fire can cause several effects on the soil, such as increasing the temperatures of the soil during the day due to increased solar radiation on the soil surface, and greater cooling due to loss of radiative heat at night. Fewer leaves to intercept rain will also cause more rain to reach the soil surface, and with fewer plants to absorb the water, the amount of water content in the soils might increase. However, it might be seen that ash can be water repellent when dry, and therefore water content and availability might not actually increase. Biotic responses and adaptations Plants Plants have evolved many adaptations to cope with fire. Of these adaptations, one of the best-known is likely pyriscence, where maturation and release of seeds is triggered, in whole or in part, by fire or smoke; this behaviour is often erroneously called serotiny, although this term truly denotes the much broader category of seed release activated by any stimulus. All pyriscent plants are serotinous, but not all serotinous plants are pyriscent (some are necriscent, hygriscent, xeriscent, soliscent, or some combination thereof). On the other hand, germination of seed activated by trigger is not to be confused with pyriscence; it is known as physiological dormancy. In chaparral communities in Southern California, for example, some plants have leaves coated in flammable oils that encourage an intense fire. This heat causes their fire-activated seeds to germinate (an example of dormancy) and the young plants can then capitalize on the lack of competition in a burnt landscape. Other plants have smoke-activated seeds, or fire-activated buds. The cones of the Lodgepole pine (Pinus contorta) are, conversely, pyriscent: they are sealed with a resin that a fire melts away, releasing the seeds. Many plant species, including the shade-intolerant giant sequoia (Sequoiadendron giganteum), require fire to make gaps in the vegetation canopy that will let in light, allowing their seedlings to compete with the more shade-tolerant seedlings of other species, and so establish themselves. Because their stationary nature precludes any fire avoidance, plant species may only be fire-intolerant, fire-tolerant or fire-resistant. Fire intolerance Fire-intolerant plant species tend to be highly flammable and are destroyed completely by fire. Some of these plants and their seeds may simply fade from the community after a fire and not return; others have adapted to ensure that their offspring survives into the next generation. "Obligate seeders" are plants with large, fire-activated seed