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1
Walters, Judi R., Tina L. Bell, and Steve Read. "Intra-specific variation in carbohydrate reserves and sprouting ability in Eucalyptus obliqua seedlings." Australian Journal of Botany 53, no. 3 (2005): 195. http://dx.doi.org/10.1071/bt04016.
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Seedlings of 13 provenances of Eucalyptus obliqua L’Hér. grown under favourable moisture and nutrient conditions in a glasshouse for 9 months showed significant differences in seedling height, lignotuber size and carbohydrate reserve pools in roots and lignotubers. Lignotuber size was strongly and inversely correlated with mean annual rainfall of the source provenance, and larger E. obliqua lignotubers had higher concentrations and pools of carbohydrate reserves than smaller lignotubers. When seedling stems were clipped just above the lignotuber to simulate grazing or damage by fire, clipped seedlings showed significantly different responses to disturbance; seedlings with large carbohydrate reserve pools produced more sprouts of greater dry weight than seedlings with small carbohydrate reserve pools. The sprouting ability of lignotubers was related to carbohydrate reserves, such that plants with larger reserves in the lignotubers and roots supported production of a greater number of sprouts of greater total biomass than plants with smaller reserves. These results suggest that the sprouting mechanism provided by lignotubers is more important for seedling survival in areas of lower rainfall.
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Walters, Judi R., Alan P. N. House, and David Doley. "Water and nutrient availabilities do not affect lignotuber growth and sprouting ability of three eucalypt species of south-eastern Queensland." Australian Journal of Botany 53, no. 3 (2005): 251. http://dx.doi.org/10.1071/bt04021.
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Shoot biomass and lignotuber size of seedlings of three eucalypt species, Eucalyptus acmenoides Schauer, E. siderophloia Benth. and Corymbia variegata [syn. E. maculata (F.Muell.) K.D.Hill and L.A.S.Johnson], were measured for glasshouse-grown seedlings established under two water and nutrient regimes. Seedlings were subjected to shoot removal (clipping) at ages from 9 to 19 weeks, and transferred to the high water treatment for a further 8 weeks to assess shoot emergence from lignotubers. Seedling shoot biomass was greater in both the high than the low nutrient and water treatments, but lignotuber diameter was not affected significantly. C. variegata seedlings had the largest lignotuber diameters, followed by E. siderophloia and E. acmenoides, respectively. Although growth of shoots was influenced by nutrient availability, results suggest that species differences in the growth of lignotubers was less affected. It is suggested that lignotuber growth was strongly influenced by genotype. More than 70% of C. variegata seedlings clipped at 9 weeks sprouted, compared with only 5 and 10% of seedlings of E. siderophloia and E. acmenoides, respectively. All C. variegata seedlings sprouted after being clipped at 19 weeks, but <80% of E. siderophloia and <60% of E. acmenoides sprouted when clipped at the same age. It was concluded that seedlings forming part of the regeneration stratum in dry sclerophyll forests need to be protected from damage for at least 4 months (for C. variegata) or at least 6 months (for E. siderophloia and E. acmenoides) if they are to survive by sprouting from lignotubers.
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Tyson, M., R. E. Vaillancourt, and J. B. Reid. "Determination of Clone Size and Age in a Mallee Eucalypt Using RAPDs." Australian Journal of Botany 46, no. 2 (1998): 161. http://dx.doi.org/10.1071/bt97003.
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Fragmentation of lignotubers and the consequent problems in genotype identification make demographic studies of mallee eucalypts unreliable. DNA fingerprinting using Random Amplification of Polymorphic DNA (RAPD) markers was employed to determine if a hybrid copse between Eucalyptus risdonii and E. amygdalina was clonal. Based on lignotuber morphology this copse appeared to be composed of approximately 20 separate individuals. No variation in RAPD genotype was observed for 67 bands scored from nine primers among the 20 individuals. In contrast, variation was observed between individuals sampled from outside the copse (average 28.6 band differences between any two individuals) and within full sibling families (average 12.9 band differences between individuals). On this basis the copse was considered to be clonal (one genet), originating from lignotuber fragmentation, and measured 5.5 × 3.5 m. The rate of radial expansion in 15-year-old seedling and lignotuber cohorts was measured and used to estimate the age of the hybrid copse. The hybrid genet appeared to be at least 900 years old. While such estimates must be viewed with caution they strongly support the suggestion that mallee eucalypts may attain ages far in excess of single-stemmed eucalypts.
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Whittock, S. P., L. A. Apiolaza, C. M. Kelly, and B. M. Potts. "Genetic control of coppice and lignotuber development in Eucalyptus globulus." Australian Journal of Botany 51, no. 1 (2003): 57. http://dx.doi.org/10.1071/bt02049.
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The economics of short-rotation pulpwood plantations of Eucalyptus globulus as a coppice crop are influenced by stump survival and subsequent coppice growth rates. This study revealed significant genetic diversity in coppicing traits, both within and between subraces, following felling in a progeny trial after 9 years of growth. A total of 67% of trees coppiced after 14 months, but subraces varied from 43 to 73%. Heritabilities for coppice success (0.07) and subsequent growth (0.16–0.17) were low but statistically significant. Strong genetic correlation between presence/absence of coppice, the number of stems coppicing from the stump and modal coppice height, indicate that selection is possible by using the binary trait. The ability of a tree to coppice was genetically correlated with tree growth prior to felling (rg = 0.61) and with nursery-grown seedling traits, where large genetic differences were observed in the development of lignotubers. Coppicing was genetically correlated with the number of nodes with lignotubers (rg = 0.66) and seedling stem diameter at the cotyledonary node (rg = 0.91). These traits were uncorrelated with later age growth and with each other. The results suggest that coppicing is influenced by three independent mechanisms—lignotuber development, enlargement of the seedling stem at the cotyledonary node and vigorous growth—which enhance ability to survive catastrophic damage, and indicate that both lignotuber and coppice development can be altered by both natural and artificial selection.
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Head, MJ, and CJ Lacey. "Radiocarbon Age-Determinations From Lignotubers." Australian Journal of Botany 36, no. 1 (1988): 93. http://dx.doi.org/10.1071/bt9880093.
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Large plate-like lignotubers formed by Eucalyptus botryoides Sm. were examined at a site on the south coast of New South Wales. Circumstantial evidence suggests that they are of great antiquity, yet 14C activity measurements of samples taken from lignotubers or associated stump wood corresponded to young ages, and it is clear that low durability of wood from these lignotubers prevents an accurate age determination by 14C dating methods. Ages of up to 600 years B.P. were obtained, but only from carbonised wood fragments associated with, but not connected to, decayed portions of large lignotubers. The differences in 14C activity found in samples from the intact lignotubers could not be interpreted clearly in terms of sequential growth periods for them. 14C activity differences between samples from two lignotubers are difficult to explain on the evidence available. Conversely, age sequences of up to 540 years were obtained from lignotubers of Eucalyptus coccifera Hook f., from Snug Tiers, near Hobart, Tasmania. The wood from these lignotubers has been well preserved. Possible reasons for these differences in lignotuber preservation will be discussed further.
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Myers, BA. "The Influence of the Lignotuber on Hydraulic Conductance and Leaf Conductance in Eucalyptus behriana Seedlings." Functional Plant Biology 22, no. 5 (1995): 857. http://dx.doi.org/10.1071/pp9950857.
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Hydraulic conductances of stem segments and stem-plus-lignotuber segments were estimated for 3-year-old seedlings of the mallee eucalypt Eucalyptus behriana F. Muell. Stems of seedlings were cut underwater and either above or below the lignotuber. Cutting the stem of intact seedlings underwater and above the lignotuber resulted in rapid increases in leaf water potential (Ψ); 1.1 MPa in 10-15 min with a concomitant decrease in leaf conductance. Cutting the stem below the lignotuber did not significantly affect leaf Ψ or leaf conductance. Transpirational flow through whole seedlings and segments of seedlings was about 10-9 m3 s-1. The hydraulic conductance of the lignotuber (2.27 × 10-9 m3 s-1 Mpa-1) was about half that of the stem. This work suggests that resistance to water flow through the lignotuber accounts, in part, for the persistently low dawn Ψ of the foliage of mature trees of E. behriana.
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Goodger, Jason Q. D., Allison M. Heskes, Drew J. King, Roslyn M. Gleadow, and Ian E. Woodrow. "Research note: Micropropagation of Eucalyptus polybractea selected for key essential oil traits." Functional Plant Biology 35, no. 3 (2008): 247. http://dx.doi.org/10.1071/fp07241.
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A protocol for the micropropagation of Eucalyptus polybractea R.T. Baker (blue mallee) using axillary bud proliferation from lignotuber-derived explants is described. Three different ages of plants were used as explant sources: glasshouse-grown seedlings, field-grown saplings, and coppice of field-grown mature lignotubers. Explants from each source initiated successfully and no significant difference was observed for shoot proliferation, rooting success or hardening success between explant sources. Leaf oil quantity and quality for hardened clones transplanted to a field plantation were assessed after 3 months of growth. Ramets of all clones contained high quality oil with over 80% 1,8-cineole. For seedling-derived clones, foliar oil concentrations of ramets were higher than those of the ortets from which they were derived. For sapling and mature lignotuber derived clones the opposite was the case. This suggests that ontogenetic and physiological constraints may be influencing yield in the young ramets. The age of the explant source did not appear to influence the success of micropropagation, and as a result older plants (for which key oil traits are known) can be selected as elite plants for multiplying selected genotypes via micropropagation.
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Pickering, Catherine Marina, and Kristy Barry. "Size/age distribution and vegetative recovery of Eucalyptus niphophila (snowgum, Myrtaceae) one year after fire in Kosciuszko National Park." Australian Journal of Botany 53, no. 6 (2005): 517. http://dx.doi.org/10.1071/bt04117.
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Size/age distribution and vegetative regeneration were examined for 50 Eucalyptus niphophila Maiden & Blakely trees in each of eight subalpine sites in Kosciuszko National Park 1 year after the January–February 2003 bushfires. Trees sampled were generally large and mature, with an average of 2.5 trunks, lignotuber diameter of 54 cm and largest trunk diameter of 18 cm, with a few larger trees at all sites. Converting the girth of largest trunk into rough age estimates by using an existing regression formula gave an approximate minimum (~29 years), maximum (~186 years), median (~58 years) and average age of ~64 years (error of ~15 years). For trees with trunks after fire, 96.5% had lost all existing leaves. Nearly all trees (95%) had shoots from the lignotuber, but only 4.25% of trees had also epicormic shoots on trunks and stems. Size/age were related to some but not all measures of regeneration. In the future, existing trunks could senesce, with nearly all regrowth from the lignotubers. This could result in a change from open woodlands with large/old trees with a few trunks to closed woodlands of lower-growing trees with a mallee form.
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Abbott, I. "Rate of Growth of Banksia grandis Willd. (Proteaceae) in Western Australian Forest." Australian Journal of Botany 33, no. 4 (1985): 381. http://dx.doi.org/10.1071/bt9850381.
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Banksia grandis is a major understorey component of the jarrah forest and is a refuge of the soil fungus Phytophthora cinnamomi which kills many native plant species and threatens timber production. This paper presents data on the rate of growth of the lignotuber, shoot and stem of B. grandis. Length of the seedling lignotuber increased 0.23 cm year-1 over 3 years, that of saplings and trees increased 0.44 cm yea-1. The period for a seedling to attain 1.3 m height was calculated as c. 15 years. Short-term diameter increment of trees averaged 0.19-0.27 cm year-1, indicating that diameter at breast height of 20 cm should be attained in c. 80-100 years; this estimate is also supported by direct and indirect long- term data. Watering, shading and spraying with insecticide had no significant influence on height growth of saplings. Four years after fire, sapling coppice from large lignotubers nearly attained the height of the plant before the fire. Trees, but not saplings, grew faster after logging of forest. The significance of these growth rates is discussed in relation to two methods (mechanical removal, moderate-intensity fire) proposed to reduce the abundance of B. grandis in the jarrah forest.
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Evans, Rodger C., and Sam P. Vander Kloet. "Comparative analysis of hypocotyl development in epiphytic, lignotuber-forming, and terrestrial Vaccinieae (Ericaceae)." Botany 88, no. 6 (June 2010): 556–64. http://dx.doi.org/10.1139/b10-031.
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A comparative analysis of hypocotyl development was undertaken with seedlings of three Vaccinieae (Ericaceae) species ( Macleania pentaptera Hoerold, Macleania rupestris (Kunth) A.C. Sm., and Vaccinium angustifolium Ait.) to determine the developmental basis for enlarged hypocotyls leading to the development of woody tubers (lignotubers) in M. pentaptera and M. rupestris. Differences in hypocotyl development are apparent after the first true leaves are visible in each species. Vascular tissue in M. rupestris and V. angustifolium is composed primarily of axial columns of secondary xylem. Secondary xylem tissues in M. pentaptera remain mostly parenchymatous and form radial columns of cells through numerous periclinal divisions. Furthermore, the secondary xylem of M. pentaptera comprises random networks of interconnected, small xylem elements in comparison with the secondary xylem of M. rupestris and V. angustifolium. These differences in hypocotyl development persist through the first 200 d of hypocotyl development, and ultimately lead to the development of a large lignotuber in M. pentaptera. Given the large amounts of parenchymatous tissue, a secondary xylem of relatively short secondary xylem elements, and the absence of adventitious buds, we propose that the lignotubers of M. pentaptera are used for short term water storage, rather than regeneration.
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Auld, TD. "The Survival of Juvenile Plants of the Resprouting Shrub Angophora hispida (Myrtaceae) After a Simulated Low Intensity Fire." Australian Journal of Botany 38, no. 3 (1990): 255. http://dx.doi.org/10.1071/bt9900255.
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Nine-year-old juvenile plants of Angophora hispida (Smith) Blaxell, established in heathland after fire, were subjected to three treatments: stem clipped at base; stem clipped at base combined with burning at low intensity; or no treatment (control). In all, 93% of control plants survived over the 20-month sampling period; 80% of clipped plants and 37% of clipped and burnt plants resprouted. Under the latter treatment, size and depth of burial of the developing lignotuber interacted to influence the degree of plant survival. Only plants with lignotubers greater than 5000 mm³ in volume showed no mortality while, on average, plants at or above ground level showed greater mortality than those below ground.
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Walker, J., CH Thompson, and CJ Lacey. "Morphological Differences in Lignotubers of Eucalyptus intermedia R.T. Bak. And E. signata F. Muell. Associated With Different Stages of Podzol Development on Coastal Dunes, Cooloola, Queensland." Australian Journal of Botany 35, no. 3 (1987): 301. http://dx.doi.org/10.1071/bt9870301.
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The sandmass at Cooloola comprises a series of overlapping aeolian dune systems that extend in age from the present back more than 100 000 years. Podzols are the dominant soils, forming a sequence from rudimentary through to giant forms, according to age. The lignotuber morphology of Eucalyptus signata and E. intermedia was examined within each dune system across the chronosequence, at sites in which most factors affecting plant growth (available soil water status, drainage, light, temperature, fire regimes, exposure to wind and/or salt spray) other than a declining soil nutrient supply were similar. Three lignotuber morphologies were identified: (1) a single-stemmed (SS) form; (2) a multi-stemmed (MS) form with stems originating from a lignotuber only slightly larger than a main stem; and (3) a multi-stemmed plate-like form (MSP) with individual stems separated and growing from a plate-like lignotuber. Multi-stemmed forms of the two eucalypts occur along the coastal margin and on the most nutrient- poor dunes; at all other sites single-stemmed forms are dominant. The most nutrient-poor site had only MS and MSP forms, whilst in sheltered areas the coastal margin had SS individuals. We conclude that in the Cooloola sandmass the development of multi-stemmed forms in both E. signata and E. intermedia may be induced by a variety of factors, including very low nutrient status, but the multi-stemmed plate-like form of E. intermedia is most likely a response to an exceptionally low nutrient supply.
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Burrows, G. E. "Buds, bushfires and resprouting in the eucalypts." Australian Journal of Botany 61, no. 5 (2013): 331. http://dx.doi.org/10.1071/bt13072.
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Eucalypts encounter a wide range of severe disturbances such as extensive defoliation by insects, major structural damage from cyclonic winds, as well as foliage and bark loss during drought and fire. Most healthy, mature eucalypts are not killed by these events, but regenerate vegetatively. With increasing intensity of disturbance, resprouting first occurs from the accessory buds in the small-diameter branchlets of the crown, followed by the epicormic buds in the medium- and large-diameter branches and stems, and then from the buds of the lignotuber. All these modes of regeneration are ultimately dependent on preventitious buds and, thus, the present review concentrates on axillary buds, their subsequent development into epicormic or lignotuber buds and their degree of protection from fire. The eucalypts have remarkably abundant, well protected and anatomically distinctive bud-forming structures in their leaf axils, branches, stems and lignotubers. These structures are quite consistent across this large genus, but are generally different from resprouting structures in many other plants. From an anatomical perspective, these structures seem best adapted to regeneration after fire, rather than damage from insects, storms or drought and this also correlates with ecological observations. On a worldwide basis, the eucalypts are some of the most successful post-fire resprouters, especially epicormic resprouting after medium- and high-intensity fires. Given the apparent ecological advantages of epicormic resprouting (the rapid reestablishment of extensive leaf area while simultaneously shading basal resprouters and seedlings) this could be an important factor in the success of eucalypts in Australia. Recent phylogenetic analysis has indicated a long relationship between eucalypts, fire and bud structures that facilitate resprouting.
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Wirthensohn, M. G., and M. Sedgley. "Effect of pruning on regrowth of cut foliage stems of seventeen Eucalyptus species." Australian Journal of Experimental Agriculture 38, no. 6 (1998): 631. http://dx.doi.org/10.1071/ea98053.
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Summary. Seventeen species of Eucalyptus were subjected to trials investigating their suitability for floriculture and the effect of pruning on cut foliage production. There was variation in leaf colour within and between species, and in the time to phase change and flowering. There were significant differences at 16 months between species for tree height, trunk diameter and lignotuber diameter with E. globulus having the largest dimensions. Following pruning at 19 months, there was an initial significant interaction between species and pruning height in relation to tree height, height increment, and trunk and lignotuber diameter. After 1 year there were significant differences between species, in the length of stems, number of stems and total weight of stems, with E. globulus producing the highest number and weight of stems. There was a positive correlation of trunk diameter and lignotuber diameter at 3 and 6 months after pruning with the number of cut foliage stems produced at 12 months. For E. gunnii pruning to 1.0 m at 25 months produced the most stems at 6 months after pruning.
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Nicolle, Dean. "A classification and census of regenerative strategies in the eucalypts (Angophora, Corymbia and Eucalyptus—Myrtaceae), with special reference to the obligate seeders." Australian Journal of Botany 54, no. 4 (2006): 391. http://dx.doi.org/10.1071/bt05061.
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A survey of regenerative strategies in the eucalypts, including lignotuber development, was undertaken by extensive field observations, seedling trials and trials of cultivated individuals over a 12-year period. Four broad regenerative strategies were identified, viz. obligate seeders, lignotuber sprouters, stem sprouters and combination sprouters. These four regenerative strategies are based on the ability to develop a lignotuber and the regeneration strategy after whole-crown destruction. These regenerative strategies do not wholly correspond to the tree, mallee, mallet, marlock and shrub habit categories commonly applied to eucalypts. The obligate seeders include many more terminal taxa than have been previously documented as mallet taxa, with 78 western obligate seeders (the ‘true’ mallets) and nine eastern obligate seeders listed herein. Obligate seeders do not possess a lignotuber and are killed by crown-destructive events, and as such are relatively short-lived in most natural environments. A further 16 taxa are also known to be non-lignotuberous, but these are capable of producing epicormic regrowth from the trunk following crown destruction and are defined as stem sprouters. The remaining two regenerative strategies include taxa that are both lignotuberous and able to regenerate vegetatively following disturbance events. The persistent and conjecturous mallet–marlock–moort distinction is rejected, this study showing it to be dependent on stand density. Data presented indicate no significant difference in germination time or maturation time between western obligate-seeder taxa and closely related sprouter taxa. The conservation status of obligate-seeder taxa is discussed. Nomenclatural issues regarding the taxonomic distinction between obligate-seeder and resprouter sister taxa are discussed. A census of regenerative strategies for all recognised eucalypt taxa is included as an accessory publication on the web.
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Stimpson, Margaret Leith, JEREMY J. BRUHL, and PETER H. WESTON. "Could this be Australia’s rarest Banksia? Banksia vincentia (Proteaceae), a new species known from fourteen plants from south-eastern New South Wales, Australia." Phytotaxa 163, no. 5 (March 31, 2014): 269. http://dx.doi.org/10.11646/phytotaxa.163.5.3.
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Possession of hooked, distinctively discolorous styles, a broadly flabellate common bract subtending each flower pair, and a lignotuber place a putative new species, Banksia sp. Jervis Bay, in the B. spinulosa complex. Phenetic analysis of individuals from all named taxa in the B. spinulosa complex, including B. sp. Jervis Bay, based on leaf, floral, seed and bract characters support recognition of this species, which is described here as Banksia vincentia M.L.Stimpson & P.H.Weston. Known only from fourteen individuals, B. vincentia is distinguished by its semi-prostrate habit, with basally prostrate, distally ascending branches from the lignotuber, and distinctive perianth colouring. Its geographical location and ecological niche also separate it from its most similar congeners.
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Costa e Silva, João, Brad Potts, Peter A. Harrison, and Tanya Bailey. "Temperature and Rainfall Are Separate Agents of Selection Shaping Population Differentiation in a Forest Tree." Forests 10, no. 12 (December 14, 2019): 1145. http://dx.doi.org/10.3390/f10121145.
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Research highlights: We present evidence indicating that covariation of functional traits among populations of a forest tree is not due to genetic constraints, but rather selective covariance arising from local adaptation to different facets of the climate, namely rainfall and temperature. Background and Aims: Traits frequently covary among natural populations. Such covariation can be caused by pleiotropy and/or linkage disequilibrium, but also may arise when the traits are genetically independent as a direct consequence of natural selection, drift, mutation and/or gene flow. Of particular interest are cases of selective covariance, where natural selection directly generates among-population covariance in a set of genetically independent traits. We here studied the causes of population-level covariation in two key traits in the Australian tree Eucalyptus pauciflora. Materials and Methods: We studied covariation in seedling lignotuber size and vegetative juvenility using 37 populations sampled from throughout the geographic and ecological ranges of E. pauciflora on the island of Tasmania. We integrated evidence from multiple sources: (i) comparison of patterns of trait covariation within and among populations; (ii) climate-trait modelling using machine-learning algorithms; and (iii) selection analysis linking trait variation to field growth in an arid environment. Results: We showed strong covariation among populations compared with the weak genetic correlation within populations for the focal traits. Population differentiation in these genetically independent traits was correlated with different home-site climate variables (lignotuber size with temperature; vegetative juvenility with rainfall), which spatially covaried. The role of selection in shaping the population differentiation in lignotuber size was supported by its relationship with fitness measured in the field. Conclusions: Our study highlights the multi-trait nature of adaptation likely to occur as tree species respond to spatial and temporal changes in climate.
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Graham, A. W., M. A. Wallwork, and M. Sedgley. "Lignotuber Bud Development in Eucalyptus cinerea (F. Muell. ex Benth)." International Journal of Plant Sciences 159, no. 6 (November 1998): 979–88. http://dx.doi.org/10.1086/314091.
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Canadell, J., and L. López-Soria. "Lignotuber reserves support regrowth following clipping of two Mediterranean shrubs." Functional Ecology 12, no. 1 (February 1998): 31–38. http://dx.doi.org/10.1046/j.1365-2435.1998.00154.x.
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Shepherd, Mervyn, Peter Pomroy, Mark Dieters, and David Lee. "Genetic control of propagation traits in a single Corymbia torelliana × Corymbia variegata family." Canadian Journal of Forest Research 37, no. 12 (December 2007): 2563–74. http://dx.doi.org/10.1139/x07-111.
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Genetic control of vegetative propagation traits was described for a second-generation, outbred, intersectional hybrid family (N = 208) derived from two species, Corymbia torelliana (F. Muell.) K.D. Hill & L.A.S. Johnson and Corymbia variegata (F. Muell.) K.D. Hill & L.A.S. Johnson, which contrast for propagation characteristics and in their capacity to develop lignotubers. Large phenotypic variances were evident for rooting and most other propagation traits, with significant proportions attributable to differences between clones (broad-sense heritabilities 0.2–0.5). Bare root assessment of rooting rate and root quality parameters tended to have the highest heritabilities, whereas rooting percentage based on root emergence from pots and shoot production were intermediate. Root biomass and root initiation had the lowest heritabilities. Strong favourable genetic correlations were found between rooting percentage and root quality traits such as root biomass, volume, and length. Lignotuber development on a seedling was associated with low rooting and a tendency to poor root quality in cuttings and was in accord with the persistence of species parent types due to gametic phase disequilibrium. On average, nodal cuttings rooted more frequently and with higher quality root systems, but significant cutting type × genotype interaction indicated that for some clones, higher rooting rates were obtained from tips. Low germination, survival of seedlings, and rooting rates suggested strong hybrid breakdown in this family.
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Cruz, Alberto, and José M. Moreno. "Lignotuber size of Erica australis and its relationship with soil resources." Journal of Vegetation Science 12, no. 3 (February 24, 2001): 373–84. http://dx.doi.org/10.2307/3236851.
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Gosper, Carl R., Tara Hopley, Margaret Byrne, Stephen D. Hopper, Suzanne M. Prober, and Colin J. Yates. "Phylogenomics shows lignotuber state is taxonomically informative in closely related eucalypts." Molecular Phylogenetics and Evolution 135 (June 2019): 236–48. http://dx.doi.org/10.1016/j.ympev.2019.03.016.
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Ferreira, M. I., N. Conceição, T. S. David, and N. Nadezhdina. "ROLE OF LIGNOTUBER VERSUS ROOTS IN THE WATER SUPPLY OF RAINFED OLIVES." Acta Horticulturae, no. 991 (May 2013): 181–88. http://dx.doi.org/10.17660/actahortic.2013.991.22.
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Molinas, M. L., and D. Verdaguer. "LIGNOTUBER ONTOGENY IN THE CORK-OAK (QUERCUS SUBER; FAGACEAE) I. LATE EMBRYO." American Journal of Botany 80, no. 2 (February 1993): 172–81. http://dx.doi.org/10.1002/j.1537-2197.1993.tb13786.x.
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Cruz, Alberto, Beatriz Perez, and Jose M. Moreno. "Resprouting of the Mediterranean-type shrub Erica australis with modified lignotuber carbohydrate content." Journal of Ecology 91, no. 3 (June 2003): 348–56. http://dx.doi.org/10.1046/j.1365-2745.2003.00770.x.
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Conran, JG, and HT Clifford. "Variation in Banksia oblongifolia Cav. (Proteaceae)." Brunonia 10, no. 2 (1987): 177. http://dx.doi.org/10.1071/bru9870177.
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Banksia oblongifolia Cav. is presently regarded as a variable species. The variation, however, appears to be discontinuous, thereby permitting the rec- ognition of two taxa differing in seedling and adult morphology and ecology. Differences are reported between these taxa in plant height, leaf length, branch length, stem number, seed set and shape, as observed for populations growing in the field, and cotyledon length, leaf length, plant height and lignotuber development, under cultivation. A new varietal combination, Banksia oblongifolia var. minor (Maiden & Camfield) Conran & Cliff, is recognised and circumscribed for one of the taxa. Banksia oblongifolia var. oblongifolia is redefined. The relationships between the two taxa are discussed.
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Molinas, M. L., and D. Verdaguer. "LIGNOTUBER ONTOGENY IN THE CORK-OAK (QUERCUS SUBER; FAGACEAE) II. GERMINATION AND YOUNG SEEDLING." American Journal of Botany 80, no. 2 (February 1993): 182–91. http://dx.doi.org/10.1002/j.1537-2197.1993.tb13787.x.
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Mibus, R. "Early Lignotuber Formation in Banksia—Investigations into the Anatomy of the Cotyledonary Node of TwoBanksia (Proteaceae) Species." Annals of Botany 86, no. 3 (September 2000): 575–87. http://dx.doi.org/10.1006/anbo.2000.1219.
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Fensham, RJ, and DMJS Bowman. "Stand Structure and the Influence of Overwood on Regeneration in Tropical Eucalypt Forest on Melville-Island." Australian Journal of Botany 40, no. 3 (1992): 335. http://dx.doi.org/10.1071/bt9920335.
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The stand structure of tree species in tropical eucalypt forest on Melville Island reveals a mass of short woody sprouts in the ground layer and low numbers of sapling eucalypts. The growth of the woody sprouts showed no significant response in the first 2 years after release from overwood competition. However, eucalypts are released in response to overwood removal, after 2-5 years, although investigations of old clear-felled blocks indicated that this response is not consistent. The initiation of saplings may be related to the size of the lignotuber and the presence of a tap root for some species. It is suggested that the accession of saplings may be limited by the degradation of root systems by termite herbivory. Using assumptions regarding longevity of life stages, it is demonstrated that the forest structure of the study site can be perpetuated undercurrent conditions despite indications that the relative dominance of the forest eucalypt species will shift.
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McDonald, M. W., M. I. H. Brooker, and P. A. Butcher. "A taxonomic revision of Eucalyptus camaldulensis (Myrtaceae)." Australian Systematic Botany 22, no. 4 (2009): 257. http://dx.doi.org/10.1071/sb09005.
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Eucalyptus camaldulensis Dehnh. has one of the widest natural distributions of any Australian tree species. It is represented in most climatic zones and the majority of river systems across Australia. Numerous studies have documented morphological and genotypic variation among populations from across its range. Its adaptation to a wide range of environments has contributed to it becoming one of the most widely cultivated eucalypts across a range of arid, temperate and tropical countries. A recent range-wide study of E. camaldulensis with microsatellite markers concluded that its patterns of genetic variation were consistent with it comprising seven infraspecific taxa. As foreshadowed in that study, here we describe these taxa, viz. subsp. acuta, subsp. arida, subsp. camaldulensis, subsp. minima, subsp. obtusa, subsp. refulgens and subsp. simulata. A key to subspecies is presented, with each subspecies being illustrated and the main differences tabulated. Operculum shape, the arrangement of stamens in the bud and the reticulation density of adult leaves are some of the main characters distinguishing taxa. Clustering patterns from further analyses of the microsatellite data were consistent with morphological affinities among subspecies. Typification issues and lignotuber status are among topics discussed.
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Myers, BA, M. Kuppers, and TF Neales. "Effect of Stem Excision Under Water on Bulk Leaf Water Potential, Leaf Conductance, CO2 Assimilation and Stemwood Water Storage in Eucalyptus behriana F. Muell." Functional Plant Biology 14, no. 2 (1987): 135. http://dx.doi.org/10.1071/pp9870135.
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Cutting the stem, under water and above the lignotuber, of intact trees of Eucalyptus behriana caused rapid increases in the bulk leaf water potential (Ψ) in the canopy above. In eight separate experiments the mean increase in Ψ of 3.1 MPa in 1 h was associated with rapid and persistent decreases in leaf conductance (g), which have been ascribed to hydropassive changes in leaf turgor. The water content of the stemwood increased by 1.8-2.0% as the bulk water potential increased by approximately 2.5 MPa. In the first hour after cutting the stems under water, the observed rate of water uptake by the cut stem was approximately six times the estimated transpiration rate of the leaves. This discrepancy is attributed to an increase in stem water content. The specific capacitance of the stemwood was estimated to be 0.008 g g-1 (dry weight) Mpa-1. The quantity of water available from storage in the stem was estimated to be less than 0.1 mm. Continuous measurements of gas exchange on a leaf before, during and after stem-cutting showed that CO2 assimilation decreased in parallel with g, but in a manner that caused increases in intercellular CO2 concentration. This indicated that the rapid increases of bulk leaf turgor, induced by stem-cutting, affected photosynthetic capacity.
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Abbott, I. "Recruitment and Mortality in Populations of Banksia grandis Willd. In Western Australian Forest." Australian Journal of Botany 33, no. 3 (1985): 261. http://dx.doi.org/10.1071/bt9850261.
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This paper examines seed release and seed dispersal; recruitment in relation to fire and logging; mortality of seedlings in relation to their age; and the dynamics of one population from November 1979 to March 1983. Dehiscence of follicles is caused by wetting and drying of the infructescence, so that most seeds fall to the ground during autumn in the Mediterranean climate of south-western Australia. Seeds are wind- dispersed, settling downward from the parent tree: 90% of seed falls within the first year. There is large variation in annual recruitment of seedlings, reflecting large annual differences in the number of infructescences produced. Fires of various intensities or logging do not enhance recruitment. Seedling mortality is greatest during the first summer after germination; this may be related to the rudimentary development of the lignotuber. A population of 1890 individually marked plants was studied for 3.5 years. Over twice as many deaths took place in summer and autumn as in winter and spring, and 90% of deaths were of plants less than 20 cm tall. At the conclusion of the study, total population size, through recruitment of three cohorts of seedlings, had increased by 7%. This indicates how important control of reproduction would be in achieving long-term reduction in the abundance of B. grandis, which harbours the pathogenic fungus Phytophthora cinnamomi.
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Pannell, JR, and PJ Myerscough. "Canopy-Stored Seed Banks of Allocasuarina distyla and A. nana in Relation to Time Since Fire." Australian Journal of Botany 41, no. 1 (1993): 1. http://dx.doi.org/10.1071/bt9930001.
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Aspects of the serotinous seed banks of Allocasuarina distyla (Vent.) L. Johnson and A. nana (Sieb. ex Spreng.) L. Johnson are presented in relation to fire. A. distyla is single-stemmed and fire-sensitive; A. nana resprouts multiple stems from a lignotuber following fire. Vegetative above-ground plant growth correlates with seed bank size in A. distyla better than in A. nana. There is approximately 10 times the canopy-stored seed in A. nana 8 years after fire than in A. distyla 9 years after fire. The critical period to initial seed set in A. distyla is between about 7 and 9 years. In A. nana, this period is typically longer but appears to depend on the age of the seed-producing genets. The age structure of the seed banks in both species remains more or less constant in time, with most seed being young. Seed viability declines in A. distyla from an initial 60% to less than 10% within about 12 years after seed set. A similar pattern appears likely for A. nana, although initial seed viability is about 40%. Attrition in seed viability is attributed to seed predation by insects, fungal attack and seed senescence. The dynamics of seed production and survivorship appear to be similar to those in serotinous proteaceous species studied to date.
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Strydom, Tiaan, Tineke Kraaij, Mark Difford, and Richard M. Cowling. "Fire severity effects on resprouting of subtropical dune thicket of the Cape Floristic Region." PeerJ 8 (June 10, 2020): e9240. http://dx.doi.org/10.7717/peerj.9240.
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It has been hypothesised that high-intensity fires prevent fire-dependent fynbos from being replaced by fire-avoiding subtropical thicket on dune landscapes of the Cape Floristic Region (CFR). Recent extensive fires provided an opportunity to test this hypothesis. We posit that (1) fire-related thicket shrub mortality would be size dependent, with smaller individuals suffering higher mortality than larger ones; and (2) that survival and resprouting vigour of thicket shrubs would be negatively correlated with fire severity. We assessed survival and resprouting vigour post-fire in relation to fire severity and pre-fire shrub size at two dune landscapes in the CFR. Fire severity was scored at the base of the shrub and categorised into four levels. Pre-fire size was quantified as an index of lignotuber diameter and stem count of each shrub. Resprouting vigour consisted of two variables; resprouting shoot count and resprouting canopy volume. A total of 29 species were surveyed. Post-fire survival of thicket was high (83–85%). We found that smaller shrubs did have a lower probability of post-fire survival than larger individuals but could detect no consistent relationship between shrub mortality and fire severity. Fire severity had a positive effect on resprouting shoot count but a variable effect on resprouting volume. Pre-fire size was positively related to survival and both measures of resprouting vigour. We conclude that thicket is resilient to high-severity fires but may be vulnerable to frequent fires. Prescribed high-intensity fires in dune landscapes are unlikely to reduce the extent of thicket and promote fynbos expansion.
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Prior, L. D., D. Eamus, and G. A. Duff. "Seasonal and Diurnal Patterns of Carbon Assimilation, Stomatal Conductance and Leaf Water Potential in Eucalyptus tetrodonta Saplings in a Wet - Dry Savanna in Northern Australia." Australian Journal of Botany 45, no. 2 (1997): 241. http://dx.doi.org/10.1071/bt96017.
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Seasonal and diurnal trends in carbon assimilation, stomatal conductance and leaf water potential were studied using 1–3 m tall saplings of Eucalyptus tetrodonta (F.Muell.). The study site was in an unburnt savanna near Darwin, where rainfall is strongly seasonal. Mean daily maximum assimilation rates ranged from 14.5 µmol m-2 s-1 in May to 4.8 µmol m-2 s-1 in October. There was a linear relationship between daily maximum assimilation rates and pre-dawn leaf water potential (r = 0.62, n = 508) and a log–log linear relationship between daily maximum stomatal conductance and pre-dawn leaf water potential (r = 0.68, n = 508). Assimilation rates and stomatal conductance were always higher in the morning than in the afternoon, irrespective of season. Stomatal conductance responded more strongly to leaf-to-air vapour pressure difference when pre-dawn leaf water potentials were moderately low (–0.5 to –1.5 MPa) than when they were very low (< –1.5 MPa) or high (> –0.5 MPa). Assimilation decreased sharply when temperature exceeded 35˚C. Seasonal trends in assimilation rate could be attributed primarily to stomatal closure, but diurnal trends could not. High leaf temperatures were a major cause of lower assimilation rates in the afternoon. Approximately 90% of leaves were lost by the end of the dry season, and above-ground growth was very slow. It is hypothesised that E. tetrodonta saplings allocate most photosynthate to root and lignotuber growth in order to tolerate seasonal drought and the high frequency of fire in northern Australian savannas.
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Burrows, W. H., M. B. Hoffmann, J. F. Compton, P. V. Back, and L. J. Tait. "Allometric relationships and community biomass estimates for some dominant eucalypts in Central Queensland woodlands." Australian Journal of Botany 48, no. 6 (2000): 707. http://dx.doi.org/10.1071/bt99066.
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Allometric equations are presented relating stem circumference to branch, leaf, trunk, bark, total above-ground and lignotuber biomass for Eucalyptus crebra F.Muell. (woodland trees), E. melanophloia Sol. Ex Gaerth. (both woodland and regrowth community trees) and E. populnea F.Muell. (woodland trees). There were no significant differences (P > 0.05) between the slopes of individual lognormal regression lines plotting stem circumference against total above-ground biomass for E. crebra, E. melanophloia and E. populnea. Root-to-shoot ratios and leaf area indices were also determined for the stands contributing to each regression. The regressions were then applied to measured eucalypt stems in the associated plant community to give estimates of each stand’s component (eucalypt tree fraction only) biomass per hectare. These eucalypt regressions were next applied to measured stems of each species on a total of 33 woodland sites in which these eucalypts individually contributed > 75% of total site basal area. Above-ground biomass/basal area relationships averaged 6.74 0.29 t m–2 basal area for 11 E. crebra sites, 5.11 0.28 t m–2 for 12 E. melanophloia sites and 5.81 0.11 t m–2 for 10 E. populnea sites. The mean relationship for all sites was 5.86 0.18 t m–2 basal area. The allometric relationships presented at both individual tree and stand levels, along with calculated biomass : basal area relationships, enable ready estimates to be made of above-ground biomass (carbon stocks) in woodlands dominated by these eucalypts in Queensland, assuming individual stem circumferences or community basal areas are known. However, to document changes in carbon stocks (e.g. for Greenhouse Gas Inventory or Carbon Offset trading purposes), more attention needs to be placed on monitoring fluxes in the independent variables (predictors) of these allometric equations.
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Paula, Susana, Paulette I. Naulin, Cristian Arce, Consttanza Galaz, and Juli G. Pausas. "Lignotubers in Mediterranean basin plants." Plant Ecology 217, no. 6 (November 5, 2015): 661–76. http://dx.doi.org/10.1007/s11258-015-0538-9.
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Fensham, R. J., R. J. Fairfax, and Y. M. Buckley. "An experimental study of fire and moisture stress on the survivorship of savanna eucalypt seedlings." Australian Journal of Botany 56, no. 8 (2008): 693. http://dx.doi.org/10.1071/bt08152.
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Eucalyptus melanophloia and E. populnea dominate large areas of savanna in eastern Australia. Under aboriginal management, fires probably occurred under a broad range of conditions, but under pastoral management, burning is avoided when soil moisture is low. This experiment subjected E. melanophloia and E. populnea seedlings to burning and moisture stress, to examine whether this change in burning regime could affect seedling survivorship. The findings suggest survivorship rates are 87–93% for unstressed seedlings with relatively large lignotubers (>12 mm2 plan area) and 56–66% for unstressed seedlings with small lignotubers. There was no substantial interactive effect between moisture stress and burning for E. melanophloia, but such an interaction was apparent for E. populnea, such that moisture stress multiplied the effect of burning. The timing of burning in relation to soil-moisture conditions may have an enduring effect on woodland structure where E. populnea is dominant. E. melanophloia seedlings are more resistant to burning, especially with moisture stress, and fire may not be limiting structural development in woodlands where this species dominates. However, a more detailed understanding of species demography is required, including the conditions required for germination, causes of seedling mortality and the time taken for seedlings to develop fire resistance in the field.
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Wooller, S. J., and R. D. Wooller. "Seed set in two sympatric banksias, Banksia attenuata and B. baxteri." Australian Journal of Botany 49, no. 5 (2001): 597. http://dx.doi.org/10.1071/bt00084.
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Two species of banksia, studied on the south coast of Western Australia, flowered simultaneously and had floral characteristics often associated with vertebrate pollination. The pollen of both was carried by honeyeater birds and small mammals (honey possums). Despite this, differential exclusion of vertebrates and invertebrates from inflorescences indicated that Banksia attenuata set substantial quantities of seed when visited only by invertebrates, although seed set increased with the addition of vertebrate visitors. Banksia baxteri set much seed in the absence of any animal visitors and seed set increased with invertebrate, but not vertebrate, visitation. We suggest that these differences in pollination strategies reflect regeneration by B. baxteri solely from canopy seeds released after fire, whereas B. attenuata also regenerates from seeds released between fires, as well as from lignotubers and epicormic buds.
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Fallas-Cedeño, Lottie, N. Michele Holbrook, Oscar J. Rocha, Nelly Vásquez, and Marco V. Gutiérrez-Soto. "Phenology, Lignotubers, and Water Relations of Cochlospermum vitifolium, a Pioneer Tropical Dry Forest Tree in Costa Rica." Biotropica 42, no. 1 (July 20, 2009): 104–11. http://dx.doi.org/10.1111/j.1744-7429.2009.00539.x.
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Dell, B., S. Jones, and I. M. Wallace. "Phosphorus accumulation by lignotubers of jarrah (Eucalyptus marginata Donn ex Sm.) seedlings grown in a range of soils." Plant and Soil 86, no. 2 (June 1985): 225–32. http://dx.doi.org/10.1007/bf02182897.
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Çolak, Alper H., Ian D. Rotherham, and Wolfgang Spethmann. "THE IMPORTANCE OF LIGNOTUBERS IN ARID-ZONE AND HUMID-ZONE ECOSYSTEMS WITH PARTICULAR REFERENCE TO RHODODENDRON PONTICUM L." Arboricultural Journal 32, no. 2 (June 2009): 67–82. http://dx.doi.org/10.1080/03071375.2009.9747558.
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Davison, E. M., and F. C. S. Tay. "Management of tar spot disease caused by Phyllachora grevilleae subsp. grevilleae on Hakea myrtoides (Proteaceae)." Australian Journal of Botany 58, no. 5 (2010): 392. http://dx.doi.org/10.1071/bt10008.
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Hakea myrtoides Meisn. is an attractive shrub that has a restricted distribution in the south-west of Western Australia. It is not killed by fire but re-sprouts from basal lignotubers. Its leaves are often severely affected by tar spot disease, caused by the biotrophic, stromatic ascomycete Phyllachora grevilleae (Lév.) Sacc. subsp. grevilleae (Lév) Sacc. This disease is spread by ascospores that are produced during the wettest months of the year: late autumn, winter and spring. Badly infected populations of H. myrtoides were burnt, either in a controlled burn in November 2007, or in a wildfire in January 2008. The incidence of tar spot disease on leaves of burnt plants in 2008 and 2009 was 4.4%, while its incidence on unburnt plants was significantly higher (25.1%). The incidence of flowering in 2009 was similar in both burnt and unburnt populations. Tar spot disease is common on H. myrtoides; it is present on 77% of collections of this host in the Western Australian Herbarium (PERTH).
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Wasis, Reocha Aprillia, Yusanto Nugroho, and Damaris Payung. "RESPON PERTUMBUHAN BIBIT AMPUPU (Eucalyptus urophylla S.T Blake) DENGAN PEMBERIAN PUPUK NPK PADA MEDIATANAM GLEI HUMUS." Jurnal Sylva Scienteae 5, no. 5 (October 31, 2022): 776. http://dx.doi.org/10.20527/jss.v5i5.6699.
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Eucalyptus urophylla S.T Blake or ampupu is widely developed in industrial Plantation (HTI) because it is a fast-growing species and is used as raw material for pul dan paper. The advantage of this ampuu is that it is able to withstand ground surface fires because it has protection against damage to plant stems such as woody swelling of the root crown or commonly called lignotube and relatively thick skin, ampupu an grow in dry areas and is good for under growth. This study aims to analyze the growth of ampupu species to stimulate the growth of ampupu on glei humus media. Data collection in the field used the Completely Randomized Design (CRD) method. The percentage of live ampupu seedlings with the addition of NPK fertilizer had an effect on the live percentage of ampupu seedlings, a dose 5gr with a percentage of 98%, a dose of 10gr with a percentage of 82%, a dose of 15gr with a percentage of 80% and a dose of 20% with a percentage of 72%. The result of the ANOVA test on ampupu seedlings with the addition of NPK fertilizer showed significant results, which means that the treatment had a significant effect on growth in height and number of leavesEucalyptus urophylla S.T Blake atau ampupu banyak di kembangkan di Hutan Tanam Industri (HTI) karena termasuk dalam spesies cepat tumbuh dan digunakan untuk bahan baku pulp dan kertas, usaha yang dilakukan agar ampupu produktivitas tegakan meningkat melakukan pemuliaan tanaman dengan cara generatif dan vegetatif. Kelebihan ampupu ini mampu beratahan terhadap kebakaran permukaan tanah karena memiliki perlindungan terhadap kerusakan batang tanaman seperti pembengkakan berkayu dari mahkota akar atau biasa disebut lignotube dan relatif berkulit tebal, jenis ampupu dapat tumbuh di daerah kering dan baik untuk tanaman bawah. Penelitian ini bertujuan untuk menganalisis pertumbuhan jenis ampupu menguji efektifitas pupuk NPK untuk memacu pertumbuhan ampupu pada media glei humus. Pengambilan data dilapangan menggunakan metode Rancangan Acak Lengkap (RAL). Persentase hidup bibit ampupu dengan penambahan pupuk NPK memberikan pengaruh terhadap persentase hidup bibit ampupu, dosis 5gr dengan persetase hidup 98%, dosis 10gr dengan persentase 82%, dosis 15gr dengan persentase 80% dan dosis 20% dengan persentase 72%. Hasil uji Anova pada bibit ampupu dengan tambahan pupuk NPK menunjukkan hasil yang signifikan yang artinya perlakuan berpengaruh nyata terhadap pertumbuhan tinggi dan jumlah daun
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Moore, Gregory M. "The role of lignotubers (basal burls) in the stress recovery of messmate stringybark,Eucalyptus obliquaL'Herit. seedlings and its arboricultural implications." Arboricultural Journal 37, no. 2 (April 3, 2015): 113–25. http://dx.doi.org/10.1080/03071375.2015.1066559.
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Green, Ken. "Causes of stability in the alpine treeline in the Snowy Mountains of Australia - a natural experiment." Australian Journal of Botany 57, no. 3 (2009): 171. http://dx.doi.org/10.1071/bt09052.
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Large areas of treeline in the Snowy Mountains of south-eastern Australia burnt in wildfires in 2003, providing the opportunity to quantify seedling establishment at the treeline after disturbance, by comparing burnt and unburnt sites. Eucalyptus pauciflora niphophila (Maiden and Blakely) L. Johnson and Blakely, (snowgum) generally responds to fire by resprouting from lignotubers rather than by the death of the tree, hence the location of the pre-fire treeline was unaffected. Burnt and unburnt sites along the treeline therefore differed in the removal of immediate competition from understorey plants and loss of a protective canopy shelter. Five years after these fires, 27 sites were examined to determine whether the resulting conditions led to increased establishment of snowgums above the treeline. Paired plots 15 m wide were established, extending a distance of 15 m above and below the treeline in 15 unburnt and 12 burnt sites. There were significantly more seedlings in burnt than unburnt plots below the treeline. However, even in burnt areas, there were significantly fewer seedlings found above the treeline than below the treeline. Although conditions for seedling establishment at the treeline were good at burnt sites (as indicated by seedling recruitment within 15 m of the treeline), this major disturbance by fires resulted in no pulse of seedling establishment above the treeline. It is concluded that stability in the treeline of the Snowy Mountains is likely to be due to the failure of seeds to disperse uphill.
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Lewis, Tom, David Taylor, Scott Swift, and Valerie Debuse. "Factors influencing early restoration progress of a Eucalyptus tereticornis open forest on former agricultural land." Pacific Conservation Biology 18, no. 4 (2012): 263. http://dx.doi.org/10.1071/pc120263.
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We monitored an area that was revegetated with the goal of restoring a Eucalyptus tereticornis open forest on former agricultural land in central, eastern Queensland. Revegetation involved: (1) planting 60 ha of previously cleared and heavily grazed land with eight local trees species; and (2) removing cattle grazing to encourage natural regeneration in areas where some mature trees remained. We compared the revegetation site to native pasture that had also been previously cleared, with only scattered paddock trees remaining, and continued to be managed for livestock production (an area similar to the revegetation site, prior to planting) and a remnant forest (reference area). Nine years since revegetation began there was some evidence that the revegetated site was diverging from pasture in terms of understorey plant composition, sapling density and topsoil C and N. There was little divergence in terms of plant species richness (native, introduced, grass, forb and woody plant richness), herbaceous biomass and woody plant regeneration. Some monitoring plots were subject to fire (prescribed fire and or wildfire) over the period of monitoring. With increasing time since fire, the richness of native species, introduced species and grass species (both native and introduced) declined, and forb and grass species richness declined with increasing litter biomass, suggesting that the occurrence of fire and the associated removal of litter biomass has a positive influence on herbaceous diversity in this ecosystem. Woody plant regeneration persisted through lignotubers at the revegetation site and at the pasture, but this regeneration was stunted at the pasture presumably due to livestock grazing. Hence areas of former E. tereticornis forest showed promising regenerative capacity where mature trees remained and where livestock grazing was removed.
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Lacey, CJ, and RD Johnston. "Woody Clumps and Clumpwoods." Australian Journal of Botany 38, no. 3 (1990): 299. http://dx.doi.org/10.1071/bt9900299.
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Only the terms tree and shrub have been widely recognised for major growth forms of woody gymnosperms and dicotyledons, However many multi-stemmed woody plants do not conform to the definition of either category. For these plants it is here proposed that the term woody clump be used and that communities dominated by woody clumps be referred to as clumpwoods. Woody clumps are formed as a result of loss of apical dominance of a single stem and its replacement by several or many stems from tissue at or below ground level. Loss of apical dominance may be a genetically determined trait which is expressed early in the life of the plant or it may be a consequence of death, debilitation or physical damage to a mature mainstem. The stems of woody clumps may arise from morphologically unspecialised stem bases or from lignotubers, burls, rhizomes, branch and main stem layers, splitting and segmentation of shoot-root axes or root suckering. Woody clumps may remain as undivided individuals, with varying degrees of surface spread, or may divide by death or decay of connecting tissue to form clones. Large, undivided clumps could be called 'pre-clones'. Woody clumps are found in most major plant formations from the arctic to tropical regions and from deserts to swamplands. With a few notable exceptions such as North American aspens, the woody clump growth form has been ignored in ecological studies. We suggest in this paper that the recognition of a special term for this distinctive growth form would result in a clearer appreciation of its significance in natural and cultivated plant assemblages. Some of the genetic, ecological and management implications of woody clumps are discussed.
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Abreu Junior, Aureo Aparecido, and Sebastião Carlos da Silva Rosado. "CAN GENETIC VARIATIONS IN THE DEPLETION PROCESS OF STARCH STOCKS BE DRIVING CONTEMPORARY MICROEVOLUTION IN Toona ciliata VAR. australis?" CERNE 22, no. 4 (December 2016): 515–26. http://dx.doi.org/10.1590/01047760201622042201.
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ABSTRACT A simple method to establish a relationship between physiological responses of plants and thermal stresses is by quantifying the number of parenchyma cells with remaining starch stocks. The knowledge of the dynamic of starch depletion can be achieved by using statistical models such as thermal performance curves (TPC). The aim of this study was to quantify radial parenchyma cells with remaining starch stocks in order to evaluate changes in TPC regarding increases in temperature over seedlings of Toona ciliata (Australian Red cedar), in different heat induced treatments of matching both exposure time and temperature; besides of the assessment of variations in the TPC’s and also to understand whether these changes are over genetic control. We used a protocol of heat induced treatment in the stems of the seedlings, anatomical cuts and staining with neutral red for the commercial clone BV1120, which was used as template to fit polynomial curves of TPC. After these mathematical fits and validation of these models with lignotubers of Eucalyptus urophylla, we defined a depletion time of 50% (TD50) from the starch stocks for each thermal treatment, so we could compare the performance for the others five commercial clones: BV1110, BV1121, BV1151, BV1210 and BV1321. The R2 values were all above 85%. Results indicated that clone BV1110 had the highest value for remaining starch stocks at all heat induced treatments, in contrast to the clone BV1210, which had the lowest values for remaining starch stocks. The variation of the starch content indicates high values of broad-sense heritability, ranging from 97,43 to 98,48%, suggesting a possible contemporary microevolution process undergoing in Australian Red cedar. Thus, further selections can help improving the tolerance of Australian Red cedar to increasing temperatures on the environment.
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Burrows, Geoffrey E. "Gymnosperm Resprouting—A Review." Plants 10, no. 12 (November 23, 2021): 2551. http://dx.doi.org/10.3390/plants10122551.
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Gymnosperms are generally regarded as poor resprouters, especially when compared to angiosperms and particularly following major disturbance. However, is it this clear-cut? This review investigates two main aspects of gymnosperm resprouting: (i) various papers have provided exceptions to the above generalization—how frequent are these exceptions and are there any taxonomic trends?; and (ii) assuming gymnosperms are poor resprouters are there any anatomical or physiological reasons why this is the case? Five of six non-coniferous gymnosperm genera and 24 of 80 conifer genera had at least one species with a well-developed resprouting capability. This was a wider range than would be expected from the usual observation ‘gymnosperms are poor resprouters’. All conifer families had at least three resprouting genera, except the monospecific Sciadopityaceae. Apart from the aboveground stem, buds were also recorded arising from more specialised structures (e.g., lignotubers, tubers, burls and underground stems). In some larger genera it appeared that only a relatively small proportion of species were resprouters and often only when young. The poor resprouting performance of mature plants may stem from a high proportion of apparently ‘blank’ leaf axils. Axillary meristems have been recorded in a wide range of conifer species, but they often did not form an apical dome, leaf primordia or vascular connections. Buds or meristems that did form often abscised at an early stage. While this review has confirmed that conifers do not resprout to the same degree as angiosperms, it was found that a wide diversity of gymnosperm genera can recover vegetatively after substantial disturbance. Further structural studies are needed, especially of: (i) apparently blank leaf axils and the initial development of axillary meristems; (ii) specialised regeneration structures; and (iii) why high variability can occur in the resprouting capacity within species of a single genus and within genera of the same family.