Adaptability and stability of novel eucalypt species and provenances across environments in Brazil at two assessment

The paucity of evidence on eucalypt browsing by common brushtail and common ringtail possums suggests that ringtails preferentially eat foliage from trees within the subgenus Monocalyptus. In contrast, brushtails eat less eucalypt foliage than do ringtails and prefer trees from the subgenus Symphyomyrtus. Trees from these subgenera differ in their defensive chemicals. Both contain tannins but it appears that only the symphyomyrts synthesise formylated phloroglucinol compounds (FPCs). We fed possums foliage from several individual Eucalyptus rossii and E. consideniana, both monocalypts, to avoid the confounding factor of FPCs, and examined the effects of blocking tannins by dipping foliage in polyethylene glycol (PEG). Ringtails and brushtails differed in their abilities to eat foliage from these eucalypts. The ringtails ate much more than did the brushtails and showed a small (about 10%) but significant increase in feeding in response to PEG. The brushtails were reluctant to eat foliage from either eucalypt species but doubled their intake when leaves were coated with PEG. Even so, they still did not eat enough to meet maintenance requirements for energy and nitrogen. Neither ringtails nor brushtails preferred foliage from any individual E. rossii tree, suggesting that all trees were equally defended. However, brushtails preferred foliage from some E. consideniana to others. Monocalypt tannins are clearly important barriers to feeding in brushtail possums, but further research with higher doses of PEG will confirm whether they are the only deterrent chemicals in monocalypt foliage.

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Interspecific Competition Between Eucalypt Seedlings

Australian Journal of Botany ◽

10.1071/bt9750225 ◽

1975 ◽

Vol 23 (2) ◽

pp. 225 ◽

Cited By ~ 5

Author(s):

JJ Burdon ◽

LD Pryor

Keyword(s):

Interspecific Competition ◽

Seedling Stage ◽

Eucalypt Species ◽

Physical And Chemical

Evidence from competition experiments in pots suggests that pairs of eucalypt species from the same association make almost the same use of the physical and chemical resources of the environment during the seedling stage. These results are discussed in relation to present theories concerning the coexistence of eucalypts in mixed associations.

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Development of Phytophthora cinnamomi Infection in Roots of Eucalypt Species Growing in a Soil That Suppresses Phytophthora Root Disease

Australian Journal of Botany ◽

10.1071/bt9830239 ◽

1983 ◽

Vol 31 (3) ◽

pp. 239 ◽

Cited By ~ 6

Author(s):

GC Marks ◽

IW Smith

Keyword(s):

Inner Core ◽

Phytophthora Cinnamomi ◽

Sandy Loam ◽

Seedling Survival ◽

Genetic Resistance ◽

Coarse Sand ◽

Root Disease ◽

Phenotypic Resistance ◽

Eucalypt Species ◽

Core Soil

When Eucalyptus sieberi was grown in either a steamed or unsteamed krasnozem that suppressed Phytophthora cinnamomi root rot and repotted when either 6 or 12 weeks old in a larger container of inoculated sandy loam, seedling survival was significantly greater in the unsteamed treatments. By varying the treatments in the inner core soil and outer inoculum jacket, substituting a biologically inert coarse sand in place of the krasnozem in the core, and using eucalypt species of varying disease tolerance while maintaining very strict hygiene conditions throughout these experiments, it was possible to either demonstrate or deduce that: (a) the seedlings were killed when infection spread into the major roots, root collar and lower stem; (b) the microflora in the unsteamed krasnozem appeared to slow down the decay process within the root, possibly when the fungus was attempting to establish itself within the root; (c) the phenotypic resistance of a seedling to root disease depended, inter alia, on its genetic resistance and on the microflora in the surrounding soil; (d) once the fungus was established in the suberized tissues the microflora in the external environment had no influence on disease.

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Role of the Seed Coat in Dormancy of Eucalyptuspauoiflora and E. Delegatensis Seeds

Australian Journal of Biological Sciences ◽

10.1071/bi9671237 ◽

1967 ◽

Vol 20 (6) ◽

pp. 1237 ◽

Cited By ~ 4

Author(s):

EP Bachelard

Keyword(s):

Gibberellic Acid ◽

Seed Coat ◽

Gaseous Exchange ◽

Eucalypt Species ◽

Phacelia Tanacetifolia

Gibberellic acid promotes the germination of dormant seeds of some eucalypt species including Eucalyptus pauciflora Sieb. and E. delegatensis R. T. Baker. It was suggested that gibberellic acid may stimulate germination by promoting enzymatic weakening of the seed coat (Bachelard 1967) as described for Phacelia tanacetifolia seeds (Chen and Thimann 1964). Previously, Grose (1963) suggested dormancy of of E. delegatensis seeds might be due to the seed coat limiting gaseous exchange.

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The importance of insects and lerp in the diet of juvenile regent honeyeaters, Xanthomyza phrygia: implications for the conservation of an endangered woodland bird

Wildlife Research ◽

10.1071/wr97078 ◽

1998 ◽

Vol 25 (4) ◽

pp. 409 ◽

Cited By ~ 12

Author(s):

Damon L. Oliver

Keyword(s):

Plant Species ◽

Resource Selection ◽

New South ◽

New South Wales ◽

The Other ◽

Conservation Strategies ◽

Eucalypt Species ◽

South Wales ◽

Breeding Seasons

The dietary items fed to regent honeyeater, Xanthomyza phrygia, nestlings and fledglings by adults were recorded in two consecutive breeding seasons in the Bundarra–Barraba region west of Armidale, New South Wales. Insects were the most common dietary items fed to juveniles (53% of identified items), followed by lerp (26.5%) and nectar (20.5%). Nestlings were fed mostly insects (58% of feeds), and carbohydrates (nectar and lerp) made up the rest of their diet. Fledglings, however, were fed mainly carbohydrates (nectar and lerp comprised 61.2% of all items) while protein from insects was the other major component of their diet. Males tended to feed juveniles more insects than did females, although there were no significant divisions of labour between parents in selecting dietary items for nestlings or fledglings. This study highlights the importance of insects and lerp in the diet of juvenile regent honeyeaters, and the diversity of plant species on which their parents foraged. The species shows a broader resource selection than was found in previous studies which considered the species to be highly nectarivorous and selective for a few key eucalypt species. The importance of insects and carbohydrates other than nectar in the diet of the regent honeyeater needs to be recognised in the development of conservation strategies for the species.

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