~measurements of transition probabilities in some middle weight nuclei

Measuring level schemes of Nb-92 and Nb-94 by /p,n/ reaction on separated zirconium target

An Angular Correlation Test of Time Reversal Invariance

Gamma-ray angular correlation experiment of time reversal invarianc

Angular Correlation of Cascade Gamma Rays in 94nb

Angular correlation of cascade gamma rays in niobiu

Impacts and Implications of Co-occurring Invasive Plant Species

The anthropogenic spread of species is a potent form of global change that impacts the population dynamics of native species, the composition of native communities, and the functioning of ecosystems. As the reorganization of species around the globe continues unabated, there is an increasing likelihood that habitats will contain co-occurring invaders. In this dissertation, I emphasize the need to study co-occurring invasive plants by juxtaposing the relative occurrence of multiple versus single invasive plants in important conservation habitats to the relative occurrence of published studies that consider the impacts of single versus multiple invasive plants. I found that over two-thirds of conservation habitats are multiply invaded while less that one-third of studies consider the impacts of co-occurring invaders and only 6% of studies focused on invasive plant interactions. To address this conservation-research mismatch, I use an observational study of the above- and belowground impacts of two co-occurring invasive woody plants among plots containing both shrubs, each species singly, or lacking both species. I found that subdominant invasive plant richness in plots with both invaders was twice as high as in plots with either invader singly and that β [beta]-glucosidase activity, a carbon-degrading extracellular soil enzyme, was three times greater than in control plots. These findings indicate that co-occurring invaders can have additive and non-additive effects compared to when they are found singly. Next, using a greenhouse experiment, I asked how interactions within native and nonnative plant communities affected their response to species gains and losses. I constructed phylogenetically paired native and nonnative plant communities that varied in species richness and measured above- and belowground productivity and seedling establishment of woody species. I found that native and nonnative plant communities differed in their overall biomass allocation patterns, the mechanisms driving community response to species losses, and the receptivity of communities to species gains. Overall, my work implies that the impacts of co-occurring invasive plant species are not necessarily predictable based upon single-invader impacts or interactions of closely related native species

Eating Invaders: Managing Biological Invasions with Fork and Knife?

As the public, academy, government, and private sector all turn increased attention to food systems, new ideas constantly emerge for healthy, sustainable, and just innovations in growing, marketing, and eating food. “Invasivory” — eating invasive species — is one such idea. Biological invasions occur when humans transport an organism from its ecosystem of origin into a new ecosystem and that organism adapts to its new location, spreading widely from the site of introduction. Invasive species can cause significant ecological, economic, and public health damage. Crops, homes, and native species are all at risk. “Invasivores,” as the proponents of invasivory are called, recognize the many dangers of invasive species, and they propose bringing invaders into the food system. Whether as commodities, value-added artisanal goods, game, or any other object of the system, the argument is the same: the food system is a powerful force and human eating habits can effect dramatic change as is evidenced from the many species that humans have eaten to near extinction. What was bad for the passenger pigeon or Atlantic Cod is good for European starlings or Asian carp. Put differently, humans can address the problems of invasive species by eating them. Businesses, governments, and academics now promote the invasivore movement. In New Haven, Connecticut, Chef Bun Lai of Miya’s Sushi is one of the nation’s leading invasivores, and he serves a number of invasive dishes in his restaurant. Governments as different as Michigan and Florida have started campaigns to promote consumption of invasive fish. Professors and graduate students from Vermont to Indiana host websites touting the ecological benefits. Unfortunately, there are compelling arguments against the invasivore movement. This article will describe the rationale and breadth of the eating invaders movement followed by a series of critiques. For example, both food safety and environmental laws may prohibit the sale of many invasive species. Birth and death rates might make it impossible for consumption to have any impact on populations. Social expectations and economic standards are likely to interfere with complete eradication of any popular food source. The invasivore movement is captivating and, to its credit, is a tool for educating the public about an important issue. However, it is unlikely to be effective and the more popular it becomes, the more likely it is to exacerbate ecological problems. For this reason, a more critical and public debate of the idea is necessary

Invasive Species: To eat or not to eat, that is the question

Managing invasive species is a current challenge for biodiversity conservation. A recurring recent suggestion is that by harvesting nonnatives for human consumption, people can control invasive populations. Even though humans may be able to control or eradicate certain populations of nonnative species by harvesting them as food sources, several caveats should be considered before starting these programs. A prominent problem is that creating a market engenders pressure to maintain that problematic species. Also, if the target species becomes an economic resource, people may try to recreate that market in previously uninvaded regions. Using invasive species as an economic resource may trigger the local community to protect these harmful species, to facilitate their incorporation into the local culture, and can generate severe management problems. As with other management programs, managers must know if the harvest actually reduces the target population. Mortality could produce a reduction in the population size or growth, or it could be compensatory, in which case removal of the harvested individuals would not affect population growth. However, in addition to possible control, there may be several benefits of this approach, including an opportunity for public outreach. Projects aiming at controlling invasives through human consumption should be carefully examined, as they may produce results opposite to those proposed.Fil: Nuñez, Martin Andres. University of Tennessee; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Kuebbing, Sara. University of Tennessee; Estados UnidosFil: Dimarco, Romina Daniela. University of Tennessee; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Simberloff, Daniel. University of Tennessee; Estados Unido

We do not want to “cure plant blindness” we want to grow plant love

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150580/1/ppp310062_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150580/2/ppp310062.pd

Plant-soil interactions promote co-occurrence of three nonnative woody shrubs

Abstract. Ecosystems containing multiple nonnative plant species are common, but mechanisms promoting their co-occurrence are understudied. Plant-soil interactions contribute to the dominance of singleton species in nonnative ranges because many nonnatives experience stronger positive feedbacks relative to co-occurring natives. Plant-soil interactions could impede other nonnatives if an individual nonnative benefits from its soil community to a greater extent than its neighboring nonnatives, as is seen with natives. However, plant-soil interactions could promote nonnative co-occurrence if a nonnative accumulates beneficial soil mutualists that also assist other nonnatives. Here, we use greenhouse and field experiments to ask whether plant-soil interactions (1) promote the codominance of two common nonnative shrubs (Ligustrum sinense and Lonicera maackii ) and (2) facilitate the invasion of a lesscommon nonnative shrub (Rhamnus davurica) in deciduous forests of the southeastern United States. In the greenhouse, we found that two of the nonnatives, L. maackii and R. davurica, performed better in soils conditioned by nonnative shrubs compared to uninvaded forest soils, which suggests that positive feedbacks among co-occurring nonnative shrubs can promote continued invasion of a site. In both greenhouse and field experiments, we found consistent signals that the codominance of the nonnatives L. sinense and L. maackii may be at least partially explained by the increased growth of L. sinense in L. maackii soils. Overall, significant effects of plant-soil interactions on shrub performance indicate that plant-soil interactions can potentially structure the co-occurrence patterns of these nonnatives

Native diversity buffers against severity of non-native tree invasions

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4. Here, leveraging global tree databases5,6,7, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions.EEA Santa CruzFil: Delavaux, Camille S. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Crowther, Thomas W. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Zohner, Constantin M. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Robmann, Niamh M. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Lauber, Thomas. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: van den Hoogen, Johan. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Kuebbing, Sara. Yale University. The Forest School at The Yale School of the Environment; Estados UnidosFil: Liang, Jingjing. Purdue University. Department of Forestry and Natural Resources; Estados UnidosFil: de-Miguel, Sergio. University of Lleida. Department of Crop and Forest Sciences; EspañaFil: de-Miguel, Sergio. Joint Research Unit CTFC–AGROTECNIO–CERCA; EspañaFil: Nabuurs, Gert-Jan. Wageningen University and Research; Países BajosFil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Maynard, Daniel S. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Maynard, Daniel S. University College London. Department of Genetics, Evolution, and Environment; Reino Unid

Native diversity buffers against severity of non-native tree invasions

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species$^{1,2}$. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies$^{3,4}$. Here, leveraging global tree databases$^{5–7}$, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions