Shanze Li worked with Steve to synthesize 14 years of data on disturbance at the 8 GCE LTER fall monitoring sites dominated by Spartina alterniflora, and the paper was recently published in Ecosphere (Ecosphere 7(10):e01487. 10.1002/ecs2.1487). The results indicated considerable variation among sites and years in the amount of disturbance, and considerable variation between creekbank and midmarsh in the types of disturbance (wrack and slumping at the creekbank; snails in the mid-marsh). Barrier island sites experienced more disturbance than mainland sites. Wrack and snails and terminal slumping (when the plot ends up at the bottom of the creek) strongly affected biomass in affected plots, but overall, at the landscape level, disturbance did not have as strong an effect on fall biomass as abiotic conditions (salinity, sea level, temperature) did.
Tag Archives: Spartina alterniflora
Steve and Don Strong have been working with Yihui Zhang in China over the past few years. A paper based on this collaboration is now published in the Journal of Ecology. It describes phenotypic variation in exotic Spartina alterniflora in China. Spartina alterniflora is now widespread along the Chinese coast. Across this distribution, plants exhibit phenotypic variation in plant height, shoot density and sexual reproduction, but most of this variation disappears in a common garden, indicating that it is mostly due to plasticity rather than fixed genetic traits. In the native range, at least some latitudinal variation in Spartina traits has a fixed genetic basis. Some of the latitudinal patterns are similar to those found across latitude in the native range in the US, but others are different or have not been studied in the US. Thus, the latitudinal clines show some different patterns and have different underlying mechanisms in the native and exotic ranges.
Liu, W., Maung-Douglass, K., Strong, D.R., Pennings, S.C. and Zhang, Y. (2016). Geographical variation in vegetative growth and sexual reproduction of the invasive Spartina alterniflora in China. Journal of Ecology 104:173-181.
Photograph: Yihui and his students measure introduced Spartina alterniflora in China.
A new paper by Kazik Wieski and Steve Pennings in Ecosystems shows that Spartina alterniflora production in Georgia increases in years with high discharge from the Altamaha River during the late spring and summer. We examined 12 years of fall biomass data from 9 sites in the GCE-LTER domain, and found that river discharge increased productivity at all the sites, with plant biomass up to 3 times larger in high- versus low-discharge years. Coastal rainfall and year to year variation in sea level also affected plant growth to some extent, but not as consistently as river discharge. It is likely that all three factors affected porewater salinity, and that salinity was the proximate driver of plant production. We also found that hotter summers had lower productivity, because temperatures in GA can exceed the thermal optimum for Spartina alterniflora.
Future work by the GCE-LTER will use LandSat data to extend the S. alterniflora productivity record back in time (O’Donnell and Schalles) and will look at variation in productivity in other common marsh species (Pennings).
Kazimierz Wieski and Steven C. Pennings, 2013, Climate Drivers of Spartina alterniflora Saltmarsh Production in Georgia, USA. Ecosystems. DOI: 10.1007/s10021-013-9732-6.