Channel Attention GAN-Based Synthetic Weed Generation for Precise Weed Identification.

Weed is a major biological factor causing declines in crop yield. However, widespread herbicide application and indiscriminate weeding with soil disturbance are of great concern because of their environmental impacts. Site-specific weed management (SSWM) refers to a weed management strategy for digital agriculture that results in low energy loss. Deep learning is crucial for developing SSWM, as it distinguishes crops from weeds and identifies weed species. However, this technique requires substantial annotated data, which necessitates expertise in weed science and agronomy. In this study, we present a channel attention mechanism-driven generative adversarial network (CA-GAN) that can generate realistic synthetic weed data. The performance of the model was evaluated using two datasets: the public segmented Plant Seedling Dataset (sPSD), featuring nine common broadleaf weeds from arable land, and the Institute for Sustainable Agro-ecosystem Services (ISAS) dataset, which includes five common summer weeds in Japan. Consequently, the synthetic dataset generated by the proposed CA-GAN obtained an 82.63% recognition accuracy on the sPSD and 93.46% on the ISAS dataset. The Fréchet inception distance (FID) score test measures the similarity between a synthetic and real dataset, and it has been shown to correlate well with human judgments of the quality of synthetic samples. The synthetic dataset achieved a low FID score (20.95 on the sPSD and 24.31 on the ISAS dataset). Overall, the experimental results demonstrated that the proposed method outperformed previous state-of-the-art GAN models in terms of image quality, diversity, and discriminability, making it a promising approach for synthetic agricultural data generation.

From green to red: Urban heat stress drives leaf color evolution.

Prevalence of impervious surface and resulting higher temperatures in urban areas, known as urban heat islands, comprises prominent characteristics in global cities. However, it is not known whether and how urban plants adapt to such heat stress. This study focused on Oxalis corniculata, which has intraspecific polymorphism in leaf color (green and red) and examined whether the leaf color variation is associated with urban heat stress. Field observations revealed that green-leaved plants were dominant in green habitats, and red-leaved individuals were dominant in urban habitats, at local (<500 meters), landscape (<50 kilometers), and global scales. Growth and photosynthesis experiments demonstrated that red-leaved individuals performed better under heat stress, while green-leaved individuals performed better under nonstressful conditions. Genome-wide SNP analysis suggests that the red leaf may have evolved multiple times from the ancestral green leaf. Overall, the results suggest that the red leaves of O. corniculata observed in cities worldwide are evidence of plant adaptive evolution due to urban heat islands.

Drone-Based Harvest Data Prediction Can Reduce On-Farm Food Loss and Improve Farmer Income.

On-farm food loss (i.e., grade-out vegetables) is a difficult challenge in sustainable agricultural systems. The simplest method to reduce the number of grade-out vegetables is to monitor and predict the size of all individuals in the vegetable field and determine the optimal harvest date with the smallest grade-out number and highest profit, which is not cost-effective by conventional methods. Here, we developed a full pipeline to accurately estimate and predict every broccoli head size (n > 3,000) automatically and nondestructively using drone remote sensing and image analysis. The individual sizes were fed to the temperature-based growth model and predicted the optimal harvesting date. Two years of field experiments revealed that our pipeline successfully estimated and predicted the head size of all broccolis with high accuracy. We also found that a deviation of only 1 to 2 days from the optimal date can considerably increase grade-out and reduce farmer's profits. This is an unequivocal demonstration of the utility of these approaches to economic crop optimization and minimization of food losses.

Evolutionary psychology of entomophobia and its implications for insect conservation.

Many people, especially those living in developed countries, exhibit irrational negative feelings (e.g. fear, disgust, and aversion) toward insects. This so-called 'entomophobia' has often been suggested as a key contributing factor to the ongoing global decline in insects. However, this topic has not been well-investigated. From this point of view, we discuss the formation processes of entomophobia and its consequences from an evolutionary psychological perspective. Adopting the concept of the behavioral immune system, we suggest that the negative responses toward insects exhibited by modern people are driven by a series of emotional, cognitive, and behavioral traits that evolved to avoid infectious diseases. We then provide several strategic recommendations for mitigating the prevalence of entomophobia and a roadmap for better understanding how individual-level entomophobia can influence insect conservation. Understanding the human psychological dimension behind the ongoing decline of insects will provide useful insight on how best to mitigate this decline.

The vicious cycle of biophobia.

People can express irrational fears and disgust responses towards certain wild organisms. This so-called 'biophobia' can be useful and indeed necessary in some circumstances. Biophobia can, however, also lead to excessive distress and anxiety which, in turn, can result in people avoiding interactions with nature. Here, we highlight concern that this reduction in interactions with nature might lead to progressive increases in biophobia, entrenching it more in individuals and across society. We propose the 'vicious cycle of biophobia', a concept that encapsulates how excessive aversion towards nature might emerge and grow in society. The vicious cycle of biophobia risks accelerating the extinction of experience, leading to long-term adverse consequences for the conservation of biodiversity.

Evolution of competitive traits changes species diversity in a natural field.

Studying the interaction between evolutionary and ecological processes (i.e. eco-evolutionary dynamics) has great potential to improve our understanding of biological processes such as species interactions, community assembly and ecosystem functions. However, most experimental studies have been conducted under controlled laboratory or mesocosm conditions, and the importance of these interactions in natural field communities has not been evaluated. In this study, we focused on the contemporary divergence of a competitive trait (the height-width ratio) of an annual grass Eleusine indica between urban and farmland populations and investigated how trait evolution affects ecological processes by transplanting E. indica individuals from lineages with different trait values into semi-natural grassland. The competitive trait of the transplanted individuals not only affected their own growth and fitness, but also affected the vegetative growth of the competing species and the species diversity. These results indicate that the evolution of competitive traits, even in a single species, can influence the community species diversity through changes in interspecific interactions. Eco-evolutionary interactions therefore play a crucial role in natural field environments. Our results suggest that understanding intraspecific variation in competitive traits driven by rapid evolution is essential for understanding interspecific competitive interactions, community assembly and species diversity.

Evolutionary ecology of climacteric and non-climacteric fruits.

Fleshy fruits can be divided between climacteric (CL, showing a typical rise in respiration and ethylene production with ripening after harvest) and non-climacteric (NC, showing no rise). However, despite the importance of the CL/NC traits in horticulture and the fruit industry, the evolutionary significance of the distinction remains untested. In this study, we tested the hypothesis that NC fruits, which ripen only on the plant, are adapted to tree dispersers (feeding in the tree), and CL fruits, which ripen after falling from the plant, are adapted to ground dispersers. A literature review of 276 reports of 80 edible fruits found a strong correlation between CL/NC traits and the type of seed disperser: fruits dispersed by tree dispersers are more likely to be NC, and those dispersed by ground dispersers are more likely to be CL. NC fruits are more likely to have red-black skin and smaller seeds (preferred by birds), and CL fruits to have green-brownish skin and larger seeds (preferred by large mammals). These results suggest that the CL/NC traits have an important but overlooked seed dispersal function, and CL fruits may have an adaptive advantage in reducing ineffective frugivory by tree dispersers by falling before ripening.

GIS-Based Analysis for UAV-Supported Field Experiments Reveals Soybean Traits Associated With Rotational Benefit.

Recent advances in unmanned aerial vehicle (UAV) remote sensing and image analysis provide large amounts of plant canopy data, but there is no method to integrate the large imagery datasets with the much smaller manually collected datasets. A simple geographic information system (GIS)-based analysis for a UAV-supported field study (GAUSS) analytical framework was developed to integrate these datasets. It has three steps: developing a model for predicting sample values from UAV imagery, field gridding and trait value prediction, and statistical testing of predicted values. A field cultivation experiment was conducted to examine the effectiveness of the GAUSS framework, using a soybean-wheat crop rotation as the model system Fourteen soybean cultivars and subsequently a single wheat cultivar were grown in the same field. The crop rotation benefits of the soybeans for wheat yield were examined using GAUSS. Combining manually sampled data (n = 143) and pixel-based UAV imagery indices produced a large amount of high-spatial-resolution predicted wheat yields (n = 8,756). Significant differences were detected among soybean cultivars in their effects on wheat yield, and soybean plant traits were associated with the increases. This is the first reported study that links traits of legume plants with rotational benefits to the subsequent crop. Although some limitations and challenges remain, the GAUSS approach can be applied to many types of field-based plant experimentation, and has potential for extensive use in future studies.

A room with a green view: the importance of nearby nature for mental health during the COVID-19 pandemic.

The COVID-19 pandemic and its global response have resulted in unprecedented and rapid changes to most people's day-to-day lives. To slow the spread of the virus, governments have implemented the practice of physical distancing ("social distancing"), which includes isolation within the home with limited time spent outdoors. During this extraordinary time, nature around the home may play a key role in mitigating against adverse mental health outcomes due to the pandemic and the measures taken to address it. To assess whether this is the case, we conducted an online questionnaire survey (n = 3,000) in Tokyo, Japan, to quantify the association between five mental health outcomes (depression, life satisfaction, subjective happiness, self-esteem, and loneliness) and two measures of nature experiences (frequency of greenspace use and green view through windows from home). Accounting for sociodemographic and lifestyle variables, we found that the frequency of greenspace use and the existence of green window views from within the home was associated with increased levels of self-esteem, life satisfaction, and subjective happiness and decreased levels of depression, anxiety, and loneliness. Our findings suggest that a regular dose of nature can contribute to the improvement of a wide range of mental health outcomes. With the recent escalation in the prevalence of mental health disorders, and the possible negative impacts of the COVID-19 pandemic on public mental health, our findings have major implications for policy, suggesting that urban nature has great potential to be used as a "nature-based solution" for improved public health.

Field-based individual plant phenotyping of herbaceous species by unmanned aerial vehicle.

Recent advances in Unmanned Aerial Vehicle (UAVs) and image processing have made high-throughput field phenotyping possible at plot/canopy level in the mass grown experiment. Such techniques are now expected to be used for individual level phenotyping in the single grown experiment.We found two main challenges of phenotyping individual plants in the single grown experiment: plant segmentation from weedy backgrounds and the estimation of complex traits that are difficult to measure manually.In this study, we proposed a methodological framework for field-based individual plant phenotyping by UAV. Two contributions, which are weed elimination for individual plant segmentation, and complex traits (volume and outline) extraction, have been developed. The framework demonstrated its utility in the phenotyping of Helianthus tuberosus (Jerusalem artichoke), an herbaceous perennial plant species.The proposed framework can be applied to either small and large scale phenotyping experiments.

Zoos and animated animals increase public interest in and support for threatened animals.

Raising public interest in and conservation activity for threatened species is critically important for successful biodiversity conservation. However, our understanding of what influences the public interest in threatened animals and how the interest induces conservation activities is quite limited. Here, we examined the role of zoos and a television program featuring animated animals in shaping public interest in and support for animals including threatened species from 2011 to 2018 in Japan. Public interest was measured by Internet search volumes and support by donation activity in zoos. Results showed that both zoos and the animated program made a significant contribution to increasing public interest in animals. The spatial distribution of the Google search volume for 92 animals was correlated with that of animals exhibited in zoos. In tandem with this, the broadcast of a Japanese animated TV program featuring animals (Kemono Friends) increased the Google search volume and Wikipedia pageviews for animal species featured in the program. The total increases of search volume and Wikipedia pageviews were estimated to be approximately 4.66 million for 37 species and 1.06 million for 63 species, respectively. Furthermore, after the original broadcasts of the program, we found that animals featured in the animated program had more financial supporters through donations than animals that were not featured. These results are striking because they indicate the increase in public interest led to actual conservation activity by citizens. Overall, our results demonstrate that both zoos and the animated TV program played important roles in promoting public interest in and support for threatened animals. Enhanced collaborations between people in the entertainment industry and conservation entities could contribute greatly to global biodiversity conservation.

Effect of paternal age on the birth sex ratio in captive populations of aye-aye (Daubentonia madagascariensis (Gmelin)).

For the management of captive populations of zoo animals, it is important to elucidate factors that affect the offspring birth sex ratio. On the basis of the sex allocation theory, the Trivers-Willard and mate attractive/quality hypotheses predict that maternal and paternal conditions affect offspring birth sex ratios. We examined these predictions for the birth sex ratio of aye-aye Daubentonia madagascariensis (Gmelin) by analyzing the pedigree information in the International Studbook. We found that the birth sex ratio of the aye-aye was affected by the paternal age, but not maternal age and other environmental factors (birth year, season, and institution). The younger the sire, the more the offspring sex ratio was biased toward males. These results are useful for the effective population management of captive aye-aye and illustrated the usefulness of the sex allocation theory in the sex ratio management of zoo animals.

Genotype-aggregated planting improves yield in Jerusalem artichoke (Helianthus tuberosus) due to self/non-self-discrimination.

Accumulating evidence indicates that plants are capable of self/non-self and kin/stranger discrimination. Plants increase biomass of and resource allocation to roots when they encounter roots of conspecific non-self-neighbors, but not when they encounter self roots. Root proliferation usually occurs at the expense of reproductive investment. Therefore, if clonal crops are capable of self/non-self-discrimination, spatially aggregated planting with seedlings of the same genotype may decrease root proliferation and produce a higher yield than planting without considering seedling genotype. To test this idea, we grew Helianthus tuberosus (Jerusalem artichoke) in pot and field conditions and examined self/non-self-discrimination and the effectiveness of genotype-aggregated planting. Plants grown in self pairs allocated less to root biomass than plants grown in non-self pairs in both pot and field conditions; in field conditions, the self pairs produced 40% more tubers by weight than the non-self pairs. When six sprouts from seed tuber of two different genotypes were grown together, with the two genotypes planted aggregately (AGG) or alternately (ALT), plants in the AGG group produced 14% more tubers than plants in the ALT group. These results suggest that spatial aggregation of genotypes increases tuber production in H. tuberosus. Because we found no evidence for trade-offs between root biomass and tuber production, suppression of root proliferation may not be the only mechanism behind the benefits of genotype aggregation. By applying the concept of self/non-self-discrimination, farmers can increase crop production without additional external inputs or expansion of agricultural land use.

Self-discrimination in vine tendrils of different plant families.

Previous study reported a novel type of self-discrimination in the tendrils of the vine Cayratia japonica (Vitaceae). However, whether self-discrimination in tendrils is common in vine plant species has not been elucidated. Here, we investigated whether tendrils of Momordica charantia var. pavel (Cucurbitaceae), Cucumis sativus (Cucurbitaceae) and Passiflora caerulea (Passifloraceae) can discriminate self and non-self plants. We also investigated whether the tendrils of M. charantia and C. sativus can discriminate differences in cultivars to determine the discrimination ability for genetic similarity. We found that tendrils of the M. charantia and P. caerulea were more likely to coil around non-self plant than self plants, but not in C. sativus. Our findings support the common occurrence of self-discrimination in tendrils in different plant taxa, although some species lacked it. Furthermore, tendrils of M. charantia more rapidly coil around different cultivars than around same cultivars. The tendrils of M. charantia may can discriminate differences in cultivars.

Size advantage for male function and size-dependent sex allocation in Ambrosia artemisiifolia, a wind-pollinated plant.

In wind-pollinated plants, male-biased sex allocation is often positively associated with plant size and height. However, effects of size (biomass or reproductive investment) and height were not separated in most previous studies. Here, using experimental populations of monoecious plants, Ambrosia altemisiifolia, we examined (1) how male and female reproductive investments (MRI and FRI) change with biomass and height, (2) how MRI and height affect male reproductive success (MRS) and pollen dispersal, and (3) how height affects seed production. Pollen dispersal kernel and selection gradients on MRS were estimated by 2,102 seeds using six microsatellite markers. First, MRI increased with height, but FRI did not, suggesting that sex allocation is more male-biased with increasing plant height. On the other hand, both MRI and FRI increased with biomass but often more greatly for FRI, and consequently, sex allocation was often female-biased with biomass. Second, MRS increased with both height and MRI, the latter having the same or larger effect on MRS. Estimated pollen dispersal kernel was fat-tailed, with the maximum distance between mates tending to increase with MRI but not with height. Third, the number of seeds did not increase with height. Those findings showed that the male-biased sex allocation in taller plants of A. artemisiifolia is explained by a direct effect of height on MRS.

Vine tendrils use contact chemoreception to avoid conspecific leaves.

Movement and growth habit of climbing plants have attracted attention since the time of Charles Darwin; however, there are no reports on whether plants can choose suitable hosts or avoid unsuitable ones based on chemoreception. Here, I show that the tendrils of Cayratia japonica (Vitaceae) appear to avoid conspecific leaves using contact chemoreception for oxalates, which are highly concentrated in C. japonica leaves. The coiling experiments show that C. japonica has a flexible plastic response to avoid coiling around conspecific leaves. The coiling response is negatively correlated with the oxalate content in the contacted leaves. Experiments using laboratory chemicals indicate that the tendrils avoid oxalate-coated plastic sticks. These results indicate that the tendrils of C. japonica avoid coiling around a conspecific leaf based on contact chemoreception for oxalate compounds. The tendrils of climbing plants may function as a chemoreceptor system to detect the chemical cues of a contacted plant.

Understanding and monitoring the consequences of human impacts on intraspecific variation.

Intraspecific variation is a major component of biodiversity, yet it has received relatively little attention from governmental and nongovernmental organizations, especially with regard to conservation plans and the management of wild species. This omission is ill-advised because phenotypic and genetic variations within and among populations can have dramatic effects on ecological and evolutionary processes, including responses to environmental change, the maintenance of species diversity, and ecological stability and resilience. At the same time, environmental changes associated with many human activities, such as land use and climate change, have dramatic and often negative impacts on intraspecific variation. We argue for the need for local, regional, and global programs to monitor intraspecific genetic variation. We suggest that such monitoring should include two main strategies: (i) intensive monitoring of multiple types of genetic variation in selected species and (ii) broad-brush modeling for representative species for predicting changes in variation as a function of changes in population size and range extent. Overall, we call for collaborative efforts to initiate the urgently needed monitoring of intraspecific variation.

Flower-Visiting Butterflies Avoid Predatory Stimuli and Larger Resident Butterflies: Testing in a Butterfly Pavilion.

The flower-visiting behaviors of pollinator species are affected not only by flower traits but also by cues of predators and resident pollinators. There is extensive research into the effects of predator cues and resident pollinators on the flower-visiting behaviors of bee pollinators. However, there is relatively little research into their effects on butterfly pollinators probably because of the difficulty in observing a large number of butterfly pollination events. We conducted a dual choice experiment using artificial flowers under semi-natural conditions in the butterfly pavilion at Tama Zoological Park to examine the effects of the presence of a dead mantis and resident butterflies have on the flower-visiting behavior of several butterfly species. From 173 hours of recorded video, we observed 3235 visitations by 16 butterfly species. Statistical analysis showed that (1) butterflies avoided visiting flowers occupied by a dead mantis, (2) butterflies avoided resident butterflies that were larger than the visitor, and (3) butterflies showed greater avoidance of a predator when the predator was present together with the resident butterfly than when the predator was located on the opposite flower of the resident. Finally, we discuss the similarities and differences in behavioral responses of butterfly pollinators and bees.

Self-discrimination in the tendrils of the vine Cayratia japonica is mediated by physiological connection.

Although self-discrimination has been well documented, especially in animals, self-discrimination in plants has been identified in only a few cases, such as self-incompatibility in flowers and root discrimination. Here, were port a new form of self-discrimination in plants: discrimination by vine tendrils. We found that tendrils of the perennial vine Cayratia japonica were more likely to coil around neighbouring non-self plants than neighbouring self plants in both experimental and natural settings. The higher level of coiling around a physiologically severed self plant compared with that around a physiologically connected self plant suggested that self-discrimination was mediated by physiological coordination between the tendril and the touched plant as reported for self-discrimination in roots. The results highlight the importance of self-discrimination for plant competition not only underground,but also above-ground.

Changes in defense of an alien plant Ambrosia artemisiifolia before and after the invasion of a native specialist enemy Ophraella communa.

The evolution of increased competitive ability hypothesis (EICA) predicts that when alien plants are free from their natural enemies they evolve lower allocation to defense in order to achieve a higher growth rate. If this hypothesis is true, the converse implication would be that the defense against herbivory could be restored if a natural enemy also becomes present in the introduced range. We tested this scenario in the case of Ambrosia artemisiifolia (common ragweed) - a species that invaded Japan from North America. We collected seeds from five North American populations, three populations in enemy free areas of Japan and four populations in Japan where the specialist herbivore Ophraella communa naturalized recently. Using plants grown in a common garden in Japan, we compared performance of O. communa with a bioassay experiment. Consistent with the EICA hypothesis, invasive Japanese populations of A. artemisiifolia exhibited a weakened defense against the specialist herbivores and higher growth rate than native populations. Conversely, in locations where the herbivore O. communa appeared during the past decade, populations of A. artemisiifolia exhibited stronger defensive capabilities. These results strengthen the case for EICA and suggest that defense levels of alien populations can be recuperated rapidly after the native specialist becomes present in the introduced range. Our study implies that the plant defense is evolutionary labile depending on plant-herbivore interactions.