Pines in the Nahal Kisalon forest, Tomer Appelbaum
Pines in the Nahal Kisalon forest. Photo by Tomer Appelbaum
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The Jewish National Fund forests in Nahal Kisalon in the Judean Hills have survived diseases, pests and fires. But travelers through the forest will notice an increasing number of trees turning gray and white. They are still standing, but they are drying up and nearly dead.

Forestry experts and researchers in the Agricultural Research Organization's Volcani Center are concerned that Israel's forests are drying up and dying due to a series of drought years and climate changes. Now, scientists at a new research center in Nahal Kisalon are trying to better understand what is happening to Israel's forests and to develop forests that can face long-term climate changes and meet growing recreational needs.

"We believe that climate changes and drought years could make things even worse for trees that are already at risk from pests and disease," Prof. Avi Perevolotsky, of the Agricultural Research Organization, says.

The forests around Jerusalem, which cover thousands of acres, were planted 40 and 50 years ago. The Kisalon Forest, like many others in the area, is full of various kinds of pines, including the Jerusalem pine. While the latter does grow naturally in Israel, it never covered such large areas as it does now, after the Jewish National Fund created the conditions for its spread.

Many of the pines on the slopes of Nahal Kisalon are at an advanced stage of desiccation. Nearby are stone pines, brought to Israel by the Romans 2,000 years ago, also slowly dying. "What we see here is that Israel's forests are suffering from symptoms of a system that is unsuitable to its environment, especially in terms of surviving a dought," says Yagil Osem, also of the Agricultural Research Organization.

The JNF is trying to decide what to do with the dying trees. Removing them could prevent the spread of disease, but according to the JNF's Hanoch Tzoref, dragging them out of the forest causes damage to the ground and is very expensive.

"The forest in Israel has not been studied enough and we don't have answers," Tzoref says.

According to Perevolotsky, there are hardly any forest researchers in Israel, and without a new generation in this field, it will be hard to protect the forests.

Many scientists and forestry experts believe that the time has come to plan woodlands that are suitable to hot, dry conditions and will meet the increasing recreational needs. Only about 10 percent of the forest is needed for recreation; the rest can meet ecological goals of landscape conservation and biodiversity of flora and fauna. Even now, gazelles can be seen frequently, bounding across the paths and the cliffs of Nahal Kisalon.

"Instead of planting, we'll have to encourage natural growth of forests with a wide variety of species," Osem says, adding that the process will involve thinning out sick and weak trees to make way for stronger ones.

A wide variety of instruments at the Nahal Kisalon research station that measure the age, growth and physiological responses of trees are "checking how the trees feel," according to Perevolotsky. "Clearly, what will determine the future of the forest will be determined by how trees take advantage of water, and that one of the main things we are trying to check," Osem says.