Dunes Wonderland Trail #11: Problematic Pinaster
The 11th cache in this 12-cache series, a camo-taped preform tube, is hidden in a large rock outcrop near the eastern pedestrian access gate for the adjacent golf course. For details of the trail, see GCA3BT8 DWT#1.
The hiding of this cache became possible with the archiving of Marais Geo Sniffers!’ cache GC56341 Pied pipeR which was hidden nearby on 1/6/14 and archived on 21/12/22 after some 40 finds.
Its location is shaded by a wonderful but potentially problematic mature tree – one of a pair – which has shed its distinctive leaves profusely around GZ.
Note: the 2.5 terrain rating assumes you are doing the cache in sequence. otherwise it is 1.5 as an easy Park 'n' Grab!
To Reach the Cache:
a) Continuing in sequence: from #10 continue following the track passing the location of Skattie@1’s cache GC9G478 Clovelly golf course. At the end of the car park continue down and past the front of the clubhouse to the lower car park and access gate in the corner. The cache location is just through this up the small trail on the left.
b) As a one-off or alternative series starting point: park at or near S 34 7.403 E 18 25.786 at the end of Montrose Avenue. The cache location is across the road just up from the corner.
The trees at GZ are maritime or cluster pines (Pinus pinaster) native to the south Atlantic Europe region and parts of the western Mediterranean. It favours a Mediterranean climate - one with cool, rainy winters and hot, dry summers. It is a hard, fast growing, medium-size tree, reaching 20–35m with a trunk diameter of up to 1.2m, exceptionally 1.8m.
The bark is orange-red, thick, and deeply fissured at the base of the trunk, somewhat thinner in the upper crown. The long leaves ('needles') are in pairs, very stout, and bluish-green to distinctly yellowish-green. The cones are conic, green at first, ripening glossy red-brown when 24 months old. They open slowly over the next few years, or after being heated by a forest fire, to release the seeds. The small seeds have large wings and are wind-dispersed.
It generally occurs at low to moderate altitudes, mostly from sea level to 600m, but up to 2,000m in the south of its range in Morocco.
It is a popular topic in ecology because of its problematic growth and spread in South Africa for the past 
150 years after being imported into the region at the end of the 17th century (1685–1693). It was found spreading in the Cape Peninsula by 1772. Towards the end of the 18th century (1780), it was widely planted, and at the beginning of the 19th century (1825–1830), it was planted commercially as a timber resource and for the forestry industry.
It invades large areas – particularly fynbos vegetation, the fire-prone shrubland vegetation which is found in the southern and southwest cape area. It is found in greater abundance close to watercourses. One of the results of this is a decrease in biodiversity. The increase of extinction rates of native species is directly related to the introduction of this species. Overall, invasive species have the potential to decrease the diversity of native plants by 50–86% in the Cape Peninsula.
In addition, depending on the area invaded it may dramatically alter the quantity of water in the environment because it is evergreen and takes up considerably more water than, for example, grasses and shrubs all year around. It grows rapidly in riparian zones, such as near the seasonal stream at GZ, with abundant water where trees and plants grow twice as fast and invade. It takes advantage of the water available and consequently reduces the amount of water in the area available for other species.
As a result of invasive growth, there is often less understory vegetation for livestock grazing causing a decrease in livestock. When it is removed and agreeable range grasses were planted, grazing conditions are greatly improved and stock numbers increase.
It is particularly successful in fynbos regions because it is adapted to high-intensity fires, allowing it to outcompete other species not as well adapted. In such areas its cones release seeds when in a relatively high-temperature environment for germination as a recovery mechanism. This adaptation increases itsompetitive ability amongst other species.
Its small seeds with large wings are beneficial for wind dispersal and key to reaching new areas - one of the main reasons it has become so invasive.
It also produces oleoresins which can inhibit other species within the community from growing. These resins are produced as a defence mechanism against insect predators, such as the large pine weevil. The resins make it less vulnerable to insect damage, but are only produced in high concentrations when it is under attack. So, it does not waste energy producing resins in safe conditions and the conserved energy can be used for growth or reproduction.
Various biological control methods are employed to control its growth and spread and relevant research continues to identify effective solutions. Seed-feeding insects are an effective control because they have high reproductive rates and target the seeds without diminishing the positive effect of the plant on the environment. Controlling the spread of its seeds is key to limiting its growth and spread because of its ability to produce large numbers of seeds which can disperse very efficiently. See here for a paper on this issue.
Uses: it is widely planted for timber and is a useful source of turpentine and rosin. It is also a popular 
ornamental tree, often planted in parks and gardens. It has become naturalised in parts of southern England, Uruguay, Argentina, South Africa and Australia.
It is also used as a source of flavonoids, catechins, proanthocyanidins, and phenolic acids. Pycnogenol, a dietary supplement derived from bark extracts is claimed to treat many conditions (see here and here for example). However, as is almost always the case with ‘miracle’ products, despite some glowing anecdotal ‘reviews’ and some promising signs of useful physiological effects, there isn’t yet sufficient clinical evidence to support its use - further research is required.
