Like other serotinous
(meaning their reproduction is prompted by environmental events) cypress species, many of them endemic to California, the MacNabs depend on wildfires to open their tightly sealed cones and release seeds.
In the Sonoran and Mojave deserts of California at least 22 plant species are serotinous
species, plants retain their seeds within protective woody fruits or cones in the canopy, delaying seed release until triggered by an environmental stimulus (LeMaitre 1985; Midgley and Enright 1999).
These fires allow a new generation to emerge by exposing mineral soil, increasing sunlight proliferation, and melting the resin of the tree's serotinous
cones (Tackle 1961).
Ailment is divided into two types based on starting age; precocious and serotinous
. The precocious type is started at childhood and would undoubtedly have retrieved before the age of twelve.
Species have developed different strategies to survive after fire, whether at the individual level, with a thick insulating bark or the ability to resprout from underground parts, or at the population level, with serotinous
cones or seeds which are resistant to or stimulated by high temperatures.
Because lodgepole pines have adapted to produce "serotinous
" cones that are sealed shut by resin, which melts to release the plant's seeds only in the extreme temperatures brought about by forest fires.
The uneven-aged structures are often considered as a hallmark of non-serotinous jack pine populations (Abrams, 1984; Gauthier et al., 1993a; Conkey et al., 1995; Ganthier et al., 1996; Barton and Grenier, 2008), contrasting with even-aged serotinous
jack pine stands whose seedling recruitment is mainly driven by fires in the upper Great Lakes and Canada (Schoenike, 1962; Ganthier et al., 1993a, 1996).
Light black spruce seeds, disseminated from semi - serotinous
cones throughout These old krummholz may persist for centuries until conditions become more favourable, at which time they may increase radial growth rates and initiate sexual reproduction.
In cross SB91925x ICB-1026, the parent SB91925 was more short-legged and serotinous
and it had also more tillers, longer spike, heavier grains per spike, higher thousand grain weight, as well as better harvest index and grain yield per plant.
The ecosystem has species adapted to >0% disturbance, such as lodgepole pine (Pinus contorta) serotinous
cones that release seeds after fire, and thus complete fire suppression to 0% area burned does not produce a sustainable ecosystem.
Some trees, such as jack pine in the Lake States and Canada and lodgepole pine in much of the west, have developed serotinous
cones, that open and disperse seeds only after exposure to intense heat.