7 resultados para Estimação robusta
em eResearch Archive - Queensland Department of Agriculture
Resumo:
A highly polymorphic genetic locus of Stout Whiting was examined for evidence of geographical subdivision amongst samples collected from three locales in southern Queensland waters. Statistical indicators of subdivision were not significantly different from zero, suggesting that it is unlikely that the Stout Whiting resource in southern Queensland is genetically subdivided into separate stocks. It is recommended that the full-scale genetic program not proceed and that the resource be managed as a single stock.
Resumo:
This study presents results from an experimental 10-day research charter that was designed to quantify the effects of a) a turtle excluder device (TED) and b) a radial escape section bycatch reduction device (BRD) and c) both devices together, on prawn and bycatch catch rates in the Queensland shallow water eastern king prawn (Penaeus plebejus) trawl fishery. The bycatch was comprised of 250 taxa, mainly gurnards, whiting, lizard fish, flathead, dragonets, portunid crabs, turretfish and flounders. The observed mean catch rates of bycatch and marketable eastern king prawns from the standard trawl net (i.e., net with no TED or BRD) used during the charter were 11.06 (se 0.90) kg per hectare swept by the trawl gear (ha-1) and 0.94 kg ha-1, respectively. For the range of depths sampled (20.1-90.7 m), bycatch catch rates declined significantly at a rate of 0.14 kg ha-1 for every 1 m increase in depth, while prawn catch rates were unaffected. When both the TED and radial escape section BRD were used together they resulted in a 24% reduction in total bycatch catch rate compared to a standard net, but at a 20% reduction in marketable prawn catch rate. The largest reductions were achieved for stout whiting Sillago robusta (57% reduction) and yellowtail scad Trachurus novaezelandiae (32% reduction). Multidimensional scaling and analysis of similarities revealed that bycatch assemblages differed significantly between depths and latitude, but not between the different combinations of bycatch reduction devices. Despite the lowered prawn catch rates, the reduced bycatch catch rates are promising, particularly for S. robusta which is not permitted to be retained by the prawn trawl fleet and yet experiences considerable incidental fishing mortality, and because it is targeted in a separate licensed commercial fishery.
Resumo:
Seven hardwood species were tested as underplants under Pinus elliottii plantations on the coastal lowlands of south-east Queensland. The species tested were: Flindersia brayleyana (F. Muell) (Queensland maple), F. australis (R. Br.), (crow's ash), Swietenia macrophylla (King) (American mahogany), Grevillea robusta (A. cunn) (southern silky oak), Elaeocarpus grandis (F. Muell) (silver quandong), F. ifflaiana (F. Meull) (Cairns hickory) and Ceratopetalum apetalum (D. Don) (coachwood). Most species (except E. grandis) established successfully but slowly. Underplants suffered 9-16% mortality during thinning of the overstorey. By 2004 when aged c. 38 years, four underplanted species; F. brayleyana, S. macrophylla, F. ifflaiana and E. grandis, had attained predominant heights of 20 m and mean diameter at breast height of 25 cm or better. The presence of underplants increased total site productivity by up to 23% and did not have any detrimental effect on the development of the overwood.This experiment has demonstrated that some rainforest species will survive and grow healthily as underplants in exotic pine plantations plus produce small merchantable logs within a 38 year rotation. The results also indicated the importance of correct species selection if an underplanting option is to be pursued as some species have been a complete failure (notably G. robusta).
Resumo:
Insects can cause considerable damage in hardwood plantations and because pesticide use is controversial, future pest management may rely on manipulating insect behaviour. Insects use infochemical cues to identify and locate mates and host plants and this can be used to manipulate their behaviour and reduce pest impacts in plantations. Infochemicals include chemical signals produced by insects, such as pheromones and kairomones, or those produced by host plants as odours or volatiles that are attractive to insects. This research is learning how insects perceive and interact with chemical cues or infochemicals in their environment and how these interactions can be manipulated for monitoring and control. Pest species being investigated include the giant wood moth (Endoxyla cinerea), Culama wood moths, the eucalypt leaf beetle (Paropsis atomaria), red cedar tip moth (Hypsipyla robusta) and several longicorn wood borers. The project will contribute to new strategies for minimising damage and controlling pest densities in Queensland's hardwood plantations.
Resumo:
The two rust fungi, Ravenelia acaciae-arabicae and R. evansii, were both found on Acacia nilotica subsp. indica in southern (Tamil Nadu) and northern (Gujarat) India. R. acaciae-arabicae has been often incorrectly synonymised with R. evansii, although each has distinctive urediniospores, viz. echinulate in R. acaciae-arabicae and verruculose in R. evansii. Both species are re-described and illustrated from fresh specimens collected in India. Herbarium specimens of R. evansii from South Africa, including the holotype, were also examined. The difficulty in connecting different anamorphic spore stages to either of these teleomorphic rusts is highlighted by the presence of similar aecidia on plants of A. robusta infected with R. evansii in South Africa and on A. nilotica subsp. indica infected with R. acaciae-arabicae in India. It is not known whether these aecidial rusts represent the same species, nor is it known if they represent an aecidial stage of either R. acaciae-arabicae, R. evansii or other rusts.
Resumo:
Novel species of fungi described in the present study include the following from Australia: Neoseptorioides eucalypti gen. & sp. nov. from Eucalyptus radiata leaves, Phytophthora gondwanensis from soil, Diaporthe tulliensis from rotted stem ends of Theobroma cacao fruit, Diaporthe vawdreyi from fruit rot of Psidium guajava, Magnaporthiopsis agrostidis from rotted roots of Agrostis stolonifera and Semifissispora natalis from Eucalyptus leaf litter. Furthermore, Neopestalotiopsis egyptiaca is described from Mangifera indica leaves (Egypt), Roussoella mexicana from Coffea arabica leaves (Mexico), Calonectria monticola from soil (Thailand), Hygrocybe jackmanii from littoral sand dunes (Canada), Lindgomyces madisonensis from submerged decorticated wood (USA), Neofabraea brasiliensis from Malus domestica (Brazil), Geastrum diosiae from litter (Argentina), Ganoderma wiiroense on angiosperms (Ghana), Arthrinium gutiae from the gut of a grasshopper (India), Pyrenochaeta telephoni from the screen of a mobile phone (India) and Xenoleptographium phialoconidium gen. & sp. nov. on exposed xylem tissues of Gmelina arborea (Indonesia). Several novelties are introduced from Spain, namely Psathyrella complutensis on loamy soil, Chlorophyllum lusitanicum on nitrified grasslands (incl. Chlorophyllum arizonicum comb. nov.), Aspergillus citocrescens from cave sediment and Lotinia verna gen. & sp. nov. from muddy soil. Novel foliicolous taxa from South Africa include Phyllosticta carissicola from Carissa macrocarpa, Pseudopyricularia hagahagae from Cyperaceae and Zeloasperisporium searsiae from Searsia chirindensis. Furthermore, Neophaeococcomyces is introduced as a novel genus, with two new combinations, N. aloes and N. catenatus. Several foliicolous novelties are recorded from La Réunion, France, namely Ochroconis pandanicola from Pandanus utilis, Neosulcatispora agaves gen. & sp. nov. from Agave vera-cruz, Pilidium eucalyptorum from Eucalyptus robusta, Strelitziana syzygii from Syzygium jambos (incl. Strelitzianaceae fam. nov.) and Pseudobeltrania ocoteae from Ocotea obtusata (Beltraniaceae emend.). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.