Figure 1.
Experimental setup showing the three different treatments of the experiment: the priority effect treatment of arrival order, the different density treatment and the sowing interval treatment.
Priority effects of early sowing of one PFT are shown with a plant functional group symbol without a circle, and later sowing of the remaining two PFTs are shown in grey circles. For the priority effect treatment legumes, forbs or grasses were sown a number of weeks before the other two groups. Density levels were 1.5, 2.5 and 5−2, and sowing intervals were three- and six-weeks between first PFT sown and remaining PFTs. Controls involved all PFTs being sown together at the same time. Number of replicates is shown in bold next to each treatment.
Table 1.
ANOVA table for the effects of experimental treatments on aboveground biomass.
Figure 2.
Sowing legumes first (L-first) produced the highest aboveground biomass, especially in the six-week interval treatment.
Density had weaker effects on biomass than the priority effect treatment or sowing interval. Data show mean aboveground biomass (±1 SE) in the priority treatment separated into the three density levels. This is shown per sowing interval treatment with panel a) describing the three-week sowing interval and panel b) the six- week sowing interval treatment. For the priority effects treatment F, G and L-first = forbs-, grasses- and legumes-first. Replicates are n = 4 for main treatments and n = 2 or 1 for the controls in the six-week interval and three-week interval respectively.
Figure 3.
Effects of early sowing of one PFT (F, G and L-first = forbs-, grasses- and legumes-first) on the functional composition of communities in pots.
Relative cover of PFTs (forbs, grasses, legumes) in pots were derived from individual species cover values summed and are depicted separately for each of the three densities: (a) 1.5 g m−2, (b) 2.5 g m−2 and (c) 5 g m−2 for both sowing intervals (three and six weeks, in vertical columns) from vegetation assessments at peak biomass development. The data show mean values (±1 SE); n = 4 for all treatments (except for controls where n = 3).
Figure 4.
Effect of experimental treatments on the similarity of the resulting communities.
Dendrogramm showing between group linkages for all replicates of the treatment groups: density (1.5, 2.5 and 5 g m−2; sowing interval (3- and 6- week) and the priority effects treatment F, G and L-first = forbs-, grasses- and legumes-first as a result of a cluster analysis performed on data for relative individual species cover of every single pot in June 2011. As a measure of distance between groups Pearsons correlation coefficient was taken.
Figure 5.
Effects of density and sowing interval on number of plant individuals per pot.
For the priority effects treatment (PE) F, G and L-first = forbs-, grasses- and legumes-first. Values are mean number of plant individuals per pot with the PFT sown first on the x-axis and for all three densities for both groups sown with a three week interval (a) and a six week interval (b) between sowing of the first and remaining PFTs. (n = 4; ±1 SE).