POLLINATION AND REVEGETATION IN THE SOUTH WEST OF WESTERN AUSTRALIA By V.M SAFFER, E.M. BROWN, S.D. HOPPER, J. DELL, R.T. WILLS, A.H. BURBIDGE and J.D. MAJER Cl- Western Australian Naturalists' Club, Perth, 6000 ABSTRACT This report presents the results of a project undertaken by the Western Australian Naturalists’ Club and funded by the Gordon Reid Foundation for Conservation. Aspects of pollination and revegetation in Western Australia were examined, the value of understorcy to pollinators was tested and regeneration of planted stands of eucalypts following fire was monitored. The report is in six parts, namely Part 1, the floral component of survey sites and their flowering patterns, Part 2, bird presence and the foraging activities of honeyeaters, Part 3, fruit set, Part 4. the value of understorey, Part 5, regeneration following fire, and Part 6, general conclusions. More flowering events were recorded in revegetated sites than in remnant sites used as controls More species flowered during spring in revegetated sites than during the other seasons whereas flowering in remnant sites was most prolific during winter. Fifty-six percent of all flowering species were myrtaceous and, of these, eucalypts accounted for 65%. Honeyeaters accounted for 44% of all birds seen. Four generalist species namely Brown, New Holland and Singing Honeyeaters and Red Wattlebirds made up a majority (78%) of honeyeaters seen. More honeyeaters were seen during spring. There was no significant difference in the numbers of honeyeaters seen per visit in revegetated and remnant sites Differences in fruit mass seed mass and the number of seeds per fruit at different sites were not consistent within species and varied between species Viability of seeds was generally high for all species tested and germinability ranged from 6% to 98% More birds and more honeyeaters were seen on the side of a road which included a dense, diverse understorey than on the other side of the road which consisted of a monoculture of Acacia saligna with no understorey. The number of birds did not change significantly before, during or after the introduction of an artificial understorey to both sides of the road. However, honeyeaters foraged more frequently on the introduced understorey under the Acacia saligm than within the dense vegetation. Of 11 nine and 13 year-old eucalypt species that were monitored 12 months after an intense wildfire, seven species reseeded, three resprouted and one did not regenerate (Euadyptus kondininensis). Two 221 of the three species that resprouted are not native to Western Australia; the remaining species are endemic to the State. Repeat monitoring six months later, following summer, showed that most seedlings survived (between 35% and 100%) and, in some species, germination of additional seedlings occurred over summer. As outlined above, there appeared to be greater floral productivity in areas of revegetation than in remnant patches. Concurrently, more birds and, in particular, generalist honeyeaters, were more abundant in revegetated areas and foraged from eucalypt species which were dominant. Honeyeaters were, apparently, effective pollen vectors-, fruit set, viability and germinability was generally high. Revegetation with understorey appeared more attractive to honeyeaters than revegetation without understorey and revegetating with local, native resprouters is more likely to succeed in highly fire-prone environments than reseeders. This study emphasises how much more there is to learn about restoration of the megadiverse communities of the south-west It is clear that self-replacement as has occurred in post-glacial Europe and North America is most unlikely in the south-west Therefore, the importance of protecting all that remains of native vegetation in the south-west is paramount Such remnants will provide the vital sources of local seed and cuttings essential for restoring the incredibly complex and highly localised biodiversity for which the south-west has become world famous. GENERAL INTRODUCTION units within a landscape is dependent upon numerous, interrelated elements. European settlement in Western For example, many floral components Australia in 1827 marked the beginning rely upon the effectiveness of pollinators of large tracts of land being cleared for for reproduction. The process of an expanding human population. The pollination involves the transfer of extent and speed of this degradation of pollen from pollen-bearing surfaces of a native biodiversity has slowed greatly flower to the receptive stigma, usually and restorative processes are currently of a conspecific elsewhere for out- being implemented. Remaining breeders. Of the common animal pollen fragments of remnant vegetation are vectors, namely birds, mammals and being kept and expanses such as road invertebrates, the potential pollination verges, potential corridors and areas of services of birds is most often noted due non-arable land are being revegetated to their visibility, diurnal habits and with native species. However, little relative ease of identification. Most attention has been paid to monitoring mammalian pollinators are nocturnal revegetation in order to assess the and difficult to study (Carthew and resumption of ecosystem function Goldingay 1997, Saffer 1998), while the (Rathcke and Jules 1993, Whelan identification of invertebrate pollinators 1989). Indeed, the health of the falls out of the scope of most observers. remaining remnants also begs Recently, Brown et al. (1997) compiled assessment. a database of specific observations of The self-sustainability of all functional animals visiting flowers of native plants 222 in Western Australia This handbook species in revegetation, are included. was the result of a project funded by the Of the satellite studies, the first Gordon Reid Foundation for examined differences in pollinator Conservation and administered by the activity in revegetation with Western Australian Naturalists' Club. understorey versus revegetation Within the text, the process of without understorey, and the second pollination was recognized as vital for assessed regeneration of revegetation plants to set seed for future generations. following a major perturbation, namely Brown et al. (1997) indicated that fire. Common names are used for birds restoration generally concentrates on (see Appendix 1) and, because of establishing plant communities and that regional differences in common names it is assumed that the faunal for plants, scientific names are used for community, including pollinators, will plants (see Appendix 2). follow naturally. Following the publication of this handbook, members of the Western Australian Naturalists' SURVEY SITES Club considered it necessary to monitor Seventy-six sites were monitored. These more closely, and compare, pollinators sites were selected by volunteers and in patches of remnant vegetation and many were part of a broader Birds on compare them to pollinators in Farms Project in Western Australia 1996 - revegetated, regenerated and cleared 1999 (Newbey 1999) conducted by areas. To gain information from diverse Birds Australia. Sites included those landscapes over vast areas, and to raise with remnant vegetation, those that had the awareness of the importance of been cleared and kept that way, sites pollination as a process needed for self- that had been cleared and subsequently sustaining revegetation, funding was revegetated, and those which had been sought to conduct a community-based cleared and regenerated naturally monitoring program. Once again the without human intervention (Table 1, Gordon Reid Foundation of Photos 1,2,3 and 4). Within this latter Conservation provided financial category of regeneration, one had been support burnt and two had been cleared and Flowering patterns and the presence and then flooded following heavy rains. The foraging activities of birds in diverse landscapes in the south west of Western . Table 1 The number of sites in each Australia were monitored from summer category of vegetation. 1997 through to autumn 1999. Individuals in rural areas volunteered to Vegetation type Number cf conduct observations in remnant and sites revegetated sites both on and off their properties. Fruit was collected from Remnant 29 selected plant species in these sites to Cleared: no regeneration 2 assess the effectiveness of pollinators in Revegetation: terms of the viability and germinability road verge 21 of seed within the fruit. The results of on-farm 21 this study are synthesized here and the Regeneration: results of two satellite studies, both of following fire 1 post clearing 2 which relate to the selection of plant 223 c o a O(NOOr0O(N-.O-^rrlfnm(N^O-HC0-H^-HC0^OO§!j£ a) V > g s • a o § § n. rs OO — OOO — O — OOOOOOOOOOOOOOOOrn o ati c o fcr h l & c a s at e •Sg ’S8 OOOOOOOOOOOOOOOOOO—<00000—<M pe 8 0 y c n t o ati eget —. O —. —«(N^"0(N0(N0—(OfSfOtOO-. O O O —< — On v d n a f sites btotal Total o u s .C g S r u Q e b m u n e h d t n ed a *•a I rr-f ’•'t -r- Vcn- *—* coni ra—o rb^i- oao y0o o ^^ co ouo jo ;ot*j o<n ucoo <n r—-1(cid:9632) foo> cn yo”>j olo vey I (cid:9632)t -t i- oo co ® o '^c o 'o in K o o co ® L ^ n r u s s e of sit jtn^ rmn rtc ^O -Om ^rf^ ^Otj- Oin ^^O CoO .-(cid:9632) Or1 'int^vO^ PO Prl oO^^'A P e K co o ’— *— 'rn '— 'n ri o ^ ^ ro ^ "t -,t 1* ’l- ’^i d nfNri^irorOfOfOf^fOrororOfOr^rororOrOfOfOror^ror^ u git n o d l e an Ull] .b >r Sb bi Cl l!j a cl 8 — « d 5 ||| u It&s&SliiS atit L C !r- 2. | e •2 bl (N iT) v£) a T 224 location of sites is shown in Table 2 and as rewards to potential pollinators Figure 1. (Simpson and Neff 1983). The patterns of food resource availability, therefore, influence pollinator visitation rates PART 1: FLORAL COMPONENT OF (Ford and Paton 1982, Paton 1988, SURVEY SITES AND THEIR Wills 1989, Pyke et al. 1989, Armstrong FLOWERING PATTERNS 1991, Saffer 1998). Indeed, close relationships have been shown between INTRODUCTION flower food resources and local and Pollen and nectar are, by far, the most regional movements of Australian bird widely used attractants offered by plants pollinators (Keast 1968, Paton 1982, Figure 1. Map of south-western Australia. Circled numbers represent location of survey sites (see Table 2). 225 Paton 1985, Brown and Hopkins 1996). number of proteaceous species in In this study, pollinator food resource revegetated sites (20 species) and in availability was assessed during surveys remnant sites (19 species) resulted in 71 by recording flowering patterns of major and 48 flowering events respectively. nectar-producing species More than ten species of acacias resulted in 58 flowering events in revegetated areas, whereas only 14 METHODS flowering events from five species were From summer 1997/98 to autumn 1999, recorded in remnant sites. The once in each season, volunteers remaining 107 flowering plants came monitored 76 sites (Table 2, Figure 1). from 21 families (see Table 3). Initially, volunteers listed plant species Within the revegetated sites, more present within each site, plants were species flowered during spring followed then scored during seasonal surveys if by the number flowering during winter, they were flowering. Individual plants whereas this pattern was reversed in the were scored as flowering if there was at remnant sites (Table 3). The numbers least one flower open. The list of plant of plants flowering in each season in the species on all sites is extensive. cleared and regenerated sites were so Therefore only those species that were low as to be meaningless in terms of recorded as flowering are included. seasonal trends. Plants were identified using relevant keys (Grieve and Blackall 1975, Grieve 1980, Grieve 1981, Grieve 1988, Grieve DISCUSSION 1998). Nomenclature followed Western Habitat remnants and areas of Australian Herbarium (1999). revegetation exist as small ecological units, each the result of and subject to unique conditions (Ehrlich and Murphy RESULTS 1987, Hobbs 1993). Patterns of The number of flowering plants flowering within these units are recorded during all surveys totaled 676 dependent on many factors which vary species (Table 3). Of these, a majority temporally and spatially (Wills 1989). (446 = 66%) were flowering in Sites surveyed in this study spanned a revegetated sites (N = 42), followed by vast area and were subject to a range of the number flowering in remnant sites environmental conditions. There was (204 = 30%) (N = 29). Only 10 plants also a large disparity in the number of were recorded as flowering in sites monitored in each vegetation regenerated sites and 15 in cleared sites. category. Therefore, caution must be The family Myrtaceae accounted for exercised when making generalisations 56% of all flowering species, with 65% about the floral dynamics across (N = 246) being eucalypts. Revegetated different habitats (Ehrlich and Murphy sites had more flowering events 1987). recorded (255) from more myrtaceous In this study, myrtaceous and species (55) than in remnant sites (103 proteaceous species together accounted flowering events from 39 species). for a majority (76%) of plants flowering Proteaceous species numbered 119 in both remnant and revegetated sites. (18%) and acacias (Mimosaceae) The dominance of these two families is accounted for 11% (Table 3). A similar not uncommon in Western Australian 226 landscapes (Beard 1990, Wills ec ai ranging in size from 0.3ha to 0.5ha were 1990). Overall, it appears that there was surveyed by volunteers walking through greater species diversity and each site for 20-30 minutes as early as productivity in revegetated sites than possible each morning. Birds were remnant sites. This difference may be an scored if present at each site during each artefact of biased site-selection by the monitoring session, and the foraging volunteers in terms of greater activities of honeyeaters were noted productivity, particularly with reference where possible. Every attempt was made to revegetated sites. Nevertheless, the not to count the same bird twice. results indicate broadly that floral productivity in remnant areas may be in need of some restoration. Very little RESULTS activity was recorded on regenerated and cleared sites and is not discussed Overall, 1004 sightings of 75 species of further. birds were recorded (Appendix 3). Of these, 44% (438 individuals of 16 The seasonal patterns of flowering in species) were honeyeaters (Table 4), this study may be related to the time with Brown, New Holland and Singing observations were made and, therefore, Honeyeaters and Red Wattlebirds may not accurately reflect patterns that comprising 78% of all honeyeaters seen. occurred. Brown Honeyeaters were by far the most common species seen (Table 4). PART 2: BIRD PRESENCE AND THE More honeyeaters were recorded in FORAGING ACTIVITIES OF revegetated areas (Table 4), followed by HONEYEATERS the numbers seen in remnant sites. However, the numbers of honeyeaters Fragmentation and degradation of seen per visit in remnant, revegetated formerly continuous vegetation is likely and regenerated sites were not to impact on plant-pollinator significantly different (F2 15= 1.827, P = interactions and, consequently, on 0.194). No honeyeaters were seen in plant demography and recruitment cleared sites. (Rotenberry 1985, Aizen and Feinsinger 1994). The role of pollination is vital in Combining the first and second seasons the sustainability of remnant vegetation of summer (1997 and 1998) and autumn and in the process of restoration (1998 and 1999), more honeyeaters biology, yet has received little attention were seen, per visit, during the spring (Saunders and Ingram 1995, Neal months in both remnant and 1998). In this study, the presence of revegetated sites than during autumn or avian pollinators was monitored in areas winter, and the lowest numbers were of varied vegetated status, and their seen per visit in summer for both activities recorded. vegetated states (Figure 2). More honeyeaters were sighted per visit in autumn in regenerated sites than during METHODS the other seasons (Figure 2). From summer 1997/1998 to autumn Of the 438 honeyeaters seen during the 1999, once each season, volunteers surveys, 282 (64%) were observed monitored 76 sites (see Part 1 for foraging (Table 5). As more myrtaceous methods and locality map). Areas species were observed flowering overall, 227 Table 3. The number of plants flowering in survey sites from summer 1997 to autumn 1999. Family Genus species Revegetated Remnant Sum Aut Win Spr Sum Aut Sum Aut Win Spr Sum Aut 97 98 98 98 98 99 97 98 98 98 98 99 Amaranthaceae Ptilotus spp. Anacardiaceae Schinus terebinthifolia Bignoniaceae Tecoma sums Casuarinaceae Allocasuarim acu t irnlvis Allocasuarinacampestris Allocasuarim huegeliam Allocasuarinasp. Casuarim obesa 1 1 1 Casuarim spp. 1 5 4 3 2 Cupressaceae Actinostrobusarenarius 1 Dilleniaceae Hibbcrtui acerosa 1 Hibbertia cuneiformis 2 2 1 Hibbertia sp. 1 1 2 1 Epacridaceae Astrolorm serratifolium 1 1 Astrolorm spp. 1 2 1 Leucopogon spp. 2 Goodeniaceae Dampiera spp. 4 Gooden ia sp. 1 Scaevola sp. 1 Haemodoraceae Anigozanthos manglesii Anigozanthos sp. 1 1 lridaceae Patersonia spp. Lamiaceae Westringia spp. 1 1 Lobeliaceae Isotoma spp. Loranthaceae Nuytsia floribunda Malvaceae Hibiscus sp. Mimosaceae Acacia acuminata 3 1 Acacia celastrifolia Acacia chry sella Acacia decurrens 228 Cleared Regenerated Total Number in Family Sum Aut Win Spr Sum Aut Sum Aut Win Spr Sum Aut Total %of 97 98 98 98 98 99 97 9898989899 total 3 3 0.4 1 1 0.1 1 1 0.1 2 23 3.4 1 1 1 3 15 1 1 0.1 1 15 2.2 1 8 6 2 8 1.2 4 2 4 6 0.9 1 1 1 5 0.7 4 3 3 0.4 5 5 0.7 2 2 0.3 3 3 0.4 1 1 0.1 6 74 10.9 2 4 3 229 Table 3. (continued). Family Genus species Revegetated Remnant Sum Aut Win Spr Sum Aut Sum Aut Win Spr Sum Aut 97 96 98 98 98 99 97 98 98 98 98 99 Mimosaceae (cont.) Acacia drummondii 2 Acacia lasiocarpa 1 Acacia 1xntadenia 1 Acacia prism if alia 2 Acacia pulchclla 2 6 1 3 Acacia pycnantha 1 Acacia sciligna 2 1 7 Acacia tetanophylla 1 Acacia spp 3 12 6 2 1 1 2 1 1 Myrtaceae Agonis flexuosa 2 Agonis linearifolia 1 Agonis fxirviceps 1 Baeckea muricata 1 Beaufonia schaueri 1 Beaufonia squarrosa 1 1 1 Eucalyptus camaldulensis 1 1 1 2 4 1 1 1 Eucalyptus capillosa 1 2 Eucalyptus citriodora 1 1 Eucalyptus cUidocalyx 1 1 Eucalyptus conferruminata 1 1 1 Eucalyptus diptera 1 Eucalyptus diversicolor 1 1 2 2 Eucalyptus eremophila 1 1 Eucalyptus erythroriema 1 Eucalyptus ficifolia 2 Eucalyptus gardneri 3 Eucalyptus globulus 1 1 Eucalyptus grandis 1 Eucalyptus kruseana 1 1 Eucalyptus lehmannii 1 1 1 1 1 Eucalyptus leucoxylon 3 2 2 1 Eucalyptus longicomis 1 Eucalyptus loxophleba 2 1 1 2 Eucalyptus macrandra 1 2 1 1 Eucalyptus macrocarpa 1 Eucalyptus marginata 1 4 1 1 Eucalyptus rnegacarpa 1 Eucalyptus mellidora 1 Eucalyptus micranthera 1 Eucalyptus micnxorys 1 Eucalyptus occidentals 1 6 5 1 6 1 Eucalyptus patens 1 3 1 Eucalyptus phitycorys 1 230