Contrasting latitudinal clines of nematode diversity in Spartina alterniflora saltmarshes between native and introduced ranges

Aim: Introduced species may display or foster novel latitudinal clines because they are not well adapted to their new habitats. We tested the hypothesis that the latitudinal cline in nematode diversity in saltmarshes would differ between the native (United States) and introduced (China) ranges of Spartina alterniflora.

Location: East Coasts of the United States (30.32°N to 43.33°N) and China (30.36°N to 39.14°N).

Methods: We extracted nematodes from soil samples collected at 32 sites along the United States East Coast and 41 sites along the Chinese coast. We compared latitudinal patterns in nematode diversity and composition between the native and introduced ranges.

Results: In the native range of S. alterniflora, nematode richness at lower latitudes was almost twice as high as that at higher latitudes. In contrast, we found no latitudinal pattern in nematode richness or diversity in the introduced range of S. alterniflora. Nematode genus richness at all sites in China was abou...