Predicting the future of forests in the Mediterranean under climate change, with niche- and process-based models: CO2 matters!.

Keenan T, Serra J, Lloret F, Ninyerola M, Sabaté S (2010) Predicting the future of forests in the Mediterranean under climate change, with niche- and process-based models: CO2 matters!. Global Change Biology 17: 565-579. doi:10.1111/j.13652486.2010.02254.x.

Drought-Induced Multifactor Decline of Scots Pine in the Pyrenees and Potential Vegetation Change by the Expansion of Co-occurring Oak Species

Galiano L., Martínez-Vilalta J., Lloret F. (2010) Drought-Induced Multifactor Decline of Scots Pine in the Pyrenees and Potential Vegetation Change by the Expansion of Co-occurring Oak Species. Ecosystems. 13: 978-991.
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Doi: 10.1007/s10021-010-9368-8

Resum:

Episodes of drought-induced tree dieback have been recently observed in many forest areas of the world, particularly at the dry edge of species distributions. Under climate change, those effects could signal potential vegetation shifts occurring over large geographical areas, with major impacts on ecosystem form and function. In this article, we studied the effect of a single drought episode, occurred which in summer 2005, on a Scots pine population in central Pyrenees (NE Spain). Our main objective was to study the environmental correlates of forest decline and vegetation change at the plot level. General and generalized linear models were used to study the relationship between canopy defoliation, mortality and recruitment, and plot characteristics. A drought-driven multifactor dieback was observed in the study forest. Defoliation and mortality were associated with the local level of drought stress estimated at each plot. In addition, stand structure, soil properties, and mistletoe infection were also associated with the observed pattern of defoliation, presumably acting as long-term predisposing factors. Recruitment of Scots pine was low in all plots. In contrast, we observed abundant recruitment of other tree species, mostly Quercus ilex and Q. humilis, particularly in plots where Scots pine showed high defoliation and mortality. These results suggest that an altitudinal upwards migration of Quercus species, mediated by the dieback of the currently dominant species, may take place in the studied slopes. Many rear-edge populations of Scots pine sheltered in the mountain environments of the Iberian Peninsula could be at risk under future climate scenarios. © 2010 Springer Science+Business Media, LLC.

Llegeix més

Patterns and controls of the variability of radiation use efficiency and primary productivity across terrestrial ecosystems

Garbulsky M.F., Peñuelas J., Papale D., Ardö J., Goulden M.L., Kiely G., Richardson A.D., Rotenberg E., Veenendaal E.M., Filella I. (2010) Patterns and controls of the variability of radiation use efficiency and primary productivity across terrestrial ecosystems. Global Ecology and Biogeography. 19: 253-267.
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Doi: 10.1111/j.1466-8238.2009.00504.x

Resum:

Aim: The controls of gross radiation use efficiency (RUE), the ratio between gross primary productivity (GPP) and the radiation intercepted by terrestrial vegetation, and its spatial and temporal variation are not yet fully understood. Our objectives were to analyse and synthesize the spatial variability of GPP and the spatial and temporal variability of RUE and its climatic controls for a wide range of vegetation types. Location: A global range of sites from tundra to rain forest. Methods: We analysed a global dataset on photosynthetic uptake and climatic variables from 35 eddy covariance (EC) flux sites spanning between 100 and 2200 mm mean annual rainfall and between -13 and 26°C mean annual temperature. RUE was calculated from the data provided by EC flux sites and remote sensing (MODIS). Results: Rainfall and actual evapotranspiration (AET) positively influenced the spatial variation of annual GPP, whereas temperature only influenced the GPP of forests. Annual and maximum RUE were also positively controlled primarily by annual rainfall. The main control parameters of the growth season variation of gross RUE varied for each ecosystem type. Overall, the ratio between actual and potential evapotranspiration and a surrogate for the energy balance explained a greater proportion of the seasonal variation of RUE than the vapour pressure deficit (VPD), AET and precipitation. Temperature was important for determining the intra-annual variability of the RUE at the coldest energy-limited sites. Main conclusions: Our analysis supports the idea that the annual functioning of vegetation that is adapted to its local environment is more constrained by water availability than by temperature. The spatial variability of annual and maximum RUE can be largely explained by annual precipitation, more than by vegetation type. The intra-annual variation of RUE was mainly linked to the energy balance and water availability along the climatic gradient. Furthermore, we showed that intra-annual variation of gross RUE is only weakly influenced by VPD and temperature, contrary to what is frequently assumed. Our results provide a better understanding of the spatial and temporal controls of the RUE and thus could lead to a better estimation of ecosystem carbon fixation and better modelling. © 2009 Blackwell Publishing Ltd.

Llegeix més

Predicting plant invaders in the Mediterranean through a weed risk assessment system

Gassó N., Basnou C., Vilà M. (2010) Predicting plant invaders in the Mediterranean through a weed risk assessment system. Biological Invasions. 12: 463-476.
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Doi: 10.1007/s10530-009-9451-2

Resum:

Risk assessment schemes have been developed to identify potential invasive species, prevent their spread and reduce their damaging effects. One of the most promising tools for detecting plant invaders is the weed risk assessment (WRA) scheme developed for Australia. Our study explores whether the Australian WRA can satisfactorily predict the invasion status of alien plants in the Mediterranean Basin by screening 100 invasive and 97 casual species in Spain. Furthermore, we analysed whether the factors taken into account in the WRA are linked to invasion likelihood (i.e., invasion status) or to impacts. The outcome was that 94% of the invasive species were rejected, 50% of the casual species were rejected and 29% of them required further evaluation. The accuracy for casuals is lower than in other studies that have tested non-invasive (i.e., casuals or non-escaped) alien species. We postulate that low accuracy for casual species could result from: (1) an incorrect "a priori" expert classification of the species status, (2) a high weight of the WRA scores given to potential impacts, and (3) casual species being prone to becoming invasive when reaching a minimum residence time threshold. Therefore, the WRA could be working as a precaution early-warning system to identify casual species with potential to become invasive. © 2009 Springer Science+Business Media B.V.

Llegeix més

Spreading to a limit: The time required for a neophyte to reach its maximum range

Gassó N., Pyšek P., Vilà M., Williamson M. (2010) Spreading to a limit: The time required for a neophyte to reach its maximum range. Diversity and Distributions. 16: 310-311.
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Doi: 10.1111/j.1472-4642.2010.00647.x

Resum:

The average range size of alien plants in Spain reaches a maximum at 143 years. This is consistent with estimates of such a maximum in Ireland, Britain, Germany and the Czech Republic. A round figure of about 150 years on average for neophytes to reach their maximum range in European countries is indicated. © 2010 Blackwell Publishing Ltd.

Llegeix més

Land cover change in Europe between 1950 and 2000 determined employing aerial photography

Gerard F., Petit S., Smith G., Thomson A., Brown N., Manchester S., Wadsworth R., Bugar G., Halada L., Bezák P., Boltiziar M., de Badts E., Halabuk A., Mojses M., Petrovic F., Gregor M., Hazeu G., Mücher C.A., Wachowicz M., Huitu H., Tuominen S., Köhler R., Olschofsky K., Ziese H., Kolar J., Sustera J., Luque S., Pino J., Pons X., Roda F., Roscher M., Feranec J. (2010) Land cover change in Europe between 1950 and 2000 determined employing aerial photography. Progress in Physical Geography. 34: 183-205.
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Doi: 10.1177/0309133309360141

Resum:

BIOPRESS ('Linking Pan-European Land Cover Change to Pressures on Biodiversity'), a European Commission funded 'Global Monitoring for Environment and Security' project, produced land cover change information (1950-2000) for Europe from aerial photographs and tested the suitability of this for monitoring habitats and biodiversity. The methods and results related to the land cover change work are summarized. Changes in land cover were established through 73 window and 59 transect samples distributed across Europe. Although the sample size was too small and biased to fully represent the spatial variability observed in Europe, the work highlighted the importance of method consistency, the choice of nomenclature and spatial scale. The results suggest different processes are taking place in different parts of Europe: the Boreal and Alpine regions are dominated by forest management; abandonment and intensification are mainly encountered in the Mediterranean; urbanization and drainage are more characteristic of the Continental and Atlantic regions. © The Author(s) 2010.

Llegeix més

Automatic matching of Landsat image series to high resolution orhorectified imagery

Pons X, Moré G, Pesquer L (2010) Automatic matching of Landsat image series to high resolution orhorectified imagery. Proceedings of the ESA Living Planet Symposium. CD-ROM  edition. ESA reference document: SP-686, Bergen (Norway).

Estimación y cartografía de parámetros ecológicos en tres especies forestales (Quercus ilex L. subsp ilex, Fagus sylvatica L. y Pinus halepensis L.) con datos LiDAR.

Zaldo V, Moré G, Pons X (2010) Estimación y cartografía de parámetros ecológicos en tres especies forestales (Quercus ilex L. subsp ilex, Fagus sylvatica L. y Pinus halepensis L.) con datos LiDAR. Revista de Teledetección 34: 55-68.

Aplicacions del LiDAR als inventaris forestals.

Zaldo V, Moré G, Pons X (2010) Aplicacions del LiDAR als inventaris forestals. Silvicultura 62 pp:7-10.

Soil water retention under dryin.g process in a soil amended with composted and thermally dried sewage sludges (Poster 0202), pp. 79-82 Published in DVD. Symposium 2.1.2, The physics of soil pore structure dynamics. 19th World Congress of Soil Science.

Ojeda G, Alcañiz JM (2010) Soil water retention under dryin.g process in a soil amended with composted and thermally dried sewage sludges (Poster 0202), pp. 79-82 Published in DVD. Symposium 2.1.2, The physics of soil pore structure dynamics. 19th World Congress of Soil Science. Soil Solutions for a Changing World, Brisbane, Australia 1 – 6 August 2010 (http://www.iuss.org/19th%20WCSS/.%5Csymposium/pdf/2208.pdf).

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