The relationships were examined between measurements of forest habitat (10 explanatory variables: X) and densities of three species of arboreal marsupials (greater glider, feathertail glider and sugar glider); the sum of these three and an additional five species that occurred; species richness and diversity of all eight species present in the area (six response variables: Y). The habitat variables were: landform profile; elapsed time since a severe fire; degree of forest maturity (total basal area of wood); an index of den tree density; ratio of number of regeneration size trees to den trees; floristic diversity; basal area of peppermints; basal area of gums; basal area of eucalypts with a low level of nutrients in their foliage; and an index of potassium concentration in the foliage. The principal component transformation of the X set of variables (PCA) was used as an aid to interpret the individual response of Y to joint intercorrelated explanatory variables X. The regressions of Y on PCA-transformed X explained 76.2% of variation in density for the greater glider, 50.4% for the feathertail glider, 21.1% for the sugar glider, 68.3% for all arboreal marsupials, 49.7% for species richness and 30.1% for species diversity. The weak regressions obtained for densities for the sugar glider were attributed to probable non-measurement of important understorey habitat variables for this species, and those for species richness and diversity, to the presence of a curvilinear rather than linear relationship to foliage nutrients. The gradient in foliage nutrient concentration appears to be the major determinant of the density and species richness and diversity of arboreal marsupials in the Eden forests. Exceptions to the trend seem to occur where the forests include certain xeromorphic eucalypt species that are high in foliage nutrients yet poor in fauna, and, for the feathertail and sugar glider, in those sections of the Eden forests exhibiting fire successional stages and that are usually composed of eucalypts with low nutrient levels in their foliage.

No abstract

Dothistroma needle blight is a serious foliar disease in Australian Pinus radiata plantations causing defoliation, decreased productivity and, in extreme cases, tree death. Conventional methods of monitoring forest health such as aerial survey and ground assessments are labor intensive, time consuming, and subjective. Remote sensing provides a synoptic view of the canopy and can indicate areas affected by damaging agents such as pests and pathogens. Hyperspectral airborne remote sensing imagery (CASI-2) was acquired over pine stands in southern New South Wales, Australia which had been ground assessed and ranked on an individual tree basis, according to the extent of Dothistroma needle blight. A series of spectral indices were tested using two different approaches for extracting crown-scale reflectance measurements and relating these to ground-based estimates of severity. Dothistroma needle blight is most severe in the lower crown and statistically significant relationships were found between crown reflectance values and ground estimates using a 'halo' approach (which ignored each tree crown's brightest central pixels). Independent accuracy assessment of the method indicated that the technique could successfully detect three levels of Dothistroma needle blight infection with an accuracy of over 70%.

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The intensity of use of forested country in the Kakadu National Park area b\ feral Asiatic water buffalo can be largely predicted from the area of river floodplain in the vicinity of the site, and tree canopy cover on the site. Thus some areas of monsoon forest appear to have sustained intensive use by buffalo for over a century whereas other areas have probably been little used.With sites exhibiting little buffalo use, mean DBH of trees increased with foliage height diversity (FHD). However, the sites more intensively used by buffalo had a lower canopy and did not exhibit any increase in mean DBH with a pronounced increase in FHD. Other vegetational relationships displayed by the two groups of sites are discussed. Comparison of the monsoon forest sites suggests that compaction of soil by buffalo has caused the death of large trees due to poor recharge of groundwater.The two groups of monsoon forest sites exhibited a wide variety of faunal relationships with FHD. Some species appear to be favoured while others are disadvantaged to various degrees by the habitat changes caused by the buffalo. The most intensively used site appears to have exceeded a threshold in that a number of faunal trends were reversed on that site.The impact of buffalo on some monsoon forest sites is much more fundamental than anticipated. But other sites which appear to be naturally protected by their location have experienced much less change due to buffalo. * Deceased.