<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Andivia, Enrique</style></author><author><style face="normal" font="default" size="100%">FERNÁNDEZ, MANUEL</style></author><author><style face="normal" font="default" size="100%">VÁZQUEZ-PIQUÉ, JAVIER</style></author><author><style face="normal" font="default" size="100%">González-Pérez, Aranzazu</style></author><author><style face="normal" font="default" size="100%">TAPIAS, RAÚL</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Nutrients return from leaves and litterfall in a mediterranean cork oak (Quercus suber L.) forest in southwestern Spain</style></title><secondary-title><style face="normal" font="default" size="100%">European Journal of Forest Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">litterfall</style></keyword><keyword><style  face="normal" font="default" size="100%">Nutrients cycling</style></keyword><keyword><style  face="normal" font="default" size="100%">Nutrients return</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s10342-009-0308-0</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">129</style></volume><pages><style face="normal" font="default" size="100%">5 - 12</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The knowledge of the cycle of nutrients is fundamental for the correct comprehension of the tree–soil relationship and for an adequate forest management. In order to analyse the nutrients return from leaves and litterfall in a Mediterranean cork oak forest in southwestern Spain, 12 trees were randomly selected and litterfall collected for 2 years. Samples were taken monthly and separated in different fractions (leaves, twigs, catkins, acorns and mis- cellaneous), then leaves nutrients were analyzed. Simulta- neously, we analyzed the nutrient content of living leaves from the same trees in each season during 1 year. The ana- lyzed nutrients were C, N, P, K, Ca, Mg, Fe, Mn, S, Cu, Zn and Mo. Annual patterns of each nutrient in fallen leaves were characterized and compared with seasonal values of these nutrients in living leaves. Leaves fall has two annual maximum, first and most important in spring around April coinciding with renewal of foliar cover and second around October. Main concentration patterns of N, P and K are related with phenological patterns, in consequence mini- mumconcentration in leaves fall were obtained in periods of growing and maximum litterfall. Concentrations of Ca, Fe and Mn increase with the age of the leaves and maximum concentrations were obtained before periods of maximum litterfall while concentrations of Cu, Mo and Mg stay stable. Communicated by A. Merino. A. Gonza This article belongs to the special issue ‘‘Plant–soil relationships in Southern European forests’’. E. Andivia (&amp;)  M. Ferna ´lez-Pe Department of Forest Sciences, University of Huelva, Ctra. Palos–La Ra ´rez  R. Tapias Huelva, Spain e-mail: enrique.andivia@dcaf.uhu.es ´ndez  J. Va ´zquez-Pique ´  ´bida, s/n. 21819 Palos de la Frontera, Seasonal analysis of nutrients in living leaves collected from the same trees in four different periods of the year allowed to corroborate the patterns of leaves fall and the probable osmotic function of K.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">cork oak wood a hard material to sample and to measure</style></title><secondary-title><style face="normal" font="default" size="100%">Suberwood2005: New challenges for integration of cork oak forests and products, Scientific and Technical Conference, Huelva, Spain, 20, 21 and 22 October 2005.</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">Universidad de Huelva</style></publisher><pub-location><style face="normal" font="default" size="100%">Huelva</style></pub-location><pages><style face="normal" font="default" size="100%">456</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Different studies within the Suberwood project required measurements of wood growth in cork oak trees (Quercus suber L.), including tree ring analysis, as a basis to analyse the influence on tree growth of stress effects, namely those deriving from climatic conditions (i.e. water deficit) or from the cork extraction. The research partners have experienced serious difficulties in these tasks and some examples are presented and discussed. The first difficulty regards sampling because cork oak harvesting is forbidden in Portugal and advantage has to be taken from legally authorised tree fellings. The available material therefore consists mainly in thinning material (young trees), dead or diseased trees, and trees with damaged stems due to improper cork harvesting, which are useless for such studies. In most cases the information concerning the stand management is lacking, namely regarding the time of cork extraction and of other silvicultural operations (i.e. pruning). Therefore the experimental design regarding treatments and repetitions often cannot follow the conventional statistical guidelines. The cork oak wood also has anatomical and structural features that bring considerable complexity for ring definition. The wood has a semi-ring porosity with poor growth ring definition and it is very difficult, and frequently impossible, to accurately identify growth rings and to link measurements to a certain year. Additionally cork extraction disturbs wood growth and anatomy. Different observation approaches were tested: overall microscopical observations, continuous radial measurement of vessel dimensions and density, continuous radial microdensitometric profiles, cambial wounding. The use of non-destructive samples (i.e. cores or small wood samples) adds to the uncertainty encountered. Stem discs offer a better observation but differences among different radii are often very large.</style></abstract></record></records></xml>