부산대학교 도서관

Sea level rise (SLR) imposes increasing salinity and inundation stresses in salt marshes which simultaneously face invasions by exotic plant species. We aimed to improve and apply knowledge on the ecophysiological responses of halophytes to SLR to conservation management of salt marshes. In a mesocosm experiment, we measured and compared phosphoenolpyruvate carboxylase (PEPC) activity and related functional traits of the California-native Spartina foliosa, invasive S. densifora and their hybrid S. densifora * foliosa in response to increasing levels of salinity and inundation. S. foliosa was moderately sensitive to salinity, showing a 57% reduction in PEPC specific activity from freshwater to hypersalinity. This native species compensated for the reduction of PEPC activity with increased salinity through 80% higher enzyme activation by phosphorylation. PEPC functional trait responses ofS.foliosawere mostly independent of inundation depth. In view of these results, managers should conserve undeveloped lands for accommodation space above current high tide lines to facilitate colonization of stress-tolerant S. foliosa. Our results on functional responses of PEPC traits recorded high sensitivity to salinity for S. densifora. This was reflected by 65% lower PEPC specific activity together with increasing accumulation of free proline (+96%) and total proteins (+23%) with elevated salinity. These results suggest prioritized eradication of S. densifora populations in brackish habitats. Measured PEPC responses support the high stress tolerance of the S. densifora * foliosa hybrid. PEPC traits for the hybrid were mostly independent of salinity and inundation. The hybrid showed higher PEPC-specific activity than S. foliosa (+70%) andS.densifora(+15%) in freshwater under intermediate inundation. Results suggest thateradication of the hybrid shouldbe the highest management priority. Our study shows that the responses of key functional physiological traits to environmental stresses serve as biological indicators that can guide ecosystem management practices in a scenario of climate change. Key words: environmental stress, hybrid, inundation, PEPC, polyploid, salinity, transgressive traits Editor: Kevin Hultine Received 29 December 2019; Revised 12 May 2020; Editorial Decision 13 May 2020; Accepted 14 May 2020 Cite as: Gallego-Tevar B, Peinado-Torrubia P, Alvarez R, Grewell BJ, Castillo JM (2020) From physiology to salt marsh management challenges with sea level rise: the case of native Spartina foliosa, invasive S. densifora and their hybrid. Conserv Physiol 8(1): coaa053; doi:10.1093/conphys/coaa053.
Introduction Sea level rise (SLR) due to global warming is increasing salinity, and inundation depth and duration in the world's salt marshes (IPCC, 2015). These environmental changes are highly significant [...]