Search Results (337)

Carbon dioxide (CO₂) emissions due to human activities are responsible for approximately 80% of the drivers of global warming, resulting in a 1.1 °C increase above pre-industrial temperatures. This study quantified the CO₂ assimilation and productivity of the brown macroalgae Lessonia spicata in the central Pacific coast of Chile, across seasonal and daily cycles, under different environmental stressors, such as temperature and solar irradiance. Measurements were performed using an infra-red gas analysis (IRGA) instrument which had a chamber allowing for precise quantification of CO₂ concentrations; additional photophysiological and biochemical responses were also measured. CO₂ assimilation, along with the productivity and biosynthesis of proteins and lipids, increased during the spring, coinciding with moderate temperatures (~14 °C) and high photosynthetically active radiation (PAR). Furthermore, the increased production of photoprotective and antioxidant compounds, including phenolic compounds, and carotenoids, along with the enhancement of non-photochemical quenching (NPQ), contribute to the effective photoacclimation strategies of L. spicata. Principal component analysis (PCA) revealed seasonal associations between productivity, reactive oxygen species (ROSs), and biochemical indicators, particularly during the spring and summer. These associations, further supported by Pearson correlation analyses, suggest a high but seasonally constrained photoacclimation capacity. In contrast, the reduced productivity and photoprotection observed in the summer suggest increased physiological vulnerability to heat and light stress. Overall, our findings position L. spicata as a promising nature-based solution for climate change mitigation. Full article

Agrivoltaic (Agri-PV) systems face the critical challenge of balancing photovoltaic energy generation with crop productivity, yet systematic approaches to quantifying the trade-offs between these objectives remain scarce. In this study, we identify nine essential design indicators: panel tilt angle, elevation, photovoltaic coverage ratio, shading factor, land equivalent ratio, photosynthetically active radiation (PAR) utilization, crop yield stability index, water use efficiency, and return on investment. We introduce a novel dual matrix Analytic Hierarchy Process (AHP) to evaluate their relative significance. An international panel of eighteen Agri-PV experts, encompassing academia, industry, and policy, provided pairwise comparisons of these indicators under two objectives: maximizing annual energy yield and sustaining crop output. The high consistency observed in expert responses allowed for the derivation of normalized weight vectors, which form the basis of two Weighted Influence Matrices. Analysis of Total Weighted Influence scores from these matrices reveal distinct priority sets: panel tilt, coverage ratio, and elevation are most influential for energy optimization, while PAR utilization, yield stability, and elevation are prioritized for crop productivity. This methodology translates qualitative expert knowledge into quantitative, actionable guidance, clearly delineating both synergies, such as the mutual benefit of increased elevation for energy and crop outcomes, and trade-offs, exemplified by the negative impact of high photovoltaic coverage on crop yield despite gains in energy output. By offering a transparent, expert-driven decision-support tool, this framework enables practitioners to customize Agri-PV system configurations according to local climatic, agronomic, and economic contexts. Ultimately, this approach advances the optimization of the food energy nexus and supports integrated sustainability outcomes in Agri-PV deployment. Full article

Typhoons are major climate disturbances that significantly impact coastal ecosystems, particularly mangrove forests. This study examines the effects of typhoons on mangrove communities at different stages of recovery, focusing on how environmental factors influence carbon storage and net ecosystem exchange (NEE). Three mangrove sites were selected based on their recovery age: young, moderately restored, and mature. The results revealed that typhoons had the most pronounced effect on young mangroves, resulting in significant reductions in both above-ground and soil carbon storage. In contrast, mid-aged and mature mangroves demonstrated greater resilience, with mature mangroves recovering most rapidly in terms of community structure and carbon storage. Key factors such as wind speed, heavy rainfall, and changes in photosynthetically active radiation (PAR) contributed to carbon storage losses, particularly in young mangrove forests. This study underscores the importance of recovery age in determining mangrove resilience to extreme weather events and offers insights for enhancing restoration and conservation strategies to mitigate the impacts of climate change on coastal carbon sequestration. Full article

Increased market demand for plant herbs has prompted growers to ensure a continuous and assured supply of superior nutritional quality over the years. Apart from the nutritional value, culinary herbs contain phytochemical benefits that can improve human health. However, a significant amount of research has focused on enhancing yield, frequently overlooking the impact of production practices on the antioxidant and phytonutritional content of the produce. Thus, the study aimed to evaluate the yield, phytonutrients, and essential mineral profiling in selected aromatic herbs and their intricate role in nutritional quality when grown under different production systems. Five selected aromatic herbs (coriander, rocket, fennel, basil, and moss-curled parsley) were evaluated at harvest when grown under three production systems: in a gravel-film technique (GFT) hydroponic system and in soil, both under the 40% white shade-net structure, as well as in a soilless medium using sawdust under a non-temperature-controlled plastic tunnel (NTC). The phytonutritional quality properties (total phenolic, flavonoids, β-carotene-linoleic acid, and condensed tannins contents) as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH) were assessed using spectrophotometry, while vitamin C and β-carotene were analyzed using HPLC-PDA, and leaf mineral content was evaluated using ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometry). The results show that the health benefits vary greatly owing to the particular culinary herb. The fresh leaf mass (yield) of coriander, parsley, and rocket was not significantly affected by the production system, whereas basil was high in soil cultivation, followed by GFT. Fennel had a high yield in the GFT system compared to in-soil and in-soilless cultivation. The highest levels of vitamin C were found in basil leaves grown in GFT and in soil compared to the soilless medium. The amount of total phenolic and flavonoid compounds, β-carotene, β-carotene-linoleic acid, and DPPH, were considerably high in soil cultivation, except on condensed tannins compared to the GFT and soilless medium, which could be a result of Photosynthetic Active Radiation (PAR) values (683 μmol/m²/s) and not favoring the accumulation of tannins. Overall, the mineral content was greatly influenced by the production system. Leaf calcium and magnesium contents were highly accumulated in rockets grown in the soilless medium and the GFT hydroponic system. The results have highlighted that growing environmental conditions significantly impact the accumulation of health-promoting phytonutrients in aromatic herbs. Some have positive ramifications, while others have negative ramifications. As a result, growers should prioritize in-soil production systems over GFT (under the shade-net) and soilless cultivation (under NTC) to produce aromatic herbs to improve the functional benefits and customer health. Full article

Background: Understanding canopy light interception is essential for optimizing forage production and improving the efficiency of grazing systems. Accurate quantification of photosynthetically active radiation (PAR) intercepted by the canopy allows for better estimation of crop coefficients and growth dynamics. This study aimed to assess the forage mass and nutritional value of Guinea grass pastures managed under two grazing frequencies, defined by 90% and 95% light interception (LI) measured using AccuPar equipment, and two post-grazing stubble heights (30 and 50 cm). Evaluations were conducted during both the rainy season and a dry year to capture seasonal variability in pasture performance. Methods: The experimental design was of completely randomized blocks with four replications. Results: The treatment whit 90% LI resulted in higher values of crude protein and digestible. However, 95% LI resulted in higher values of neutral detergent insoluble nitrogen and acid detergent insoluble nitrogen values in grass pastures Guinea. The highest value of forage mass in Guinea grass was reported with 95% LI in association with a post-grazing height of 30 cm. Conclusions: Management of light interception at 90% provided a reduced amount of forage with better nutritional value. Pasture management considering the light interception technology with the AccuPar equipment was efficient as a pattern for interrupting pasture regrowth in the vegetative phase. Full article

As an essential part of terrestrial ecosystems, forests are key to sustaining ecological balance, supporting the carbon cycle, and offering various ecosystem services. In recent years, forests in Southwest China have experienced notable greening. However, the rising occurrence and severity of droughts present a significant threat to the stability of forest ecosystems in this region. This study adopted the near-infrared reflectance of vegetation (NIRv) and the lag-1 autocorrelation of NIRv as indicators to assess the dynamics and resilience of forests in Southwest China. We identified a progressive decline in forest resilience since 2008 despite a dominant greening trend in Southwest China’s forests during the last 20 years. By developing the eXtreme Gradient Boosting (XGBoost) model and Shapley additive explanation framework (SHAP), we classified forests in Southwest China into coniferous and broadleaf types to evaluate the driving factors influencing changes in forest resilience and mapped the spatial distribution of dominant drivers. The results showed that the resilience of coniferous forests was mainly driven by variations in elevation and land surface temperature (LST), with mean absolute SHAP values of 0.045 and 0.038, respectively. In contrast, the resilience of broadleaf forests was primarily influenced by changes in photosynthetically active radiation (PAR) and soil moisture (SM), with mean absolute SHAP values of 0.032 and 0.028, respectively. Regions where elevation and LST were identified as dominant drivers were mainly distributed in coniferous forest areas across central, eastern, and northern Yunnan Province as well as western Sichuan Province, accounting for 32.9% and 20.0% of the coniferous forest area, respectively. Meanwhile, areas where PAR and SM were dominant drivers were mainly located in broadleaf forest regions in Sichuan and eastern Guizhou, accounting for 29.9% and 27.7% of the broadleaf forest area, respectively. Our study revealed that the forest greening does not necessarily accompany an enhancement in resilience in Southwest China, identifying the driving factors behind the decline in forest resilience and highlighting the necessity of differentiated restoration strategies for forest ecosystems in this region. Full article

Agriphotovoltaic (Agri-PV) systems are a dual-purpose solution for resolving land utilization conflicts through combining agricultural practices and photovoltaic power generation. However, the reduced light intensities and altered microclimatic conditions under PV modules may have negative effects on the productivity of crops. This study investigated whether incorporating arbuscular mycorrhizal fungi (AMF) inoculation into Agri-PV systems could mitigate such limitations for mint cultivation (Mentha arvensis and Mentha × piperita). A field trial was conducted in Bandırma, Türkiye, where both mint species were grown under and between PV panels, with and without AMF. The photosynthetically active radiation (PAR), temperature, fresh biomass, nutrient uptake, and essential oil content were evaluated. PAR was reduced by more than 90% under panels, while air temperatures were 1.0–1.6 °C lower than those in the between-panel areas. AMF inoculation significantly improved the yield and quality. In Mentha arvensis, the fresh herb yield increased by 43.4% (from 10,620 to 15,230 kg ha⁻¹), and the essential oil content reached 10.08% under between-panel mycorrhizal conditions. For Mentha × piperita, the highest menthol concentration (30.38%) was observed exclusively in between-panel plots with AMF. In contrast, the highest oil content (4.50%) was achieved under shaded, mycorrhizal conditions, indicating that both light exposure and microbial interactions shape biochemical responses. This is the first study to demonstrate the synergistic impact of AMF inoculation and agrivoltaic shading on essential oil crops. This paper presents a novel and sustainable model that enhances crop productivity and biochemical quality in solar-integrated agriculture. Full article

Photosynthetically Active Radiation (PAR) is critical for sustaining plant growth in the ground and on building surfaces, but how to accurately predict PAR availability in a complex urban environment can be a challenge. Using an advanced ray-tracing software (Radiance 4.0) and local weather data, this study presents a dynamic analysis of the effects of layout, façade orientation and height on PAR availability in four high density residential areas in Shanghai city, China. A metric system was also adopted using three light level requirements of outdoor plants (low, medium, high light levels). Key findings included: (1) the urban layout with the highest ratio of building height to north–south facing adjacent building separation achieved the higher levels of PAR availability for low/medium light level plants and the lower levels of PAR availability for high-light plants for middle and low façades and the ground, while high façades in all layouts could see similar PAR availability for all plants. (2) The PAR availability for low/medium-light plants decreased with the increasing façade height, while the PAR availability for high-light plants showed the opposite trend. (3) The north façade and its ground had higher levels of PAR availability for low/medium-light plants and lower levels of PAR availability for high-light plants than other façades. (4) All layouts offered more opportunities to apply high-light and medium-light plants at façades and the ground. Full article

Photosynthetically active radiation (PAR) is crucial for plant growth, influencing photosynthesis efficiency and crop yield. The increasing adoption of controlled-environment agriculture (CEA) necessitates precise PAR monitoring. The high cost of commercial PAR sensors, however, limits their accessibility and widespread use, creating a growing need for a low-cost alternative capable of reliable deployment in diverse agricultural environments. Building on recent advancements in PAR sensing using multi-channel spectral sensors such as the AS7341 and AS7265, this study develops the electronics for an AS7341-based, open-source, cost-effective (~USD 50) PAR sensor validated across a broad PPFD range and conditions, ensuring reliability and ease of replication. It uses a relatively simple multi-linear regression that offers real-time applications without energy intensive machine learning. The developed sensor is calibrated against the industry-standard Apogee SQ-500SS PAR sensor in four distinct farming environments: (i) horizontal grow lights, (ii) vertical agrotunnel lighting, (iii) agrivoltaics, and (iv) in greenhouses. A mean error ranging from 1 to 5% indicates its suitability for controlled environment farming and continuous data logging. The open-source hardware design and systematic installation guidelines enable users to replicate, calibrate, and integrate the sensor with minimal background in electronics and optics. Full article

Photosynthetically Active Radiation (PAR) is a critical indicator of plant photosynthesis and ecosystem energy flux. Accurate measurement of PAR is essential in agriculture, ecological research, and environmental management. This paper reviews recent developments and applications of PAR measurement technologies, focusing on recent advances in commercial PAR sensors, low-cost sensors, and remote sensing techniques. First, we outline the definition of PAR and further discuss in situ measurements and indirect estimation approaches. The technical principles, sources of error, and practical applications of commercial PAR sensors are presented at the next section. On the contrary, we also introduce the potential of low-cost sensors, particularly emphasizing the role of citizen science initiatives and open-source technologies in promoting widespread PAR measurement. Furthermore, the technical principles underlying remote sensing-based PAR estimation on a global scale are summarized, along with the application prospects of machine learning and satellite-derived product analysis techniques. Finally, this paper comprehensively reviews the challenges confronting PAR measurement and explores potential sensor innovations that may arise from future technological advancements. Full article

Particulate organic carbon (POC) plays a crucial role in oceanic climate change. However, existing research is limited by several factors, including the scarcity of long-term data, extensive datasets, and a comprehensive understanding of POC dynamics. This study utilizes monthly average POC remote sensing data from the MODIS/AQUA satellite to analyze the spatiotemporal variations of POC in the East China Sea from 2003 to 2022. Employing correlation analysis, spatial autocorrelation models, and the Geodetector model, we explore responses to key influencing factors such as climatic elements. The results indicate that POC concentrations are higher in the western nearshore areas and lower in the eastern offshore regions of the East China Sea (ECS). Additionally, concentrations are observed to be lower in southern regions compared to northern ones. From 2003 to 2022, POC concentrations exhibited a fluctuating downward trend with an average annual concentration of 121.05 ± 4.57 mg/m³. Seasonally, monthly average POC concentrations ranged from 105.48 mg/m³ to 158.36 mg/m³; notably higher concentrations were recorded during spring while summer showed comparatively lower levels. Specifically, POC concentrations peaked in April before rapidly declining from May to June—reaching a minimum—and then gradually increasing again from June through December. Correlation analysis revealed significant influences on POC levels by particulate inorganic carbon (PIC), sea surface temperature (SST), chlorophyll (Chl), and photosynthetically active radiation (PAR). The Geodetector model further elucidated that these factors vary in their impact: Chl was identified as having the strongest influence (q = 0.84), followed by PIC (q = 0.75) and SST (q = 0.64) as primary influencing factors; PAR was recognized as a secondary factor with q = 0.30. This study provides new insights into marine carbon cycling dynamics within the context of climate change. Full article

Habitat suitability assessment for forest and grassland ecosystems is a critical component of ecological restoration and land use planning in the Loess Plateau, aiming to advance soil and water conservation and foster sustainable ecological environment development. Despite progress in vegetation restoration, systematic evaluations of habitat suitability in complex geomorphic regions like the Loess Plateau remain scarce, particularly in balancing hydrological and ecological trade-offs. The Yanhe River Basin (7725 km²), a sediment-prone tributary of the Yellow River, exemplifies the challenges of soil erosion and semi-arid climatic constraints, making it a critical case for evaluating restoration strategies. This study employed a comprehensive approach utilizing Analytic Hierarchy Process (AHP), Geographic Detector, mathematical statistics, and other methods. An evaluation indicator system and methodology were established to assess the suitability of forest and grassland habitats in the Yanhe River Basin, evaluating the suitability and quality improvement potential under the current land use conditions. The results indicate: (1) The dominant factors influencing the suitable distribution of forests include photosynthetically active radiation (PAR), soil total phosphorus content, annual precipitation, and elevation. For grasslands, the dominant factors include photosynthetically active radiation, annual average temperature, elevation, and annual precipitation. (2) In the watershed, forestland and grassland areas classified as moderately suitable or higher cover 1064.9 km² and 4196.9 km², accounting for 91.9% and 94.7% of their total respective areas, indicating a generally rational spatial allocation of forest and grassland ecosystems. (3) The improvable area for forests measures 366 km² (34.4% of moderately or higher suitability zones), with most already meeting coverage thresholds. In contrast, grasslands have an improvable area of 2491.6 km² (59.4% of moderately or higher suitability zones), where over half of the area remains below coverage thresholds corresponding to their habitat conditions. (4) Forests can adopt natural restoration-focused low-intensity interventions through strengthened closure management, while grasslands require spatially tailored measures—such as precipitation interception and enhanced stewardship—targeting suitability-based potential grades, collectively achieving overall improvement in grassland vegetation coverage. This study represents the first systematic evaluation of forest–grassland habitat suitability in the Yanhe River Basin, elucidating its spatial distribution patterns and providing critical insights for watershed-scale ecological restoration. Full article

Moringa oleifera (LAM) is a multipurpose tree species with extensive pharmacological and ethnomedicinal properties. Production of important medicinal plants is facing decline under changing climatic conditions, which brings along exacerbated abiotic stresses like salinity and intraspecific competition, particularly high planting densities. Increasing plant density is seen as a strategy to increase production; however, the intraspecific competition and a lack of arable land limit productivity. Salinity has been estimated to harm approximately six percent of the Earth’s landmass. This leads to a loss of over 20% of agricultural output annually. These stressors can significantly curtail moringa’s growth and yield potential. Literature designates that Arbuscular Mycorrhizal Fungi (AMF), ubiquitous soil microorganisms forming symbiotic associations with plant roots, offer a promising avenue for mitigating these stresses. This narrative review aims to investigate the utilization of AMF to alleviate the detrimental effects of salinity and high planting density on Moringa oleifera. The different adaptive strategies M. oleifera undergoes to mitigate both stressors are explored. The review found that AMF inoculation enhances plant tolerance to these stressors by improving nutrient acquisition, water relations, and activating stress response mechanisms. By facilitating improved nutrient and water absorption, AMF enhance root architecture, modulate ROS scavenging mechanisms, and promote optimal biomass allocation, ensuring better survival in high-density plantings. Furthermore, AMF-mediated stress alleviation is linked to enhanced physiological efficiency, including increased chlorophyll content, root–shoot biomass balance, and ion homeostasis. This review is important because it could provide insights into a sustainable, natural solution for improving the resilience of Moringa oleifera under adverse environmental conditions, with potential applications in global agriculture and food security. Future research should prioritize identifying and characterizing moringa-specific AMF species and evaluate the long-term efficacy, feasibility, and economic viability of AMF application in real-world moringa cultivation systems to fully harness the potential of AMF in moringa cultivation. Full article

Understanding the spatial–temporal distribution of photosynthetically active radiation (PAR) within crop canopies is crucial for optimizing planting structures to enhance resource use efficiency and improve crop yields. While high planting densities are commonly employed to increase yields, this practice can lead to issues such as early leaf senescence and reduced biomass. This study investigates the impact of varying planting densities on PAR dynamics, canopy structure, and yield formation in maize over two years. Key findings include the following: (1) higher planting density significantly increased grain yield, biological yield, and LAI, although HI decreased; (2) canopy light distribution varied with planting density, with the middle layers intercepting the most light, particularly during the grain filling stage; (3) a density of 83,000 plants·ha⁻¹ was the most efficient for maximizing yield and WUE, although high accumulated temperatures negatively impacted yields. These results suggest that adjusting planting density can enhance resource use efficiency in maize farming, particularly in regions with variable water availability and climate challenges. Future research should explore the long-term effects of planting density on soil health, water use efficiency, and crop resilience under varying environmental conditions. Additionally, studies integrating precision agriculture technologies to fine-tune planting density and water management in response to climate change are essential for ensuring sustainable maize production and food security in the future. Full article

To investigate the light and temperature environmental parameters of photovoltaic greenhouses in tropical areas, this study adopted experimental measurement and simulation methods to test and simulate the photosynthetically active radiation (PAR), relative temperature and humidity, and other environmental parameters inside and outside two types of serrated photovoltaic greenhouses in Langheng Village, Yangpu, Hainan. The study aimed to explore the distribution laws of PAR, light transmission rates, and relative humidity and temperature inside and outside double-slope and single-slope photovoltaic greenhouses. The ridges of both types of greenhouses run east to west, with photovoltaic panels arranged on the south-facing slopes, covering 57% of the area. The results show the following: (1) The trends of PAR inside and outside both types of photovoltaic greenhouses were consistent across all seasons, with the annual average values were 164.98 μmol/(m²·s) for double-slope and 127.59 μmol/(m²·s) for single-slope; (2) The annual average light transmission rates were 23.91% for double-slope and 19.17% for single-slope; (3) The average indoor temperatures in both types of greenhouses were higher than outside in all seasons, with a temperature difference ranging between 1 and 3 °C; (4) The indoor relative humidity in both types of greenhouses was higher than outside, with the difference reaching up to 6% during summer and autumn; (5) The annual light transmission rates for both types of greenhouses were simulated using Design Builder. The simulation results were generally consistent with the measured values, with the simulated values being higher overall than the measured ones by an average difference within 5%. In summary, the average light transmission rate of the double-slope photovoltaic greenhouse was 4.74% higher that of the single-slope photovoltaic greenhouse and the PAR was 37.39 μmol/(m²·s) higher than the single-slope. Additionally, the average temperature in the double-slope greenhouse was slightly higher and the relative humidity was slightly lower than that in the single-slope greenhouse. Both types of greenhouses could meet the light, temperature, and humidity requirements for cultivating leafy vegetables in tropical areas. Except for the temperature parameters in summer, the performance of the double-slope photovoltaic greenhouse was also better. The Design Builder simulation results showed little difference to the actual measurements and their trends were also consistent. The light transmission rate of photovoltaic greenhouses can be simulated by setting the overall light transmission coefficient of the light-transmitting roofing materials. Full article