Planting Acacia Victoriae Trees in Rangelands to Increase Land Productivity and Grazing Sustainability.

Planting Acacia victoriaetrees in rangelands to increase land productivity and grazing sustainability

Amir Mor-Mussery^1,2, Stefan Leu², David Helman³ and Pua Bar (Kutiel)¹

¹Department of Geography and Environmental Development Ben Gurion University of the Negev, Beer Sheva

²Leu-Sella Environmental Development, Ben Gurion College, Israel

³Bar Ilan University, Ramat Gan, Israel

The arid and semi-arid Northern Negev in Israel has been degraded by thousands of years of overexploitation and improper land management. At 1990 the Israeli government encouraged improved land management based on privatization and savannization in part of these areas for rehabilitation and sustaining range use, Chiran area, northern Negev is one of them. We have performed a detailed analysis in this area since 2007 to study the effects of various management approaches. The effects of different factors such as tree species, planting method and land management on soil quality and watershed protection were analyzed. Our studies are indicating that various factors contribute to the impact of planted trees on the ecosystem. Planted Acacia victoriae increased the herbaceous biomass three fold underneath its canopy from the surrounded un-canopied area, achieving 1.2 Kg m^-2 in 2016. Acacia saliciana in contrast reduced the amount of herbaceous biomass two fold. Tree planting in contours reduced the annual herbaceous biomass three fold as compared to regular savannization (0.45 vs. 0.18 Kg m^-2 in 2010). Additional differences were found due to planting density, while A.victoriae woodland (250 – 400 trees per hectare) increased the herbaceous biomass three fold compared to conserved unplanted shrubland, and up to ten-fold compared to overgrazed, degraded shrubland. The woodland also enables development of species belonging mainly to the broad leaves group that are rare and even absent in the shrubland and savanna and modulates microclimate to the extent that agroforestry trees such as olive were successfully planted with minor initial irrigation only. More than that, scanning recent air-photos reveals that the A.victoriaeplantings stabilized the landscape by decreasing erosion phenomena as gullies and tors.  In conclusion, we present here an example of successful range lands restoration by adequate planting and management of appropriate tree species.