We evaluated the effects of Acacia victoriae islets planted in 1993 in the Negev drylands on the productivity of the native herbaceous vegetation and soil fertility. Biomass, mineral-P, N and K and soil organic matter were measured from the planted and an adjacent unplanted area. The satellite-derived Normalized Difference Vegetation Index (NDVI) from MODIS was used to expand the timespan of the analysis after calibration with field data. Results showed an average improvement in biomass and rain use efficiency (RUE) of 40% compared to the unplanted area. Improvement was also observed in all nutrients concentrations and organic matter. Biomass was highly related to precipitation (R2=0.90, p<0.001), gradually declining from 2001 to 2009. Although declining with precipitation, RUE was maintained constantly higher in the planted area with respect to the unplanted lands even in dry years. The total biomass gained since plantation was estimated at 60gm-2yr-1 (i.e. 12tha-1) for a 20-year period. Our results suggest that planting woodland islets may significantly improve soil quality and biomass productivity of the native vegetation in drylands in a relatively short time.
Bibliographical noteFunding Information:
This research was partly supported by the Israel Ministry of Science and Project Wadi Attir and was carried out with collaboration with the Sustainability Laboratories, USA ( http://www.sustainabilitylabs.org/ ). We are grateful to the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) for providing the MODIS subset land products, and the Israel Meteorological Service (IMS) for providing the rainfall data. We finally thank to Dr. Roni Nehorai for assisting with the meteorological data, and to two anonymous reviewers that helped in improving this manuscript with their valuable comments.
- Acacia victoriae
- Rain use efficiency