| Abstract Detail
Ecological Section Forbis, Tara [1]. Germination phenology of some Great Basin native annuals. Great Basin native plant communities are being replaced by the annual invasive cheatgrass (Bromus tectorum). Although perennials dominate these communities, native annuals are present in many sites, particularly in previously uninvaded, recently burned sagebrush sites. Cheatgrass exhibits a germination syndrome that is characteristic of facultative winter annuals. Because germination timing is an important determinant of competitive interactions, I used a growth chamber experiment to determine whether a suite of native annuals exhibit winter or spring annual germination syndromes. Amsinckia intermedia (Boraginaceae), Amsinckia tesselata (Boraginaceae), Blepharipappus scaber (Asteraceae), Descurainia pinnata (Brassicaceae), Eriastrum sparsiflorum (Polemoniaceae), Lappula occidentalis (Boraginaceae), Mentzelia albicaulis (Loasaceae), Nicotiana attenuata (Solanaceae), and Plagiobothrys tenellus (Boraginaceae) were checked for responsiveness to light, chill, and dry after-ripening. Light responsiveness was tested in a chamber under a constant 20 ºC. Dry after-ripening was done in sealed glass jars in a 40ºC incubator for 4 weeks, and cold stratification was at 2ºC for 8 weeks. Species differed in their germination requirements, with some having no dormancy-breaking requirement, some being responsive to cold wet stratification, and some requiring dry after-ripening. Species which are responsive to dry after-ripening would be expected to have germination phenology most similar to cheatgrass, a trait that would allow them to compete with the invasive.
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1 - USDA-Agricultural Research Service, Exotic and Invasive Weeds Research Unit, 920 Valley Rd., Reno, NV, 89512, USA
Keywords:
Germination
dormancy
Seed
Invasive Species
annual.
Presentation Type: Poster:Posters for BSA Sections
Session: P1
Location: Event Tent/Cliff Lodge
Date: Monday, July 27th, 2009
Time: 5:30 PM
Number: P1EC009
Abstract ID:304 |
