Search Results (13)

Heavy metal pollution poses a global environmental challenge, with lead (Pb) being particularly concerning due to its persistence and toxicity. This study investigated Xanthium strumarium L. from China’s Yellow River Sanmenxia section through hydroponic experiments (0–600 mg/L Pb²⁺, 1–11 d exposure) to elucidate its Pb²⁺ response mechanisms. Integrated analyses (EDX, FTIR, thermogravimetry, hyperspectral imaging) revealed a three-phase sequestration strategy: the roots immobilized 88.55% of Pb through pectin carboxyl de-esterification and lignin–Pb complexation, while the stems and leaves retained <11.14% and <0.31%, respectively. A critical threshold (300 mg/L) triggered nonlinear Pb accumulation escalation. Thermogravimetric analysis demonstrated enhanced cell wall stability under Pb stress (66.7% residual carbon increase at 600 mg/L). Hyperspectral features (1670 nm band intensity) effectively tracked physiological stress dynamics. The findings establish X. strumarium’s superior suitability for root-based immobilization rather than phytoextraction in Pb-contaminated sites, with its low translocation efficiency minimizing ecological risks. The identified concentration threshold and spectral biomarkers provide multi-scale insights for optimizing in situ phytostabilization strategies, advancing both theoretical understandings and practical applications in heavy metal remediation. Full article

Shallow landslides are often unpredictable and seriously threaten surrounding infrastructure and the ecological environment. Traditional landslide prediction methods are time-consuming, labor-intensive, and inaccurate. Thus, there is an urgent need to enhance predictive techniques. To accurately predict the runout distance of shallow landslides, this study focuses on a shallow soil landslide in Tongnan District, Chongqing Municipality. We employ a genetic algorithm (GA) to identify the most hazardous sliding surface through multi-iteration optimization. We discretize the landslide body into slice units using the dynamic slicing method (DSM) to estimate the runout distance. The model’s effectiveness is evaluated based on the relative errors between predicted and actual values, exploring the effects of soil moisture content and slice number on the kinematic model. The results show that under saturated soil conditions, the GA-identified hazardous sliding surface closely matches the actual surface, with a stability coefficient of 0.9888. As the number of slices increases, velocity fluctuations within the slices become more evident. With 100 slices, the predicted movement time of the Tongnan landslide is 12 s, and the runout distance is 5.91 m, with a relative error of about 7.45%, indicating the model’s reliability. The GA-DSM method proposed in this study improves the accuracy of landslide runout prediction. It supports the setting of appropriate safety distances and the implementation of preventive engineering measures, such as the construction of retaining walls or drainage systems, to minimize the damage caused by landslides. Moreover, the method provides a comprehensive technical framework for monitoring and early warning of similar geological hazards. It can be extended and optimized for all types of landslides under different terrain and geological conditions. It also promotes landslide prediction theory, which is of high application value and significance for practical use. Full article

Calcium (Ca) and Boron (B) are structural components of the cell wall with limited phloem mobility. The absorption, movement, and distribution of these two nutrients have a greater effect on leaves than on fruits since their transport is dependent on transpiration flow. This research aimed to study the absorption and movement of ⁴⁵Ca applied to the soil and the fruit of sweet cherry trees under B-deficient and B-adequate soil conditions. In the first experiment, ⁴⁵Ca was applied to the soil surface before the occurrence of leaf senescence. Soil and tree components were sampled and analyzed 6 months after ⁴⁵Ca application. The second experiment involved a ⁴⁵Ca application to the surface of small fruits with 5 mm diameters, which were analyzed after 45 days. The tree Ca allocation in the B-deficient soil condition was significantly fewer in shoots and higher in roots, contrary to the B-adequate soil. On the other hand, the fruit evidenced significant differences in Ca levels in the edible portion of the fruit (i.e., the flesh and peel), which was higher in the B-adequate soil condition. Therefore, under B-deficient soil, Ca was ‘retained’ in the root system and in the fruit pit, suggesting a synergistic mechanism between Ca and B. This mechanism might indicate a survival ecological function where B triggers biological signals to restore Ca homeostasis. Full article

Urban nature exists in all cities, including spontaneous nature. Spontaneous vegetation has been well-documented in the broader ecological literature in the Northern Hemisphere in recent decades. However, the recognition of, and interest in, spontaneous nature in Australia is limited. Our study initiated research on spontaneous vegetation in Southwest Australia from a landscape architectural site analysis approach with vegetation surveys. This study created an inventory of plants in four biotope types (specific abiotic environments with associated plant communities), i.e., cracks, walls, margins, and vacant lots, in two cities. Twenty-four sites were surveyed four times over a calendar year, and 145 plant species were identified. More than 90% of the species were naturalised, with native ranges most common in the Mediterranean Basin (34 species), and predominantly annuals (73 species). Only eight species were native to Southwest Australia. Our analysis revealed some of the cultural and ecological characteristics of these sites and species, i.e., environmental histories, pollinator habitats, the temporary statuses of sites with spontaneous nature, and their potential, e.g., altering maintenance schedules to retain foraging resources. Therefore, this study recommends further exploration of spontaneous nature through small-scale site analysis approaches and at larger scales for a more detailed understanding of this, at present, overlooked part of nature in Southwest Australian cities. Full article

Global climate change and persistent droughts lead to soil desertification, posing significant challenges to food security. Desertified lands, characterized by high permeability, struggle to retain water, thereby hindering ecological restoration. Sand, a natural resource abundant in deserts, inspired our proposal to design hydrophobic sand and construct Air-permeable Aquicludes (APAC) using this material. This approach aims to address issues related to the ecological restoration of desertified lands, food security, and the utilization of sand resources. Reclamation of desertified land and sandy areas can simultaneously address ecological restoration and ensure food security, with soil reconstruction being a critical step. This study investigated the effects of constructing an Air-permeable Aquiclude (APAC) using hydrophobic sand on rice yield and lodging resistance, using clay aquitard (CAT) and plastic aquiclude (PAC) as control groups. The APAC enhanced soil oxygen content, increased internode strength, and improved vascular bundle density, substantially reducing the lodging index and increasing yield. This research finds that the APAC (a) increased internode outer diameter, wall thickness, fresh weight, and filling degree; (b) enhanced the vascular bundle area by 11.11% to 27.66% and increased density; (c) reduced the lodging index by 37.54% to 36.93% (p < 0.01); and (d) increased yield to 8.09 t·hm⁻², a rise of 12.05% to 14.59% (p < 0.05), showing a negative correlation with lodging index. These findings suggest that APAC has very good potential for desertified land reclamation and food security. In conclusion, the incorporation of hydrophobic sand in APAC construction considerably strengthens rice stem lodging resistance and increases yield, demonstrating considerable application potential for the reclamation of desertified and sandy land and ensuring food security. Full article

Challenges related to sustainability arise in all areas of human activity, but with a significant impact on the environment considering that the construction industry is held accountable for nearly one-third of the world’s final energy consumption. The aim of this paper is to assess through the use of the Bob–Dencsak specific model a sustainable slope design taking into account environmental, economic, and safety variables. Thus, analysis was performed on four intervention works, two versions of reinforced concrete retaining walls and two versions of reinforced soil with a biaxial geogrid, which ensure the stability of a slope that serves as a base for an access road to an ecological landfill located in Alba County, Romania. The study’s analysis points out that reinforced soil retaining walls are far more sustainable, providing the best sustainability indices, which is also supported by the impact of geogrids compared to reinforced concrete, thus resulting in the finding that reinforced concrete is less sustainable, achieving increases of up to 23% for embodied energy and 66% of CO₂ emissions in the atmosphere. Finally, the paper provides recommendations for future research on the sustainability assessment of slopes, with the intention of reducing environmental damage, while keeping costs to a minimum. Full article

As the most common geological disaster problem in mines, slope geological disasters have become a focus of research, along with the difficulty of mine safety and ecological environment protection together with the ecological restoration of open-pit mines. At present, a large number of slope-retaining wall structures lack research on safety monitoring, real-time acquisition, and intelligent early warning. Therefore, this paper combines cement-modified loess with gravity retaining wall structures and puts forward a new type of greening gravity retaining wall structure. From the perspective of “the Internet of Things + construction”, a video monitoring system is established to monitor the retaining wall structure in real time. Finally, based on video image processing technology, the deformation of the retaining wall surface is identified and the inclination angle of the wall surface is calculated, so as to improve the real-time and intelligent monitoring of the new greening gravity retaining wall. The results show that the new greening gravity retaining wall based on video monitoring proposed in this paper has the characteristics of a gravity retaining wall and ecological retaining wall, which are conducive to improving the real-time and intelligent monitoring of the new greening gravity retaining wall. Cement-modified loess is used as the planting matrix, and the cement mixing ratio should not exceed 10%. Considering the requirements of economy and shear strength, the cement mixing ratio should be selected from 5% to 12%. Full article

Carnivorous rainbow plants (Byblis, Byblidaceae, Lamiales) possess sticky flypaper traps for the capture, retention, and digestion of prey (mainly small insects). The trapping system is based on a multitude of millimeter-sized glandular trichomes (also termed stalked glands), which produce adhesive glue drops. For over a century, the trapping system of Byblis was considered passive, meaning that no plant movement is involved. Recently, a remarkable discovery was made: the stalked glands of Byblis are indeed capable of reacting to chemical (protein) stimuli with slow movement responses. This prompted us to investigate this phenomenon further with a series of experiments on the stimulation, kinematics, actuation, and functional morphology of the stalked glands of cultivated Byblis gigantea plants. Measured stalked gland lengths and densities on the trap leaves are similar to the data from the literature. Motion reactions could only be triggered with chemical stimuli, corroborating the prior study on the stalked gland sensitivity. Reaction time (i.e., time from stimulation until the onset of motion) and movement duration are temperature-dependent, which hints towards a tight physiological control of the involved processes. The stalked gland movement, which consist of a sequence of twisting and kinking motions, is rendered possible by the components of the stalk cell wall and is furthermore anatomically and mechanically predetermined by the orientation of cellulose microfibrils in the cell wall. Successive water displacement processes from the stalk cell into the basal cells actuate the movement. The same kinematics could be observed in stalked glands drying in air or submersed in a saturated salt solution. Stimulated and dried stalked glands as well as those from the hypertonic medium were capable of regaining their initial shape by rehydration in water. However, no glue production could be observed afterwards. The long-time overlooked chemonastic movements of stalked glands may help Byblis to retain and digest its prey; however, further research is needed to shed light on the ecological characteristics of the rainbow plant’s trapping system. Full article

Prefabricated walls are frequently utilized as retaining structures in different applications. A new type of prefabricated greening ecological retaining wall (PGERW) is proposed in this research. Full-scale tests and numerical simulations were conducted to investigate the stress characteristics of the PGERW. To this end, the load–stress relationship, load–displacement relationship, and crack development of the retaining wall columns were carefully evaluated. It was found that when the load acting on the 3 m high column reached the ultimate load-bearing capacity (about 150 kN), an “arc + 7”-shaped crack pattern emerged. A V-shaped crack composed of bolt–chamfer cracks formed when the load applied to a 2.5 m high column reached the ultimate load-bearing capacity (about 335 kN). The design of hollow thin-walled columns can effectively reduce the amount of concrete used and, as a consequence, reduce its carbon emissions, while meeting the design strength requirements of the retaining wall. The PGERW addresses the challenges of improving the extent of greening and drainage performance of traditional prefabricated retaining walls. It has excellent applicability to highway slope construction and therefore can be applied in several contexts. Full article

The retaining wall is a common slope protection structure. To tackle the current lack of sustainable and highly prefabricated retaining walls, an environmentally friendly prefabricated ecological grid retaining wall with high construction efficiency has been developed. Due to the asymmetrical condition of the project considered in this paper, the designed prefabricated ecological grid retaining wall was divided into the excavation section and the filling section. By utilizing the ABAQUS finite element software, the stress and deformation characteristics of the retaining wall columns, soil, anchor rods, and inclined shelves in an excavation section, and the force and deformation relationships of the columns, rivets, and inclined shelves in three working conditions in a filling section were studied. The study results imply that the anchor rods may affect the columns in the excavation section and the stress at the column back changes in an M-shape with height. Moreover, the peak appears at the contact point between the column and the anchor rod. The displacement of the column increases slowly along with the height, and the column rotates at its bottom. In the excavation section, the stress of the anchor rod undergoes a change at the junction of the structure. The inclined shelf is an open structure and is very different from the retaining plate structure of traditional pile-slab retaining walls. Its stress distribution follows a repeated U-shaped curve, which is inconsistent with the trend of the traditional soil arching effect between piles, which increases first and then decreases. For the retaining wall structure in the filling section, the numerical simulated vehicle load gives essentially consistent results with the effects of the equivalent filling on the concrete column. Full article

This study describes life cycle assessment (LCA) results of the excavation depth and ground condition of a medium-sized excavation ground in order to examine the effect of construction methods on environmental and economic feasibility for an earth-retaining wall. LCA is conducted in consideration of eight environmental impact categories according to the construction stage of the earth-retaining wall. In addition, the environmental cost of construction method for the earth-retaining wall was calculated, and its selection criteria were analyzed based on the calculation results. The evaluation results of the environmental load of construction methods for the earth-retaining wall show that the H-Pile+Earth plate construction method has low economic efficiency because the construction method significantly increased the environmental load due to the increased ecological toxicity. The environmental load characteristics have a greater effect on the selection of construction methods in sandy soil than in composite soil when the excavation depth is the same. The evaluation result of the environmental cost of the construction methods for the earth-retaining wall shows that the environmental cost increased as the excavation depth increased, and the sandy soil conditions have higher environmental costs than complex soil conditions. Full article

In this study, considering the eco-friendly design necessities of reinforced concrete structures, the acquirement of minimizing both the cost and the CO₂ emission of the reinforced concrete retaining walls in conjunction with ensuring stability conditions has been investigated using harmony search algorithm. Optimization analyses were conducted with the use of two different objective functions to discover the contribution rate of variants to the cost and CO₂ emission individually. Besides this, the integrated relationship of cost and CO₂ emission was also identified by multi-objective analysis in order to identify an eco-friendly and cost-effective design. The height of the stem and the width of the foundation were treated as design variables. Several optimization cases were fictionalized in relation with the change of the depth of excavation, the amount of the surcharge applied at the top of the wall system at the backfill side, the unit weight of the backfill soil, the costs, and CO₂ emission amounts of both the concrete and the reinforcement bars. Consequently, the results of the optimization analyses were arranged to discover the possibility of supplying an eco-friendly design of retaining walls with the minimization of both cost and gas emission depending upon the comparison of outcomes of the identified objective functions. The proposed approach is effective to find both economic and ecological results according to hand calculations and flower pollination algorithm. Full article

Urban water systems face severe challenges such as urbanisation, population growth and climate change. Traditional technical solutions, i.e., pipe-based, grey infrastructure, have a single purpose and are proven to be unsustainable compared to multi-purpose nature-based solutions. Green Infrastructure encompasses on-site stormwater management practices, which, in contrast to the centralised grey infrastructure, are often decentralised. Technologies such as green roofs, walls, trees, infiltration trenches, wetlands, rainwater harvesting and permeable pavements exhibit multi-functionality. They are capable of reducing stormwater runoff, retaining stormwater in the landscape, preserving the natural water balance, enhancing local climate resilience and also delivering ecological, social and community services. Creating multi-functional, multiple-benefit systems, however, also warrants multidisciplinary approaches involving landscape architects, urban planners, engineers and more to successfully create a balance between cities and nature. This Special Issue aims to bridge this multidisciplinary research gap by collecting recent challenges and opportunities from on-site systems up to the watershed scale. Full article