years plusinage). occur inverylarge,oldtrees(100–150 and inparticular, largehollowsmayonly Hollows usuallytake alongtimetoform, ’. bearingtrees’or‘habitat termed ‘hollow on treespecies.Trees withhollowsare may forminearliergrowthstagesdepending of older, maturetoover-mature treesbut Such hollowsareusuallymorecharacteristic orbranchesofalivedeadtree. hollowsarecavitiesformedinthe What is a tree hollow? The importanceoftreehollows forarange habitat eitheronadailyor seasonalbasis. require hollowsasakey componentoftheir inthatthey termed ‘hollow-dependent’ shelter andnesting. Theseanimalsare which specificallyrequiresuchhollowsfor animals, includingmanythreatenedspecies, particularly importantforthosespeciesof However, treeswhich containhollowsare foraging, shelter, roostingandnesting. Trees provideresourcesforwildlife important? Why aretreehollows and GreaterGlider. as theSquirrelGlider, Yellow-bellied Glider Glossy BlackCockatoo and possums such the Powerful Owl, suchasthe than 10gramstolargeforestowlssuchas from smallinsectivorousbatsweighingless animal specieswhichutilisetreehollows Such diversitycatersforthewiderangeof – 30cmormore. to verylargewithentrancediametersof18 volume, fromsmallopeningsof2–6cm opening diameterandcavitydepth They mayvaryinsize,bothcavity insect orfungalattack. lightning strike orfireand/or duetotermite, formed asaresultofwindbreakage, Hollows orcavitiesintreesareusually Hollow bearing Lindenmayer 2002). birds, 32reptilesand16frogs(Gibbons& These animalsinclude46mammals,85 ofNSWthatarehollow-dependent. some 179animalspeciesoccurringin of animalspeciesiswelldocumentedwith Scientific Committee. Process (Final Determination)bytheNSW has beenlistedasaKey Threatening drastically reduced.Theloss oftreehollows die outorareremoved,animaldiversityis For example, whereoldertrees withhollows animals. cases, mayresultinlocalextinction ofthese diversity andabundanceand,insome animalspecies loss ofhollow-dependent diversity ofhollowscanleadtoasignificant Any decreaseintheavailabilityandnatural across thelandscape. mature toovertrees,withhollows It isimportantthereforetomaintainolder requirements ofalltheseanimals. available tocaterforthespecialecological to ensurethatadiversityofhollowsis sizes, depths,volumesandpositionshelps The occurrenceofanaturalrangehollow survival. limiting factortotheiron-going bearing treesacrossthelandscapeisakey For thesespecies,theavailabilityofhollow- Musk Lorikeetatnesthollow

trees Roly Paine Roly

Private Native - Advisory NOTE 1 Photographs: John Turbill Hollow-bearing tree definition

“A hollow-bearing tree is a dominant or co-dominant living tree, where the trunk or limbs contain hollows, holes or cavities. Such hollows may not always be visible from the ground but may be apparent from the presence of deformities such as protuberances of broken limbs, or where it is apparent the head of the tree has broken off.”

Hollows may occur in tree branches as well as the trunk. Hollows also include fire scars in the butt of trees and fissures or cracks in the branches or the main trunk.

Retention of hollow References and Further bearing trees Reading The Private Native Forestry Code of • Gibbons, P & Lindenmayer, D (2002), Practice requires the retention and Tree Hollows and Wildlife Conservation in protection of a minimum number of hollow Australia, CSIRO. bearing trees per hectare dependant on the • For a list of hollow-dependent fauna Broad Type. Retained trees should species refer to Advisory Note 8 “Old be a live, dominant or co-dominant (i.e. Growth Forests on Private Land”. generally trees with the largest diameter) tree with good crown development and • DECC: www.environment.nsw.gov.au minimal butt damage (i.e. fire scarring). • NSW Scientific Committee Preliminary Retained trees should, where possible, Determination - Loss of hollow-bearing represent the range of tree species that trees as key threatening process. occur in the stand in the mature and late mature growth stage. They should also be • www.nationalparks.nsw.gov.au/npws. evenly distributed throughout the area of nsf/content/tree_hollows_factsheet. harvesting operations within the net area. Retained hollow bearing trees should be protected to the greatest extent practicable DECC from butt damage from machinery and directional falling techniques should be used to minimise damage from tree harvesting to the crown and branches. Additionally, it is advisable to protect retained trees from any post harvest fire damage by ensuring that no logging debris is allowed to accumulate around the trunk and damage to the trees surface roots should be minimised by avoiding soil compaction and surface ripping by machinery. The field marking of hollow bearing trees will help ensure protection of these trees over on-going silvicultural and harvesting Hollow bearing tree - Blackbutt (Eucalyptus pilularis) activities.

Department of Environment and Climate Change 1300 361 967 | environment.nsw.gov.au | [email protected] | August 2007 ISBN 978 1 74122 513 6 DECC 2007/353