Baldcypress trees are crucially important throughout the Southeastern United States because of their role in carbon storage and ability to protect coastal areas from storm damage. As sea level rise occurs, establishment of new trees is particularly difficult due to inundation and salt stress. Land-use and salinity are major factors affecting hydrology and lead to the degradation of baldcypress swamps. We examined the diversity of bacterial and fungal endophyte communities in 184 root and rhizosphere samples along four salinity/land-use gradients established 11 years ago in Louisiana, Georgia, and South Carolina to examine long-term trends on how baldcypress swamps are affected by climate change-induced salinization and flood regime. In this study, we used culture-dependent and culture-independent sampling to begin the process of characterizing the diverse bacterial and fungal endophytes present in baldcypress root systems along salinity gradients.
Results/Conclusions
Root endophytes were abundant and diverse in baldcypress roots on all transects. Bacterial abundances were similar among the four transects while significant site differences were observed for fungal endophyte abundances. Bacterial endophyte abundance showed a strong, positive correlation with increasing salinity (r=0.61, p=0.03). Fungal endophyte abundance showed a weak, positive correlation with increasing salinity (r=0.30, p=0.34). These results suggest that baldcypress trees may rely more on symbiotic relationships in higher salinity habitats.