NATURAL AND UNNATURAL ENEMIES

Jerusalem pine trees have a natural life expectancy of eighty to one hun-dred years; if irrigated, they may live to be 150. In fact, only a fraction sur-vived that long. The pine forests of both the British and the JNF were under a constant state of siege prior to 1948. Arson and other forms of what Mandate officials called “political sabotage” were a constant problem for the JNF; the Jerusalem pine's flammable sap literally added fuel to the proverbial flames. During the Arab Revolt of 1936, vandalism became so violent that JNF planting efforts became unsafe. This led to a strategy of pairing a young forest with an adjacent kibbutz that could protect it. The Arabs saw the forests as easy military targets, and, in fact, the young forests were used to conceal the illegal bunkers and clandestine military training of the Haganah and Palmach.

In retrospect, the Arab disturbances proved counterproductive. The JNF defiantly planted one million saplings between 1936 and 1938, almost dou-ble previous afforestation efforts.^[82] The arson doubly backfired, much as the Intifada would fifty years later: While foresters became more vigilant, JNF fund-raisers were quite adept at exploiting the destruction of helpless trees. The JNF budget expanded considerably in the late 1930s, as a sym-pathetic Jewish public around the world dug into their pockets to fight the flames with record donations.^[83]

But the greatest threat to the young forests was not from fires but from insects—in particular an aphid known locally as the Jerusalem pine blast (Matsucoccus josephi). Lipshitz and Biger's research suggests that as early

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as 1933 the first definitive scientific identification of the blasts was made on the Carmel.^[84] Damage to trees from this persistent airborne pest in-cludes both acute and chronic injuries. The crawlers love everything about Jerusalem pines, settling on all parts of the tree that lie above ground. The preferred sites are the partially smooth stem sections with scaly bark in mature trees and the buds and the base of the fast-growing shoots. The pests dry out the branches and in acute cases cause the death of the tree within months. When damage is chronic, the process can last for decades, as limbs slowly dry and atrophy.^[85]

In 1935, with a 70 percent loss in the Mishmar ha-Emeq forest, JNF forestry officials could no longer ignore the scourge. A formal scientific survey revealed that, in contrast, the stone pines in the forest were un-harmed.^[86] Several of the Yishuv's top botanists, including Hebrew University professors Hillel Oppenheimer and Fritz Bodenheimer, were enlisted in the research efforts. (Oppenheimer's site visits to the JNF's northern forests were coordinated by Sharon Weitz, Yosef's middle son, who had already joined his father's afforestation department and would eventually run it.) The chief government entomologist, Dr. Karl Shveig, identified other problematic pests such as the caterpillar Evetria rhyacca buoliana (nicknamed by Shveig the “Pine Fire”). But the biological detec-tives explicitly singled out the Matsucoccus blasts as the key guilty party.

There was little the entomologists could do to help, however, particu-larly once the upper branches of trees became infested. This scientific im-potence was apparent in October 1938 when Professor Oppenheimer sub-mitted his report to Weitz. The professor sounded a clear warning about the long-term implications of the pest problem: “After the disease has spread to such a great extent, I doubt if we can continue to successfully grow forests comprised only of densely planted Jerusalem pines.”^[87] The warning went unheeded. Although allowing for some diversity among its conifers, on the whole JNF managers remained obtuse for forty years. Planting policy eventually changed, but as recently as 1969 JNF literature still hailed the Jerusalem pine as its flagship species.^[88]