Assessing the resilience of Mediterranean holm oaks to disturbances using selective thinning

López B.C., Gracia C.A., Sabaté S., Keenan T. (2009) Assessing the resilience of Mediterranean holm oaks to disturbances using selective thinning. Acta Oecologica. 35: 849-854.
Enllaç
Doi: 10.1016/j.actao.2009.09.001

Resum:

Climate change will increase the frequency and the intensity of droughts in the Mediterranean region, likely reducing growth and increasing mortality of holm oaks (Quercus ilex), one of the most abundant species of Mediterranean forests. In water-limited systems such as those of the Mediterranean, carbon allocation patterns strongly favour belowground accumulation, especially in large subterranean structures called lignotubers. The resilience of these forests depends largely on the replenishment rate of these carbon reserves after disturbances. An experimental thinning, with two intensities (removal of 40% and 80% of basal area), was performed in 1992 in a holm oak forest at the Prades Experimental Complex of Catchments (NE Spain). In 2002, a second thinning was carried out in subplots within the former experimental 0.5 ha plots. Samples from the lignotubers of holm oak trees were analyzed for starch, and both mobile and immobile chemical components, in order to assess the resilience of holm oaks to repeated disturbances. Our results show that after 10 years, starch stocks in the lignotubers have only recovered to half their former values. Removing 40% of the basal area instead of 80% is suggested to be the better managing option for this kind of forests. © 2009 Elsevier Masson SAS. All rights reserved.

Llegeix més

Process based inventory of isoprenoid emissions from European forests: model comparisons, current knowledge and uncertainties.

Keenan T, Niinemets Ü, Sabaté S, Gracia C, Peñuelas J (2009) Process based inventory of isoprenoid emissions from European forests: model comparisons, current knowledge and uncertainties. Atmospheric Chemistry and Physics Discussions 9: 6147-6206.

Impactos del cambio climático sobre los bosques mediterráneos analizados en el marco de distintos proyectos de investigación. V Congreso Forestal Español. Montes y Sociedad: Saber que hacer.

Sabaté S, Espelta JM,Gracia C, Claramunt B, Cotillas de la Torre M, Keenan T, Sánchez Humanes B, Vayreda J, Plà E (2009) Impactos del cambio climático sobre los bosques mediterráneos analizados en el marco de distintos proyectos de investigación. V Congreso Forestal Español. Montes y Sociedad: Saber que hacer. S.E.C.F-Junta de Castilla y León. ISBN: 978-84-936854-6-1.

European BVOC emissions: A model comparison, and future emission trends from European forests. BG0064

Keenan T, Niinemets U, Gracia C, Noe S, Peñuelas J, Sabaté S (2008) European BVOC emissions: A model comparison, and future emission trends from European forests. BG0064 EGU2008-A-04247 BG4.1-1FR3P-0064.

Impacts on biodiversity of Mediterranean ecosystems. In Settele, J. et al. (eds.) (in prep.): Atlas of Biodiversity Risks - from Europe to the globe, from stories to maps.

Peñuelas J, Estiarte M, Prieto P, Sardans J, Moreno JM, Torres I, Céspedes B, Pla E, Sabaté S, Gracia C (2008) Impacts on biodiversity of Mediterranean ecosystems. In Settele, J. et al. (eds.) (in prep.): Atlas of Biodiversity Risks - from Europe to the globe, from stories to maps. Pensoft, Sofia & Moscow (www.pensoftonline.net/alarm-atlas-info) pp.76-77.

Estimating annual rainfall threshold for establishment of tree species in water-limited ecosystems using tree-ring data

López B.C., Holmgren M., Sabaté S., Gracia C.A. (2008) Estimating annual rainfall threshold for establishment of tree species in water-limited ecosystems using tree-ring data. Journal of Arid Environments. 72: 602-611.
Enllaç
Doi: 10.1016/j.jaridenv.2007.10.012

Resum:

In arid and semi-arid ecosystems, water availability is discontinuous, highly variable, and characterized by discrete pulse events separated by long periods of limited resource availability. Plant recruitment in these ecosystems is also episodic and dependent on the water available during and after these discrete rainfall events. Precipitation thresholds for plant establishment have been estimated mainly for herbaceous plants and tree seedlings, but extrapolation of short-term results based on seedlings to natural tree populations is difficult. Nevertheless, estimations of water availability thresholds for tree recruitment are essential for successful policies on forest conservation and restoration. We propose a methodology to estimate precipitation thresholds for adult tree populations using tree-ring series and precipitation data. We used this methodology with two Prosopis species from South America: Prosopis pallida and Prosopis chilensis. Results indicate a precipitation threshold of around 85 mm for the establishment of P. pallida trees, whereas the threshold for P. chilensis is likely to be much higher. © 2007 Elsevier Ltd. All rights reserved.

Llegeix més

Forest Ecophysiological Models and Carbon Sequestration in: Managing Forest Ecosystems - The Challenge of Climate Change. (Eds. Bravo et al.).

Keenan T, Sabaté S, Gracia C (2008) Forest Ecophysiological Models and Carbon Sequestration in: Managing Forest Ecosystems - The Challenge of Climate Change. (Eds. Bravo et al.). Springer ISBN:978-1-4020-8342-6.

A human and scientific perspective of Ramón Margalef (1919-2004). En: Unity in Diversity: Reflections on Ecology after de legacy of Ramón Margalef.

Gracia C (2007) A human and scientific perspective of Ramón Margalef (1919-2004). En: Unity in Diversity: Reflections on Ecology after de legacy of Ramón Margalef. Fundación BBVA

Carbon pools in Mediterranean forests: comparing eddy covariance and GOTILWA+ model results.

Gracia C (2007) Carbon pools in Mediterranean forests: comparing eddy covariance and GOTILWA+ model results. Slovenian Forestry Institute (SFI), Ljubljana, Slovenia.Slovenian Research Agency

Unity in Diversity: Reflections on Ecology after de legacy of Ramón Margalef. (C.Gracia et al. Editores).

Gracia C (2007) Unity in Diversity: Reflections on Ecology after de legacy of Ramón Margalef. (C.Gracia et al. Editores). Fundación BBVA.

Pàgines