Risk analysis of potential invasive plants in Spain

Andreu J., Vilà M. (2010) Risk analysis of potential invasive plants in Spain. Journal for Nature Conservation. 18: 34-44.
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Doi: 10.1016/j.jnc.2009.02.002

Resum:

Once non-native species become established in a new region, they are extremely difficult to eradicate or control, suggesting an urgent need for the development of early warning systems to determine the probability of a given species becoming invasive. Risk assessment schemes are valuable tools to diminish the risk of invasion and to concentrate resources on preventing the entrance and spread of those species with higher risk of invasion. For many European countries, plant species not yet introduced to the country and with high invasive potential have not been identified. The present study aims to identify and rank non-native plant species that could potentially become invasive in Spain if introduced. As a first step, a plant data set was pre-selected for screening, containing invasive plants in neighbouring countries and in other Mediterranean regions of the world but not present in Spain. A preliminary list of 80 species was obtained, Leguminosae being the most represented family (15%) and gardening (62%) the most common pathway of introduction. As for the potential European Nature Information System (EUNIS) habitats to invade, heath land and scrubland habitats types (F; 19%), followed by constructed, industrial and artificial habitats (J; 14%) and woodland and forest habitats (G; 13%) seem to be the habitats most at risk despite F and G habitats currently being the least invaded in Spain. We ranked these potential invasive species using the Australian Weed Risk Assessment system and a Risk Assessment for Central Europe developed by Weber & Gut (2004) [Weber, E., & Gut, D. (2004). Assessing the risk of potentially invasive plant species in central Europe. Journal for Nature Conservation, 12, 171-179]. Most species received intermediate values in both tests. The species with higher scores were mainly aquatic plants and should be prohibited or kept out of trade. Chromolaena odorata (Asteraceae) obtained the highest score in both tests and therefore is the species with the highest risk to become invasive in Spain if introduced. © 2009 Elsevier GmbH. All rights reserved.

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The role of African dust in the formation of Quaternary soils on Mallorca, Spain and implications for the genesis of Red Mediterranean soils.

Muhs DR, Budahn J, Avila A, Skipp G, Freeman J, Patterson D (2010) The role of African dust in the formation of Quaternary soils on Mallorca, Spain and implications for the genesis of Red Mediterranean soils. Quaternary Science Reviews 29: 2518-2543. doi:10.1016/j.quascirev.2010.04.013.

La deposició de nitrogen en zones rurals catalanes, prop del llindar d’efectes adversos en boscos.

Àvila A (2010) La deposició de nitrogen en zones rurals catalanes, prop del llindar d’efectes adversos en boscos. UAB Divulga. 06/2010.

Aula d’Ecologia. Ciència i Tècnica 42. Cicle de conferències 2009.

Àvila A, Terradas J (eds.) (2010) Aula d’Ecologia. Ciència i Tècnica 42. Cicle de conferències 2009. Servei de Publicacions Universitat Autònoma de Barcelona. 104 pp ISBN: 978-84-490-2627-0.

La migració de les papallones: el cas de Vanessa cardui.

Àvila A, Stefanescu C (2010) La migració de les papallones: el cas de Vanessa cardui. Omnis Cellula 25:7.

L’ús de models font-receptor per determinar àrees font de components biològics (pol·len i papallones).

Alarcón M, Àvila A, Belmonte J, Stefanescu C, Izquierdo R (2010) L’ús de models font-receptor per determinar àrees font de components biològics (pol·len i papallones). Tethys 7: 3-10. doi:10.3369/tethys.2010.7.01. ISSN-1697-1523. eISSN-1139-3394.

Comparing naturalized alien plants and recipient habitats across an east-west gradient in the Mediterranean Basin

Arianoutsou M., Delipetrou P., Celesti-Grapow L., Basnou C., Bazos I., Kokkoris Y., Blasi C., Vilà M. (2010) Comparing naturalized alien plants and recipient habitats across an east-west gradient in the Mediterranean Basin. Journal of Biogeography. 37: 1811-1823.
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Doi: 10.1111/j.1365-2699.2010.02324.x

Resum:

Aim: To investigate alien plant species invasion levels in different habitats and alien species traits by comparing the naturalized flora in different areas of the same biogeographical region. Location: Spain, Italy, Greece and Cyprus. Methods: Comparison of floristic composition, species traits and recipient habitats of naturalized alien neophytes across an east-west gradient comprising four countries in the European Mediterranean basin. Results: A total of 782 naturalized neophytes were recorded; only 30 species were present in all four countries. Although floristic similarity is low, the four alien floras share the same patterns of growth form (mostly herbs), life cycle (mostly perennials) and life form (mostly therophytes, hemicryptophytes and phanerophytes). The majority of the recipient habitats were artificial. Wetlands were the natural habitats, with the highest numbers of naturalized species. Floristic similarity analyses revealed: (1) the highest floristic similarity between Italy and Spain, both of which were more similar to Greece than to Cyprus; (2) two groups of floristic similarity between habitat categories in each country (Greece-Cyprus and Italy-Spain); (3) a higher degree of homogenization in the plant assemblages in different habitats in Greece and Cyprus and a lower degree of homogenization in those in Italy and Spain; and (4) a higher degree of homogenization in artificial and natural fresh-water habitats than in the other natural habitats. Main conclusions: The floristic similarity of naturalized neophytes between the four countries is low, although the overall analysis indicates that the western group (Italy-Spain) is separated from the eastern group (Greece-Cyprus). Similar patterns emerged regarding the life-history traits and recipient habitats. The artificial habitats and the natural wet habitats are those that are invaded most and display the greatest homogenization in all four countries. Coastal habitats display a lower degree of homogenization but a high frequency of aliens. Dry shrubs and rocky habitats display a lower degree of homogenization and a low frequency of aliens. © 2010 Blackwell Publishing Ltd.

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Foraging behaviour of harvesting ants determines seed removal and dispersal

Arnan X., Retana J., Rodrigo A., Cerdá X. (2010) Foraging behaviour of harvesting ants determines seed removal and dispersal. Insectes Sociaux. 57: 421-430.
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Doi: 10.1007/s00040-010-0100-7

Resum:

Harvesting ants can affect the regeneration of plants through at least two different processes: seed removal and seed dispersal. We analyse the role of different foraging strategies of ants on patterns of seed removal and dispersal by three Messor species with considerable differences in their foraging systems. Messor capitatus workers rarely leave the nest in well-formed columns, while the other two species form foraging trails, with M. bouvieri forming temporary trails and M. barbarus foraging on a stable system of permanent foraging trails. Overall seed intake of M. capitatus colonies is considerably less than that of the two group-foraging species. There are also differences in the size of seeds collected: M. barbarus and M. capitatus harvest similar amounts of large and small seeds, while M. bouvieri harvests small seeds more intensely than large ones, due to the smaller size of the worker caste. The three Messor species differ in the percent of seed dropping of the different seed type and in the seed dispersal distance. Moreover, M. bouvieri and M. capitatus redistributed dropped seeds preferentially in bare soil and low sparse vegetation habitats, while M. barbarus redistributed seeds mainly in the high vegetation habitat. These results show that the foraging systems of these harvesting ants determine different patterns of seed removal and dispersal and, thus, affect the abundance and redistribution of seeds in the area. © 2010 International Union for the Study of Social Insects (IUSSI).

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Ant-mediated expansion of an obligate seeder species during the first years after fire

Arnan X., Rodrigo A., Molowny-Horas R., Retana J. (2010) Ant-mediated expansion of an obligate seeder species during the first years after fire. Plant Biology. 12: 842-852.
Enllaç
Doi: 10.1111/j.1438-8677.2009.00294.x

Resum:

Most obligate seeder species build up a soil seed bank that is associated with massive seed germination in the year immediately after a fire. These species are also shade-intolerant and disappear when vegetation cover closes, creating unsuitable conditions for seedling recruitment. The only way for these plants to expand their populations is when habitats suitable for seedling recruitment arise (i.e. in years immediately after a fire). However, short primary seed dispersal of obligate seeders does not allow these plants to colonise the suitable habitats, and these habitats can only be colonised by secondary seed dispersion. We hypothesised that Fumana ericoides, an obligate-seeding small shrub, not only establishes abundantly in the first year after fire, but also expands its local range in the following years due to secondary dispersal by ants while suitable habitats are still available. We tested this hypothesis using experimental studies and a simulation model of potential population expansion in a recently burned area. Results showed that F. ericoides not only established prolifically in the year immediately after fire, but was also able to recruit new individuals and expand its population in the years following the fire, despite a low germination rate and short primary seed dispersal. Ant-mediated seed dispersal and availability of suitable habitats were key factors in this phenomenon: ants redistributed seeds in suitable habitats while they were available, which accelerated the expansion of F. ericoides because new plants established far away from the core population. © 2009 German Botanical Society and The Royal Botanical Society of the Netherlands.

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Analysis of decadal time series in wet N concentrations at five rural sites in NE Spain

Avila A., Molowny-Horas R., Gimeno B.S., Peñuelas J. (2010) Analysis of decadal time series in wet N concentrations at five rural sites in NE Spain. Water, Air, and Soil Pollution. 207: 123-138.
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Doi: 10.1007/s11270-009-0124-7

Resum:

Nitrogen emissions have grown in Spain during the last 15 years. As precipitation scavenges gases and aerosols from the atmosphere, an effect on rainwater concentrations can be expected. However, time-series studies on wet N concentrations in the Iberian Peninsula are very scarce. This paper aims to fill this gap by analysing weekly rainfall N concentrations at a set of rural sites in Catalonia (NE Spain) from 1995/1996 to 2007 and a forest site monitored from 1983 to 2007. The sites encompass a range of rural environments and climate conditions, from the inland pre-Pyrenees (Sort) to the Mediterranean coast (Begur) and from north (Sort and Begur) to central (Palautordera and La Castanya) and south Catalonia (La Senia). We found a 1-year cycle for concentrations of NH 4 + and NO 3 - whereby higher values were reached at the end of spring-early summer, except at the easternmost coastal site of Begur. Weekly NH 4 + concentrations decreased with time at all sites (except at La Senia) whilst NO 3 - concentrations increased at all sites during the same period. Rainfall SO 4 2- concentrations decreased with time at all sites. The opposite trends in NO 3 - and SO 4 2- concentrations determined a shift in the relative acid contribution of those anions during the 12-13-year period. To interpret the increasing trend, mean annual NO 3 - concentrations were regressed against NO 2 Spanish emissions and to some indicators of local anthropogenic activity. The increase at Sort and Palautordera showed good correlation with local anthropogenic indicators. Wet inorganic N deposition ranged between 4.2 and 6.7 kg ha -1 year -1. When including estimates of dry deposition, total annual deposition rose up to 10-20 kg ha -1 year -1, values that have been found to initiate adverse effects on Mediterranean-type forest ecosystems. © 2009 Springer Science+Business Media B.V.

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