Non-native Plant Invasions Research Articles

The Sky Is Not the Limit: Use of a Spray Drone for the Precise Application of Herbicide and Control of an Invasive Plant in Managed Wetlands

Controlling non-native plant invasions that reduce the quality of preferred wetland habitats is a challenge for many wetland managers. Herbicides may be used to control invasions, but it may be difficult to find effective application methods depending on the terrain. Manned aircraft cover large patches, but aerial use is limited by high costs, weather conditions, and overspray concerns. Ground applications target smaller patches, but their effectiveness may be limited by accessibility, labor costs, and applicator health concerns. Considering these difficulties, unmanned aerial systems (UAS) have emerged as a viable alternative for more effectively treating plant invasions. We tested the use of a specialized UAS to control invasive perennial pepperweed (Lepidium latifolium) in Suisun Marsh in northern California, USA. This “spray drone” flew at an altitude of 2–3 m, a speed of 24 kmph, and applied herbicide with a swath width of 6 m. We applied herbicide with the spray drone to treat small patches before they expanded. To delineate invasive patch boundaries, we first flew a survey drone with a 4K resolution camera to detect emerging plants with color imagery and conduct an initial classification analysis. We subsequently visited areas with suspected invasive patches based on the classification, and observers manually confirmed the presence of the invasive species. We then flew the spray drone on transects to treat the patches and examined the results with post-treatment survey drone imagery and plots along ground transects. In total, we sprayed 14 ha of Lepidium across eight sites and found that 87% of the Lepidium was discernibly affected by our herbicide treatment. Furthermore, we measured the overspray, which was substantially less than that reported for other aerial application methods such as helicopter-spraying, and our estimated operational costs were lower. Our results indicated that applying remote-sensing imagery for the identification of invasive species patches and the use of a spray drone for treatment may be an effective means of controlling invasive plants with high precision at a reasonable cost. In the near future, a unified UAS system that both identifies invasive species and then treats them in a single pass should be a promising goal for early detection and rapid response in wetland management.

A bench-top Dark-Root device built with LEGO® bricks enables a non-invasive plant root development analysis in soil conditions mirroring nature.

Roots are the hidden parts of plants, anchoring their above-ground counterparts in the soil. They are responsible for water and nutrient uptake and for interacting with biotic and abiotic factors in the soil. The root system architecture (RSA) and its plasticity are crucial for resource acquisition and consequently correlate with plant performance while being highly dependent on the surrounding environment, such as soil properties and therefore environmental conditions. Thus, especially for crop plants and regarding agricultural challenges, it is essential to perform molecular and phenotypic analyses of the root system under conditions as near as possible to nature (#asnearaspossibletonature). To prevent root illumination during experimental procedures, which would heavily affect root development, Dark-Root (D-Root) devices (DRDs) have been developed. In this article, we describe the construction and different applications of a sustainable, affordable, flexible, and easy to assemble open-hardware bench-top LEGO® DRD, the DRD-BIBLOX (Brick Black Box). The DRD-BIBLOX consists of one or more 3D-printed rhizoboxes, which can be filled with soil while still providing root visibility. The rhizoboxes sit in a scaffold of secondhand LEGO® bricks, which allows root development in the dark and non-invasive root tracking with an infrared (IR) camera and an IR light-emitting diode (LED) cluster. Proteomic analyses confirmed significant effects of root illumination on barley root and shoot proteomes. Additionally, we confirmed the significant effect of root illumination on barley root and shoot phenotypes. Our data therefore reinforces the importance of the application of field conditions in the lab and the value of our novel device, the DRD-BIBLOX. We further provide a DRD-BIBLOX application spectrum, spanning from investigating a variety of plant species and soil conditions and simulating different environmental conditions and stresses, to proteomic and phenotypic analyses, including early root tracking in the dark.

Predicting vulnerability of forest patches to invasion by non-native plants for landscape scale management.

As a leading cause of forest health degradation, non-native invasive plant species are a key focus for many forest management and conservation efforts. These efforts come at a high price for resource limited agencies and organizations making cost effectiveness an important objective of invasion response plans. In this paper we present an approach to guide the prioritization of locations for invasion management using species distribution models that account for the non-equilibrium of invasive species distributions and use readily available land use data as the primary explanatory variables. This approach takes advantage of the relatively high spatial resolution, as well as the broad, continuous geographic coverage, of land use data to provide results at a landscape scale relevant to practitioners responsible for invasive species management. In our example from northern Virginia, we simultaneously modeled a suite of invasive plant species to identify common indicators of invasion. We found that the proportions of surrounding non-forested land use types (grasses, crops, and development) were the most common and strongest indicators of invasion risk. These outcomes can guide managers of large protected areas to focus on major divides between forest and non-forest land over linear disturbances. We also found useful species-specific traits that can inform specific management actions. Additionally, we demonstrate through a case study how organizations that manage multiple smaller properties can take advantage of the projected distribution maps when considering acquiring or administering properties.

The peroxidase response of Alternanthera philoxeroides (Alligator Weed) and Nasturtium officinale (Watercress) to heavy metal exposure.

We examined the effects of copper and lead on the antioxidant enzyme response of Alternanthera philoxeroides and Nasturtium officinale using a benchtop luminometer. Alternanthera philoxeroides is a nonnative invasive plant species that has spread throughout the wetland ecosystem in the southern part of the USA. Its invasion is facilitated by its ability to thrive in a wide range of abiotic conditions. Nasturtium officinale is an aquatic plant that is sensitive to relatively low amounts of pollution and is most commonly found in springs and shallow bodies of water. While A. philoxeroides tolerates organic pollution and heavy metals, N. officinale exhibits stress at low levels of pollution. Alternanthera philoxeroides antioxidant enzyme production was unaffected by increasing concentrations of both copper and lead. The antioxidant enzyme response of N. officinale showed a significant increase when plants were exposed to 10 and 25ppm lead. Endogenous peroxidase concentrations of the control plants were also compared showing that A. philoxeroides possessed a significantly higher concentration of peroxidases than N. officinale. We hypothesize that a higher endogenous peroxidase concentration may be a mechanism that hyperaccumulator plants use to tolerate inhospitable concentrations of copper and lead.

Competition effect exerted by two nonnative invasive plant species on a native under contrasting conditions of resource availability

Competition effect exerted by two nonnative invasive plant species on a native under contrasting conditions of resource availability

Field scale biodiversity in relation to the intensity grade of agricultural practices on dairy farms

The present study has been aimed at finding relationships, at the field level, between indicators of the intensity of agricultural practices, computed as carbon footprint (CF), nutrient balance, and intensity use of agrochemicals and indicator-species groups, selected to be representative of biodiversity, such as herbaceous vascular plants, carabid beetles (Coleoptera: Carabidae), and butterflies (Lepidoptera: Papilionoidea). Fields were selected and monitored over 2 years, on six adjacent dairy farms, to represent three cropping systems and five different intensity levels of agricultural practices: mono-cropped maize with high (M-high) or low (M-low) chemical pressure; maize in rotation (M-rot) with alfalfa (Alf) and low chemical pressure; herbaceous strips with no chemical pressure (Strip). Plants (through whole field monitoring), carabids (through pitfall traps) and butterflies (through transects) were sampled in fields and field margins; CF was computed by considering emissions linked to direct and indirect CO2, CH4 and N2O; N, P2O5 and K2O balances, as the difference between the total imported and exported nutrients, were computed at the field level; the agrochemical use intensity was assessed by frequency of application and Load indexes for non-target organisms. The CF was lower in Alf (84 kg CO2-eq/t DM) and Strip (11 kg CO2-eq/t DM) than in all the maize fields (6357, 4499, and 4059 kg CO2-eq/t DM for M-high, M-low and M-rot respectively). The highest nitrogen surplus was observed in M-high (+413 kg/ha), while it was intermediate for M-low and M-rot and the lowest in Alf. The M-high fields showed the highest load indexes for all the selected non-target organisms (mammals, fishes, algae, bees, and earthworms), whereas the lowest load indexes were observed in Strip and Alf. Overall 179 herbaceous species (20 invasive), 45 carabid species, and 39 butterfly species were observed over the 2 years study. The numbers of herbaceous species, of species of interest for pollinators, and of plant families were higher in Strip, Alf and M-rot, whereas the non-native and invasive plants were higher in M-high and Strip. The highest number of carabid species was observed in the Alf and M-low fields, and in Alf, M-low and Strip when the field margins were considered. The highest number of butterfly species was observed in M-rot, Alf and Strip when a single year was considered, whereas it was observed in Alf when the data were pooled over two years. The CF (kg CO2-eq/ha) had a marked negative effect on the plant (r = −0.90, P 0.01), carabid (r = −0.90, P 0.01) and butterfly (r = −0.79, P 0.01) species richness, as well as it positively affected the proportion of non-native invasive plants (r = 0.76, P 0.01). The N surplus negatively affected plant (r = −0.71, P 0.01) and butterfly (r = −0.81, P 0.01) species richness, while positively correlated with proportion of non-native invasive plants observed in the fields (r = 0.80, P 0.01). When all the species from the three indicator-species groups were considered together and plotted against CF (kg CO2-eq/t DM), and against N surplus (kg N/ha), great coefficients of determination were found (R2 = 0.81 and R2 = 0.88, respectively). The current findings provide evidence that well-implemented and diverse cropping systems constitute a benefit for biodiversity at the farm level, without compromising the yield potential, thus offering indications to European decision makers on how to design more specific agri-environmental measures.

Carabid specialists respond differently to nonnative plant invasion in urban forests

Carabid specialists respond differently to nonnative plant invasion in urban forests

Characterization of Potato Tuber Tissues Using Spatialized MRI T2 Relaxometry.

Magnetic Resonance Imaging is a powerful non-destructive tool in the study of plant tissues. For potato tubers, it greatly assists the study of tissue defects and tissue evolution during storage. This paper describes the MRI analysis of potato tubers with internal defects in their flesh tissue at eight sampling dates from 14 to 33 weeks after harvest. Spatialized multi-exponential T2 relaxometry was used to generate bi-exponential T2 maps, coupled with a classification scheme to identify the different T2 homogeneous zones within the tubers. Six classes with statistically different relaxation parameters were identified at each sampling date, allowing the defects and the pith and cortex tissues to be detected. A further distinction could be made between three constitutive elements within the flesh, revealing the heterogeneity of this particular tissue. Relaxation parameters for each class and their evolution during storage were successfully analyzed. The work demonstrated the value of MRI for detailed non-invasive plant tissue characterization.

Drought reduces invasive grass performance by disrupting plant-microbe interactions that enhance plant nitrogen supply.

Non-native invasive plants can promote their dominance in novel ecosystems by accelerating soil nutrient cycling via interactions with decomposer microbes. Changes in abiotic conditions associated with frequent or prolonged drought may disrupt these interactions, but the effects of disruption on invasive plant performance and the underpinning mechanisms are poorly understood. Here, we used rainout shelters in an experimental field setting to test the hypothesis that drought reduces invasive plant performance by reducing microbial metabolic activity, resulting in decreased nitrogen flow to plants. We imposed growing season drought on populations of the exotic grass Microstegium vimineum, a widespread invasive plant in eastern deciduous forests, and quantified effects on aboveground and belowground biomass, and carbon (C) and nitrogen (N) cycling among plants, decomposers, and soil. Drought resulted in a 24% decrease in soil respiration, a 16% decrease in phenol oxidase enzyme activity, a 12% decrease in dissolved organic N concentration, and a decrease in the C:N ratio of particulate organic matter, suggesting reduced microbial metabolic activity and nutrient mining of soil organic matter. Drought also reduced aboveground Microstegium biomass 33% and increased Microstegium leaf C:N ratio, consistent with a decline in plant N uptake. We conclude that drought can reduce the performance of existing invasive species populations by suppressing plant-microbe interactions that increase nitrogen supply to plants, which may have consequences for the persistence of invasive plants under hydrologic change.

Fluctuations in resource availability shape the competitive balance among non-native plant species.

Fluctuating resource availability plays a critical role in determining non-native plant invasions through mediating the competitive balance between non-native and native species. However, the impact of fluctuating resource availability on interactions among non-native species remains largely unknown. This represents a barrier to understanding invasion mechanisms, particularly in habitats that harbor multiple non-native species with different responses to fluctuating resource availability. To examine the responses of non-native plant species to nutrient fluctuations, we compared the growth of each of 12 non-native species found to be common in local natural areas to nutrients supplied at a constant rate or supplied as a single large pulse in a pot experiment. We found that seven species produced more biomass with pulsed nutrients compared to constant nutrients (hereafter "benefitting species"), while the other five species did not differ between nutrient enrichment treatments (hereafter "non-benefitting species"). To investigate how nutrient fluctuations influence the interactions among non-native plant species, we established experimental non-native communities in the field with two benefitting and two non-benefitting non-native species. Compared with constant nutrient supply, the single large pulse of nutrient did not influence community biomass, but strongly increased the biomass and cover of the benefitting species and decreased those of the non-benefitting species. Furthermore, the benefitting species had higher leaf N content and greater plant height when nutrients were supplied as a single large pulse than at a constant rate, whereas the non-benefitting species showed no differences in leaf N content and were shorter when nutrients were supplied as a single large pulse than at a constant rate. Our results add to the growing evidence that the individual responses of non-native species to nutrient fluctuation are species-specific. More importantly, benefitting species were favored by nutrients coming in a pulse, while non-benefitting ones were favored by nutrients coming constantly when they grew together. This suggests that nutrient fluctuations can mediate the competitive balance among non-native plants and may thus determine their invasion success in a community harboring multiple non-native plant species.

Identifying limitations for invasion: the effect of phosphorus availability on the growth of the non-native tree, Tipuana tipu

Context Despite being a crucial factor in plant growth and fitness, the nutritional requirements of non-native invasive plants are poorly understood and rarely considered when assessing invasion risk; yet, they are particularly relevant in many parts of the world with nutrient-poor soils. Aims We investigated the growth response of a native South American tree species (Tipuana tipu), to soil concentrations of phosphorus (P). T. tipu is widely introduced in some regions of western Australia and South Africa, and we aimed to determine whether soil P availability constrains establishment, naturalisation or invasion of the species. Methods We grew T. tipu (Benth.) Kuntze (Fabaceae), a species that is invasive in some regions, from seed in a glasshouse. All treatments were supplied baseline nutrients, and P from 0 to 640 μg P g−1 dry substrate. Plant height and the number of mature leaves were recorded regularly. Plant biomass, P, and nitrogen (N) concentrations were analysed following destructive harvest. Key results Phosphorus availability had a significant effect on all measured aspects of plant growth. Seed P resources were sufficient to support growth for about 7 weeks, with plants at very low soil P availability (≤5 μg P g−1 dry soil) unable to sustain growth beyond that time. P-toxicity symptoms were observed when substrate P exceeded optimum concentrations (40–160 μg P g−1 dry soil). Conclusions Growth of young T. tipu seedlings was very slow at very low soil P concentrations. Under these conditions, seeds may germinate, and seedlings may survive for a short time, but self-sustaining populations are unlikely to be established. Our study adds to a growing body of research that shows that nutrient requirements of introduced plants and soil nutrient availability influence invasion risk and should be considered in risk assessments for managing species invasions at the landscape level.

Restored wetlands are greatly influenced by hydrology and non-native plant invasion

Restored wetlands are greatly influenced by hydrology and non-native plant invasion

Invasive Plants Have Higher Resistance to Native Generalist Herbivores Than Exotic Noninvasive Congeners.

Research on the invasive plant Phytolacca americana (L.) mostly focuses on its medicinal value and enrichment of heavy metals. However, little is known regarding its impact on native herbivorous insects. In this study, we explored the effects of P. americana and the exotic noninvasive Phytolacca icosandra (L.) on the Spodoptera litura (Fabricius) (native tobacco cutworm) via bioassay, oviposition preference, detoxifying enzyme activity analysis, and phytochemical determination. We found that the oviposition preference index (OPI) of S. litura feeding on P. icosandra was higher than that of P. americana. The developmental duration of S. litura feeding on P. icosandra was shorter than that of P. americana. Additionally, the Acetylcholinesterase (AchE) and Glutathione-S-transferase (GST) activities of S. litura feeding on P. americana were higher than that of S. litura feeding on artificial diets or P. icosandra. The content of lignin and flavonoids in P. americana was relatively high, whereas starch content was relatively low. These findings suggest invasive plants have higher resistance to herbivores, thereby suffering less damage than exotic noninvasive plants.

Alien Species in the Pioneer and Ruderal Vegetation of Ukraine

Invasions of nonnative plants are widely recognized as one of the major threats to the biodiversity of natural ecosystems on a global scale. Pioneer and ruderal habitats are the primary locations for the penetration of alien plants. Both pioneer and ruderal vegetation are very close in their genesis and beginning of development; therefore, a comparative analysis of their alien components and historical trends would contribute to clarifying the direction of successional changes and the possible management of destructive processes caused by anthropogenic influences in different types of habitats. The results of a structural and comparative analysis of the alien fractions of the coenofloras of the pioneer and ruderal vegetation of Ukraine indicated that the systematic, biomorphological, ecological, and geographical structures of these species show a high similarity, according to many of the main indicators, which allows them to successfully implement a strategy of invasion, particularly in communities characterized by instability and weak coenotic connections. It was established that the ecotopes of both types of vegetation are very favorable to the penetration and establishment of alien species; however, disturbed habitats of the ruderal type are more prone to invasions. In the communities of both pioneer and ruderal vegetation, alien species can become successfully established at the coenotic level, forming phytocoenoses of different hierarchical ranks. The results of this study will contribute to the identification of general patterns of invasions and the optimization (management) of disturbed and unstable natural ecosystems.

Phytochemical profiling and biological activity of the extracts obtained from green biomass of three Miscanthus L. species using supercritical carbon dioxide extraction

Taxa belonging to the genus Miscanthus L. (silvergrass) are non-invasive plants that can grow on marginal land that are not suitable for food production. These species give high yields of lignocellulosic biomass, being a rich and renewable source of organic matter for the production of second-generation biofuels (ethanol) and for other practical purposes, such as raw material for paper production. The most promising species of the genus Miscanthus L., in terms of practical use in industry and agriculture, are M. sinensis, M. sacchariflorum and their hydride - M. × giganteus. In this study, extracts obtained from the green biomass of these Miscanthus L. species underwent detailed phytochemical investigation and multidirectional biological evaluation. The extracts were prepared using supercritical fluid extraction with water as co-solvent. The qualitative RP-HPLC/PDA analysis of the extracts after their purification with solid-phase extraction confirmed their similar phytochemical profiles. Six free phenolic acids ( p -hydroxybenzoic, isovanillic, syringic, p -coumaric, ferulic and isoferulic) and one trans -cinnamic acid derivative were identified and determined. The antimicrobial, antiviral, anthelmintic and anticancer activity of the supercritical extracts of Miscanthus L. species studied was revealed for the first time. Moreover, the extracts possessed low cytotoxicity against normal cells. This screening evaluation showed that, besides giving high yields of lignocellulosic biomass, these grasses could also be a source of valuable bioactive compounds for the pharmaceutical and cosmetic industries. • Supercritical carbon dioxide extracts of silvergrasses had similar phenolic profiles. • All slivergrass extracts showed antibacterial and antifungal activities. • Amur and giant silvergrass extracts revealed anthelmintic (nematocidal) effects. • Chinese and giant silvergrass extracts inhibited herpes simplex virus type-1 cycle. • Amur silvergrass extract was selectively cytotoxic against melanoma cells.

Plastic litter in coastal sand dunes: Degradation behavior and impact on native and non-native invasive plants

Pollution associated to marine plastic litter is raising increasing concerns due to its potential harmful effects on human health, biota, and coastal ecosystems. However, limited information is available on the degradation behavior of plastics, especially biodegradable ones, in dune habitats. Moreover, the effects of plastics on dune plant growth and ability to withstand environmental stresses and invasion by non-native plants have been largely neglected. This is a particularly relevant issue since biological invasions are major threats to dune ecosystems. In this 18-month study, we examined the degradation behavior of two plastic bags, non-biodegradable (NBP) or biodegradable/compostable (BP), in the dune environment by visual observations and analytical techniques. Concomitantly, we investigated the individual and combined effects of bag type and sand burial (no burial vs. partial burial) on the performance of a native dune plant (Thinopyrum junceum) and an invasive plant (Carpobrotus sp.) and on their interaction. NBP did not show relevant degradation signs over the experimental period as expected. BP exhibited gradual surface modifications and changes in chemical functionality and were almost disintegrated after 18 months. Bags and burial reduced independently T. junceum survival and growth, and most plants died within 8 months of plastic exposure. Bags and burial did not affect Carpobrotus survival. However, burial decreased Carpobrotus growth while NBP increased it. Both plastics increased Carpobrotus competitive ability, and no T. junceum plants survived to co-occurrent Carpobrotus, BP, and burial. These findings indicate that removing all littered plastics from beach-dune systems not only is critical to reduce plastic pollution but also to prevent further spread of invasive species in coastal dunes.

Plantifa: Antifascist Guerrilla Gardening Curriculum

This paper suggests that an anti-fascist guerilla gardening (Plantifa) curriculum offers unique educational opportunities in the form of wholesome, and much needed, praxis. Utilizing anti-fascist (Bray, 2017), decolonizing (Tuck et al., 2014), and eco-justice frameworks (Shiva, 2015), Plantifa presents community activism that connects people with place, history, permaculture, and subversion of hegemony. In the context of education, a Plantifa curriculum offers learners to be immersed with their communities and local ecosystems, beyond mere classroom walls. It is a process of mapping local terrain and history, identifying non-invasive plants and suitable locations, considering food-bearing plants for community needs, as well as the afterward tasks of watering and nurturing. Questions of, "Why is 'democracy' as we understand and practice limited to humans, and who, what, or where ought to be included in a democracy?"; “Is planting local flora legally or ethically wrong?” and “Why is anti-fascism important to our community and our eco-system?” are just some of the questions learners can consider during this process of eco-revanchism. Ultimately, we are connecting wholeheartedly with the anti-fascist movement all over the world by appropriating their acronym (Antifa) with deference as a way to plant seeds of love against hierarchies. We are Plantifa!

Variation in plant traits and phylogenetic structure associated with native and nonnative species in an industrialized flora

Industrialized sites are hotspots for nonnative species because of continuous anthropogenic disturbance and nonnative propagule rain resulting from hitchhikers exchanged through global trade. Investigating plant traits and the phylogenetic structure of species at initial ports of entry can contribute to our understanding of how species are introduced to, assembled into, and survive at industrialized sites, which can also inform how susceptible these sites are to nonnative plant invasions. To compare native and nonnative species, we asked three questions: 1) Are plant traits differentially associated with species nativity (native versus nonnative)? (2) Do these traits have phylogenetic signals? and (3) What is the phylogenetic structure of each trait for native and nonnative species? We collected, identified, and vouchered 170 angiosperm species within the Garden City Terminal at the Port of Savannah, Georgia, USA, the largest container terminal in North America. Species nativity was derived from the literature, as were traits of pollination syndrome, dispersal syndrome, duration, and growth habit. Pearson’s Chi-squared tests were used to determine if traits were differentially associated with species nativity. Phylogenetic signal, along with mean pairwise distance (MPD) and mean nearest taxon distance (MNTD), were used to assess the degree of phylogenetic relatedness of native and nonnative species with each trait. Nonnative species showed a significant association with multiple pollination syndromes. Native species were significantly associated with perennial duration and zoophily pollination syndrome. All traits possessed a phylogenetic signal, and the anemophily pollination syndrome was significantly clustered for both native and nonnative species. Still, most other traits differed in their phylogenetic structure pattern based on the nativity. Overall, findings suggest that the environment is filtering for native and nonnative species that possess traits promoting introduction and survival at this industrialized point-of-entry. They also suggest that nonnative species trait differences partition available niches that promote their introduction to the site. More research is needed at industrialized sites to inventory and monitor the floristic community, investigate the establishment and spread probabilities of nonnative species, and prevent and mitigate nonnative species risks and impacts.

Yield-SpikeSegNet: An Extension of SpikeSegNet Deep-Learning Approach for the Yield Estimation in the Wheat Using Visual Images

ABSTRACT High-throughput plant phenotyping integrated with computer vision is an emerging topic in the domain of nondestructive and noninvasive plant breeding. Analysis of the emerging grain spikes and the grain weight or yield estimation in the wheat plant for a huge number of genotypes in a nondestructive way has achieved significant research attention. In this study, we developed a deep learning approach, “Yield-SpikeSegNet,” for the yield estimation in the wheat plant using visual images. Our approach consists of two consecutive modules: “Spike detection module” and “Yield estimation module.” The spike detection module is implemented using a deep encoder-decoder network for spike segmentation and output of this module is spike area and spike count. In yield estimation module, we develop machine learning models using artificial neural network and support vector regression for the yield estimation in the wheat plant. The model’s precision, accuracy, and robustness are found satisfactory in spike segmentation as 0.9982, 0.9987, and 0.9992, respectively. The spike segmentation and yield estimation performance reflect that the Yield-SpikeSegNet approach is a significant step forward in the domain of high-throughput and nondestructive wheat phenotyping.

Remember your roots: Biogeographic properties of plants' native habitats can inform invasive plant risk assessments

AbstractAimReducing the effects of invasive plants is best accomplished by predicting which species will invade and preventing their introduction. To do this, risk assessments rely on a variety of plant traits and biogeographic properties to predict potential invasiveness. However, the relative importance of these traits and properties is unknown. Determining which biogeographic properties contribute the most to predicting invasiveness could improve the accuracy and reduce the time needed to complete future risk assessments. Here, we provide a comprehensive analysis and ranking of the biogeographic properties that best differentiate invasive and noninvasive plant species.LocationConterminous United States.MethodsWe compiled county‐level distributions of 10,721 vascular plant species native to the conterminous United States of which 884 were established elsewhere and 131 were invasive elsewhere. For each species, we used native distribution data to calculate biogeographic properties, including range size, human modification and abiotic niche breadth. We assessed the ability of biogeographic properties to predict whether each species was invasive outside of the United States using random forest classification models.ResultsVariables that represent the breadth of a species' native range, including the ranges of soil textures, ranges of soil fertility and total geographic area, are strong predictors of plant invasiveness. Models that included these variables correctly classified 86% of invasive species and 62% of noninvasive species. Variables representing resource availability and disturbance regime were not useful for distinguishing between established and invasive species.Main conclusionsFocusing on niche breadth properties could improve the accuracy of risk assessments and reduce the effort spent compiling information with lower predictive power. The importance of niche breadth in this analysis supports previous findings that broad physiological tolerance enables survival and reproduction in numerous environments, thereby increasing the likelihood of invasion.