Barberry, Nevin's

Berberis nevinii

division: Magnoliophyta

class: Magnoliopsida

order: Ranunculales

family: Berberidaceae

status: Endangered, ESA

range: USA (California)

Description and biology

Nevin's barberry is a large evergreen shrub with blue- green, spiny leaves, bright red edible berries, and bright yellow flowers that bloom March through April. It is a rhizomatous plant (pronounced RYE-zoe-mat-us; a plant having an underground horizontal stem that puts out shoots above ground and roots below) that measures from 3 to 12 feet (1 to 4 meters) in height. The leaves are pinnate, meaning they are arranged on opposite sides of the stem like feathers. The flowers are clustered, with six petals in two rows. The tiny, juicy berries are about 0.3 inches (6 to 8 millimeters) long.

Habitat and current distribution

Nevin's barberry is found in sandy or gravelly areas or in washes at altitudes ranging between 900 and 2,000 feet (300 and 650 meters) in chaparral habitats of the interior foothill region of southern California. The two largest populations of Nevin's barberry, together containing about 200 individual plants, are found near Vail Lake in southwestern Riverside County. Another large population occurs in San Francisquito Canyon in the Angeles National Forest in Los Angeles County. Beyond these three populations, there are some isolated populations in San Bernardino and Los Angeles Counties. Estimates of the total population place it at around 500 individual plants. Most of the Nevin's barberry habitat lies on private lands in the Vail Lake area, but some populations are located within lands belonging to the Bureau of Land Management, the Cleveland National Forest, and Angeles National Forest.

DID YOU KNOW?

California chaparral is an ecological plant community made up of a variety of scruffy shrubs and bushes, most less than ten feet (3 meters) tall, that are adapted to the dry summers of southern California. Some chaparral plants are: Manzanita, California lilac, Chamise, and Christmas holly. These plants have stiff, shiny leaves with a waxy covering that seals the moisture into the plants so they can survive the dry summer months. Chaparral bushes grow close to each other, forming large thickets across the slopes of hills.

As chaparral communities age, more and more dry wood and leaves build up on the ground under the brush and the area becomes particularly prone to fires. When a fire starts in chaparral country due to lightening or human carelessness, it will spread very quickly. The waxy substance that covers the leaves actually makes the fire burn hotter, and the older the chaparral thicket is when a fire starts, the more the fire will burn. Fires will tear across chaparral-covered hills, leaving a charred desert-like environment behind them. This is actually good for the chaparral. Chaparral seedlings exist in a dormant (not active) state, sometimes for many years, and they are fireproof. When the fire burns off the older chaparral, it also burns off the protective coating of the seedlings in the ground. At the next rain, the seedlings will begin to sprout. (Some varieties of chaparral sprout from underground root systems that don't burn entirely in the fire.) Thus the fire both activates the seedlings and makes way for their growth, which would otherwise be crowded out by the older plants. The area is then repopulated with healthy young plants.

Conservationists (people who work to preserve the natural world) have realized over the years that fires serve a useful purpose in the life cycles of nature. But it is difficult for scientists to plan the frequency or strength of the fires. If there are too many fires in a chaparral area, the young plants may not have time to produce seedlings, and therefore the area will not repopulate. Too much fire prevention can eventually result in fires so hot they could destroy the seedlings or roots.

History and conservation measures

The range of Nevin's barberry has always been limited to specific areas of southern California, and scientists believe it has always consisted of fewer than 30 scattered populations. At least seven former populations have become extinct. The biggest threat to these plants is urbanization, or the building of commercial and residential developments, within their small and specific range. The species requires certain kinds of soil, rock, and moisture, and a chaparral community of plants, to survive. It has been estimated that about 90 percent of the required habitat for this species has been eliminated by urban development, which includes building construction, road construction, flood control systems, and recreational activities, such as the use of off-road vehicles. Southwestern Riverside County developed at a very rapid pace and the Vail Lake area itself became a developing community in the 1990s. Landowners whose property contains Nevin's barberry populations are likely to put in gardens and lawns, which will fragment the surviving populations and introduce nonnative plants to their habitat. The necessary fire management in areas developed for human residence and commerce is not like the natural fire cycles for which chaparral communities are adapted. There are no national recovery plans in place for the species, although research continues.