Propagule Pressure - Concepts

Concepts

One important concept of propagule pressure is how it can be used to predict and or prevent invasions of nonnative species in high risk locations. As invasion rates increase and biodiversity decreases, the probability of non-native establishment needs to be more accurately measured (Leung et al., 2004). Once estimation rates of species invasion success are better known, prevention efforts can be better implemented (Leung et al., 2004). To properly understand propagule pressure it is also important to realize that it is actually in flux within nature. In general, the probability of establishment will always be higher whenever propagule pressure is higher (Leung et al., 2004). If pressure is extremely low it is likely that the species’ population will be too small to detect. When this is the case detailed information on rates of population introduction and size are difficult to obtain (Leung et al., 2004).

In most studies a direct relationship is observed, the higher the propagule pressure the higher the success of the invasion. It is worthy to note, though, that in Britton-Simmons and Abbott’s study (2008) of the successfulness of seaweed establishment in marine algal communities, propagule pressure was not sufficient to maximize invasion success. They found that resource availability had to coincide with invasion time and was a limiting factor to seaweed success (Britton-Simmons et al., 2008).