Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Mojave Desert Ecosystem Recovery : Potency of Biotic and Abiotic Restoration Methods in Low Elevation Plant Communities

Auteur : Balogh Mary Amanda

Université de soutenance : University of Nevada, Las Vegas

Grade : Master of Science (MS) 2019

Résumé
The historic and current state of land in the Mojave Desert, including land managed by the National Park Service with fundamental goals of natural resource conservation and preservation, been severely degraded by a variety of anthropogenic disturbances. Due to increasingly sporadic and unpredictable precipitation patterns, land managers struggle to implement restoration projects with high success rates and are resource-limited for post-treatment monitoring. In this study, I examined success rates of biotic (outplanting, seeding) and abiotic (soil manipulation, vertical mulch) restoration treatments on various disturbance types in the creosote-bursage (Larrea tridentata-Ambrosia dumosa), blackbrush (Coleogyne ramosissima), and Joshua tree woodland (Yucca brevifolia) plant communities. Sites were surveyed in springs of 2018 and 2019 for annual and perennial plant species richness, percent cover, and perennial density to determine the effect size between unrestored, treatment, and reference (undisturbed) plot types. Sites were compared to determine what restoration treatment is most successful based on plant community, disturbance type, and the time since restoration or disturbance. Both biotic and abiotic treatments typically exhibited positive rather than negative restoration responses. Biotic treatments tended to have a more positive restoration success response than abiotic treatments. A large number of perennial effects were sensed while annual effects were often undetected. This study aims to provide evidence-based decision tools for land managers to choose restoration methods in an ecologically and economically effective manner.

Mots clés  : Creosote ; Mojave ; Outplanting ; Restoration Ecology ; Seeding

Présentation

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