Closed-cone pine forest

Closed-cone pine forest is a plant community of coastal California and several offshore islands. The plant community is often mono-dominant and single-aged, but dense with ladders. Closed Cone forests grow in low nutrient and/or stressed soils, which can lead to slow growth. It consists of stands of bishop pines, Monterey pines, and others which rely on fire and shoot death to open their cones and release the seeds.

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 in the north to the northwestern corner of Baja California in the south. knobcone pine (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

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 regions along the coast with cool wet winters and foggy, 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.

The conifers are serotinous, meaning they release seeds in response to an environmental trigger. Seed release in the forest relies on fire and 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. Although shoot death can be cause 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. Serotiny offers benefits to plant species because after a fire, there is less competition for the seeds on the ground. Thus, the fire signals an advantageous time for trees to drop their seeds.

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