Jerusalem Corridor Fire Update
(IFFN No. 15 - September 1996, p. 6-10)
Since my initial report (IFFN No.13), a great deal has happened, both with regard to a more detailed determination of the fire's effects and in the area of planning and management activities for the regeneration the burned area. In this update I will summarize our efforts in the following areas:
- Fire effects
- Report by a soil conservation expert
- Initial planning
- Management activities already carried out
- Detailed restoration plan
- Utilization of a Geographic Information System for planning and management support.
The burned area has been determined to be 1250 ha. This is considerably less than the initial estimate of 2000 ha, but it still ranks as the largest forest fire in Israel's history, and about one percent of our forested area. This can be broken down into 400 ha of open areas, 100 ha of natural forest (maquis) and 750 ha of planted forest, about half of which was more than 30 years old. The planted stands were mostly conifer (pines and cypresses) while the natural forest included oaks, pistachios, carobs and olives. A significant fraction of the conifers was killed without the canopy being burned as the fire raced along the ground. For the most part, the broad-leaved trees were not killed and many are now vigorously resprouting. During the first winter after the fire there was little flooding, and only slight damage to forest roads in sensitive areas. A total of twenty-five houses that were partly or totally destroyed are being rebuilt with government financial assistance
Hydrology and Soils Analysis:
During the initial planning stage after the fire, the Jewish National Fund (JNF), Forest Department, received an offer of assistance from the Chief of the USDA Forest Service to send a person experienced with fire rehabilitation to visit Israel. Mr. Bruce McCammon, a regional hydrologist with the Forest Service arrived in late summer and spent two weeks visiting the burn site, for visual surveys and soil testing, and meeting with JNF experts. The JNF presented two questions for which they wanted specific thoughts and recommendations:
- What should be done with the remaining dead vegetation?
- How can "buffer zones" be established near population centres to minimize future damage from wildfires?
Mr. McCammon's report included an immediate fire rehabilitation assessment, recommendations for dealing with remaining dead vegetation, and planning suggestions for future fire protection.
It was necessary to evaluate the fire's intensity, since burn intensity is strongly correlated with the development of emergency watershed conditions. The fire exhibited characteristics typical of a wind-driven fire that moved rapidly across the area, sometimes in the crown and sometimes on the ground. For this reason and because there was sparse ground cover in many places, the burn was characterized by low to moderate burn intensities. Even in areas where the entire canopy was consumed, the short fire residence time resulted in only partial consumption of the ground vegetation and did not create hydrophobic soils.
As a result of the lack of hydrophobic soils and the extensive surface rock cover (creating surface roughness) in the area, the report concluded that accelerated surface erosion in the burned area should not be a significant problem. In the most sensitive areas, the greatest potential for erosion will occur during the first year after the fire due mostly to the loss of overstorey and understorey canopy. Sprouting of deciduous species is already common in the burn area. Extensive terracing in the area also reduces surface flow rates. Mr.McCammon recommended protecting the terraces and chipping and spreading remaining limbs on unterraced slopes. This is particularly important for steep slopes located above the Tel Aviv-Jerusalem highway. To prevent rock-fall on the highway, dead trees should be felled and oriented perpendicular to the slope.
With regard to the remaining dead vegetation, the report recommended to remove commercial conifers. Their limbs as well as the smaller non-commercial conifers and burnt broadleaf stems should be chipped and spread on-site to provide protection and additional nutrients for the soil. Broadleaf trees which resprout vigorously need to be pruned or grazed to prevent the development of a dense thicket. This can become impassable and is also a significant fire hazard.
Finally, it was recommended to establish "buffer zones" near settled areas to reduce fire initiation or spread. These plantings are characteristically composed of species that are shorter, less susceptible to ignition, and planted at a lower density than normal. The understorey can be maintained to minimize fire risk through a combination of grazing, mechanical methods and prescribed fire.
Overall Planning Guidelines:
The planning unit in the Central Region of the JNF Forest Department has moved quickly and by October 1995 completed overall planning guidelines for the restoration of the burned area. These guidelines delineate five major landscape elements which exist in the burned area and must be taken into account in its restoration.
- Planted Conifer Forest With Natural Woodland Understorey: Establishment density will vary according to intended use (denser in campgrounds). Natural conifer regeneration will be utilized where possible. Planted conifers will include: Brutia pine, Aleppo pine, Stone pine and Cypress. Where the broadleaf (evergreen and deciduous) understorey establishes well, it should be encouraged through selective thinning of the conifers.
- Natural Woodlands: Existing groves need to be maintained by pruning them as they resprout in order to prevent the development of a dense thicket.
- Olive Groves: Existing groves need to be maintained though cultivation and pruning. When the need arises they should be "filled out" by transplanting mature trees from other areas of the Central Region.
- Orchards: These are small in total area but have great scenic potential as they adjoin the major highway. To reduce maintenance costs, it is recommended that these be restored as "quasi-orchards" containing Palestinian and Atlantic pistachios, Worm oaks and Stone pines.
- Buffer Zones: These act as barriers to reduce the likelihood of fire ignition and spread near and into settled areas. Their forest density will be kept low (300-400 stems/ha), and ground fuels loading will be kept at a minimum through ploughing, grazing, and the use of herbicides where necessary.
These five zones were mapped for use as a framework for the detailed restoration plan. In addition, planning guidelines were established including focus on the unique physical characteristics of the area (topography, terraces, landmarks, and lookout points), stress on the importance of utilizing local flora, and the need for long-term recreation and tourism planning in the fire-affected areas.
Our initial management conception has been to perform the minimum actions required which accord with the overall planning guidelines and, at the same time, to gather detailed field data to support the continuing planning process. With this in mind, some 7000 tons of commercial timber have already been harvested, priority being given to slopes above the main highway. Of about 5000 tons of slash and non-commercial conifers and broadleaf trees, about two-thirds being chipped and spread as mulch and the rest used to stabilize particularly sensitive slopes. Some 100 ha of natural broadleaf groves have been treated (i.e., dead wood pruned and chipped; Fig.2). These are now vigorously resprouting.
Detailed surveys have been completed of the following characteristics:
- natural vegetation types
- natural vegetation regeneration
- soil types
- terraced areas (ancient and modern)
These data are being digitized and will be available as map layers through our GIS unit (see below).
Detailed Restoration Plan:
Due to the scenic and historic importance of the fire site, an internationally known landscape architect, Shlomo Aronson, was chosen to draw up a detailed restoration plan.
There are two general stages to this planning process:
data collection (during which time an overall concept is formulated) and drawing up of the plan itself. The first stage is nearly complete. Data collected include those from the four surveys mentioned above and, in addition:
- archaeological sites
- historical sites
- recreation and tourism sites
- infrastructure, existing and planned (water, electrical, sewer, telephone, roads)
The development of an overall concept takes these background data together with an integrated sense of the site's characteristics as a landscape unit. Among the these characteristics are:
- geographically, a transition area from the foothills to the Judaic mountains.
- the beginning of the "ascent to Jerusalem" for both pilgrims and tourists.
- an area where fierce battles were fought to break the blockade of Jerusalem during Israel's Independence War.
- an area richly endowed with natural and man-made terraces attesting to its agricultural importance.
Fig.1. A three-dimensional map showing the burn area, surrounding forest, and nearby settlements (black squares). The view looks east, up into the hills in the direction of Jerusalem. Ignition occurred in the small patch closest to the viewer, west of the intersection.
Fig.2. Salvage logging along the Tel Aviv - Jerusalem Highway in October 1995
The final plan must weave these elements and their implications together. The high potential for recreation and tourism is clear. Yet this must be reconciled with the need to preserve the natural resources and protect the great beauty of an area whose visual impact alone can hardly be exaggerated.
From the first stages of planning immediately after the fire, the GIS Unit of the JNF Forest Department has been an invaluable tool. Luckily, the Israel Mapping Authority's National GIS Project had already completed digital mapping of the area with the burn site, giving us the basic background of topography, roads and settlements. Thus, within a few weeks after the fire, a basic map of the burned area was already made available to foresters and planners. By the time the US Forest Service hydrologist arrived, he was provided with additional GIS maps including watershed boundaries, soil types, soil conservation zones, and an analysis of visibility from the main highway. The GIS Unit has provided the standards for the data collection on which the detailed restoration plan will be based, and will be the major producer of maps for this plan. Since a Digital Terrain Model (DTM) was available from our national mapping authority, GIS analyses became the "data source" for such layers as slope, aspect, and topography. Essentially all the site data mentioned in this report are being stored as data layers by the unit for future analyses. Maps are generally produced by a plotter in colour to provide maximum information with optimal clarity. To give some idea of the GIS's potential contribution to planners, I have included a three-dimensional perspective of the burned site (Fig.1).
A Final Note: The results of fire are not only negative, especially in a Mediterranean biogeographical zone with a long history of anthropogenic (man-caused) fires. In this context, it is noteworthy that in the burn area there have appeared many brightly flowering geophytes, especially those in the tulip and orchid families, in places where they were thought to have disappeared.
This report relies heavily on extracts and summaries from the reports listed below, other internal Forest Department documents, and conversations with the Hanoch Zoref, the forester responsible for the burned area:
Ben-Moshe, M. 1996. Thoughts on the restoration of the Jerusalem Corridor burn area. Shlomo Aronson Architects, internal memo <in Hebrew>.
McCammon, B.P. 1995. Evaluation and recommendations for short-term rehabilitation and long-term recovery of the Jerusalem Corridor Fire. Internal USDA Forest Service report, prepared for the JNF Forest Department.
Projects Division, Jewish National Fund. 1996). Up from the ashes: the regeneration of the Sha'ar Hagai forests.
Tauber, I. 1996. Aid for the Jerusalem Corridor Restoration Plan by the Forest Dept. G.I.S. Unit. Forestry Data Unit, internal memo <in Hebrew>.
From: John Woodcock
Data Base Manager
Jewish National Fund, Forest Department
P.O. Box 45
IL - Kiryat Haim