In many drylands, key invasive plant species belong to the genus Prosopis spp. (mesquite) known to have a negative impact on native biodiversity and on water availability to native trees and shrubs with shallower root system. Moreover, mesquite has a potential to increase soil erosion rates due to modified root structure, and more nitrogen supplied to the newly colonized ecosystems may significantly impair water quality. In Israel, exotic Prosopis species are widely used as ornamental plants and have been purposely planted in arid and semi-arid regions since the 1960s. A recent survey reported that multiple planted populations of Prosopis became invasive and currently invade 690 km2 of the Dead Sea area, Negev desert, Jordan Valley and the Arava Valley. Despite the increasing presence and very high risk of invasiveness, the impact of Prosopis encroachment on ecosystems and the environmental conditions prone to invasions in Israel are currently unknown, although consequences for plant communities and function of ecosystems were anticipated. There is a major knowledge gap in our understanding of the environmental factors conducive to invasion by exotic Prosopis species in Israel and the ecosystem consequences of such invasion events.
The objectives of the project are to understand the edaphic, hydrologic, geophysical and climatic conditions conductive to the invasion by Prosopis spp. To assess ecophysiological performance and traits related to successful Prosopis invasions by comparing the performance of Prosopis individuals to native Acacia trees. To evaluate the ecosystem-scale changes imposed by Prosopis invasion on the carbon and nitrogen cycles, and the composition of plant communities, and to develop practical guidelines for the effective prevention of further invasion by Prosopis spp. around the Dead Sea.
Collaboration: Ilya Gelfand, French Associates Institute for Agriculture and Biotechnology of Drylands, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev
Co-worker: Alon Levinzon (MSc student)