Species co-existence in an Australian subtropical rain forest: evidence for compensatory mortality
1999; Wiley; Volume: 87; Issue: 2 Linguagem: Inglês
10.1046/j.1365-2745.1999.00360.x
ISSN1365-2745
Autores Tópico(s)Forest Management and Policy
Resumo1 The relationship between the distribution of juveniles and conspecific trees was examined in a subtropical rain forest in south-east Queensland (Australia) to determine the role of compensatory mortality in maintaining the species richness of the forest. 2 Two species, which were among the most common canopy trees at the site, showed some evidence that the abundance of juveniles was reduced in the vicinity of conspecific trees. This spacing effect was particularly marked in Sloanea woollsii, but also present in Doryphora sassafras. The probability of finding juveniles of these species decreased as a function of (i) decreasing distance from the quadrats to the nearest conspecific tree and (ii) increasing density of conspecific trees (Sloanea woollsii only). In addition, these species accounted for a smaller proportion of the total number of juveniles close to conspecifics than they did at greater distances. 3 In contrast, the juveniles of a number of other species were more commonly found in the vicinity of conspecific trees. Two species had juveniles that were comparatively poorly dispersed: Acmena ingens and Polyosma cunninghamii juveniles were seldom found more than 10 m and 15 m away from conspecific trees. 4 Compensatory mortality might be necessary to prevent other species from being excluded by the two most common species, but it does not appear to be sufficient to explain how the majority of species co-exist with each other.
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