Young Swedish Blonde Girl By The Pine Tree

Pines are mostly monoecious, having the male and female cones on the same tree, though a few species are sub-dioecious with individuals predominantly, but not wholly, single-sex. The male cones are small, typically 1–5 cm long, and only present for a short period (usually in spring, though autumn in a few pines), falling as soon as they have shed their pollen. The female cones take 1.5–3 years (depending on species) to mature after pollination, with actual fertilization delayed one year. At maturity the female cones are 3–60 cm long. Each cone has numerous spirally arranged scales, with two seeds on each fertile scale; the scales at the base and tip of the cone are small and sterile, without seeds. The seeds are mostly small and winged, and are anemophilous (wind-dispersed), but some are larger and have only a vestigial wing, and are bird-dispersed. At maturity, the cones usually open to release the seeds, but in some of the bird-dispersed species (e.g. Whitebark Pine), the seeds are only released by the bird breaking the cones open. In others, the fire climax pines (e.g. Monterey Pine, Pond Pine), the seeds are stored in closed ("serotinous") cones for many years until a forest fire kills the parent tree; the cones are also opened by the heat and the stored seeds are then released in huge numbers to re-populate the burnt ground.
Ecology
Pines grow well in acid soils, some also on calcareous soils; most require good soil drainage, preferring sandy soils, but a few (e.g. Lodgepole Pine) will tolerate poorly drained wet soils. A few are able to sprout after forest fires (e.g. Canary Island Pine). Some species of pines (e.g. Bishop Pine) need fire to regenerate, and their populations slowly decline under fire suppression regimes. Several species are adapted to extreme conditions imposed by elevation and latitude (e.g. Siberian Dwarf Pine, Mountain Pine, Whitebark Pine and the bristlecone pines). The pinyon pines and a number of others, notably Turkish Pine and Gray Pine, are particularly well adapted to growth in hot, dry semi-desert climates.