Pinus pinaster: Difference between revisions

{{shortShort description|Species of plant}}

| image = Pinus pinasterpinea and ruins on Palatine Hill.jpg

| status_ref = <ref name=IUCN"iucn status 19 November 2021">{{Citecite journaliucn | author = Farjon, A. |date=2013 |title = ''Pinus pinaster'' | journal = [[The IUCN Red List of Threatened Species]] | volume = 2013 | page = e.T42390A2977079 | publisher = [[IUCN]] | date = 2013 | url = http://www.iucnredlist.org/details/42390/0 | doi = 10.2305/IUCN.UK.2013-1.RLTS.T42390A2977079.en | access-date =19 9 JanuaryNovember 20182021}}</ref>

'''''Pinus pinaster''''', the '''maritime pine'''<ref name=GRIN>{{GRIN|name=Pinus pinaster Aiton|id=28525|accessdateaccess-date=4 November 2013}}</ref><ref>{{Cite web|url=http://www.wood-database.com/lumber-identification/softwoods/maritime-pine/|title=Maritime Pine &#124; the Wood Database - Lumber Identification (Softwood)}}</ref> or '''cluster pine''',<ref name=GRIN/> is a [[pine]] native to the south [[MediterraneanAtlantic Europe]] region and parts of the western [[Mediterranean]]. It is a hard, fast growing pine containingbearing small seeds with large wings.

''Pinus pinaster'' is a medium-size [[tree]], reaching {{Convert|20–35 |m|abbr=off}} tall and with a [[Trunk (botany)|trunk]] diameter of up to {{Convert|1.2 |m|ft|abbr=on|frac=2}}, exceptionally {{Convert|1.8 |m|ft|abbr=on|frac=2}}.

==== Ecological interactions ====

''Pinus pinaster'' is particularly successful in regions with fynbos vegetation because it is [[adapted]] to high-intensity fires, thus allowing it to outcompete other species that are not as well adapted to high-intensity fires. In areas of fire-prone shrubland, the cones of ''P. &nbsp;pinaster'' will release seeds when in a relatively high-temperature environment for [[germination]] as a recovery mechanism. This adaptation increases the competitive ability of ''P. &nbsp;pinaster'' amongst other species in the fire-prone shrubland.<ref name="Richardson" /> In a 3-year observational study done in [[Spain|Northwestern Spain]], ''P. &nbsp;pinaster'' showed a naturally high [[Regeneration (biology)|regeneration]] rate.<ref name="Calvo">{{cite book|first=L |last=Calvo |trans-titlefirst=Plant EcologyL | title=Post-fire natural regeneration of a ''Pinus pinaster'' forest in NW Spain |year=2008 |volume=197 |pages=81–90 |trans-title=Plant Ecology}}</ref> Observations showed a mean of 25.25 seedlings per square metre within the first year and then slowly decreased the next two years due to [[intraspecific competition]].<ref name="Calvo" /> So not only does ''P. &nbsp;pinaster'' compete with other species, they also compete within their own species as well. When the height of ''P. &nbsp;pinaster'' increased there was a negative correlation with the number of ''P. &nbsp;pinaster'' [[seedlings]], results showed a decrease in ''P. &nbsp;pinaster'' seedlings (r=–0.41, p<0.05).<ref name="Calvo" />

Several other characteristics contribute to their success in the regions they have invaded, including their ability to grow rapidly and to produce small seeds with large [[Conifer cone|wings]]. Their ability to grow quickly with short juvenile periods allows them to [[Competition (biology)|outcompete]] many native species while their small seeds aids in their dispersal. The small seeds with large wings are beneficial for wind dispersal, which is the key to reaching new areas in regions with fynbos vegetation.<ref name="Richardson" /> [[Vertebrate]] [[Seed dispersal|seed dispersers]] are not commonly found in mountain fynbos vegetation; therefore those species that require the aid of vertebrate dispersal would be at a disadvantage in such an environment. For this reason, the small seed, low seed wing loading, and high winds found in mountainous regions all combine to provide a favorable situation for the dispersal of ''P. &nbsp;pinaster'' seeds.<ref name="Richardson" /> Without this efficient dispersal strategy, ''P. &nbsp;pinaster'' would not have been able to reach and invade areas, such as South Africa, that are suitable for its growth. Its dispersal ability is one of the key factors that have allowed ''P. pinaster'' to become such a successful invasive species.<ref name="Richardson" />

In addition to being an efficient disperser, ''P. &nbsp;pinaster'' is known to produce [[Resins|oleoresins]], such as oily [[terpenes]] or [[fatty acids]], which can inhibit other species within the community from growing.<ref name="Santalla">{{cite book|first=L |last=Calvo |trans-titlefirst=Forest Ecology and ManagementL | title=Regeneration after wildfire in communities dominated by ''Pinus pinaster'', an obligate seeder, and in others dominated by ''Quercus pyrenaica'', typical resprouter |year=2003 |volume=184 |pages=209–223 |trans-title=Forest Ecology and Management}}</ref> These [[resins]] are produced as a defense mechanism against [[insect]] predators, such as the large [[pine weevil]]. According to an experiment done in [[Spain]], the [[resin canal]] density was twice as high in the ''P. &nbsp;pinaster'' seedlings attacked by the weevils compared to the unattacked seedlings. Since ''P. &nbsp;pinaster'' has the ability to regulate their production of defense mechanisms, it can protect itself from predatory in an energy-efficient manner. The resins make the ''P. &nbsp;pinaster'' less vulnerable to damage from insects, but they are only produced in high concentrations when ''P. &nbsp;pinaster'' is under attack. In other words, ''P. &nbsp;pinaster'' does not waste energy producing resins in safe conditions, so the conserved energy can be used for growth or reproduction. These characteristics enhance the ability of ''P. &nbsp;pinaster'' survive and flourish in the areas it invades.<ref name="Krebs">{{cite book|first=C |last=Krebs |trans-titlefirst=PearsonC | title=Ecology |year=2009 |trans-title=Pearson}}</ref> Both the traits of ''P. &nbsp;pinaster'' and the habitat in South Africa are conducive to the success of ''P. pinaster'' in this region of the world.

==== Options for biological control ====

[[Insects]] and [[mites]] that feed on the seeds and cones of ''P. &nbsp;pinaster'' can be effective [[biological control]] options. An insect or mite that acts as an ideal biological control should have a high [[Total fertility rate|reproductive rate]] and be [[Host (biology)|host-specific]], meaning that it preys specifically on ''P. &nbsp;pinaster''. The [[Biological life cycle|life cycle]] of the predator should also match that of its specific host. Two key characteristics the predator should also exhibit are [[Self-limiting (biology)|self-limitation]] and the ability to survive in the presence of a declining prey population.<ref name="Krebs" /> 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 ''P. &nbsp;pinaster'' seeds in the region is the key to limiting the growth and spread of this species because ''P. pinaster'' has the ability to produce a large number of seeds that are capable of dispersing very efficiently.<ref name={{sfnp|Moran|Hoffmann|Donnelly|van />Wilgen|2000}} One possible option is Trisetacus, an [[Eriophyidae|eriophyid]] mite. The main advantage to using this mite to control the population of ''P. &nbsp;Pinaster'' is its specificity to ''P. pinaster''; it can effectively control the population of ''P. &nbsp;pinaster'' by destroying the growing conelets in ''P. &nbsp;pinaster'' while limiting its impact to only this species. Another possible option is [[Pissodes|''Pissodes validirostris'']], a cone-feeding weevil that lays eggs in developing cones. When the [[larvae]] hatch, they feed on the growing seed tissue, preventing ''P. &nbsp;pinaster'' seeds from forming and dispersing. Although the adults feed on the trees as well, they do not do any damage to the seeds and only feed on the shoots of the tree, so they do not appear to negatively impact the growth of the trees. Different forms of ''P. &nbsp;validirostris'' have diverged to become host-specific to different pine trees. The type of ''P. &nbsp;validirostris'' that originated from [[Portugal]] appears to have specialized to ''P. &nbsp;pinaster''; therefore, this insect may be used in the future to control the spread of ''P. &nbsp;pinaster'' in South Africa.<ref name="Hoffmann">{{cite book|first=J |last=Hoffmann |trans-titlefirst=African EntomologyJ | title=Prospects for the biological control of invasive ''Pinus'' species (''Pinaceae'') in South Africa |year=2011 |pages=393–401 |trans-title=African Entomology}}</ref> The uncertainties regarding the host-specificity of different types of ''P. &nbsp;validirostris'', however, require more research to be completed before the introduction of the weevils into South Africa. An introduction of a species that is not host-specific to ''P. &nbsp;pinaster'' can lead to detrimental effects on both the environment and [[Industry|commercial (economics)|industries]] that are dependent on certain tree species. Two other biological control possibilities include the [[pyralid]] moth species [[Dioryctria|''Dioryctria mendasella'']] and ''D. &nbsp;mitatella'', but these species attack the vegetative [[Tissue (biology)|tissue]] instead of just the seeds of ''P. &nbsp;pinaster'', harming the plant itself.<ref name={{sfnp|Moran|Hoffmann|Donnelly|van />Wilgen|2000}} As of now, the eriophyid mite and cone-feeding weevil seem to hold the most potential to controlling the spread of ''P. &nbsp;pinaster'' in the regions it has invaded because they destroy the reproductive structures of the target invasive species.