Pine :- General Introduction
Pine is any conifer in genus Pinus. The genus Pinus if of great ecological and commercial importance. It is very large genus with almost 126 species. Some othe tree genera contain even more species, but Pinus stands out on account of its geographical range and other characteristics.
The modern English name pine derives from Latin pinus, which some have traced to the Indo-European base pīt- ‘resin’ (source of English pituitary). Before the 19th century, pines were often referred to as firs (from Old Norse fura, by way of Middle English firre).
Family:- Pinaaceae, which in turn is the largest family with in the coniferales.
Pines are the gymnosperms
The Pine or Pinus having two main subdivision
- Diploxylon (hard Species): The Diploxylon includes species with 2, 3 or 5 needles per fascicles.
- Haploxylon (Soft Species): In Haploxylon all species contains the almost 5 needles. In Haploxylon cones are generally soft and elongated. Presence of single vascular bundles in needles.
The distinguishing features of pines are combination of cone characteristics (bract scales and ovuliferous scales becoming closely fused during cone development) and the secondary foliage comprising grouping of two, three or five needles into short shoots called fascicles, with sheaths of soft scales at the bases (Exceptions: P. monophylla, P. krempfii).
Branches are occurs in discrete clusters. Some species are monocyclic and some are polycyclic. Monocyclic produce only one cluster of branches on the bole per years, and polycyclic produce more than one cluster on bole per year.
All the species are evergreen, although the longevity of foliage can range from under 2 years to well over 5 years.
Pine: Evolutionary History
Pinus or pine is quite an ancient genus. It is now thought to have evolved in the early-middle Mesozoic era, in the region that has now split, through plate tectonic movements, into eastern North America and western Europe.
Pine: General Ecology
- Site Requirement:
- Fire Ecology
- Human Impacts
Site requirement: Pines of different species grow in a very wide range of climate range from rainforest to grassland steppe. Pines can survive in some high mountain areas with low precipitation. In the northern hemisphere latitudinal range is extremely high which range from the equator to arctic circle.
Pines are generally found on medium to low fertility Ssoil, but species still vary widely in their edaphic requirements. Symboic association in pines are very important because these association helps to grow pines in infertile soils. If Pines are grown in very highly fertile soils this very degrade the wood quality or wooden properties of the pine (except P. elliotti and P. contorta).
Their are many strategies whereby different pine species are ecologically adapted to fires. Most pine species depend in some measure on fire for maintaining their ecological status. Fires are important for killing the weeds which competing the woody plants and retard their growth in some cases. A Few pine species have a very different mechanism of fire resistance, which is more typical of certain hardwoods. this is based on an ability to resprout from the stem or lower bole after crown are killed by fire (P. canariensis, P. oocarpa and p. rigida).
Human impacts have been widespread and varied Many pine specie have been subject to largely uncontrolled exploitation. Clearig forest for agriculture has reduced many natural stands but sometimes only temporarily. Other indirect human impact is through introduction of browsing animals.
Pine : Uses
- Wood: easy to use, as wawn timber, various panel productss, round produce, and pulp for paper and board products. Wood is easy to saw, work and nail and is usually easy to dry without serious degrade.
- Farming: In some cases pine are also used in farming. General rotational period of pine is 30 year
- Food: large seeds also called pine nuts, that are harvested and sold for cooking and baking. They are an essential ingredient of Pesto alla genovese.
- Medicine: Some pine species are used to make some important ingredients which are used in medicines.