Transition from juvenility to maturity strengthens photosynthesis in sclerophyllous and deciduous but not in semi-deciduous Mediterranean shrubs

2021 ◽  
Vol 181 ◽  
pp. 104265
Author(s):  
Christos Chondrogiannis ◽  
George Grammatikopoulos
Keyword(s):  
2021 ◽  
Author(s):  
Rafael Pimentel ◽  
Pedro Torralbo ◽  
Javier Aparicio ◽  
María José Pérez-Palazón ◽  
Ana Andreu ◽  
...  

<p>Mediterranean mountain areas are especially vulnerable to changes. Climatic trends observed in the last decades point out to an increasing number of extreme events (i.e., number of heat waves and droughts) and consequently, a direct alteration of the hydrological states of their associated ecosystems. The savanna type ecosystem called <em>dehesa</em> is one of them. This system is the result of a long-term co-evolution of indigenous ecosystems and human settlement in a sustainable balance, with high relevance from both the environmental (biodiversity) and socioeconomic (livestock farming, including Iberian pork food industry) point of view. <em>Dehesa </em>systems have a complex vegetation cover structure, where isolated trees, mainly holm oak, cork oak and oak, Mediterranean shrubs, and pastures coexist. Different problems have arisen in <em>dehesa</em> during last years, an example of them are seca episodes, a disease of oak trees that results in drying and final death. This condition is caused by a fungus, but very likely triggered by external hydrological related conditions like air temperature and soil water content.  Remote sensing techniques have been widely used as the best alternative to monitor vegetation patterns over these areas. However, the presence of clouds and the fixed spatiotemporal resolution of these sensors constitute a limitation in more local studies.</p><p>This work proposes the combined use of remote sensing by both terrestrial photography and satelital sensors, and hydrometeorological information as data sources for improving the hydrological characterization of vegetation in <em>dehesa</em> areas. The study was carried out in the Santa Clotilde experimental area, within the Cardeña-Montoro Natural Park (southern Spain). Three years of local sub-daily terrestrial photography and hydrometeorological information allowed us to define different hydrometeorological/ecohydrological indicators that are representative of key vegetation states. This local information is linked with vegetation indexes derived from high spatial resolution satellite information (i.e., Landsat TM, ETM+ and OLI (30 m x 30 m) and Sentinel-2 (10 m x 10 m) and distributed meteorological variables to extend the results from the local to the watershed scale. The promising results will be used in a short future as the basis of an advanced monitoring service where meteorological seasonal forecast information could be used to derive key indicators and help in a priori diagnosis of the system facilitating decisions making.</p><p>This work has been funded by project SIERRA Seguimiento hIdrológico de la vEgetación en montaña mediteRránea mediante fusión de sensores Remotos en Andalucía), with the economic collaboration of the European Funding for Rural Development (FEDER) and the Office for Economy, Knowledge, Enterprises and University of the Andalusian Regional Government.</p>


Trees ◽  
2018 ◽  
Vol 33 (2) ◽  
pp. 507-519 ◽  
Author(s):  
Rodrigo Méndez-Alonzo ◽  
Frank W. Ewers ◽  
Anna L. Jacobsen ◽  
R. Brandon Pratt ◽  
Christine Scoffoni ◽  
...  

Author(s):  
A. Aïssa ◽  
F. Manolaraki ◽  
H. Ben Salem ◽  
H. Hoste ◽  
K. Kraiem

Background: Mediterranean shrub species cover more than 70% of the total area in Tunisia and in summer when the herbaceous species have wilted, they constitute feeding resource for livestock. The use of tanniniferous shrubs seems to be a good alternative to control gastrointestinal nematodes infections in small ruminants. This study evaluated the in vitro anthelmintic (AH) effect of Ceratonia siliqua (C. siliqua), Periploca angustifolia Labill. (P. angustifolia) and Medicago arborea (M. arborea) against Haemonchus contortus third stage larvae (L3). Methods: The larval exsheathment assay (LEA) was used to determine the proportions (%) of exsheathment of five acetonic extracts at different concentrations (1200, 600, 300, 150 μg/ml). To confirm the role of tannins in the AH effects of extracts, polyvinyl polypyrolidone (PVPP) was used as deactivating chemical tannins. Result: The highest % L3 exsheathed was recorded for M. arborea (55.01%) and the lowest value was founded for C. siliqua and P. angustifolia leaves (16.26%). Our results were concentration-dependent (P less than 0.001). The % of exsheathment increased as the time of incubation increased (P less than 0.001). P. angustifolia pods recorded the lowest EC50 value (P less than 0.05). After PVPP addition, all the acetonic extracts showed a restoration of L3 exsheathment values similar to control values (P less than 0.001).


2009 ◽  
Vol 11 (7) ◽  
pp. 1375 ◽  
Author(s):  
Eduardo Moreno-Jiménez ◽  
Jesús M. Peñalosa ◽  
Elvira Esteban ◽  
M. Pilar Bernal
Keyword(s):  

2010 ◽  
Vol 48 (3) ◽  
pp. 348-354 ◽  
Author(s):  
S. Redondo-Gomez ◽  
J. M. Mancilla-Leyton ◽  
E. Mateos-Naranjo ◽  
J. Cambrolle ◽  
A. Martin-Vicente

Ecohydrology ◽  
2013 ◽  
Vol 7 (2) ◽  
pp. 783-793 ◽  
Author(s):  
M. Paz Esquivias ◽  
María Zunzunegui ◽  
Mari Cruz Díaz Barradas ◽  
Leonor Álvarez-Cansino

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