WHIPPET: a novel tool for prioritizing invasive plant populations for regional eradication

Large geographic areas can have numerous incipient invasive plant populations that necessitate eradication. However, resources are often deficient to address every infestation. Within the United States, weed lists (either state-level or smaller unit) generally guide the prioritization of eradication of each listed species uniformly across the focus region. This strategy has several limitations that can compromise overall effectiveness, which include spending limited resources on 1) low impact populations, 2) difficult to access populations, or 3) missing high impact populations of low priority species. Therefore, we developed a novel science-based, transparent, analytical ranking tool to prioritize weed populations, instead of species, for eradication and tested it on a group of noxious weeds in California. For outreach purposes, we named the tool WHIPPET (Weed Heuristics: Invasive Population Prioritization for Eradication Tool). Using the Analytic Hierarchy Process that included expert opinion, we developed three major criteria, four sub-criteria, and four sub-sub-criteria, taking into account both species and population characteristics. Subject matter experts weighted and scored these criteria to assess the relative impact, potential spread, and feasibility of eradication (major criteria) for 100 total populations of 19 species. Species-wide population scores indicated that conspecific populations do not necessarily group together in the final ranked output. Thus, priority lists based solely on species-level characteristics are less effective compared to a blended prioritization based on both species attributes and individual population and site parameters. WHIPPET should facilitate a more efficacious decision-making process allocating limited resources to target invasive plant infestations with the greatest predicted impacts to the region under consideration.

Refining the process of agent selection through understanding plant demography and plant response to herbivory

Understanding plant demography and plant response to herbivory is critical to the selection of effective weed biological control agents. We adopt the metaphor of 'filters' to suggest how agent prioritisation may be improved to narrow our choices down to those likely to be most effective in achieving the desired weed management outcome. Models can serve to capture our level of knowledge (or ignorance) about our study system and we illustrate how one type of modelling approach (matrix models) may be useful in identifying the weak link in a plant life cycle by using a hypothetical and an actual weed example (Parkinsonia aculeata). Once the vulnerable stage has been identified we propose that studying plant response to herbivory (simulated and/or actual) can help identify the guilds of herbivores to which a plant is most likely to succumb. Taking only potentially effective agents through the filter of host specificity may improve the chances of releasing safe and effective agents. The methods we outline may not always lead us definitively to the successful agent(s), but such an empirical, data-driven approach will make the basis for agent selection explicit and serve as testable hypotheses once agents are released.

Technical highlights: Invasive plant and animal research 2009-10

Technical highlights 2009–10, with detailed progress reports on the latest invasive plant and animal research undertaken by Biosecurity Queensland, a service unit of the Department of Employment, Economic Development and Innovation.

Technical highlights: Invasive plant and animal research 2008-09

Technical highlights 2008–09, with detailed progress reports on the latest invasive plant and animal research undertaken by Biosecurity Queensland, a service unit of the Department of Employment, Economic Development and Innovation.

Technical highlights: Invasive plant and animal research 2007-08

Technical highlights 2007–08, with detailed progress reports on the latest invasive plant and animal research undertaken by Biosecurity Queensland, a service unit of the Department of Primary Industries and Fisheries.

Parallel polygon scan conversion algorithms: Performance evaluation on a shared bus architecture

In this paper, three parallel polygon scan conversion algorithms have been proposed, and their performance when executed on a shared bus architecture has been compared. It has been shown that the parallel algorithm that does not use edge coherence performs better than those that use edge coherence. Further, a multiprocessing architecture has been proposed to execute the parallel polygon scan conversion algorithms more efficiently than a single shared bus architecture.

Interior of Aenny Catzenstein's apartment; Onslo Court (?), London Architecture Residences Interior

Aenny Catzenstein is seen sitting on a sofa in the left corner of the picture

Interior of Aenny Catzenstein's apartment; Onslo Court (?), London Architecture Residences Interior

Digital Image

Interior of Aenny Catzenstein's apartment; Onslo Court (?), London Architecture Residences Interior

Digital Image

Interior of Aenny Catzenstein nee Gottschalk's cottage during WW II; Ascona, Switzerland Architecture Residences Interiors

Digital Image

Adventures in plant anatomy – not just a pigment of my imagination

An overview of teaching and research activities in the area of plant anatomy at QUT is provided. The current status of teaching of technical skills in plant anatomy is discussed briefly. Examples of applications of plant anatomy to a diverse range of fields are provided, including the crossover between art and science.

"Klo-KU-BA", Hans and Elizabeth Krakauer's first marital apartment in the basement of the Jewish Hospital; Hannover, Germany Architecture; Residences; Interior

Digital Image

Relative host plant species use by the lantana biological control agent Aconophora compressa (Membracidae) across its native and introduced ranges

Aconophora compressa Walker (Hemiptera: Membracidae) was released in 1995 against the weed lantana in Australia, and is now found on multiple host plant species. The intensity and regularity at which A. compressa uses different host species was quantified in its introduced Australian range and also its native Mexican range. In Australia, host plants fell into three statistically defined categories, as indicated by the relative rates and intensities at which they were used in the field. Fiddlewood (Citharexylum spinosum L.: Verbenaceae) was used much more regularly and at higher densities than any other host sampled, and alone made up the first group. The second group, lantana (Lantana camara L.: Verbenaceae; pink variety) and geisha girl (Duranta erecta L.: Verbenaceae), were used less regularly and at much lower densities than fiddlewood. The third group, Sheena’s gold (another variety of D. erecta), jacaranda (Jacaranda mimosifolia D. Don: Bignoniaceae) and myoporum (Myoporum acuminatum R. Br.: Myoporaceae), were used infrequently and at even lower densities. In Mexico, the insect was found at relatively low densities on all hosts relative to those in Australia. Densities were highest on L. urticifolia, D. erecta and Tecoma stans (L.) Juss. ex Kunth (Bignoniaceae), which were used at similar rates to one another. It was found also on a few other verbenaceous and non-verbenaceous host species but at even lower densities. The relative rate at which Citharexylum spp. and L. urticifolia were used could not be assessed in Mexico because A. compressa was found on only one plant of each species in areas where these host species co-occurred. The low rate at which A. compressa occurred on fiddlewood in Mexico is likely to be an artefact of the short-term nature of the surveys or differences in the suites of Citharexylum and Lantana species available there. These results provide further incentive to insist on structured and quantified surveys of non-target host use in the native range of potential biological control agents prior to host testing studies in quarantine.

Potential gains through selecting for resistance in spotted gum to Quambalaria pitereka

Abstract Quambalaria shoot blight, caused by the fungus Quambalaria pitereka, is a serious disease affecting the expanding eucalypt plantation estate in subtropical and tropical eastern Australia. Trees that are severely infected are often multi-stemmed and stunted and infection of young trees may give rise to poor form in mature trees. A spotted gum clonal trial provided the opportunity to investigate the impact of the disease on tree growth and factors influencing tree architecture (tree form), which affects wood quality. We measured the effect that Q. pitereka infection during plantation establishment (up to 6 months old) has on growth and tree architecture and productivity to age 3 years. Our results show that the pathogen has a significant impact on trees at plantation establishment, which results in a negative impact on wood quality, potentially reducing merchantable value at final harvest. Tree growth and form was significantly improved where germplasm with low susceptibility to Q. pitereka infection was used.