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.

North Coast Coniferous Forest

A type of pacific temperate rain forest that occurs in the pacific northwest. The forests in California occur in drier areas than further north. The summer drought is moderated by costal flog in the summer. It occurs on terraces and lower slopes of the coast ranges and klamath mountains. Near the immediate coast, it forms a mosaic of plant communities with costal prairies, costal scrub, redwood forests, and closed one coniferous forests. Has grand fir, sitka spruce, and
Western redcedar

Grand Fir (pinaceae)

Likely the tallest species of fir and is highly valued for its wood.

Sitka Spruce (pinaceae)

Can grow 330ft tall, the fifth-largest conifer in the world

Western Redcedar (cupressaceae)

Grows to 230ft tall and can live > 1,000 years

Redwood Forest

In cooler coastal areas, forms a uniform plant community. It’s distribution is limited due to foggy areas. As a dominant species it heavily shapes the environment in the understory, shade, large, shallow roots, thick layer of leaves. Combination of shade, root competition, and deep acidic organic layer inhibits many other species. Ecological disturbances include fire and floods, winter floods deposit silt which the redwoods can tolerate but it smothers other competitors. Massive thick bark is resistant to low or medium intensity fires, eliminating competitors.

Redwood Forest: Fires

Fire is required to recruit redwood seedlings, it removes a thick layer of accumulated leaf litter and understory plants. In areas where fire has been suppressed, tan oak, bay, ample, and mandrone begin to dominate the understory. These hardwood species increase the fire intensity that can kill redwoods.

Redwood Forest: Logging

Redwoods readily stump-sprout after being cut, therefore the forest regenerates but the forest structure is altered. Only 5% of redwood forest is old growth

Freshwater Marsh

Characterized by areas of standing or slow-moving water, can be broadly defined as most any type of perennially wet area, such as margins of lakes, creeks, or sloughs or deltas. The Great Central Valley once has extensive freshwater marshes, but much of those have been drained and converted to farmland. Flora is dominated by monocots, most freshwater marsh species quickly propagate vegetatively to maintain a competitive advantage.

Fabaceae

Legume, pea, or bean family it includes trees, shrubs, and perennial or annual herbaceous plants. They are a large and economically important family that are easily recognized by their fruit (legume) and their compound, stipulate leaves.

Fabaceae subfamily cercidoideae

Leaves are unifoliolate and often bilobed, the flowers are slightly to strongly bilaterally symmetrical. There are generally five free petals, usually 10 stamens in two whorls of alternate length, the fruits are dehiscent, often explosive.

Fabaceae subfamily papilionoideae

Most species we see in CA belong to this subfamily, the flowers likely evolved for bee pollination. The corolla is bilaterally symmetrical, with 5 petals, 1 standard, 2 wings, and 2 keel petals. There are usually 9 stamens fused at the base, forming a tube around the pistil with 1 free stamen.

Valley Grassland

Formerly occupied the great central valley it is characterized by an herbaceous flora, especially perennial grasses. Annual grasslands are more flamable than perennial grasslands, which has impacted many different plant communities. Dead, dry annual grasses carry a fire into adjacent vegetation

Vernal Pools

Pools underlain by clay or hardpan that occur in poorly-drained depressions in a grassland. The pools fill with water in the winder and slowly drain/evaporate through the summer—a difficult environment. It is usually found in mediterranean areas and there are many endemic species of plants adapted to this type of freshwater wetland. There are no fish to serve as predators so there is a variety of amphibians and endemic invertebrates. They are an endangered community in California and almost all vernal pools species are annuals. Recent formation has led to evolution of many neoendemic species. Cyclic ecological succession in a vernal pool is an annual regime, the disturbance is flooding followed by drying of the souls, both plants and animals surivive the dry period in dormant stages

Riparian Woodland

Corridor of, usually deciduous, trees along a creek or river. This type of forest can have a dense understory of shrubs and vines. On steep slopes, the riparian corridor is narrow but spills out onto a valley, broadining considerbly. Riparian zones easily seen on steep mountains or along waterways in large valleys. The primary ecological disturbance is flooding, many riparian trees can withstand inundation of their roots during winter months. The large floods can rip trees from the banks, then deposit new sediments that can be colonized by riparian trees

Mixed Evergreen Forest

Extends from south Oregon to southern California, contains a mix of gymnosperms and hardwoods. Common species include douglas-fir, and pacific madrone (eircaceae), California bay, Black oak, Tanbark oak,

Oak woodlands

Occurs in the coast range valleys and western foothills of the sierra nevada. Covers 10% of California, scattered trees and an herbaceous layer. Sometimes called oak savannah

Coast live oak woodland

Fragments on UCSB campus, dominated by coast live oak

Valley Oak Woodland

Dominated by valley oak, santa ynez valley in sb county

Blue oak-gray pine woodland

Dominated by blue oak and gray pine

Oregon oak woodland

Engelmann oak woodland

Vegetation in montane and transmontane california

Montane plant communities and the habits east of the sierra-cascade axis. Several of these plant communities occur in the desert and great basin floristic provinces. In the desert mountain of socal the montane plant communities are similars to those in the sierra nevada

Montane

Inhabititing mountainous terrain

Lower montane

Ponderosa pine (pinaceae), Incense-cedar (cupressaceae), White fir (pinaceae), Douglas-fir (pinaceae), Sugar pine (pinaceae), Sierra big tree (cupressaceae), Black and canyon oak (in wetter sites they are an important component of the montane forest)

Lower montane forest: Fire ecology

Prior to fire suppression in the mountain west, lighting-cause fire and burning by native americans kept understory relatively opnen. Management improved habitat for grazing wildlife (better hunting) and promoted growth of useful edible plants. Ecological managment and controlled burns can help restore the sierran forests to a more open and less-flammable type. However with years of drought and more fire frequency, many confier species now susceptible to die-off, creating vast areas of highly flammable forest.

Poaceae

Important family ecologically and economically. In california, grasses occur in every plant community. They are annual or perennial herbs, stems of grasses are usually called culms, usually cylindrical and hollow except at nodes, leaves are usually alternate and distichous (in one plane). Each leaf is differentiated into a sheath wrapping around the stem and a blade or lamina, the base of the blade often wraps around the culm forming an auricle. Flowers, or florets, arranged into spikelets, with each spikelet having one or more florets. The spikelets are grouped into panicle sor spikes.

Ligule

Membranous or ciliate collar at the junction of the blade and sheath

Ranchilla

Spikelet axis

Spikelet

Consists of two bracts at the base, called glumes

Floret

Consists of the flower surrounded by two bracts, one external (the lemma) and one internal (the palea)

Juncaceae

The rush family, usually slow-growing, rhizomatous, herbaceous monocots, typically grow in cold or wet habitats; most common in montane environments. Often perennial species ressembling grasses, flowers are arranged in terminal or lateral inflorescence of loose cymes or dense heads. The family typically has reduced perianth segments called tepals; arranged in two whorls. each containing three thin, papery tepals. color varies from greenish to whitish, brown, purple, black, or membranous. There are three stigmas and the fruit is usually a three-parted capsule containing many seed

Cyperaceae

Grass-like herbaceous plants compromising 70 genera, commonly found in wet or saturated conditions. The stems are usually 3-angled and solid, the leaves are alternate, usually with a closed sheathing base and a parallel veined, strap-shaped blade. Each floret is in the axial of a bract, and these are arranged spirally or distichously in spikelets. The perianth may be represented by scales or bristles in two whorls, but is usually lacking. The androecium consists usually of 3 distinct stamens. The gynoecium consists of a single compound pistil of usually 2 or 3 carpels, a signle style usually with 2 or 3 lobes or branches, and a superior ovary with a single locule containing a single basal ovule. In carex, the ovary is enveloped by a membranous sac called a perigynium, the fruit is a 3-angled or lens-shaped achene

Cyperaceae: Carex

Flowers usually unisexual, can be difficult to ID, the perigynium is a defining character; a bottle-shaped bract that surrounds the female flower.

Asteraceae

Second largest family in the world (after orchidaceae), aster or sunflower composite family. In CA most are herbaceous annual or perennials and shrubs. Have evolutionary advanced inflorescences called heads, or capitula, heads resemble a single flower to attract pollinators

Asteraceae characteristics

Most heads have phyllaries, a type of bract, subtending the inflorescence, sometimes, especially if the phyllaries are fused, they are collectively called the involucre. The flowers usually have 5 stamens, the filaments are fused to the base of the corolla, and the anthers are generally fused to form a tube around the style. The ovary is inferior and has only one ovule with basal placentation, the style has two lobes. Have pappus

Pappus

An aggregate of hair-like structures such as awns, bristles, or scales arising from the top of the inferior ovary in place of the calyx

Ligulate head

Composed of ligulate flowers, a bisexually, bilaterally symmetrical flower. The outer portion of the ligule (corolla) is strap or fan-shaped with 5 lobes. there are no paleae (receptacle bracts subtending flowers)

Discoid Head

Composed of disc flowers, a bisexual flower with a radially symmetrical, fused corolla with 5 lobes. Disk flowers often have a palea, a scale inserted on the receptacle and subtending an individual flower, also called chaff scales this is a major character used in keys.

Disciform head

Similar to a discoid head, but marginal flowers are pistillate or sterile with missing or reduced corolla, resembles a superficially discoid head.

Radiant head

Similar to discoid head but marginal flowers have much enlarged, bilaterally symmetrical corollas

Radiate Head

Composed of ray and disk flowers. Ray flowers are pistillate or sterile flowers and the corolla is 3-lobed. The flowers appear as a ring around a central cluster of disk flowers, and disk and ligulate flowers have a 5-lobed corolla.

California Coastal Prairie

Costal prairie occurs sporadically along the coast of california, located immediately inland from the costal strand. The floristic components are a mix of grasses, annuals, and herbaceous perennials, trees and shrubs are absent. Occurs on costal marine terraces, costal bluffs, hillsides, and costal bald hills. Has been heavily impacted by cattle grazing, less than 1% remains, originally dominated by herbaceous flowering plants and grasses, invasive species have replaced most of native flora. Support the highest plant diversity of any grassland in the US.

California Coastal Prairie ecology

Regarded as a climax vegetation, like other types of grasslands, they are sustained by disturbances that prevent invasion by shrubs and trees. Indigenous Californians regularly burned costal grasslands to increase the quality and quantity of grassland resources for their use. Through burning practices, extent of costal prairies likely increased relative to adjacent habitats. Trees and shrubs are encroaching on unburned prairie

Costal Salt Marsh

Found in estuaries and bays that are subject to tidal influence, the distribution of species is determined by the duration of tidal flooding. They are inundated with salt water by tidal cycled (daily disturbance) and the soils found here are usually fine silty-clay. The soil is wet, low in oxygen content, and salty which is an extreme environment for plants. All plants growing in salt marshes are halophytes with a variety of adaptations.

Salt tolerance adaptations in the salt marsh

Osmotic adjustment, salt exclusion, salt excretion, compartmentalization

Osmotic adjustment

Plants can adjust their internal osmotic pressure to match the high salinity of the surrounding environment.

Salt exclusion

Some plants have specialized roots that prevent salt from entering the plant’s vascular system

Salt excretion

Some species have salt glands that excrete excess salt through the leaves or other tissues

Compartmentalization

Salt ions may be localized in vacuoles to minimize their impact on other cellular processes

Other adaptations to life in the salt marsh

To conserve water they have succulent leaves/a thick waxy layer on leaves. For oxygen they have aerenchyma tissue

Salt Marsh: diversity

The diversity in salt marshes is relatively small because so few species have adapted to the difficult conditions. Some inland salt flats in the desert have related species from the same salt marsh genera. Migratory and shorebirds present; marine nurseries for fish and invertebrates

Case study: china camp state park

Costal sage scrub

Often divided into two or more subtypes, species composition varies from north to south, often called “soft chaparral”, highly endangered plant community in California. Shrubland plant community dominated by subwoody species with areas of herbaceous understory. Occurs primarily in the dry foggy costal zone and a little furger inland. Many constituent species are aromatic (to deter herbivory)

Northern costal sage scrub

From slo countu north to southern oregon, dominated by evergreen shrubs (more rainfall). There is a dynamic interaction between northern costal sage scrub and costal prairie. Several species in NCSS also occur in adjacent communities like prairies of forests.

Southern costal sage scrub

From slo county south to baja CA, high percentage of deciduous species (drought decidous), reaches much further inland than NCSS. Further south, succulents such as cactuses and dudleyas increase. Also integrades with other plant communites, often forms a mosaic on the landscape with chaparral, grasslands, costal prairie and other types. Costal sage scrub vegetation becomes dry and brittle by the end of summer drought, fires occur every 20 years. Species regenerate mainly by sprouting from below-ground buds. seeds in the soul seed bank also contribute to regeneration of the plant community.

Closed-cone pine forest

Pine-dominated forests that are fire-dependent. Closed-code species have cones produced each year but the seeds remain sealed in the cone with sap; a serotinous cone. Species with serotinous cones only open after fire or on very hot days. The fire regime in a closed-cone pine forest is stand-replacing; all adult trees are killed and the forest regenerates from seeds released from cones.

Closed-cone pine forest: Bishop pine

Bishop pine dominated forest: from humboldt count tot the nothern channel islands. Trees not exposed to fire after ca. 80 years will begin to succum to diseases such as western gall rust and die without reproducing.

Closed cone pine forest: the pygmy forest of mendocino county

Waterlogged clay soils underlain by a hard-pan prevent roots from penetrating very deeply

Closed-cone pine forest: monterey pine

Pinus radiata has limited natural range in california. It is an ideal soft-wood lumber tree and is the most widely planted forest tree on earth. Range no more than 11k acres (small for forest tree species). Species limited to costal areas with summer fog. Endangered by climate change and pine pitch canker which is caused by a fungal pathogen. Apx 10% of monterey pines are at lease somewhat resistant to pitch canker

Closed cone pine forest: Knobcone pine

Not a dominate species of its own forest type, behaves as a closed-cone pine. Grows in dry, rocy areas, sometimes on serpentine rocks from sea level to 6k ft. Occurs in oregon to Baja, growing in the chaparral makes it susceptible to fire

Upper montane forest

Above lower montane, abt 7k-9k ft. Dominate species include lodgepole pine, california red fr, and western juniper

Lodgepole pine

Not necessarily fire-dependent, but responds positively to fire. An indicator species of the upper montane forest zone. Ectomychorrhizae allow it to colonize poor soils, highly invasive in new zealand.

California Red Fir

Another indicator species of the upper montane forest, shade tolerant

Montane Chaparral

Grows as a mosaic among the montane forests; on rocky substrates with little soil. Slow ecological succession to montane forest. Burns rarely; not fire-dependent like true, low-elevation chaparral. Same genera but different species of true chaparral, most spp. are sprouters. Important species include; white thorn, tobacco brush, huckleberry oak, bitter cherry, and green leleaf manzanita

Subalpine forest

Above the upper montane forest but below the alpine zone. Usually a gradual transition, tree density is too thin to support fire. Dominant species include Hemlock, white bark pine, bristlecone pine

Bristlecone pine

Longest-lived non-clonal organism, methuselah is 4,853 years old and the location is kept a secret by the forest service to protect it.

Montane Meadow

Dominated by herbaceous species such as perennial grasses, sedges, and rushes. Salix are common around the margins or in riparian areas. Best developed in areas where mountain lakes are transitioning to meadows by silt deposition

Alpine fell-field

Above subalpine forest, winter conditions become too cold and windy to support trees. The near-constant wind prevents accumulation of soil. Perennial herb-dominated community (mainly dicots). Growing season too short for many annual species, plants growing there show a variety of adaptations to the wind. Precipitation comes as snow during the winter, growing season < 2 months. Difficult abiotic conditions limit invasive species, little ecological disturbances (aside from landslides, erosion, grazing). Alpine zones across the american west function biogeographically as an island archipelago “sky islands)

Plant communities - transmontane california

Includes plant communities east of sierra cascade axis and the deserts

Piyon-juniper woodland

On eastern slope of sierra cascades and extending into the great basin desert. covers a vast area of the american west, some of these woodlands to the the north of SB. Forms mosaic with sage scrub. Threatened by invasive annual grasses, especially bromus tectorum or cheat grass. The grass is stimulated by fire, after each fire it expands its range and the dead grass carries the fire into the sage scrub and pinyon-juniper woodland.

Sagebrush Scrub

Shrubland community occupying vast areas in the western US, sometimes called “sage steppe”. Forms a mosaic with pinyon-juniper woodland. Causes and feedbacks to widespread grass invasion into chaparral shrub dominated landscapes (look at diagram). Dominated by artemisia tridentata, leaves have three teeth at the apex. Occurs in the great basin and adjacent areas, often called the “intermountain west”, climate is semi-arid to arid cold winters and hot summers.

Sagebrush scrub - Fire

Prior to Europe/american settlement, fires regularly burned the sagebrush scrub. Ignited by frequent lightning and native americans but long term impacts not well understood by ecologists. Interval and intensity of fire varied over the landscape due to variation in topography, soil, vegetation, fuels, moisture, other disturbance history , etc. Fire frequency is difficult to estimate bc sagebrush scrub species do not record fire scars. Est. range from 25 to 80 years , artemisia tridentata is killed by fire. Post-fire establishment is dependent on recruitment of seeds dispersing to the fire scar. There is a soil seed bank but it is not as robust as that of the chaparral. Type converstion to grassland or woodland is common

Sagebrush scrub - changes in grazing

7k years ago, bison, elk, moose, deer, etc grazed in sagebrush, american settlers introduced cattle. Overgrazing resulting in the spread of invasive species, effects of the mechanical conversion in the 50s and 60s to crested wheatgrass have persisted.

Sagebrush scrub - woodland expansion

Since american settlement, juinpers and pinyon pines have increased density in sagebrush scrub, reasons are not clear, perhaps long-term climate patterns or decreased fire frequency. Manual removal of junipers increases value to wildlife.

Sagebrush scrub - invasive grasses

cheatgrass has had a huge impact on the structure of sagebrush scrub. Cheatgrass is highly resillient to fire; it can occupy burned sites from adjacent seed sources, a major source of fuel to carry fire in the great basin.