Critical conditions for successful regeneration of an endangered annual plant, Cryptantha minima: A modeling approach

• Published in: Journal of arid environments 2009-09, Vol.73 (9), p.872-875
• Main Authors: Wei, Y., Bai, Y., Henderson, D.C.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; annuals; Biological and medical sciences; Cryptantha; Cryptantha minima; drought; endangered species; Fundamental and applied biological sciences. Psychology; General aspects. Techniques; Methods and techniques (sampling, tagging, trapping, modelling...); seed dormancy; Seed germination; Snowmelt; Synecology; temperature; Terrestrial ecosystems; Thermal time model; Tiny cryptanthe; water potential; water stress
• ISSN: 0140-1963; 1095-922X
• DOI: 10.1016/j.jaridenv.2009.03.008

Tiny cryptanthe ( Cryptantha minima Rydb.) is an endangered annual plant adapted to prairie sand dunes of Canada. Thermal time and hydrothermal time models were used to quantify the effect of temperature and water potential on seed germination and to relate it to field conditions. Tiny cryptanthe seeds had a base temperature of −3.9 °C for germination. Final germination percentage was highest at temperatures near the freezing point. Seeds required approximately 130.6 °C d to reach 50% germination under optimal water conditions. Seed germination was sensitive to water stress and large seeds had lower germination than small ones especially at reduced water potentials and higher temperatures. The high potential germination and low seed dormancy indicate that tiny cryptanthe lacks a dormancy mechanism, but the unique germination response to temperature enables it to fully utilize water from spring snowmelt before drought in the summer. Future climate change with higher temperatures could reduce regeneration success of this species unless there is an associated increase in winter and spring precipitation.