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Invasion syndromes:hypotheses on relationships among invasive species attributes and characteristics of invaded sites

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Journal of Arid Land 2013年第3期5卷 275-283页

作者： Lora B PERKINS Robert S NOWAK Department of Natural Resource Management South Dakota State UniversityBrookings SD 57007USA Department of Natural Resources & Environmental Science University of NevadaReno NV 89557USA

As invasion science accepts that there is no single causal factor for biological invasion, the identification of groups of traits that are often associated, or ＂syndromes＂, is a logical move forward. Invasion syndromes are proposed to identify suites of site conditions （biotic and environmental） that render a site vulnerable to invasion by different types of invaders. This paper proposed four invasion syndromes which relate invader attributes （competitive ability, niche construction, phenotypic plasticity, and phenological niche separation） to the biotic characteristics （biodiversity and enemies） and environmental conditions （resource abundance and fluctuation） of invaded sites. The four invasion syndromes described in this paper are a development of hypotheses of how the many factors that influence species invasion might be associated. Invasion Syndrome 1 proposes that sites with relatively high resource abundance and high diversity should be vulnerable to invasion by species with high competitive ability. Invasion Syndrome 2 hypothesizes that sites with relatively low resource abundance and low diversity should be vulnerable to invasion by species with niche construction ability. Invasion Syndrome 3 postulates that sites with moderate or fluctuating resources and moderate diversity should be vulnerable to invasion by species with high phenotypic plasticity. Invasion Syndrome 4 hypothesizes that species introduced into a site where it has phenological niche separation from natives will not have to contend with interference from the biotic community at a site （diversity or natural enemies） and may invade where ever site environmental conditions suit its life history. Further work is needed to support, contradict, or refine these hypotheses and almost certainly will identify more invasion syndromes.

关键词： non-native competitive ability niche construction ecosystem engineering phenotypic plasticity phenological niche separation

Increased Benthic Algal Primary Production in Response to the Invasive Zebra Mussel (Dreissena polymorpha) in a Productive ecosystem,Oneida Lake,New York

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Journal of Integrative Plant Biology 2008年第11期50卷 1452-1466页

作者： Rebecca K.Cecala Christine M.Mayer Kimberly L.Schulz Edward L.Mills Biology Department Syracuse University Biology Deptartment Department of Environmental Sciences and Lake Erie Center University of Toledo State University of New York School of Environmental Science and Forestry Cornell Biological Field Station and Department of Natural Resources Cornell University

Increased water clarity associated with zebra mussel （Dreissena polymorpha） populations may favor benthic algal primary production in freshwater systems previously dominated by pelagic phytoplankton production. While zebra mussel-mediated water clarity effects on benthic primary production have been implicated in published reports, few production estimates are available. This study estimates benthic primary production in Oneida Lake, NY before and after zebra mussel invasion （1992）, using measured photosynthetic parameters （P^Bmax, α^β and β） from sampled benthic algal communities. In the summers of 2003 and 2004, primary production was measured as O2 evolution from algal communities on hard （cobble） and soft （sediment） substrate from several depths. We also backcast estimates of benthic primary production from measurements of light penetration since 1975. Estimates of whole-lake epipelic and epilithic algal primary production showed a significant （4%） increase and exhibited significantly less interannual variability subsequent to the establishment of zebra mussels. We applied our model to two lakes of differing trophic status; the model significantly overestimated benthic primary production in a hypereutrophic lake, but there was no significant difference between the actual and predicted primary production values in the oligotrophic lake. The hypereutrophic lake had higher zebra mussel densities than Oneida （224 vs. 41 per sample respectively）. Though total community respiration （measured in total darkness） was factored into our model predictions of production, our model may need modification when heterotrophic respiration is a large portion of total community metabolism.

关键词： Dreissena ecosystem engineering nonindigenous species Oneida Lake periphyton primary production.

Burrowing Richardson's ground squirrels affect plant seedling assemblages via environmental but not seed bank changes

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Current Zoology 2020年第3期66卷 219-226页

作者： Levi J.Newediuk James F.Hare Department of Biological Sciences University of ManitobaWinnipegManitobaCanada R3T 2N2

In grassland ecosystems,burrowing mammals create disturbances,providing habitat for animal species and increasing plant community *** investigated whether seedling assemblages on Richardson's ground squirrel Urocitellus richardsonii mounds result from seed rearrangement or environmental changes that favor germination of certain species over *** test whether ground squirrels rearrange the seed bank by burrowing,we compared seed compositions among mounds,burrows,and undisturbed *** test whether ground squirrels change environmental conditions,we compared soil nitrate and bare ground cover on and off *** also compared seedlings that germinated on mounds with seedlings that germinated on artificial disturbances from which we removed aboveground *** nitrate and bare ground cover were significantly higher on mounds than artificial *** seed richness and abundance did not differ among mounds,burrows,and undisturbed soil,seedling richness was reduced on mounds relative to artificial *** disturbance favors seedlings that can capitalize on bare ground availability but are less able to immobilize nitrate,as opposed to perennial species that immobilize more nitrate but take longer to *** results suggest that Richardson's ground squirrels act as ecosystem engineers,although future research following succession on ground squirrel mounds is necessary to understand how they influence plant communities past the seedling stage.

关键词： burrowing disturbance ecosystem engineering Richardsons ground squirrel seed bank seedling species composition

Environmentally applied nucleic acids and proteins for purposes of engineering changes to genes and other genetic material

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Biosafety and Health 2019年第3期1卷 113-123页

作者： Jack A.Heinemann Sophie Walker Centre for Integrated Research in Biosafety and School of Biological Sciences University of CanterburyChristchurchNew Zealand Defence Technology Agency AucklandNew Zealand

In this article we summarize the development of vehicles for penetrating living cells,tissue and organisms with nucleic acids(DNA and RNA)and proteins that damage or repair *** purpose in doing so is to provide an assessment of the potential for these technologies to unintentionally cause harm to human health or the environment or to be retasked with an intention to cause *** new types of biological-molecule-based products are being developed for use in medicine,agriculture and food production or *** first type are genetically modified organisms,such as those that express *** produce molecules and that are difficult to alter at scale after *** of this type are usually evaluated by both food and environmental *** second type comprises topical chemical or physical *** of these are in pre-commercial testing *** applied products use nucleic acids and/or proteins wherein the active biological is transferred by contact,ingestion or *** a survey of the research and patent literature we suggest that chemical formulations and physical manipulations that can be used to ferry nucleic acid and protein cargo into cells,tissues or organisms could be assembled de novo or repurposed from existing commercial products and loaded with proteins and/or nucleic acids designed using publicly available genome *** actives may evade risk assessment and regulatory review because they are often excluded from the category of hazardous chemicals and are actively being excluded as agents of genetic *** emerging gap in oversight could lead to either dual use appropriation or unintended harm to human health or the environment.

关键词： RNAi Genome editing Penetration technologies ecosystem engineering Transient expression Parental RNAi Topical dsRNA