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Forest canopy loss due to plant pathogens, insect or abiotic factors significantly alters habitat and resource availability for animals, which has flow-on effects for whole ecosystems. The tuart (Eucalyptus gomphocephala) has been in decline throughout its geographic range; this is likely associated with watertable and salinity changes, although a plant pathogen (Phytophthora multivora) has also been implicated. We examined the relative abundance of common brushtail possums (Trichosurus vulpecula) across 12 sites (each 0.72 ha) selected on the basis of the health of dominant tuart trees (six ‘healthy’ and six ‘declining’ sites). Habitat variables (understorey, tuart dimensions and density, tree hollows, tree-to-trap distance) and tuart tree health (crown loss, epicormic regrowth) were compared with possum abundance. Possums were detected at most sites. There was no significant difference between brushtail possum numbers at ‘healthy’ or ‘declining’ sites, although marginally more possums were recorded at declining sites (5.7 ± 1.5 (s.e.), n = 6 sites) compared with healthy sites (3.3 ± 0.7; Cohen’s effect size d = 0.80). Slightly higher abundance of possums was associated with sites that had a greater density of smaller-diameter but taller tuart trees. ‘Declining’ sites, with more epicormic regrowth and greater tree densities, may provide more palatable food resources for possums.

Natural regeneration is a critical component of forest ecosystems sustainability. Local extinction can occur without adequate regenerationor seedling recruitment prior to adult senescence. The urban and peri-urban environment is particularly challenging for recruitment. For example, although many forest species have specific requirements involving fire events, few opportunities associated with fire exist in contemporary urban and peri-urban environments. For our study species, Eucalyptus gomphocephala, en masse recruitment can occur in ashbeds following a hot fire. However, this may not occur following low-intensity, fuel reduction burns that are prescribed for many E. gomphocephala woodlands and forests. Nevertheless, ashbeds could be created by constructing and burning coarse woody debris (CWD) piles. In a series of collaborative case studies involving community groups, NGOs and Local and State Government agencies, we investigated whether seedling recruitment could be facilitated through broadcast seeding after: a) creating CWD piles prior to a low intensity, prescribed burn; b) naturally-occurring ashbeds following a hot summer wildfire; and c) creating CWD piles and then burning the piles only. We found that regeneration of this post-fire, canopy gap regenerator can be facilitated by broadcast seeding naturally occurring or created ashbeds. However, it seems that protection from seed harvesters and herbivores is vital. These case studies provide tools that can be used to preserve the natural demographics in populations with specific regeneration requirements in a range of environments by leveraging natural recruitment processes and community involvement. Importantly, it is the conservation of these urban and peri-urban ecosystems that will be vital in maintaining connection between people and the environment into the future.

Understanding the environmental parameters that drive adaptation among populations is important in predicting how species may respond to global climatic changes and how gene pools might be managed to conserve adaptive genetic diversity. Here, we used Bayesian FST outlier tests and allele-climate association analyses to reveal two Eucalyptus EST-SSR loci as strong candidates for diversifying selection in natural populations of a southwestern Australian forest tree, Eucalyptus gomphocephala (Myrtaceae). The Eucalyptus homolog of a CONSTANS-like gene was an FST outlier, and allelic variation showed significant latitudinal clinal associations with annual and winter solar radiation, potential evaporation, summer precipitation and aridity. A second FST outlier locus, homologous to quinone oxidoreductase, was significantly associated with measures of temperature range, high summer temperature and summer solar radiation, with important implications for predicting the effect of temperature on natural populations in the context of climate change. We complemented these data with investigations into neutral population genetic structure and diversity throughout the species range. This study provides an investigation into selection signatures at gene-homologous EST-SSRs in natural Eucalyptus populations, and contributes to our understanding of the relationship between climate and adaptive genetic variation, informing the conservation of both putatively neutral and adaptive components of genetic diversity.

th , 2012; revised July 10 th , 2012; accepted July 25 th , 2012 Ecosystems in Mediterranean climate regions are projected to undergo considerable changes as a result of shifting climate, including from extreme drought and heat events. A severe and sudden dieback event, occurring in regionally significant Eucalyptus gomphocephala woodland in Western Australia, coincided with extreme drought and heat conditions in early 2011. Using a combination of remote sensing and fieldbased approaches, we characterized the extent and severity of canopy dieback following the event, as well as highlighted potential predisposing site factors. An estimated 500 ha of woodland was severely affected between February and March 2011. Tree foliage rapidly discolored and died over this period. In the affected portion of the woodland, approximately 90% of trees greater than 20 cm DBH were impacted, while in the adjacent unaffected woodland 6% showed signs of damage. Tree density in the unaffected area had approximately 4.5 times more trees than the affected woodland. Precipitation drainage patterns are thought to explain the difference between affected and unaffected woodland. Dropping groundwater levels, a relatively shallow soil profile, and extreme drought and heat in 2010-2011 are thought to predispose water-shedding sites to drought-triggered canopy dieback during extended periods of dryness. Tracking forest health changes in response to severe disturbance is an important key to deciphering past and future vegetation change.

Phytophthora multivora is associated with the rhizosphere of declining Eucalyptus gomphocephala, Eucalyptus marginata and Agonis flexuosa. Two pathogenicity experiments were conducted. The first experiment examined the pathogenicity of five P. multivora isolates and one Phytophthora cinnamomi isolate on the root systems of E. gomphocephala and one P. multivora isolate on the root system of E. marginata. In the second experiment, the pathogenicity of P. multivora to E. gomphocephala and E. marginata saplings was measured using under-bark stem inoculation. In Experiment 1, the P. cinnamomi isolate was more aggressive than all P. multivora isolates causing significant loss of fine roots and plant death. Two P. multivora isolates and the P. cinnamomi isolate caused significant losses of E. gomphocephala fine roots 0–2 mm in diameter and significantly reduced the surface area of roots 0–1 mm in diameter. One P. multivora and the P. cinnamomi isolate significantly reduced the surface area of roots 1–2 mm in diameter. Two of the P. multivora isolates significantly reduced the number of E. gomphocephala root tips. In E. marginata, the length and surface area of roots 0–1 mm in diameter and number of root tips were significantly reduced by P. multivora infestation. Rhizosphere infestation with the P. multivora isolates and P. cinnamomi isolate on E. gomphocephala, and one P. multivora isolate on E. marginata, did not significantly influence the foliar nutrient concentrations. In Experiment 2, under-bark inoculation with P. multivora caused significant lesion extension in E. gomphocephala and E. marginata saplings, compared to the control. We propose that P. multivora is inciting E. gomphocephala and E. marginata decline by causing fine root loss and subsequently interfering with nutrient cycling throughout the plant. The impact of fine root loss on the physiology of plants in sites infested with P. multivora requires further research.

Fire regimes in temperate forests and woodlands have changed significantly in Australia since European settlement. We hypothesised that an absence of fire leads to the increased development of woody understorey/ midstorey and that this may be correlated with decreased water and/or nutrient availability in overstorey temperate eucalypts currently declining in health. Sites with a history of being long unburnt or recently (and frequently in the case of Eucalyptus gomphocephala woodland) burnt (relative to median fire intervals for the vegetation type) were established in E. gomphocephala woodland in Western Australia and in Eucalyptus delegatensis forest in Tasmania. In long unburnt sites in both E. gomphocephala woodland and E. delegatensis forest, there was greater percent cover of understorey/midstorey and eucalypts had higher water use efficiency, indicative of greater soil water limitation, as estimated by foliar carbon isotope ratios. In E. gomphocephala woodland foliar Cu and Zn were significantly lower in eucalypts of long unburnt, relative to frequently burnt, sites. In E. gomphocephala woodland, understorey/midstorey (shrub) cover was positively correlated, and foliar copper and zinc levels were negatively correlated to health of overstorey trees. In E. delegatensis forest foliar phosphorus (P) was significantly lower in eucalypts of long unburnt, relative to recently burnt, sites. In E. delegatensis forest moss cover was positively correlated and foliar P was negatively correlated to health of overstorey trees. The understorey/midstorey that develops in the long absence of fire may alter ecological processes that lead to less favourable water- and nutrientrelations in E. gomphocephala woodland and E. delegatensis forest that are associated with decline in crown health. However this study does not definitively show a link between understorey/midstorey vegetation and overstorey tree water- and nutrient-relations. This link will be investigated in future research.

The objective of this study was to investigate how the management practices of prescribed fire and understorey vegetation removal affect water and nutrient relations of old, yet prematurely declining Eucalyptus gomphocephala. Long unburnt sites were established in Yalgorup National Park, Western Australia, adjacent to frequently burnt state forest sites. Trees were allocated to vegetation clearing, prescribed fire or no prescribed fire treatments. Prescribed fire was achieved in only one long unburnt national park site so that the results were pseudoreplicated but analysed accordingly. Soil chemistry, plant nutrient availability and tree foliar carbon and nitrogen isotope ratio and nutrient concentration were investigated. No effects of vegetation clearing were found. Prescribed fire sites were associated with sky exposure and bare ground whereas no prescribed fire sites were associated with shrub and litter cover and litter depth. Foliar carbon isotope ratios were significantly more negative in prescribed fire, relative to no prescribed fire, treatments on long unburnt sites. Soil exchangeable Zn and Mn and plant available (estimated by charged resin beads) Mg were higher on prescribed fire, relative to no prescribed fire, long unburnt sites. Seedling bioassays indicated elevated P and Cu availability on prescribed fire, relative to no prescribed fire, treatments. In overstorey E. gomphocephala, foliar N levels were elevated (but not to excessive levels), and there was a trend toward elevated foliar Mn, in prescribed fire relative to no prescribed fire treatments on long unburnt sites. In the context of our large-scale pseudoreplicated case study, prescribed fire provided a pulse of water and N, (with some indications towards provision of elevated Mn, Cu and Mg) availability to E. gomphocephala in decline on sites with a history of a long absence of fire that may in part underpin observations of elevated tree health on sites that have a history of relatively frequent fire.

Management interventions are needed to reverse the decline of Tuart (Eucalyptus gomphocephala) woodland in the Yalgorup area of south-west Western Australia where the largest intact remaining example of this ecosystem is located. Although the cause of the decline is uncertain and several factors may be involved, management action should not be withheld because the decline process is not fully understood. We contend that the reduction in fire frequency over the last 50 years has led to an increase in understorey density, particularly of Western Australian Peppermint (Agonis flexuosa), resulting in greater competition for resources, which may in turn have increased the susceptibility of healthy woodland to decline. In contrast to Tuart regeneration, which is usually tied to fire, Western Australian Peppermint can establish readily in unburnt woodland. Further, once Western Australian Peppermint seedlings develop to the lignotuberous stage, they can resprout vigorously after fire. Therefore, a combination of fire and the physical removal of understorey in sites where this species has formed extensive thickets is required to: (i) provide an opportunity for regeneration of Tuart in both healthy and declining stands; (ii) improve the chances of sustained recovery of Tuart trees in declining stands; and (iii) ensure heterogeneity in the vegetation at multiple scales, a recognized strategy for conserving biodiversity and increasing ecosystem resilience. We propose that this approach may also be relevant to other tree decline syndromes in southern Australia. However, fostering community support for active intervention using thinning and fire in conservation reserves and staging the operations within an experimental framework will be important for such action to gain both the social and scientific acceptance necessary for it to be applied widely.

Eucalyptus gomphocephala (tuart) is a tree native to the southwest coast of Western Australia, where, in some areas, there is a significant decline in the health of tuart. Botryosphaeriaceous taxa have been isolated as endophytes and canker pathogens from numerous hosts in many parts of the world and have been implicated in the decline of E. gomphocephala. In the present study, endophytic fungi were isolated from a wide variety of native woody plant species (Acacia cochlearis, A. rostellifera, Allocasuarina fraseriana, Agonis flexuosa, Banksia grandis, E. gomphocephala, E. marginata and Santalum acuminatum), at two locations in native E. gomphocephala woodland; a site in decline at Yalgorup National Park and a healthy site at Woodman Point Regional Park. Of the 226 isolates obtained, 154 were botryosphaeriaceous taxa, 80 % of which were found to be Neofusicoccum australe, isolated from all hosts at both collection sites. Four new species are described, Dothiorella moneti, Dothiorella santali, Neofusicoccum pennatisporum, and a species belonging to a genus only recently included in the Botryosphaeriaceae, Aplosporella yalgorensis. The other species isolated were Botryosphaeria dothidea on the new hosts A. rostellifera, A. cochlearis and E. marginata and Dichomera eucalypti, on the new host E. marginata. None of the new species formed lesions on excised stems of their host species, E. gomphocephala, or a common plantation species, E. globulus. However, Neofusicoccum australe formed lesions on excised stems of E. globulus and E. gomphocephala.

International audience; Effects of polluted sea-spray on leaves of Acacia cyanophylla Lindl. and Eucalyptus gomphocephala Dc. in Tunisian coast. A deterioration of the coastal vegetation of the Cape Bon in Tunisia has been observable for these two last decades. In many points of the coast, the peuplement of Acacia cyanophylla Lindl. and Eucalyptus gomphocephala Dc. are touched. The sheets of the damaged trees present a marked reduction of their relative content water compared to that of the healthy sheets, with deterioration of their surface on the epicuticular waxes. These deterioration are related to the recent presence in the marine spray of several pollutants like anionic surfactants. The experiences results in laboratory confirm hypothesis that when the sea-spray contains the surfactant and hydrocarbons, they then have a very significant impact on the sheets with in particular a deterioration of the cuticle. Indeed Na+ and Cl- ions and the pollutants present in the spray can then largely cross the cuticular barrier and exert their deleterious effects on leaf tissues.; Un dépérissement de la végétation côtière du Cap Bon en Tunisie est observable depuis ces deux dernières décennies. En de nombreux points de la côte, les peuplements d'Acacia cyanophylla Lindl. et d'Eucalyptus gomphocephala Dc. sont touchés. Les feuilles des arbres dépérissants présentent une réduction marquée de leur teneur relative en eau par rapport à celle des feuilles saines, avec des altérations de leur surface au niveau des cires épicuticulaires. Ces dépérissements sont liés à la présence récente dans les embruns marins de plusieurs polluants comme des tensioactifs anioniques. Les résultats d'expériences en laboratoire confirment l'hypothèse que lorsque les embruns marins contiennent des tensioactifs et des hydrocarbures, ils ont alors un impact très important sur les feuilles avec en particulier une altération de la cuticule. En effet les ions Na+,Cl- et les polluants présents dans les embruns peuvent alors franchir largement la barrière cuticulaire et exercer leurs effets néfastes sur les tissus foliaires.

The vegetation of Kings Park, near the centre of Perth, Western Australia, once had an overstorey of Eucalyptus marginata (jarrah) or Eucalyptus gomphocephala (tuart), and many trees still remain in the bushland parts of the Park. Avenues and roadsides have been planted with eastern Australian species, including Eucalyptus cladocalyx (sugar gum) and Eucalyptus botryoides (southern mahogany), both of which have become invasive. The present study examined the effect of a recent burn on the level of herbivory on these native and exotic eucalypts. Leaf damage, shoot extension and number of new leaves were measured on tagged shoots of saplings of each tree species in unburnt and burnt areas over an 8-month period. Leaf macronutrient levels were quantified and the number of arthropods on saplings was measured at the end of the recording period by chemical knockdown. Leaf macronutrients were mostly higher in all four species in the burnt area, and this was associated with generally higher numbers of canopy arthropods and greater levels of leaf damage. It is suggested that the pulse of soil nutrients after the fire resulted in more nutrient-rich foliage, which in turn was more palatable to arthropods. The resulting high levels of herbivory possibly led to reduced shoot extension of E. gomphocephala, E. botryoides and, to a lesser extent, E. cladocalyx. This acts as a negative feedback mechanism that lessens the tendency for lush, post-fire regrowth to outcompete other species of plants. There was no consistent difference in the levels of the various types of leaf damage or of arthropods on the native and the exotic eucalypts, suggesting that freedom from herbivory is not contributing to the invasiveness of the two exotic species.

Rehabilitation with native plant species of an experimental titanium dioxide residue containment pond on dune swales at Capel, Western Australia was undertaken in 1990. The treated residue comprised unreacted ilmenite, coking coal, metal hydroxides, gypsum and lime inerts, and titanium dioxide. It was an inert, insoluble, non-toxic, clay-like material. This paper describes the growth and establishment of terrestrial vegetation in the residue material after five years and its associated symbiotic root fungi and ant communities. The total number of plant species present after five years was comparable to a nearby Eucalyptus gomphocephala woodland and dune vegetation. Vegetation cover was similar to the dune site but less than the woodland. Litter cover was similar to the burnt dune site. Mycorrhizal infection rates were similar in the roots of plant examined in experimental and control sites. Ant species richness was approaching levels in control sites. Soil analysis showed that topsoil in the resi...

†Background and Aims Few phylogeographic studies have been undertaken of species confined to narrow, linear coastal systems where past sea level and geomorphological changes may have had a profound effect on species population sizes and distributions. In this study, a phylogeographic analysis was conducted ofEucalyptusgomphocephala (tuart), a tree species restricted to a 400 × 10 km band of coastal sand-plain in south west Australia. Here, there is little known about the response of coastal vegetation to glacial/interglacial climate change, and a test was made as to whether this species was likely to have persisted widely through the Last Glacial Maximum (LGM), or conforms to a post-LGM dispersal model of recovery from few refugia. †Methods The genetic structure over the entire range of tuart was assessed using seven nuclear (21 populations; n ¼ 595) and four chloroplast (24 populations; n ¼ 238) microsatellite markers designed for eucalypt species. Correlative palaeodistribution modelling was also conducted based on five climatic variables, within two LGM models. †Key Results The chloroplast markers generated six haplotypes, which were strongly geographically structured (GST ¼ 0.86 and RST ¼ 0.75). Nuclear microsatellite diversity was high (overall mean HE 0.75) and uniformly distributed (FST ¼ 0.05), with a strong pattern of isolation by distance (r 2 ¼ 0.362,P ¼ 0.001). Distribution models of E. gomphocephala during the LGM showed a wide distribution that extended at least 30 km westward from the current distribution to the palaeo-coastline. †Conclusions The chloroplast and nuclear data suggest wide persistence of E. gomphocephala during the LGM. Palaeodistribution modelling supports the conclusions drawn from genetic data and indicates a widespread westward shift ofE.gomphocephala onto the exposed continental shelf during the LGM. This study highlights the importance of the inclusion of complementary, non-genetic data (information on geomorphology and palaeoclimate) to interpret phylogeographic patterns.

The tuart–banksia woodlands of the Swan Coastal Plain in Western Australia are characteristic vegetation communities of this coastal region, and Eucalyptus gomphocephala DC. (Myrtaceae; tuart) is an iconic tree of these communities. The species primarily occurs as a tall single-stemmed tree, but at the northern end of the distribution, it also occurs in a multi-stemmed form. Growth habit is frequently used as a taxonomic character in eucalypts, with many complexes having tree and mallee forms, although the genetic characterisation of growth habit in eucalypts has been limited. We investigated the genetic and morphological differentiation among populations of tree and multi-stemmed forms of tuart at the northern end of its distribution. Although the populations showed moderate levels of genetic diversity on the basis of microsatellite markers, as might be expected from populations on the periphery of the distribution, there was no evidence of genetic differentiation associated with the tree and multi-stemmed forms. Morphometric analysis showed some differences in the size of buds and fruits among the populations. Our analysis is consistent with environmentally induced variation in tuart in near-coastal populations where plants grow on poor soils and form may be affected by wind and salt exposure. This result adds to other evidence from pines and Nothofagus of environmental rather than genetic influences on growth form, particularly in stressful environments.

The anthropogenic movement of Eucalyptus species beyond their natural distributions is increasing the opportunity for interspecific hybridisation. The conservation implications arising from hybridisation between indigenous and introduced eucalypt species in modified urban landscapes is an increasingly important management issue that requires an assessment of risk. It has been claimed that much of the tuart (Eucalyptus gomphocephala DC., Myrtaceae) seed in Kings Park, a large urban bushland remnant in Perth, Western Australia, is of hybrid origin with introduced eastern Australian eucalypts, and especially with E. cladocalyx. Using molecular markers, we tested this claim and determined whether hybridisation in tuart is a conservation management issue in Kings Park, as well as the adjacent Bold Park. Eight microsatellite markers were used to genotype 220 open-pollinated tuart seedlings from 19 families. Allele frequency estimates for tuart were generated by genotyping 42 mature tuart trees. Forty-four trees of four alternative species thought to be capable of hybridising with tuart in these parks, including two non-indigenous species, E. cladocalyx and E. camaldulensis, and two indigenous species, E. decipiens and E. rudis, were also genotyped. Pairwise FST between tuart and each alternative species for these markers ranged from 0.105 to 0.204. A hybrid-index analysis of seedling genotypes showed no significant evidence for hybridisation, and no alternative species private alleles (n = 35) were found in any tuart offspring genotypes. A likelihood analysis showed that the maximum likelihood of observing no private alleles of the alternative species in the progeny occurred at a hybridisation frequency of zero for all four alternative species. We conclude that hybridisation between tuart and non-indigenous species is not currently a conservation management issue in Kings Park and Bold Park. Rather, the invasion of pure non-indigenous species, and in particular E. cladocalyx, as weeds into bushland is of greater management concern.

Variation in patterns of mating within and among plant populations can be impacted by habitat disturbance and have significant implications for offspring fitness. An understanding of this variation will inform predictions of seed genetic quality, benefiting ecological restoration through better seed-sourcing guidelines. We assessed mating system variation in six populations of tuart (Eucalyptus gomphocephala DC.), an iconic tree of significance to ecological restoration in Western Australia. A mixed mating system was observed with predominant outcrossing (tm = 0.76 ± 0.05) and low biparental inbreeding (tm–ts = 0.03 ± 0.02). We detected some evidence of increased inbreeding in a naturally fragmented population (tm–ts = 0.10 ± 0.04) and in a disturbed urban remnant (tm = 0.52 ± 0.12), including a family with complete selfing. However, most variation in outcrossing rate occurred among individuals within populations (82%), rather than among populations (2.6%) or among groups of populations defined by fragmentation or disturbance (15.4%). Genetic diversity was not consistently lower in offspring from fragmented, smaller and/or disturbed populations. These data reinforce the importance of sourcing seeds from multiple trees for ecological restoration, and emphasise that tuart’s mating system and the genetic diversity of offspring is robust to some habitat disturbance and/or fragmentation.

SUMMARY ‘Stalagmiform’ roots are here defined as dense, stalagmite-like aggregations of roots and rootlets which protrude from the sandy floor of certain limestone caves. Paper chromatography showed these structures were associated with large trees of Eucalyptus gomphocephala growing above the caves. They seem to form in response to localized abundance of water at sites beneath drip-points in the cave ceiling. The anatomy of ectomycorrhizal and non-infected stalagmiform rootlets was similar to that of Eucalypt rootlets. Non-pathogenic endophytes were also often present, giving many rootlets an endomycorrhizal character. This unusual combination of features places the stalagmiform root in a separate category from other specialized root structures.

Surface mining and quarrying profoundly affect landscapes and vegetation, so restoration of abandoned quarries attempts to create species-rich ecosystems for erosion control and fauna habitat. This study examined the success after 12 years of imported topsoil, sewage sludge, micronutrients, and fertiliser tablets applied at planting (all with and without broadcast fertiliser) on the survival, growth and health of six-month old seedlings of Eucalyptus gomphocephala, Acacia saligna, Banksia prionotes, B. attenuata, E. decipiens, Templetonia retusa and Dodonaea aptera in an abandoned limestone quarry in a mediterranean type climate in south-west Western Australia. Natural recruitment of seedlings of these species was also noted. After 12 years, overall survival was 17.4%, ranging from 42% in E. gomphocephala to 1% in T. retusa. Treatment combinations did not influence survival of any species, nor did growth (measured as height and DBHOB) vary in response to treatment. Treatment did not influence the health of any species significantly, with the exceptions of E. decipiens (healthiest in the All treatment) and B. attenuata (significantly lower levels of health when exposed to broadcast fertiliser). A. saligna, D. aptera and other local species from surrounding woodlands had naturally recruited seedlings. To date, although there is no evidence that any of the treatments tested is a panacea for success in re-establishing the study species in the medium-term, the study shows that vegetation native to the area can be re-established in abandoned limestone quarries at this site.