Abstract Detail

Ecology

Winkler, Daniel [1], Shackelford, Nancy [2], Paterno, Gustavo [3], Svejcar, Lauren [4], Leger, Elizabeth [5], Suding, Katharine [6].

Seeding rates and site aridity explain global patterns of dryland restoration success.

Effective restoration of degraded ecosystems is one of the greatest contemporary environmental challenges. Drylands are particularly difficult to restore, are home to more than a third of the global human population, a majority of which are socioeconomically marginalized; heightening the need to improve current restoration practices. Though dryland restoration research efforts are accelerating, no evaluation of these efforts at a global level exists. The Global Arid Zone Project (GAZP) brings together an international research collaboration and has developed a global database of dryland restoration research projects. To-date, the project characterizes restoration outcomes from 365 sites, encompassing 1,825 treatments and 594,065 observations of 671 plant species. We ask how broad-scale predictors affected restoration success (measured as the probability of target species establishment in treated areas), focusing on factors such as seed inputs, life history traits, abiotic conditions and site treatments. We also compared the motivation for restoration efforts world-wide, and described several stand-out examples of successful dryland restoration. Of the 11,816 observations in this database, the majority were either not at all successful (0% seedling establishment, 68% of the database) or completely successful (100% seedling establishment, 8% of the database). Restoration success varied among projects and sites, and random factors explained much of the variance in success. However, global patterns of dryland restoration success emerged. Seeding rate was a major predictor of success across projects, sites, and species. Site aridity also affected outcomes: predicted success rose from ca. 31% to 54% as site aridity index values decreased from 0.1 (highly arid) to 0.4 (less arid), then rose more gradually from ca. 54% to 64% between an index value of 0.4 to 0.7 (low aridity). Surprisingly, while invasion was a major motivation for restoration, weed control only increased the predicted probability of restoration success by 10%. Together, our results quantify some of the factors driving variable levels of restoration success around the globe for the very first time. The global GAZP network provides a new opportunity to learn from successes and failures and improve future restoration efforts.

Related Links:
Global Arid Zone Project (GAZP) website

1 - US Geological Survey, 2290 S West Resource Boulevard, Moab, UT, 84532, United States
2 - University of Victoria, School of Environmental Studies, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada
3 - Universidade Federal do Rio Grande do Norte, Departamento de Ecologia, Lagoa Nova, 59072–970, Natal, RN, Brazil
4 - Murdoch University, School of Veterinary and Life Sciences, Murdoch , WA, 6150 , Australia
5 - University of Nevada, Reno, Department of Biology, 1664 N. Virginia St., Reno, NV, 89557, USA
6 - University of Colorado Boulder, Ecology and Evolutionary Biology, Boulder, CO, 80303, USA

Keywords:
Restoration
Restoration ecology
drylands
seeding rates
plant functional groups
global database
Global Arid Zone Project
arid
semi-arid
management
aridity
invasive speices
native plants
plant establishment.

Presentation Type: Oral Paper
Session: ECO3, Ecology 3: Weeds, Exotic and Invasive Plants, Restoration Ecology, and Research Natural Areas
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 4:15 PM
Number: ECO3006
Abstract ID:388
Candidate for Awards:None