Search Results (212)

In the irrigation districts of Northern China, the flood resources utilization for deep storage irrigation, which is essentially characterized by active excessive irrigation, aims to have the potential to mitigate freshwater shortages, and long-term groundwater overexploitation. It is crucial to detect the effects of irrigation amounts on agricultural yield and the mechanisms under deep storage irrigation. A three-year field experiment (2020–2023) was conducted in the Guanzhong Plain, according to five soil wetting layer depths (RF: 0 cm; W1: control, 120 cm; W2: 140 cm; W3: 160 cm; W4: 180 cm) with soil saturation water content as the irrigation upper limit. Results exhibited that, compared to W1, the W2, W3, and W4 treatments led to the increased plant height, leaf area index, and dry matter accumulation. Meanwhile, the W2, W3, and W4 treatments improved kernel weight increment achieving maximum grain-filling rate (W_max), maximum grain-filling rate (G_max), and average grain-filling rate (G_ave), thereby enhancing the effective spikes (ES) and grain number per spike (GS), and thus increased wheat grain yield (GY). In relative to W1, the W2, W3, and W4 treatments increased the ES, GS, and GY by 11.89–19.81%, 8.61–14.36%, and 8.17–13.62% across the three years. Notably, no significant difference was observed in GS and GY between W3 and W4 treatments, but W4 treatment displayed significant decreases in ES by 3.04%, 3.06%, and 2.98% in the respective years. The application of a structural equation modeling (SEM) revealed that deep storage irrigation improved ES and GS by positively regulating W_max, G_max, and G_ave, thus significantly increasing GY. Overall, this study identified the optimal threshold (W3 treatment) to maximize wheat yields by optimizing both the vegetative growth and grain-filling dynamics. This study provides essential support for the feasibility assessment of deep storage irrigation before flood seasons, which is vital for the balance and coordination of food security and water security. Full article

The accurate measurement of the tree diameter is vital for forest inventories, urban tree quality assessments, the management of roadside and railway vegetation, and various other applications. It also plays a crucial role in evaluating tree growth dynamics, which are closely linked to tree health, structural stability, and vulnerability. Although a range of devices and methodologies are currently under investigation, the widespread adoption of laser scanners remains constrained by their high cost. This study therefore aimed to compare high-end laser scanners (Trimble TX8 and GeoSLAM ZEB Horizon) with cost-effective alternatives, represented by the Apple iPhone 14 Pro and the LA03 scanner developed by mapry Co., Ltd. (Tamba, Japan). It further sought to evaluate the feasibility of employing these more affordable devices, even for small-scale forest owners or managers. Given the growing availability of 3D-based forest inventory algorithms, a selection of such processing pipelines was used to assess the practical potential of the scanning devices. The tested low-cost device produced moderate results, achieving a tree detection rate of up to 78% and a relative root mean square error (rRMSE) of 19.7% in diameter at breast height (DBH) estimation. However, performance varied depending on the algorithms applied. In contrast, the high-end mobile laser scanning (MLS) and terrestrial laser scanning (TLS) systems outperformed the low-cost alternative across all metrics, with tree detection rates reaching up to 99% and DBH estimation rRMSEs as low as 5%. Nevertheless, the low-cost device may still be suitable for scanning small sample plots at a reduced cost and could potentially be deployed in larger quantities to support broader forest inventory initiatives. Full article

Curcuma spp. is a popular ornamental crop valued for its vibrant appearance and suitability for both regular and off-season production. As global emphasis on freshwater conservation increases and with a demand for compact potted plants, reducing water use while maintaining high aesthetic quality presents a key challenge for horticulturists. Potassium silicate (PS) has been proposed as a foliar spray to alleviate plant water stress. This study aimed to evaluate the effects of PS on growth, ornamental traits, and photosynthetic parameters of off-season potted Curcuma cv. ‘Jasmine Pink’ under deficit irrigation (DI). Plants were subjected to three treatments in a completely randomized design: 100% crop evapotranspiration (ETc), 50% ETc, and 50% ETc with 1000 ppm PS (weekly sprayed on leaves for 11 weeks). Both DI treatments (50% ETc and 50% ETc + PS) reduced plant height by 7.39% and 9.17%, leaf number by 16.99% and 7.03%, and total biomass by 21.13% and 20.58%, respectively, compared to 100% ETc. Notably, under DI, PS-treated plants maintained several parameters equivalent to the 100% ETc treatment, including flower bud emergence, blooming period, green bract number, effective quantum yield of PSII (ΔF/Fm′), and electron transport rate (ETR). In addition, PS application increased leaf area by 8.11% and compactness index by 9.80% relative to untreated plants. Photosynthetic rate, ΔF/Fm′, and ETR increased by 31.52%, 13.63%, and 9.93%, while non-photochemical quenching decreased by 16.51% under water-limited conditions. These findings demonstrate that integrating deficit irrigation with PS foliar application can enhance water use efficiency and maintain ornamental quality in off-season potted Curcuma, promoting sustainable water management in horticulture. Full article

This study was performed to investigate the effects of dietary yeast culture (YC) supplementation on growth performance, digestive function, intestinal inflammatory response, and microbiota composition of largemouth bass Micropterus salmoides (LMB). Six diets were formulated with graded levels of YC (0, 5, 10, 15, 20, and 30 g/kg), referred to as CON, YC5, YC10, YC15, YC20, and YC30, respectively. Each diet was assigned to four replicate tanks of LMB juveniles (initial body weight 8.11 ± 0.05 g) with twenty fish per tank. After an 8-week feeding trial, final body weight and specific growth rate showed an increasing trend with 5~20 g/kg YC and reached a maximum at 15 g/kg YC. Feeding ratio decreased, but feed efficiency ratio (FER) improved in response to dietary YC inclusion, and FER was higher in the YC10 fish than in the YC5, YC20, and YC30 fish. Proximate composition (moisture, protein, and lipid) of the whole fish was not affected by dietary YC levels. The activities of intestinal lipase and trypsin were higher in the YC10 fish, while the relative expression of interleukin-8 (il-8) and il-1β was downregulated in the hindgut of the YC15 fish compared with the CON fish. Histological examination showed that the villus height of the midgut, together with goblet cell density of the foregut and midgut, was higher in the YC10 and YC30 fish than in the CON fish. 16S rRNA sequencing showed that Proteobacteria, Fusobacteria, and Firmicutes dominated the intestinal microbiota in LMB. The decrease in harmful Mycoplasma accounted for the dramatic change in Firmicutes abundance, while the increase in Cetobacterium (specifically C. somerae) accounted for the change in Fusobacteria abundance in the gut of the YC10 and YC30 fish compared with the CON fish. The increase in the beneficial Endozoicomonas was the main reason for the change in Proteobacteria abundance in the intestine of the YC30 fish as compared with the CON fish. Taken together, the alteration of intestinal microbiota composition contributed to the improved digestive function and feed utilization in LMB fed YC-supplemented diets. Based on growth performance, the optimal YC level in the diet for LMB was 15 g/kg. Full article

The re-establishment of submerged macrophytes is crucial for the ecological restoration of eutrophic lakes. Water depth (light intensity) and sediment nutrient levels are key factors influencing the growth of these macrophytes. Although their individual impacts have been extensively studied, their interactive effects remain unclear. We conducted a two-factor experiment to investigate the interactive effects of different water depths (50 cm and 190 cm) and sediment nutrient levels (fertile and infertile) on the growth and morphological traits of Vallisneria denseserrulata. We found that biomass, relative growth rate, below/above-ground biomass, ramet number, and leaf number significantly increased with decreasing water depth in fertile sediments, while no significant or less pronounced changes occurred for infertile sediments. The absence or weak responses to increased light intensity in infertile sediments are likely due to photoinhibition, which may be alleviated at higher nutrient levels in fertile sediments. Additionally, V. denseserrulata, in adapting to low-light environments (deeper water), increased plant height at the cost of decreased leaf number and below-ground biomass as water depth increased in fertile sediments. Our study demonstrated significant interactive effects between water depth (light intensity) and sediment nutrient levels on the growth and morphological traits of V. denseserrulata, indicating that their response to water depth (light intensity) strongly depends on sediment fertility. Full article

With increasing emphasis on sustainable horticulture, optimizing substrate composition is essential to reduce peat usage in container production. This study evaluated the effects of biochar and compost amendments on the growth and nutrient status of cherry laurel (Prunus laurocerasus) in two separate experiments conducted over five months. Experiment I assessed growth in pure peat and in peat–compost blends at volume ratios of 100:0, 70:30, 50:50, 30:70 and 0:100. Experiment II investigated the effect of adding biochar to a pure peat substrate at rates of 3 g·dm⁻³ and 5 g·dm⁻³. Key parameters were monitored, including the above and below-ground biomass, leaf and shoot counts, chlorophyll content, and the chemical composition of plant tissue and substrate. Compost addition increased the substrate pH from ~4.6 to ~6.4, while electrical conductivity increased with a higher compost content, reaching values approximately 2–3 times greater than in pure peat. Nutrient levels (Ca, K, Mg, P, NO₃⁻) also rose consistently with an increasing compost share. While a higher compost content generally reduced the biomass, leaf and shoot number, the greatest plant height and relatively favorable biomass were observed at 30% and 50% compost mixtures. Biochar addition slightly increased plant height, while the total biomass, root mass, and shoot number tended to decrease compared to pure peat, particularly at the lower biochar dose (3 g·dm⁻³). The substrate pH remained relatively stable, whereas electrical conductivity (EC) showed a slight upward trend with increasing biochar levels. Biochar also slightly increased the substrate nutrient content (Ca, K, Mg, P, NO₃⁻). Full article

Ozonated oils have promise as biostimulants, positively affecting physiological processes that promote plant growth and biomass accumulation. However, additional research is required to clarify their mechanisms of action, optimize dosages, and define effective application strategies. This study aimed to evaluate the biostimulant effect of three concentrations of two oils, avocado (Persea maricana Mill cv Hass) (50, 100, and 200 meqO₂ kg⁻¹) and high-oleic palm (Elaeis guineensis Jacq.) (5, 10, and 20 meqO₂ kg⁻¹), on the “Bolo Verde” squash Cucurbita moschata. The experiment followed a completely randomized design with a three-factor factorial arrangement: Factor I—type of ozonated oil; Factor II—application concentration (low, medium, and high); Factor III—application method (drench or foliar). The trial consisted of 15 experimental units, each with 32 plants, totaling 480 plants. Data were analyzed using SAS software. A one-way ANOVA was performed, and means were compared using Tukey’s test p ≤ 0.05. The drench application of high-concentration ozonated avocado oil (200 meqO₂ kg⁻¹) produced the most favorable biostimulant response, significantly increasing plant height, leaf number, root length, root volume, and total dry weight. This was followed by the drench application of low-concentration ozonated high-oleic palm oil (5 meqO₂ kg⁻¹), which yielded the highest dry matter accumulation. For the net assimilation rate (NAR) and leaf area index (LAI), the drench application of ozonated avocado oil at a high concentration resulted in 4.29 g cm⁻² day⁻¹ NAR and 7957.99 LAI, while low-concentration high-oleic palm oil recorded 4.36 g cm⁻² day⁻¹ NAR and 7208.40 LAI. Both treatments showed statistically significant differences (p < 0.05) compared to the control 2.35 g cm⁻² day⁻¹ NAR and 6780.24 LAI, indicating improved photosynthetic efficiency and leaf expansion. Similar trends were observed for crop growth rate (CGR) and relative growth rate (RGR). The drench application of high-concentration ozonated avocado oil yielded a CGR of 6.77 × 10⁻⁴ g cm⁻² day⁻¹ and RGR 0.0441953 g g⁻¹ day⁻¹. Low-concentration high-oleic palm oil drench application resulted in the highest CGR of 7.35 × 10⁻⁴ g cm⁻² day⁻¹ and RGR 0.0454216 g g⁻¹ day⁻¹. These values were significantly higher than those of the control (CGR 4.14 × 10⁻⁴ g cm⁻² day⁻¹; RGR 0.0357569 g g⁻¹ day⁻¹). These results suggest that the drench application of ozonated oils not only enhances photosynthesis and leaf growth but also favors the incorporation and accumulation of biomass in “Bolo Verde” squash. Full article

The determination of an optimal nitrogen (N) fertilization rate is critical for the sustainable large-scale cultivation of Cinnamomum camphora var. linaloolifera for essential oil production. Both suboptimal and excessive nitrogen inputs can adversely affect plant sustainable development and essential oil biosynthesis, underscoring the necessity of precise nutrient management. This study investigated the effects of five N application rates (0, 45, 90, 135, and 180 kg·hm⁻²) on vegetative growth, essential oil yield, and quality. Growth parameters, including plant height, basal diameter, specific leaf area (SLA), and essential oil yield and yield rate. Oil composition was characterized via gas chromatography–mass spectrometry (GC-MS). The application of 90 kg·hm⁻² N significantly enhanced plant height (74.31%), basal diameter (54.95%), SLA (20.91%), and biomass (181.8%) relative to the nitrogen-free control. Nitrogen uptake was concentrated in foliar tissues, accounting for 82.8% of total plant nitrogen accumulation. This fertilization rate also maximized essential oil yield (9.15 g·plant⁻¹) and yield rate (2.44%), reflecting increases of 178.9% and 24.49%, respectively. Linalool was the predominant oil constituent (89.84–91.81%), with its highest concentration observed at the 90 kg·hm⁻² treatment. At this rate, the relative abundance of oxygenated compounds increased by 0.97%, while hydrocarbon content decreased by 0.62%, indicating a qualitative improvement in oil composition. The findings reveal a threshold response to nitrogen input, wherein rates exceeding 90 kg·hm⁻² did not confer further benefits and may reduce efficiency. Collectively, these results suggest that a nitrogen application rate of 90 kg·hm⁻² optimally enhances vegetative growth, nitrogen assimilation, and both the quantitative and qualitative traits of essential oils in C. camphora var. linaloolifera. Full article

This study reviews the melting rate of anthropogenic snow patches formed as a result of cleaning the territory of Yuzhno-Sakhalinsk city from snow and collecting it in designated areas known as snow dumps. Snow patches persisted at absolute altitudes of less than 50 m in the summers during the period of 2010–2022, except in 2017. The positive factor was the ratio of the relatively small area occupied by the anthropogenic snow patch and its significant height at the beginning of the melting period. The detailed observations of anthropogenic snow patch growth and melting were conducted by the authors starting in the winter season of 2017–2018. The snow volume collected in snow dumps during the winter season in Yuzhno-Sakhalinsk can reach 3000 m³. That is why it is necessary to determine how the anthropogenic snow patch will loosen the water through the warm season. Special models of anthropogenic snow patch melting do not exist. So, the authors review the ability of four glacier and snow cover melting model applications for such objects. The contribution of various parameters affecting the snow path melting rate was also determined. The collected factual data allowed for the development of empirical snow patch melting models. The largest errors resulting in the usage of reviewed models are related to the beginning (April) and ending (September–October) of the melting periods. Full article

In citriculture, inputs like water and fertilizer are applied through traditional basin methods, thereby incurring reduced use-efficiency. The response of conventional crop coefficient-based fertigation scheduling continues to be inconsistent and complex in its field implementation, thereby necessitating the intervention of sensor-based (Internet of Things; IoT) technology for fertigation scheduling on a real-time basis. The study aimed to investigate fertigation scheduling involving four levels of irrigation, viz., I₁ (100% evapotranspiration (ET) as the conventional practice), I₂ (15% volumetric moisture content (VMC)), I₃ (20% VMC), and I₄ (25% VMC), as the main treatments and three levels of recommended doses of fertigation, achieved by reappropriating different nutrients across phenologically defined critical growth stages, viz., F₁, F₂, and F₃ (conventional fertilization practice), as sub-treatments, which were evaluated through a split-plot design over two harvesting seasons in 2021–2023. Nagpur mandarin (Citrus reticulata Blanco) was used as the test crop, which was raised on Indian Vertisol facing multiple nutrient constraints. Maximum values for physiological growth parameters (plant height, canopy area, canopy volume, and relative leaf water content (RLWC)) and fruit yield (characterized by 9% and 5%, respectively, higher A-grade-sized fruits with the I₄ and F₁ treatments over corresponding conventional practices, viz., I₁ and F₃) were observed with the I₄ irrigation treatment in combination with the F₁ fertilizer treatment (I₄F₁). Likewise, fruit quality parameters, viz., juice content, TSS, TSS: acid ratio, and fruit diameter, registered significantly higher with the I₄F₁ treatment, featuring the application of B at the new-leaf initiation stage (NLI) and Zn across the crop development (CD), color break (CB), and crop harvesting (CH) growth stages, which resulted in a higher leaf nutrient composition. Treatment I₄F₁ conserved 20–30% more water and 65–87% more nutrients than the I₁F₃ treatment (conventional practice) by reducing the rate of evaporation loss of water, thereby elevating the plant’s available nutrient supply within the root zone. Our study suggests that I₄F₁ is the best combination of sensor-based (IoT) irrigation and fertilization for optimizing the quality production of Nagpur mandarin, ensuring higher water productivity (WP) and nutrient-use-efficiency (NUE) coupled with the improved nutritional quality of the fruit. Full article

Research was conducted at the Agricultural Experiment Station—Khan Krum, Northeast Bulgaria during the period of 2014–2017. The aim of the study is to investigate the suitability of selected hybrids No.20-181 and No.20-192, obtained by interspecific crossing ‘Polevka’ (Prunus cerasus L.) × ‘Compact Van’ (Prunus avium L.) as clonal rootstocks for sour cherries. The rootstocks were grafted in a nursery with the cultivars ‘M-15’, ‘Nefris’, ‘Fanal’ and ‘Schattenmorelle’. Prunus mahaleb seedlings were used as the standard for comparison. Characteristics determining growth, the quality of the planting material and the compatibility of the rootstocks with commercial cultivars were tested. The average grafting success rate reported in the spring of the analyzed cultivar–rootstock combinations varied as follows: P. mahaleb (83–90%), hybrid No.20-192 (87–91%) and hybrid No.20-181 (82–85%). The selected hybrid 20-192 (‘Argo 2’) rootstock produces relatively weaker growth than the mahaleb. Hybrid 20-181 (‘Argo 1’) is characterized by the weakest growth. Both tested rootstock hybrids produce planting material with standard trunk diameter and tree height. With the weak growth that rootstock 20-181 induces in the grafted cultivar and the drought tolerance observed in 20-192, it is appropriate to continue the study in an orchard. Full article

Wetlands are crucial ecosystems that provide a wide range of ecological services, such as water purification, flood control, and carbon sequestration, where the diversity of wetland plants is fundamental to maintaining these functions. Phragmites australis is a globally widespread wetland grass with a high genetic diversity, exhibiting strong intraspecific variation across environmental gradients. While both phenotypic plasticity and genetic variation are recognized drivers of plant adaptation, their relative importance in mediating the growth and decomposition traits of wetland plants remains debated. Here, we surveyed the growth and litter traits of two lineages (haplotypes) of P. australis in two common gardens in eastern China. The leaf litter of P. australis was also collected from the field in two provinces where the two common gardens are located. Microcosm experiments were carried out to explore the litter decomposition ability. We found that the common garden (growth environment) significantly affected the growth performance (shoot diameter and height), leaf litter stoichiometric traits (contents of N and P), and the leaf decomposition over 180 days. The N content in the leaf litter from the higher-latitude province of Liaoning was greater than that from the lower-latitude province of Shandong, regardless of whether it was collected from the field or the common garden. The litter N and P contents were the key factors affecting the decomposition during the 180-day experiment. However, we did not find the effects of lineage (genetic variation) on the variation of these traits. The climatic factors of the genotype origin were significantly correlated with the growth traits but not the litter traits or decomposition rates. The findings indicate that P. australis in eastern temperate China primarily adapts through phenotypic plasticity rather than genetic variation, which is crucial for wetland resilience in a changing climate. This study underscores the pivotal role of environmental factors and phenotypic plasticity in P. australis growth and decomposition, suggesting that conservation efforts should prioritize the local environment over genetic variation for effective wetland management. Full article

To address low productivity and water constraints in lucerne fields of China’s Gansu Yellow River Irrigation Region, this study optimized lucerne (Medicago sativa L.) cultivation through synergistic planting nitrogen regimes. A two-year field trial (2021–2022) evaluated three systems: ridge-furrow with ordinary mulch (PM), ridge-furrow with biodegradable mulch (BM), and conventional flat planting (FP), under four controlled-release N rates (0, 80, 160, 240 kg ha⁻¹). Multidimensional assessments included growth dynamics, dry matter yield, forage quality (crude protein [CP], acid/neutral detergent fiber [ADF/NDF], relative feed value [RFV]), and resource efficiency metrics (water use efficiency [WUE], irrigation WUE [IWUE], partial factor productivity of N [PFPN], agronomic N use efficiency [ANUE]). The results showed the following: (1) Compared with conventional flat planting, ridge planting with film mulching significantly promoted lucerne growth, with ordinary plastic film providing a stronger effect than biodegradable film. Plant height and stem diameter exhibited a quadratic response to elevated nitrogen (N) application rates under identical planting patterns, peaking at intermediate N levels before declining with further increases. (2) Ridge planting with both ordinary plastic film and biodegradable film combined with an appropriate N rate improved lucerne yield and quality. In particular, the PMN2 treatment reached the highest value of yield (14,600 kg ha⁻¹), CP (19.19%) and RFV (124.18), and the lowest value of ADF (29.63%) and NDF (48.86%), and all of them were significantly better than the other treatments (p < 0.05). (3) WUE, IWUE, PFPN, and ANUE followed the pattern PM > BM > FP. With increasing N application rates, WUE, IWUE, and ANUE initially rose and then declined, peaking under N2, whereas PFPN showed a decreasing trend and reached its maximum under N1. Principal component analysis revealed that ridge planting with ordinary plastic film combined with 160 kg·ha⁻¹ N (PMN2) optimized lucerne performance, achieving balanced improvements in yield, forage quality, and water–nitrogen use efficiency. This regimen is recommended as the optimal strategy for lucerne cultivation in the Gansu Yellow River Irrigation Region and analogous ecoregions. Full article

Forests are invaluable natural resources that provide essential ecosystem services, and their carbon storage capacity is critical for climate mitigation efforts. Quantifying this capacity would require accurate estimation of forest structural attributes for deriving their aboveground biomass (AGB). Traditional field measurements, while precise, are labor-intensive and often spatially limited. Handheld Mobile Laser Scanning (HMLS) offers a rapid alternative for building forest inventories; however, its effectiveness and accuracy in diverse subtropical forests with complex canopy structure remain under-investigated. In this study, we employed both HMLS and traditional surveys within structurally complex subtropical forest plots, including old-growth forests (Fung Shui Woods) and secondary forests. These forests are characterized by dense understories with abundant shrubs and lianas, as well as high stem density, which pose challenges in Light Detection and Ranging (LiDAR) point cloud data processing. We assessed tree detection rates and extracted tree attributes, including diameter at breast height (DBH) and canopy height. Additionally, we compared tree-level and plot-level AGB estimates using allometric equations. Our findings indicate that HMLS successfully detected over 90% of trees in both forest types and precisely measured DBH (R² > 0.96), although tree height detection exhibited relatively higher uncertainty (R² > 0.35). The AGB estimates derived from HMLS were comparable to those obtained from traditional field measurements. By producing highly accurate estimates of tree attributes, HMLS demonstrates its potential as an effective and non-destructive method for rapid forest inventory and AGB estimation in subtropical forests, making it a competitive option for aiding carbon storage estimations in complex forest environments. Full article

Plant growth, a fundamental biological process that underpins terrestrial ecosystem function, is susceptible to nutrient availability. Despite extensive research on lowland ecosystems, the responses of alpine plant growth to nutrient addition remain poorly understood, particularly given the heightened sensitivity of alpine ecosystems to global change. To investigate the effects of nitrogen (N) and phosphorus (P) additions on the growth rates of alpine plants and the underlying mechanisms of how these nutrient additions influence plant growth rates, we conducted an experiment in an alpine grassland on the Qinghai–Tibet Plateau, targeting 14 common plant species. Growth rates were measured using biomass and height, with plant height and soil physicochemical properties recorded biweekly during the growing season. We assessed the effects of nitrogen and phosphorus additions on growth rates, their seasonal dynamics, and their relationships with soil physicochemical properties. Results showed that phosphorus addition and combined nitrogen-phosphorus additions significantly increased the relative growth rate based on height (RGR_H). In contrast, nutrient additions had no significant effect on the relative growth rate based on biomass (RGR_B). RGR_H decreased from June and early July to August, exhibiting species-specific responses to nutrient additions. Additionally, RGR_H was significantly influenced by the interaction of nitrogen and phosphorus additions, species, and seasonal dynamics (p < 0.05). Soil available N, available P, and moisture were significantly positively correlated with RGR_H (p < 0.05), while soil temperature (ST), total nitrogen (TN), and soil organic carbon (SOC) exhibited significant negative correlations (p < 0.05). Nutrient additions altered the hierarchy, as well as the direct and indirect factors that influence RGR_H, revealing the opposing regulatory effects of total and available nitrogen. These findings highlight the critical roles of nitrogen and phosphorus, suggesting phosphorus is a potential limiting factor for plant growth in this alpine region. This study offers a comprehensive analysis of how nitrogen and phosphorus additions affect alpine plant growth rates and clarifies the underlying mechanisms in these sensitive ecosystems. Full article