Modeling and predicting changes in dormancy in soil seed banks

ROBERTO LUIS BENECH-ARNOLD; DIEGO BATLLA

Salt lake City, Estados Unidos de Norteamerica

Congreso; Third International Society for Seed Science Meeting on Seeds and the Environment; 2010

International Seed Science Society

Dormancy can be defined as an internal condition of the seed that impedes its germination under otherwise adequate hydric, thermal and gaseous conditions (Benech-Arnold et al. 2000). Dormancy can be classified in primary and secondary dormancy. Primary dormancy refers to the innate dormancy possessed by seeds when they are dispersed from the mother plant. Secondary dormancy refers to a dormant state that is induced in non-dormant seeds by unfavorable conditions for germination, or re-induced in once-dormant seeds after a sufficiently low dormancy had been attained. Predicting seed-bank dormancy level is important because timing and extent of seedling emergence in the field is strictly related to the dormancy state of the seed-bank. The possibility of predicting the dormancy state of the seed-bank, and consequently, timing and extent of seed emergence, has many practical applications. For example, in relation to increasing the efficacy of weed control methods, assessing both timing and extent of weed emergence through predictive models, is of capital importance (Batlla and Benech-Arnold 2007). In addition, predictive models can help us to design practices for managing native or introduced plant populations (Allen et al. 2007). To accomplish this goal, the following steps need to be followed: first, the effect of the different environmental factors on the dormancy level of buried seeds must be comprehensively understood; second, the effect of those factors on the dormancy level of the seed-bank population must be quantified; third, the developed quantitative relationships must be included in a consistent modeling framework. In the present paper we show examples of practical approaches to accomplish these three steps.