Definitions

Biodiversity Hotspot: A priority region for environmental stewardship because it contains a large number of species (more than 1500) that occur nowhere else and a significant portion of its vegetation is threatened (30% or more).  The California Floristic Province is considered a biodiversity hotspot because of its unique endemic species and the rapid loss of habitat. 1

California Floristic Province: A region comprising most of the state of California recognized as an important and threatened ecological resource hosting endemic species found nowhere else on Earth. California is home to only one of five areas with a Mediterranean-type climate in the world, which is classified by hot, dry summers and cool, wet winters. This richly diverse ecology hosts a variety of ecosystems ranging from redwood forests and chaparral to coastal dunes and salt marshes. Less than a quarter of the original province remains in the world.2

Ecology:  The scientific study of the distribution and abundance of organisms and the interactions among organisms and their environments.

Ecological Corridor:  A Linear zone that creates linkages between habitat patches; corridors can provide critical avenues of movement for species to travel between patches for food, shelter, and reproduction; other types of corridors may serve as barriers to movement, such as highways or other low habitat quality infrastructure.

Ecosystem Services: “The benefits people obtain from ecosystems” (2006 Millennium Ecosystem Assessment). Services have been grouped into four categories: provisioning, the products of an ecosystem (such as food, water, and raw materials); regulating, benefits of ecosystem processes (such as carbon sequestration); supporting, services that allow other ecosystem services to function (such as pollination); and cultural, benefits described as recreational, aesthetic, cognitive and spiritual.

Edge: “The outer portion of the patch where the environment differs significantly from the interior of the patch” (Dramstad, Olson + Forman); transition zone between two types of habitat, often referred to as an ecotone.

Endemic: A species is defined as endemic if it occurs in a specific geography or is associated exclusively with a particular habitat type and is found nowhere else.

Matrix: The “background ecological system of a landscape” within which patches and corridors are located.3

Mosaic: The pattern and scale of patches, corridors, and matrix that make up a landscape

Mediterranean Biome: a climate region characterized by cool wet winters and hot dry summers; includes mediterranean forest, woodland, savannah, and scrub plant communities.  The biome is a conservation priority because while the region only represents 2% of the Earth’s surface it supports 20% of the Earth’s vascular plant species.4

Patch: A relatively homogeneous area that differs from its surroundings; analysis of size, number, location, and quality relative to adjacent conditions can determine what types of species and populations a patch can support.

Significant Ecological Areas: The delineation of Significant Ecological Area (SEA) is a program of Los Angeles County that identifies areas with the existence of important biological resources that should be considered when planning for development or preservation. The Santa Monica Mountains, Verdugo Mountains, and Griffith Park are three SEAs disconnected from but in close proximity to the LA River.  Resident and migratory birds to move between the River corridor and the SEAs.


1 Conservation International, http://www.conservation.org/How/Pages/Hotspots.aspx (2016)
2 Critical Ecosystem Partnership Fund. Conservation International (2015).
3 Forman, R.T.T., Land Mosaics: The Ecology of Landscapes and Regions. Cambridge University Press, Cambridge, UK (1995)
4 Klausmeyer and Shaw, William Hunter, III ED.,Recent Advances in Environmental Science, Mediterranean Ecosystems Worldwide: Climate Adaptation (2011)