Neighbor Effects Research Articles

Design of Bimetallic Boronene Structures Leveraging Neighboring Effects for Efficient Electrocatalytic CO2 Reduction Reaction

AbstractElectrocatalytic CO2 reduction (CO2RR) offers a promising avenue to address rising atmospheric CO2 levels by producing high‐value chemicals. However, the development of efficient, long‐lasting catalysts remains challenging. In this study, particle swarm optimization is employed to design a novel bimetallic boronene structure, thereby enhancing CO2RR activity through precise tuning of the metal‐substrate microenvironment. Through high‐throughput screening, seven CuMB4 (M = V, Zn, Nb, Ag, Cd, Ta, Au) monolayers are identified as promising CO2RR catalysts based on stability, conductivity, catalytic activity, and selectivity. These materials, characterized by hyper‐coordination and neighboring bimetallic effects, are proposed for synthesis via self‐assembled surface growth. Notably, CuZnB4 exhibited exceptional theoretical catalytic activity, characterized by remarkably low limiting potentials (UL) of −0.16 V for CH4 and −0.27 V for C2H4, as well as low kinetic barriers of 0.65 and 0.53 eV, respectively. The enhanced activity results from neighboring effects optimizing densely populated boron active sites and the ability to suppress hydrogen evolution reactions. Additionally, this study explored intrinsic properties influencing catalytic activity using volcano plots, descriptor analysis, and electron density evaluation. Unlike traditional catalysts prone to oxidation, CuMB4 varieties possess self‐activating properties, facilitating the conversion of *O/*OH to H2O and enhancing CO2 conversion. This research introduces robust CO2RR catalysts and provides insights into manipulating neighboring effects, thus guiding future catalyst design.

Differences in species composition between calcareous and siliceous herbaceous communities are primarily explained by competition in favourable climates

Difference in vegetation composition between communities from calcareous and siliceous soils might be due to high competition on siliceous soils for species from calcareous origin, and high rock‐induced drought stress on calcareous soils for species from siliceous origin. We tested the hypothesis that, with increasing climate stress, competition should decrease on siliceous rock for species of calcareous origin and drought stress increase on calcareous rock for species of siliceous origin because of decreasing community biomass with increasing cold or drought stress. This question is of high interest for predicting changes in species distribution with climate change since bedrock type and climate change are both complex factors that are likely to interact with climate. We set up a transplant removal experiment in contrasting climate conditions of the south of France, warm and wet temperate, warm and dry Mediterranean, and cold temperate in the Alps and the Pyrenees. In each climate condition, three targets (two species and one population from a third species) from each origin were transplanted with and without neighbours on the two rock types and during two years with different levels of drought stress. Variation in the effects of neighbours and rock‐induced drought stress on transplant survival with and without neighbours were analysed with linear modelling at each site, separately, and with ANCOVA in the whole design. Competition was the highest on siliceous rock in the more favourable climate conditions but for species of siliceous origin. The lower competition found for species of calcareous origin was likely due to the occurrence of allelopathic effects that decreased the negative effect of neighbours as measured with the removal method. The rock‐induced drought stress was the highest on calcareous rock, in particular for species of siliceous origin. Thus, the decrease in competition intensity on siliceous rocks with increasing climate stress was more important for species from siliceous than calcareous origin. Additionally, the importance of the rock‐induced drought stress was relatively low in the most stressful climate conditions as compared to the overwhelming importance of climate drought stress over the two years of our experiment, which likely induced a collapse of the positive effect of growing on a siliceous rock.

‘They adopt, I also adopt’: The neighborhood effects and irrigator farmers’ conversion to adopt water-saving irrigation technology

Promoting water-saving irrigation technology (WSIT) has long been recognized as an effective measure to reduce irrigation water use and alleviate regional water poverty. Neighbours are the groups with the most interaction, the most intensive contact and the most frequent communication in agricultural production. In this paper, based on a field survey of irrigator farmers of China, experiments were conducted to evaluate the contribution of neighbour effect to farmers’ WSIT behaviour and its moderating mechanism between neighbour effect and technology adoption. The results show 26.7 % farmers adopt water-saving technology and these farmers often have strong neighborly relationships. In particular, neighbor effect significantly promote WSIT adoption by 42.1 % and farmers with strong neighborly effects apply significant higher technology compared to farmers with weak neighbourly effects. Furthermore, mechanism results indicated that neighbour effects indirectly influence farmers' adoption of water-saving irrigation technology through three pathways: reducing information search costs, mitigating agricultural production risks and benefiting from the demonstration effect. Moreover, the heterogeneous results report that higher-income, lower digital and lower training frequency farmers will benefit more from the NE in terms of WSIT. Overall, this research provides a micro foundation and policy implications for the promotion of WSIT, and sheds light upon how the government can formulate relevant policies to promote the sustainable development of agricultural water resources.

Strip cropping increases yield and revenue: multi-year analysis of an organic system in the Netherlands

Intercropping is proposed as a promising strategy to meet future food demand while reducing agriculture’s environmental impact by re-diversifying agricultural fields. Strip cropping, a form of intercropping, has a potential to simultaneously deliver multiple ecosystem services including productivity, while facilitating management as strip width can be adjusted to the working width of available machines. While the yield performance of strip cropping systems is influenced by the interaction between neighboring crops, to date, empirical studies on the performance of various crop combinations in strip cropping systems are limited. Here we used three-year data (2020–2022) from a 64-ha organic strip cropping system in the Netherlands to (1) evaluate the effects of crop neighbors and strip cropping on yield and (2) explore if optimizing the allocation of crop neighbors in alternative strip cropping configurations can improve yield and revenue performances. We analyzed the edge effect and strip cropping effect on yield of six crops grown in strips, each neighboring a total of five crops. The yield data was then used to evaluate the performance of the current and alternative strip configurations in terms of LER and relative revenue. Results showed that except for the positive effect observed on potato when neighboring celeriac or broccoli, edge effects lacked statistical significance. Strip cropping effect varied per crop: positive for faba bean and parsnip, neutral for celeriac and potato, and negative for oat and onion. Analysis across crops showed an overall significant positive strip cropping effect on yield. These findings highlighted the value of analysis at the cropping system level in developing designs aimed at unlocking the potential of strip cropping. The positive but variable strip cropping effects observed in the current experimental design and the two alternative configurations suggests prioritizing an overall increased crop diversity over optimizing their spatial arrangement. While we demonstrated increased productivity with strip cropping, further research is needed to expand the database on optimal crop combinations, extending the evaluation beyond yield and revenue performances to facilitate broader adoption of strip cropping in the Netherlands and Western Europe.

Strip‐cropping legacy enhances potato plant defence responses to aphids via soil‐mediated mechanisms

Abstract Intensive agriculture often comes at the expense of soil health. A shift towards practices that foster soil health will support yield and defences against pests and diseases. Growing crops in monoculture is the standard in modern agriculture, though strip‐cropping, in which different crops are planted in strips, is a promising strategy in the transition towards sustainable agriculture. Increasing crop diversity is hypothesized to positively influence arbuscular mycorrhizal fungi (AMF), thereby enhancing soil health, but the mechanisms by which AMF‐plant symbioses contribute to higher yields and reduced pest populations in strip‐cropping systems remain unclear. We used a green‐house experiment with potato plants to explore the soil legacy effects of mono‐cropping versus strip‐cropping systems, AMF inoculation and aphid infestation on AMF root colonization, the induction of plant defences (untargeted LCMS‐based metabolomics), aphid population size and potato yield. We found that potato plants grown in strip‐cropping soil had higher AMF colonization than plants grown in mono‐cropping soil. Potato plants grown in strip‐cropping soil also had higher shoot nitrogen content, increased solamargine levels, and reduced aphid populations. AMF root colonization was only enhanced by the addition of commercial AMF in mono‐cropping soils. Potato plant metabolites were affected by strip‐cropping soil, including jasmonic acid (JA) derivatives. Structural equation models revealed that strip‐cropping soil directly reduced aphid populations and also had a negative direct effect on the JA precursor OPC‐8, and hydroxyJA‐glucosides, indicating complex effects of strip‐cropping soils on JA‐inducible plant defences. Indirect benefits of strip‐cropping soil and AMF inoculation on tuber yield were mediated by their direct positive effects on plant nitrogen content. Our results emphasize the potential of strip‐cropping to enhance AMF root colonization in the field. We show that soil legacy effects of strip‐cropping alter the plant metabolome in ways that suppress of aphid populations. Strip‐cropping legacy effects are the result of crop diversity, crop neighbour and edge effects resulting from crop management practices. While the mechanisms by which soil from strip‐cropping supresses pest populations still need to be identified, our study underscores the potential for strip‐cropping to enhance pest control and yield via soil mediated processes. Read the free Plain Language Summary for this article on the Journal blog.

Reducing herbivory in mixed planting by genomic prediction of neighbor effects in the field

Genetically diverse populations can increase plant resistance to natural enemies. Yet, beneficial genotype pairs remain elusive due to the occurrence of positive or negative effects of mixed planting on plant resistance, respectively called associational resistance or susceptibility. Here, we identify key genotype pairs responsible for associational resistance to herbivory using the genome-wide polymorphism data of the plant species Arabidopsis thaliana. To quantify neighbor interactions among 199 genotypes grown in a randomized block design, we employ a genome-wide association method named “Neighbor GWAS” and genomic prediction inspired by the Ising model of magnetics. These analyses predict that 823 of the 19,701 candidate pairs can reduce herbivory in mixed planting. We planted three pairs with the predicted effects in mixtures and monocultures, and detected 18–30% reductions in herbivore damage in the mixed planting treatment. Our study shows the power of genomic prediction to assemble genotype mixtures with positive biodiversity effects.

Exploiting Neighbor Effect: Conv-Agnostic GNN Framework for Graphs With Heterophily.

Due to the homophily assumption in graph convolution networks (GCNs), a common consensus in the graph node classification task is that graph neural networks (GNNs) perform well on homophilic graphs but may fail on heterophilic graphs with many interclass edges. However, the previous interclass edges' perspective and related homo-ratio metrics cannot well explain the GNNs' performance under some heterophilic datasets, which implies that not all the interclass edges are harmful to GNNs. In this work, we propose a new metric based on the von Neumann entropy to reexamine the heterophily problem of GNNs and investigate the feature aggregation of interclass edges from an entire neighbor identifiable perspective. Moreover, we propose a simple yet effective Conv-Agnostic GNN framework (CAGNNs) to enhance the performance of most GNNs on the heterophily datasets by learning the neighbor effect for each node. Specifically, we first decouple the feature of each node into the discriminative feature for downstream tasks and the aggregation feature for graph convolution (GC). Then, we propose a shared mixer module to adaptively evaluate the neighbor effect of each node to incorporate the neighbor information. The proposed framework can be regarded as a plug-in component and is compatible with most GNNs. The experimental results over nine well-known benchmark datasets indicate that our framework can significantly improve performance, especially for the heterophily graphs. The average performance gain is 9.81%, 25.81%, and 20.61% compared with graph isomorphism network (GIN), graph attention network (GAT), and GCN, respectively. Extensive ablation studies and robustness analysis further verify the effectiveness, robustness, and interpretability of our framework. Code is available at https://github.com/JC-202/CAGNN.

Odour information enables patch choice by mammalian herbivores from afar, leading to predictable plant associational effects

Abstract Neighbouring plants can alter the susceptibility of high‐quality focal plants to herbivores by affecting herbivore patch choice. Herbivores can use plant odour to make patch‐scale foraging decisions from afar, but the actual information they rely on within complex plant odours is rarely defined. Revealing the information enabling patch choice by herbivores will provide the mechanistic link underpinning associational effects of plant neighbours arising from these foraging decisions. Here, our first aim was to test whether odour cues alone enable a mammalian herbivore to make patch choice decisions leading to predictable associational effects of neighbours on high‐quality focal plants. Our second aim was then to test whether artificial odour, designed to mimic the informative odour component within the whole odour profile of low‐quality neighbours, is as effective as real plants in influencing patch choice and associational refuge. We tested patch choice by African elephants, Loxodonta africana using a giant Y‐maze and real or artificial plant odours as the only cues for the neighbours of a high‐quality focal plant. We quantified the probability of various odour treatments being chosen in comparison with the odour of a focal plant alone. Compared with focal plants alone, we found that elephants were more likely to choose patches with the focal plant plus high‐quality neighbours of the same or different species, but less likely to choose patches with the focal plant plus low‐quality neighbours. We also demonstrated that an artificial subset of odours, designed to be informative, were as effective as real low‐quality neighbours in influencing patch choice and hence associational refuge to the focal plant. Our results demonstrate a key role of plant odour—and specifically informative components within complex odour profiles—in patch choice decisions by a mammalian herbivore, leading to plant associational effects on high‐quality focal plants. Understanding what olfactory information herbivores use when deciding which patches to visit or avoid, and how it affects focal plant susceptibility is important ecologically. Non‐random patch choice will not only affect individual fitness of herbivores, but also shape plant community dynamics through impacting plant survival and recruitment. Furthermore, artificially re‐creating odour information could offer a new tool to influence herbivore foraging decisions, with implications for wildlife management and conservation, including plant protection. Read the free Plain Language Summary for this article on the Journal blog.

Plant neighbors differentially alter a focal species' biotic interactions through changes to resource allocation.

Plant resource allocation strategies are thought to be largely a consequence of changing abiotic conditions and evolutionary history. However, biotic interactions also influence how a plant allocates resources. As a result, plants mediate indirect interactions between organisms above- and belowground through resource allocation. Neighboring plants can influence plant fitness directly through competition for resources, and indirectly by altering associated community interactions (associational effects), such as pollination, herbivory, and a suite of belowground interactions. Given the importance of community interactions for plant success, and the known ability for plant neighbors to change these interactions, the goal of this "pandemic project" was to understand how heterospecific plant neighbors alter plant resource allocation, whether this occurred through above- or belowground mechanisms, and whether this in turn alters biotic interactions and the relationship between a focal plant and its herbivore and soil community interactions. To do so, we established a common garden experiment, manipulating plant neighbor identity and the extent of interaction among neighbors (aboveground only, vs. above- and belowground interactions, using customized pot types), and measured changes to a focal plant and its biotic interactions over two growing seasons. We found evidence of both neighbor effects and pot type, showing that neighbor interactions affect a focal plant through both above- and belowground processes, and how the focal plant is affected depends on neighbor identity. Though neighbors did not directly alter herbivory or most soil microbial interactions, they did alter the relationship between belowground microbial communities and a plant response trait (specific leaf area). Plant resource allocation responses were reduced with time, showing the importance of extending experiments beyond a single growing season, and are an important consideration when making predictions about plant responses to changing conditions. This study contributes to a growing body of work showing how community contexts affect the above- and belowground interactions of a plant through plant resource allocation strategies.

Seasonal Abundance and Diversity of Culicoides Biting Midges in Livestock Sheds in Kanchanaburi Province, Thailand.

Culicoides biting midges were collected using UV light traps from nine livestock farms in Kanchanaburi Province, Thailand. Collections were made one night per month from June 2020 to May 2021 to determine the seasonal changes and spatial distribution of the Culicoides assemblage. The influence of four environmental factors (temperature, rainfall, humidity, and wind speed), types of animals in each shed (cattle, pigs, and avians), and neighboring animals (those in the other sheds and their proximity) were assessed. A subsample of 130,670 out of a total of 224,153 specimens collected was identified and counted. The collections were predominantly female (76.9%), though males were also commonly collected (23.1%). The dominant species included C. peregrinus (97,098 individuals; 43.0%), C. oxystoma (55,579; 24.6%), C. arakawae (45,996; 20.4%), and C. imicola (15,703; 7.0%), while other species accounted for the remaining 9777 individuals (4.4%). Trap captures were strongly influenced by seasons and animal sheds. Cattle exhibited the greatest effect on the community, likely due to their large biomass. Humidity and temperature had a positive effect on trap captures, whereas wind speed exhibited a negative effect. Cattle positively influenced all major species, except for C. arakawae, which showed a positive association with avians. A "neighboring effect" was also observed. Additionally, the lowest dispersal ability of C. arakawae was suggested.

Phylogenetic relatedness and habitat affect seedling abundance of a mid-montane humid evergreen broad-leaved forest in the Gaoligong Mountains, Southwestern China

The neighborhood effect has become an important framework with which to study the mechanisms that maintain the coexistence of tree species. Phylogenetic relatedness among neighboring plants directly affects species coexistence and the maintenance of tree diversity. And some studies have reported that seedling performance is negatively correlated with phylogenetic relatedness, which termed phylogenetic negative density dependence. Soil-borne fungal pathogens affected seedling performance of phylogenetically related host species, i.e., phylogenetic Janzen–Connell effect. Seedlings may be particularly vulnerable to habitat and neighbor characteristics. Although previous studies have demonstrated the influence of neighborhood effects, phylogenetic relatedness, and habitat filtering on seedling survival, growth, and mortality, the effect of variation in these factors on seedling abundance remains unclear. To address this question, we used a 4-ha (200 m × 200 m) and monitored four-year (2020–2023) seedling dataset from a mid-montane humid evergreen broad-leaved subtropical forest in the Gaoligong Mountains, Yunnan, Southwestern China, and which consisted of 916 seedlings belonging to 56 species. The results of generalized linear mixed models showed no significant effect of conspecific adult neighbors on seedling abundance at any of the intervals evaluated. In contrast, we found evidence of phylogenetic distance density dependence in the forests of the Gaoligong Mountains. Specifically, there was a significant positive effect of the relative average phylogenetic distance between heterospecific adult neighbors and focal seedlings on focal seedling abundance in 2020; however, the relative average phylogenetic distance between heterospecific seedling neighbors and focal seedlings had a significant negative effect on seedling abundance over the four-year period (2020–2023). Among the habitat factors, only light (canopy opening) had a negative effect on seedling abundance in all four years. Light resources may be a limiting factor for seedlings, and determine seedling dynamics in subtropical forests. Overall, our results demonstrated that phylogenetic density dependence and habitat filtering affected subtropical seedling abundance. Our findings provide new evidence of the impact of phylogenetic density dependence on seedling abundance in a subtropical mid-montane humid evergreen broad-leaved forest and highlight the need to incorporate the neighborhood effect, phylogenetic relatedness, and habitat factors in models assessing seedling abundance.

Molecular Diversity of Ectomycorrhizal Fungi in Relation to the Diversity of Neighboring Plant Species.

(1) Background: Plant diversity has long been assumed to predict soil microbial diversity. The mutualistic symbiosis between forest trees and ectomycorrhizal (EM) fungi favors strong correlations of EM fungal diversity with host density in terrestrial ecosystems. Nevertheless, in contrast with host tree effects, neighboring plant effects are less well studied. (2) Methods: In the study presented herein, we examined the α-diversity, community composition, and co-occurrence patterns of EM fungi in Quercus acutissima across different forest types (pure forests, mixed forests with Pinus tabuliformis, and mixed forests with other broadleaved species) to ascertain how the EM fungi of focal trees are related to their neighboring plants and to identify the underlying mechanisms that contribute to this relationship. (3) Results: The EM fungal community exhibited an overall modest but positive correlation with neighboring plant richness, with the associations being more pronounced in mixed forests. This neighboring effect was mediated by altered abiotic (i.e., SOC, TN, LC, and LP) and biotic (i.e., bacterial community) factors in rhizosphere soil. Further analysis revealed that Tomentella_badia, Tomentella_galzinii, and Sebacina_incrustans exhibited the most significant correlations with plant and EM fungal diversity. These keystone taxa featured low relative abundance and clear habitat preferences and shared similar physiological traits that promote nutrient uptake through contact, short-distance and medium-distance smooth contact-based exploration types, thereby enhancing the potential correlations between EM fungi and the neighboring plant community. (4) Conclusions: Our findings contribute to the comprehension of the effect of neighboring plants on the EM fungal community of focal trees of different forest communities and the biodiversity sensitivity to environmental change.

Harnessing Water Competition to Drive Enzyme Crosstalk.

In nature, enzymatic pathways often involve compartmentalization effects that can modify the intrinsic activity and specificity of the different enzymes involved. Consequently, extensive research has focused on replicating and studying the compartmentalization effects on individual enzymes and on multistep enzyme "cascade" reactions. This study explores the influence of compartmentalization achieved using molecular crowding on the glucose oxidase/horseradish peroxidase (GOx/HRP) cascade reaction. The crowder tested is methoxy poly(ethylene glycol) (mPEG) that can, depending on conditions, promote GOx and HRP coassociation at the nanoscale and extend their contact time. Low-molecular-weight mPEG (0.35 kDa), but not mPEG of higher molecular weights (5 or 20 kDa), significantly enhanced the cascade reaction where up to a 20-fold increase in the rate of the cascade reaction was observed under some conditions. The combined analyses emphasize the particularity of low-molecular-weight mPEG and point toward mPEG-induced coassociation of HRP and GOx, producing nearest crowded neighbor effects of HRP on GOx, and vice versa. These altered the nanoscale environments of these enzymes, which influenced substrate affinity. Using mPEG to promote protein coassociation is simple and does not chemically modify the proteins studied. This approach could be of interest for more broadly characterizing nearest crowded neighbor effects (i.e., protein-protein interactions) for multiprotein systems (i.e., more than just two), thus making it an interesting tool for studying very complex systems, such as those found in nature.

Expanding the neighbourhood watch: Orthographic neighbours in isiXhosa reading and spelling

Background: Lexical properties such as orthographic neighbours have been shown to have an influence on reading and writing; however, this phenomenon is yet to be explored in the Southern Bantu languages.Objectives: We investigate the role of orthographic neighbourhood density and neighbourhood frequency in reading and spelling in Grade 3 isiXhosa home-language learners. The aim is to establish whether orthographic neighbours facilitate or hinder reading and spelling. The dual-route model of orthographic processing is used to interpret our findings.Method: Data were collected from 97 Grade 3 isiXhosa home-language learners. Lexical decision, word reading, and spelling tasks were administered. Tasks included both real and pseudowords varying in orthographic neighbourhood density and neighbourhood frequency, while controlling for word length and word frequency.Results: Findings show a significant inhibitory effect of orthographic neighbourhood frequency and word length for spelling accuracy. Longer words with higher frequency neighbours were more likely to be spelt incorrectly. No effect was recorded for the lexical decision and word reading tasks.Conclusion: Our findings suggest that spelling in isiXhosa relies partially on lexical processing strategies, which allows for the inhibitory effects of orthographic neighbours to be observed. While in reading, sublexical processing is more prominent, therefore mitigating the effect of orthographic neighbours.Contribution: Empirical evidence for the effects of orthographic neighbours, specifically in a Southern Bantu language, provides a clearer picture of the underlying cognitive-linguistic processes involved in reading and writing. This evidence may contribute to the development of targeted pedagogical practices to address spelling errors.

Social selection analysis reveals limited effect of neighbors' traits in Tree swallows.

Social interactions are ubiquitous in nature and can shape the fitness of individuals through social selection. This type of selection arises when phenotypes of neighbors influence the fitness of a focal individual. Quantifying social selection is crucial to better characterize the overall selective landscape. For example, if intraspecific competition is strong, traits that are beneficial for an individual could be detrimental to competitors. In this study, we quantified social selection acting on three key ecological traits (body mass, wing length, and laying date) in wild Tree swallow (Tachycineta bicolor) females. We used reproductive success measured at three stages throughout the breeding season as fitness proxies to assess selection acting at those decisive moments. We also quantified the effects of environment on selection using measures of conspecifics' density, type of agricultural landscape, and presence of interspecific competitors. Overall, we found no strong evidence of social selection on these traits in our study system, although there were marginally nonsignificant selection gradients suggesting the positive effect of larger neighbors. Environmental variables affected reproductive success but did not strongly affect social selection gradients. Our study calls for more social selection estimates to be reported across environments to better understand its importance in wild populations.

Functional diversity of neighbours mediates sap flow density and radial growth of focal trees, but in different ways between evergreen and deciduous broadleaved species

Abstract The functioning of a tree is shaped by the neighbouring species through the interspecific interaction and local environments. The functional trait composition of the neighbourhood could provide mechanistic insights into the effects of neighbours on the resource strategies of focal trees. In this study, we deployed an automated high‐frequency measurement of the sap flow density (SFD) and the radial growth of 48 trees of 12 species at BEF‐China, a large‐scale forest biodiversity manipulation experiment, to investigate the consequences and underlying mechanisms of the functional trait composition of the neighbourhood on the sap flow and radial growth of focal trees. We found a positive relationship between SFD and growth, reflecting the important supportive role of sap flow in tree growth. High functional diversity (FD) of the neighbourhood depressed SFD but promoted growth when considering all species, and thus promoted water‐use efficiency. Acquisitiveness of neighbouring trees positively affected growth, suggesting interspecific facilitation. Furthermore, neighbourhood FD benefits evergreen focal trees by promoting growth. However, in deciduous focal trees, neighbourhood FD reduced SFD but had no significant effects on growth. Our findings suggest that considering the functional trait composition of neighbourhood communities will support effective afforestation and forest management. Read the free Plain Language Summary for this article on the Journal blog.

The nasty neighbor effect in humans.

Like other group-living species, humans often cooperate more with an in-group member than with out-group members and strangers. Greater in-group favoritism should imply that people also compete less with in-group members than with out-group members and strangers. However, in situations where people could invest to take other's resources and invest to protect against exploitation, we observed the opposite. Akin to what in other species is known as the "nasty neighbor effect," people invested more when facing an in-group rather than out-group member or stranger across 51 nations, in different communities in Kenya, and in representative samples from the United Kingdom. This "nasty neighbor" behavior is independent of in-group favoritism in trust and emerges when people perceive within-group resource scarcity. We discuss how to reconcile that humans exhibit nastiness and favoritism toward in-group members with existing theory on in-group favoritism.

Consistent dear enemy effect despite variation in territorial centrality and population density in Rufous Horneros

ABSTRACT Social discrimination is used as a territorial cost-mitigation behaviour across several taxonomic groups. However, whether this phenomenon is similar across populations or varies due to local ecological traits remains an open field. Here, we tested whether social discrimination ability exhibited by pairs of Rufous Horneros (Furnarius rufus) varies between two spatially distinct Brazilian populations (Brasília and Juiz de Fora), with contrasting population densities. We predicted that Rufous Horneros would show the highest aggression towards strangers’ duets in the low-density population (the ‘dear enemy effect’), and towards neighbours’ duets in the high-density population (the ‘nasty neighbour effect’). We also examined the impact of territorial centrality (distance to the centre of the conspecific neighbourhood) on territorial responses, assuming that territorial harassment varies with centrality. We observed a consistent dear enemy effect expression (i.e. lower response to simulated intrusions by neighbours compared to strangers) across both populations, despite their differing densities. Additionally, we found no effect of territorial centrality on playback responses. Our findings show that the dear enemy effect is widely distributed in Rufous Horneros, at least in the breeding season, being observed even in a high-density population. Our findings also highlight the lack of advantages for central territories. Future studies should investigate whether territorial mitigation strategies exhibit consistency across different contexts and taxa.

Neighbour effects on plant biomass and its allocation for forbs growing in heterogeneous soils

Abstract Focal plants are considerably affected by their neighbouring plants, especially when growing in heterogeneous soils. A previous study on grasses demonstrated that soil heterogeneity and species composition affected plant biomass and above- and belowground allocation patterns. We now tested whether these findings were similar for forbs. Three forb species (i.e. Spartina anglica, Limonium bicolor and Suaeda glauca) were grown in pots with three levels of soil heterogeneity, created by alternatively filling resource-rich and resource-poor substrates using small, medium or large patch sizes. Species compositions were created by growing these forbs either in monocultures or in mixtures. Results showed that patch size × species composition significantly impacted shoot biomass, root biomass and total biomass of forbs at different scales. Specifically, at the pot scale, shoot biomass, root biomass and total biomass increased with increasing patch size. At the substrate scale, shoot biomass and total biomass were higher at the large patch size than at the medium patch size, both in resource-rich and resource-poor substrates. Finally, at the community scale, monocultures had more shoot biomass, root biomass and total biomass than those in the two- or three-species mixtures. These results differ from earlier findings on the responses of grasses, where shoot biomass and total biomass decreased with patch size, and more shoot biomass and total biomass were found in resource-rich than resource-poor substrates. To further elucidate the effects of soil heterogeneity on the interactions between neighbour plants, we advise to conduct longer-term experiments featuring a variety of functional groups.

Red2Flpe-SCON: a versatile, multicolor strategy for generating mosaic conditional knockout mice

Image-based lineage tracing enables tissue turnover kinetics and lineage potentials of different adult cell populations to be investigated. Previously, we reported a genetic mouse model system, Red2Onco, which ectopically expressed mutated oncogenes together with red fluorescent proteins (RFP). This system enabled the expansion kinetics and neighboring effects of oncogenic clones to be dissected. We now report Red2Flpe-SCON: a mosaic knockout system that uses multicolor reporters to label both mutant and wild-type cells. We develop the Red2Flpe mouse line for red clone-specific Flpe expression, as well as the FRT-based SCON (Short Conditional IntrON) method to facilitate tunable conditional mosaic knockouts in mice. We use the Red2Flpe-SCON method to study Sox2 mutant clonal analysis in the esophageal epithelium of adult mice which reveal that the stem cell gene, Sox2, is less essential for adult stem cell maintenance itself, but rather for stem cell proliferation and differentiation.