Spatial patterns of trees and juveniles in a laurel forest of Tenerife, Canary Islands

Abstract

Spatial patterns are important characteristics of the forest and they can reveal such things as successional status and ecological characteristics of the species. We tested the hypothesis that spatial distribution will be different, depending on whether the species is intolerant or tolerant to shade. We assessed the spatial distribution of trees (> 4 cm dbh) and juveniles in eight laurel forest plots. A univariate spatial analysis (performed with Ripley’s K1) showed that all tree species have significant aggregation at short distances (2 m). Nevertheless, two groups of species could be differentiated: Erica scoparia, Myrica faya and Ilex canariensis showed a tendency for aggregation at large distances (larger than 6 m) while L. azorica and Prunus lusitanica showed aggregation only at shorter distances. Ripley’s Bivariate K1,2 analyses showed no significant differences in the spatial distribution of analyzed species pairs from a null model. Only Laurus azorica had a sufficient sample size for analysis of juvenile distribution. A univariate analysis revealed that L. azorica seedlings (stems < 50 cm high) were clumped in some plots up to 5 m, but this was not consistent. Saplings (stems > 50 cm high and < 4 cm dbh) did not show strong clumping even at short distances. L. azorica saplings had no significant aggregation with, nor repulsion from, adults of the same or different species. Spatial patterns of the species should be considered in the development of restoration plans of the laurel forest 90% of which has disappeared or been intensively disturbed on Tenerife Island.