490 resultados para Acacia Woodlands


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The impact of excessive sediment loads entering into the Great Barrier Reef lagoon has led to increased awareness of land condition in grazing lands. Improved ground cover and land condition have been identified as two important factors in reducing sediment loads. This paper reports the economics of land regeneration using case studies for two different land types in the Fitzroy Basin. The results suggest that for sediment reduction to be achieved from land regeneration of more fertile land types (brigalow blackbutt) the most efficient method of allocating funds would be through extension and education. However for less productive country (narrow leaved ironbark woodlands) incentives will be required. The analysis also highlights the need for further scientific data to undertake similar financial assessments of land regeneration for other locations in Queensland.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The aim of this project was to investigate the suitability of thinnings from a range of plantation species for use as vineyard posts. The hardwood plantation species examined were Eucalyptus grandis, E. globulus, E. pilularis, E. dunnii, E. cladocalyx and Corymbia maculata, while Acacia mearnsii was obtained from natural regrowth. The softwood plantation species were P. elliottii, P. radiata and Araucaria cunninghamii. Variables examined included: three air drying regimes; microwave conditioning of E. grandis and E. globulus; two preservative treatments for hardwoods (alkaline copper quaternary compound (ACQ) and pigment emulsified creosote (PEC)); and two preservative treatments for softwood species (ACQ and, for Pinus radiata copper chromium arsenic (CCA)). A further aim was to install treated posts in commercial vineyards for demonstration purposes. From an earlier trial of three hardwood species treated with PEC, demonstration posts previously installed were also to be inspected annually for three years, and any movement of polycyclic aromatic hydrocarbons (PAH) from the posts monitored.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This guide applies to spotted gum - ironbark forests and woodlands. Topics covered in the guide include: *The spotted gum - ironbark ecosystem; *General effects of burning practices; *Understandinng the effects of fire management; *Timber production; *Livestock grazing production; *Balancing production and biodiversity; *Fire management planning for the property; *Recommendtaions for landholders. These guidelines have been prepared for spotted gum - ironbark forests and woodlands and are not necessarily applicable to other forest and woodland ecosystems. The recommendations provided in these guidelines should be used as a guide only.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Leaf-litter thrips were much more common and diverse in dry sclerophyll forest than in wetter forest types in subtropical southeast Queensland, Australia. In dry sclerophyll forest, the species composition of thrips in leaf-litter was strongly differentiated from the thrips fauna associated with bark of the trees Eucalyptus major and Acacia melanoxylon (4 of 34 species in common). The species composition of bark-dwelling thrips was similar across the two tree species and also across two eucalypts with different bark types, Eucalyptus major (flaky) and Eucalyptus siderophloia (rough). The diversity of thrips from the leaf-litter was not differentiated across all of these tree species. Virtually all thrips collected were Phlaeothripidae, subfamilies Idolothripinae and Phlaeothripinae. Idolothripinae were associated almost exclusively with leaf-litter, but Phlaeothripinae were in leaf-litter and bark. The association of fungal-feeding thrips with dry sclerophyll forest raises questions about their ecological requirements and the role they play in nutrient cycling. © 2012 Copyright Taylor and Francis Group, LLC.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Remote detection of management-related trend in the presence of inter-annual climatic variability in the rangelands is difficult. Minimally disturbed reference areas provide a useful guide, but suitable benchmarks are usually difficult to identify. We describe a method that uses a unique conceptual framework to identify reference areas from multitemporal sequences of ground cover derived from Landsat TM and ETM+ imagery. The method does not require ground-based reference sites nor GIS layers about management. We calculate a minimum ground cover image across all years to identify locations of most persistent ground cover in years of lowest rainfall. We then use a moving window approach to calculate the difference between the window's central pixel and its surrounding reference pixels. This difference estimates ground-cover change between successive below-average rainfall years, which provides a seasonally interpreted measure of management effects. We examine the approach's sensitivity to window size and to cover-index percentiles used to define persistence. The method successfully detected management-related change in ground cover in Queensland tropical savanna woodlands in two case studies: (1) a grazing trial where heavy stocking resulted in substantial decline in ground cover in small paddocks, and (2) commercial paddocks where wet-season spelling (destocking) resulted in increased ground cover. At a larger scale, there was broad agreement between our analysis of ground-cover change and ground-based land condition change for commercial beef properties with different a priori ratings of initial condition, but there was also some disagreement where changing condition reflected pasture composition rather than ground cover. We conclude that the method is suitably robust to analyse grazing effects on ground cover across the 1.3 x 10(6) km(2) of Queensland's rangelands. Crown Copyright (c) 2012 Published by Elsevier Inc. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Microbes and their exopolysaccharides (EPS) can block xylem vessels, thereby increasing the hydraulic resistance and decreasing the vase life of cut flowers and foliage. Scanning electron microscopy (SEM) provides a powerful tool for investigation of bacteria-induced xylem occlusion. However, conventional preparation protocols for SEM involving chemicals can cause loss of hydrated EPS material, and thereby damage the bacterial biofilms during dehydration. A modified chemical fixation protocol involving pre-fixation with 75 mM lysine plus 2.5% glutaraldehyde followed by the normal fixation in 3% glutaraldehyde was, therefore, tested for improved preservation of bacterial biofilm at the stem-ends of cut Acacia holosericea foliage stems. Stem-end segments with different stages of bacterial growth were obtained from stems stood into water. The lysine-based protocol was compared with four other processing protocols of critical point drying (CPD) without fixation (control), freeze-drying (FD), conventional chemical fixation followed by drying with hexamethyldisilazane (HMDS), and conventional chemical fixation with CPD. The non-fixed control. FD and the glutaraldehyde fixation with HMDS drying gave poor preservation of hydrated material, including bacterial EPS. Conventional glutaraldehyde fixation followed by CPD was superior to these three methods in terms of better preserving the EPS. However, this fourth method gave condensation of biofilms during dehydration. In contrast, the modified lysine-based protocol resulted in superior preservation of EPS and biofilm structure. Thus, this fifth method was the most appropriate for examination of bacterial stem-end blockage in cut ornamentals. (C) 2012 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: In order to rapidly and efficiently screen potential biofuel feedstock candidates for quintessential traits, robust high-throughput analytical techniques must be developed and honed. The traditional methods of measuring lignin syringyl/guaiacyl (S/G) ratio can be laborious, involve hazardous reagents, and/or be destructive. Vibrational spectroscopy can furnish high-throughput instrumentation without the limitations of the traditional techniques. Spectral data from mid-infrared, near-infrared, and Raman spectroscopies was combined with S/G ratios, obtained using pyrolysis molecular beam mass spectrometry, from 245 different eucalypt and Acacia trees across 17 species. Iterations of spectral processing allowed the assembly of robust predictive models using partial least squares (PLS). RESULTS: The PLS models were rigorously evaluated using three different randomly generated calibration and validation sets for each spectral processing approach. Root mean standard errors of prediction for validation sets were lowest for models comprised of Raman (0.13 to 0.16) and mid-infrared (0.13 to 0.15) spectral data, while near-infrared spectroscopy led to more erroneous predictions (0.18 to 0.21). Correlation coefficients (r) for the validation sets followed a similar pattern: Raman (0.89 to 0.91), mid-infrared (0.87 to 0.91), and near-infrared (0.79 to 0.82). These statistics signify that Raman and mid-infrared spectroscopy led to the most accurate predictions of S/G ratio in a diverse consortium of feedstocks. CONCLUSION: Eucalypts present an attractive option for biofuel and biochemical production. Given the assortment of over 900 different species of Eucalyptus and Corymbia, in addition to various species of Acacia, it is necessary to isolate those possessing ideal biofuel traits. This research has demonstrated the validity of vibrational spectroscopy to efficiently partition different potential biofuel feedstocks according to lignin S/G ratio, significantly reducing experiment and analysis time and expense while providing non-destructive, accurate, global, predictive models encompassing a diverse array of feedstocks.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Endoraecium (Raveneliaceae, Pucciniales) is a genus of rust that infects several species of Acacia (Fabaceae) in Australia, south-east Asia and Hawaii. Thirteen species of Endoraecium have been described, including seven species that are endemic to Australia, one species to south-east Asia and five to Hawaii. This study investigated the systematics of Endoraecium from 50 specimens in Australia and south-east Asia with a combined morphological and molecular approach. Phylogenetic analyses were conducted on combined datasets of the SSU, ITS and LSU regions of rDNA. The recovered phylogeny (i) supported a recent division of Endoraecium digitatum into five separate species based on morphology and host specificity and (ii) found lineages that did not correspond with known species.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The gall rusts on Acacia spp. and Paraserianthes falcataria are caused by species of Uromycladium. Morphology and a phylogenetic analysis of four loci from ribosomal (SSU, ITS, LSU) and mitochondrial (CO3) DNA, showed that the rust on P. falcataria differed from U. tepperianum. Uromycladium falcatarium sp. nov. is described to accommodate this taxon, which can be differentiated from other species of Uromycladium by teliospore wall morphology, host genus and DNA sequence data.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Novel species of fungi described in the present study include the following from South Africa: Alanphillipsia aloeicola from Aloe sp., Arxiella dolichandrae from Dolichandra unguiscati, Ganoderma austroafricanum from Jacaranda mimosifolia, Phacidiella podocarpi and Phaeosphaeria podocarpi from Podocarpus latifolius, Phyllosticta mimusopisicola from Mimusops zeyheri and Sphaerulina pelargonii from Pelargonium sp. Furthermore, Barssia maroccana is described from Cedrus atlantica (Morocco), Codinaea pini from Pinus patula (Uganda), Crucellisporiopsis marquesiae from Marquesia acuminata (Zambia), Dinemasporium ipomoeae from Ipomoea pes-caprae (Vietnam), Diaporthe phragmitis from Phragmites australis (China), Marasmius vladimirii from leaf litter (India), Melanconium hedericola from Hedera helix (Spain), Pluteus albotomentosus and Pluteus extremiorientalis from a mixed forest (Russia), Rachicladosporium eucalypti from Eucalyptus globulus (Ethiopia), Sistotrema epiphyllum from dead leaves of Fagus sylvatica in a forest (The Netherlands), Stagonospora chrysopyla from Scirpus microcarpus (USA) and Trichomerium dioscoreae from Dioscorea sp. (Japan). Novel species from Australia include: Corynespora endiandrae from Endiandra introrsa, Gonatophragmium triuniae from Triunia youngiana, Penicillium coccotrypicola from Archontophoenix cunninghamiana and Phytophthora moyootj from soil. Novelties from Iran include Neocamarosporium chichastianum from soil and Seimatosporium pistaciae from Pistacia vera, Xenosonderhenia eucalypti and Zasmidium eucalyptigenum are newly described from Eucalyptus urophylla in Indonesia. Diaporthe acaciarum and Roussoella acacia are newly described from Acacia tortilis in Tanzania. New species from Italy include Comoclathris spartii from Spartium junceum and Phoma tamaricicola from Tamarix gallica. Novel genera include (Ascomycetes): Acremoniopsis from forest soil and Collarina from water sediments (Spain), Phellinocrescentia from a Phellinus sp. (French Guiana), Neobambusicola from Strelitzia nicolai (South Africa), Neocladophialophora from Quercus robur (Germany), Neophysalospora from Cotymbia henryi (Mozambique) and Xenophaeosphaeria from Grewia sp. (Tanzania). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Novel species of fungi described in the present study include the following from South Africa: Alanphillipsia aloeicola from Aloe sp., Arxiella dolichandrae from Dolichandra unguiscati, Ganoderma austroafricanum from Jacaranda mimosifolia, Phacidiella podocarpi and Phaeosphaeria podocarpi from Podocarpus latifolius, Phyllosticta mimusopisicola from Mimusops zeyheri and Sphaerulina pelargonii from Pelargonium sp. Furthermore, Barssia maroccana is described from Cedrus atlantica (Morocco), Codinaea pini from Pinus patula (Uganda), Crucellisporiopsis marquesiae from Marquesia acuminata (Zambia), Dinemasporium ipomoeae from Ipomoea pes-caprae (Vietnam), Diaporthe phragmitis from Phragmites australis (China), Marasmius vladimirii from leaf litter (India), Melanconium hedericola from Hedera helix (Spain), Pluteus albotomentosus and Pluteus extremiorientalis from a mixed forest (Russia), Rachicladosporium eucalypti from Eucalyptus globulus (Ethiopia), Sistotrema epiphyllum from dead leaves of Fagus sylvatica in a forest (The Netherlands), Stagonospora chrysopyla from Scirpus microcarpus (USA) and Trichomerium dioscoreae from Dioscorea sp. (Japan). Novel species from Australia include: Corynespora endiandrae from Endiandra introrsa, Gonatophragmium triuniae from Triunia youngiana, Penicillium coccotrypicola from Archontophoenix cunninghamiana and Phytophthora moyootj from soil. Novelties from Iran include Neocamarosporium chichastianum from soil and Seimatosporium pistaciae from Pistacia vera, Xenosonderhenia eucalypti and Zasmidium eucalyptigenum are newly described from Eucalyptus urophylla in Indonesia. Diaporthe acaciarum and Roussoella acacia are newly described from Acacia tortilis in Tanzania. New species from Italy include Comoclathris spartii from Spartium junceum and Phoma tamaricicola from Tamarix gallica. Novel genera include (Ascomycetes): Acremoniopsis from forest soil and Collarina from water sediments (Spain), Phellinocrescentia from a Phellinus sp. (French Guiana), Neobambusicola from Strelitzia nicolai (South Africa), Neocladophialophora from Quercus robur (Germany), Neophysalospora from Cotymbia henryi (Mozambique) and Xenophaeosphaeria from Grewia sp. (Tanzania). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Native Mediterranean forests in Australia are dominated by two tree genera, Eucalyptus and Acacia, while Pinus and Eucalyptus dominate plantation forestry. In native forests, there is a high diversity of phloem and wood borers across several families in the Coleoptera and Lepidoptera. In the Coleoptera, cerambycid beetles (Cerambycidae), jewel beetles (Buprestidae), bark, ambrosia and pinhole beetles (Curculionidae) and pinworms (Lymexelidae) are some of the most commonly found beetles attacking eucalypts and acacias. In the Lepidoptera, wood moths (Cossidae), ghost moths (Hepialidae) and borers in the Xyloryctidae (subfamily Xyloryctinae) are most common. In contrast to native forests, there is a much more limited range of native insects present in Australian plantations, particularly in exotic Pinus spp. plantations, although eucalypt plantations do share some borers in common with native forests. This chapter reviews the importance of these borers in Australian forests primarily from an economic perspective (i.e. those species that cause damage to commercial tree species) and highlights a paucity of native forest species that commonly kill trees relative to the large scales regularly seen in North America and Europe.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Chinee apple (Ziziphus mauritiana Lam.) is a thorny tree that is invading tropical woodlands of northern Australia. The present study reports three experiments related to the seed dynamics of chinee apple. Experiment 1 and 2 investigated persistence of seed lots under different soil types (clay and river loam), levels of pasture cover (present or absent) and burial depths (0, 2.5, 10 and 20 cm). Experiment 3 determined the germination response of chinee apple seeds to a range of alternating day/night temperatures (11/6°C up to 52/40°C). In the longevity experiments (Expts 1 and 2), burial depth, soil type and burial duration significantly affected viability. Burial depth had the greatest influence, with surface located seeds generally persisting for longer than those buried below ground. Even so, no viable seeds remained after 18 and 24 months in the first and second experiment, respectively. In Expt 3 seeds of chinee apple germinated under a wide range of alternating day/night temperatures ranging from 16/12°C to 47 /36°C. Optimal germination (77%) occurred at 33/27°C and no seeds germinated at either of the lowest (11/6°C) or highest (52/40°C) temperature regimes tested. These findings indicated that chinee apple has the potential to expand its current distribution to cooler areas of Australia. Control practices need to be undertaken for at least two years to exhaust the seed bank.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The impacts of fragmentation and recreational use on the hemiboreal urban forest understorey vegetation and the microbial community of the humus layer (the phospholipid fatty acid (PLFA) pattern, microbial biomass and microbial activity, measured as basal respiration) were examined in the greater Helsinki area, southern Finland. Trampling tolerance of 1) herb-rich OMT, 2) mesic MT, and 3) sub-xeric VT forests (in decreasing order of fertility) was studied by comparing relative understorey vegetation cover (urban/untrampled reference ratio) of the three forest types. The trampling tolerance of forest vegetation increased with the productivity of the site (sub-xeric < mesic < herb-rich). Wear of understorey vegetation correlated positively with the number of residents (i.e., recreational pressure) around the forest patch. An increase of 15000 residents within a radius of 1 km around a forest patch was associated with ca. 30% decrease in the relative understorey vegetation cover. The cover of dwarf shrub Vaccinium myrtillus in particular decreased with increasing levels of wear. The cover of mosses in urban forests was less than half of that in untrampled reference areas. Cover of tree saplings, mainly Sorbus aucuparia, and some resilient herbs was higher than in the reference areas. In small urban forest fragments, broad-leaved trees, grasses and herbs were more abundant and mosses were scarcer than in larger urban forest areas. Thus, due to trampling and edge effects, resilient herb and grass species are replacing sensitive dwarf shrubs, mosses and lichens in urban forests. Differences in the soil microbial community structure were found between paths and untrampled areas and the effects of paths extended more than one meter from the paths. Paths supported approximately 25-30% higher microbial biomass with a transition zone of at least 1 m from the path edge. However, microbial activity per unit of biomass was lower on paths than in untrampled areas. Furthermore, microbial biomass and activity were 30-45% lower at the first 20 m into the forest fragments, due to low moisture content of humus near the edge. The decreased microbial activity detected at forest edges and paths implies decreased litter decomposition rates, and thus, a change in nutrient cycling. Changes in the decomposition and nutrient supply may in turn affect the diversity and function of plant communities in urban forests. Keywords: boreal forest vegetation, edge effects, phospholipid fatty acids, trampling, urban woodlands, wear

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Regeneration ecology, diversity of native woody species and its potential for landscape restoration was studied in the remnant natural forest at the College of Forestry and Natural Resources at Wondo Genet, Ethiopia. The type of forest is Afromontane rainforest , with many valuable tree species like Aningeria adolfi-friederici, and it is an important provider of ecological, social and economical services for the population that lives in this area. The study contains two parts, natural regeneration studies (at the natural forest) and interviews with farmers in the nearby village of the remnant patch. The objective of the first part was to investigate the floristic composition, densitiy and regeneration profiles of native woody species in the forest, paying special attention to woody species that are considered the most relevant (socio-economic). The second part provided information on woody species preferred by the farmers and on multiple uses of the adjacent natural forest, it also provided information and analysed perceptions on forest degradation. Systematic plot sampling was used in the forest inventory. Twenty square plots of 20 x 20 m were assessed, with 38 identified woody species (the total number of species was 45), representing 26 families. Of these species 61% were trees, 13% shrubs, 11% lianas and 16% species that could have both life forms. An analysis of natural regeneration of five important tree species in the natural forest showed that Aningeria adolfi-friederici had the best regeneration results. An analysis of population structure (as determined by height classes) of two commercially important woody species in the forest, Aningeria adolfi-friederici and Podocarpus falcatus, showed a marked difference: Aningeria had a typical “reversed J” frequency distribution, while Podocarpus showed very low values in all height classes. Multi dimensional scaling (MDS) was used to map the sample plots according to their similarity in species composition, using the Sørensen quantitative index, coupled with indicator species analysis .Three groups were identified with respective indicator species: Group 1 – Adhatoda schimperiana, Group 2 – Olea hochstetteri , Group 3 – Acacia senegal and Aningeria adolfi-friederici. Thirty questionnaire interviews were conducted with farmers in the village of Gotu Onoma that use the nearby remant forest patch. Their tree preferences were exotic species such as Eucalyptus globulus for construction and fuelwood and Grevillea robusta for shade and fertility. Considering forest land degradation farmers were aware of the problem and suggested that the governmental institutions address the problem by planting more Eucalyptus globulus. The natural forest seemed to have moderate levels of disturbance and it was still floristically diverse. However, the low rate of natural regeneration of Podocarpus falcatus suggested that this species is threatened and must be a priority in conservation actions. Plantations and agroforestry seem to be possible solutions for rehabilitation of the surrounding degraded lands, thereby decreasing the existent pressure in the remnant natural forest.