on-site habitat and land-use diversity. The GLM of the archaeophyte diversity explains 18% of the variance. Altitude and presence of fields and grassland in the neighbourhood mainly explained archaeophyte species diversity. The GLM of neophyte diversity explains 12% of the variance. The number of neophytes was positively related to that of archaeophytes. Only PCA axis 3, which is mainly influenced by adjacent land-use types, showed a relationship with neophytes. MRT, mode of introduction and region of origin (but not life form) were significantly related to the number of grassland sites invaded by neophytes, explaining 35% of the variance.Conclusion: Most factors governing native species diversity are not significantly related to alien species diversity. Additional determinants of the local scale diversity of alien species exist such as region of origin and historical factors (MRT, mode of introduction).

Page 1. Beitr. Naturk. Oberösterreichs 4 67-126 13.12.1996 Botanisch-entomologische Begleitunters... more Page 1. Beitr. Naturk. Oberösterreichs 4 67-126 13.12.1996 Botanisch-entomologische Begleituntersuchung zu den Pflegemaßnahmen der Hangwiese im Naturschutzgebiet „Staninger Leiten" (Oberösterreich, Unteres Ennstal)1 E. HAUSER, F. ESSL & F. LICHTENBERGER2 ...

Journal for Nature Conservation

Bryophytes (Bryophyta) include mosses (Bryopsida), liverworts (Hepaticopsida) and species-poor ho... more Bryophytes (Bryophyta) include mosses (Bryopsida), liverworts (Hepaticopsida) and species-poor hornworts (Anthoceratopsida) (Söderström et al. 2002; Hill et al. 2006). Lichens are composite organisms, arising from a mutualistic association between a saprophytic fungus and a photosynthetic alga or bacterium (Ahmadjian 1993). The photosynthetic partner is usually also found as a common free-living species, and only the highly specific fungal partner is likely to be alien within Europe. Lichens are taxonomically disparate, united by common trophic strategy which has been adopted across a diverse range of fungal lineages. Lichens are distantly related to bryophytes, and biologically very different. Why therefore do we consider the two groups together in this chapter? In the context of invasions they share a number of important features which present trong practical parallels in the issues they create: (1) they are poorly recorded, so we have little information to assess their invasion history; (2) they are dispersed efficiently by spores, and have much greater natural colonizing ability than other major taxa; (3) since they have few cultivated uses there is a near-absence of deliberate introductions; (4) being small organisms and rarely parasitic, their impacts tend to be measurable only on a micro-scale (5) the possibility of subtle but long-term effects of such invasions has yet to be considered by the scientific community.

Floristic observations from the eastern Upper Austrian alpine foothills II Abstract: For 26 rare ... more Floristic observations from the eastern Upper Austrian alpine foothills II Abstract: For 26 rare or decreasing species new localities in the eastern Upper Austrian foothills and a few new localities in the western area of Lower Austria are reported. Most of them are species of segetal and ruderal habitats (Amaranlhus albus, Bromus secalinus, Camelina microcarpa, Chenopodium botrys, Ch. bonus-henricus, Ch. glaucum, Duchnesea indica, Panicum dichotomiflorum, P. miliaceum, Polycnemum majus, Rumex thyrsiflorus, Sedum sarmentosum, Tragopogon dubium), some are species of riverside forests and mixed forests and their edges (Phytolacca esculenta, Bryonia dioica, Cucubalus baccifer, Dipsacus pilosus, Doronicum pardalianches, Polygonatum verticillatum, Serratula tinctoria), wet habitats (Bolboschoenus maritimus, Carex disticha, Mimulus guttatus, Rumex maritimus, Sagina nodosa) and dry habitats (Artemisia campestris). Polygonatum verticillatum is widely distributed within the Alps but its discovery in two remote localities in the foothills is a rare exception. Especially remarkable are the new localities which concern species either threatened with extinction or seriously endangered within Upper Austria. These species are: Bolboschoenus maritimus, which was thought to be extinct in Upper Austria and was recorded at two sites along the Ennsriver. Sagina nodosa, Serratula tinctoria, Carex disticha, Bromus secalinus, Polycnemum majus and Cucubalus baccifer are seriously endangered species in Upper Austria. A great proportion of aforementione d species are neophytes (Amaranthus albus, Amaranthus botrys, Doronicum pardalianches, Duchnesea indica, Mimulus guttatus, Panicum dichotomiflorum, Phytolacca esculenta, Sedum sarmentosum). The short but tremendously fast-progressing spreading history of Panicum dichotomiflorum is sketched. Duchesnea indica has in the meantime been rated as a permanent part of the upper Austrian flora. New aliens for the flora of Upper Austria are Doronicum pardalianches (locally established) and Sedum sarmentosum (casual). Dot maps of the local distribution of the species discussed are given.

The distribution of Aster amellus, Geranium sanguineum, Muscari comosum, Pseudolysimachion spicat... more The distribution of Aster amellus, Geranium sanguineum, Muscari comosum, Pseudolysimachion spicatum and Sorbus torminalis in Upper Austria The distribution of five vascular plant species growing in dry and warm meadows and woods in the lower parts of Upper Austria is presented and discussed. By using old literature and herbarium material it can be shown that Aster amellus, Geranium sanguineum, Muscari

Proceedings of The National Academy of Sciences, 2010

The accelerating rates of international trade, travel, and transport in the latter half of the tw... more The accelerating rates of international trade, travel, and transport in the latter half of the twentieth century have led to the progressive mixing of biota from across the world and the number of species introduced to new regions continues to increase. The importance of biogeographic, climatic, economic, and demographic factors as drivers of this trend is increasingly being realized but as yet there is no consensus regarding their relative importance. Whereas little may be done to mitigate the effects of geography and climate on invasions, a wider range of options may exist to moderate the impacts of economic and demographic drivers. Here we use the most recent data available from Europe to partition between macroecological, economic, and demographic variables the variation in alien species richness of bryophytes, fungi, vascular plants, terrestrial insects, aquatic invertebrates, fish, amphibians, reptiles, birds, and mammals. Only national wealth and human population density were statistically significant predictors in the majority of models when analyzed jointly with climate, geography, and land cover. The economic and demographic variables reflect the intensity of human activities and integrate the effect of factors that directly determine the outcome of invasion such as propagule pressure, pathways of introduction, eutrophication, and the intensity of anthropogenic disturbance. The strong influence of economic and demographic variables on the levels of invasion by alien species demonstrates that future solutions to the problem of biological invasions at a national scale lie in mitigating the negative environmental consequences of human activities that generate wealth and by promoting more sustainable population growth. climate | economy | exotic plants and animals | geography | prediction

Botanica Helvetica, 2005

Essl F. 2005. Spread and incipient naturalization of Spiraea japonica in Austria. Bot. Helv. 115:... more Essl F. 2005. Spread and incipient naturalization of Spiraea japonica in Austria. Bot. Helv. 115: 1–14. The subspontaneous spread and incipient naturalization of the alien Japanese honeysuckle (Spiraea japonica) in Austria were studied by reviewing floristic literature and by surveying a 3-km2 area in the alpine foothills of eastern Upper Austria between 1990 and 2004. The literature review shows that the abundance and range of Spiraea japonica have increased in Austria during the 20th century: Until 1945, the species had been recorded in only three mapping units (c. 30 km2) of the floristic mapping project of Austria. Between 1945 and 1990, it was found in seven mapping units, and since 1991, in a total of 20 mapping units. In the field survey, 50 individuals of Spiraea japonica were recorded in 1990, but 198 in 2004. The species mainly occurred in climax forests (Galio sylvatici-Carpinetum) and pioneer forests (Sambucetum racemosae) dominated by Betula pendula; it was less frequent in pine or spruce plantations. No detrimental effects on native plants could be observed. Nevertheless, the further expansion of Spiraea japonica in Central Europe should be monitored attentively as this species is considered invasive in parts of North America.

1st ragweed pollen inventory for Austria, 5 km resUsing daily pollen data from 19 sites over a te... more 1st ragweed pollen inventory for Austria, 5 km resUsing daily pollen data from 19 sites over a ten year periodMapping habitats using Corine Land Cover and actual ragweed locationsUpdated methodology compared to previous methodsDirectly comparable with other inventories in EuropeThis study improves the spatial coverage of top-down Ambrosia pollen source inventories for Europe by expanding the methodology to Austria, a country that is challenging in terms of topography and the distribution of ragweed plants. The inventory combines annual ragweed pollen counts from 19 pollen-monitoring stations in Austria (2004–2013), 657 geographical observations of Ambrosia plants, a Digital Elevation Model (DEM), local knowledge of ragweed ecology and CORINE land cover information from the source area. The highest mean annual ragweed pollen concentrations were generally recorded in the East of Austria where the highest densities of possible growth habitats for Ambrosia were situated. Approximately 99% of all observations of Ambrosia populations were below 745 m. The European infection level varies from 0.1% at Freistadt in Northern Austria to 12.8% at Rosalia in Eastern Austria. More top-down Ambrosia pollen source inventories are required for other parts of Europe.A method for constructing top-down pollen source inventories for invasive ragweed plants in Austria, a country that is challenging in terms of topography and ragweed distribution.

Flora, 2009

In this paper, we analyse the patterns and determinants of cacti invasion in 22 European countrie... more In this paper, we analyse the patterns and determinants of cacti invasion in 22 European countries. We compiled a checklist for each country. Cacti were classified for each country according to their invasion status as casuals, locally established (1-5 localities of small population size) and widely established (45 localities of considerable population size).

Floristic records from eastern Upper Austria and the adjacent part of Lower Austria, Part ID New ... more Floristic records from eastern Upper Austria and the adjacent part of Lower Austria, Part ID New records of 100 rare vascular plant species are presented from eastern Upper Austria and the adjacent part of Lower Austria. Many of the species are aliens. The new localities are discussed with respect to relevant literature and the regional distribution of the species is

Basic and Applied Ecology, 2011

Invasion patterns in Europe are uneven across habitats. In particular, temperate zonal forests ar... more Invasion patterns in Europe are uneven across habitats. In particular, temperate zonal forests are relatively little affected by invasions. However, long generation periods of forest species and the rarity of disturbance events may lead to long time lags, and so, invasion resistance of temperate forests may have been overestimated.

Between 1990 and 1993 faunistic and floristic investigations were carried out in 25 gravel pits o... more Between 1990 and 1993 faunistic and floristic investigations were carried out in 25 gravel pits of various successional stages in the area of the Lower Enns and Lower Steyr rivers north of Steyr and Sierning. The authors tried to find out wether these man-made biotops offer important habitats for certain animal and plant species. The results show that 76 bird

Page 1. Beitr. Naturk. Oberösterreichs 9 507-598 2000 Fünf Jahre Begleituntersuchungen zur Wiesen... more Page 1. Beitr. Naturk. Oberösterreichs 9 507-598 2000 Fünf Jahre Begleituntersuchungen zur Wiesenpflege im Naturschutzgebiet „Staninger Leiten" (Oberösterreich, Unteres Ennstal): Projektsübersicht und Ergebnisse aus Botanik und Lepidopterologie ...

Biological Conservation, 2009

Please cite this article in press as: Essl, F., et al. Distribution patterns, range size and nich... more Please cite this article in press as: Essl, F., et al. Distribution patterns, range size and niche breadth of Austrian endemic plants.

Global Change Biology, 2010

The expected upward shift of trees due to climate warming is supposed to be a major threat to ran... more The expected upward shift of trees due to climate warming is supposed to be a major threat to range-restricted high-altitude species by shrinking the area of their suitable habitats. Our projections show that areas of endemism of five taxonomic groups (vascular plants, snails, spiders, butterflies, and beetles) in the Austrian Alps will, on average, experience a 77% habitat loss even under the weakest climate change scenario (+1.8 °C by 2100). The amount of habitat loss is positively related with the pooled endemic species richness (species from all five taxonomic groups) and with the richness of endemic vascular plants, snails, and beetles. Owing to limited postglacial migration, hotspots of high-altitude endemics are situated in rather low peripheral mountain chains of the Alps, which have not been glaciated during the Pleistocene. There, tree line expansion disproportionally reduces habitats of high-altitude species. Such legacies of climate history, which may aggravate extinction risks under future climate change have to be expected for many temperate mountain ranges.

Applied Vegetation Science, 2008

Question: Which factors determine diversity of native and alien vascular plant species in semi-na... more Question: Which factors determine diversity of native and alien vascular plant species in semi-natural dry grasslands?Location: Northern limestone Alps to the southern rim of the Bohemian massif in northern Austria.Methods: In 70 randomly chosen dry grassland patches (0.008 ha - 7 ha) we sampled a complete inventory of vascular plant species at each site. We analysed the correlation between species diversity of natives, archaeophytes (pre-1500 aliens) and neophytes (post-1500 aliens). We used GLM to study the relationship of species number (natives, neophytes, archaeophytes) to five explanatory variables (altitude, within habitat diversity, habitat diversity of adjacent areas, within land-use diversity and land-use in adjacent areas). Orthogonal components of these variables were derived with a PCA and used in the models. We also tested the influence of minimum residence time (MRT) and the covariables origin, mode of introduction and life form on the number of grassland sites with neophytes with analogous GLMs.Results: Native species diversity species was positively correlated with the species diversity of new, but not old invaders. GLM explains 70% of the variance in the number of native species. Patch size explained the largest part of the variation in the number of native species. PCA axes 1 and 3 were significantly related to the number of native species. Axis 1was related to on-site habitat and land-use diversity. The GLM of the archaeophyte diversity explains 18% of the variance. Altitude and presence of fields and grassland in the neighbourhood mainly explained archaeophyte species diversity. The GLM of neophyte diversity explains 12% of the variance. The number of neophytes was positively related to that of archaeophytes. Only PCA axis 3, which is mainly influenced by adjacent land-use types, showed a relationship with neophytes. MRT, mode of introduction and region of origin (but not life form) were significantly related to the number of grassland sites invaded by neophytes, explaining 35% of the variance.Conclusion: Most factors governing native species diversity are not significantly related to alien species diversity. Additional determinants of the local scale diversity of alien species exist such as region of origin and historical factors (MRT, mode of introduction).

Page 1. Beitr. Naturk. Oberösterreichs 4 67-126 13.12.1996 Botanisch-entomologische Begleitunters... more Page 1. Beitr. Naturk. Oberösterreichs 4 67-126 13.12.1996 Botanisch-entomologische Begleituntersuchung zu den Pflegemaßnahmen der Hangwiese im Naturschutzgebiet „Staninger Leiten" (Oberösterreich, Unteres Ennstal)1 E. HAUSER, F. ESSL & F. LICHTENBERGER2 ...

Journal for Nature Conservation

Bryophytes (Bryophyta) include mosses (Bryopsida), liverworts (Hepaticopsida) and species-poor ho... more Bryophytes (Bryophyta) include mosses (Bryopsida), liverworts (Hepaticopsida) and species-poor hornworts (Anthoceratopsida) (Söderström et al. 2002; Hill et al. 2006). Lichens are composite organisms, arising from a mutualistic association between a saprophytic fungus and a photosynthetic alga or bacterium (Ahmadjian 1993). The photosynthetic partner is usually also found as a common free-living species, and only the highly specific fungal partner is likely to be alien within Europe. Lichens are taxonomically disparate, united by common trophic strategy which has been adopted across a diverse range of fungal lineages. Lichens are distantly related to bryophytes, and biologically very different. Why therefore do we consider the two groups together in this chapter? In the context of invasions they share a number of important features which present trong practical parallels in the issues they create: (1) they are poorly recorded, so we have little information to assess their invasion history; (2) they are dispersed efficiently by spores, and have much greater natural colonizing ability than other major taxa; (3) since they have few cultivated uses there is a near-absence of deliberate introductions; (4) being small organisms and rarely parasitic, their impacts tend to be measurable only on a micro-scale (5) the possibility of subtle but long-term effects of such invasions has yet to be considered by the scientific community.

Floristic observations from the eastern Upper Austrian alpine foothills II Abstract: For 26 rare ... more Floristic observations from the eastern Upper Austrian alpine foothills II Abstract: For 26 rare or decreasing species new localities in the eastern Upper Austrian foothills and a few new localities in the western area of Lower Austria are reported. Most of them are species of segetal and ruderal habitats (Amaranlhus albus, Bromus secalinus, Camelina microcarpa, Chenopodium botrys, Ch. bonus-henricus, Ch. glaucum, Duchnesea indica, Panicum dichotomiflorum, P. miliaceum, Polycnemum majus, Rumex thyrsiflorus, Sedum sarmentosum, Tragopogon dubium), some are species of riverside forests and mixed forests and their edges (Phytolacca esculenta, Bryonia dioica, Cucubalus baccifer, Dipsacus pilosus, Doronicum pardalianches, Polygonatum verticillatum, Serratula tinctoria), wet habitats (Bolboschoenus maritimus, Carex disticha, Mimulus guttatus, Rumex maritimus, Sagina nodosa) and dry habitats (Artemisia campestris). Polygonatum verticillatum is widely distributed within the Alps but its discovery in two remote localities in the foothills is a rare exception. Especially remarkable are the new localities which concern species either threatened with extinction or seriously endangered within Upper Austria. These species are: Bolboschoenus maritimus, which was thought to be extinct in Upper Austria and was recorded at two sites along the Ennsriver. Sagina nodosa, Serratula tinctoria, Carex disticha, Bromus secalinus, Polycnemum majus and Cucubalus baccifer are seriously endangered species in Upper Austria. A great proportion of aforementione d species are neophytes (Amaranthus albus, Amaranthus botrys, Doronicum pardalianches, Duchnesea indica, Mimulus guttatus, Panicum dichotomiflorum, Phytolacca esculenta, Sedum sarmentosum). The short but tremendously fast-progressing spreading history of Panicum dichotomiflorum is sketched. Duchesnea indica has in the meantime been rated as a permanent part of the upper Austrian flora. New aliens for the flora of Upper Austria are Doronicum pardalianches (locally established) and Sedum sarmentosum (casual). Dot maps of the local distribution of the species discussed are given.

The distribution of Aster amellus, Geranium sanguineum, Muscari comosum, Pseudolysimachion spicat... more The distribution of Aster amellus, Geranium sanguineum, Muscari comosum, Pseudolysimachion spicatum and Sorbus torminalis in Upper Austria The distribution of five vascular plant species growing in dry and warm meadows and woods in the lower parts of Upper Austria is presented and discussed. By using old literature and herbarium material it can be shown that Aster amellus, Geranium sanguineum, Muscari

Proceedings of The National Academy of Sciences, 2010

The accelerating rates of international trade, travel, and transport in the latter half of the tw... more The accelerating rates of international trade, travel, and transport in the latter half of the twentieth century have led to the progressive mixing of biota from across the world and the number of species introduced to new regions continues to increase. The importance of biogeographic, climatic, economic, and demographic factors as drivers of this trend is increasingly being realized but as yet there is no consensus regarding their relative importance. Whereas little may be done to mitigate the effects of geography and climate on invasions, a wider range of options may exist to moderate the impacts of economic and demographic drivers. Here we use the most recent data available from Europe to partition between macroecological, economic, and demographic variables the variation in alien species richness of bryophytes, fungi, vascular plants, terrestrial insects, aquatic invertebrates, fish, amphibians, reptiles, birds, and mammals. Only national wealth and human population density were statistically significant predictors in the majority of models when analyzed jointly with climate, geography, and land cover. The economic and demographic variables reflect the intensity of human activities and integrate the effect of factors that directly determine the outcome of invasion such as propagule pressure, pathways of introduction, eutrophication, and the intensity of anthropogenic disturbance. The strong influence of economic and demographic variables on the levels of invasion by alien species demonstrates that future solutions to the problem of biological invasions at a national scale lie in mitigating the negative environmental consequences of human activities that generate wealth and by promoting more sustainable population growth. climate | economy | exotic plants and animals | geography | prediction

Botanica Helvetica, 2005

Essl F. 2005. Spread and incipient naturalization of Spiraea japonica in Austria. Bot. Helv. 115:... more Essl F. 2005. Spread and incipient naturalization of Spiraea japonica in Austria. Bot. Helv. 115: 1–14. The subspontaneous spread and incipient naturalization of the alien Japanese honeysuckle (Spiraea japonica) in Austria were studied by reviewing floristic literature and by surveying a 3-km2 area in the alpine foothills of eastern Upper Austria between 1990 and 2004. The literature review shows that the abundance and range of Spiraea japonica have increased in Austria during the 20th century: Until 1945, the species had been recorded in only three mapping units (c. 30 km2) of the floristic mapping project of Austria. Between 1945 and 1990, it was found in seven mapping units, and since 1991, in a total of 20 mapping units. In the field survey, 50 individuals of Spiraea japonica were recorded in 1990, but 198 in 2004. The species mainly occurred in climax forests (Galio sylvatici-Carpinetum) and pioneer forests (Sambucetum racemosae) dominated by Betula pendula; it was less frequent in pine or spruce plantations. No detrimental effects on native plants could be observed. Nevertheless, the further expansion of Spiraea japonica in Central Europe should be monitored attentively as this species is considered invasive in parts of North America.