Black pine (Pinus nigra s.l.) is the most widely distributed pine species in high-altitude areas in the Mediterranean Basin; Pinus nigra subsp.
Spanish black pine forests of the Gredos range are known for a long time (Gomez Manzaneque, 1988; Regato & al., 1992), although no phytosociological approach has been done so far.
Spanish black pine populations of the Spanish Central System are unique to peninsular level for being the only ones exclusively developed on siliceous substrates (granitic rocks, gneisses and micaschists) (Genova & Moya, 2012).
The following threshold of cluster A1 (truncation level of 11.15) clearly separates samples containing Spanish black pine (cluster A1b) from those without (cluster A1a).
It represents orotemperate submediterranean (orosubmediterranean) humid relict Spanish black pine mesoforests growing throughout the central and eastern Gredos Mountains (Figure 1, Table 4).
Cluster B2 represents pure Spanish black pine forests in the lower supramediterranean humid bioclimatic belt of the Gredos range (~900-1450 m asl), southeast oriented on the southern slope and northwest oriented on the northern slope of these mountains.
Then, around 1980, State Parks staff began noticing that the Japanese black pines were beginning to wither and die at Jones Beach, at other coastal state parks, and along stretches of parkways and highways.
Today, virtually all of the black pines that once thrived in the Long Island coastal zone are either dead or in danger of dying soon.
The worm-like, microscopic nematodes infected the black pines through wounds created by wood-boring insects such as the cerambycid, a long-horned beetle.
Brian Schneeman, an industrious young man working on an Eagle Scout badge, single-handedly raised more than $1,500 and, under the supervision of State Parks staff, purchased and planted 200 trees and shrubs in a five-acre tract previously populated by withered Japanese black pines.
The Japanese black pine (Pinus thunbergiana) also was easily propagated.
How did the deadly plague move so fast through the established plantings of Japanese black pine? Research determined that the culprit was the pinewood nematode (Bursaphelenchus xylophilus), first identified as a pine pathogen in the United States in Columbia, Missouri in 1979.