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Figure 3. Temporal patterns of cover for
Lonicera japonica
and
Rosa multiflora
during succession
within the BSS data. Arrows indicate the time span over which community dynamics in association
with each invasion were assessed.
We determined the associations between total species richness and
R. mul-
tiflora
and
L. japonica
cover within plots at the midpoint of each invasion. This
analysis is analogous to the one-time community sampling studies frequently
conducted to assess the impacts of exotic plant invasion. For both species,
there was a significant, negative relationship between the cover of the invad-
ing species and the total species richness of each plot (Fig. 4). This relation-
ship by itself does not elucidate any mechanisms that generate the observed
pattern, but suggests interaction between the community and the invader.
For all plots that were uninvaded at the beginning of the observation period,
we determined the relationship between initial species richness and the proba-
bility of subsequent invasion during the observation period for each species.
This determines whether the invasibility of plots changes with species rich-
ness. For both species, plots with higher initial species richness were more
likely to become invaded over the observation period than were plots with
lower species richness (Fig. 5). The dynamics demonstrated by these species
are in the opposite direction of most theoretical and experimental results,
which show negative associations between invasibility and diversity. The
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