The formation of a persistent soil seed bank could play an important role in determining the invasiveness of alien species as well as the resilience of native communities. However, knowledge of the role of the seed bank at different stages of the invasion process (naturalization and invasion) is scarce. To address this issue, we tested (1) whether seed bank type (transient vs persistent) and seed bank density (seeds per square meter) of invasive species differ from those of their non-invasive congeneric species, in their native and alien range, and (2) whether seed bank type and density differ between naturalized and non-naturalized species, at the global scale. To do so, we first compiled a global seed bank database comprising data for over 2000 species. We then combined this database with the Global Naturalized Alien Flora database (GloNAF), providing information on naturalization incidence (whether a species has become naturalized outside its native range) and extent (number of regions where a species has become naturalized) for 1917 species in over 11,000 records. We found that invasive species consistently had a higher probability of forming persistent seed banks as well as denser seed banks than their non-invasive congeners in their native range, but not in their alien range. Moreover, the probability of naturalization was higher in species forming persistent seed banks than those only forming transient ones, both in the native and alien distribution range. Seed bank density was also positively related with the probability of naturalization but not with naturalization extent, in the native and alien range. These findings indicate that a capacity to form a persistent seed bank is an important attribute for the establishment of alien species in new ranges (naturalization phase) but not for their spread (invasion phase). Ultimately, knowledge of the characteristics of the seed bank in the native range should be an important component of risk assessments.
Importance of the characteristics of soil seed banks in the invasion process
Gioria M;
2019-01-01
Abstract
The formation of a persistent soil seed bank could play an important role in determining the invasiveness of alien species as well as the resilience of native communities. However, knowledge of the role of the seed bank at different stages of the invasion process (naturalization and invasion) is scarce. To address this issue, we tested (1) whether seed bank type (transient vs persistent) and seed bank density (seeds per square meter) of invasive species differ from those of their non-invasive congeneric species, in their native and alien range, and (2) whether seed bank type and density differ between naturalized and non-naturalized species, at the global scale. To do so, we first compiled a global seed bank database comprising data for over 2000 species. We then combined this database with the Global Naturalized Alien Flora database (GloNAF), providing information on naturalization incidence (whether a species has become naturalized outside its native range) and extent (number of regions where a species has become naturalized) for 1917 species in over 11,000 records. We found that invasive species consistently had a higher probability of forming persistent seed banks as well as denser seed banks than their non-invasive congeners in their native range, but not in their alien range. Moreover, the probability of naturalization was higher in species forming persistent seed banks than those only forming transient ones, both in the native and alien distribution range. Seed bank density was also positively related with the probability of naturalization but not with naturalization extent, in the native and alien range. These findings indicate that a capacity to form a persistent seed bank is an important attribute for the establishment of alien species in new ranges (naturalization phase) but not for their spread (invasion phase). Ultimately, knowledge of the characteristics of the seed bank in the native range should be an important component of risk assessments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
