The trade-off between dispersability and longevity - an important aspect of plant species diversity

Authors


Corresponding author; Permanent address: Department of Ecological Botany, Uppsala University, Villavägen 14, S-752 36 Uppsala, Sweden; Tel. +46 18 4712869; Fax +46 18 553419; E-mail johan.ehrlen@vaxtbio.uu.se

Abstract

Abstract. Local presence of plant species is determined by population colonizations and extinctions. All traits that influence the capacity of individuals to colonize patches and survive within patches, are therefore important for community diversity. Spatial models can explain the coexistence of species provided that the inferior competitor has a greater spatial mobility and thereby can avoid competition. We searched the literature for empirical evidence for such trade-offs and included all available information on correlations between traits associated with the capacity to colonize and traits promoting the ability to survive.

A lower reproductive effort of a species is associated with a longer life span and a higher competitive ability. Morphological adaptations for dispersal are less common in species which better tolerate stress, that are better competitors or possess seed dormancy. Such patterns suggest that species that are good survivors may have a limited ability to colonize new patches and vice versa. A negative correlation between dispersability and longevity has important effects on the regional dynamics of single species as well as on the coexistence of species. From a conservation perspective differences in the colonization capacity among species imply that restoration of plant biodiversity must not only focus on conditions within patches, but also consider the spatial arrangement of patches in order to enable plants to bridge gaps in time and space.

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