NGVD

1999) occurred at higher elevations (>0.75 m NGVD) at SL1, 2, 3, 4, and ML compared with CM, TE1 and TE2.

virginica (to 100%) occurred at elevations of >0.60 m NGVD at the least muted sites (SL1, 2, 3, and ML), but was virtually absent at elevations of >0.60 m NGVD at the most muted sites (CM, TE1, and TE2).

These species were present in high cover (70-100%) at CM, TE1, and TE2 at elevations (0.90-1.20 m NGVD) occupied entirely by marsh plants at SL1, 2, 3 and 4.

4, Page, unpublished data) the highest observed tidal water level of 2.3 m NGVD measured at Scripp's Pier on 8 August 1983 (MEC, 1993).

The lower elevational limits of Parapholis incurva and transition/upland species were correlated with variation in the degree of tidal muting across sites (Table 1) and with the elevation reached by the highest tide (1.4 m NGVD at La Jolla).

Of 179 Lycium plants sampled within the belt transects, 50% grew between 1.5 and 2.0 m NGVD and 94% grew in a 1.1-m elevation band (1.4-2.5 m NGVD).

All 272 Lycium plants sampled randomly within three large areas of Tijuana Estuary occurred within the same elevation band (1.4-2.5 in NGVD).

A 27-cm anomaly during high tide would flood the ecotone to approximately 1.59 m NGVD. The water level during one high tide in January 1983 reached 1.66 m NGVD (Fig.

High spring tides, which occur biweekly during the rainy season, would kill seedlings below about 1.4 m NGVD. The lower distributional limit of Lycium is probably determined by regular tidal inundation.