One of the most universal characten's tics of perennia/ plants is the recurrent abscission of their organs. This phenomenon is a previous and indispensable step for the recycling of plant nutrients, and has thus became one of the most classical tapies in forest eco/ogy. Important aspects of this phenomenon are the amount of lifter fol/ and ifs seasonal distribution. The /evels of annual production are extremely variable, depending on the soif and climate of the different biotopes. However, the phenology of the shedding of the different lifter parts shows a great cons ta ney in individual species and reflects the strategies selected for each species very weil. The different pheno/ogical patterns
of abscission were summarized by Addicott and lyon fl 973J. However, Mediterranean woody species have not received much attention and hence many of the pheno/ogical patterns observed among these species are not adequate/y reflected in the usual classifications. Furthermore, the Mediterranean region shows a great diversity of phenological patterns, which make if special/y interesting. ln the present work, a description is offered of the pheno/ogical characteristics of some of the woody species most representative of the semiarid and subhumid bioclimates of the central plateau of the lberian Peninsula. The information obtained has al/owed us to e/ucidate certain causes of the seasonality of abscission and the reasons for the selection of one or another of the strategies observed in each of the study areas.