Closed-cone pine forest is a plant community of coastal

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

and several offshore islands. The plant community is often mono-dominant and single-aged, but dense with ladder fuels. Closed Cone forests grow in low nutrient and/or stressed soils, which can lead to slow growth. It consists of stands of coniferous species which rely on fire or shoot death to open their cones and release the seeds. Examples of species include coulter pine, monterey pine, and bishop pine.

Closed-cone pines

The most widespread naturally of the closed-cone pines is bishop pine (''Pinus muricata''), which can be found along the coast from

Humboldt County, California Humboldt County () is a county located in the U.S. state of California. As of the 2020 census, the population was 136,463. The county seat is Eureka. Humboldt County comprises the Eureka–Arcata–Fortuna, California Micropolitan Statistica ...

in the north to the northwestern corner of

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in the south.

Knobcone pine The knobcone pine, ''Pinus attenuata'' (also called ''Pinus tuberculata''), is a tree that grows in mild climates on poor soils. It ranges from the mountains of southern Oregon to Baja California with the greatest concentration in northern Calif ...

(''Pinus attenuata'') forests can occur further inland, on dry, rocky soils. Monterey pine (''Pinus radiata'') was once limited to the Monterey Peninsula, two other sites in central California, and Guadalupe and Cedros Islands off the coast of Baja California, but has now been introduced elsewhere in California and around the world. Most of these trees have an average life-span of around 50–90 years

Climate

The weather of these forests is quite mild in both winter and summer. Temperatures rarely go below freezing or grow uncomfortably warm. Closed-cone pine forests of California are located in cool-summer

Mediterranean climate A Mediterranean climate (also called a dry summer temperate climate ''Cs'') is a temperate climate sub-type, generally characterized by warm, dry summers and mild, fairly wet winters; these weather conditions are typically experienced in the ...

regions along the coast with cool wet winters and hot, dry summers. Despite the fact that the summers are dry, the air is consistently humid due to frequent coastal fog brought in by interior heat. The fog also supplies irrigation when it passes through the conifer needles of the pines. The moisture is caught this way and drips to the forest floor. Thus, drought is avoided by up to 40%. In the autumn, fog is less frequent and it is during this season when occasional heat waves are possible. This is when fires are most likely. Precipitation ranges from 20 to 60 inches a year, depending on the locale.

Environmental Triggers

The conifers are serotinous, meaning they release seeds in response to an environmental trigger, such as fire or shoot death. Shoot death is when death of a stem signals cones to release seeds. One example of serotiny due to shoot death is cupressaceae (pinacaea refers to seritony from fire/heat). Although shoot death can be caused by fire, there are other sources of stem death. Closed-cone forests rely on predictable, infrequent fires. The fires are stand-replacing crown fires. One example of serotiny due to fire is Pinacae releasing seed after the cone has undergone 200°C for five minutes. Sargent cypress, Gowan cypress, McNabb cypress, Monterrey Pine, and Torrey Pine are all California endemic serotinous conifer species. Other serotinous conifer species that are not CA endemic include bishop pine, coulter pine, knob-cone pine, and lodgepole pine. Serotiny offers benefits to plant species because after a fire, there is less competition for the seeds on the ground; fire also opens up either space in the canopy or clears away litter on the ground. Thus, the fire signals an advantageous time for trees to drop their seeds.

Other flora and fauna

While the pines are, by far, the most common tree in these forests, coast live oaks often accompany them. Due to the relatively short lifespan of closed-cone pines, many dead trunks and snags are available and attract a whole host of wildlife ranging from woodpeckers,

titmice ''Baeolophus'' is a genus of birds in the family Paridae. Its members are commonly known as titmice. All the species are native to North America. In the past, most authorities retained ''Baeolophus'' as a subgenus within the genus ''Parus'', bu ...

, chickadees, warblers, squirrels, chipmunks, raccoons,

mountain lions The cougar (''Puma concolor'') is a large cat native to the Americas. Its range spans from the Canadian Yukon to the southern Andes in South America and is the most widespread of any large wild terrestrial mammal in the Western Hemisphere. I ...

deer Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...

and many others. The lush undergrowths, typical of the forests, are excellent habitat as well. Blackberries, wild roses, wood mints, California honeysuckle, currants, and others are common. The flora and fauna varies from area to areas, especially the southern and northern closed-cone pine regions. Soils have low nutrients and are stressed due to a lack of nitrogen. This promotes slow growth.

References

California’s Changing Landscapes, by Barbour et al. Ch.3 (1997, California Native Plant Society)

External links