Maritime Chaparral No real definition has stabilized for maritime - PDF document

The Ecology and Conservation of California's Maritime Chaparral Evolution and distribution of Archtostaphylos Tom Parker Maritime Chaparral No real definition has stabilized for maritime chaparral. There is Understanding Maritime a continuum of chaparral Chaparral types distributed along the Post-fire at Ft.Ord coast of California. Using Arctostaphylos as the road to and from confusion Summer fog is the one characteristic that links these chaparral types together. Pfeiffer Rock ? Origin within the Ericaceae • The Arbutoideae is a subfamily of the Ericaceae, a widespread and diverse family. The family itself dates beyond 100 MYBP, The recent Arctostaphylos (manzanitas) radiation in and some estimates California has resulted in a confusing group for most place it older. people. As a principal dominant of maritime chaparral, one question is where did all these manzanitas come from ? One theory proposed relationships within the family based upon their fungal root mutualists, or mycorrhizae . Using Suggesting single origins for the various mycorrhizal molecular types within the family, the Arbutoideae comes out as sequence one of the oldest lineages. data, these relationships within the Ericaceae were confirmed. Elkhorn Slough Coastal Training Program Workshop January 17, 2003 1

The Ecology and Conservation of California's Maritime Chaparral Evolution and distribution of Archtostaphylos Tom Parker The subfamily Arbutoideae contains 6 What are the relationships among the genera within genera. These genera are found in the the Arbutoideae? northern hemisphere, with most species confined to North America. • Arbutus ~12 species • Arctostaphylos ~60-90 species • Arctous 2 species • Comarostaphylis ~16 species • Ornithostaphylos 1 species • Xylococcus 1 species Molecular sequences suggest Arbutus as the Arbutus basal genus for the subfamily, and Arctostaphylos as the most derived. • As the oldest lineage within the subfamily, Arbutus fossils date back over 50 MYBP. • Arbutus is divided into 2 clades, one found in western N. America including Mexico, • …and one in the Mediterranean Basin. Comarostaphylis Arbutus A. arizonica Most species of Comarostaphylis are found in the Mexican highlands and are diverse with respect to floral and fruit color, pubescence, and size. One species occurs in Southern A. menziesii California ( C. diversifolia ). North America contains roughly 12-14 species, most of which are restricted to Mexico. Three species are found in the Mediterranean Basin. Life forms A. unedo range from shrubs to trees. Elkhorn Slough Coastal Training Program Workshop January 17, 2003 2

The Ecology and Conservation of California's Maritime Chaparral Evolution and distribution of Archtostaphylos Tom Parker Xylococcus Arctous • Xylococcus is a monotypic • Arctous rubra is found in genus. boreal forest areas of North Swedish tundra with Arctous America . •Restricted to S. California and northern Baja, X. bicolor was originally placed in Arctostaphylos . Alaskan tundra Ornithostaphylos Ornithostaphylos is a monotypic genus. It is • Arctous alpina is found circumarctic restricted to northern in tundra, boreal forest and alpine Baja and just crosses into habitats,. S. California. Arctostaphylos Arctostaphylos • One species, A. uva- • Arctostaphylos is the ursi , is found across most diverse genus in the northern the Arbutoideae. hemisphere, in • Life forms range from subalpine, north prostrate plants to temperate forests, and small trees. the California coast. • All are evergreen. • All other species are entirely or partially found in California. A. uva-ursi Arctostaphylos Where do we find manzanitas? • Fossils date back just over 15 MYBP. • Most are relatively recent, less than 1-3 MYBP. • The majority of species are believed to have originated later in the Pleistocene. Elkhorn Slough Coastal Training Program Workshop January 17, 2003 3

The Ecology and Conservation of California's Maritime Chaparral Evolution and distribution of Archtostaphylos Tom Parker Worldwide in the What do these places have in common? Northern Hemisphere • Arctic tundra Nutrient Poor and • Boreal forests Acidic Soils • Subalpine forests • N. Temperate forests • W. N. Am. Mountains • California chaparral Disturbance by Fire • Coastal bluffs, sandy mesas and dunes How do manzanitas How do manzanitas tolerate survive fires? acidic, nutrient poor soils? Manzanitas have a mutualistic relationship with fungi. Together they form mycorrhizal roots. Arctostaphylos sp. Arctostaphylos sp. Arctostaphylos sp. Arctostaphylos sp. Elkhorn Slough Coastal Training Program Workshop January 17, 2003 4

The Ecology and Conservation of California's Maritime Chaparral Evolution and distribution of Archtostaphylos Tom Parker Dicentra Lupinus Phacelia Phacelia Post-fire Annuals are abundant in Chaparral These plants ‘survive’ fire, but reproduce slowly during fire-free periods, buildings populations slowly from seedlings accumulating below chaparral canopies as ‘seedling banks’. Prunus Quercus Rhus Quercus Malosma Most shrubs are obligate sprouters. Species are of two types Arctostaphylos , Ceanothus , and Adenostoma species all produce large, persistent, dormant seed reserves in soil called soil seed banks. Arctostaphylos montana Obligate seeders are killed by Ceanothus jepsonii fire and completely depend upon seedlings after fire to reestablish their populations. No Burl Burls and root crowns permit Adenostoma fasciculatum many species (facultative sprouters) to resprout Soil seed banks of these species after fire. They also have are stimulated by fire Burl seedlings establish following to germinate. fire, but usually at much lower rates. Elkhorn Slough Coastal Training Program Workshop January 17, 2003 5

The Ecology and Conservation of California's Maritime Chaparral Evolution and distribution of Archtostaphylos Tom Parker Obligate Species Richness in Maritime Chaparral Seeders Adenostoma • High Species Richness for the region • Comparing one site to another, stands have A. montana A. glandulosa similar genera, but different species • The richness in diversity is among sites Facultative Sprouters Arctostaphylos in western North America A. andersonii A. edmundsii is concentrated A. pumila on the central Most coastal species California are narrow endemics coast. Most of these species occur in A. montereyensis maritime chaparral. A. refugioensis A. imbricata Maritime chaparral Richness of Arctostaphylos often includes endemism conifers or forms mosaics with conifer • 18 taxa are found in Monterey County forests. • 10 taxa are found in Santa Cruz County • 24 total different taxa for these two counties Mendocino Pygmy Forests • 8 taxa are in San Mateo Co, increasing the total to 28 different taxa • 20 taxa are in San Luis Obispo Co, adding 12 new taxa, totalling 40 for the 4 central coast counties A. glutinosa habitat,Santa Cruz Mts A. sensitiva/silvicola , S. Cruz Mts. Elkhorn Slough Coastal Training Program Workshop January 17, 2003 6

The Ecology and Conservation of California's Maritime Chaparral Evolution and distribution of Archtostaphylos Tom Parker We tested this model, randomly sampling chaparral stands This association between manzanitas and conifers should associated with 6 randomly chosen coastal conifer species. remind you that they can share mutualistic fungi . Stands with invading trees were assessed. Only EM shrub cover was significant for explaining conifer density or basal area in a linear model test This can facilitate each other’s establishment and dominance. Maritime Chaparral Implications for management • Poor Acidic Soils Too frequent, obligate seeders can not form Fire Regime • Canopy fire adaptations (most obl. seeders) seed banks. Too • Variety of types (mesas and dunes, bluffs, Frequency infrequent, conifers forest edges, poor soil outcrops) can invade many sites. Intensity Off season, wrong • Moderated climate with summer fog Season intensity, too small an • High species endemism area, all of these can Area impact the recovery of • Mycorrhizal mutualists shared with conifers the chaparral stands. Elkhorn Slough Coastal Training Program Workshop January 17, 2003 7