Ecological Focus Research Articles

Pathwalker: A New Individual-Based Movement Model for Conservation Science and Connectivity Modelling

Understanding organism movement is at the heart of many ecological disciplines. The study of landscape connectivity—the extent to which a landscape facilitates organism movement—has grown to become a central focus of spatial ecology and conservation science. Several computational algorithms have been developed to model connectivity; however, the major models in use today are limited by their lack of flexibility and simplistic assumptions of movement behaviour. In this paper, we introduce a new spatially-explicit, individual- and process-based model called Pathwalker, which simulates organism movement and connectivity through heterogeneous landscapes as a function of landscape resistance, the energetic cost of movement, mortality risk, autocorrelation, and directional bias towards a destination, all at multiple spatial scales. We describe the model’s structure and parameters and present statistical evaluations to demonstrate the influence of these parameters on the resulting movement patterns. Written in Python 3, Pathwalker works for any version of Python 3 and is freely available to download online. Pathwalker models movement and connectivity with greater flexibility compared with the dominant connectivity algorithms currently available in conservation science, thereby, enabling more detailed predictions for conservation practice and management. Moreover, Pathwalker provides a highly capable simulation framework for exploring theoretical and methodological questions that cannot be addressed with empirical data alone.

Among-Species Differences in Seasonal Timing and Weather Correlates of Autumn Raptor Migration at Khao Dinsor, Thailand, 2015–2016

ABSTRACT Identifying the drivers of shifts in the abundance of wildlife species has been a central focus of conservation ecology recently. With growing concern about the impacts of global environmental change on biodiversity patterns, ecologists are challenged to better understand the relationships between species' abundance and various environmental factors. Using raptor count data collected following a standardized protocol at Khao Dinsor, southern Thailand, in 2015 and 2016, we characterized the seasonal timing and identified weather associations of the visible migration of representative species, namely the Black Baza (Aviceda leuphotes), Chinese Sparrowhawk (Accipiter soloensis), and Oriental Honey-Buzzard (Pernis ptilorhynchus). We explored the associations of their daily total counts with local weather variables. We found that the magnitude of their migration within the season was linked with the prevailing meteorological conditions. In general, daily counts of all three species were positively associated with predominant wind patterns. Air temperature was positively associated with the daily counts of species that migrated early in the season (Chinese Sparrowhawk and Oriental Honey-Buzzard). Barometric pressure was negatively associated with the daily counts of species whose migration window coincides with the shift in monsoon season (Black Baza and Oriental Honey-Buzzard). These results provide us with a better understanding of the drivers of migration patterns at a representative monitoring site on a globally important and heavily used flyway. They may be useful for making better inferences and predictions on the population trajectories of migrating raptors in future environmental change scenarios.

Higher tree diversity is linked to higher tree mortality

Examining the relationship between tree diversity and ecosystem functioning has been a recent focus of forest ecology. Particular emphasis has been given to the impact of tree diversity on productivity and to its potential to mitigate negative global change effects; however, little attention has been paid to tree mortality. This is critical because both tree mortality and productivity underpin forest ecosystem dynamics and therefore forest carbon sequestration. Neglecting tree mortality leaves a large part of the picture undocumented. Here we show that increasingly diverse forest stands have increasingly high mortality probabilities. We found that the most species-rich stands in temperate biomes had mortality probabilities more than sevenfold higher than monospecific stands (∼0.6% year−1 in monospecific stands to 4.0% year−1 in the most species-rich stands) while in boreal stands increases were less pronounced but still significant (∼1.1% year−1 in monospecific stands to 1.8% year−1 in the most species-rich stands). Tree species richness was the third-most-important predictor of mortality in our models in temperate forests and the fifth-most-important predictor in boreal forests. Our results highlight that while the promotion of tree diversity undoubtedly has many positive effects on ecosystem functioning and the services that trees provide to humanity, it remains important to consider all aspects of forest dynamics in order to properly predict the implications of maintaining and promoting tree diversity.

Bacterial lipopolysaccharide induces settlement and metamorphosis in a marine larva

How larvae of the many phyla of marine invertebrates find places appropriate for settlement, metamorphosis, growth, and reproduction is an enduring question in marine science. Biofilm-induced metamorphosis has been observed in marine invertebrate larvae from nearly every major marine phylum. Despite the widespread nature of this phenomenon, the mechanism of induction remains poorly understood. The serpulid polychaete Hydroides elegans is a well established model for investigating bacteria-induced larval development. A broad range of biofilm bacterial species elicit larval metamorphosis in H. elegans via at least two mechanisms, including outer membrane vesicles (OMVs) and complexes of phage-tail bacteriocins. We investigated the interaction between larvae of H. elegans and the inductive bacterium Cellulophaga lytica, which produces an abundance of OMVs but not phage-tail bacteriocins. We asked whether the OMVs of C. lytica induce larval settlement due to cell membrane components or through delivery of specific cargo. Employing a biochemical structure–function approach with a strong ecological focus, the cells and OMVs produced by C. lytica were interrogated to determine the class of the inductive compounds. Here, we report that larvae of H. elegans are induced to metamorphose by lipopolysaccharide produced by C. lytica. The widespread prevalence of lipopolysaccharide and its associated taxonomic and structural variability suggest it may be a broadly employed cue for bacterially induced larval settlement of marine invertebrates.

Improving insect conservation values of agri-environment schemes through diversified seed mixtures

To counteract ongoing biodiversity declines, many European countries have implemented agri-environment schemes (AES) such as ecological focus areas (EFAs), the efficiency of which is often questioned due to low levels of habitat quality. We established new grasslands (NG) using a more diverse seed mixture specifically adapted to mimic low-intensity meadows occurring in our study region in Lower Austria. We compared abundance, species richness, species assemblages and β diversity of solitary bees, bumblebees, syrphids, butterflies, orthopterans, true bugs and cicadas in currently subsidized legume-grass mixtures targeted at supporting pollinators (SG), old grasslands (OG) and NG over a two-year period. Bees, bumblebees and syrphids clearly profited from NG in terms of abundance and species richness, while SG were significantly less attractive. Butterflies were most abundant in OG and significantly less attracted to both SG and NG. True bugs were particularly attracted to NG and SG. However, we did not find any preference in cicadas. Orthopteran species richness was similar in all three types, but individual numbers were significantly lower in NG than in OG. OG and NG supported highly distinctive species assemblages. For solitary bees, syrphids, true bugs and cicadas distinctiveness of sites (β diversity) was more decisive for overall diversity than local diversity. We urge policy makers to put more effort into the establishment of EFAs by using high quality seed mixtures of regionally adapted species and increased plant diversity. Furthermore, preserving permanent grasslands, which support different sets of insect assemblages, should be focused as well to maximize biological conservation value.

Farmland use data and remote sensing for ex-post assessment of CAP environmental performances: An application to soil quality dynamics in Lombardy

With the reform of the European Common Agricultural Policy (CAP) in 2013, subsidies to farms are now bound to the fulfilment of environmentally friendly measures, such as crop diversification and allocation of a share of their farmland to Ecological Focus Areas, the so-called “Greening requirements”. Research on the effects of these policy changes so far have focused mainly on land use transition; however, a detailed investigation of how CAP greening affects the properties of agricultural land is required to assess the actual environmental benefits of the reform. In this study, we present a first attempt to assess the impacts of CAP greening on selected soil quality indices in Lombardy, a populated region in northern Italy where high-intensity agriculture is widespread. We combine high resolution (10/30 m) soil indices from remote sensing based on Landsat-8 and Sentinel-2 data with a regional administrative database covering all agricultural parcels of the region. We then perform a correlation analysis to investigate whether and to what extent greening prescriptions affect the soil quality indices from 2014, representing pre-greening conditions, to 2017, representing greening conditions after 3 years of implementation. Our analysis indicates a high persistence of soil quality indicators and suggests that some crops might have a significant impact on soil quality dynamics, along with farm’s compliance with CAP greening. Although we identified some uncertainties in the soil indices, by integrating a large volume of data and an efficient processing algorithm our method paves the way for ex-post environmental performance assessment of agricultural policies.

Mechanisms of dietary resource partitioning in large‐herbivore assemblages: A plant‐trait‐based approach

Abstract Sympatric large mammalian herbivore species differ in diet composition, both by eating different parts of the same plant and by eating different plant species. Various theories proposed to explain these differences are not mutually exclusive, but are difficult to reconcile and confront with data. Moreover, whereas several of these ideas were originally developed with reference to within‐plant partitioning (i.e. consumption of different tissues), they may analogously apply to partitioning of plant species; this possibility has received little attention. Plant functional traits provide a novel window into herbivore diets and a means of testing multiple hypotheses in a unified framework. We used DNA metabarcoding to characterize the diets of 14 sympatric large‐herbivore species in an African savanna and analysed diet composition in light of 27 functional traits that we measured locally for 204 plant species. Plant traits associated with the deep phylogenetic split between grasses and eudicots formed the primary axis of resource partitioning, affirming the generality and importance of the grazer–browser spectrum. A secondary axis comprised plant traits relevant to herbivore body size. Plant taxa in the diets of large‐bodied species were lower on average in digestible energy and protein, taller on average (especially among grazers), and tended to be higher in tensile strength, zinc, stem‐specific density, and potassium (and lower in sodium, stem dry matter content, and copper). These results are consistent with longstanding hypotheses linking body size with forage quality and height, yet they also suggest the existence of undiscovered links between herbivore body size and a set of rarely considered food–plant traits. We also tested the novel hypothesis that the leaf economic spectrum (LES), a major focus in plant ecology, is an axis of resource partitioning in large‐herbivore assemblages; we found that the LES was a minor axis of individual variation within a few species, but had little effect on interspecific dietary differentiation. Synthesis. These results identify key plant traits that underpin the partitioning of food–plant species in large‐herbivore communities and suggest that accounting for multiple plant traits (and trade‐offs among them) will enable a deeper understanding of herbivore–plant interaction networks.

Identifying cryptic fern gametophytes using DNA barcoding: A review.

Ferns and lycophytes are unique among land plants in having sporophyte (diploid) and gametophyte (haploid) generations that can grow independently of each other. While most studies of fern ecology focus on the more visible sporophytic stage, the gametophyte is critically important, as it is the sexual phase of the life cycle. Yet, fern gametophytes have long been neglected in field studies due to their small size and cryptic morphology. DNA barcoding is a powerful method that can be used to identify field‐collected gametophytes to species and allow for detailed study of their ecology. Here, we review the state of DNA barcoding as applied to fern gametophytes. First, we trace the history of DNA barcoding and how it has come to be applied to fern gametophytes. Next, we summarize case studies that show how DNA barcoding has been used to better understand fern species distributions, gametophyte ecology, and community ecology. Finally, we propose avenues for future research using this powerful tool, including next‐generation DNA sequencing for in‐field identification of cryptic gametophytes.

A predictive model and a field study on heterogeneous slug distribution in arable fields arising from density dependent movement

Factors and processes determining heterogeneous (‘patchy’) population distributions in natural environments have long been a major focus in ecology. Existing theoretical approaches proved to be successful in explaining vegetation patterns. In the case of animal populations, existing theories are at most conceptual: they may suggest a qualitative explanation but largely fail to explain patchiness quantitatively. We aim to bridge this knowledge gap. We present a new mechanism of self-organized formation of a patchy spatial population distribution. A factor that was under-appreciated by pattern formation theories is animal sociability, which may result in density dependent movement behaviour. Our approach was inspired by a recent project on movement and distribution of slugs in arable fields. The project discovered a strongly heterogeneous slug distribution and a specific density dependent individual movement. In this paper, we bring these two findings together. We develop a model of density dependent animal movement to account for the switch in the movement behaviour when the local population density exceeds a certain threshold. The model is fully parameterized using the field data. We then show that the model produces spatial patterns with properties closely resembling those observed in the field, in particular to exhibit similar values of the aggregation index.

Mapping Ecological Focus Areas within the EU CAP Controls Framework by Copernicus Sentinel-2 Data

Greening is a Common Agricultural Policy (CAP) subsidy that ensures that all EU farmers receiving income support produce climate and environmental benefits as part of their farming activities. To receive greening support, it is mandatory for the farmer to carry out three agricultural practices that are considered environmentally and climate friendly: (a) crop diversification; (b) maintenance of permanent meadows and pastures; and (c) presence of an Ecological Focus Area (EFA). Contributions are delivered and monitored by paying agencies (PP) that ordinarily perform administrative checks and spot checks. The latter are provided through photo-interpretation of high-resolution satellite or aerial images and, in specific cases, through local ground checks (GC) as well. In this work, stimulated by the Piemonte Regional Agency for Payments in Agriculture (ARPEA), a prototype service to support PPs’ controls within the greening CAP framework was proposed with special concern for EFA detection. The proposed approach is expected to represent a valid alternative or supporting tool for GC. It relies on the analysis of NDVI time series derived from Copernicus Sentinel-2 data. The study was conducted in the provinces of Turin, Asti and Vercelli within the Piedmont Region (NW Italy), and over 12,500 EFA fields were assessed. Since the recent National Report No. 5465 stipulates that mowing and any other soil management operation is prohibited on set-aside land designated as an EFA during the reference period (RP) between 1st March and 30th June, a time series (TS) of NDVI in the same period was generated. Once averaged at plot level, NDVI trends were modelled by a first-order polynomial, and the correspondent statistics (namely, R2, MAE and maximum residual) was computed. These were assumed to play the role of discriminants in EFA detection based on a thresholding approach (Otsu’s method), calibrated with reference to the training dataset. The threshold satisfaction was therefore tested, and, depending on the number of satisfied thresholds out of the possible three, EFA and non-EFA plots were detected with a different degree of reliability. The correspondent EFA map was generated for the area of interest and validated according to GCs as provided by the ARPEA. The results showed an overall accuracy of 84%, indicating that the approach is promising. The authors retain that this procedure represents a valid alternative (or integrating) tool for ground controls by PPs.

Increased survival rate of Quercus aliena var. Acuteserrata seedlings via nitrogen addition for the succession of pine and pine-oak mixed forests to oak forest

Forest regeneration mechanisms of Pinus tabulaeformis, Pinus armandii, and Quercus aliena var. acuteserrata as the constructive species have been the focus of ecologists and silviculturists, and research to better understand the future of forest community composition, succession patterns, and other aspects of far-reaching influence. However, the influence of nitrogen deposition on the regeneration of different succession stages needs further investigation. In this study, seedlings of the three species of different ages were planted in the pine, pine-oak mixed, and oak forests, and the seedlings which planted by the pot culture with natural soil or fertilization soil, were monitored for two years. Survival and growth indicators, chlorophyll content, and foliar nutritional status of the seedlings were measured. The survival rate and chlorophyll content of P. tabulaeformis, P. armandii, and Q. aliena var. acuteserrata seedlings were the lowest in the oak forest, which might be related to the availability of light in the undergrowth at different stages of succession. Regardless of the forest type, after nitrogen addition, the survival rates of P. tabulaeformis and Q. aliena var. acuteserrata seedlings were the highest for 4-year-old seedlings, and the survival rate of P. armandii seedlings was the highest for 10-year-old ones. Nitrogen addition had no significant effect on the survival rate of P. tabulaeformis and P. armandii seedlings, but changed the nutrient content in their leaves. However, the addition of nitrogen improved the survival rate of Q. aliena var. acuteserrata seedlings, and their competitiveness. Therefore, it can be inferred that nitrogen deposition may promote the succession of P. tabulaeformis forest- to oak forest-in the Qinling Mountains, China.

Analysis on prevalence and epidemic risk of animal plague in different ecological plague foci in Inner Mongolia Autonomous Region

The risk of plague epidemics and relapse of various types of plague foci persists in Inner Mongolia Autonomous Region. For Marmota sibirica plague foci, the animal plague has not been found but antibody has been detected positive. Nowadays, Marmota sibirica has been increasing in population and distribution in China. In bordering countries Mongolia and Russia, the animal plague has been continuously prevalent. For Spermophilus dauricus plague foci, the animal plague has been taken place now and then. Compared to the above foci, the animal plague is most prevalent in Meriones unguiculatus plague foci and frequently spread to humans. Due to higher strain virulence and historical disaster in Marmota sibirica plague foci and Spermophilus dauricus plague foci, plague prevention and control should be strengthened on these foci. In addition to routine surveillance, epidemic dynamics need to be further monitored in these two foci, in order to prevent their relapse and spread to humans.

弃管杉木林杉木数量与群落物种多样性间的关系

森林群落物种多样性格局和动态一直是生态学的研究热点，人工林弃管后演替进程中物种多样性变化也很值得研究。杉木（Cunninghamia lanceolata）作为我国南方林区人工栽培最广、经济价值最高的用材树种之一，其人工林分布面积很大，通常群落结构简单、物种多样性低，然而群落中杉木数量如何影响植物物种多样性，迄今缺乏研究。在浙江省自然保护区内，选择不同疏伐强度和弃管时间的杉木人工林，建立了6个1 hm²长期动态监测样地，在10 m×10 m、20 m×20 m、50 m×50 m和100 m×100 m尺度下，探究群落物种多样性（物种丰富度、Simpson指数、Shannon-Wiener指数和Pielou均匀度指数）的变化规律，分析杉木数量（多度和相对多度）对物种多样性的影响。结果显示：弃管前对杉木林的疏伐强度越高，演替恢复后的群落物种多样性越高。相同疏伐程度下，物种多样性随演替时间的延长有先升高后降低的趋势。取样尺度小于100 m×100 m时，杉木数量与物种多样性呈极显著负相关；100 m×100 m尺度下仅杉木相对多度与3种多样性指数呈显著负相关，杉木多度与各物种多样性均无显著相关性。群落中杉木相对多度在30%以内时，通常拥有较高的物种多样性。;The pattern and dynamics of forest community species diversity have always been the research focus of ecology, and the change of species diversity in the succession process of abandoned plantations is also worth studying. The Chinese fir (Cunninghamia lanceolata) is one of the most widely cultivated woods with the highest economic value in the southern forest region of China. This plantation usually has a simple community structure, low species diversity, and poor stress resistance. As for the community in subtropical area, many scholars have studied and discussed the community characteristics of the Chinese fir forests in different forest ages or different thinning intensities, but how the number of the Chinese fir in the community affects the plant species diversity is lack of research so far. In this study, 6 one-hectare long-term dynamic monitoring plots were established at the abandoned Chinese fir forest with different thinning intensities and abandoned time in four nature reserves of Zhejiang Province. Each woody plant with DBH (diameter at breast height) ≥ 1 cm was investigated, and the species name, DBH, height and coordinates were recorded. The community species diversity (species richness, Simpson index, Shannon-Wiener index and Pielou's evenness index) was investigated at the scales of 10 m×10 m, 20 m×20 m, 50 m×50 m, and 100 m×100 m. The distribution pattern and correlation between the number (abundance and relative abundance) of the Chinese fir and species diversity were analyzed. The results showed that the higher the thinning intensity of the Chinese fir forest before abandonment, the higher the species diversity of the community after succession. Under the same thinning intensity, the species diversity firstly increased and then decreased during succession. When the sampling scale was less than 100 m×100 m, the number of the Chinese fir was negatively correlated with species diversity. Under the scale of 100 m×100 m, only the relative abundance of the Chinese fir was negatively correlated with the three diversity indices (Simpson index, Shannon-Wiener index and Pielou's evenness index), but there was no significant correlation between the abundance of the Chinese fir and species richness. The values of the three diversity indices in each community were consistent, but had no correlation with species richness. In a word, when the relative abundance of the Chinese fir was less than 30%, the community usually had relatively high species diversity.

Editorial 2022

Editorial 2022

Competition of insect decomposers over large vertebrate carrion: Necrodes beetles (Silphidae) vs. blow flies (Calliphoridae).

Large carrion is inhabited by highly variable and interactive communities of insects. Positive interactions in carrion insect communities have been recently the focus in carrion ecology. In contrast, competition between carrion insects is rather undervalued. Here we provide evidence that blow flies (Calliphoridae) and Necrodes beetles (Silphidae), dominant decomposers of large carcasses in terrestrial habitats, compete over carrion. By reanalyzing the results from 90 pig carcasses, we demonstrated that the contribution of the flies and the beetles to the decay was negatively related. The greater part of the large carrion pool was monopolized by blow flies, whereas Necrodes beetles abundantly colonized carcasses, on which blow flies were less effective as decomposers. In behavioral assays, we found that adult beetles killed 4 times more frequently feeding than postfeeding third instar larvae of the flies, with the large decrease in the killing frequency after the larvae reached the age of early third instar. Therefore, adult Necrodes beetles preferentially killed the larvae that were before or in their peak feeding. The study provides evidence that the interaction between blow flies and Necrodes beetles is a combination of indirect exploitative effects of the flies and direct interference effects of the beetles (the mixed competition).

Engineering Resilience to Water Stress in the Late Prehispanic North-Central Andean Highlands (~600–1200 BP)

The Andes are defined by human struggles to provide for, and control, water. Nowhere is this challenge more apparent than in the unglaciated western mountain range Cordillera Negra of the Andes where rain runoff provides the only natural source of water for herding and farming economies. Based on over 20 years of systematic field surveys and taking a political ecology and resilience theory focus, this article evaluates how the Prehispanic North-Central highlands Huaylas ethnic group transformed the landscape of the Andes through the largescale construction of complex hydraulic engineering works in the Cordillera Negra of the Ancash Province, North-Central Peru. It is likely that construction of these engineered landscapes commenced during the Middle Horizon (AD 600–1000), reaching their apogee under the Late Intermediate Period (Huaylas group, AD 1000–1450) and Inca (AD 1450–1532) period, before falling into disuse during the early Spanish colony (AD 1532–1615) through a combination of disease, depopulation, and disruption. Persistent water stress in the western Pacific-facing Andean cordillera was ameliorated through the construction of interlinked dams and reservoirs controlling the water, soil, and wetlands. The modern study of these systems provides useful case-studies for infrastructure rehabilitation potentially providing low-cost, though technologically complex, solutions to modern water security.

Effects of wildflower strips, landscape structure and agricultural practices on wild bee assemblages – A matter of data resolution and spatial scale?

Agricultural systems in Central Europe were redesigned during the last century to attain maximum yields. The results often lead to homogeneous landscapes with only few structures of ecological value and have concurrently exacerbated habitat fragmentation. Perennial wildflower strips have become a significant agri-environmental measure (AEM) to counteract the ecological consequences for wild bees and other pollinators in agricultural landscapes. The effectiveness of AEMs depends on the landscape context, but information about geodata sources and spatial scales relevant for the analysis of landscape effects on wild bees is lacking. This study uses data from various sources on land cover and agricultural practices to assess their applicability in an evaluation of perennial wildflower strips as AEM for wild bees in Saxony-Anhalt, Germany. We investigated the relationships of wild bee species diversity and abundance to the landscape context at spatial scales from 200 m to 10 km considering several factors: land cover/land use, protected areas, crop types, agri-environment schemes/greening, intensity of agriculture, and intensity of grassland farming. In general, our results revealed that landscape effects were more relevant for solitary than social wild bees on flower strips, pointing to a higher limitation of solitary wild bees in nesting resources as compared to social wild bees. Numbers of wild bee species and individuals benefitted from bare soil and ecological focus areas in the surroundings up to 3 km distance, whereas the share of Red List solitary bee species was positively influenced by a variety of factors (e.g., wood structures and grasslands) especially at large scales up to 10 km. The comparison of models based on different land cover data sources showed that the lack of geodata resolution can mask landscape effects on wild bees. Altogether, our results suggest a high potential of data from the Basic Digital Landscape Model (DLM), together with the Integrated Administration and Control System (IACS), to indicate effects of landscape structures and agricultural practices on the species composition and distribution of wild bee assemblages in Germany.

Reconsidering the Price equation: a new partitioning based on species abundances and trait expression

Understanding the causes of the generally positive relationship between biodiversity and ecosystem function (BEF) is a major research focus in ecology. Early analyses of BEF used a modification of the evolutionary Price equation to partition effects of biodiversity into components of complementarity (species richness) and dominance (species composition). However, early experiments and data on BEF did not use information on species traits or relative abundances. Here we extend the Price partition of the total expression of a single trait (such as leaf area) between two communities into five additive components: 1) species richness; 2) average species trait expression; 3) relative abundance; 4) the combined effects of relative abundance and trait expression; 5) absolute abundance. When applied to presence–absence data with no trait variation, the method yields a result that is identical to the original Price partition into two components of complementarity and dominance. When applied to an analysis of relative abundance itself as a trait, our method quantifies the strength of species co‐occurrences as a difference in Simpson diversity between the communities. We tested the new partition with artificial data sets and null model comparisons, and applied it to a long‐term data set on plant succession. A key finding is that the effects of total abundance might be very important when comparing two communities, and possibly could account for results from previous studies in which complementarity emerged as an important contributor to BEF.

Waves of attention: patterns and themes of international antimicrobial resistance reports, 1945–2020

This article uses quantitative and qualitative approaches to review 75 years of international policy reports on antimicrobial resistance (AMR). Our review of 248 policy reports and expert consultation revealed waves...

Sensing of Airborne Infochemicals for Green Pest Management: What Is the Challenge?

One of the biggest global challenges for our societies is to provide natural resources to the rapidly expanding population while maintaining sustainable and ecologically friendly products. The increasing public concern about toxic insecticides has resulted in the rapid development of alternative techniques based on natural infochemicals (ICs). ICs (e.g., pheromones, allelochemicals, volatile organic compounds) are secondary metabolites produced by plants and animals and used as information vectors governing their interactions. Such chemical language is the primary focus of chemical ecology, where behavior-modifying chemicals are used as tools for green pest management. The success of ecological programs highly depends on several factors, including the amount of ICs that enclose the crop, the range of their diffusion, and the uniformity of their application, which makes precise detection and quantification of ICs essential for efficient and profitable pest control. However, the sensing of such molecules remains challenging, and the number of devices able to detect ICs in air is so far limited. In this review, we will present the advances in sensing of ICs including biochemical sensors mimicking the olfactory system, chemical sensors, and sensor arrays (e-noses). We will also present several mathematical models used in integrated pest management to describe how ICs diffuse in the ambient air and how the structure of the odor plume affects the pest dynamics.