Long-distance windborne dispersal of the moth Cornifrons ulceratalis (Lederer, 1858) (Lepidoptera: Crambidae: Evergestinae) into the northern Mediterranean.

Dantart J, Stefanescu C, Avila A, Alarcón M (2009) Long-distance windborne dispersal of the moth Cornifrons ulceratalis (Lederer, 1858) (Lepidoptera: Crambidae: Evergestinae) into the northern Mediterranean. European Journal Entomology 106: 225-229.

Plant extinctions and introductions lead to phylogenetic and taxonomic homogenization of the European flora.

Winter M, Schweiger O, Klotz S, Nentwig W, Andriopoulos P, Arianoutsou M, Basnou C, Delipetrou P, Didziulis V, Hejda M, Hulme PE,Lambdon P, Pergl J, Pysek P, Roy DB, Kuhn I (2009) Plant extinctions and introductions lead to phylogenetic and taxonomic homogenization of the European flora. Proceedings of the National Academy of Sciences of the United States of America. doi: 10.1073/pnas.0907088106. 106 : 21721-21725 .

How well do we understand the impacts of alien species on ecosystem services? A pan-European cross-taxa assessment.

Vilà M, Basnou C, Pyšek P, Josefsson M, Genovesi P, Gollasch S, Nentwig W, Olenin S, Roques A, Roy D, Hulme P (2009) How well do we understand the impacts of alien species on ecosystem services? A pan-European cross-taxa assessment. Frontiers in Ecology and the Environment doi: 10.1890/080083.

Effect of grazing on grasslands in the Western Romanian Carpathians depends on the bedrock type.

Basnou C, Pino J, Smilauer P (2009) Effect of grazing on grasslands in the Western Romanian Carpathians depends on the bedrock type. Preslia 81: 91-104.

Growth response of mixed mediterranean oak coppices to rainfall reduction. Could selective thinning have any influence on it?

Cotillas M., Sabaté S., Gracia C., Espelta J.M. (2009) Growth response of mixed mediterranean oak coppices to rainfall reduction. Could selective thinning have any influence on it?. Forest Ecology and Management. 258: 1677-1683.
Enllaç
Doi: 10.1016/j.foreco.2009.07.033

Resum:

Climate change is one of the major challenges for ecosystem conservation. One of the most vulnerable areas to climate change is the Mediterranean Basin which is expected to suffer important changes in temperature and precipitation in the next few decades, leading to a warmer and dryer climate. Therefore, it is necessary to determine species-specific responses to increased drought to predict possible future changes in the structure and composition of Mediterranean forests, as well as to identify appropriate management strategies to mitigate these effects. The main aim of this study has been to experimentally simulate the effects of a 15% reduction in annual rainfall on the survival and growth of two co-occurring Mediterranean oaks with contrasting leaf-habit (the evergreen Quercus ilex spp. ilex and the winter-deciduous Quercus cerrioides) and, to assess whether traditional selective thinning carried out in these mixed oak coppices (i.e. selection of one to few stems per stump) can modify the consequences of rainfall reduction. Soil moisture decreased under the rainfall reduction level while it increased in the thinned plots. Reduced rainfall did not influence tree mortality, but did lead to species-specific effects on height growth: no changes were observed in Q. ilex while height growth rate of Q. cerrioides decreased (c.a. 20%). Selective thinning improved tree growth (c.a. 50%) in stands both under natural and, and to a lesser extent, under reduced rainfall conditions. Nevertheless, the positive effects of thinning rapidly declined during our three years experiment, probably because the vigorous resprouting of thinned stumps. Our results show that the forecasted reduction in annual rainfall for the Western Mediterranean Basin can constrain the growth of some deciduous oaks in mixed oak coppices. Traditional selective thinning can increase soil moisture and encourage tree growth, thus partially mitigating this effect. However, the transient results observed in this experiment suggest the need to reconsider the intensity and the frequency of this traditional management practice in light of new climatic scenarios. © 2009 Elsevier B.V. All rights reserved.

Llegeix més

Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability

Craine J.M., Elmore A.J., Aidar M.P.M., Bustamante M., Dawson T.E., Hobbie E.A., Kahmen A., MacK M.C., McLauchlan K.K., Michelsen A., Nardoto G.B., Pardo L.H., Peñuelas J., Reich P.B., Schuur E.A.G., Stock W.D., Templer P.H., Virginia R.A., Welker J.M., Wright I.J. (2009) Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability. New Phytologist. 183: 980-992.
Enllaç
Doi: 10.1111/j.1469-8137.2009.02917.x

Resum:

Ratios of nitrogen (N) isotopes in leaves could elucidate underlying patterns of N cycling across ecological gradients. To better understand global-scale patterns of N cycling, we compiled data on foliar N isotope ratios (δ15N), foliar N concentrations, mycorrhizal type and climate for over 11 000 plants worldwide. Arbuscular mycorrhizal, ectomycorrhizal, and ericoid mycorrhizal plants were depleted in foliar δ15N by 2‰, 3.2‰, 5.9‰, respectively, relative to nonmycorrhizal plants. Foliar δ15N increased with decreasing mean annual precipitation and with increasing mean annual temperature (MAT) across sites with MAT ≥ -0.5°C, but was invariant with MAT across sites with MAT < -0.5°C. In independent landscape-level to regional-level studies, foliar δ15N increased with increasing N availability; at the global scale, foliar δ15N increased with increasing foliar N concentrations and decreasing foliar phosphorus (P) concentrations. Together, these results suggest that warm, dry ecosystems have the highest N availability, while plants with high N concentrations, on average, occupy sites with higher N availability than plants with low N concentrations. Global-scale comparisons of other components of the N cycle are still required for better mechanistic understanding of the determinants of variation in foliar δ15N and ultimately global patterns in N cycling.

Llegeix més

Plant-hummingbird interactions in the West Indies: Floral specialisation gradients associated with environment and hummingbird size

Dalsgaard B., Martín González A.M., Olesen J.M., Ollerton J., Timmermann A., Andersen L.H., Tossas A.G. (2009) Plant-hummingbird interactions in the West Indies: Floral specialisation gradients associated with environment and hummingbird size. Oecologia. 159: 757-766.
Enllaç
Doi: 10.1007/s00442-008-1255-z

Resum:

Floral phenotype and pollination system of a plant may be influenced by the abiotic environment and the local pollinator assemblage. This was investigated in seven plant-hummingbird assemblages on the West Indian islands of Grenada, Dominica and Puerto Rico. We report all hummingbird and insect pollinators of 49 hummingbird-pollinated plant species, as well as six quantitative and semi-quantitative floral characters that determine visitor restriction, attraction and reward. Using nonmetric multidimensional scaling analysis, we show that hummingbird-pollinated plants in the West Indies separate in floral phenotypic space into two gradients-one associated with the abiotic environment and another with hummingbird size. Plants pollinated by large, long-billed hummingbirds had flowers with long corolla tube, large amounts of nectar and showy orange-red colouration. These attracted few or no insect species, whereas plants pollinated by small, short-billed hummingbirds were frequently pollinated by insects, particularly lepidopterans. The separation of plants related to environmental factors showed that species in the wet and cold highlands produced large amounts of dilute nectar, possessed no or a weak odour, and were associated with few insects, particularly few hymenopterans, compared to plants in the dry and warm lowlands. The most specialised hummingbird-pollinated plants are found in the West Indian highlands where they are pollinated by mainly large, long-billed hummingbirds. At the other extreme, highly generalised plants growing in the dry and warm lowlands are pollinated by small, short-billed hummingbirds and numerous insect species. This illustrates that, even within the hummingbird-pollinated flora, pollination syndrome and the degree of specialisation may vary tremendously depending on pollinator morphology and environment. © 2008 Springer-Verlag.

Llegeix més

Espècies invasores: el problema de sobreviure en nous ambients.

Sol D (2009) Espècies invasores: el problema de sobreviure en nous ambients. Atzavara 18: 31-38.

The cognitive-buffer hypothesis for the evolution of large brains in R. Dukas, and R. M. Ratcliffe, eds.

Sol D (2009) The cognitive-buffer hypothesis for the evolution of large brains in R. Dukas, and R. M. Ratcliffe, eds. Cognitive ecology. Chicago University Press.

Ecosystem services in dynamic and contested landscapes: the case of UK uplands. In: Winter, Michael and Matt Lobley (eds).

Klaus H, Beharry N, Bonn A, Burt T, Holden J, Ravera F, Reed M, Stringer L, Tarrasón D (2009) Ecosystem services in dynamic and contested landscapes: the case of UK uplands. In: Winter, Michael and Matt Lobley (eds). Land Use and Management: The New Debate Earthscan.

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