Ecological Scales Research Articles

Multiple axes of visual system diversity in Ithomiini, an ecologically diverse tribe of mimetic butterflies.

The striking structural variation seen in arthropod visual systems can be explained by the overall quantity and spatio-temporal structure of light within habitats coupled with developmental and physiological constraints. However, little is currently known about how fine-scale variation in visual structures arises across shorter evolutionary and ecological scales. In this study, we characterise patterns of interspecific (between species), intraspecific (between sexes) and intraindividual (between eye regions) variation in the visual system of four ithomiine butterfly species. These species are part of a diverse 26-million-year-old Neotropical radiation where changes in mimetic colouration are associated with fine-scale shifts in ecology, such as microhabitat preference. Using a combination of selection analyses on visual opsin sequences, in vivo ophthalmoscopy, micro-computed tomography (micro-CT), immunohistochemistry, confocal microscopy and neural tracing, we quantify and describe physiological, anatomical and molecular traits involved in visual processing. Using these data, we provide evidence of substantial variation within the visual systems of Ithomiini, including: (i) relaxed selection on visual opsins, perhaps mediated by habitat preference, (ii) interspecific shifts in visual system physiology and anatomy, and (iii) extensive sexual dimorphism, including the complete absence of a butterfly-specific optic neuropil in the males of some species. We conclude that considerable visual system variation can exist within diverse insect radiations, hinting at the evolutionary lability of these systems to rapidly develop specialisations to distinct visual ecologies, with selection acting at the perceptual, processing and molecular level.

Domestication shapes the pig gut microbiome and immune traits from the scale of lineage to population.

Animal ecology and evolution have long been known to shape host physiology, but more recently, the gut microbiome has been identified as a mediator between animal ecology and evolution and health. The gut microbiome has been shown to differ between wild and domestic animals, but the role of these differences for domestic animal evolution remains unknown. Gut microbiome responses to new animal genotypes and local environmental change during domestication may promote specific host phenotypes that are adaptive (or not) to the domestic environment. Because the gut microbiome supports host immune function, understanding the effects of animal ecology and evolution on the gut microbiome and immune phenotypes is critical. We investigated how domestication affects the gut microbiome and host immune state in multiple pig populations across five domestication contexts representing domestication status and current living conditions: free-ranging wild, captive wild, free-ranging domestic, captive domestic in research or industrial settings. We observed that domestication context explained much of the variation in gut microbiome composition, pathogen abundances and immune markers, yet the main differences in the repertoire of metabolic genes found in the gut microbiome were between the wild and domestic genetic lineages. We also documented population-level effects within domestication contexts, demonstrating that fine scale environmental variation also shaped host and microbe features. Our findings highlight that understanding which gut microbiome and immune traits respond to host genetic lineage and/or scales of local ecology could inform targeted interventions that manipulate the gut microbiome to achieve beneficial health outcomes.

Environmental Concerns, Communal Orientation, and Environmental Self-Efficacy as Predictors of Ecologically Conscious Consumer Behaviour Among Young Adults

The quintessential era of 21st century is well-known for rapid industrialization and growth. Expansion of industrialization has resulted in massive environmental damage leading to several environmental concerns such as global warming, pollution, non-biodegradable wastes, and frequent climatic changes. To combat the threat of environmental damage, ‘Green or eco-friendly products’ has gained enormous attention from both commodities producers and consumers. In no time, there has been an increase in demand for eco-friendly products by consumers globally. Reports have that the young population showed a vigilant interest in adapting to green marketing strategies as a part of their daily routine. However, it is crucial to understand the underlying psycho-social factors responsible for young consumers’ decision-making process while engaging in green purchase behaviour as they will be significantly contributing to nature being the proactive and highly conscious generation. Therefore, the present study aims to understand the role of environmental concerns or attitudes, communal orientation and environmental self-efficacy as the predictors of pro-environmental purchase behaviour among young adults. The cross-sectional survey study was conducted on 150 young adults between the age range of 18-34 years. Psychometric tools i.e., pro-environmental purchase behaviour scale (PPS) [1], new ecological paradigms scale (NEPS) [2], communal orientation scale (COS) [3] and environmental self-efficacy scale (ESE-20) [4] were used for data collection. Mean, standard deviation, Pearson correlation and regression analysis were computed to statistically analyse the obtained data. Findings of the study aid in gaining insight into motives and intentions related to pro-environmental behaviour engagement among young population. It will help in formulating better public and environmental interventions and policies for strengthening and safeguarding the environment and maintaining sustainability.

The Self-Efficacy Perception for Environmental Education and Ecological Footprint Awareness of the Child Development Programme Students

Abstract The purpose of this study was to examine the correlation between the self-efficacy perception for environmental education and ecological footprint awareness of the child development programme students. Sample group of the study which was carried out according to the correlational survey model was specified according to convenience sampling. The sample group consisted of students studying in child development departments in four universities in Turkey. In the study, “Self-Efficacy Scale for Environmental Education” and “Ecological Footprint Awareness Scale” were used as data collection tools. For the data analysis, the Kolmogorov-Smirnov, t, variance tests and The Spearman’s correlation coefficient was used. In the research results, it was revealed that the environmental education self-efficacy perception and ecological footprint awareness levels of the students of the child development programme positively affect each other at a moderate level.

A Multiscale Spatiotemporal Epidemiological Analysis of Neighborhood Correlates of Triple-Negative Breast Cancer.

Women living in disadvantaged neighborhoods present with increased prevalence rates of triple-negative breast cancer (TNBC). This study takes a spatiotemporal epidemiological approach to understand the impact of socioenvironmental contextual factors on TNBC prevalence rates. We analyzed 935 TNBC cases from a major cancer center registry, between 2005 and 2017, to explore spatial and space-time clusters of TNBC prevalence rates at the census tract and neighborhood scales. Spatial regression analysis was performed to examine relationships between nine socioenvironmental factors and TNBC prevalence rates at both ecological scales. We observed spatial clustering of high TNBC prevalence rates along a north-south corridor of Miami-Dade County along Interstate 95, a region containing several majority non-Hispanic Black neighborhoods. Among the ecologic measures, the percent of a region designated as a brownfield was associated with TNBC prevalence rates at the tract-level (β = 4.27; SE = 1.08; P < 0.001) and neighborhood-level (β = 8.61; SE = 2.20; P < 0.001). Our spatiotemporal analysis identified robust patterns of hot spots of TNBC prevalence rates in a corridor of several disadvantaged neighborhoods in the northern half of the county. These patterns of TNBC align with the literature regarding at-risk groups and neighborhood-level effects on TNBC; however, remain to be validated in a population-based sample. Spatial epidemiological approaches can help public health officials and cancer care providers improve place-specific screening, patient care, and understanding of socioenvironmental factors that may shape breast cancer subtype through gene-environment and epigenetic interactions.

Marine reserves promote cycles in fish populations on ecological and evolutionary time scales.

Marine reserves are considered essential for sustainable fisheries, although their effectiveness compared to traditional fisheries management is debated. The effect of marine reserves is mostly studied on short ecological time scales, whereas fisheries-induced evolution is a well-established consequence of harvesting. Using a size-structured population model for an exploited fish population of which individuals spend their early life stages in a nursery habitat, we show that marine reserves will shift the mode of population regulation from low size-selective survival late in life to low, early-life survival due to strong resource competition. This shift promotes the occurrence of rapid ecological cycles driven by density-dependent recruitment as well as much slower evolutionary cycles driven by selection for the optimal body to leave the nursery grounds, especially with larger marine reserves. The evolutionary changes increase harvesting yields in terms of total biomass but cause disproportionately large decreases in yields of larger, adult fish. Our findings highlight the importance of carefully considering the size of marine reserves and the individual life history of fish when managing eco-evolutionary marine systems to ensure both population persistence as well as stable fisheries yields.

The Anthropocene condition: evolving through social-ecological transformations.

Anthropogenic planetary disruptions, from climate change to biodiversity loss, are unprecedented challenges for human societies. Some societies, social groups, cultural practices, technologies and institutions are already disintegrating or disappearing as a result. However, this coupling of socially produced environmental challenges with disruptive social changes-the Anthropocene condition-is not new. From food-producing hunter-gatherers, to farmers, to urban industrial food systems, the current planetary entanglement has its roots in millennia of evolving and accumulating sociocultural capabilities for shaping the cultured environments that our societies have always lived in (sociocultural niche construction). When these transformative capabilities to shape environments are coupled with sociocultural adaptations enabling societies to more effectively shape and live in transformed environments, the social-ecological scales and intensities of these transformations can accelerate through a positive feedback loop of 'runaway sociocultural niche construction'. Efforts to achieve a better future for both people and planet will depend on guiding this runaway evolutionary process towards better outcomes by redirecting Earth's most disruptive force of nature: the power of human aspirations. To guide this unprecedented planetary force, cultural narratives that appeal to human aspirations for a better future will be more effective than narratives of environmental crisis and overstepping natural boundaries. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'.

FORMS: Forest Multiple Source height, wood volume, and biomass maps in France at 10 to 30 m resolution based on Sentinel-1, Sentinel-2, and Global Ecosystem Dynamics Investigation (GEDI) data with a deep learning approach

Abstract. The contribution of forests to carbon storage and biodiversity conservation highlights the need for accurate forest height and biomass mapping and monitoring. In France, forests are managed mainly by private owners and divided into small stands, requiring 10 to 50 m spatial resolution data to be correctly separated. Further, 35 % of the French forest territory is covered by mountains and Mediterranean forests which are managed very extensively. In this work, we used a deep-learning model based on multi-stream remote-sensing measurements (NASA's Global Ecosystem Dynamics Investigation (GEDI) lidar mission and ESA's Copernicus Sentinel-1 and Sentinel-2 satellites) to create a 10 m resolution canopy height map of France for 2020 (FORMS-H). In a second step, with allometric equations fitted to the French National Forest Inventory (NFI) plot data, we created a 30 m resolution above-ground biomass density (AGBD) map (Mg ha−1) of France (FORMS-B). Extensive validation was conducted. First, independent datasets from airborne laser scanning (ALS) and NFI data from thousands of plots reveal a mean absolute error (MAE) of 2.94 m for FORMS-H, which outperforms existing canopy height models. Second, FORMS-B was validated using two independent forest inventory datasets from the Renecofor permanent forest plot network and from the GLORIE forest inventory with MAE of 59.6 and 19.6 Mg ha−1, respectively, providing greater performance than other AGBD products sampled over France. Finally, we compared FORMS-V (for volume) with wood volume estimations at the ecological region scale and obtained an R2 of 0.63 with an MAE of 30 m3 ha−1. These results highlight the importance of coupling remote-sensing technologies with recent advances in computer science to bring material insights to climate-efficient forest management policies. Additionally, our approach is based on open-access data having global coverage and a high spatial and temporal resolution, making the maps reproducible and easily scalable. FORMS products can be accessed from https://doi.org/10.5281/zenodo.7840108 (Schwartz et al., 2023).

How does trait variance partitioning help us to understand plant community assembly? The example of pond communities in the Kerguelen Islands

AbstractQuestionIn the current context of biodiversity erosion, functional approaches to the examination of community assembly mechanisms and better prediction of plant species fates have emerged. The assessment of trait variation patterns should be a powerful means of identifying community assembly mechanisms. However, most studies of trait variations and their consequences for individual performance (i.e., vegetative biomass) are usually incomplete as they focused on single ecological scales or filters, with no consideration of relationships between traits. Such research has provided a fragmented view of plant community assembly.LocationWe examined macrophyte communities living in ponds of the sub‐Antarctic Iles Kerguelen.MethodsWe measured traits related to resource acquisition and conservation in all occurring species, and examined their variation across temporal (years), spatial (sites), and taxonomic (between and within species) scales and in response to multiple abiotic and biotic habitat variables. The consequences of these trait variations and the effects of their correlation for plant individual performance were also explored.ResultsTrait distributions were fairly conserved among sites, whereas we observed a large amount of intraspecific trait variation enabling individuals to resist filters. Responses to biotic and/or abiotic variables were trait‐dependent, and simultaneous trait responses should enable individual plants to face several simultaneous constraints. Almost all traits had direct or indirect effects on individual performance, indicating the need to consider trait relationships.ConclusionThe partitioning of trait variance is a relevant approach to the identification of the scale at which the most decisive processes for plant community assembly operate without the interference of scale dependency issues, and should orient further research. In addition, several biotic and abiotic variables should be considered in future studies to better understand the effects of environmental changes on plant communities.

Development and Validation of the Social Ecological Resilience Scale (SERS) from a Systems Perspective for Hong Kong Families

This study examined the construct of resilience from a systems perspective and developed a new Social Ecological Resilience Scale measuring resilience in Hong Kong families. A total of 506 service users were recruited using convenience sampling. Exploratory Factor Analysis was used to uncover the factor structures, while Confirmatory Factor Analysis was conducted to test the scale’s internal reliability and validity. A 44-item scale with a six-factor structure comprising emotional flexibility, coping, self-kindness, common humanity, family support and social support was revealed. The implications for conceptualizing resilience from a broader socio-cultural perspective and developing interventions are discussed.

Standardization of in situ coral bleaching measurements highlights the variability in responses across genera, morphologies, and regions.

Marine heatwaves and regional coral bleaching events have become more frequent and severe across the world's oceans over the last several decades due to global climate change. Observational studies have documented spatiotemporal variation in the responses of reef-building corals to thermal stress within and among taxa across geographic scales. Although many tools exist for predicting, detecting, and quantifying coral bleaching, it remains difficult to compare bleaching severity (e.g., percent cover of bleached surface areas) among studies and across species or regions. For this review, we compiled over 2,100 in situ coral bleaching observations representing 87 reef-building coral genera and 250 species of common morphological groups from a total of 74 peer-reviewed scientific articles, encompassing three broad geographic regions (Atlantic, Indian, and Pacific Oceans). While bleaching severity was found to vary by region, genus, and morphology, we found that both genera and morphologies responded differently to thermal stress across regions. These patterns were complicated by (i) inconsistent methods and response metrics across studies; (ii) differing ecological scales of observations (i.e., individual colony-level vs. population or community-level); and (iii) temporal variability in surveys with respect to the onset of thermal stress and the chronology of bleaching episodes. To improve cross-study comparisons, we recommend that future surveys prioritize measuring bleaching in the same individual coral colonies over time and incorporate the severity and timing of warming into their analyses. By reevaluating and standardizing the ways in which coral bleaching is quantified, researchers will be able to track responses to marine heatwaves with increased rigor, precision, and accuracy.

Aridity Gradients Shape Intraspecific Variability of Morphological Traits in Native Ceratonia siliqua L. of Morocco.

The carob tree (Ceratonia siliqua L.) is a significant fruit tree in the Mediterranean region with cultural, biological, and ecological importance. Despite its importance, intraspecific trait variability (ITV) in carob trees has been largely overlooked in previous studies. Understanding ITV and its relationship with environmental conditions is crucial for conservation and breeding programs. In this study, we investigated the variability of carob pod and seed-related traits across different ecological scales in 25 studied populations in Morocco. Significant differences in morphological traits were observed between carob populations at various ecological levels, and pod-related traits exhibited greater variability than seed traits. Correlation analysis revealed strong associations between carob morphological traits and environmental conditions, with altitude and aridity index playing an influential role. The aridity gradient was strongly related to changes in pod size, seed number, and size, as well as seed yield. Our findings highlight an important ITV reaching 45% at the intra-population level, 36.5% at the inter-geographic level, and 30% at the inter-population level. Overall, this study contributes valuable insights into the ecology and adaptation of carob trees, emphasizing the importance of considering intraspecific variability when studying this remarkable species. This knowledge is critical for addressing the challenges posed by climate change and human activities on the long-term survival and ecological functioning of carob populations.

Качество древесного опада как информативный индикатор функциональной классификации лесов

Relevance and goals. In the context of global climate change, the climate-regulating function of forests deserves special attention. There is still no functional classification of forests according to the effectiveness of carbon accumulation function. The aim of this paper is to discuss an approach to such classification based on the assessment of tree litter quality. Objects and methods. To test the approach to the identification of functional types of forests based on the quality of tree litter, taking into account the location in the geochemically linked landscape and the mechanical composition of soil-forming rocks, data on soils and vegetation obtained at 23 testing sites in the subzone of coniferous-broadleaf forests of the European part of Russia on the territory of Bryansk Polesie and Moskvoretsko-Okskaya plain were used. For indirect (Landolt’s ecological scales using the SpeDiv program) assessment of differences in the soil richness in forests belonging to different functional types, the species composition at 160 geobotanical plots in forest sites in the Moscow, Bryansk, Smolensk, Kostroma Regions, Krasnodar Territory, and the Republic of Adygea (Northwestern Caucasus) were analyzed. Results. Examples of functional forest types for coniferous — broad-leaved forests of the European part of Russia are given. The differences in soil carbon stock between forests belonging to different functional types were found, and a preliminary assessment of the influence of the location in the geochemically linked landscape and the mechanical composition of soils on the accumulation of carbon in soils in the same functional forest types is given. Conclusion. Based on the quality of the tree litter, 15 functional forest types were identified, which are confirmed by examples of forests in the subzone of coniferous-broad-leaved forests of the European part of Russia and in the belt of coniferous-broad-leaved forests of the Northwestern Caucasus. The validity of identification of functional forest types for the efficiency of carbon accumulation in soils based on the quality of tree litter, taking into account the influence of “external factors” (the location of forests in the geochemically linked landscape and the mechanical composition of soil-forming rocks), was confirmed by data obtained at 23 sites. Using this approach allowed us to reveal differences in the soil carbon stock and related characteristics of soil fertility estimated on an ecological scale between the functional forest types, identified on the base of tree litter in the mixed, coniferous-broad-leaved forests at the same location in the geochemically linked landscape. Differences in soil carbon stocks in forest ecosystems of the same functional forest types formed on clay loam and sandy loam soil-forming rocks were also revealed. Differences in soil carbon stocks in forests belonging to the same functional type, but formed at different locations in the geochemically linked landscape, have been confirmed: soil carbon stocks were higher in forests at the transit landscapes compared to those in autonomous ones.

Towards talent inclusion: The ecological ground of performance and potentiality – comment on McAuley et al.

From a scientific perspective, talent inclusion for the purposes of development is the most promising path for the use of genetic testing, requiring an enhanced scientific literacy of sports organisation decision-makers, making them less vulnerable to the FOMO effect. The mainstream inflated importance of genetic testing exemplifies an organismic asymmetry. Instead, performance and potentiality should be understood at the ecological level, the organism-environment system level of analysis. Commitment to understanding human behaviour at this ecological scale signifies that performance and potential are not properties located within the athlete (e.g., genes, mental representations), nor within the environment. Rather, it implies the coupling of the performers’ unique characteristics throughout development with affordances offered by a performance context.

Different environmental response strategies in sympatric corals from Pacific Islands

Coral reefs are severely threatened by global and local environmental changes. However, susceptibility to perturbations and subsequent mortality varies among coral species. In this study, we tested the contribution of genetic and environmental conditions to coral’s phenotypic response in Pocillopora spp. and Porites spp. sampled together at a large ecological and temporal scale throughout the Pacific Ocean. We assessed coral phenotype signatures using a multi-biomarker approach (animal and symbiont biomasses, protein carbonylation and ubiquitination and total antioxidant capacities). In both genera, we highlighted a strong anticorrelation between the redox state and the animal and symbiont biomasses. In addition, Pocillopora exhibited high phenotypic plasticity, responding to various environmental variables such as temperature, nutrients, phosphate, and carbonate chemistry. In contrast, Porites displayed more robust phenotypes influenced by both genetics and past climate events. In conclusion, co-located coral species display different phenotypic response strategies that are influenced by different environmental conditions.

A synthesis of the risks of marine light pollution across organismal and ecological scales

Abstract Light pollution is a pervasive global stressor to natural systems. However, due to the proximity of human activities along the coasts and open ocean, light is a pervasive yet commonly overlooked pollutant in many marine habitats. There is a well‐developed body of literature on the visual physiology, behaviour and ecology of many marine taxa, and a re‐evaluation of these data can help inform risks of light pollution to impact marine organisms and ecosystems. This paper identifies key knowledge gaps in the study of marine light pollution ecology and recommends research and management foci for future study. Most work on this pollutant has focused on terrestrial ecosystems and taxa, where experts have learned how anthropogenic light influences behaviour, reproduction cycles and population dynamics. However, light pollution bleeds far beyond the shores, affecting many sensitive ecosystems with light available at unnatural times with varied makeup, such as varying intensities or spectra. This review discusses the current understanding of light dynamics underwater, photoreceptive systems of marine taxa and the documented ecological impacts. This lends a critical basis of understanding for the many gaps in marine light pollution biology. For example, little is known about effects of light on broad groups of marine taxa such as cetaceans, ecosystem‐level effects, or interactive impacts of light and other anthropogenic stressors. Light is a key structuring factor of the marine environment and can therefore elicit immense downstream effects on marine organisms individually, at the population‐ or ecosystem‐level. Light pollution is an urgent concern for marine ecosystems because marine organisms have tight relationships with their natural light environment. As the world moves deeper into the Anthropocene, assessing and mitigating the risks of this pollutant to key environmental and economic marine systems is critical to maintaining a healthy ocean.

Citizen’s Perception on Eco-friendly Lifestyle for Conserving Endangered Oriental White Stork and Crested Ibis Bird Species in Japan – Case Studies in Toyoka, Sado and Konosu Cities

This study aims to find out the relationship between an eco-friendly lifestyle and the attitude towards conservation of endangered Oriental White Stork and Japanese Crested Ibis bird species in Toyooka, Sado, and Konosu cities in Japan. Citizens were surveyed to assess their willingness to spend an eco-friendly lifestyle to protect the above-mentioned endangered bird species through questionnaire surveys. Ecological Mind Evaluation Scale (EM Evaluation scale) developed by Tanaka and Joh (2012) based on Hirose model and Bandura’s research on Self Efficacy was applied in this research. This Ecological Mind Evaluation Scale includes 10 factors and it was applied to develop the questionnaire survey. The factor analysis was undertaken based on 4 groups of questionnaire results; environmental awareness, attitude towards environmental conservation, environmental consciousness and self-efficacy. Factor analysis was performed using the varimax method and sample data set comprised 686 valid responses from the three study sites. The KMO values were over 0.80 indicating the sampling was adequate. According to the factor analysis Sado city scored high for environmental awareness and environment consciousness. Toyooka city scored high on self-efficacy and environmental consciousness. Konosu city was compared with the Toyooka and Sado cities, where more advanced habitat conservation activities are already implemented. Findings displayed that the citizens in Konosu city had low awareness about these bird conservation activities, however, they are willing to contribute in such activities in the future. Thus, this study demonstrated that by engaging in environmentally friendly lifestyles, the citizens can contribute to habitat conservation of endangered bird species

Ecological Stoichiometry of N and P across a Chronosequence of Chinese Fir Plantation Forests

Ecological stoichiometry is crucial in understanding nutrient dynamics and its impact on plant growth and development at various ecological scales. Among the different nutrients, nitrogen (N) and phosphorus (P) have been widely recognized as key elements regulating substance transport, energy utilization, and ecosystem conversion. The N:P ratio in plants serves as a sensitive indicator of ecological processes, reflecting the availability and balance of these nutrients. Therefore, studying the ecological stoichiometry of N and P is essential for accurately assessing soil fertility and site productivity, particularly in forest ecosystems with low-fertility soils. In this study conducted in Huitong, Hunan province, southern China, the contents of N and P, as well as the N:P ratios, were investigated in plant-soil systems across four different aged stands of Chinese fir forests (3-, 8-, 18-, and 26-year-old stands). The results revealed varying concentrations of N and P in soils and foliage across the different plantations. Soil N concentrations increased by approximately 4%, 30%, and 22% in 8-, 18-, and 26-year-old plantations compared to the 3-year-old plantation. Soil P concentration was significantly higher in 8-, 18-, and 26-year-old plantations compared to the 3-year-old plantation. The average soil N:P ratio followed the order of 3-year-old plantation &gt; 18-year-old plantation &gt; 26-year-old plantation &gt; 8-year-old plantation. Regarding foliage, both N and P contents exhibited a similar pattern across the different aged leaves, with current-year-old leaves having higher concentrations than 1-year-old, 2-year-old, and 3-year-old leaves in all four Chinese fir plantations. The study further established relationships between soil and foliage nutrient ratios. Soil N:P ratio was positively correlated with soil N content but negatively associated with soil P content. The foliage N:P ratio also showed a significant negative correlation between leaf N and foliage P content. These findings suggest that soil nutrient conditions improved with the aging of Chinese fir plantations, mainly due to increased inputs of above- and below-ground litter. Overall, this study provides valuable insights into the ecological stoichiometry of N and P in Chinese fir plantations, offering a scientific basis for sustainable forest management practices in southern China.

Revisiting scale invariance and scaling in ecology: River fractals as an example

AbstractScale invariance, which refers to the preservation of geometric properties regardless of observation scale, is a prevalent phenomenon in ecological systems. This concept is closely associated with fractals, and river networks serve as prime examples of fractal systems. Quantifying river network complexity is crucial for unveiling the role of river fractals in riverine ecological dynamics, and researchers have used a metric of “branching probability” to do so. Previous studies showed that this metric reflects the fractal nature of river networks. However, a recent article by Carraro and Altermatt (2022) contradicted this classical observation and concluded that branching probability is “scale dependent.” I dispute this claim and argue that their major conclusion is derived merely from their misconception of scale invariance. Their analysis in the original article (fig. 3a) provided evidence that branching probability is scale‐invariant (i.e., branching probability exhibits a power‐law scaling), although the authors erroneously interpreted this result as a sign of scale dependence. In this article, I re‐introduce the definition of scale invariance and show that branching probability meets this definition. This provided an opportunity to address the divergent use of “scale invariance” and “scaling” between fractal theory and ecology.

Response of total belowground soil biota in Alhagi sparsifolia monoculture at different soil vertical profiles in desert ecosystem

The soil organisms are extremely important for the land-based ecosystem. There is a growing interest in studying the variety and composition of the entire underground soil organism community at a large ecological scale. Soil organisms show different patterns in relation to soil physiochemical properties (SPPs) in various ecosystems. However, there is limited knowledge regarding their response to soil vertical profiles (SVPs) in monoculture of Alhagi sparsifolia, which is the primary shrub in the deserts of China, and is well-known for its contributions to sand dune stabilization, traditional Chinese medicine, and forage. Here, we investigated the population dynamics of soil bacteria, fungi, archaea, protists and metazoa across six different SVPs ranging from 0 to 100 cm in monoculture of A. sparsifolia, in its natural desert ecosystem. Our findings indicate that the soil biota communities displayed a declining pattern in the alpha diversity of bacteria, protists, and metazoa with an increase in soil depth. However, the opposite trend was observed for fungi and archaea. The beta diversity of soil biota was significantly affected by SVPs, particularly for metazoa, fungi and protists as revealed by Non-Metric Dimensional Scaling. The most prevalent soil bacterial, fungal, archaeal, protist, and metazoa classes were Actinobacteria, Sordariomycetes, Nitrososphaeria, Filosa-Sarcomonadea, and Nematoda, respectively. The correlation among vertical distribution of the most abundant biotic communities and variations in SPPs exhibited that the variations in total carbon (TC) and total nitrogen (TN) had the most significant influence on bacterial changes, while available potassium (AK) had an impact on fungi. Archaea were affected by TC and pH, protists by the C/N-Ratio and TP, and metazoa by TN, AK, and soil water capacity (SWC). Collectively, our findings provide a new perspective on the vertical distribution and distinct response patterns of soil biota in A. sparsifolia monoculture under natural desert ecosystem of China.