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Seed Germination Ecology of Hawaiian Montane Species
Department of Plant and Soil Sciences
The montane zone of Hawaii ranges in elevation from 500-2,700 m, and it has a variety of plant communities, including dry grasslands, dry shrublands, dry forests, mesic forests, wet herblands, wet sedgelands, wet mixed communities, wet shrublands, and wet forests. This zone has been highly disturbed by humans; consequently, many community types as well as individual species have become very rare. Therefore, conservation efforts involve habitat restoration as well as protection and propagation of rare species.
A significant problem in restoration projects frequently is lack of plants of appropriate species for re-introduction. The ultimate goal is to provide people who are propagating Hawaiian native species, as well as those who are involved in habitat restoration, with a database for montane species that includes (1) the seed dormancy class, and (2) information on dormancy breaking and germination requirements of the seeds. Not only do plant propagators need to be able to break seed dormancy, but people involved in managing sites for long-term persistence of a species need to understand what natural environmental factors are required to break dormancy.
The purpose is is learn more about seed dormancy and germination and thus to provide people who are propagating Hawaiian native species for restoration efforts with a database for montane species that includes (1) the seed dormancy class, and (2) information on dormancy breaking and germination requirements of each species.
2011 Project Description
The ultimate goal is to provide people who are propagating Hawaiian native species and/or those who are involved in habitat restoration and conservation with
(1) research-based information on dormancy-breaking and germination requirements of as many montane species as possible and
(2) new tools, i.e., a database of seed dormancy class of montane species and a "move-along experimental" technique that is appropriate for Hawaiian montane species.
This information will enhance the ability of propagators to grow plants from seeds and of preservation managers to time events such as prescribed fire to optimize conditions for seed survival, dormancy break, and germination.
About 75 species from Hawaii have been studied in my lab. Combining these data with those of done seed storage in Alvin Yoshinaga's laboratory in Hawaii and information in the book by J. L. Culliney and B. P. Koebele (1999) entitled "A native Hawaiian Garden" (University of Hawaii Press, Honolulu), I have been able to determine the class of dormancy (or in some species the presence of nondormancy) for 158 species from the montane zone in Hawaii. The results are: 10.8% (17 species) nondormant (ND); 8.2% (13) morphophysiological dormancy (MPD); 69.6% (110) physiological dormancy (PD); 8.2% (13) physical dormancy (PD); and 0.6% (1) combination of physical and physical dormancy (PY+PD).
Use of the move-along experiment has provided much new information about species whose seeds have physiological dormancy. In 20 of the 38 Hawaiian species whose seeds had PD, some seeds had germinated after 4 wk at high (25/15, 20/15 C) but not at low (20/10, 15/6 C) temperatures.
In the other 18 species with PD, no germination had occurred after 4 wk at any temperature. After 6-12 wk of incubation, however, seeds of the 18 species began to germinate at one or more temperatures, and in a few species, e.g., Clermontia pyrularia, low temperatures were more favorable for germination than high temperatures.
Activities during 2011 include:
(1) Lecture: "How seed dormancy studies serve plant conservation," Ohio State University, 3 March 2011,
(2) Short course "Breaking dormancy and germinating seeds of wild species" Ohio State University, 5 March 2011 and
(3) Lecture: "How seed dormancy studies serve plant conservation.
Using information on classification, biogeography and phylogeny of seed dormancy to facilitate propagation of plant species for restoration" Tarim University, Ala`er, Xinjiang, China, 17 June 2011
Gama-Arachchige, N. S., Baskin, J. M., Geneve, R. L. and C. C. Baskin, C. C. (2011). Acquisition of physical dormancy and ontogeny of the micropyle-water-gap complex in developing seeds of Geranium carolinianum (Geraniaceae). Annals of Botany 108: 51-64.
Chien, C.-T., Chen, S.-Y., Tsai, C.-C., Baskin, J. M., Baskin, C. C. and Kuo-Huang, L.-L. (2011). Deep simple morphological dormancy in seeds of two Viburnum species, with special reference to shoot growth and development inside the seed. Annals of Botany 108: 13-22.
Adams, C. A., Baskin, J. M. and Baskin, C. C. (2011). Using size-class structure to monitor growth of underdeveloped embryos in seeds of three Aristolochia species: implications for seed ecology. Seed Science Research 21: 159-164.
Chien, C.-T., Chen, S.-Y, Baskin, J. M. and Baskin, C. C. (2011). Morphophysiological dormancy in seeds of the ANA grade angiosperm Schisandra arisanensis (Schisandraceae). Plant Species Biology 26: 99-104.