Rangeland Ecology & Management

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UNPACKING SEED REGENERATION FOR RESTORATION IN AUSTRALIAN DRYLANDS: COMPLEX INTERACTIONS BETWEEN SPECIES, MOISTURE AVAILABILITY, AND SOIL TYPE
Author
Erickson, Todd E.
Dwyer, John M.
James, Jeremy J.
Kildisheva, Olga A.
Turner, Shane R.
Mu�oz-Rojas, Miriam
Merritt, David J.
Publisher
Society for Range Management
Publication Year
2018
Body

Plant regeneration in degraded landscapes is critical to temper the on-going impact of human disturbance. Yet for many species required for large-scale restoration in biodiverse drylands, initiating their establishment via seed is challenging. More often than not, clear protocols to consider and manage seed germination and establishment requirements are lacking. Important establishment barriers include narrow �environmental envelopes� that limit plant recruitment to rare periods of high, and consistent rainfall, and a reduced water holding capacity in soils impacted by human activities (e.g. reconstructed soil profiles). Cumulatively, these impediments prevent practitioners from reliably establishing a wide and representative array of native plants species from seeds. Seed-based restoration projects in the hot deserts of northwest Western Australia are no different. In the mining sector for instance, restoration seeding efforts that contained high-diversity seed mixes have seen complete germination failures, largely as a result of seed dormancy. Recent research shows that pre-sowing seed treatments can increase germination capacity and widen the germination envelope when specific cleaning methods and dormancy-alleviation treatments are applied. This presentation will highlight three key aspects of how we approach seed-based restoration that will improve the likelihood of plant establishment in dryland systems: (1) categorisation of the seed dormancy class that regulates germination; (2) identification of the underlying mechanisms that lead to the relief of dormancy and the development of reliable seed pre-treatments; and, (3) novel seed enhancement technologies (i.e. seeding priming, coating and pelleting) to maximise germination capacity under various seeding scenarios. Data from a large, purpose-built rain exclusion shelter will be used to demonstrate how we model seed germination, emergence, and early seedling survival across 20 different soil and rainfall scenarios.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Reno, NV