Hydroseeding for Restoring Degraded Semi-Arid Mediterranean Environments: A Review of Challenges.

Hydroseeding is a restoration technique commonly used in varied restoration projects. This literature review, encompassing about 100 published research papers from 1990 to 2020, revealed numerous limitations in a semi-arid Mediterranean environment. Challenges facing hydroseeding as a restoration tool in semi-arid Mediterranean environments were evaluated by analyzing different factors affecting ecological and technical levels. This issue was approached by sorting variables under either biotic or abiotic factors, further sub-dividing them under either natural-environmental or humaninfluenced factors. The review highlighted several constraints when applying hydroseeding techniques in a semi-arid Mediterranean environment: Slope steepness, slope aspect, high water runoff, low presence of water, mixing solutions used, and high cost for applying this technique are some of those constraints facing its success. Other shortcomings are related to the low success rate of commercial seed mixtures under harsh conditions, and their tendency to compete with native species. Moreover, the review provided recommendations to increase hydroseeding success by using varied techniques such as topsoil spreading, using native seeds, Mycorrhizal, or Rhizobium inoculation, and the use of nurse plants. Furthermore, environmental psychology approach was suggested as means to convey a better message and increase acceptability towards improved innovative suggestions.