Hasil untuk "Ecology"

R. O'Neill

D. Hillel, J. Hatfield

Huma Ali, Muhammad Rafiq, Muhammad Manzoor et al.

Abstract Background The western Himalayan forest ecosystem faces escalating pressures from climate change and anthropogenic activities, demanding improved conservation strategies. Effective management requires understanding the seasonal fluctuations in vegetation, soil properties and microbial communities, but they remain poorly characterized across high altitude forests. We assessed these variables in 10 forest sites during the winter of 2023 and summer of 2024, analysing vegetation diversity, soil parameters, and microbial metagenomics. Results We found pronounced seasonal shifts in plant and microbial diversities, and in soil properties. Plant species richness, and Shannon and Simpson diversity indices were higher (p < 0.001) in summer than in winter while the community maturity index was higher (p < 0.02) in winter than in summer. Soil properties exhibited clear seasonal patterns: pH, available phosphorus (AP), microbial biomass carbon (MBC) and cation exchange capacity (CEC) were higher (p < 0.05) in summer, whereas soil moisture (SM) and soil organic carbon (SOC) were higher (p < 0.05) in winter. Microbial alpha diversity indices (Shannon, Chao, and Sobs) were elevated (p < 0.05) in summer, while the Simpson index was elevated in winter, indicating a shift in community dominance. Beta diversity analyses revealed a significant seasonal shift in overall metabolic potential (KEGG orthologs; ANOSIM R = 0.222, p = 0.016), but not in general protein functions (COG), carbohydrate-active enzymes (CAZy), or taxonomic composition (RefSeq). Therefore, despite taxonomic turnover, core metabolic functions were maintained, indicating strong functional redundancy. Structural equation models (SEM) confirmed distinct seasonal dynamics, revealing stronger plant-soil-microbe interactions and a greater proportion of variance explained by the model in summer (R2=0.64–0.72 for key paths) than in winter (R2=0.52–0.63). Conclusions The findings demonstrate that the western Himalayan ecosystem undergoes a fundamental seasonal reorganization. Summer is characterized by increased biodiversity, distinct soil conditions, and more dynamic microbial-ecosystem interactions, while winter exhibits greater community maturity and functional stability. The resilience of core ecosystem processes is underpinned by microbial functional redundancy, which ensures metabolic continuity despite taxonomic shifts. We recommend that forest management strategies account for these seasonal dynamics and focus on preserving the conditions that support this critical functional redundancy.

Roman Shmyh, Taras Shchur, Mustafa B. Dawood et al.

Constructive solutions for tensioned concrete-filled steel tubular (CFST) elements can be applied in bar systems (trusses, arches, frames, structural and cable-stayed structures, radio and television towers, as well as other similar applications) and can be significantly more cost-effective compared to concrete-filled tubes, reinforced concrete, and steel structures. Tensioned CFST elements, in cross-section, consist of a steel shell tube filled with concrete, which is reinforced with either high-strength conventional or high-strength prestressed reinforcement. The load-bearing capacity of a CFST element is determined by the combined strength of the steel tube, the concrete, and the high-strength steel reinforcement bars, all working together as a unified cross-section. It is known that mild steel in the tube, when subjected to tension, is characterized by its yield strength and ultimate strength, while highstrength reinforcement bars are defined by their conditional yield strength and ultimate strength. In experimental tensioned CFST elements, the interaction between the mild steel tube and the high-strength reinforcement steel proves beneficial. This combination allows the mild steel tube to effectively operate beyond its yield limit. When the tube steel reaches its yield point, it temporarily ceases to absorb additional load. At this moment, the increasing load is transferred to the high-strength reinforcement bars, which have not yet reached their conditional yield strength. Regarding the mild steel tube of the tensioned CFST element, it undergoes strain hardening during this phase. Its longitudinal deformations develop in accordance with the deformations of the high-strength reinforcement bars. With further loading, the mild steel tube can bear a portion of the load within the limits of its ultimate strength, which enhances the element’s load-bearing capacity and, consequently, improves the economic efficiency of the structural solution. The aim of this scientific study is to develop a practical algorithm for calculating the load-bearing capacity of tensioned CFST elements.

Yanyan Lyu, Yong Wang, Xiaoling Shen

Global climate change poses a serious threat to <i>Torreya grandis</i>, a rare and economically important tree species, making the accurate mapping of its spatial distribution essential for forest resource management. However, extracting forest-growing areas remains challenging due to the limited spatial and temporal resolution of remote sensing data and the insufficient classification capability of traditional algorithms for complex land cover types. This study utilized monthly Sentinel-2 imagery from 2023 to extract multitemporal spectral bands, vegetation indices, and texture features. Following minimum redundancy maximum relevance (mRMR) feature selection, a spatial–spectral fused attention network (SSFAN) was developed to extract the distribution of <i>T. grandis</i> in the Kuaiji Mountain area and to analyze the influence of topographic factors. Compared with traditional deep learning models such as 2D-CNN, 3D-CNN, and HybridSN, the SSFAN model achieved superior performance, with an overall accuracy of 99.1% and a Kappa coefficient of 0.961. The results indicate that <i>T. grandis</i> is primarily distributed on the western, southern, and southwestern slopes, with higher occurrence at elevations above 500–600 m and on slopes steeper than 20°. The SSFAN model effectively integrates spectral–spatial information and leverages a self-attention mechanism to enhance classification accuracy. Furthermore, this study highlights the joint influence of natural factors and human land-use decisions on the distribution pattern of <i>T. grandis.</i> These findings aid precision planting and resource management while advancing methods for identifying tree species.

Maslim As-singkily, Maslim As-singkily, Maslim As-singkily et al.

Leatherback turtles (Dermochelys coriacea) are highly migratory and globally distributed, yet exhibit low overall genetic diversity. Currently, the species is divided into seven Regional Management Units (RMUs), and significant gaps remain in understanding genetic connectivity within the Indo-Pacific, particularly the Northeast Indian Ocean. Here, we investigate the genetic diversity and population structure of leatherback turtles sampled from five nesting sites in Sumatra, Indonesia. Using mitochondrial DNA (mtDNA) control region sequences from 57 individuals, we identified eight haplotypes, including one novel variant, with Sumatra exhibiting the highest haplotype (h = 0.786) and nucleotide diversity (π = 0.0040) among regional rookeries. There was a lack of significant stock structure based on our haplotype frequency data among rookeries in Sumatra (p&gt;0.05). Phylogenetic and haplotype network analyses revealed that Sumatra contains lineages from both Indian and West Pacific Ocean clades, suggesting its role as a genetic bridge between these populations. Our results on population genetic structure support the recognition of Sumatra as a distinct Management Unit (MU), separate from other Northeast Indian Ocean populations. Our findings highlight the need to refine existing RMU boundaries and prioritize conservation actions in Sumatra to preserve its unique genetic composition and enhance connectivity across the Indo-Pacific.

Benji Zhou, Nengneng Xu, Liangcai Wu et al.

Fabricating non-noble metal-based carbon air electrodes with highly efficient bifunctionality is big challenge owing to the sluggish kinetics of oxygen reduction/evolution reaction (ORR/OER). The efficient cathode catalyst is urgently needed to further improve the performance of rechargeable zinc-air batteries. Herein, an activation-doping assisted interface modification strategy is demonstrated based on freestanding integrated carbon composite (CoNiLDH@NPC) composed of wood-based N and P doped active carbon (NPC) and CoNi layer double hydroxides (CoNiLDH). In the light of its large specific surface area and unique defective structure, CoNiLDH@NPC with strong interface-coupling effect in 2D-3D micro-nanostructure exhibits outstanding bifunctionality. Such carbon composites show half-wave potential of 0.85 V for ORR, overpotential of 320 mV with current density of 10 mA cm−2 for OER, and ultra-low gap of 0.70 V. Furthermore, highly-ordered open channels of wood provide enormous space to form abundant triple-phase boundary for accelerating the catalytic process. Consequently, zinc-air batteries using CoNiLDH@NPC show high power density (aqueous: 263 mW cm−2, quasi-solid-state: 65.8 mW cm−2) and long-term stability (aqueous: 500 h, quasi-solid-state: 120 h). This integrated protocol opens a new avenue for the rational design of efficient freestanding air electrode from biomass resources.

Flavia Virginia Frohlich, Ana Sofía Nanni

El ocelote (Leopardus pardalis) es uno de los 11 felinos presentes en Argentina, y ha sido categorizado como “Vulnerable” (VU), reportando una disminución en sus poblaciones del 25% en la ecorregión Yungas. En este trabajo estimamos la abundancia relativa, densidad, y patrones de actividad del ocelote (Leopardus pardalis) y caracterizamos al ensamble de mamíferos mediano-grandes a lo largo de un gradiente altitudinal (500 a 1400 m s.n.m.) de las Yungas de Tucumán, dentro de en un área protegida privada de 3000 hectáreas. Establecimos 10 sitios de muestreo separados entre sí por 500 a 900 m. En cada sitio ubicamos dos cámaras-trampa enfrentadas para identificar individuos de ocelote a través de marcas distintivas. El esfuerzo de muestreo fue de 1408 días-trampa y registramos 11 especies de mamíferos mediano-grandes (nueve especies nativas y dos exóticas: el perro doméstico y la liebre). La densidad estimada de ocelotes fue de 15,2 ind/100 km2, un valor similar a los obtenidos en la Selva Paranaense de Misiones (17,6 ind/100 km2), el cual requiere un esfuerzo más exhaustivo de muestreo para corroborarse. Este estudio brinda una primera aproximación sobre el estado poblacional del ocelote, y un importante aporte a la línea de base de la Reserva San Pablo.

Håvard Haarstad, Siddharth Sareen, Tarje Iversen Wanvik

Climate-related targets for cities abound, but it is unclear how important they are in driving actual transformations. Scholars have often taken a skeptical view of official climate discourses, including their ambitious targets, and instead turned their attention to experimentation, innovation and civic action – colloquially termed 'real action.' In this article we try on the opposite view. Contributing to 'speculative political ecology', we argue that climate-related targets, even those without hard policies directly attached to them, can render climate change more governable and actionable. In a fragmented, polycentric and dispersed governance landscape, the immutability of a 'hard' number can create coherence, direction and measurability to policy action. We examine a particular target, and its associated governance instruments, which has arguably had a transformative effect on urban policy. Our empirical focus is Norway's Zero Growth Objective in urban transport policy. We follow the target from its first formulation as a soft goal around 2006 and until 2019, by when it had materialized as a hard target shaping funding streams and concrete policy interventions, and most likely, emission levels. Arguably, it has been a highly effective frame for policy.

José Escurra, Francisco P. Ferreira, Tomás R. López et al.

Lactic acid is a compound used industrially due to its properties. There are two methods for its production: chemical synthesis and microbial fermentation. In microbial fermentation, food industry waste can be used as a substrate, providing a route towards achieving a circular economy. Thus, this study evaluated different substrates for <i>Lactobacillus plantarum</i> growth, a lactic acid producer, such as molasses, whey, glucose, and saccharose, either alone or supplemented with additional nutrients. Bacterial growth parameters were assessed using OD₆₂₀ measurement. It was shown that whey supplemented with yeast extract supported the best growth, allowing a μ_max = 0.63 h⁻¹.

G. Bertram

H. S. Horn

Johan Buitendag

I approach this venture of figuring out the correct terminology to understand reality through the prism of two distinctive Russian Orthodox theologians, Pavel Florensky (1882–1937) and Sergius Bulgakov (1871–1944). The lens I apply mainly to their works is their respective understanding of cosmology, that is, ontology and epistemology. Therefore, I concur with Grenz to abandon the term ‘onto-theology’ and qualify the inverse as a Trinitarian theo-ontology. This honours the intimate connection between knowing and being, and prevents the bifurcation between fidelity and rationality. Mutatis mutandis, the same applies to ‘eco-theology’. This inversion reminds one of Hans-Urs von Balthasar, who bartered the concept of an aesthetic theology for theological aesthetics. Turning this question around would advance our dialogue with the sciences as the common denominator of the discourse is rather nature (creation) discerned from an acknowledged a priori (as all cognition do). In other words, the term theo-ecology is proposed. Intradisciplinary and/or interdisciplinary implications: The purpose study is not ecological but rather an asyndetic use of the terminology about the science and religion dialogue, with reference to the nomenclature of ecology and theology. All observation terms and sentences are theory-laden. Religion can be viewed as a linguistic framework that shapes the entirety of life and thought. Truth claims should focus on the grammar (or rules of the game) and not the lexicon when expressive symbolism is employed.

R. B. Payne

J. Stewart, F. E. Round

Fabio Amato

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R. Daubenmire

G. Lucas, D. Ranwell

R. Mulholland, C. M. Gowdy

G. Cox