Anatomical Aspects of Water Movement Through Stems of Mountain Ash (Eucalyptus regnans F. Muell.)

1985 ◽  
Vol 33 (3) ◽  
pp. 287 ◽  
Author(s):  
NJ Legge
Keyword(s):  
Surface Area ◽  
Microscopic Examination ◽  
Water Movement ◽  
Lateral Roots ◽  
Age Classes ◽  
Young Tree ◽  
Eucalyptus Regnans ◽  
Mountain Ash ◽  
Limited Degree ◽  
Old Trees

Introduction of a stain through the severed roots of Eucalyptus regnans of two age classes showed that a spiral interlocked sap ascent pattern in young trees tended towards a vertical sectorial pattern by age 40 years. Microscopic examination of the stained wood suggests that intercellular water movement occurs principally via the pits. Serial transverse sections of wood from a young tree showed a limited degree of intervessel contact, with a network coefficient of 13.7 contacts m-1 and approx. 0.9% of vessel surface area in contact with other vessels. Analysis of the frequency of vessel endings indicates an average vessel length of approx. 1.8 m. Trunk segments of 40-year-old trees had relative conductivities of approx. 3.3 x 10-11 m2, while small lateral roots had values up to 10 times greater.

The influence of time since fire and distance from fire boundary on the distribution and abundance of arboreal marsupials in Eucalyptus regnans-dominated forest in the Central Highlands of Victoria

2002 ◽  
Vol 29 (2) ◽  
pp. 151 ◽  
Author(s):  
R. van der Ree ◽  
R. H. Loyn
Keyword(s):  
Brushtail Possum ◽  
Age Classes ◽  
Eucalyptus Regnans ◽  
Salvage Logging ◽  
Age Class ◽  
Time Since Fire ◽  
Arboreal Marsupials ◽  
Mountain Ash ◽  
Central Highlands ◽  
The Impact

The impact of time since fire after two consecutive wildfires 44 years apart (1939 and 1983) within the same area, and the distance from the fire boundary (<100 m or 500-2000 m), were investigated in relation to the distribution and abundance of arboreal marsupials in 1994. Arboreal marsupials were censused by stagwatching and spotlighting in two relatively young age classes of mountain ash (Eucalyptus regnans) dominated forest in the Central Highlands of Victoria. Five species of arboreal marsupial were detected, but only three were detected in sufficient numbers to determine habitat preferences. Petauroides volans (greater glider) was statistically more abundant in 1939 regrowth forests, while Trichosurus caninus (mountain brushtail possum) showed no significant preference for either age class of forest. All but one record of Gymnobelideus leadbeateri (Leadbeater's possum) came from young forest, though the effect of age-class was not statistically significant. Distance from fire boundary explained little or no variation in mammal distribution or abundance. While the actual number of hollow-bearing trees was similar in both age classes of forest, the long-term lifespan of hollow-bearing trees in more recently burnt forest is predicted to be lower than in unburnt or not recently burnt forest. Post-fire salvage logging following the 1983 wildfires appears to have reduced the number of hollow-bearing trees at sites burnt in 1983.

scholarly journals Its What’s on the Inside That Counts: An Effective, Efficient, and Streamlined Method for Quantification of Octocoral Symbiodiniaceae and Chlorophyll

2021 ◽  
Vol 8 ◽  
Author(s):  
Rosemary Kate Steinberg ◽  
Emma L. Johnston ◽  
Teresa Bednarek ◽  
Katherine A. Dafforn ◽  
Tracy D. Ainsworth
Keyword(s):  
Protein Content ◽  
Surface Area ◽  
Water Movement ◽  
Chlorophyll Concentration ◽  
Dry Weight ◽  
Accurate Method ◽  
Host Protein ◽  
Biomass Composition ◽  
Wet Weight ◽  
Chlorophyll Concentrations

Ocean warming driven bleaching is one of the greatest threats to zooxanthellate cnidarians in the Anthropocene. Bleaching is the loss of Symbiodiniaceae, chlorophyll, or both from zooxanthellate animals. To quantify bleaching and recovery, standardised methods for quantification of Symbiodiniaceae and chlorophyll concentrations have been developed for reef-building scleractinian corals, but no such standard method has been developed for octocorals. For stony corals, quantification of Symbiodiniaceae and chlorophyll concentrations often relies on normalisation to skeletal surface area or unit of biomass [i.e., protein, ash-free dry weight (AFDW)]. Stiff octocorals do not change their volume, as such studies have used volume and surface area to standardise densities, but soft-bodied octocorals can alter their size using water movement within the animal; therefore, Symbiodiniaceae and chlorophyll cannot accurately be measured per unit of surface area and are instead measured in units of Symbiodiniaceae and chlorophyll per μg of host protein or AFDW. Though AFDW is more representative of the full biomass composition than host protein, AFDW is more time and resource intensive. Here, we provide a streamlined methodology to quantify Symbiodiniaceae density, chlorophyll concentration, and protein content in soft-bodied octocorals. This technique uses minimal equipment, does not require freeze-drying or burning samples to obtain ash weight, and is effective for down to 0.2 g wet tissue. Bulk samples can be centrifuged, the Symbiodiniaceae pellet washed, and the supernatant saved for protein analysis. This efficient technique allows for clean, easy to count samples of Symbiodiniaceae with minimal animal protein contamination. Chlorophyll a and c2 extractions occurs at different rates, with chlorophyll a taking 24 h to extract completely at 4°C and chlorophyll c2 taking 48 h. Finally, we found that where necessary, wet weight may be used as a proxy for protein content, but the correlation of protein and wet weight varies by species and protein should be used when possible. Overall, we have created a rapid and accurate method for quantification of bleaching markers in octocorals.

Does nitrogen limit the growth of native eucalypt forests:some observations for mountain ash (Eucalyptus regnans)

2001 ◽  
Vol 52 (1) ◽  
pp. 111 ◽  
Author(s):  
P. M. Attiwill ◽  
P. M. Attiwill ◽  
B. M. May ◽  
B. M. May
Keyword(s):  
N Availability ◽  
Ecological Research ◽  
Biological Fixation ◽  
Ecological Processes ◽  
Eucalyptus Regnans ◽  
Rate Of Growth ◽  
Wild Fire ◽  
N Supply ◽  
Eastern Australia ◽  
Mountain Ash

It is often stated that the availability of N limits the rate of growth of native forests. We discuss this hypothesis with particular reference to the mountain ash (Eucalyptus regnans) forests of south-eastern Australia. The abundance of 15 N in leaves and soil of mountain ash forest is in accord with data for Northern Hemisphere temperate forests and for tropical forests,and indicates that N availability is relatively high.None of the nutrient elements has limited the rate of growth of mountain ash forest regenerating after major disturbance (clear-felling and intense wild-fire). There is some evidence that P may be limiting to some ecological processes (e.g. the rate of litter decomposition). We conclude that phosphorus is more likely to be limiting than nitrogen in mountain ash forest because nitrogen cycling is conservative and continual inputs of N through biological fixation supplement this conservative N supply, and the stands never become N-deficient. The development of methodologies to determine the rate of N2-fixation in forests should be of high priority in ecological research.

Economics of a nest-box program for the conservation of an endangered species: a reappraisal

2001 ◽  
Vol 31 (11) ◽  
pp. 1992-2003 ◽  
Author(s):  
Daniel A Spring ◽  
Michael Bevers ◽  
John OS Kennedy ◽  
Dan Harley
Keyword(s):  
Net Present Value ◽  
Population Recovery ◽  
Optimal Management ◽  
Present Value ◽  
Eucalyptus Regnans ◽  
Nest Boxes ◽  
Mountain Ash ◽  
Local Abundance ◽  
Leadbeater's Possum

An optimization model is developed to identify timing and placement strategies for the installation of nest boxes and the harvesting of timber to meet joint timber–wildlife objectives. Optimal management regimes are determined on the basis of their impacts on the local abundance of a threatened species and net present value (NPV) and are identified for a range of NPV levels to identify production possibility frontiers for abundance and NPV. We apply the model to a case study focusing on an area of commercially productive mountain ash (Eucalyptus regnans F. Muell.) forest in the Central Highlands region of Victoria, Australia. The species to be conserved is Leadbeater's possum (Gymnobelideus leadbeateri McCoy), which is locally limited by a scarcity of nesting hollows. The modeling is exploratory but indicates that nest boxes may offer a promising population recovery tool if consideration is taken of their placement and areal extent through time.

Mountain Ash

2015 ◽  
Author(s):  
David Lindenmayer ◽  
David Blair ◽  
Lachlan McBurney ◽  
Sam Banks
Keyword(s):  
Forest Ecosystems ◽  
Fire Severity ◽  
Fire Dynamics ◽  
High Severity ◽  
Fire Environment ◽  
Arboreal Marsupials ◽  
New Findings ◽  
Mountain Ash ◽  
Old Trees ◽  
Very High

Mountain Ash draws together exciting new findings on the effects of fire and on post-fire ecological dynamics following the 2009 wildfires in the Mountain Ash forests of the Central Highlands of Victoria. The book integrates data on forests, carbon, fire dynamics and other factors, building on 6 years of high-quality, multi-faceted research coupled with 25 years of pre-fire insights. Topics include: the unexpected effects of fires of varying severity on populations of large old trees and their implications for the dynamics of forest ecosystems; relationships between forest structure, condition and age and their impacts on fire severity; relationships between logging and fire severity; the unexpectedly low level of carbon stock losses from burned forests, including those burned at very high severity; impacts of fire at the site and landscape levels on arboreal marsupials; persistence of small mammals and birds on burned sites, including areas subject to high-severity fire, and its implications for understanding how species in this group exhibit post-fire recovery patterns. With spectacular images of the post-fire environment, Mountain Ash will be an important reference for scientists and students with interests in biodiversity, forests and fire.

Studies on the Mycorrhizae of Eucalyptus regnans F.muell

1976 ◽  
Vol 24 (6) ◽  
pp. 723 ◽  
Author(s):  
DH Ashton
Keyword(s):  
Lateral Roots ◽  
Mycorrhizal Fungus ◽  
Root Hairs ◽  
High Light Intensity ◽  
Eucalyptus Regnans ◽  
Carbon 14 ◽  
Nitrogenous Fertilizer ◽  
External Mycelium ◽  
Mycorrhizal Development ◽  
Growth Of Seedlings

Eucalyptus regnans mycorrhizae vary from simple to coralloid forms, and their surfaces are commonly smooth or conspicuously enmeshed with external mycelium. At least 18 different basidiomycetes may be intimately associated with dense weft-type mycorrhizae; six agarics have been induced to form simple or diffuse mycorrhizae under sterile conditions. Individual mycorrhizae vary in form and colour with both age and the nature of the symbiont. In the field, mycorrhizae are longer-lived than uninfected lateral roots. The earliest stages of infection of new roots appear to occur via root hairs, and intracellular hyphae are produced. This is rapidly followed by the development of either ectendotrophic, ectotrophic or superficial mycorrhizae. Mycorrhizal development is enhanced by high light intensity, diminished by high levels of nitrogenous fertilizer, but apparently unaffected by high levels of phosphate. Experiments suggest that a transfer of carbon-14 takes place from the leaves to the mycorrhizal mantle. Inoculation of E. regnans by Mesophellia arenaria in relatively rich loams of south Gippsland improved the growth of E. regnans seedlings in both field and the glasshouse. The sterilization by gamma-rays of krasnozem topsoil from the forest improved the growth of E. regnans seedlings. Growth of seedlings was further enhanced by the inoculation of such soil with a mycorrhizal fungus (probably inocybe olivaceofulvus).

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