Forest health and habitat

This program area will investigate how harvesting is distributed through space and time. In addition, it will investigate how habitat features are retained across the landscape to support ongoing ecological function and habitat connectivity through a state forest.

Monitoring forest structure, health and regeneration

In order to cost effectively evaluate the effectiveness of the multi-scale landscape protections, two streams of monitoring will be implemented:

  • Operational monitoring: using existing harvest operations data collected by Forestry Corporation of NSW and a heterogeneity index derived from plot validation monitoring to give a real-time picture of forest heterogeneity and connectivity across the Coastal IFOA estate.
  • Validation monitoring: using remotely sensed data products supplemented by a ground-based forest and stocking plot network that validates the heterogeneity index used and provides ecological condition and regeneration response in post-harvest areas.

Monitoring impacts and recovery in fire affected forestry sites

During the summer of 2019/20, approximately 65 percent of Coastal IFOA state forests were affected by fire. The Coastal IFOA was not designed to moderate the environmental risks associated with harvesting in landscapes that have been severely impacted by fire.

The Environment Protection Authority (EPA) has issued additional site-specific conditions to the Forestry Corporation (FCNSW) that tailor protections for the specific circumstances of these burnt forests. As required by the conditions, FCNSW must work with the Commission to monitor the long-term impacts and recovery of burnt sites subject to forestry operations.

The Commission developed a plan with the FCNSW to monitor fire affected sites as part of the broader Coastal IFOA monitoring program. This plan was subject to expert review and approved by the NSW Forest Monitoring Steering Committee.

Monitoring key habitat features

This strategy investigates whether there is sufficient habitat features, in an appropriate configuration to ensure persistence of key fauna species. In addition, it will determine whether the Coastal IFOA conditions and protocols maintain sufficient resources through time to support ongoing viability of species. This will include three tasks:

  • a review of hollow use by key dependent fauna
  • hollow mortality and recruitment modelling
  • occupancy analysis of key habitat-dependent species.

Project: Hollow use review

The Program has engaged Associate Professor Ross Goldingay, Southern Cross University to review the scientific literature on managing, monitoring and researching hollow bearing trees in NSW forests. The review aimed to identify cost-effective approaches to monitor hollows and highlight research gaps. In addition, the review summarised the current knowledge on hollow use by key fauna species in harvested landscapes.

The review found that most studies have been short-term in nature. There is no clear consensus on the number of hollow trees that different hollow-dependent fauna required to maintain persistence. However, some individual arboreal mammals use a subset of their dens at a high frequency - for example, between 0.1 to 1 primary den trees per hectare based on home range sizes. When managing harvested forests for fauna persistence, it is important that target fauna can access hollows that are suitable in size and appropriately spatially distributed. Management should also account for hollow attrition.

The review outlined best methods to monitor hollow use by key species including the strengths and weaknesses of each. A significant research gap is to understand how den trees either persist or are lost in a harvested landscape, particularly following fire.

This work will inform species occupancy monitoring and modelling under the coastal IFOA monitoring program and broader Forest Monitoring and Improvement Program. The work will also inform hollow simulation modelling undertaken by the Australian National University as part of the program.

Project: Hollow mortality and recruitment modelling

Researchers at the Australian National University (ANU) have been engaged to improve hollow simulation modelling to predict the number of trees with hollows perpetuated under the current Coastal IFOA conditions. Professor Phil Gibbons, a national expert in tree hollows and modelling is overseeing the work. Ass. Professor Craig Nitschke, a leading forest modeller at the University of Melbourne is also advising on the work.

Working with modellers at the Forestry Corporation of NSW (FCNSW), the researchers have confirmed that the Forest Resource and Management Evaluation System (FRAMES) used by FCNSW is suitable for modelling the persistence and recruitment of hollow-bearing trees under a range of scenarios.

The ANU, FCNSW and the NSW Environment Protection Authority are collaborating to collect additional field data to improve model inputs and hollow simulation modelling. The team will also explore how recent LiDAR data collected across 250,000 hectares of state forests can be used to improve the modelling.

Tree hollow simulation modelling will help determine the effectiveness of the conditions and protocols of the Coastal IFOA at maintaining habitat resources over the long-term.

This work will significantly advance our knowledge on hollow-bearing trees, a critical habitat feature for many hollow-dependent fauna. A review by Ass. Professor Ross Goldingay, Southern Cross University commissioned under the CIFOA monitoring program found most studies on hollows have been short-term in nature. Further, there is no clear consensus on the number of hollow trees that different hollow-dependent fauna require to maintain persistence. When managing harvested forests for fauna persistence, it is important that target fauna can access hollows that are suitable in size and appropriately spatially distributed.

Monitoring landscape-scale trends

Spatial Vision and the NSW Department of Primary Industries Forest Science Unit will lead a consortium including RMIT University, University of New England, PF Olsen, University of NSW, NSW Forestry Corporation and the Department of Planning, Industry and Environment to deliver baselines, drivers and trends for forest health across all tenures, including Coastal IFOA state forests. Stephen Farrell and Dr Christine Stone will lead a team of over twenty eminent scientists.