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ARS Home » Pacific West Area » Burns, Oregon » Range and Meadow Forage Management Research » Research » Publications at this Location » Publication #405206
Research Project: Restoration and Conservation of Great Basin Ecosystems

Location: Range and Meadow Forage Management Research

Title: Photosynthetic resilience of Elymus elymoides and Pseudoroegneria spicata seedlings following acute water stress

Author
item O'Connor, Rory
item FOX, VICTORIA - Bureau Of Land Management
item Hamerlynck, Erik

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2024
Publication Date: 4/13/2024
Citation: O'Connor, R.C., Fox, V.G., Hamerlynck, E.P. 2024. Photosynthetic resilience of Elymus elymoides and Pseudoroegneria spicata seedlings following acute water stress. Rangeland Ecology and Management. 94:195-198. https://doi.org/10.1016/j.rama.2024.03.012.
DOI: https://doi.org/10.1016/j.rama.2024.03.012

Interpretive Summary: Bunchgrass seedlings often die from the soil surface quickly drying out in spring which limits restoration success in semi-arid rangelands. We studied how two native bunchgrass species (Elymus elymoides, Pseudoroegneria spicata) would recovery physiologically to an acute water stress. We found that both species were able to recover physiologically, but they had different recovery trajectories. Elymus elymoides recovered fully within 1 day, and that Pseudoroegneria spicata took 6 days for 50% recovery to acute water stress. These results suggest that Elymus elymoides seedlings are more physiologically resilient to acute water stress than Pseudoroegneria spicata, which has implications for restoration planning and native plant breeding.

Technical Abstract: Demographic studies suggest that mortality of emerging bunchgrass seedlings limits restoration success across North American cold desert rangelands, but how variation in seedling resilience to ecophysiological stress contributes to this is unclear. We measured light-saturated photosynthetic rate (Asat), apparent CO2 assimilation quantum yield (FCO2), and light-adapted PSII yield (FPSII) of seedlings from two native perennial bunchgrasses (Elymus elymoides, Pseudoroegneria spicata) during and in recovery from acute water stress (6% soil moisture). All seedlings of both species survived the 14-d dry-down and recovery, and both had ~95% reduction in Asat and FCO2 by day 3 of the dry-down but had divergent recoveries from the acute water stress. E. elymoides took a single day to recover Asat and FCO2 to prestress levels, while it took P. spicata 6 d to have 50% recovery from acute water stress. Especially notable is that after reduction in FPSII on d 7 of the dry-down, E. elymoides recovered within 1 d at a lower FPSII compared with pretreatment, while P. spicata had an additional 1-d lag in FPSII recovery. These results suggest that E. elymoides (Turkey Lake germplasm) seedlings are more physiologically resilient to acute water stress than P. spicata (Anatone germplasm), which has implications for restoration planning and native plant breeding.