TY - JOUR
T1 - Comparison of coastal dune scrub in israel and california
T2 - Physiognomy, association patterns, species richness, phytogeography
AU - Barbour, Michael G.
AU - Shmida, Avi
AU - Johnson, Ann F.
AU - Holton, Booker
PY - 1981/1/1
Y1 - 1981/1/1
N2 - Coastal dune scrub near Caesarea, Israel was quantitatively described from quadrats placed in 10 sites, ranging from pioneer to near-climaxs communities. Sampling intensity was greatest in a mixed shrub community (Artemisia monosperma, Helianthemum stipulation, Retama raetam) characteristic of stabilized dunes in the study area. Artemisia canopy had much less effect on the distribution of understory species than Retama and Helianthemum canopies. The sampled flora of 131 taxa was dominated by Legumi- nosae, Gramineae, and Compositae. About 45% of the flora had Mediterranean affinities, 17% coastal (mostly endemic to Israel), and 16% desert. California dune scrub from Point Reyes and Vandenberg areas was also sampled. The two sites are climatically similar to Caesarea, but both experience summer fog which lowers summer temperatures below those at Caesarea. Climax scrub was dominated by Lupinus arboreus and Haplo- pappus ericoides at Point Reyes, by H. ericoides associated with L. chamissonis, Core- throgyne filaginifolia, and Senecio blochmanae at Vandenberg. Its physiognomy was only superficially similar to the Caesarea mixed shrub: Three canopy layers (shrubs 1 m tall + subshrubs + herbs); somewhat open (75% cover); perennial leaves typically soft, evergreen, small or dissected, and pubescent. In contrast to Israel, annuals contributed very little cover and stands were dominated instead by shrubs and chamaephytes. Sclero- phylls and succulents were more common in California. One-third of the sampled 86 taxa were Compositae. About 37% of the flora had Mediterranean (=Californian floristic province) affinities and a similar fraction was strictly coastal. Only 6% had desert affinities and 14% were introduced. The percentage of endemism was 2-3 times higher in the Californian dunes. We concluded that the level of convergence attained by these two disjunct vegetation types was superficial, despite similarities in their present environments and physiognomies.
AB - Coastal dune scrub near Caesarea, Israel was quantitatively described from quadrats placed in 10 sites, ranging from pioneer to near-climaxs communities. Sampling intensity was greatest in a mixed shrub community (Artemisia monosperma, Helianthemum stipulation, Retama raetam) characteristic of stabilized dunes in the study area. Artemisia canopy had much less effect on the distribution of understory species than Retama and Helianthemum canopies. The sampled flora of 131 taxa was dominated by Legumi- nosae, Gramineae, and Compositae. About 45% of the flora had Mediterranean affinities, 17% coastal (mostly endemic to Israel), and 16% desert. California dune scrub from Point Reyes and Vandenberg areas was also sampled. The two sites are climatically similar to Caesarea, but both experience summer fog which lowers summer temperatures below those at Caesarea. Climax scrub was dominated by Lupinus arboreus and Haplo- pappus ericoides at Point Reyes, by H. ericoides associated with L. chamissonis, Core- throgyne filaginifolia, and Senecio blochmanae at Vandenberg. Its physiognomy was only superficially similar to the Caesarea mixed shrub: Three canopy layers (shrubs 1 m tall + subshrubs + herbs); somewhat open (75% cover); perennial leaves typically soft, evergreen, small or dissected, and pubescent. In contrast to Israel, annuals contributed very little cover and stands were dominated instead by shrubs and chamaephytes. Sclero- phylls and succulents were more common in California. One-third of the sampled 86 taxa were Compositae. About 37% of the flora had Mediterranean (=Californian floristic province) affinities and a similar fraction was strictly coastal. Only 6% had desert affinities and 14% were introduced. The percentage of endemism was 2-3 times higher in the Californian dunes. We concluded that the level of convergence attained by these two disjunct vegetation types was superficial, despite similarities in their present environments and physiognomies.
UR - http://www.scopus.com/inward/record.url?scp=9644312240&partnerID=8YFLogxK
U2 - 10.1080/0021213X.1981.10676919
DO - 10.1080/0021213X.1981.10676919
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AN - SCOPUS:9644312240
SN - 0021-213X
VL - 30
SP - 181
EP - 198
JO - Israel Journal of Botany
JF - Israel Journal of Botany
IS - 4
ER -