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Accurate estimation of above-ground biomass (AGB) is a crucial aspect of ecosystem management, particularly in game reserves like the Cradle Nature Reserve. This study utilises 2018 AGB at a 50 m resolution to estimate AGB by integrating RGB drone imagery vegetation indices, normalised digital surface model (nDSM), and field-measured chlorophyll concentrations. Principal Component Analysis (PCA) and stepwise regression were employed to identify significant predictors of AGB. The final model for non-riparian forest area explained 66% (R2 = 0.66), with nDSM and red-blue vegetation index (RBVI) as key predictors. In contrast, the riparian model explained 42% (R2 = 0.42), with chlorophyll content and blue-green vegetation index (BGVI) as significant predictors. Our findings highlight the significant influence of nDSM and chlorophyll content on AGB. Vegetation indices such as the green-blue vegetation index (GBVI), green-red vegetation index (GRBI), and RBVI showed diverse correlations with chlorophyll levels, capturing plant greenness and vitality and directly influencing biomass. Comparative analyses of riparian and non-riparian vegetation models revealed that chlorophyll content and BGVI were significant predictors in riparian zones, reflecting interactions between water availability, nutrient flow, and vegetation health. In non-riparian areas dominated by tall trees, nDSM and RBVI were key predictors, underscoring the importance of plant height and stress indicators. This study underscores the effectiveness of drones in remote sensing applications for forest management. These findings contribute to the growing body of knowledge on drone-based biomass estimation, offering valuable insights for managing and conserving ecosystems such as the Cradle Nature Reserve, thereby providing practical implications for ecosystem management and conservation. [ABSTRACT FROM AUTHOR]

Since 2007, large-scale blooms have periodically broken out in the Yellow Sea, leading to serious economic and ecological problems in the surrounding coastal environments. Previous studies reported that the blooms originated in the Rudong oceanic area of the southern Yellow Sea and drifted almost 400 km into the Qingdao oceanic area of the northern Yellow Sea. In this study, chlorophyll concentrations, chlorophyll fluorescence, growth rates, and reproductive characteristics of floating Ulva prolifera collected along the Yellow Sea coast were assessed. The results revealed that these four physiological parameters in the Rudong area at the bloom source were considerably higher (2.02 mg/g, 0.68, 28.49% d−1, and 4 × 107, respectively) than in the Qingdao area (0.34 mg/g, 0.31, 5.23% d−1, and 0.67 × 107, respectively). However, the abundance of microscopic propagules of Ulva in the Qingdao area (3980 ind/l) was significantly higher than that in the Rudong area (667 ind/l). These findings help increase our understanding of the formation of the world's largest Ulva macroalgal blooms. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) and salicylic acid (SA) are two important signaling molecules, which could alleviate chlorosis of peanut under iron (Fe) deficiency. Here, we further investigated the mechanism of different combinations of sodium nitroprusside (SNP, a nitric oxide donor) and SA supplying in alleviation Fe deficiency symptoms and selected which is the best combination. Thus, peanut was cultivated in hydroponic culture under iron limiting condition with different combinations of SNP and SA application. After 21 days, Fe deficiency significantly inhibited peanut growth, decreased soluble Fe concentration and chlorophyll contents, and disturbed ionic homeostasis. In addition, the content of reactive oxygen species (ROS) and malondialdehyde (MDA) concentration increased, which led the lipid peroxidation. Application of SNP and SA significantly changed Fe trafficking in cells and organs, which increased Fe uptake from nutrient solution, and transport from root to shoot, enhanced the activity of ferric-chelate reductase (FCR), that increased the available Fe in cell organelles, and the active Fe, chlorophyll contents in leaves. Furthermore, ameliorated the inhibition of calcium (Ca), magnesium (Mg) and zinc (Zn) uptake and promoted plant growth in Fe deficiency. At the same time, it increased the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) to protect the plasmolemma from peroxidation. Results demonstrated that different combinations of SNP and SA application could alleviate the chlorosis of peanut in Fe deficiency by various mechanisms. Such as increased the available Fe and chlorophyll concentrations in leaves, improved the activities of antioxidant enzymes and modulated the mineral elements balance and so on. Foliar application of SNP and SA is the best to protect leaves while directly adding them into nutrient solution is the best to protect roots. These results also indicated that the effects of SNP and SA supplying together to leaves or roots are better than respectively adding to roots and spraying to leaves. The best combination is foliar application of SNP and SA. [ABSTRACT FROM PUBLISHER]