101 research outputs found
A multi-scale modelling framework to guide management of plant invasions in a transboundary context
Background
Attention has recently been drawn to the issue of transboundary invasions, where species introduced and naturalized in one country cross international borders and become problematic in neighbouring countries. Robust modelling frameworks, able to identify the environmental drivers of invasion and forecast the current and future potential distribution of invasive species, are needed to study and manage invasions. Limitations due to the lack of species distribution and environmental data, or assumptions of modelling tools, often constrain the reliability of model predictions.
Methods
We present a multiscale spatial modelling framework for transboundary invasions, incorporating robust modelling frameworks (Multimodel Inference and Ensemble Modelling) to overcome some of the limitations. The framework is illustrated using Hakea sericea Schrad. (Proteaceae), a shrub or small tree native to Australia and invasive in several regions of the world, including the Iberian Peninsula. Two study scales were considered: regional scale (western Iberia, including mainland Portugal and Galicia) and local scale (northwest Portugal). At the regional scale, the relative importance of environmental predictors sets was evaluated and ranked to determine the main general drivers for the species distribution, while the importance of each environmental predictor was assessed at the local scale. The potential distribution of H. sericea was spatially projected for both scale areas.
Results
Model projections for western Iberia suggest that a large area is environmentally suitable in both Portugal and Spain. Climate and landscape composition sets were the most important determinants of this regional distribution of the species. Conversely, a geological predictor (schist lithology) was more important in explaining its local-scale distribution.
Conclusions
After being introduced to Portugal, H. sericea has become a transboundary invader by expanding in parts of Galicia (Spain). The fact that a larger area is predicted as environmentally suitable in Spain raises concerns regarding its potential continued expansion. This highlights the importance of transboundary cooperation in the early management of invasions. By reliably identifying drivers and providing spatial projections of invasion at multiple scales, this framework provides insights for the study and management of biological invasions, including the assessment of transboundary invasion risk.This work was funded by FEDER funds through the Operational Programme
for Competitiveness Factors - COMPETE and by National Funds through
FCT - Foundation for Science and Technology under the project PTDC/AAGMAA/4539/2012
/ FCOMP-01-0124-FEDER-027863 (IND_CHANGE). J. Vicente
is supported by POPH/FSE funds and by National Funds through FCT -
Foundation for Science and Technology through Post-doctoral grant
SFRH/BPD/84044/2012. D.M. Richardson acknowledges support from the
DST-NRF Centre of Excellence for Invasion Biology and the National
Research Foundation (grant 85417).info:eu-repo/semantics/publishedVersio
Recommended from our members
Plantwide Energy Assessment of a Sugarcane Farming and Processing Facility
A plantwide energy assessment was performed at Hawaiian Commercial & Sugar Co., an integrated sugarcane farming and processing facility on the island of Maui in the State of Hawaii. There were four main tasks performed for the plantwide energy assessment: 1) pump energy assessment in both field and factory operations, 2) steam generation assessment in the power production operations, 3) steam distribution assessment in the sugar manufacturing operation, and 4) electric power distribution assessment of the company system grid. The energy savings identified in each of these tasks were summarized in terms of fuel savings, electricity savings, or opportunity revenue that potentially exists mostly from increased electric power sales to the local electric utility. The results of this investigation revealed eight energy saving projects that can be implemented at HC&S. These eight projects were determined to have potential for $1.5 million in annual fuel savings or 22,337 MWh equivalent annual electricity savings. Most of the savings were derived from pump efficiency improvements and steam efficiency improvements both in generation and distribution. If all the energy saving projects were implemented and the energy savings were realized as less fuel consumed, there would be corresponding reductions in regulated air pollutants and carbon dioxide emissions from supplemental coal fuel. As HC&S is already a significant user of renewable biomass fuel for its operations, the projected reductions in air pollutants and emissions will not be as great compared to using only coal fuel for example. A classification of implementation priority into operations was performed for the identified energy saving projects based on payback period and ease of implementation
Fractal Adaptation to Complexity: A Non-state Perspective. The Genetic Resources and Human Trafficking
Looking at patterns of non-state involvement in regime complexe
Combinatorial Redesign of the DNA Binding Specificity of a Prokaryotic Helix-Turn-Helix Repressor
Redesign of the bacteriophage 434 Cro repressor was accomplished by using an in vivo genetic screening system to identify new variants that specifically bound previously unrecognized DNA sequences. Site-directed, combinatorial mutagenesis of the 434 Cro helix-turn-helix (HTH) motif generated libraries of new variants which were screened for binding to new target sequences. Multiple mutations of 434 Cro that functionally converted wild-type (wt) 434 Cro DNA binding-sequence specificity to that of a λ bacteriophage-specific repressor were identified. The libraries contained variations within the HTH sequence at only three positions. In vivo and in vitro analysis of several of the identified 434 Cro variants showed that the relatively few changes in the recognition helix of the HTH motif of 434 Cro resulted in specific and tight binding of the target DNA sequences. For the best 434 Cro variant identified, an apparent K(d) for λ O(R)3 of 1 nM was observed. In competition experiments, this Cro variant was observed to be highly selective. We conclude that functional 434 Cro repressor variants with new DNA binding specificities can be generated from wt 434 Cro by mutating just the recognition helix. Important characteristics of the screening system responsible for the successful identifications are discussed. Application of the techniques presented here may allow the identification of DNA binding protein variants that functionally affect DNA regulatory sequences important in disease and industrial and biotechnological processes
- …