5 Resprouting Dynamics
Josep Maria Espelta, Santiago Sabate and Javier Retana
5.1 Introduction
Resprouting, i.e. the production of sprouts from buds on pre-existing plant
organs, is one of the most important mechanisms of plant regeneration under natural and anthropogenic disturbances. This response has been widely
observed in many plant communities around the world, but it is probably in
Mediterranean regions that it has received most attention (Keeley and Zedler
1978). In fact, the resprouting ability of many Mediterranean shrubs and
trees has been one of the most important keystones to building up the paradigm of the resilience (sensu Westman 1986) and autosuccessional nature
(Hanes 1971) of these communities after disturbances. However, the evolutionary meaning and the selection forces that lead to the resprouting habit
have been the focus of a long controversy. Since fire is one of the most typical
disturbances in Mediterranean areas, and resprouting is a common response
to fire, early studies pointed out that it was an adaptation, a trait selected by
fire (Naveh 1974). Recent reviews have criticized this concept arguing that:
(1) resprouting is an old and widespread trait among many angiosperm species, present in taxa not regularly exposed to fire (Axelrod 1989); and (2)
other selective factors, such as grazing or drought, may also lead to a resprouting habit (James 1984; Keeley 1986). Thus, resprouting should be considered as an attribute evolved in response to multiple possible selective
forces, a sort of reiteration by which a plant reverts to a juvenile state after
damage. In the case of Mediterranean species, the resprouting habit is usually
accompanied by other characteristic life history traits, such as longevity, slow
growth and some degree of shade tolerance during juvenile stages (Keeley
1986).
Most present-day holm oak stands in the western Mediterranean Basin
have originated through resprouting after disturbances such as fire, overgrazing, firewood extraction or charcoal production. This phenomenon has
produced a certain homogeneity on the structure of these forests, usually
characterized by high-density stands of relatively small stump sprouts
Ecological Studies, Vol. 137
Ferran RoclA et aI. (eds) Ecology of Mediterranean
Evergreen Oak Forests
© Springer-Verlag, Berlin Heidelberg 1999
Josep Maria Espelta, Santiago Sabate and Javier Retana
5.1 Introduction
Resprouting, i.e. the production of sprouts from buds on pre-existing plant
organs, is one of the most important mechanisms of plant regeneration under natural and anthropogenic disturbances. This response has been widely
observed in many plant communities around the world, but it is probably in
Mediterranean regions that it has received most attention (Keeley and Zedler
1978). In fact, the resprouting ability of many Mediterranean shrubs and
trees has been one of the most important keystones to building up the paradigm of the resilience (sensu Westman 1986) and autosuccessional nature
(Hanes 1971) of these communities after disturbances. However, the evolutionary meaning and the selection forces that lead to the resprouting habit
have been the focus of a long controversy. Since fire is one of the most typical
disturbances in Mediterranean areas, and resprouting is a common response
to fire, early studies pointed out that it was an adaptation, a trait selected by
fire (Naveh 1974). Recent reviews have criticized this concept arguing that:
(1) resprouting is an old and widespread trait among many angiosperm species, present in taxa not regularly exposed to fire (Axelrod 1989); and (2)
other selective factors, such as grazing or drought, may also lead to a resprouting habit (James 1984; Keeley 1986). Thus, resprouting should be considered as an attribute evolved in response to multiple possible selective
forces, a sort of reiteration by which a plant reverts to a juvenile state after
damage. In the case of Mediterranean species, the resprouting habit is usually
accompanied by other characteristic life history traits, such as longevity, slow
growth and some degree of shade tolerance during juvenile stages (Keeley
1986).
Most present-day holm oak stands in the western Mediterranean Basin
have originated through resprouting after disturbances such as fire, overgrazing, firewood extraction or charcoal production. This phenomenon has
produced a certain homogeneity on the structure of these forests, usually
characterized by high-density stands of relatively small stump sprouts
Ecological Studies, Vol. 137
Ferran RoclA et aI. (eds) Ecology of Mediterranean
Evergreen Oak Forests
© Springer-Verlag, Berlin Heidelberg 1999