Glacier shrinkage, a notable consequence of climate change, is expected to intensify, particularly in high-elevation areas. While plant diversity and soil microbial communities have been studied, research on soil organic matter (SOM) and soil protein function dynamics in glacier forefields is limited. This limited understanding, especially regarding the link between microbial protein functions and biogeochemical functions, hampers our knowledge of soil-ecosystem processes along chronosequences. This study aims to elucidate the mechanistic relationships among soil bacterial protein functions, SOM decomposition, and environmental factors such as plant density and soil pH to advance understanding of the processes driving ecosystem succession in glacier forefields over time. Proteomic analysis showed that as ecosystems matured, the dominant protein functions transition from primarily managing cellular and physiological processes (biological controllers) to orchestrating broader ecological processes (ecosystem regulators) and increasingly include proteins involved in the degradation and utilization of OM. This shift was driven by plant density and pH, leading to increased ecosystem complexity and stability. Our confirmatory path analysis findings indicate that plant density is the main driver of soil process evolution, with plant colonization directly affecting pH, which in turn influenced nutrient metabolizing protein abundance, and SOM decomposition rate. Nutrient availability was primarily influenced by plant density, nutrient metabolizing proteins, and SOM decomposition, with SOM decomposition increasing with site age. These results underscore the critical role of plant colonization and pH in guiding soil ecosystem trajectories, revealing complex mechanisms and emphasizing the need for ongoing research to understand long-term ecosystem resilience and carbon sequestration.

Surface soil moisture (SSM) is a key limiting factor for vegetation growth in alpine meadow on the Qinghai-Tibetan Plateau (QTP). Patches with various sizes and types may cause the redistribution of SSM by changing soil hydrological processes, and then trigger or accelerate alpine grassland degradation. Therefore, it is vital to understand the effects of patchiness on SSM at multi-scales to provide a reference for alpine grassland restoration. However, there is a lack of direct observational evidence concerning the role of the size and type of patches on SSM, and little is known about the effects of patches pattern on SSM at plot scale. Here, we first measured SSM of typical patches with different sizes and types at patch scale and investigated their patterns and SSM spatial distribution through unmanned aerial vehicle (UAV)-mounted multi-type cameras at plot scale. We then analyzed the role of the size and type of patchiness on SSM at both patch and plot scales. Results showed that: (1) in situ measured SSM of typical patches was significantly different (P < 0.01), original vegetation patch (OV) had the highest SSM, followed by isolate vegetation patch (IV), small bare patch (SP), medium bare patch (MP) and large bare patch (LP); (2) the proposed method based on UAV images was able to estimate SSM (0-40 cm) with a satisfactory accuracy (R-2 = 0.89, P < 0.001); (3) all landscape indices of OV, with the exception of patch density, were positively correlated with SSM at plot scale, while most of the landscape indices of LP and IV showed negative correlations (P < 0.05). Our results indicated that patchiness intensified the spatial heterogeneity of SSM and potentially accelerated the alpine meadow degradation. Preventing the development of OV into IV and the expansion of LP is a critical task for alpine meadow management and restoration.

Land-cover changes and new ecosystem trajectories in Interior Alaska have altered the structure and function of landscapes, with regional warming trends altering carbon and water cycling. Notably, these changes include the increased distribution of tall woody vegetation, trees and shrubs, in landscapes that historically only supported low shrub vegetation cover. In Denali National Park, Alaska, this phenomenon has altered primary succession pathways towards tundra ecosystems with the establishment and expansion of balsam poplar (Populus balsamifera) trees. In this study, we examine how snow, soil, and vegetation processes interact within this altered successional pathway towards further landscape change following glacial recession. In a sequence of outflow terraces, we found that variations in snow depth, functional soil depth, leaf area index, overstory height, and understory height were all significantly correlated with each other, with those effects largely explained by the presence of poplar. Poplar-dominated plots had deeper snowpacks, deeper functional soil depths, taller overstory and shrub heights, and greater LAI than in non-poplar plots of the same landscape age. These findings suggest a feedback cycle where the establishment of taller vegetation (here, poplar) alters ecosystem processes in the following notable ways: taller vegetation is able to trap more snow by reducing wind exposure and limiting sublimation; this snow provides water through additional snowmelt and insulation, keeping soils warmer and lessening permafrost development, leading to deeper functional soil depths. This feedback demonstrates poplar's ability to modify the environment as an ecosystem engineer, engineering a trajectory away from the otherwise expected permafrost-underlain tundra.

Composite materials with different contents of silicon-modified pineapple leaf fiber (PALF), calcined oyster shell powder (OSP), and poly(butylene succinate) (PBS) were successfully prepared. Moreover, the flexural performance of the composite materials containing calcined oxazoline (OSP) was obviously enhanced. The addition of silicon-modified PALF contributed to the improvement of the material's thermal stability and affected its water absorption performance. Significant degradation differences were observed in PALF composite materials modified with glycidoxypropyl trimethoxysilane (Glymo) and PBS when adding calcined OSP. Formulations containing calcined OSP and epoxy-type silicon-modified PALF showed better adhesion to the PBS substrate, thereby exhibiting good flexural performance. The flexural strength of the formulation increased by 47% compared to pure PBS. This research accentuates the differences between epoxy-type silicon-modified PALF and PBS when integrated with calcined OSP. Biodegradation experiments demonstrated a notable 38.32% degradation after 105 days of the soil burial period. Furthermore, the study investigated the potential for manufacturing products, including tableware, storage boxes, and bowls, using injection molding techniques.

In this study, novel block copolymers consisting of poly(ethylene succinate) (PES) and poly(amino acid)s were synthesized, and their thermal and mechanical properties and biodegradability characteristics were investigated. Various types of poly(amino acid) units were successfully introduced using N-phenyloxycarbonyl amino acids (NPCs). The reactions between the terminally aminated PES and the NPCs were conducted by heating in N,N-dimethylacetamide at 65 degrees C. Structural analyses of the obtained polymers confirmed that the reaction with the NPCs proceeded from both ends of the terminally aminated PES. The results of material property measurements demonstrated that the melting point of the block copolymer containing poly(alanine) units increased beyond 200 degrees C while that of the original PES was similar to 100 degrees C. Additionally, its strain at break increased similar to 80-fold compared to that of PES with a similar molecular weight. The results of biodegradability tests using a soil suspension as an inoculum indicated that some of the block copolymers underwent biodegradation, and a correlation was observed between the biodegradability and the type and feed amount of NPC. Therefore, it was proposed that the degree, rate, and onset time of biodegradation could be controlled by altering the type and amount of incorporated poly(amino acid) units. This research may contribute to the optimal and facile synthesis of polyester-b-poly(amino acid) copolymers and to the expansion of the range of available biodegradable materials.

(1) Background: Plastic contamination is on the rise, despite ongoing research focused on alternatives such as bioplastics. However, most bioplastics require specific conditions to biodegrade. A promising alternative involves using microorganisms isolated from landfill soils that have demonstrated the ability to degrade plastic materials. (2) Methods: Soil samples were collected, and bacteria were isolated, characterized, and molecularly identified. Their degradative capacity was evaluated using the zone of clearing method, while their qualitative and structural degradative activity was assessed in a liquid medium on poly(butylene succinate) (PBS) films prepared by the cast method. (3) Results: Three strains-Bacillus cereus CHU4R, Acinetobacter baumannii YUCAN, and Pseudomonas otitidis YUC44-were selected. These strains exhibited the ability to cause severe damage to the microscopic surface of the films, attack the ester bonds within the PBS structure, and degrade lower-weight PBS molecules during the process. (4) Conclusions: this study represents the first report of strains isolated in Yucat & aacute;n with plastic degradation activity. The microorganisms demonstrated the capacity to degrade PBS films by causing surface and structural damage at the molecular level. These findings suggest that the strains could be applied as an alternative in plastic biodegradation.

BackgroundForensic entomotoxicology is a crucial field that studies the effects of drugs and poisons on carrion-feeding insects, particularly in crime investigations. Hydrogen cyanamide, a plant growth regulator, is hazardous and used in agriculture but is limited in some countries due to its high cost and severe toxicity. The terrestrial isopod Porcellio laevis plays a vital role in soil ecosystems and biosystem management. Accordingly, authors aimed to examine the impact of hydrogen cyanamide toxicity on arthropods, specifically Porcellio laevis, Musca domestica (House flies), and Sarcophaga sp. (Flesh flies) visiting decomposing covered/uncovered rat carrions, which could be relevant in forensic investigations. A total of 20 rats were divided into two control (I and II, covered/uncovered) and two treated groups (III and IV, covered/uncovered, euthanized using hydrogen cyanamide). Arthropods were gathered bi-daily during the initial week and then once daily for a duration of 1 month and were assessed for growth rate. Morphological and histological alterations were analyzed using light and electron microscopes.ResultsThe results revealed that hydrogen cyanamide caused a delay in postmortem interval (PMI) by 22-33 h in certain insect species, particularly in uncovered carrion. Severe damage was observed in the carrions of Groups III and IV, specifically Porcellio laevis.ConclusionA scanning electron microscope (SEM) would be beneficial for scrutinizing insects as postmortem toxicological specimens.

For maintenance and water saving reasons artificial or semi-artificial (hybrid) turfs have worldwide replaced natural turfs in many football-, soccer- and hockey stadiums. For obvious sustainability reasons the polymers which replace or reinforce the natural grass should be degradable, but still maintain specific mechanical properties over a certain period of time. This study intends to design and validate a poly(butylene succinate) (PBS) which fulfils these requirements. We investigated the dependency of PBS hydrolysis on molecular mass and temperature in order to develop a kinetic model for abiotic hydrolysis, which is the limiting step in PBS biodegradation. The hydrolysis rates were found to be temperature dependent according to the Arrhenius relationship k = A * exp(- EA R*T). A molecular mass dependency of the pre-exponential factor A was established and could befitted well by a linear equation without intercept for higher molecular weights. A polynomial approach led to a better fit for the whole molecular weight range. Both models have been validated on a degradation experiment in soil and were able to predict the molecular mass degradation within the typical standard deviations by size exclusion chromatography. Furthermore, we used the models to simulate the degradation of PBS samples in soil on available long-term soil temperature data. Previously published data on the relationship between molecular weight and mechanical properties were used to forecast the loss of functionality. This prediction was then compared to traction tests of aged PBS filaments used as fibre reinforcement of football hybrid turfs. The measurements match the predictions and show that a hybrid turf system with PBS fibres can be played on for at least 5.2 years before the fibres lose their mechanical properties.

Alkaline salts have more severe adverse effects on plant growth and development than neutral salts do. However, the adaptive mechanisms of plants to alkaline salt stress remain poorly understood, especially at the molecular level. The Songnen Plain in northeast China is composed of typical 'soda' saline-alkali soil, with NaHCO3 and Na2CO3 as the predominant alkaline salts (pH >= 9.2). Leymus chinensis can grow on this saline-alkali land, showing strong adaptability. We investigated the role of succinic acid and genes regulating its synthesis in the response to alkaline salt stress in L. chinensis roots. Compared to the neutral salt (NaCl) and high pH treatments, the alkaline salt (NaHCO3 and Na2CO3) treatment specifically caused changes in 11 organic acids, of which the increase in succinic acid was the greatest. The exogenous addition of succinic acid alleviates the damage of alkaline salt to L. chinensis roots. Further, two genes encoding succinyl-coenzyme A ligase (SUCLA) subunits that regulate succinic acid synthesis, LcSUCLA alpha and LcSUCLA(3, were identified; these genes interact and were localized within mitochondria. Overexpression of LcSUCLA alpha and LcSUCLA beta caused an increase in succinic acid and enhanced tolerance of NaHCO3 in transgenic rice seedlings. These results suggest that LcSUCLA alpha and LcSUCLA(3 may be involved in the response to alkaline salt stress through the regulation of succinic acid synthesis.

Plants can sustain various degrees of damage or compensate for tissue loss by regrowth without significant fitness costs. This tolerance to insect herbivory depends on the plant's developmental stage during which the damage is inflicted and on how much tissue is removed. Plant fitness correlates, that is, biomass and germination of seeds, were determined at different ontogenetic stages, vegetative, budding, or flowering stages of three annual brassicaceous species exposed to feeding by Pieris brassicae caterpillars at different intensities. Fitness costs decreased with progressive ontogenetic stage at which damage was inflicted. Feeding on meristem tissues on vegetative and budding plants limited the plant's ability to fully compensate for tissue loss, whereas feeding on flowers resulted in full compensation or overcompensation in Sinapis arvensis and Brassica nigra. Herbivory promoted germination of seeds in the following year, thereby causing a shift in relative contribution to the next year's generation at the expense of contributing to the long-lived seed bank. Herbivory intensity affected fitness correlates of B. nigra and to a lesser extent of Sisymbrium officinale, but not of S. arvensis, demonstrating that even closely related plant species can differ in their specific responses to herbivory and that these can differently affect reproductive output. In terms of fitness costs, annual plant species can be quite resilient to herbivory. However, the extent to which they tolerate tissue loss depends on the ontogenetic stage that is under attack. Seed persistence in the soil has been proposed as a bet-hedging strategy of short-lived species to increase long-term fitness. Herbivore-induced changes in seed germination can result in a shift in the relative contribution of seeds to the seed bank and next year's generation.