Ecological Challenges Research Articles

The Hierarchical Coevolutionary Units of Ecological Networks.

In ecological networks, cohesive groups of species may shape the evolution of interactions, serving as coevolutionary units. Ranging across network scales, from motifs to isolated components, elucidating which cohesive groups are more determinant for coevolution remains a challenge in ecology. We address this challenge by integrating 376 empirical mutualistic and antagonistic networks and coevolutionary models. We identified cohesive groups at four network scales containing a significant proportion of potential direct coevolutionary effects. Cohesive groups displayed hierarchical organisation, and potential coevolutionary effects overflowing lower-scale groups were contained by higher-scale groups, underscoring the hierarchy's impact. However, indirect coevolutionary effects blurred group boundaries and hierarchy, particularly under strong selection from ecological interactions. Thus, under strong selection, indirect effects render networks themselves, and not cohesive groups, as the likely coevolutionary units of ecological systems. We hypothesise hierarchical cohesive groups to also shape how other forms of direct and indirect effects propagate in ecological systems.

Care, nature and heritage: shared care practices and thinking

Essentially based on the domination of nature, Western progress has proved as much a source of material comfort and increased life expectancy as it has been destructive and unequal. Ecological collapse and health challenges compel us to mobilize more holistic approaches to care, integrating patients and caregivers, nature and the environment as partners. As a shared function, care can be understood as a founding democratic principle.

Environmental constraints can explain clutch size differences between urban and forest blue tits: Insights from an egg removal experiment.

Urban environments present novel ecological challenges to wild species. In birds, urban populations generally exhibit reduced clutch sizes compared to forest populations. However, whether smaller urban clutches are adaptive or a result of environmental constraints is unclear. To investigate these two hypotheses, we quantified the ability of urban and non-urban blue tits (Cyanistes caeruleus) to lay new eggs after an experimental manipulation aimed to increase egg production. We removed the first four eggs laid by urban and forest birds to test their ability to produce new eggs. If the urban environment imposes constraints on egg production, we predicted that urban birds would not lay new eggs. If the small clutches of urban birds are an adaptive response, we predicted they would lay new eggs to reach the optimal clutch size for the environment. Consistent with the environmental constraint hypothesis, our results suggest that urban females do not lay new eggs to the same extent as forest birds following egg removal. Forest birds laid approximately two new eggs after our experimental manipulation, while urban birds laid approximately 0.36 new eggs following egg removal. Our manipulation resulted in a brood reduction in the urban experimental nests, yet there was no difference in the number of fledged offspring between urban control and experimental nests. This suggests that females might be misjudging urban habitat quality and produce a clutch with more eggs than nestlings they can rear. Overall, our results suggest that environmental constraints could limit the number of eggs that urban females lay, generating urban versus non-urban differences in this trait.

The impact of Artificial Light at Night (ALAN) on biodiversity: flora and fauna at Kebun Raya Bogor

Background: Artificial light at night (ALAN) poses significant ecological challenges by altering the natural light environment. Plants and animals have evolved to depend on natural light cycles for their physiological and behavioral processes. This study investigates the impact of ALAN on the biodiversity of flora and fauna at Kebun Raya Bogor (KRB), a key site for understanding these effects. Methods: This research employs a literature review approach to analyze the effects of ALAN on flora and fauna. By examining existing studies and data, the review focuses on changes in plant physiology, including photosynthesis and growth patterns, as well as alterations in animal behavior, such as foraging, mating, and migration. The review synthesizes findings from various sources to assess the impact of ALAN on biodiversity at KRB. Results: Findings indicate that ALAN disrupts plant photosynthesis and growth, particularly affecting deciduous trees and altering reproductive and growth patterns. For fauna, ALAN significantly impacts the behavior of nocturnal species such as bats and birds, affecting their feeding, mating, and migratory patterns. The disruption in natural light cycles due to ALAN leads to ecological imbalances and may compromise the biodiversity of KRB.

Altitude is correlated with body size differences among Cotesia flavipes (Hymenoptera: Braconidae) wasps collected in two mountain ranges

Living at high altitudes impose physiological and ecological challenges to which species may respond altering their body size, body proportions, and the shape of their body parts. Despite the importance of this topic for understanding the origin of species diversity, little attention has been invested in this phenomenon at the populational level. This paper study the relationship between altitude and body size, body proportions, and forewing shape venation of two populations of the parasitoid wasp Cotesia flavipes. Wasps were collected from Diatraea spp. larvae from sugarcane crops in two Colombian mountain ranges that cover between 600 m and 2143 m of altitude. Linear measurements of different body regions and geometric morphometrics of the forewing were subject to multivariate comparisons and allometric analyses to assess variation and to compare trends between ranges. Central (600 m to 1704 m) and Eastern Cordillera (877 m to 2143 m) populations showed different trends between body size and altitude. Allometric trends were not uniform within or between populations nor between structures. The allometric slopes of five body measurements from a single altitude differed from these from its own mountain range suggesting that body size trends along the cordilleras are a consequence of altitude and not of intrinsic body resource allocation processes. Wing shape between populations differed; however, these changes were poorly related to altitude. In agreement with recent studies in other groups, the observed allometric and wing shape differences between the two C. flavipes populations could be a plasticity response to altitude with interesting implications for posterior genetic differentiation.

Planning for Introducing Electric Buses Based on Ecological and Financial Impacts

The transition from fossil fuel-powered buses to electric buses has emerged as a central concern in recent years. Governments worldwide are urging this shift in major urban centers as a strategic response to ecological challenges, particularly issues related to pollution and carbon emissions. The primary impediment to the electrification transition lies in real-world financial constraints. Consequently, comprehending both the ecological benefits and financial intricacies of transitioning bus fleets is paramount.In the initial section of this paper, we formulate a mathematical model to assess the reduction in carbon emissions and pollution resulting from a complete transition of the bus fleet. This model is then applied to the city of Sendai, Japan. By comparing the carbon dioxide and emission gases released by conventional buses with those emitted by electric buses, we can discern the impact of employing electric buses on the urban ecological environment.Moving on to the second section, we present a mathematical model delineating the financial aspects of the transition. We use Sendai as a real-world exemplar for our model. The economic model is categorized into expenditures and revenues. Expenditures encompass the acquisition of electric buses, maintenance costs, and carbon taxes. On the income side, we consider bus fares, revenue from bus advertising, the budget of the bus company, and government subsidies. By subtracting expenditures from revenues, we can ascertain the financial ramifications of transitioning to electric buses.Following the evaluation from both ecological and financial perspectives of the bus fleet's electric transition, a third model is constructed mathematically to address the optimal planning solution for a city aiming to fully electrify its bus fleet within a decade. The objective is to achieve cost-efficiency: to be the most economical while meeting ecological goals. Finally, the cities of Sendai, Kunshan, and Nashville serve as subjects for our model, each providing a tailored solution to the transition planning.

Understanding the transitional phase of nitrate removal in three different specialty adsorbents for stormwater treatment

Excess nitrogen input from nonpoint sources driven by hydrologic and anthropogenic disturbances has become a significant ecological challenge in receiving water bodies. Moreover, nitrate removal by cost-effective filtration media has still not performed up to expectation because of the knowledge gap in the transitional phase from physicochemical to microbiological processes. This study developed three cost-effective, sustainable, and adaptable green sorption media (GSM), namely CPS (clay–perlite with sand sorption media), ZIPGEM (zero-valent iron and perlite green environmental media), and BIPGEM (biochar, zero-valent iron, and perlite-based green environmental media), made of readily available and recyclable materials, to compare nitrate removal methods for stormwater treatment and elucidate the transitional phase. The primary adsorption mechanism was chemisorption, and subsequent biofilm growth sustained removal efficiency for a long-lasting period. Adsorption kinetics, adsorption equilibrium, material characterization, and fixed-bed column experiments with a 2-stage cultivation approach were undertaken to characterize the transitional phase in these GSM, based on breakthrough curves, maximum adsorption capacity, and microbial population dynamics for nitrification and denitrification. As shown in the column study, BIPGEM had the highest adsorption capacity (7.637 mg∙g−1), followed by ZIPGEM (2.16 mg∙g−1), and CPS (0.1798mg∙g−1). The biochar in BIPGEM provides a better cultivation environment for nitrifying and denitrifying bacteria, contributing sufficient electron donors. Biofilm production and maturation enabled the BIPGEM to maintain 30 % nitrate removal in a steady state even after 2000 h of operation in the first stage. When the biofilm reached maturation, BIPGEM’s nitrate removal percentage was up to 70 % via denitrification in the second stage.

Wujud Pelestarian Lingkungan Melalui Penyuluhan Pembuatan Produk Totebag Ecoprint pada Siswa Sekolah Dasar Negeri Kedung Peluk 1

Environmental education has become increasingly important in addressing global ecological challenges. This community service project aimed to cultivate environmental consciousness among elementary school students through the creative technique of ecoprinting. By using natural materials like leaves and flowers to create unique patterns on fabric, students were not only introduced to an artistic process but also gained a deeper appreciation for the natural world. A workshop was conducted at SDN Kedungpeluk 1 Candi Sidoarjo to teach students the basics of ecoprinting. Participants collected natural materials from their surroundings and experimented with various techniques to create personalized tote bags. The results were impressive, showcasing the students' creativity and their ability to transform natural elements into beautiful and functional objects. Beyond the artistic aspect, the project successfully fostered a sense of environmental stewardship among the students.

International Legal Regulation and Management of Space Waste on Celestial Bodies

The present article explores the international legal regulation of space waste on celestial bodies and the ecological challenges that space missions will pose in the near future. The lack of a shared vision of whether space waste production should be minimized on celestial bodies is causing uncertainty in the planning of future space missions. Leading private space companies are proposing the transfer of dangerous space waste produced from Earth into outer space. The excessive generation of space waste would increase the risks of activities such as space tourism, and space research and will threaten scientific fields such as radio astronomy. The political alliances that exclude a priori third parties will increase the risk of a generation of unnecessary orbital space debris and space waste on celestial bodies because of the development of several space missions in the same field. The sustainability of space missions on celestial bodies and the protection of the outer space environment should become a guiding principle for both national and international legal regulation of space activities. This article argues for the urgent need to establish comprehensive international regulations and monitoring mechanisms to manage space waste on celestial bodies, emphasizing sustainability and cooperation among space-faring nations.

Causal feedback loops modify lake chlorophyll a–nutrient relationships over two decades of nutrient reductions and climate warming

AbstractUnderstanding how the causal feedback between phytoplankton and environmental drivers controlling the chlorophyll a (Chl a, as a proxy of phytoplankton biomass)–nutrient relationships are modulated under different ecosystem conditions is a major challenge in aquatic ecology. Using an empirical dynamic model (convergent cross mapping) on a 20‐yr dataset on 20 Danish lakes, we quantified hypothesized causal feedback networks for each lake and related them to lake system properties (e.g., mean water depth, nutrient concentrations and extent of reduction, climate warming) vs. the Chl a–nutrient relationship (estimated from generalized least square models). The results showed prevalent causal feedback across the studied lakes, which demonstrated clear patterns for the tested ecosystem variations. Weaker causal feedbacks were found in deeper lakes and lakes with larger warming trends, while stronger causal feedbacks appeared in lakes experiencing greater reductions of TP (total phosphorus) and TN (total nitrogen). Moreover, these causal feedbacks showed a strong and positive coupled pattern. Most of the causal feedbacks worked as enhancement loops, which promote the sensitivity of phytoplankton to TP, not least in shallow lakes with a high TP reduction, and as regulatory loops, which force a shift in the Chl a–TN relationship from a more negative slope in lakes experiencing a high nutrient reduction and weak warming to a positive slope in lakes with low nutrient reduction and stronger warming. Our findings suggest a mechanistic explanation of how internal feedbacks regulate the Chl a–nutrient relationships across a broad gradient of nutrient reductions, climate warming, and lake morphologies.

Bridging the ecological–economic–social nexus: sustainability in radioactive waste management

Safe deep geological disposal of radioactive waste is a socio-technical endeavour and connects to different aspects of sustainability. Compared to other long-term infrastructure projects it is unique in terms of time and scope. It affects long temporal dimensions, has an impact on diverse ecological and economic resources, and involves different stakeholder groups. Waste management organizations (WMOs) tasked with the implementation of radioactive waste disposal have to respect these sustainability aspects and meet the respective challenges. This paper provides an introduction to the concept of sustainability and a general overview of the ecological, economic and social challenges and related initial approaches and strategies for the WMOs of deep geological disposal of radioactive waste. With a literature review, sustainability programmes of selected European WMOs are analysed to identify which approaches are being implemented to tackle the various challenges. The various approaches and measures illustrate the broad scope of sustainability in the geological disposal of radioactive waste. Corresponding activities combining technical and non-technical aspects need to be regularly reviewed and adapted to current circumstances and requirements. Differences in the approaches can be explained by differences in the implementation in terms of procedure and time. It is concluded that there is no silver bullet.

Enhancing ecological connectivity in the Qilian Mountains: Integrating GCA and optimized MST models for ecological corridor construction

Amidst global climate change and increased anthropogenic activities, the Qilian Mountains face critical ecological and environmental challenges, including vegetation degradation and declining carbon stocks. Therefore, effective mitigation strategies are critical to building China’s ecological security and enhancing carbon storage. This study constructed and optimized an ecological corridor in the Qilian Mountains using models, such as minimum spanning tree and carbon stock calculation. It combined geographic meta cellular automata and other methods to model ecological recovery in the Qilian Mountains following corridor construction and investigated the areas of particular concern. The results show that: (1) the distribution of the 118 extracted ecological source sites (2020) exhibited a pattern of “dense in the east and sparse in the west.” Compared with the results of the 2010 extraction, the source site area had shrunk by 0.87 % and number of sites had increased by 45.68 %. This implies that the shrinkage and fragmentation of source sites are still increasing, underscoring the urgent need for ecological corridors. (2) Compared to the pre-optimization period, the network node connectivity of the corridor network formed by the optimized 114 primary corridors and 131 secondary corridors has increased by 110 % and the network connectivity has increased by 112 %, which enhances the connectivity of the corridors. (3) From 2000 to 2020, the carbon stock in the Qilian Mountains decreased and then increased; with the construction of a corridor mountain range, the carbon stock can be further increased by 1.4748 million tons. Additionally, the Geographic Cellular Automata (GCA) model simulated that in 2030, the area of forest land in the Qilian Mountains, area of grassland, and carbon stock will increase by 71.75 km2, 313.87 km2, and 6.663 million tons, respectively. These results confirm that ecological protection and corridor construction promote ecological restoration and enhance carbon stocks in the Qilian Mountains, providing a scientific basis for future ecological projects and carbon stock analysis in the region.

Using joint species distribution modelling to identify climatic and non‐climatic drivers of Afrotropical ungulate distributions

The relative importance of the different processes that determine the distribution of species and the assembly of communities is a key question in ecology. The distribution of any individual species is affected by a wide range of environmental variables as well as through interactions with other species; the resulting distributions determine the pool of species available to form local communities at fine spatial scales. A challenge in community ecology is that these interactions (e.g. competition, facilitation, etc.) often are not directly measurable. Here, we used hierarchical modelling of species communities (HMSC), a recently developed framework for joint species distribution modelling, to estimate the role of biotic effects alongside environmental factors using latent variables. We investigate the role of these factors determining species distributions in communities of Artiodactyla, Perissodactyla and Proboscidea in the Afrotropics, an area of peak species richness for hoofed mammals. We also calculate pairwise trait dissimilarity between these species, from a mixture of morphological and behavioural traits, and investigate the relationship between dissimilarity and estimated residual co‐occurrence in the model. We find that while ungulate distributions appear to be predominantly determined (~ 70%) by climatic variables, such as precipitation, a substantial proportion of the variance in ungulate species distributions (~ 30%) can also be attributed to modelled latent variables that likely represent a combination of dispersal barriers and biotic factors. Although we find only a weak relationship between residual co‐occurrence and trait dissimilarity, we suggest that our results may show evidence that biotic factors, likely influenced by historical barriers to species dispersal, are important in determining species communities over a continental area. The HMSC framework can be used to provide insight into factors affecting community assembly at broad scales, and to make more powerful predictions about future species distributions as we enter an era of increasing impacts from anthropogenic change.

Degradable living plastics programmed by engineered spores.

Plastics are widely used materials that pose an ecological challenge because their wastes are difficult to degrade. Embedding enzymes and biomachinery within polymers could enable the biodegradation and disposal of plastics. However, enzymes rarely function under conditions suitable for polymer processing. Here, we report degradable living plastics by harnessing synthetic biology and polymer engineering. We engineered Bacillus subtilis spores harboring the gene circuit for the xylose-inducible secretory expression of Burkholderia cepacia lipase (BC-lipase). The spores that were resilient to stresses during material processing were mixed with poly(caprolactone) to produce living plastics in various formats. Spore incorporation did not compromise the physical properties of the materials. Spore recovery was triggered by eroding the plastic surface, after which the BC-lipase released by the germinated cells caused near-complete depolymerization of the polymer matrix. This study showcases a method for fabricating green plastics that can function when the spores are latent and decay when the spores are activated and sheds light on the development of materials for sustainability.

Does the nexus of corporate social responsibility and green dynamic capabilities drive firms toward green technological innovation? The moderating role of green transformational leadership

Dynamic organizations actively capitalize on social responsibility (CSR) and environmental recovery strategies, considering social and ecological challenges. However, how CSR-committed firms respond to changing environmental technologies and sense critical social and environmental trends is unknown. This study examines the role of CSR in developing green dynamic capabilities (GDC) of organizations, including resource reconfiguration, integration, and environmental insight capabilities, and it explains whether they strengthen organizational green technological innovation (GTI) performance. Specifically, it takes green transformational leadership (GTL) as the moderating variable in the relationship between GDC and GTI. The data collected from 295 manufacturing managers analyzed through linear regression and structural equation modeling indicated that CSR-committed firms have significant capability to integrate and reconfigure green resources and environment insight capability, leading toward improved GTI. The study establishes that GTL bolsters the relationship between resource integration and environmental insights aspects of GDC and GTI; while insignificant relationship exists for resource reconfiguration. Considering their pivotal green transformative role, it suggests that organizational leaders should prioritize sustainability, inspire vision, empower employees, and foster a culture of innovation to leverage the organizational GDC to boost GTI and concludes with policy implications.

Catalyst free PET and PEF polyesters using a new traceless oxalate chain extender.

Plastic material performance is strongly correlated to the polymer's molecular weight. Obtaining a sufficiently high molecular weight is therefore a key goal of polymerization processes. The most important polyester polyethylene terephthalate (PET) and the new polyethylene furanoate (PEF) require metal catalysts and time-consuming production processes to reach sufficiently high molecular weights. Metal catalysts, which are typically antimony or tin for polyesters, end up in the plastic products which may result in sustainability and ecological challenges. When the less reactive comonomer isosorbide is introduced to produce (partly) biobased materials with enhanced thermal properties, such as polyethylene-co-isosorbide furanoate (PEIF), reaching high enough molecular weight becomes even more challenging. This study presents an easily implementable approach to produce high molecular weight PET and PEF polyesters and their isosorbide copolyesters PEIT and PEIF by coupling lower molecular weight polymer chains by the reactive diguaiacyl oxalate (DGO) chain extender. DGO is so reactive, that the use of metal catalysts can be completely avoided and it helps avoiding an extra solid-state polymerization step. In addition, DGO distinguishes itself from typical chain extenders by its ability to be completely removed from the resulting polymer, thereby avoiding the inherent drawbacks associated with typical chain extenders.

Microstructure evolution and mechanical behavior of foamed cement-based tail backfills under varying fiber types and concentrations.

Industrial solid waste (mine tailings) management has emerged as the key universal ecological challenge as a result of the unceasing creation of rising waste by-products. Employing tailings makes mine fill production economical and assists resolve disposal problems. Foamed cement-based tailings backfill (FCTB) is a mine fill consisting of tailing, cement, water, and foaming agents. It provides certain advantages such as lightweight, good fluidity, and thermal insulation yet is relatively weak in strength. Additionally, FCTB's strength properties can be intensely improved by adding fibers. A total of three diverse fibers: polypropylene (PP), glass (G), and basalt (B) as well as dodecyltrimethylammonium bromide (DTAB) as a foaming agent were used to prepare fiber-reinforced foamed cementitious tailings backfill (FR-FCTB). The mechanical properties, energy evolution, ductility, and microstructure of FR-FCTB were elaborately investigated by uniaxial compression tests (UCS) and SEM. Laboratory findings demonstrate the reinforcing effect of three fibers on FCTB specimens: glass > polypropylene > basalt. FR-FCTB showed the best strength features as a fiber content of 0.3% was adopted in FCTB. At this time, the UCS performance of glass fiber-reinforced FCTBs was 0.85MPa increased by 18.1%. The addition of fibers can increase the fill's energy storage limit, slow down the discharge of elastic strain energy within the backfill, and enhance the fill's ductility and toughness. The ductility factor evaluates the degree of deterioration of filling in terms of post-peak drop, with all FR-FCTB values being greater than CTB. FR-FCTB's chief hydration product is the C-S-H gel. Fiber's bridging effect significantly rallies crack extension and thus fill's strength features. Lastly, the study's main results are instructive for the industrial application of FR-FCTB used in metallic mines.

Xerogel mesoporous materials based on ultrastable Blatter radicals for efficient sorption of nitric oxide

The reduction of hazardous nitric oxide emissions remains a significant ecological challenge. Despite the variety of possibilities, sorbents able to capture low concentrations of NO from flue gas with high selectivity are still in demand. In this work a new type of mesoporous xerogel material highly loaded with ultrastable Blatter radicals (BTR, >60 % by mass) that act as selective NO sorption sites is developed. Electron Paramagnetic Resonance (EPR) spectroscopy evidences reversible NO sorption in nanometer-scale pores of BTR-based xerogels and indicates the high NO capacity of such radical-rich sorbent. Efficient NO capture from model flue gas mixture is also evidenced in experiments with a fixed bed reactor. Such advanced properties of new materials as selectivity, strong binding with NO and an ability for mild regeneration via thermodesorption promote them for future ecological applications.

Climate-driven environmental filtering determines hump-shaped elevational pattern of seed plant beta diversity in the central Himalayas

Understanding how and why assemblage dissimilarity changes along spatial gradient is a great challenge in ecology, because answers to these questions depend on the analytical types, dimensions, and components of beta diversity we concerned. To obtain a comprehensive understanding of assemblage dissimilarity and its implications for biodiversity conservation in the Himalayas, we explored the elevational patterns and determinants of beta diversity and its turnover and nestedness components of pairwise and multiple types and taxonomic and phylogenetic dimensions simultaneously. Patterns of beta diversity and their components of different types and dimensions were calculated based on 96 sampling quadrats along an 1800−5400 m elevational gradient. We examined whether and how these patterns differed from random expectations using null models. Furthermore, we used random forest methods to quantify the role of environmental variables representing climate, topography, and human disturbance in determining these patterns. We found that beta diversity and its turnover component, regardless of its types and dimensions, shown a hump-shaped elevational patterns. Both pairwise and multiple phylogenetic beta diversity were remarkably lower than their taxonomic counterpart. These patterns were significantly less than random expectation and were mostly associated with climate variables. In summary, our results suggested that assemblage dissimilarity of seed plants was mostly originate from the replacement of closely related species determined by climate-driven environmental filtering. Accordingly, conservation efforts should better cover elevations with different climate types to maximalize biodiversity conservation, rather than only focus on elevations with highest species richness. Our study demonstrated that comparisons of beta diversity of different types, dimensions, and components could be conductive to consensus on the origin and mechanism of assemblage dissimilarity.

Meta-analytical evidence for frequency-dependent selection across the tree of life.

Explaining the maintenance of genetic variation in fitness-related traits within populations is a fundamental challenge in ecology and evolutionary biology. Frequency-dependent selection (FDS) is one mechanism that can maintain such variation, especially when selection favours rare variants (negative FDS). However, our general knowledge about the occurrence of FDS, its strength and direction remain fragmented, limiting general inferences about this important evolutionary process. We systematically reviewed the published literature on FDS and assembled a database of 747 effect sizes from 101 studies to analyse the occurrence, strength, and direction of FDS, and the factors that could explain heterogeneity in FDS. Using a meta-analysis, we found that overall, FDS is more commonly negative, although not significantly when accounting for phylogeny. An analysis of absolute values of effect sizes, however, revealed the widespread occurrence of modest FDS. However, negative FDS was only significant in laboratory experiments and non-significant in mesocosms and field-based studies. Moreover, negative FDS was stronger in studies measuring fecundity and involving resource competition over studies using other fitness components or focused on other ecological interactions. Our study unveils key general patterns of FDS and points in future promising research directions that can help us understand a long-standing fundamental problem in evolutionary biology and its consequences for demography and ecological dynamics.