Chaparral is a shrubland plant community found primarily in California, in southern Oregon and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean climate and infrequent, high-intensity crown fires. Chaparral are typically embedded with hard sclerophyllous evergreen leaves, as contrasted with the associated soft-leaved, drought-deciduous, scrub community of coastal sage scrub, found often on drier, southern facing slopes within the chaparral biome. Three other closely related chaparral shrubland systems occur in central Arizona, western Texas, and along the eastern side of central Mexico's mountain chains (mexical), all having summer rains in contrast to the Mediterranean climate of other chaparral formations. Chaparral comprises 9% of California's wildland vegetation and contains 20% of its plant species.
Pioneer species are hardy species that are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by wildfire.
Ecological succession is the process of change in the species structure of an ecological community over time. The time scale can be decades or more or less.
The ecology of California can be understood by dividing the state into a number of ecoregions, which contain distinct ecological communities of plants and animals in a contiguous region. The ecoregions of California can be grouped into four major groups: desert ecoregions, Mediterranean ecoregions, forested mountains, and coastal forests.
An old-growth forest, sometimes synonymous with primary forest, virgin forest, late seral forest, primeval forest, or first-growth forest—is a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological features, and might be classified as a climax community. The Food and Agriculture Organization of the United Nations defines primary forests as naturally regenerated forests of native tree species where there are no clearly visible indications of human activity and the ecological processes are not significantly disturbed. More than one-third of the world's forests are primary forests. Old-growth features include diverse tree-related structures that provide diverse wildlife habitat that increases the biodiversity of the forested ecosystem. Virgin or first-growth forests are old-growth forests that have never been logged. The concept of diverse tree structure includes multi-layered canopies and canopy gaps, greatly varying tree heights and diameters, and diverse tree species and classes and sizes of woody debris.
The ecology of the Sierra Nevada, located in the U.S. states of California and Nevada, is diverse and complex. The combination of climate, topography, moisture, and soils influences the distribution of ecological communities across an elevation gradient from 500 to 14,500 feet. Biotic zones range from scrub and chaparral communities at lower elevations, to subalpine forests and alpine meadows at the higher elevations. Particular ecoregions that follow elevation contours are often described as a series of belts that follow the length of the Sierra Nevada. There are many hiking trails, paved and unpaved roads, and vast public lands in the Sierra Nevada for exploring the many different biomes and ecosystems.
Fire ecology is a scientific discipline concerned with natural processes involving fire in an ecosystem and the ecological effects, the interactions between fire and the abiotic and biotic components of an ecosystem, and the role as an ecosystem process. Many ecosystems, particularly prairie, savanna, chaparral and coniferous forests, have evolved with fire as an essential contributor to habitat vitality and renewal. Many plant species in fire-affected environments use fire to germinate, establish, or to reproduce. Wildfire suppression not only endangers these species, but also the animals that depend upon them.
Xerosere is a plant succession that is limited by water availability. It includes the different stages in a xerarch succession. Xerarch succession of ecological communities originated in extremely dry situation such as sand deserts, sand dunes, salt deserts, rock deserts etc. A xerosere may include lithoseres and psammoseres.
A hydrosere is a plant succession which occurs in an area of fresh water such as in oxbow lakes and kettle lakes. In time, an area of open freshwater will naturally dry out, ultimately becoming woodland. During this change, a range of different landtypes such as swamp and marsh will succeed each other.
Coastal sage scrub, also known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is within the California chaparral and woodlands ecoregion, of the Mediterranean forests, woodlands, and scrub biome.
Adenostoma fasciculatum, commonly known as chamise or greasewood, is a flowering plant native to California and Baja California. This shrub is one of the most widespread plants of the California chaparral ecoregion. Chamise produces a specialized lignotuber underground and at the base of the stem, known as a burl, that allow it to resprout after fire has off burned its stems. It is noted for its greasy, resinous foliage, and its status as one of California's most iconic chaparral shrubs.
Henry Allan Gleason (1882–1975) was an American ecologist, botanist, and taxonomist. He was known for his endorsement of the individualistic or open community concept of ecological succession, and his opposition to Frederic Clements's concept of the climax state of an ecosystem. His ideas were largely dismissed during his working life, leading him to move into plant taxonomy, but found favour late in the twentieth century.
Prunus ilicifolia is native to the chaparral areas of coastal California, Baja California, and Baja California Sur. as well as the desert chaparral areas of the Mojave desert.
Old field is a term used in ecology to describe lands formerly cultivated or grazed but later abandoned. The dominant flora include perennial grasses, heaths and herbaceous plants. Old fields are canonically defined as an intermediate stage found in ecological succession in an ecosystem advancing towards its climax community, a concept which has been debated by contemporary ecologists for some time.
A beech–maple forest or a maple beech forest is a climax mesic closed canopy hardwood forest. It is primarily composed of American beech and sugar maple trees which co-dominate the forest and which are the pinnacle of plant succession in their range. A form of this forest was the most common forest type in the Northeastern United States when it was settled by Europeans and remains widespread but scattered today.
A fire regime is the pattern, frequency, and intensity of the bushfires and wildfires that prevail in an area over long periods of time. It is an integral part of fire ecology, and renewal for certain types of ecosystems. A fire regime describes the spatial and temporal patterns and ecosystem impacts of fire on the landscape, and provides an integrative approach to identifying the impacts of fire at an ecosystem or landscape level. If fires are too frequent, plants may be killed before they have matured, or before they have set sufficient seed to ensure population recovery. If fires are too infrequent, plants may mature, senesce, and die without ever releasing their seed.
Climax species, also called late seral, late-successional, K-selected or equilibrium species, are plant species that can germinate and grow with limited resources; e.g., they need heat exposure or low water availability. They are the species within forest succession that are more adapted to stable and predictable environments, and will remain essentially unchanged in terms of species composition for as long as a site remains undisturbed.
Chrysolepis chrysophylla is a species of flowering shrub or tree in the beech family known by the common names golden chinquapin, giant chinquapin, and western chinquapin. It is native to the Pacific coast of the United States.
Ponderosa pine forest is a plant association and plant community dominated by ponderosa pine and found in western North America. It is found from the Rocky Mountains to the Pacific Coast Ranges in the Western United States and Western Canada. In the south and east, ponderosa pine forest is the climax forest, while in the more northern part of its range, it can transition to Douglas-fir or grand fir, or white fir forests. Understory species depends on location. Fire suppression has led to insect outbreaks in ponderosa pine forests.
Biogeoclimatic ecosystem classification (BEC) is an ecological classification framework used in British Columbia to define, describe, and map ecosystem-based units at various scales, from broad, ecologically-based climatic regions down to local ecosystems or sites. BEC is termed an ecosystem classification as the approach integrates site, soil, and vegetation characteristics to develop and characterize all units. BEC has a strong application focus and guides to classification and management of forests, grasslands and wetlands are available for much of the province to aid in identification of the ecosystem units.
