f’ores;;;ology Management Forest Ecology and Management
72 ( 1995 ) 13 1- 149
Effects of partial logging systemson bird assemblagesin Tasmania Robert J. Taylor*, Murray E. Haseler Forest Practices Unit, Forestry Tasmania, 30 Patrick Street, Hobart, Tas. 7000, Australia Accepted 11 August 1994
Abstract The effects on bird assemblages of several partial logging systems were examined in dry eucalypt forests in Tasmania. Densities and species composition of birds in partially logged areas were compared with those in adjacent mature forest, with clearfelled areas sometimes also being sampled. In the tirst study, the effects of advanced growth retention logging, which involves retaining all young trees with good growth potential, were compared with those of 17-year-old regeneration resulting from clear-felling. Densities of most bird species were lower in areas of advanced growth retention than in mature forest but there was no evidence of any species being excluded from the advanced growth retention. The relative use of the three forest types varied over the seasons. The differences were most marked in spring and winter. Two species (superb fairywren and brown thornbill) were most abundant in areas of advanced growth retention in autumn. Two species (strong-billed honeyeater and flame robin) that were common in mature forest and advanced growth retention were not recorded in the clearfell regeneration. In the second study, the effects of overstorey removal logging, which involves the removal of older trees and the retention of an even-aged stratum of younger trees, was examined with 3-year-old clearfell also sampled. Most species were more abundant in mature forest than in overstorey removal with canopy and mid-layer birds being more adversely affected than birds which predominately utilised the lower layers or the ground. One species, the superb fairy-wren, appeared to be advantaged by logging. Species diversity and abundance of birds were much lower in 3-year-old clearfell than in both mature forest and overstorey removal. In the third study, the effects of shelterwood logging, which involves the retention of 30-50% of the canopy to provide protection for young regeneration from climatic extremes, were examined. Many species were more abundant in mature forest than in shelterwood with the differences being most pronounced for canopy and mid-layer birds. In winter one species, black-headed honeyeater, was more abundant in shelterwood than in mature forest. Satin flycatchers appeared to be unable to utilise the logged forest. Partial logging is increasingly being used in preference to clearfelling in the dry forests in Tasmania. Partial logging systems have a much lower impact on birds than does cleat-felling. Thus, retention of older trees can ameliorate the impacts of logging. Densities of birds are reduced after partial logging but numbers of species present are comparable with mature forest. A few species increase in abundance after partial logging. However, on some sites retention of a large component of the mature canopy will still lead to the disappearance of one or two species. Keywords: Logging; Partial logging system;Bird assemblage;Eucalyptus; Sclerophyll forest
*Corresponding
author.
0378-l 127/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved .WIIO378-1127(94)03470-2
132
R.J. Taylor, M.E. Haseler /Forest Ecology and Management
1. Introduction
Prior to the 1960sTasmania’seucalyptforests wereselectivelycut-over with little deliberateattempt to ensureregeneration(Wilkinson, 1994). The clearfell, burn and sow silvicultural system was developed in the wet sclerophyll forests (Gilbert, 1959;Gilbert and Cunningham, 1972). This treatment producesa densestand of evenagedregrowthwith few treesremaining from the original stand. The clearfell technique was applied to the treatment of drier forestscommencing in the 1970swith the advent of the woodchip industry.In the last decadetherehasbeena trend towards the development and use of a more diverserangeof silvicultural techniqueswhich are more closely tailored to suit individual forest types. Most studieson the effectsof logging on birds in Australia have examined areassubjected to clearfelling or similar systems (Loyn, 1980; Pattemore, 1980; Recher et al., 1980; Green, 1982;Loyn, 1985;Dickinson et al., 1986). All of thesestudieshave found a dramatic decreasein the abundanceand diversity of speciesafter logging and regenerationburning in both wet and dry forests.As regenerationproceedsstructural changesin the vegetationoccur and are associated with successionin the avifauna. There is a general trend for species diversity and abundanceof birds to increasewith forest age (Loyn, 1993). The presentstudy examinesthe effectson bird assemblagesof a rangeof partial loggingsystems which have replaced the use of clearfelling in many of the dry and damp sclerophyll forestsin Tasmania. Some sampling of regeneration resulting from clearfelling was also undertaken as a comparison with alternative treatments.
72 (199.5) 13 I- 149
ther information is provided in McCormick and Cunningham ( 1989), Battaglia ( 1990) and McCormick ( 1991). Fig. 1 illustrates the structure of standsbeforeand after treatment. 2.1. Clearfell
This involves removal of all trees. It is normally applied to mature standswhich are singleagedand to wet forestswith a denseunderstorey wherebare ground (usually achieved-by high intensity slashburns) is necessaryfor seedlingestablishment. In 1990- 1992only 27% of treated dry forest was clearfelled but 93% of wet forest was treated by this method (Wilkinson, 1994). Dry forests often exhibit a multi-age structure and this allows the application of more diverse silvicultural treatments. These dry forests can also be regeneratednaturally from advanced growth or from seedshedduring logging. 2.2. Seedtreeretention Sevento 15 well-spacedtrees per hectareare retained. This technique is applied to forests where retention of seedtreesis more cost effective than artificia1 sowing and to open forests wherea continuing seedsourcewill maxitiise regenerationopportunities on harshsites. 2.3. Advancedgrowth retention This is applied to forests with a multi-aged structure. All young treeswith good growth potential are retained with a multi-aged structure beingmaintained. 2.4. Overstoreyremoval
2. !3ikicultural
systems
The silvicultural treatments applied to the areasexamined during this study are described below and somebackgroundgiven on the forest types to which thesemethods are applied. Fur-
This is applied to two-agedstands co-mprised of a stratum of older trees over an even-agedstratum of youngertrees.The treatment involves removal of the older ageclasswhich releasesthe regrowthfrom competition with the o&r trees.
R.J. Taylor, M.E. Haseler /Forest Ecology and Management
133
72 (1995) 131-149
Post-logging
Pre-logging SEEDTREE
Pre-loeeine .
SHELTERWOOD
Post-logging
Pre-logging ADVANCED
GROWTH
Pre-loming Fig. 1. Silvicultural
-
RETENTION
I
treatments examined in this study. Diagrams show the forest before and after logging for each treatment.
2.5. Shelter-wood
Treeswith goodcrownsareretainedsothat 3050% of the original canopy cover remains. This systemis utilised on sites (particularly high altitude areas) where new regeneration requires some initial protection from climatic extremes such as frost. The retained overstorey is removed when the regenerationis greaterthan 1.5 m in height.
The natural variation in structureof many dry forests often results in a mosaic of silvicultural treatments with a combination of techniques sometimesbeing applied in the one coupe (cutting unit). The selection of silvicultural technique is largely determined by the quantity of youngtreesavailable for retention.
134
R.J. Taylor, M.E. Haseler / Forest Ecology and Management
3. Study areas
Four sites were chosenso as to sample areas subjectedto a rangeof silvicultural treatments. ThesewereTooms (clearfell and a combination of advanced growth and seedtree retention), Bradys (clearfell and overstoreyremoval), Echo ( shelterwood)and Clarence( shelterwood) . The geologicalsubstrateat all sites was dolerite. At each site loggedareasand surrounding mature forestwith similar vegetationwere sampled. 3.1. Tooms
This site was at an altitude of 650 m on the ranges in eastern Tasmania (42 ‘09’S 147”53’E). Three logging coupes were examined. Two of thesewere treated using a combination of advancedgrowth retention and seedtree retention and one wasclearfelled.The forest on the site had previously been subject to scattered selective logging. The distribution of different ageclassesof eucalypt was variable. After application of the retention logging treatments the area was a mosaic of small patchesof clearfell (where there was previously an even-aged mature stand), even-agedregrowth (wherethere was previously a two-agedstand) and unlogged areas(wherethere wereyoungtreeswith no mature trees present or on knolls which were too rocky to log ) . The vegetationon the site was mostly shrubby Eucalyptus delegatensis forest with Eucalyptus amygdalina as a minor species.Two major understorey associations were present. In one of thesethe shrub layer consistedof small ( l-3 m ) Acacia dealbata with Lomatia tinctoria prominent in the ground layer. In the other the shrub layer was dominated by 2-4 m Banksia marginata with a ground cover of Lomandra longifolia and scatteredpatchesof Cyathodes glauca. Two other understorey types were present but only covereda small area.Somepoorly drained areas were presentwith a denseundergrowth of Leptospermum lanigerum, Gahnia grandis and Lepidosperma concavum.
The regenerationin the clearfell coupewas 17 yearsold and around 3-6 m tall at the time of
72 (1995) 131-149
sampling. This coupe had a north westerly to westerlyaspectand containedboth undergrowth types, althoughthe Banksia type predominated. Someswampyundergrowthwasalsopresent.The coupe was burnt using a hot regenerationburn and was artificially sown. One of the advanced growth retention coupeswas dominated by the Acacia understoreytype. It was logged 4 years prior to the study and was not burnt after iogging. The coupe was 40 ha and located on a southeastfacing slopewith the rocky crestof the hill not logged.The other advancedgrowth retention coupewas 306 ha and included most of a plateau. Both major undergrowth types were present.Somerocky knolls in this coupewerenot logged.The areawas loggedthe year before the studyand cool burnt to reducefuel loads.An area of 30 ha of the coupe was again burnt by a fire which startedfrom a smoulderingbark heapseveral months beforethe start of the study. Most of this twice-burntareawasnot sampled.A swampy area was present which was only burnt by the secondfire. The mature forest sampled was located around the edgeof the plateau containing the loggedarea and betweenthis coupe and the clearfelledarea. 3.2. Bradys
This site was located in central Tasmania (42”18’S, 146”37’E) to the southwest of Dee Lagoonat an altitude of 700 m on gentleeastand west facing slopes.Two loggingtreatments were examined, clearfell and overstoreyremoval. The clearfell coupe was 140 ha. It had been artificially sown but not burnt. It carried 3-year-old regenerationat the time of the study. The other coupe had had the mature treesremoved and a younger 20-year-oldpole stand ( 10 m tall) retained. This coupehad beenloggedthe year before the study. The coupe was crisscrossedwith snig tracks but many undisturbed patches of shrubbyundergrowthremained around retained eucalypts. The vegetation community present was shrubby E. delegatensis forest with Eucalyptus obliqua as a minor specieson the ri s and Eucalyptus dalrympleana as a minor species-onthe
R.J. Taylor, M.E. Haseler /Forest Ecologyand~Uanagement
lower slope. The understorey of the site was dominated by a 3-5 m tall shrub layer of Acacia verniciflua and/or Bedfordia salicina. Acacia verniciJlua dominated on the ridgesand Bedfordia salicina generallypredominatedon the slopes. The groundlayer was usually sparsedue to shading by the shrub layer. Common speciesin the ground layer included Cyathodes parvifolia, Lomatia tinctoria and Pultenaea juniperina. The clearfell coupe was covered with regenerating Bedfordia salicina and Pteridium esculentum. 3.3. Echo
This site wassituated on the slopesadjacentto the northeasternside of Dee Lagoon in central Tasmania (42” 14’S, 146”35’E) at an altitude of 700 m. The midslope was sampled.The vegetation here was shrubby E. dalrympleana with E. delegatensis present as a minor species. The coupesampledwas 100ha in areaand waslogged accordingto shelterwoodprescriptions.The canopy had beenreducedby around 65%. The area was logged in 1986, nearly 5 years before the presentstudy and wassubjectto a hot fuel reduction burn 3 years after the logging. In the unlogged area a very scatteredtall (over 1.5 m) shrub layer of A. dealbata and eucalypt saplings waspresent.The low shrublayer was dominated by speciessuchas C. parvifolia, Pultenea juniperina, Lomatia tinctoria and Pteridium esculentum and wasmore openand shorterin the loggedarea than in the unloggedarea. 3.4. Clarence
This site was in hilly terrain 17 km northwest of the Echo site (42”07’S, 146”26’E) at an altitude of 800 m. The vegetation present was shrubby E. delegatensis forest with E. dalrympleana as a minor species.The understoreywas similar to that at the Echo site but the tall shrub layer was better developed(probably owing to a longerfire-freeperiod) and containedHakea lissosperma as well as A. dealbata and eucalypts. Three coupeswere sampled, all subject to shelterwood prescriptions. One was logged 2 years beforebeingsampled,was 100ha in areaand was
72 (1995) 131-149
135
subject to a top disposal burn. The other two areaswere smaller ( 18 and 20 ha), were logged 1 and 2 yearsbeforebeing sampledand werenot subject to a post-loggingbum. The canopy on thesecoupeshad beenreducedby around 75%. 4. Methods
Two methods for surveying birds were employed, area searchesand transectcounts. Area searchesshould provide an accurateassessment of density for relatively sedentaryspeciesoccurring at higher densitiesand should detectinconspicuous species(Loyn, 1986). However, they are probably of limited value for specieswhich occurat low densitiesand rangewidely in flocks, as is often the casein the non-breedingseason. Transectcounts provide a better surveymethod for the latter species (Recher, 1988). Area searcheswereundertakenin permanentlymarked 100 m2 plots. Surveys were undertaken in the morning commencing when there was sufficient light. The exacttimes of surveysvaried depending on the seasonand weather conditions (e.g. the occurrenceof heavycloud coveror fog led to a later start). A maximum of four plots were searchedper morning with at least 20 min spent in eachplot. Wherever possible,pairs of logged and mature forest plots with the samevegetation type weresearchedon the samemorning to minimise the influence of weather on the comparisonof treatments.Eachmarkedplot wassearched twice over the course of a sampling period. At Tooms a total of ten plot searcheswere undertaken in the partially loggedareaand ten in the mature forest.At Bradys,eightplot searcheswere undertaken in the two treatments and at both Echoand Clarencefour. The transectcountswere commencedimmediately after the areasearches were completed and continued until the end of the morning activity period. The path taken varied eachday with a recordbeing kept of the distancetravelled in eachvegetationand treatment type. The approximatedistanceof birds from the transectline and the total numbersseenor heard were recorded. A record was also kept of the sighting of bird speciesfor each lo- 12 min time
136
R.J. Taylor, M.E. Haseler / Forest Ecology and Management
interval while undertaking the transects. The numbers of individuals seen for most species were insufficient to enable detailed sightability curves to be plotted. Thus calculation of densities was not possible for transects. Instead the absolutecounts were used.Examination of plots of numbers seenversus distance indicated that birds could be seenovergreaterdistancesin areas logged using partial logging systems compared with mature forest. Thus, the transect data may be conservative in relation to showing declines in species associated with logging. Transect lengthsare given in Table 1. Field work was undertaken betweenNovember 1991and July 1992.Sampling at Tooms was undertaken in eachseasonbut only in spring or summer and winter at other areas.Dates of sampling were as follows: Tooms, 7- 17 November, 22-28 February, 8-24 April and 29 June-5 July; Bradys, 21-27 November and 9-25 July; Echo and Clarence,5- 10December and 2-7 June. Usageof common names of the birds follows that of Blakerset al. ( 1984). Scientific namesare given in Appendix 1. 4.I. Data analysis Where numbers were sufficient, data for individual specieswere tested for any effects of logging. Partial logging systemsaffect structural attributes of the forest rather than the composition of their vascularflora (Duncan, 1981) . Bird specieswerethus groupedinto three guilds basedon Table 1 Transect length (km) in each treatment at each site Site
Season
Clearfell
Partially logged
Mature forest
Tooms
Spring Summer Autumn Winter
2.00 1.oo 1.40 1.65
7.10 7.05 6.90 8.30
4.75 7.85 8.35 7.30
Bradys
Spring Winter
5.60
6.30 7.20
3.10 6.70
Echo + Clarence
Summer Winter
-
8.00 9.25
8.85 11.50
72 (1995)
/31-
149
the height at which most of their foraging was undertaken, i.e. canopy, sub-canopy and tafl shrubs (referredto as mid-layer) and low shrubs and ground (referredto asground). The birds in eachof thesecategoriesare asfollows: ( 1) canopy:black-facedcuckoo-shrike,yellow wattlebird, black-headed honeyeater, strongbilled honeyeater, spotted pardalote, straited pardalote,shining bronze-cuckoo; (2) mid-layer: grey shrike-thrush,greyfantail, brown thornbill, Tasmanian thornbill, yellowtailed black-cockatoo, golden whistler, yellowthroated honeyeater,crescenthoneyeater,New Holland honeyeater, eastern spinebill, olive whistler, silvereye,satin flycatcher; ( 3) ground: dusky robin, flame robin, pink robin, scarlet robin, superb fairy-wren, whitebrowed scrubwren, White’s thrush, common bronzewing, grey currawong, kookaburra, fantailed cuckoo, pallid cuckoo, wedge-tailedeagle, greybutcherbird, black currawong,forest raven. Green rosellas were not included in these height guilds becauseof their high use of both ground and canopyhabitats.Their numberswere often great enough to allow significance testing on their own. The numbers of birds in these guilds, alongwith total numbersand numbers of species,were also examined for any effects of logging. Introduced specieswere not included in the analysis.Introduced specieswere only sightedat Bradys; one blackbird in mature forest and two goldfinchesin overstoreyremoval in spring and in winter a large flock of approximately 300 goldfinchesin the clearfell. For the data collectedfrom areasearches,differencesbetweenloggedand mature forest were testedusing the Wilcoxon matched-pairssignedranks test. The plots werepaired into loggedand mature forest pairs of the same vegetationtype sampled on days with similar weather patterns. Only specieswhich occurred in at least half of the pairs of plots were included in the analysis. This wasdoneto avoid biasresultingfrom chance situations such as a large flock being recorded from a singleplot. For the transectcounts numbersseenin loggedand mature forest were compared using chi-squaretests. Only specieswith
R.J. Taylor, M.E. Haseler / Forest EcologyandManagement
more than ten individuals in at least one of the treatmentsand with expectedfrequenciesgreater than five wereincluded in the analysis.Expected frequencieswere calculated on the basis of the length of the transectwalked in a treatment with the numbersof birds in loggedand mature forest assumedto be equal. Probabilities of less than 0.05 were accepted as indicating significant differences. For the areasearchesplots with similar undergrowth were paired when comparing the different treatments. For the transects the distance walked in the different undergrowthtypeson an
72 (1995) 131-149
137
area differed slightly between treatments. The differencesobtained in the bird composition between treatments for the transects were examined to seewhetherany of thesedifferencescould be attributable to different sampling intensities of the undergrowth types. Two sites (Echo and Clarence) that were loggedaccordingto shelterwood prescriptions were examined. These sites differed in the dominant eucalyptpresentandthe abundanceof taller shrubs. The plot data were amenableto analysiswith both areascombined as shelter-woodand mature forest plots were paired at eacharea.The transectdata for the two
Table 2 Comparison of bird populations in advanced growth retention and mature forest at Tooms using area searches. Only those species or categories with sufficient numbers were included in the analysis (see Methods). Green rosellas were not included in a foraging height guild (see Methods). Abundance values are numbers per ten plots Season
Species (or category)
Abundance Advanced retention
Mature forest
Significance of difference
Spring
Green rosella Superb fairy-wren Brown thombill White-browed scrubwren Yellow wattlebird Eastern spinebill Canopy birds Mid-layer birds Ground birds Total numbers Number of species per plot
2 0 9 0 6 1 12 23 14 51 2.9
7 9 11 11 9 9 34 25 23 92 5.4
NS < 0.05 NS co.05 NS <0.05 NS NS NS NS <0.5
Summer
Canopy birds Mid-layer birds Ground birds Total numbers Number of species per plot
15a 15 8 38 1.1
5 17 19 45 2.7
NS NS NS NS < 0.05
Autumn
Scarlet robin Canopy birds Mid-layer birds Ground birds Total numbers Number of species per plot
6 27 20 35 92 2.8
1 3 13 17 44 1.7
NS NS NS NS NS NS
Winter
Canopy birds Mid-layer birds Ground birds Total numbers Number of species per plot
9 16 5 34 1.6
19 24 17 60 2.2
NS NS NS NS NS
aAll one species from one plot.
138
R.J. Taylor, M.E. Haseler /Forest Ecology and Management
72 (1995) 131-149
Table 3 Comparison of bird populations in 17-year-old regeneration resulting from clearfelling, advanced growth retention and mature forest at Tooms using transect counts. Abundance values are numbers per kilometre. Only those species with sufftcient numbers were included in the analysis (see Methods). The dashed line in the significance of difference colilmns indicates insufficient numbers for analysis Season
Species (or category )
Abundance Clearfell
Spring
Summer
Autumn
Significance ofdifference Advanced retention
Mature forest
Green rosdla Grey fantail Brown thombill Yellow wattlebird Strong-billed honeyeater Yellow-throated honeyeater Crescent honeyeater Eastern spinebill Striated pardalote Black currawong Canopy birds Mid-layer birds Ground birds Total numbers
2.5 0.5 6.0 1.5 0 4.0 0 3.5 2 2.5 5.0 16.0 8.5 32.0
1.5 0.7 1.3 3.7 0.4 1.4 0.4 2.3 2.4 2.4 8.9 7.6 6.3 24.4
3.6 4.2 5.3 4.6 2.1 7.3 4.6 4.4 9.5 3.6 21.9 23.4 11.6 60.4
Green rosella Brown thombill Yellow wattlebird Strong-billed honeyeater Yellow-throated honeyeater Eastern spinebill Spotted pardalote Striated pardalote Crescent honeyeater Scarlet robin Canopy birds Mid-layer birds Ground birds Total numbers
4.0 2.0 8.0 0 15.0 8.0 3.0 0 0 I.0 15.0 39.0 17.0 75.0
0.9 2.6 3.5 0.7 2.7 1.6 0.4 0 0.9 0.7 6.0 9.6 3.7 20.1
1.9 5.9 4.1 2.4 3.4 2.5 !.4 I.S I.7 1.4 10.8 16.3 4.5 33.5
Green rosella Scarlet robin Superb fairy-wren Brown thombill Yellow wattlebird Strong-billed honeyeater Black-headed honeyeater Yellow-throated honeyeater Crescent honeyeater New Holland honeyeater Eastern spinebill Spotted pardalote White-browed scrubwren Canopy birds Mid-layer birds Ground birds Total numbers
11.4 1.4 0 2.9 5.7 0 8.6 8.6 49.3 0 6.4 2.1 0 16.4 72.9 5.7 106.4
3.6 1.6 2.3 4.6 2.3 2.0 8.0 3.3 6.7 0.1 3.2 0.9 1.4 13.8 19.4 8.7 45.5
2.h 2.5 I.0 2.0 4.2 3.1 16.0 5.0 11.1 3.8 4.2 1.6 0.8 25.3 29.5 6.6 64.0
CxAr
.NS -
NS NS
CxM NS < 0.05 NS < 0.05 NS co.01 NS ‘co.01 NS
..< 0.00 1 < 0.00 1
NS < 0.00 1 < 0.001
NS
NS
NS
co.05 < 0.05
NS
NS <0.001 NS
---_ArxM < 0.05 CO.05
R.J. Taylor, M.E. Haseler /Forest Ecology and Management
Season
Species (or category)
Abundance Cleat-fell
Winter
Green rosella Suberb fairy-wren Tasmanian thornbill Yellow wattlebird Strong-billed honeyeater Black-headed honeyeater Yellow-throated honeyeater Crescent honeyeater New Holland honeyeater Eastern spinebill Brown thornbill Laughing kookaburra Spotted paradalote Canopy birds Mid-layer birds Ground birds Total numbers
3.0 4.8 1.2 0 0 0 0.6 0.6 2.4 3.6 3.0 0 0.6 0.6 11.5 4.8 20.0
72 (1995) 131-149
139
Significance of difference Advanced retention
Mature forest
CxAr
CxM
ArxM
1.8 1.0 1.6 1.1 0.6 1.3 1.1 3.3 2.2 1.1 0 1.7 1.2 4.2 11.8 5.2 23.0
5.3 5.8 2.1 3.8 5.2 11.5 4.2 5.8 2.1 1.6 1.5 0.1 1.9 22.5 21.6 9.3 58.8
co.05 -
NS NS _. -. CO.01
areas were first analysed separately.The bird faunasand differencesbetweentreatmentswere similar and so the data for the two areaswere combined. Occurrencesof bird speciesin eachtreatment for eachareaaregiven in Appendix 1. 5. Results 5.1.Advancedgrowth retention In springall significant differencesbetweenthe abundanceof species,numbers of speciesper plot, height guilds and total numbers of individuals showeda consistenttrend of greaternumbers in the mature forest compared with advanced growth retention for both area searches (Table 2 ) and transects(Table 3). However,the total numbers of speciesrecordedin mature forest and advancedgrowth retention were similar (Figs. 2 and 3). For the 17-year-oldclearfell coupe numbers were generallynot significantly different from the advanced growth retention with the exception of the number of mid-layer birds which wasgreaterin the clearfell. Numbers of speciesrecorded in clearfell were, however,
I <0.05 NS NS NS
lower than in both mature forest and advanced growth retention (Fig. 3) . In summer the numbersof birds sightedoverall were lower than in spring. Numbers of individuals for speciesand guilds were again sometimes higher in mature forest than in advanced growthretention but the magnitudeof the differenceswas reduced in summer compared with spring (Tables2 and 3 ) . The numbersof species observedin plots in mature forest were greater than in advancedgrowth retention (Fig. 2) but speciestotals weresimilar for transects(Fig. 3) . Numbers in the clearfell, particularly for the honeyeaters,weregreaterthan in either the mature forest or the advancedgrowth retention (Table 3). However, sampling of the clearfell was limited and comparisonsmay havebeeninfluenced by the predominanceof Banksiaundergrowthin the clearfell. In autumn the data from area searchesand transectsweresomewhatcontradictorywith plots showing greaternumbers of birds in advanced growth retention (Table 2) and transectsshowing greaternumbersin mature forest (Table 3 ) . However, none of the differencesfrom the area searchesweresignificant.With the transects,two species(superbfairy-wren,brown thornbill) had
R.J. Taylor, h4.E. Haseler /Forest Ecology and Management
o’,,
,
I,,
,
,
12345678
01,
I, 12345678
I,,
,
,
,
72 (1995) 131-149
,I
9
10
, 9
,’ 10
76,
0
1
0
5
5
10
15
20
25
30
1
I
I
I
,
f
IO
15
20
25
30
35
30 I
oJ,,
,
12
3
,
4
,
5
u,,
6
7
8
,
9
7
,I 10
0
20
4.0
25,
50 L
iii w;Fi a&, 12
I
,
I
I
I
,
I
3
4
5
6
7
8
t
9
I’
10
No. of Plots Fig. 2. Cumulative number of bird species recorded from area searches at Tooms for mature forest and advanced growth retention.
significantly higher numbersin advancedgrowth retention and four of the honeyeatersplus numbers of canopy, mid-layer and total individuals weresignificantly greaterin mature forest.Numbers of specieswere slightly greaterin advanced growth retention than in mature forest (Figs. 2 and 3) . Total numbers,mid-layer birds, crescent honeyeaters,yellow-throated honeyeaters and greenrosellaswere significantly greaterin clearfell than in mature forest. For an equivalent
-
Advanced
--+--
Clearfell
retention
0
50
Nb9 of ~~,~3~~~~~~~ Fig. 3. Cumulative number of bird species recorded from transects at Tooms for mature forest, advanced growth retention and 17-year-old clearfell.
sampling intensity, speciesnumbers in clearfell were similar to that of advancedgrowth retention but slightly greater than in mature forest (Fig. 3). In winter numbers in mature forest wereconsistently greaterthan in advancedgro%vthr&ention (Tables 2 and 3). Numbers of specieswere similar in mature forest and adv~d-~~ retention (Figs. 2 and 3) . Numbers of ail individ-
R.J. Taylor, M.E. Haveler / Forest Ecology and Management
72 (1995) 131-149
141
Table 4 Numbers of species recorded in area searches and on transects in partially logged and mature forest over all seasons for each study area. Logging technique utilised at Tooms was advanced growth retention, at Bradys overstorey removal and at Echo and Clarence sheltetwood. ‘Common’ species are those for which greater than five individuals were sighted (over all seasons and both census methods) Study area
Tooms Bradys Echo/ Clarence
Species
All common All common All common
Area searches
Transect
Partial logged
Mature forest
Clearfell
Partial logged
Mature forest
23 23 21 19 14 14
20 20 21 18 17 16
24 22
32 28 28 24 25 23
31 28 30 24 28 23
-
Table 5 Comparison of bird populations in overstorey removal and mature forest at Bradys using area searches. Values are numbers per eight plots Season
Species (or category)
Abundance
Significance of difference
Overstorey removal
Mature forest
Spring
Yellow wattlebird Striated pardalote Superb fairy-wren Grey fantail Brown thombill Tasmanian thombill Flame robin White-browed scrubwren Black currawong Canopy birds Mid-layer birds Ground birds Total numbers Number of species per plot
1 0 20 6 16 4 6 13 2 12 33 46 94 6.3
11 7 1 16 7 11 7 14 3 27 47 26 101 7.0
<0.05 < 0.05 NS (~0.06) 10.05 NS NS NS NS NS NS NS NS NS NS
Winter
Crescent honeyeater Yellow wattlebird Black-heated honeyeater Yellow-throated honeyeater Green rosella White-browed scrubwren Strong-billed honeyeater Canopy birds Mid-layer birds Ground birds Total numbers Number of species pet plot
8 0 19 2 6 3 7 27 24 16 73 3.1
8 5 32 6 5 2 10 47 21 24 97 3.9
NS NS (=0.06) NS NS NS NS NS NS NS NS NS NS
142
R. J. Taylor, M. E. Haseler / Forest Ecology and Management
Table 6 Comparison of bird populations in 3 year-old-clearfell, Abundance values are numbers per kilometre Season
Species (or category)
overstorey removal and mature forest at Bradys using transect counts.
.Abundance Clearfell
Spring
Winter
Green rosella Flame robin Grey Shrike-thrush Grey fantail White-browed scrubwren Tasmanian thombill Yellow wattlebird Black-headed honeyeater Strong-billed honeyeater Yellow-throated honeyeater Crescent honeyeater Silvereye Striated pardalote Canopy birds Mid-layer birds Ground birds Total numbers
-
Green rosella Superb fairy-wren Spotted pardalote Yellow-tailed black-cockatoo White-browed scrubwren Brown thornbill Yellow wattlebird Black-headed honeyeater Strong-billed honeyeater Yellow-throated honeyeater Crescent honeyeater Black currawong Canopy birds Mid-layer birds Ground birds Total numbers
2.5 0.7 0 0 0.7 0 0 0 0 0.2 0 0 0 2.0 1.4 5.9
72 ( 1995) I3 I- 14 V
-.
uals,canopybirds and four speciesof honeyeater were significantly greater in mature forest than in the 17-year-oldclearfell (Table 3 ) . Numbers of speciesin clearfell were alsolower than in mature forestor advancedgrowth retention (Fig. 3) . Numbers of species recorded over all area searcheswere slightly greaterin advancedgrowth retention than for mature forest (Table 4). However, all species seen only in advanced growth retention using this method were ob-
---Overstorey removal
Mature forest
1.9 3.3 3.7 3.0 3.0 2.4 7, -.i 2.5 4.1 3.5 4.1 1.3 0.X 11.1 19.2 9.4 41.6
1.5 3.5 6.X 4.8 7.h 2.0 x.7 7.7 4.5 .37.4.8 4.2 6.8 31.3 35.2 16.1 x7.0
2.4 2.8 0.6 I.1 1.7 I.8 2.2 6.0 3.2 2.8 1.9 0.3 11.9 11.3 5.0 30.6
3.8 -. '6 1.8 1.8 3.2 2.1 2.1 16.7 17.0 5.1 -. ?6 7.7 38.2 14.0 1.5.5 71.4
Significance of difference ---.---____ ..-.-. ._- - ~. c-’x M CXOr u x or -
i lO.iiS h’s
-.
-
i o.oz! NS NS NS c-. 0.00
.._
-
-
NS < 0.05 10.01 10.01
NS (0.01 _.
10.001 10.001 10.001 io.001 < 0.00 1
1
c 0.001 NS NS NS co.01 < 0.001
iO.OOi
served in mature forest during transect counts. Numbers of species observed during transect counts were similar. Two species(number of individuals: dusky robin 5; silvereye 3) were seen in mature forest and not in advancedgrowth retention and two species(pallid cuckoo, 1;wedgetailed eagle,1) were seenin advancedgrowth retention and not in mature forest. Dusky robins were only present in spring. An individual was seennearby a plot in advancedgrowth retention
R.J. Taylor, M.E. Haseler /Forest EcologyandA4anagement
72 (1995) 131-149
143
12 g -u
10
g cn
6 4
8
bE-1, ) , , , , , ,I zo 12
3
4
5
6
7
8
ai
12
3
4
5
6
7
8
12
3
No. of Plots
4
Shelterwood 5
6
7
8
No. of Plots
Fig. 4. Cumulative number of bird species recorded from area searches at Bradys for mature forest and overstorey removal.
Fig. 6. Cumulative number of bird species recorded from area searches at Echo and Clarence for mature forest and shelterwood.
30 25 $ .0
20
$ cn
15 102 0
2
4
6
8
10
12
14
16
18
20
,---
“1 Winter
22
6
1
o
p
20
.g
15
z 3 E
10
5
10
15
20
25
30
35
35 o!
10
15
20
25
30
35
40
45
No. of Time Intervals Fig. 5. Cumulative number of bird species recorded from transects at Bradys for mature forest, overstorey removal and 3-year-old clearfell.
during areasearches.This speciesmay thus have beenpresentin low numbersin advancedgrowth retention. Numbers of speciesare low in the clearfell compared with mature forest and ad-
0
I
I
I
,
I
I
I
I
5
10
15
20
25
30
35
40
45
No. of Time Intervals Fig. 7. Cumulative number of bird species recorded from transects at Echo and Clarence for mature forest and shelterwood.
vancedgrowth retention (Table 4) but thesevalues are not directly comparable owing to the lower sampling intensity in the clearfell. How-
144
R.J. Taylor, M.E. Haseler /Forest Ecology and Management
Table 7 Comparison of bird populations are numbers per eight plots Season
72 (I 995) 131- 149
using area searches in mature forest and shelterwood at Echo and Clarence. Abundance
Species (or category)
____.~ Abundance Shelterwood
Summer
Black-headed honeyeater Black currawong Striated pardalote Tasmanian thombill White-browed scrubwren Yellow wattlebird Green rosella Canopy birds Mid-layer birds Ground birds Total numbers No. of species per plot
Winter
Black-headed honeyeater Yellow-throated honeyeater Yellow wattlebird White-browed scrubwren Crescent honeyeater Brown thombill Canopy birds Mid-layer birds Ground birds Total numbers No. of species per plot
ever, two speciesthat were commonly recorded in the study area did not occur in clearfell, i.e. flame robin and strong-billed honeyeater. 5.2. Overstorey removal
In spring all significant differences between overstorey removal and mature forest showed greaternumbers in mature forest (Tables 5 and 6). However, superbfairy-wrens may have been more abundantin overstoreyremoval asthe differencewascloseto being significant for the area searchesand the same trend was shown in transectcounts (five seenin overstoreyremoval and none in mature forest). Canopy birds and midlayer birds appearedto be more adversely affected than ground birds. The numbers of species recordedin overstoreyremoval and mature forestwere similar (Figs. 4 and 5) .
values
Significance of difference __----~--___-.
Mature
6 8 2 5 1 7 6 10 7 12 35 2.8
18 5 5 4 5 8 1 38 6 13 59 3.5
62 6 3 ? 12 2 68 24 14 106 2.8
I 1 11 5 4 7 13 30 6 48 2.6
-..- _____ ~NS xi; NS NS NS wj iYs i 0.05 KS NS NS NN -: 0.05 NS CO.05 NS NY7 NS (0.05 NS bS KS KS . -_.-
In winter numbersof many speciesweregreater in mature forest and significantly so with the transectdata, aswerethe number of canopy--and ground birds and overall numbers (Tables 5 and 6 ) . Numbers of speciesin overstorey removal was onegreaterthan in mature forest for the area searches(Fig. 4) and three greater in mature forest than in overstorey removal for the transects (Fig. 5). The clearfell supported a lower number of speciesand a lower abundanceof ail species(except greenrosella) and height guilds than either mature forest or overstoreyremoval (Table 6, Fig. 5 ) . Numbers of species recorded overall were equivalent for overstorey removal and mature forest (Table 4). Three species(scrubtit, 3; pallid cuckoo,3; dusky robin, 2 ) wererecorde&fkom overstorey removal and not from mature forest and three species(White’s thrush, 1; satin fly-
R.J. Taylor, M.E. Haseler /Forest Ecology and Management Table 8 Comparison of bird populations are numbers per kilometre Season
72 (1995) 131-149
145
using transect counts in mature forest and sheltewood at Echo and Clarence. Abundance values
Species (or category)
Abundance
Significance of difference
Shelterwood
Mature forest
Summer
Yellow wattlebird Black-headed honeyeater Striated pardalote Grey shrike-thrush Satin flycatcher Grey fantail Tasmanian thornbill Black currawong Green rosella Canopy birds Mid-layer birds Ground birds Total numbers
1.6 2.8 4.4 0.6 0 0.1 0.8 1.3 1.3 9.5 1.9 4.6 17.3
8.1 4.3 7.8 1.1 2.0 1.5 2.5 2.6 1.2 21.2 10.3 5.5 38.3
Winter
Yellow wattlebird Black-headed honeyeater Strong-billed honeyeater Brown thornbill Silvereye Yellow-throated honeyeater ¢ honeyeater Superb fairy-wren Black currawong White-browed scrub wren Green rosella Canopy birds Mid-layer birds Ground birds Total numbers
2.2 8.2 0 2.8 0.4 3.2 5.2 0 4.2 0.5 1.4 11.1 11.9 5.5 29.9
3.1 6.3 2.2 3.0 1.0 2.0 5.0 1.1 0.6 0.9 1.4 12.4 12.5 3.7 30
NS NS
“These differences are due to the sighting of one large flock of 35 currawongs in shelterwood.
catcher, 3; pink robin, 1) were recorded from mature forest and not from overstoreyremoval. 5.3.
Shelter-wood
In summer all significant differencesfor species, canopy birds, mid-layer birds and total numbersshowedgreaternumbersin mature forest (Tables7 and 8). Ground birds did not differ significantly between treatments. Numbers of speciesrecorded in mature forest were higher than in shelterwood(Figs. 6 and 7). Differences betweenthe treatments were less marked in winter than in summer. Two honeyea-
ters (yellow wattlebird and strong-billed honeyeater) and the superb fairy-wren had greater numbers in mature forest and black-headedhoneyeatershad greaternumbers in shelterwood. The significantly greaternumbersof canopybirds observedin plots in shelterwoodis solely the result of greater numbers of black-headedhoneyeaters. The significantly greater numbers of black currawongsand ground birds observedon transectsis attributable to the sightingof a single flock of 35 currawongsin the shelterwood and this result probably doesnot reflect a true differencebetweenthe treatments. More specieswere observedin mature forest on the transectcounts
146
R.J. Taylor, M.E. Haseler /Forest Ecology and Management
(Fig. 7) but this was not the casewith the plots (Fig. 6). Overall, the number of speciesobservedwas slightly greaterin mature forest (Table 4 ). Eight species (satin flycatcher, 18; black-faced cuckoo-shrike, 8; yellow-tailed black-cockatoo, 6; shining bronze-cuckoo,3; laughing kookaburra, 3; scarletrobin, 3; New Holland honeyeater,1; wedge-tailedeagle,1) wereobservedonly in mature forestand five species(spottedquail-thrush, 5; pallid cuckoo,4; goldenwhistler, 1; dusky robin, 1;greycurrawong, 1) wereonly observedin shelter-wood. 6. Discussion Several studies have highlighted the importance of retained trees (both live and dead) within coupes (Smith, 1985; Dickinson et al., 1986;Loyn, 1993). Dead treescan provide nest sitesfor hollow-nestingspeciesand perches,and live treesprovide foragingsubstrates,suchas tissuredor peelingbark, which are best developed on older trees.Smith ( 1985), for example,found retained treesin lo- 15 year old dry sclerophyll regenerationwere intensively usedby birds with 35% of the 40 most frequently recorded birds feeding mainly in retained trees. These studies suggestthat alternative silvicultural systemsto clearfellwhich involve the retentionof more trees and undergrowth should be less detrimental to bird populations. Densities of birds in advancedgrowth retention at Tooms were around half that of mature forest.The greatestdifferencesoccurredin spring and winter. Theseare probably times of greatest stressas birds are breeding in spring and many speciesare lessmobile and in winter food availability would be low. Some species were observedonly in mature forest or only in advanced growth retention.However, few sightingsof these specieswere made and it cannot be concluded that they were restricted to one or other of the treatments. No common specieswere only seen in onetreatment.Thus therewasno evidencethat logging had led to the exclusion of any species. This is in marked contrastto clearfellwheremany
72 (1995)
13 I- 149
speciesdo not utilise the youngregrowth (Pattemore, 1980;Loyn et al., 1980;Kavanagh et al., 1985;Dickinson et al., 1986;Squire, 1990). Two speciesthat werecommon in mature forest were absent from 17-year-old clearfell at Tooms. The absenceof the strong-billed honeyeater can be explained by its specialisedforaging habits,obtaining most of its food from invertebratesunder bark, particularly on the trunks of trees (Thomas, 1980). The young trees in the clearfell coupe are unlikely to provide suitable exfoliating bark for foragingby strong-billed honeyeaters.Patternore ( 1980) also noted the absenceof this speciesfrom young clearfell, The absenceof the flame robin from the clearfell can be related to the high density of the undergrowth. This speciesusesa perch from which it flies to hawk insects or pounce on them on the ground (Blakers et al., 1984). Thus it requires open spacesin which to forage with clumps of vegetationfor perchingin. Such conditions were not provided by the uniformly dense undergrowth presentin the clearfell. The denseundergrowth did, however, provide the most suitable habitat for severalhoneyeatersand small insectivorous birds during summer and autumn. This is in accordwith other studieswhich have found that clearfell provides habitat for particular species with different speciesfavoured at different stagesasthe habitat changesin associationwith successionin the vegetation(Loyn, 1980;Recher et al., 1980; Blakers et al., 1984; Loyn, 1985; Loyn, 1993). Two small insectivores,the superbfairy-wren and the brown thornbill, werefound to be significantly more abundant in the advancedgrowth retention in autumn for the transectcounts. It is possiblethat this result wasbrought aboutby the greatervisibility of birds in the advancedgrowth retention as the distancesover which thesetwo specieswere seen were greater here. The numbers seenin plots were equivalent in advanced growth retention and mature forest for the brown thornbill and greaterin mature forest for the superb fairy-wren. However,the superbfairy-wren was a speciesthat respondedpositively to logging in some of the other study areasand it is possiblethat they may indeed have had greater
R.J. Taylor, M.E. Haseler / Forest Ecology and Management
densities in advanced growth retention in autumn. The flame robin hasa foraging style similar to that of the superb fairy-wren and in autumn the flame robin wasonly seenin advanced growth retention. In autumn the numbersof species seenwas alsogreaterin advancedgrowth retention than in mature forest. Logging using overstorey removal techniques had a similar effect to that of advancedgrowth retention,i.e. a reductionin the densitiesof birds but no evidenceof loss of species.One species, the superbfairy-wren, was favoured by logging. Superbfairy-wrensutilise areaswheredenseundergrowthand opengroundareinterspersed.The creation of openareasamongstthe denseundergrowth via logging damageand snig tracks thus provides favouredhabitat for this species. The retention of a quarter to a third of the canopy with shelterwood logging reduced the impact on bird populations in comparison with clearfell techniqueswith comparablenumbersof speciesoccurring but reduceddensitiesof birds. One species,the black-headedhoneyeater,was more abundantin the shelterwoodareasin winter. This speciesis known to utilise young regrowth (Patternore, 1980) and to breed in disturbed areas such as gardens and orchards (Officer, 1964,cited in Blakerset al., 1984).The satin flycatcher appearedunable to utilise the shelterwooddespite retention of a quarter to a third of the canopy. Satin flycatchers were also only present in the mature forest at Bradys, although they were uncommon in this area. The absenceof this speciesfrom loggedareashasalso been noted by Patternore ( 1980), Loyn et al. (1980) and Dickinson et al. (1986). In contrast to our results,Abbott and Heurck ( 1985) found no reduction in the density of any bird species after removal of over half the treecanopyby logging in the southwestof westernAustralia. However,the forestswhereAbbott and Van Heurch’s study was undertakenare dominated by a single tree speciesand have relatively few bird species present compared with forests in southeastern Australia (Keast, 1976). All of the partial loggingsystemsexamined in this study showedsimilar effects on bird populations. Abundances of nearly all bird species
72 (1995) 131-149
147
werereducedbut only one speciescould be delinitely concluded to have been excluded by logging and one or two speciesat eachsite appeared to havebenefitedfrom logging.This is in marked contrastto the effectsof clearfelling where numbers of speciesand densities dramatically decline after logging and many decades are required before numbers of speciesapproachthat of mature forest (Loyn, 1980;Pattemore, 1980; Loyn, 1985). Thus the changethat is occurring away from clearfelling to partial loggingsystems in the dry forestsin Tasmaniashouldbenefit bird populations. The partially loggedareasexaminedduring this study had only beentreated severalyearsbefore beingsurveyed.It is likely that changesin the bird communities will occur with growth of the disturbed areasof undergrowthand the agingof retained trees. Thus some speciesmay become more common astime sinceloggingincreasesin a similar manner to that which occurs with successionafter clearfelling. A diversity of foreststreatedwith different techniquesand at different agespost-loggingshould increasehabitat diversity overall. However,the importance of retention of mature forest should not be underestimated. Shelterwoodsystems,for example, are, in reality, just a two-stageclearfelltechniquewith the retainedmature canopybeingloggedafter 515yearswhenthe regrowthis over 1.5m in height (Battaglia, 1990). It needs to be remembered that the logged areas that were surveyed were surroundedby mature forest.In an extensivearea of partially loggedforest where mature forest is absent the impact of logging may be greater. Thus, Coulson and Coulsen ( 1980) found that the number of bird species recorded in a regrowth forest resulting from clearfelling in southeastTasmania dropped markedly after an adjoining areaof mature forest waslogged. Acknowledgements
Brett Warren and Peter Lockwood provided information on suitableareasfor sampling.Help with data analysis was provided by Ray Brereton, Bill Brown and Andrew Walsh. Ray Brere-
148
R.J. Taylor, M.E. Haseler /Forest Ecology and Management
72 (199.5) 131-149
Appendix 1 Scientific names of birds observed during the study and the areas in which they occurred ( + , present ): C, clearfell; Ar. advanced growth retnetion; M, mature forest; Or, overstorey removal; S, shelterwood ---Common name Scientific name Tooms Bradys Echo + Clarence __I_. ____. C Ar M C Or M S M T Wedge-tailed eagle Aquila audax -Ic Common bronzewing Phaps chalcopetera t + t -t Yellow-tailed black-cockatoo Calytorphynchus funerus + + + + Green rosella Platycercus caledonicus + + + t t + Pallid cuckoo Cuculus pallidus + + + + Fan-tailed cuckoo Cuculus pyrrhophanus + + t + + + Shining bronze-cuckoo Chrysococcyx lucidus + + + t t + t Laughing kookaburra Cacelo novaeguineae + + Black-faced cuckoo-shrike Coracina novaehollandiae + + + + + + White’s thrush Zoothera dauma + Dusky robin Melanodryas vittata + t + Flame robin Petroica phoenice + + + + t t Pink robin Petroica rodinogaster c + -t Scarlet tobin Petroica multicolor + + Olive whistler Pachycephala olivacea + + t + t Golden whisteler Pachycephala pectoralis + + + t + Grey shrike-thrush Colluricincla harmonica + + + + + + -t Satin flycatcher Myiagra cyanoleuca t + Grey fantail Rhipidura fuliginosa + + + + t + + Spotted quail-thrush Cinclosoma punctatum + + + t + Superb fairy-wren Malurus cyaneus + + + + + iWhite-browed scrubwren Sericornis frontalis + + + + + t + Scrubtit Sericornis magnus + Brown thombill Acanthiza pusila + + + + + + t Tasmanian thombill Acanthiza ewingii + + + + f t f Yellow wattlebird Anthochaera paradoxa + + + + + + t Strong-billed honeyeater Melithreptus validirostris + + + + + t Yellow-throated honeyeater Lichenosiomus flavicolis + + + t l- + + + -IBlack-headed honeyeater Melithreptus affinis + + + + + Crescent honeyeater Phylidonyris pyrrhoptera + + + + + t t Eastern spinebill + + + + .t Acanthorhyncus tenuirostris + + New Holland honeyeater Phylidonyris novaehollandiae + + + t Spotted pardalote Pardalotuspunctatus + + + + + + iStriated pardalote -IiPardalotus striatus + + t + t + t Silvereye Zosterops lateralis + t + Grey butcherbird Cracticus torquatus + + Black currawong Strepera fuliginosa + + + t t + t Grey currawong Strepera versicolor + + + + + Forest raven Corvus tasmanicus + + + f t t t
ton and Peter Brown provided advice on the classification of speciesby height of foraging. Funding was provided by the Commonwealth Department of Primary Industries, Energy and Forestry, Tasmania.
References Abbott, I. and Heurck, P.U., 1985. Response of bird pop&ations in jarrah and yarri forest in Western Austraha following removal of half the canopy of jarrah forest. A&. For., 48: 227-234. Battaglia, M., 1990. High altitude Eucalyptus delegaiertbs
R.J. Taylor, ME. Haseler /Forest Ecology andManagement forests. Tech. Bull. No. 2, Forestry Commission, Native Forest Silviculture, 36 pp. Blakers, M., Davies, S.J.J.F. and Reilly, P.N., 1984. The Atlas of Australian Birds. Melbourne University Press, Melbourne, 738 pp. Coulson, R.L. and Coulsen, G.M., 1980. The effects of forestry practices on bird breeding in open forest. Project Rep. 1980/4, Centre for Environmental Studies, University of Tasmania, 40 pp. Dickinson, K.J.M., Wall, L.E. and Wilson, R.I., 1986. Birds in a partly clearfelled dry eucalypt forest on dolerite in southeastern Tasmania. Pap. Proc. R. Sot. Tasm., 120: 39-49. Duncan, F., 1981. Regeneration and species diversity in a Tasmanian dry sclerophyll forest. In: J. B. Kirkpatrick (Editor), Fire and Forest Management in Tasmania. Tasmanian Conservation Trust, Hobart, pp. 33-44. Gilbert, J.M., 1959. Forest succession in the Florentine Valley, Tasmania. Pap. Proc. R. Sot. Tasm., 93: 129-151. Gilbert, J.M. and Cunningham, T.M., 1972. Regeneration of harvested forests. 1. State forests in Tasmania. Appita, 26: 43-45. Green, R.H., 1982. The activity and movement of fauna in compartment 2, Maggs Mountain, Tasmania, in the first five years of forest regeneration. Rec. Queen Vie. Mus., 75: I-31. Kavanagh, R.P., Shields, J.M., Recher, H.F. and Rohan-Jones, W.G., 1985. Bird populations of a logged and unlogged forest mosaic at Eden, New South Wales. In: A. Keast, H.F. Recher, H. Ford and D. Saunders (Editors), Birds of Eucalypt Forests and Woodlands: Ecology, Conservation, Management. Surrey Beatty and Sons, Sydney, pp. 273-281. Keast, A., 1976. Ecological opportunities and adaptive evolution on islands, with special reference to evolution in the isolated forest outliers of Southern Australia. In: H.J. Frith and J.H. Calaby (Editors), Proc. 16th Int. Omithol. Congr. Australian Academy of Science, Canberra, pp. 573584. Loyn, R.H., 1980. Bird populations in a mixed eucalypt forest used for production of wood in Gippsland, Victoria. Emu, 80: 145-156.
72 (1995) 131-149
149
Loyn, R.H., 1985. Bird populations in successional forests of mountain ash Eucalyptus regnam in central Victoria. Emu, 85: 2 13-230. Loyn, R.H., 1986. The 20 minute search-a simple method for counting forest birds. Corella, 10: 58-60. Loyn, R.H., 1993. Effects of previous logging on bird populations in east Gippsland: VSP Retrospective Study. VSP Tech. Rep. No. 18, Department of Conservation and Natural Resources, 62 pp. Loyn, R.H., MacFarlane, M.A., Chesterfield, E.A. and Harris, J.A., 1980. Forest utilization and the flora and fauna in Boola Boola State Forest in south-eastern Victoria. For. Comm. Vie. Bull., 28: l-80. McCormick, N.D., 199 1. Lowland dry eucalypt forests. Tech. Bull. No. 3, Forestry Commission, Native Forest Silviculture, 47 pp. McCormick, N. and Cunningham, J., 1989. Uneven-aged forest management in Tasmania’s dry sclerophyll forests. Tasforests, 1: 5- 12. Pattemore, V., 1980. Effects of the pulpwood industry on wildlife in Tasmania 3. Succession in bird communities and their habitats. Wildlife Division Tech. Rep. 80/ 1, National Parks and Wildlife Service, Tasmania, 88 pp. Recher, H.F., 1988. Counting terrestrial birds: use and application of census procedures in Australia. Aust. Zool. Rev., 1: 25-45. Recher, H.F., Rohan-Jones, W. and Smith, P., 1980. Effects of the Eden woodchip industry on terrestrial vertebrates with recommendations for management. For. Comm. N.S.W., Res. Note No. 42, 83 pp. Smith, P., 1985. Woodchip logging and birds near Bega, New South Wales. In: A. Keast, H.F. Recher, H. Ford and D. Saunders (Editors), Birds of Eucalypt Forests and Woodlands: Ecology, Conservation and Management. Surrey Beatty, Sydney, pp. 259-27 1. Squire, R.O., 1990. Report on the progress of the Silvicultural Systems Project July 1986-June 1989. Department of Conservation and Environment, Melbourne, 85 pp. Thomas, D.G., 1980. Foraging of honeyeaters in an area of Tasmanian sclerophyll forest. Emu, 80: 55-58. Wilkinson, G.R., 1994. Silvicultural Systems. Native For. Silv. Tech. Bull. No. 5. Forestry Commission, Hobart, 77 pp.