Document Detail

It is risky out there: the costs of emergence and the benefits of prolonged dormancy.
MedLine Citation:
PMID:  23274621     Owner:  NLM     Status:  Publisher    
Prolonged dormancy is a stage in herbaceous perennial plants in which some individuals remain alive below ground for one or more growing seasons instead of emerging. Prolonged dormancy is puzzling, because foregoing opportunities for growth and reproduction seems costly. However, studies have shown that it buffers plants from the negative consequences associated with environmental stochasticity, suggesting that dormancy is a beneficial strategy to avoid the risks of stress above ground. If so, emergence during unfavorable conditions should have significant costs. Here, we test the hypothesis that emergence during times of stress has negative demographic consequences in a native perennial forb, Astragalus scaphoides, and investigate the potential underlying physiological mechanisms. We measured plant responses to a severe seasonal drought and an experimental defoliation to ask: (1) How do emergent plants respond to above-ground stress? (2) Do these responses have negative demographic consequences? and (3) Based on these responses, does stress increase the risk of emergence? Plants showed remarkable physiological tolerance to stress in the short term: high temperatures and low moisture did not have a strong effect on photosynthesis rates, and neither drought nor defoliation significantly impacted stored resources. However, stress did result in demographic costs for emergent plants relative to plants experiencing more favorable conditions. Drought resulted in decreased flowering probabilities relative to the long-term average and defoliation significantly increased mortality rates. These results demonstrate that the risk of emerging and experiencing stress entails considerable costs, supporting the hypothesis that prolonged dormancy is a beneficial strategy to avoid such risk.
Jennifer R Gremer; Anna Sala
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-1-1
Journal Detail:
Title:  Oecologia     Volume:  -     ISSN:  1432-1939     ISO Abbreviation:  Oecologia     Publication Date:  2013 Jan 
Date Detail:
Created Date:  2012-12-31     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0150372     Medline TA:  Oecologia     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Division of Biological Sciences, University of Montana, Missoula, MT, USA,
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Predicted end-tidal sevoflurane concentration for insertion of a Laryngeal Mask Supreme: a prospecti...
Next Document:  The distribution of cardiac troponin I in a population of healthy children: Lessons for adults.