Cyclic patch dynamics in a Macaronesian island forest.
Clima, Ambiente e Paisagem
Elias R. B. & Dias E. 2009. Cyclic patch dynamics in a Macaronesian island forest. Community Ecology 10(1): 25-34.
We assess if the structural and floristic diversity of Juniperus-Ilex forests from Pico Island (Azores) corresponds to a mosaic of different phases of a forest cycle, by identifying the phases of that cycle and the dynamic relations between them. Eight 100 m 2 plots were placed randomly in areas with structural and floristic differences but having in common the presence of live and/or dead individuals of the dominant tree species ( Juniperus brevifolia ). In each plot the number of seedlings, saplings, and adults as well as canopy height and width and maximum height of live Juniperus brevifolia and Ilex azorica adults were recorded. The floristic composition was determined in a 25 m 2 plot, placed inside each 100 m 2 plot. Juniperus-Ilex forests show a cyclic patch dynamic triggered by the senescence and death of even-aged individuals of J. brevifolia . In this forest cycle, five phases were identified, such as gap, building, mature, initial degenerative and final degenerative. The first two phases are dominated by J. brevifolia however in the degenerative phases I. azorica is the dominant tree species. The cycle may be divided into an upgrade series (comprising the first two phases) and a downgrade series (between the mature and final degenerative phases). In these forests there was no climax micro-succession detected since changes in the dominant tree species occur in the degenerative phases. This paper brings the first evidence for the existence of a forest cycle in Macaronesian forests.
Segunda, 01 Junho, 2009
Ver todas as publicações