Writing Scientific Research Articles: Strategy and Steps

Conclusions
In our system, neither disturbance nor propagule input alone
was sufficient to maximize invasion success (i.e. establishment
probability and invader population density). Increasing prop-
agule pressure had relatively little effect on total recruitment
in control plots (Fig. 1a), though at high levels it ultimately
overcame space limitation and ensured successful invasion
(Fig. 3). However, even at high levels of propagule input, final
S. muticum
 density was low in the absence of disturbance
(Fig. 1b). Based on our experimental results alone, we might
have predicted strong effects of both molluscs and urchins on
the S. muticum invasion in the long term. However, the simula-
tion model suggested that these two natural disturbance
agents should have different effects on long-term invasion due
to differences in the spatial structure of these disturbances.
The model results demonstrate that caution should be exercised
when extrapolating the results of short-term disturbance
experiments over longer time intervals. In this marine com-
munity invasion success was co-regulated by propagule pressure
and biotic resistance. Our results underscore the importance
of considering interactive effects when making predictions
about invasion success.