Microplastics (MPs) are an emerging global change factor with the potential to affect key agroecosystem services. Yet, MPs enter soils with highly variable properties (e.g., type, shape, size, concentration, and aging duration), reflecting their heterogeneous chemical compositions and diverse sources. The impacts of MPs with such varying properties on agroecosystem services remain poorly understood, limiting effective risk assessment and mitigation efforts. We synthesized 6315 global observations to assess the broad impacts of microplastic properties on key agroecosystem services, including crop productivity and physiology, soil carbon sequestration, nutrient retention, water regulation, and soil physical and microbial properties. MPs generally caused significant declines in aboveground productivity, crop physiology, water-holding capacity, and nutrient retention. However, the direction and magnitude of these effects varied considerably depending on the specific properties of MPs. The hazards posed by MPs to aboveground productivity, antioxidant systems, and root activity were size- and dose-dependent, with larger particles at higher concentrations inducing greater damage. Prolonged microplastic exposure impaired crop photosynthesis and soil nutrient retention, but most other ecosystem services (e.g., belowground productivity, antioxidant systems, and root activity) showed gradual recovery over time. Fiber-shaped MPs positively influenced crop aboveground and belowground productivity and soil carbon sequestration, potentially due to their linear configuration enhancing soil aggregation and connectivity. Polymer type emerged as the most prominent driver of the complex and unpredictable responses of agroecosystem services to MPs, with biodegradable polymers unexpectedly exerting larger negative effects on crop productivity, root activity, photosynthesis, and soil nutrient retention than other polymers. This synthesis underscores the critical role of microplastic properties in determining their ecological impacts, providing essential insights for property-specific risk assessment and mitigation strategies to address microplastic pollution in agroecosystems.
Saltwater intrusion (SWI) exposed the significant risk to rice production in the tropical lowland delta, especially under the contact of climate change. This study have developed the economic loss functions for both direct and indirect losses caused by SWI after investigating several regression models (such as: Ordinary Least Squares (OLS), Fixed Effects Model (FEM), Random Effects Model (REM), and Feasible Generalized Least Squares (FGLS), based on the 85 questionaires colleted in the tropical rice fields located in Ho Chi Minh City (HCMC). Direct damages were estimated based on cultivated area, rice yield, and salinity levels; while indirect damages were included the costs of water pumping, soil improvement, and irrigation infrastructure construction. The results showed that rice yield decreases sharply when salinity exceeds the threshold level of 1.5 parts per thousand, and indirect costs account for 9% of total damages. The new finding of this study is integrating indirect factors (water pumping, soil improvement, and irrigation infrastructure construction) into the economic loss function, enabling the estimation of both direct and indirect damages cause by SWI; which is a critical tool for water related disasters prevention and management, or land use planning, or developing socio-economic strategies to ensure food security for the deltas strongly affected by SWI.
Ongoing and widespread permafrost degradation potentially affects terrestrial ecosystems, whereas the changes in its effects on vegetation under climate change remain unclear. Here, we estimated the relative contribution of progressive active layer thickness (ALT) increases to vegetation gross primary productivity (GPP) in the northern permafrost region during the 21st century. Our results revealed that ALT changes accounted for 40% of the GPP increase in the permafrost region during 2000-2021, with amplified effects observed in late growing season (September-October) (43.2%-45.4%) and was especially notable in tundra ecosystems (51%-52.6%). However, projections indicated that this contribution could decrease considerably in the coming decades. Model simulations suggest that once ALT increments (relative to the 2001-2021 baseline) reach approximately 90 cm between 2035 and 2045, the promoting effect of ALT increase on vegetation growth may disappear. These findings provide crucial insights for accurately modelling and predicting ecosystem carbon dynamics in northern high latitudinal regions.
Silverleaf whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is a destructive insect pest damaging to diverse crops by vectoring several plant pathogenic viruses, which consequently causes economic losses in crop production. As the resistance of whiteflies to chemical insecticides is increasing, this study aimed to investigate the potential of entomopathogenic fungi as an alternative. A total of 72 entomopathogenic fungal isolates, collected from soils using Tenebrio molitor larvae as an insect baiting method, were assessed for their virulence against 2nd nymphs of whitefly. Their virulence was assayed by dipping whitefly-infested tomato leaves in fungal conidia suspensions at 1.0 x 107 conidia/mL. Among the tested isolates, two isolates of Beauveria bassiana JEF-462 and JEF-507 showed high virulence. In the assessment of virulence depending on conidia concentrations, the estimated LC50 values for JEF-462 and JEF-507 were similarly 8.7-14.0 x 107 conidia/mL. However, B. bassiana JEF-507 showed higher conidial productivity and thermotolerance on most of tested 12 grain substrates than B. bassiana JEF-462, and millet was the most suitable grain substrate. Additionally, siloxane as a surfactant was able to sufficiently exhibit the insecticidal activity of JEF-507 against whitefly nymphs compared with other surfactants. In a pot-based greenhouse trial, JEF-507 showed higher control efficacy than chemical insecticides, dinotefuran and spinetoram. This work suggests that B. bassiana JEF-507 could be competitively used as a biopesticide to control silverleaf whiteflies while overcoming current resistance issues. The JEF-507 isolate has been registered in Korea, 2022 and successfully commercialised as the name of Chongchae-Stop in this local market to control whitefly and thrips.
Environmental changes, such as climate warming and higher herbivory pressure, are altering the carbon balance of Arctic ecosystems; yet, how these drivers modify the carbon balance among different habitats remains uncertain. This hampers our ability to predict changes in the carbon sink strength of tundra ecosystems. We investigated how spring goose grubbing and summer warming-two key environmental-change drivers in the Arctic-alter CO2 fluxes in three tundra habitats varying in soil moisture and plant-community composition. In a full-factorial experiment in high-Arctic Svalbard, we simulated grubbing and warming over two years and determined summer net ecosystem exchange (NEE) alongside its components: gross ecosystem productivity (GEP) and ecosystem respiration (ER). After two years, we found net CO2 uptake to be suppressed by both drivers depending on habitat. CO2 uptake was reduced by warming in mesic habitats, by warming and grubbing in moist habitats, and by grubbing in wet habitats. In mesic habitats, warming stimulated ER (+75%) more than GEP (+30%), leading to a 7.5-fold increase in their CO2 source strength. In moist habitats, grubbing decreased GEP and ER by similar to 55%, while warming increased them by similar to 35%, with no changes in summer-long NEE. Nevertheless, grubbing offset peak summer CO2 uptake and warming led to a twofold increase in late summer CO2 source strength. In wet habitats, grubbing reduced GEP (-40%) more than ER (-30%), weakening their CO2 sink strength by 70%. One-year CO2-flux responses were similar to two-year responses, and the effect of simulated grubbing was consistent with that of natural grubbing. CO2-flux rates were positively related to aboveground net primary productivity and temperature. Net ecosystem CO2 uptake started occurring above similar to 70% soil moisture content, primarily due to a decline in ER. Herein, we reveal that key environmental-change drivers-goose grubbing by decreasing GEP more than ER and warming by enhancing ER more than GEP-consistently suppress net tundra CO2 uptake, although their relative strength differs among habitats. By identifying how and where grubbing and higher temperatures alter CO2 fluxes across the heterogeneous Arctic landscape, our results have implications for predicting the tundra carbon balance under increasing numbers of geese in a warmer Arctic.
The productivity of tomato fruit on the western shore of Lake Abaya in Ethiopia was severely hindered by saline-sodic damage. This study aimed to assess the impact of applying gypsum and adopting soil mulching agricultural technology to improve the issues of salt-affected soil in the region. The treatments consisted of a control group (T1), mulching (T2), gypsum application (T3), and a combination of gypsum (half level) and mulching (T4). Application rates of gypsum and straw mulching were 14.5 and 15 tons/ha, respectively. The mean total seasonal crop water consumptions of tomatoes were 378 mm (non-mulching) and 333.02 mm (mulching). Straw mulching saved an average of 13.2% of soil water compared with non-mulching treatments. At the end of the growing season, exchangeable sodium percentage was decreased by 42.3% (T2), 38.1% (T3), and 43.8% (T4) compared with control T1. The pH levels at the experimental site experienced reductions of 15.1% (T2), 1.1% (T3), and 14% (T4) compared with T1. The soil electric conductivity of the soil at the end of the tomato growing period was decreased by 59.6% (T2), 19.2% (T3), and 46.2% (T4). The average land productivity of tomatoes in the current study was 14.9(c )tons/ha (T1), 16.2(b) tons/ha (T2), 15.0(c )tons/ha (T3), and 18.6a tons/ha (T4). The average water productivity of tomatoes in the current study was 5.5c kg/m(3) (T1), 7.2(b )kg/m(3) (T2), 6.5 (c) kg/m(3) (T3), and 7.8a kg/m(3) (T4). The benefit-cost ratios for T1, T2, T3, and T4 were 1.67, 2.2, 1.78, and 2.4, respectively. The optimal strategy for mitigating saline-sodic soil and ensuring sustainable tomato production involves applying gypsum at half the recommended level along with implementing straw mulching.
The European spruce bark beetle (Ips typographus) is an insect species that causes significant damage to Norway spruce (Picea abies) forests across Europe. Infestation by bark beetles can profoundly impact forest ecosystems, affecting their structure and composition and affecting the carbon cycle and biodiversity, including a decrease in net primary productivity (NPP), a key indicator of forest health. The primary objective of this study is to enhance our understanding of the interplay among NPP, bark beetle infestation, land surface temperature (LST), and soil moisture content as key components influencing the effects of climate change-related events (e.g., drought) during and after a drought event in the Bavarian Forest National Park in southeastern Germany. Earth observation data, specifically Landsat-8 TIR and Sentinel-2, were used to retrieve LST and leaf area index (LAI), respectively. Furthermore, for the first time, we incorporated a time series of high-resolution (20 m) LAI as a remote sensing biodiversity product into a process-based ecological model (LPJ-GUESS) to accurately generate high-resolution (20 m) NPP products. The study found a gradual decline in NPP values over time due to drought, increased LST, low precipitation, and a high rate of bark beetle infestation. We observed significantly lower LST in healthy Norway spruce stands compared to those infested by bark beetles. Likewise, low soil moisture content was associated with minimal NPP value. Our results suggest synergistic effects between bark beetle infestations and elevated LST, leading to amplified reductions in NPP value. This study highlights the critical role of integrating high-resolution remote sensing data with
Extreme climate events are increasingly damaging forests, particularly in Europe's Alps. These disturbances lead to more damaged timber, necessitating rapid salvage operations to preserve timber value and protect ecosystems. However, salvage logging, though essential, raises concerns about its environmental impact, especially on soil conservation and forest regeneration. To mitigate these effects, best practices such as leaving logging residues and avoiding wet soils are recommended. Nevertheless, fuel efficiency remains a critical concern. This study focuses on addressing gaps in understanding forwarder productivity in salvage logging, considering factors such as assortment number, extraction distance, and payload. Utilizing Automatic Work-Element Detection (AWED) for data collection, this study enhances fuel efficiency analysis. Findings show that the average cycle time was 27.4 min, with 4.9 L of fuel consumed per cycle. Each cycle covered 241.3 m, extracting 11.7 m(3) of timber, yielding a productivity rate of 31.6 m(3) per machine hour and a fuel efficiency of 0.4 L per m(3) and per 100 m. Traveling was the most time- and fuel-intensive task. Assortment type significantly impacted loading time and fuel consumption, with short sawlogs requiring fewer crane cycles. Key factors influencing productivity and fuel efficiency were average log volume, distance, payload, and slope.
Southwest China, characterized by its climate sensitivity and ecological fragility, is experiencing heightened vulnerability to recurrent extreme drought due to climate change. However, not all drought events impart identical damage effects on terrestrial ecosystems. The ecosystem's response to drought becomes intricately diverse and is remain poorly understood in this region. Here, we comprehensively distinguish the inhibiting and promoting effects of cumulative drought on vegetation productivity and the modulation of hydrothermal conditions using various remote-sensing data and meteorological observations. Our results show that cumulative drought exerts pronounced inhibiting and promoting effects on vegetation productivity in 57.3% and 25.0% of vegetated area in southwest China, respectively, and shows large discrepancies in different geomorphic settings and different vegetation types. Particularly, vegetation productivity is more easily inhibited by cumulative drought in the karst landform with inadequate water-holding capacity. The croplands suffer the most inhibited effects and hardly benefit from the cumulative drought because that most of croplands are mainly distributed on the karst landform. Productivity for much of the grasslands is most strongly promoted by cumulative drought with relatively low temperature over western Sichuan and northwestern Yunnan, where with rich solar radiation can compensate energy for vegetation growth and less precipitation prevents prolonged waterlogging of plant roots owing to soil water saturation. Forests have well-developed deep root systems and can draw deep groundwater to compensate for water shortages during prolonged droughts, making them the least inhibited by cumulative drought. Savannas are the second weakly inhibited by cumulative drought, ranking below forests owing to their intermediate ecological character, straddling the boundaries between grasslands and forests. Overall, this study significantly advances our knowledge of the effects of cumulative drought on vegetation productivity and the role of hydrothermal conditions, providing valuable insights for efforts to mitigate cumulative drought risk under changing climate conditions.
In conventional agricultural practices, pesticides are applied to protect crops from harmful insect pests; however, pervasive usage in high-yield crop systems poses a significant risk to the viability and sustainability of agroecosystems. Agricultural output may be adversely affected by pesticide deposition in the soil as it affects biochemical interactions between plants and soil. Pesticides cause oxidative stress by blocking physiological and biochemical pathways and disrupting the photosynthetic machinery of plants. When exposed to abiotic challenges, plant growth regulators (PGRs) such as auxin, gibberellins, cytokinin and abscisic acid (ABA), salicylic acid (SA), jasmonic acid (JA), brassinosteroids (BR), and 24-epibrassinolides (EBL) reduce pesticide toxicity by strengthening antioxidant defence mechanisms and enhancing tolerance to stressful conditions. By modulating a variety of physio-biochemical mechanisms, PGRs reduce pesticide toxicity in intact plants. Furthermore, PGRs eliminate reactive oxygen species (ROS) generation by inducing antioxidant enzyme production. Pesticide residues in plant compartments are reduced as a result of PGR-mediated increase in pesticide degradation. This review provides a detailed account of the potential role of PGRs in pesticide detoxification and growth promotion in plants. This work examines several elements of plant pesticidal reactions and assesses how PGRs support plants in tolerating pesticides. The underlying mechanisms during pesticide stress are also discussed. The need for additional study on PGR applications is also emphasized.