How do pine trees remove pollen? I've heard that the tree actually shakes itself; is this true?

Pollen in pinus are produced in the Male cone made up of a large number of microsporangia.





kindly click on the link below to see male cones-





http://en.wikipedia.org/wiki/Image:Pinef...





Each microsporangium has pollen sacs in which pollen is produced.





In the link below there are a few pollen sac and each one is full of pollen.


http://www.lima.ohio-state.edu/academics...





Each pollen grain has two wings with the help of which they ride the wind and reach female cone.





The links below shows pinus pollen with wings.


http://www.byteland.org/naturalist/galle...


http://www.botany.hawaii.edu/faculty/web...





The natural colour of the pollen is yellow and when they are released in the air in massive quantity the air is charged with yellow pollen like in a dust storm the air is charged with dust particles.





Pinus tree DOES NOT shake it self to release pollen like a wet dog shakes itself to get dry. There is no explosive dehiscence either.


It is just pollen sacs split open silently to release pollen in the prevailing wind.

How do pine trees remove pollen? I've heard that the tree actually shakes itself; is this true?
Pollen is windblown. The wind shakes the tree(s).
Reply:Trees will not shake themselves but the are able to move their leave to get the maximum sun onto them. Most pollen is dispersed by the wind. Pine trees are cone bearing which means that they are usually wind pollenated. Coniferous, a type of evergreen tree developed as a response to extreme weather conditions were strong air currents could blow the pollen many meters. Insects developed when deciduous trees began to produce flowers.
Reply:A few clarifications, and a response:





Pine trees do not have flowers but do have male and female reproductive parts, and thus pollen. It is true that pines are wind-pollinated (no self-respecting insect would waste its time looking for non-existent flowers from which to steal nectar on a pine ;). There is fossil evidence for insects and flowers evolving together. All pines, spruces, firs etc (needle evergreens) lack flowers and are called conifers. Not all flower-bearing trees are deciduous (lose their leaves in the winter). Not all conifers keep their needles in the winter (eg bald cypress).





Pines don't actually shake themselves, but the release of pollen can be explosive--not sure of the mechanism (spring-loaded? ;)--- and noticeable. I have seen this phenomenon, when there was no wind to have caused the pollen to loft visibly. It can happen all at once (an internal physiological trigger at the pollen-bearing site), giving the appearance that the tree is itself shaking off the pollen.