Vernal pools

Figure 23 (a) Mima mounds (grass-covered areas) and vernal pools (gravel veneered low areas) on a Plio-... 

Holland R. F. (1996) Great Valley vernal pool distribution, Photorevised 1996. In Ecology, Conservation, and Management of Vernal Pool Ecosystems, Proceedings of a 1996 Conference, California Native Plant Society, Sacramento, CA (eds. C. W. Witham, E. T. Bander, D. Belk, W. R. Ferren, Jr., and R. Omduff), pp. 71 -75. 

Vernal pools are small depressional wetlands that range in size from small pockets saturated with water to shallow lakes. These wetlands are found in gently sloping grassland landscapes with Mediterranean climate, such as in the West Coast. Many of these wetlands in California have been drained for development. During any given single season, these wetlands may fill and dry several times. The subsurface is either bedrock or a clay layer that helps to hold the water. 

F9. Vernal Pools. For use in LRRs B, C and D. In closed depressions snbject to ponding, presence of a depleted matrix with 60% or more chroma 2 or less in a layer 5 cm (2 in.) thick entirely within the upper 15 cm (6 in.) of the soil surface. 

Fig. 5. The rate of chlorophyll accumulation in etiolated seedlings exposed to continuous light for 5 d. Wild type, lut2, abal and Iul2aba I etiolated tissue culture-grown seedlings were vernalized, germinated in the dark for 3 d and then transferred to continuous light. At each time point, 2 replicate extracts of 10 pooled seedlings were analyzed and the chlorophyll content expressed on a per plant basis (pg/seedling). Standard deviations greater than the size of the symbol are shown.

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