Background:

Oaks (Quercus calliprinos) woodlands growing in marginal water limited habitats of Israel are under serious threat of oak decline induced by climate change. Livestock grazing is one of the few tools available for effective, large-scale vegetation management in drylands, but our understanding of the impact of grazing on the water relations, growth and survival of trees under drought is very limited.

The objective of this project is to assess the impact of grazing on water relations and performance of oak trees as keystone species in the climate-vulnerable transition zone of Israel. This project also aims to assess oak populations growing in marginal, water-limited habitats to develop a set of environmental and biological indicators of their vulnerability to drought.

Additionally, the oak site will be compared with a nearby planted Aleppo pine forest.

In this project an eco-hydrological model which describes woodland structure, and oak performance and survival along aridity and grazing gradients will be developed.

Impacts of climate change on oak woodlands at the dry tree line: Forecasts predict massive range retractions of oaks under climate change. However, the heterogenous relief of the study region, the southern Judean foothills, may enable oaks to persist in climatic refugia despite an overall drought increase. Additionally, the positive impact of cattle grazing on the oaks' water status may contribute to a stabilization of the dry tree line. To anticipate the response of the most southern oaks to climate change, we will combine data from different ecological levels. Therefore, the collection of eco-physiological data and a demographic set up and a ecohydrological model will be made. This will allow the analysis of climate change effects on oaks at the individual, population and ecosystem level. Finally, it will enable the development of a climate change adapted strategy for sustainable dryland management.

Collaboration: Yagil Osem, Agricultural Research Organization, Bet Dagan, Israel, Efrat Sheffer, Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot, Israel , Yael Mandelik ,Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot, Israel, Frank Schurr, The Hohenheim University Germany, and Britte Tientjen , The Freie Universität Berlin. 

Co-workers: 

Omri Hasson (formr PhD student and postdoc), Simon Ludovicy (PhD student), Dor Pinchevsky (former Msc student)