MedPine 6: The 6th International Conference on Mediterranean Forest Ecosystems

Asaf Karavani, KKL-JNF’s Coordinator for Research and Foreign Relations and organizer of MedPine 6, welcomed the guests. Karavani said that this year, the conference focused not only on the scientific ecology of trees but on the whole question of forest management as well.

“A large part of the 4-day itinerary was devoted to field trips. I am happy to note that amongst the participants were many KKL-JNF foresters and field workers who were happy to give lectures and share their hands-on experience. Our purpose was to climb out of the ivory tower of pure academics and bring our knowledge to a level of forest management, where we can implement change.”

This was the second time that the conference was held in Israel, the first time was MedPine 1, which took place in Haifa in 1999.

The conference was opened by Dr. David Brand, who is KKL-JNF’s Chief Forester, and Professor Zohar Kerem of the Hebrew University’s Faculty of Agriculture, Food and Environment in Rehovot, where the event took place.

Dr. Brand told the audience that the purpose of the conference is to pass on knowledge and to help one another. He said that it is also a wonderful opportunity for KKL-JNF to present and share its own achievements in the ecology of Mediterranean forests, and that of arid areas. “Over the last four to five years KKL-JNF has successfully revised many of its practices in order to deal with the changing climate conditions, and there is a great demand for this knowledge. We are happy to share.”

Looking at the large audience in the lecture hall, Prof. Kerem said that he was not surprised to see so many of his colleagues in attendance and that the Hebrew University’s Faculty of Agriculture, Food and Environment in Rehovot is a natural venue for such a conference to take place. “I hope it will become a tradition to hold it here in the future. Let us not forget that throughout history, crises led to innovation. Today, agriculture is in crises to meet the challenges of food production. One of the ways to deal with this is certainly to protect our forests, which help regulate carbon dioxide and nitrogen levels and other pollutants.”

 

Mediterranean Forest Dynamics was the title of the first session of the conference. Professor Avi Perevolotsky of the Department of Agronomy and Natural Resources at the Volcani Center delivered the opening paper, on “Pine-oak relations: an emerging novel ecosystem or a reason for organizational conflicts.” Perevolotsky’s research over the past decade explored natural processes and management of planted pine forests, in light of principal ecological processes such as forest succession, pine-oak relations, and the impacts of droughts.

“Pines have been part of the eastern Mediterranean flora for millennia”, said Perevolotsky. “As a sole source of timber, humans heavily exploited these pines. By the end of the 19th century, only a few groves of native pines survived in the Land of Israel. The fate of the native woody formations, dominated by oaks, was not different. They had been burned, cut and heavily grazed for centuries. Early in the last century, KKL-JNF began massive afforestation which intensified after the establishment of the State of Israel. Today, planted trees, mainly pine, cover some 5-7 % of the country. The question now is how to manage the ecosystem of a planted forest vis-à-vis mature oak woodland. Conservationists consider the colonization of pines within oak stands in nature reserves as a biological invasion. Perhaps the self- creation of a novel ecosystem due to spontaneous ecological processes is inevitable and corresponds with the pristine climax community conditions of the region.”

A presentation entitled Evolution of Israeli forestry from pure even-aged pine plantations to sustainable uneven-aged mixed forests was delivered by Dr. Omri Boneh, KKL-JNF Chief Scientist and head of the Northern Region.

“A massive dieback of 40-year-old planted Aleppo pine stands, attributed mainly to an outbreak of the Israeli pine bast scale (Matsucoccus Josephi) in the early 1970s led to the use of other pine species, mainly Pinus brutia, instead of Aleppo pine”, Boneh noted. “Toward the late 1980s, the use of native broadleaf species in forest plantations in addition to coniferous species was dramatically increased. In 1990 the KKL-JNF Forestry Division revised its forest policy. The new policy aimed to create mixed, multi-layered, well-spaced forests with higher tolerance and better resilience to climate-change impacts such as drought, fire, and insect infestations.”

The next paper, on the Impact of canopy cover and dry-season conditions on litter decomposition in Mediterranean pine forests, was presented by Dr. José Grünzweig of the Hebrew University’s Faculty of Agriculture, Food and Environment.

“This study investigated the impact of canopy cover and seasonality on litter decay in Mediterranean pine forests”, said Grünzweig “Decomposition is a key process in the cycling of carbon in ecosystems, but it is unclear how it will be affected by climate changes in drylands. We conducted litterbag experiments in plots of different tree densities in a semiarid and a dry-subhumid Mediterranean pine forest for 613 days. Litter mass loss was greater in forest gaps than under tree canopies in both forests.”

Modelling regeneration occurrence in a mixed Mediterranean forest through survival analysis was the subject of a paper delivered by Marta Vergarechea of the Forest Research Center (INI-CIFOR) in Madrid, Spain.

“Natural regeneration is commonly unsuccessful in Mediterranean pine forests”, noted Vergarechea. “It is important not only to identify the factors that affect regeneration occurrence but also to determine how their effects can be modified through different management options.”

Hugh Safford, a senior vegetation ecologist with the U.S. Forestry Service - Pacific Southwest Region, described his research: Recent bark beetle outbreaks and subsequent wildfire severity in mixed-conifer forests of the Sierra Nevada, California, USA.

“Insect and drought-induced tree mortality dramatically increased in the Sierra Nevada during California’s recent prolonged drought, causing widespread concern that severe tree mortality would lead to increased severity of subsequent wildfires,” said Safford. “We found that native Mediterranean trees are very drought adaptive and prolonged droughts will kill some and weaken others. The weak trees will be susceptible to bugs and fungi attacks and subsequently to fire. Our results demonstrate that high pre-fire mortality of conifers in a Sierra Nevada mixed-conifer forest has a positive influence on fire severity when dead needles are retained on the beetle-killed trees.”

Safford reminded the audience that California is one of the areas outside the Mediterranean Basin which also enjoys a Mediterranean climate, such as in the Southern tip of Africa and Western Australia. He said that he is fascinated by the way Israel started with very little green open spaces and managed to create so many more for the benefit of its citizens.

Dr. Yehoshua Shkedi, Chief Scientist at Israel's Parks and Nature Authority spoke on Pinus halepensisin nature reserves – data, emotions, and policy. He described a situation where while the mass tree planting in Israel had a positive impact on the local landscape, the project also interfered largely with the various indigenous species.

“KKL- JNF, which serves as Israel's forestry service, has changed the landscape dramatically, planting pines from the Lebanese border to the Negev highlands over the past 100 years. The result is that most of Israel is rich in pines that produce large quantities of seeds and seedlings. KKL-JNF used seeds of P. halepensis imported from various regions in the western Mediterranean for the afforestation, rather than the local eastern type. Since the planted forests cover extensive areas, occurring usually in proximity to remnant stands of natural populations, there is no real possibility of conserving the local type with its unique genes.”