Variable Retention and Biodiversity: Forestry Tasmania's Goals And

Variable retention and biodiversity: Forestry Tasmania’s goals and monitoring program

Sue Baker, Simon Grove, Steve Read, Tim Wardlaw Talk Outline

• Operational variable retention (VR) – FT’s program –Goals – Guidelines • Biodiversity studies in the Warra SST • Biodiversity assessments in operational VR • Landscape considerations Operational implementation of VR in Tasmania

• 11 coupes totalling 408 ha harvested and regenerated (as at June 2007) • Harvesting completed or in progress for another 13 coupes totalling 528 ha • Adaptive management through regular peer review of the conduct of VR operations Forestry Tasmania’s goals for VR

• More closely emulate natural ecological processes in managed tall, wet eucalypt forest

– by retaining late-successional species and structures (biological legacies) for at least a full rotation. • Maintain a forest edge influence over the majority of the felled area

• Achieve adequate productive regeneration of both eucalypts and other species

• Ensure safety of forest operations Forestry Tasmania’s guidelines for VR

1. Majority of felled area should be within one tree height of retained forest 2. Retained areas can be free-standing (island aggregates), OR contiguous with standing forest outside of the coupe (edge aggregates) 3. Aggregates should be: • at least one hectare in size • anchored to specific locations of ecological value • encompass the range of vegetation types present 4. Hazardous trees in aggregates and edges should be sufficiently buffered to ensure they do not pose a danger Guidelines for VR (cont’d)

5. Coupes should look different from clearfelled coupes - avoid large gaps and long view lines 6. Coupe layout and fuel preparation to allow safe and effective burning: • receptive seedbed over >2/3 of the felled area • coupe should meet seedling stocking standard (65% 16 m² stocking) at 3 years 7. Firebreaks and access tracks: • area should be minimised • preparation should not unduly compact soils, damage soil profiles, or otherwise compromise ecological values Operational monitoring of biodiversity: developing an approach

• Answer key questions: – how well do retained patches perform in providing viable habitat to maintain late-successional species within coupes? – do increases in mature forest influence provided by VR help to maintain late successional processes in production forestry landscapes? • Practical and affordable to implement • Informed by experiences and findings from SST and elsewhere Warra Silvicultural Systems Trial (SST)

Aim: to compare alternative methods to clearfelling for harvesting oldgrowth wet eucalypt forest

DRN

CBS CBS CON LEGEND ARN DRN CON = Control CBS = Clearfall, burn & sow (with islands) CON ARN DRN = 10% dispersed retention ARN = Aggregated retention Warra SST - Biodiversity studies

Aim: Document responses of a range of life- forms to silvicultural treatments in wet E. obliqua forest Methods: Before - after - control - impact design Two replicates per treatment Biodiversity surveys done pre-logging, 1- year and 3-years post-logging Life-forms: Ground beetles Birds Vascular plants Bryophytes Lichens Warra SST - Biodiversity studies