The major topics that trouble scientists and environmentalists - subjects that are relevant to the lives of all of us, including climate change, environmental pollution, ecosystems, agriculture, biodiversity, soil, and water - were discussed at the conference, together with a long list of others that are on the global agenda. KKL-JNF deals with these topics in various ways.
“The conference is a place for scientists, NGOs, decision-makers, and the general public to meet in order to advance environmental issues in Israel,” said the conference directors, Professor Michal Green, chairwoman of the Israel Society of Ecology and the Environmental Sciences, and Professor Dan Yakir, chairman of the annual Conference for Science and Environment, in their statement.
Preserving the Forests
Among the many subjects covered at the conference, one session about KKL-JNF’s forests aroused special interest among the participants. The lectures addressed the various aspects of monitoring as a tool for sustainable forest management.
Asaf Karavani, KKL-JNF’s Coordinator for Research and Foreign Relations in KKL-JNF’s Afforestation Division, began the session by saying: “I meet many young people who desire to enter the forestry field, and that gives me a great deal of hope for the future. KKL-JNF will continue to support anyone who works in this field by providing assistance to students, research grants, accessibility to information, and initiating collaborations.” About KKL-JNF’s forests, he said, “Each forest has its own purpose, and we adapt the desired management interface to it. Monitoring enables us to learn while doing.”
Yahel Porat, KKL-JNF Afforestation Division Ecology Director, presented long-term research on the nesting of diurnal raptors in KKL-JNF’s coniferous forests. “The term pine deserts that was used in the past is not applicable anymore, and we are finding biodiversity in the planted coniferous forests,” he said. “Since our goal is to nurture and preserve the forest as a supporter of biodiversity, we must examine what we know about what exists in the forest and what we must do in order to preserve it.”
He explained that the purpose of KKL-JNF’s monitoring program, which began approximately five years ago, is to check the abundance of raptor species, examine the effect of the forest landscapes and the effect of the human activity in the forest, and map the nesting areas. “KKL-JNF foresters have been participating in the process since it began,” he said. “This increased awareness of the importance of protecting the raptors in their forests.”
Six large forests, from the Negev
to the north
of Israel, were chosen for monitoring: Yatir
l and Tzora
, Ramat Menashe
, and Biriya
and monitoring of raptors are done in each forest, and seven species have been located so far: the short-toed snake eagle, the common kestrel, the Eurasian sparrow hawk, the Eurasian hobby, the long-legged buzzard, the black-winged kite, and Bonelli’s eagle.
The survey found that even those forests with many human visitors and activities have raptor nests. “We did not know that there was such a variety of raptors in the coniferous forests. It was very surprising to find that out,” he said. “We learned that most of the raptor species that exist in Israel nest in forests as well.”
The database and the maps are given to foresters to use as tools in managing the forest. Among the practical instructions that have already been issued to the field are to avoid thinning trees during the raptors’ nesting season.Yotam Perelman
of the Volcani Institute presented findings from the long-term monitoring system of the pine forests in Jerusalem
and their implications for forest management. “Israel’s pine forests are undergoing a change from a simple structure to one that is more complex - multi-age, multi-species, and multi-layer,” he said. “The way the forests are managed is changing accordingly.”
The study included surveys of vegetation, optical measurements, and measurements of leaf area. The most significant factor affecting total leaf area was found to be the amount of humidity in the habitat. These data match those of research that has been done all over the world.
The question arises as to how monitoring affects management - or, as Perelman put it, “What can we do with that?” It turns out that a density level of 30 to 35 trees per dunam is an upper threshold, beyond which density does not contribute to leaf area because the trees begin to compete with one another, and each develops a smaller leaf area. This statistic is true of all areas in Israel.Shani Gleitman
, an ecologist at the KKL-JNF Afforestation Division, offered some new perspectives on dealing with invasive species in the forest
. “Invasive species affect biodiversity, agriculture, the economy, public health, and the functioning of ecological systems,” she said. She cited as an example the small fire ant, which was first seen in Israel in 2005. “This ant hurts agriculture, quality of life, and public health,” she said. “The damage it causes is estimated at approximately one billion shekels per year.”
How are invasive species dealt with? “We prevent invasive species from being imported, reduce their spread to new areas, and exterminate species that have already invaded and established themselves in the forest,” Gleitman said. “That is why monitoring, mapping, species prioritization, spatial prioritization, and repeated treatment are required over the years.” As an example, she cited ragweed
, a plant that is in the first stages of invasion in Israel. KKL-JNF workers are mapping, monitoring, and offering foresters professional assistance in dealing with it. Another well-known invasive species in Israel is the blue-leafed wattle
tree (Acacia saligna
), which established a large population in the Ben Shemen Forest
. Thanks to repeated treatment over the years, the presence of this species in the forest has diminished.
Dr. Tamir Klein
of the Weizmann Institute presented an analysis of tree mortality as an outcome of climate change
. There is no organized information anywhere on earth about the scope of this occurrence. An important study, conducted by KKL-JNF, was begun at the Weizmann Institute’s Tree Lab to examine whether tree mortality has increased since the establishment of the State of Israel, whether it has to do with climate change, and which species are particularly affected. The data were gathered from a variety of sources, from historical accounts of KKL-JNF foresters from years past to current satellite images.
Dr. Klein gave four main reasons for tree mortality in Israel: fires
, drought, pests
, and snowstorms. The survey revealed that approximately half of the tree mortality was caused by fires, and a quarter of it was caused by drought - which, of course, encourages fires, and also makes the trees more vulnerable to pests
. It was found that tree mortality has risen since 1991. Broadleaf trees were found to have higher survival ability than conifers.Omer Golan
, Director of the KKL-JNF Afforestation Division Forest Health and Protection Department, spoke about coping with tree drought and mortality
, with emphasis on the damage caused by bark beetles. “A forester who wishes to treat a forest asks himself where the damage has appeared and the extent of its severity,” he said. “An answer can be obtained only through surveys.” Since it is not always possible to reach and survey every part of the forest, KKL-JNF officials decided in 2017 to begin aerial surveys, which create maps that show the dry areas. “These maps serve foresters as treatment tools for the forest,” Golan said.
At the close of his remarks, he said, “The Afforestation Division encourages collaborations in conducting studies on the topic so that our forests will be prepared for climate change and for the future.”
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