H. Rosch et al., PREDICTING COMPETITIVE INTERACTIONS BETWEEN PIONEER PLANT-SPECIES BY USING PLANT TRAITS, Journal of vegetation science, 8(4), 1997, pp. 489-494
A competitive effect hierarchy for 15 Namaqualand pioneer plant specie
s was established by using the mean mass of the phytometer (Dimorphoth
eca sinuata) when grown in combination with itself and 14 other specie
s. There were no clear groupings of species in the hierarchy. This com
petitive hierarchy (gradient) indicated which species are strong compe
titors (resulting in a low phytometer mass) with D. sinuata and which
species are weak competitors (resulting in a high phytometer mass). Ea
ch plant species has a certain combination of plant traits which deter
mines its life history strategy and competitive ability. Regressions o
f various plant traits (measured on plants grown singly) against phyto
meter biomass indicated which traits were significantly correlated. Th
e traits, most being size-related, were: maximum shoot mass, total mas
s, stem mass, reproductive mass, leaf area, stem allocation, specific
leaf area (SLA), vegetative height x diameter, leaf area ratio (LAR);
and mean number of days to flower initiation. A forward stepwise multi
ple regression of the significant traits was used to determine an equa
tion to predict competitive effect.