EEMB 103A post midterm 1

Chaparral

Characteristic plant community in the CFP, e3ndemic to the mediterranean areas including Baja CA. Composed of Shrubs with sclerophyllous leaves, chaparral scrubland is a community dominated by shrubs with few trees or herbs. Summer drought inhibits tree growth in chaparral. Lack of herbaceous understudy is likely due to root competition and alelopathy of many chapparal species. Fire prone plant community, species evolved to stand-replacing fires to maintain and reproduce themselved

Chamise

Most common shrub in chaparral in rosaceae family. Has highly flammable resinous leaves.

Toyon - California holy, Christmas Berry

Large shrub in the rosaceae family

Manzanita

In the ericaceae family, with 117 taxa in california, some are highly endangered

Ceanothous

85 taxa, common in chaparral

Scrub Oaks

Common taxa in the chaparral

Chaparral Fires

Fires are frequent due to hot, dry conditions where chaparral is found and the high density of plants, especially species with dry or resinous foliage. A chaparral fire removes leaf litter on top of soil volatilizes allelopathic compounds, and removes all vegetation allowing light to penetrate the ground. Chaparral shrub species have devised two strategies for reproduction in a fire-prone habitat: sprouting and seeding

Sprouters

Sometimes called facultative seeders, most species resprout after a fire and germinate from seeds in the soil seed bank (sexual and vegetative). The entire portion of the above-ground plant is burned, but buds protected underground and in thick woody burls survive to resprout. After a fire—with their root system still intact—sprouting shrub species can quickly reoccupy the site. This is a form of asexual reproudction and the seeds in the soil seed bank also germinate (sexual reproduction)

Obligate Seeder

Adult plants are killed by fire; reproduction relies on seeds in the soil seed bank (sexual reproduction). Fire kills adult plants, while the next generation comes from seeds safely stored in the soul seed bank. Chemical leachates from burned plant material stimulates seeds in the soul seed bank to germinate. In California chaparral, only Arctostaphylos and Ceanothus have obligate seeding species: a sexual reproductive event

Fire followers

Many species of annual and short-lived perennials occupy burned patches; some are obligate fire followers. Herbaceous annual plants that maintain seeds in the soil seed bank, after a fire they are stimulated to germinate. They persist for a few years before the chaparral canopy closes

Geophytes

Perrenials with underground structures like bulbs or tubers, are obligate repsrouters, but also repoduce sexually

Soil seed banks

Many plants in different plant communites rely on seeds in the soil seed bank for reproduction. The quantity and diversity of seed in a soil seed bank is dynamic over time as inputs from parents vary year to year. Herbivores and pathogens remove seeds from the soil seed bank. Species that rely on soil seed banks produce seeds with a durable seed coat that persist for decades in the soul. Seeds have chemical and physical cues for germination.