Plant Management Research Articles

SC-ResNeXt: A Regression Prediction Model for Nitrogen Content in Sugarcane Leaves

In agricultural production, the nitrogen content of sugarcane is assessed with precision and the economy, which is crucial for balancing fertilizer application, reducing resource waste, and minimizing environmental pollution. As an important economic crop, the productivity of sugarcane is significantly influenced by various environmental factors, especially nitrogen supply. Traditional methods based on manually extracted image features are not only costly but are also limited in accuracy and generalization ability. To address these issues, a novel regression prediction model for estimating the nitrogen content of sugarcane, named SC-ResNeXt (Enhanced with Self-Attention, Spatial Attention, and Channel Attention for ResNeXt), has been proposed in this study. The Self-Attention (SA) mechanism and Convolutional Block Attention Module (CBAM) have been incorporated into the ResNeXt101 model to enhance the model’s focus on key image features and its information extraction capability. It was demonstrated that the SC-ResNeXt model achieved a test R2 value of 93.49% in predicting the nitrogen content of sugarcane leaves. After introducing the SA and CBAM attention mechanisms, the prediction accuracy of the model improved by 4.02%. Compared with four classical deep learning algorithms, SC-ResNeXt exhibited superior regression prediction performance. This study utilized images captured by smartphones combined with automatic feature extraction and deep learning technologies, achieving precise and economical predictions of the nitrogen content in sugarcane compared to traditional laboratory chemical analysis methods. This approach offers an affordable technical solution for small farmers to optimize nitrogen management for sugarcane plants, potentially leading to yield improvements. Additionally, it supports the development of more intelligent farming practices by providing precise nitrogen content predictions.

Ethnobotany of vascular plants use, conservation and management practice in the homegardens by the people of Dawuro in Southwestern Ethiopia

BackgroundHomegardens (HGs) are well-time-honored traditional land use systems in small plots of land with purposely designed intricate structure and a mixture of planted vascular plants (VPs) for different purposes. Hence, the present study was initiated to investigate the ethnobotanical information of vascular plants of homegardens and their use, conservation and management practice by the people of Dawuro in southwestern Ethiopia.MethodsA total of 162 farmer informants were selected and interviewed within a distance of < 2 km, 2–4 km and > 4 km between the natural forest and homegardens, and 0.8–1 km between the homegardens. Quadrats of three 5 m × 10 m were laid (except front yard) around each living houses. Shannon–Wiener diversity index was used for analysis of diversity.ResultsThere were 345 vascular plants in the homegardens distributed in 252 genera and 79 families. The most frequently recorded plant families were Fabaceae with 38 (11%), Asteraceae 33 (10%), and Lamiaceae 26 (7.5%). The species richness recorded per homegardens ranged from 13 to 59. Ensete ventricosum, Persea americana, Colocosia esculenta, Coffea arabica, Solanum capsicoides, and Ocimum basilicum were the most frequently occurred species. The homegarden was enset-based agrobiodiversity system providing food, medicine and other uses where the highest, 290 species were for medicine. Men are responsible for planting and propagating large-sized plant species in the homegardens, while small-sized were managed by women and children. The α-diversity (H’) ranged from 1.4 to 3.4 and the gamma diversity was 4.2. Culture has positive effect on diversity however, the diversity of species is affected by distance from natural forest (x2 = 14.825, df = 4, p = 0.005) at P < 0.05 level.ConclusionAwareness raising designed and executed by farmer experts and researchers focusing on managing homegarden is necessary to fill the observed gaps in knowledge and attitude of the new generation. The enset-based homegarden management knowledge and practice as well as avoiding the diseases and other constraints of enset should be given attention. Furthermore, decisions on avoiding the growth and management of invasive exotic plant species like eucalyptus tree in the homegardens have to be made.

Improving Evaluation Systems for Public Institution Performance: A Case Study of Regional Cooperation at the Korea National Arboretum

This study addresses the deficiency in performance indicators of public institution arboretums and highlights the increasing need for collaborative cooperation for mutual growth. We aim to develop both quantitative and qualitative performance indicators to improve the evaluation systems and optimize operational efficiency. Initial indicators were formulated based on a review of 31 literature sources, followed by focus group interviews and a Delphi analysis involving 21 experts. A total of 23 core indicators were identified and categorized into three domains: public interest, economics, and functional aspects. Public interest indicators included seven items focusing on co-growth indicators (four) and contributions to the arboretum and garden culture development (three). Economic indicators featured ten items, including those related to regional exhibitions (four) and regional economic activation (six). The functional aspects indicators comprised six items: outsourced cultivation (three) and plant management (three). The highest-priority indicator was related to regional economic activity (income generation for local small business owners). Recommendations should be tailored to each department to bolster organizational performance, strengths, and capabilities. We anticipate that these indicators will support the mutual growth of national arboretums and local farming communities in Korea.

Response of Understory Plant Diversity to Edge Effects in Plantation Forests on the Loess Plateau

The majority of the world’s forests are located at landscape edges and are highly fragmented; the plantations on the Loess Plateau are no exception, experiencing pronounced edge effects. However, edge effects are often overlooked in assessments of carbon storage and biodiversity, and the extent and impact of these effects on Loess Plateau plantations remain inadequately understood. The objective of this study is to reveal how edge effects influence biodiversity and species composition and to examine their long-term impacts on ecosystem structure and function. Furthermore, it aims to explore the mechanisms underlying edge effects in plantation systems. Examining these effects is essential for guiding forest management practices and formulating effective biodiversity conservation strategies, thereby providing scientific insights to support the ecological restoration and sustainable management of plantations. In this study, we classified 44 sample plots into four groups according to their distances from the plantation edges to compare and analyze species composition. Additionally, we evaluated the intensity and range of edge effects on stand structure, species diversity, and carbon storage. The Shannon index of understory vegetation was used as the dependent variable, with canopy cover, edge distance, and stand density as independent variables. We used multiple linear regression to examine the effects of these factors on the Shannon index of understory vegetation (shrubs, herbs, and trees). The key findings were as follows: (1) Tree height did not exhibit edge effects across any distance range, while the Shannon index, species richness, and carbon storage showed edge effects within 54 m from the edge. Diameter at breast height (DBH), stand density, and canopy cover exhibited edge effects within 0–83 m from the edge. (2) The significance values for edge distance and canopy cover in the linear regression with the Shannon index were 0.99 and 0.51, respectively, showing no significant correlation. In contrast, stand density had a significant positive effect on the Shannon index (p = 0.03). (3) Notable differences in understory species composition were observed between the outermost and innermost groups of the plantation. Climatic conditions on the Loess Plateau exert a dominant influence on understory plants, altering species composition and abundance. High stand density appeared to moderate the microclimate, contributing to a higher understory Shannon index, but reducing carbon storage. Our findings suggest that the edge effects of plantation forests on the Loess Plateau exert varying degrees of influence on different indicators. Management decisions should be guided by the specific silvicultural objectives, whether the manager’s goals are to optimize biomass accumulation, enhance species recovery, or achieve a balance between these two goals.

Impact of Job Satisfaction on the Young Community Engaged in the Plantation Jobs: Evidence from Sri Lanka

The plantation industry can be recognized as a sector that contributes greatly to the economy of Sri Lanka. However, it has been found that the labor shortage caused by the youth community leaving plantation jobs, especially in large-scale tea estates, has directly contributed to the decline in Sri Lanka’s tea production and export capacity. The main objective of this study is to identify the job satisfaction of the young people doing plantation jobs and its effect on the young community to leave the plantation jobs, about 106 young people working in the Spring Valley Tea Estate of Haliela Divisional secretariat, Badulla District, Sri Lanka were selected as a sample through stratified random sampling method. Primary data collection was done on the socio-economic data of the youth and their satisfaction with the internal factors of the job using questionnaires and interviews. Furthermore, Binary logistic regression model and Likert scale intervals were used for data analysis. According to research data, 78% of young people working on plantations are dissatisfied with their jobs. It was revealed that the internal factors of the job such as the low level of social acceptance of the job, the low salary paid by plantation management in comparison to alternative jobs, the inadequacy of basic facilities provided in the work environment, the weakness of residential facilities, problems in supervision, prolonged working hours, insufficient overtime and additional allowances have mainly affected to increasing job dissatisfaction of youth, and for they leaving from plantation employment. The binary logistic model revealed that there is a significant negative relationship between factors such as education level, age, and job satisfaction, and a significant positive relationship between daily income, service time, and job satisfaction. It was also possible to recognize that men are more likely to be satisfied with jobs compared to women. Accordingly, Measures such as providing formal training, adequate living wage, improving basic facilities in the work environment, providing quality residential facilities, developing job security, making a systematic and formal performance evaluation system, improving existing social recognition for plantation jobs, and introducing small-scale contract farming system (SCFS) to the youth in Plantation jobs can be recommended as the most appropriate measures that can be taken to prevent the youth working in tea estate from leaving the plantation jobs.

Research on the systematic architecture of nuclear safety management for nuclear power plants based on cloud platform

Research on the systematic architecture of nuclear safety management for nuclear power plants based on cloud platform

Tracing the trail of eroded fertile soils during a high intensity rainfall event: A fingerprinting study in war-torn tropical mountains

The depletion of fertile topsoil presents a critical challenge in tropical mountain agroecosystems. Impacts are intensified during heavy storm events that strip unprotected topsoils and pose risks to downstream water ecosystems. To better understand such dynamics, we investigated an agricultural mountainous catchment located on the Democratic Republic of the Congo shore of Lake Kivu. This area is characterised by weak governance systems exacerbated by protracted violent conflicts, which have prevented the application of remediation practices to address extensive land use changes, including deforestation and monoculture proliferation, notably banana plantations. Additionally, the spread of Banana Xanthomonas wilt (BXW) has further augmented land use impacts. Herein the complete diseased mat uprooting (CDMU) method employed to combat the disease has resulted in significant erosion and sediment export rates. Following the recovery of banana plantations from CDMU, sediment export rates continued to increase without a clear responsible party but more as a legacy of past and present land degradation activities and embedded soil erosion and connectivity process pathways. To analyse the impact of high-intensity storm events coupled with the aftermath of conflict instability and the effects of BXW on erosion dynamics, the sediment fingerprinting technique was implemented. We collected 60 sediment source samples across a 42km2 catchment, predominantly cultivated since the mid-20th century. Samples spanned four main land uses/land covers: seasonal crops, banana plantations, bare or degraded soil, and channel banks. Additionally, mixture/target samples were collected at the summit of six fluvial terraces located at different altitudes along the vertical profile of the river after a high-intensity storm event. These terraces serve as natural indicators of sediment accumulation under different flow intensities, with higher terraces representing sediment deposition during higher discharge. Furthermore, sediment samples were collected via a gravity core in delta deposits at the river's inflow into the lake, allowing us to identify the main sources contributing to fine sediment export to the lake. This methodology enabled us to assess how sediment provenance has changed in response to varying discharge levels while elucidating the primary sources responsible for fine sediment inputs to the lake and the subsequent water quality decrease. Our analysis indicates increased contributions occurred from channel banks and degraded areas as discharge increased. Despite steep channel banks and degraded soils being primary sediment sources on the terraces, agricultural and banana sources predominantly contributed to the fine sediments exported to the lake. These findings underscore the hazards of high-intensity storm events in these fragile ecosystems and highlight the role of current banana plantation and cropland management in degrading land and water quality. Understanding the primary factors driving land degradation and sediment export is crucial for preventing further ecosystem degradation and mitigating heightened instability in conflict-affected areas. This research suggests that remediation practices should be incentivised to create buffer structures in upslope agricultural areas and protect the fertile sediments from banana plantations from being exported to the lake if socio-cultural and economic hurdles to implementation can be overcome.

Modeling Biological Nutrients Removal for Wastewater Treatment Plant (WWTP) Management: A Case Study of Ain El Houtz WWTP (Algeria)

AbstractThis study aimed to develop a comprehensive Ain El Houtz Wastewater Treatment Plant (WWTP) model that represents its biological nutrient removal process to simulate its performance and assess the model's predictability. Operational data was collected and analyzed over three years (2020 to 2023), to characterize the water quality of influent and effluent discharged from the plant. Physicochemical parameters such as Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), Ammonium-Nitrogen (NH4), Nitrite-Nitrogen (N-NO2−), Nitrate-Nitrogen (N-NO3−), and Phosphate ions (PO4-3) were considered. Using the GPS-X software modeling platform, a process flow diagram was developed to integrate the ASM2d model for biological nutrient removal. Through the sensitivity analysis of kinetic and stoichiometric parameters, the research identified the key parameters that impacted the nutrient removal efficiency, which in turn further guided the calibration process. The calibration adjustments focused primarily on parameters associated with denitrification, autotrophic growth, and oxygen saturation coefficients. Statistical measures such as Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE) were used to evaluate the model’s performance in both steady-state and dynamic-state validation scenarios. Results indicated that for the steady state the MAE and RMSE were the same, NH4 (6.06) N-NO2−&amp; N-NO3− (1.36), and PO4-3 (3.167), while for dynamic-state we noticed a difference between the MAE and RMSE for the concentration, indicating the complexity of modeling nutrient removal processes. It was observed that PO4−3 concentration was not affected by the sensitivity analysis, possibly due to the lack of availability of specific process for the phosphorus removal in the treatment plant, further studies are needed to be carried out to address this issue in detail.

FARMER GROUP EMPOWERMENT THROUGH THE FIELD SCHOOL OF INTEGRATED PLANT-MANAGEMENT (SL-PTT) PROGRAM IN BERU-BERU VILLAGE KALUKKU DISTRICT MAMUJU REGENCY

Developing the food crops sector is one of the key strategies to stimulate future economic growth. Besides being a major source of foreign exchange, this sector is the source of life for most of the Indonesian population. The increasing population has raised concerns over the state of "food insecurity" in the future. Therefore, to meet the food needs in the West Sulawesi province, the Department of Agriculture and Livestock initiated the Field-School of Integrated Plant Management (SL-PTT) program. This study is entitled "FARMER GROUP EMPOWERMENT THROUGH THE FIELD-SCHOOL OF INTEGRATED PLAN-MANAGEMENT (SL-PTT) PROGRAM IN BERU BERU VILLAGE KALUKKU DISTRICT MAMUJU REGENCY". The implementation of this program faces some issues such as the model applied in the program, the factors influencing the production and income, and the development pattern. This study aims to identify the implementation of the SL-PTT program in Beru-Beru Village including the inhibiting factors. This study was conducted in Beru-Beru Village, Kalukku District, Mamuju Regency. This study used a descriptive method with a qualitative approach. Data collection techniques covered observations, interviews, and documentation. Based on the results of the observation, the SL-PTT program has been successfully implemented. In practice, it manages to achieve the predetermined targets and objectives as well as involve farmers to participate in the improvement of agricultural yields. The inhibiting factors in the implementation of this program, include no response from the government for farmer groups who implement the SL-PTT program, lack of farmer group administrator effort to hold the counseling group meetings, different levels of soil fertility, different economic capabilities, unprepared use of agricultural technologies, and the limited budget allocation. Considering those challenges, the government of West Sulawesi province is expected to help increase the budget allocation for the implementation of this program, recruit the mentoring team based on technical competence aspects, and give insight to the community about the SL-PTT program.

Strategic asset management in LNG Plants: A holistic approach to long-term planning, rejuvenation, and sustainability

The liquefied natural gas (LNG) industry plays a vital role in the global energy landscape, balancing growing energy demands with the imperative of reducing environmental impacts. However, the sector faces significant challenges, including aging infrastructure, the need for operational efficiency, and adherence to sustainability goals. This paper explores the role of strategic asset management (SAM) as a holistic solution for optimizing LNG plant operations. It introduces a comprehensive framework that integrates organizational, financial, and technical strategies, emphasizing long-term planning, rejuvenation, and sustainability. Key strategies, such as predictive maintenance, digital twins, and risk-based inspection methods, are discussed for their effectiveness in extending asset lifecycles and minimizing downtime. Furthermore, the paper underscores the importance of environmental, social, and governance (ESG) factors, renewable energy integration, and resilience planning in addressing climate risks and market volatility. Concluding with actionable recommendations, this paper provides a roadmap for stakeholders to adopt SAM practices, ensuring sustainable, resilient, and competitive LNG operations. Keywords: Liquefied Natural Gas, Strategic Asset Management, Sustainability, Predictive Maintenance, Digital Twin Technology, Resilience Planning.

Green synthesis and characterization of CuO nanoparticles derived from Pimenta dioica and evaluating its activity against Tobacco streak virus

The synthesis of nanoparticles using plants represents a green and sustainable method that uses natural and non-toxic resources for nanoparticle production. In this study, CuO nanoparticles were synthesized from allspice (Pimenta dioica ), which served as both the capping and reducing agent during synthesis. Synthesised nanoparticles were validated using UV-Vis spectroscopy, X-ray diffraction, FT-IR analysis and Transmission Electron Microscopy (TEM). The monoclinic phase of the synthesised particles was revealed through the X-ray diffraction pattern indicating its crystalline nature. The UV -visible spectrum showed a strong absorbance of UV rays at a wavelength of 294 nm, confirming the presence of CuO nanoparticles. FT-IR analysis identified different functional groups from the phytochemicals in the plant extract used for the green synthesis, with peaks at 424.34 cm-1, 478.35 cm-1, 555.50 cm-1 and 648.08 cm-1 corresponding to Cu-O bond vibrations, thereby confirming the existence of CuO nanoparticles. TEM analysis revealed that the nanoparticles had spherical and hexagonal shapes, with sizes ranging from 10 to 20 nm. The antiviral potential of these nanoparticles was assessed against Tobacco streak virus, isolated from black gram plants, as spray applications at concentrations of 100, 200, 400 and 500 ppm. The preinoculation spray at 500 ppm of CuO nanoparticles, followed by challenge inoculation with the virus, yielded the most effective result, with a reduction of 59.58 % compared to the control. Therefore, the antiviral efficacy of synthesized CuO nanoparticles against plant viruses was established, supporting their potential as a novel strategy for plant management.

Ultrafine industrial aerosol as an occupational risk factor for sintering industry workers

Aim. Assessment of the physicochemical characteristics of suspended particulate matter of the ultrafine range present in the air of the working area of the sintering factory of a metallurgical plant. Materials and methods. The assessment and analysis of the physicochemical parameters of ultrafine particles were carried out in different areas of the sintering factory of the metallurgical plant. The parameters were measured using a portable scanning spectrometer Nanoscan 3910 (USA). The chemical composition of the suspended particulate matter was determined by the method of optical emission spectrometry with inductively coupled plasma (OES-IZP) using the device “Ortima 2100 DV” (PerkinElmer, USA). Results. It was estimated that the concentration of suspended particulate matter of ultrafine size in the main part of the sintering machine ranged from 3.02 × 104 to 3.12 × 104 per cm3, in the tail part of the sintering machine – from 5.09 × 104 to 7.59 × 104 per cm3, in the sintering machine control room No. 1 – from 2.06 × 104 to 2.38 × 104 per cm3, in the workers of the control group – from 1.43 × 104 to 1.73 × 104 per cm3. The quantitative concentration of suspended particulate matter by individual sizes at all workplaces of the sinter plant workers compared to workers of the control group had a significant difference. Values of the total surface area and surface volume of suspended particulate matter of the nano-sized range had their maximum in the tail part and near the head of the sintering machine, the lowest values were recorded around the control room and among the employees of the plant management department. The highest mass concentration of ultrafine particles was recorded in the tail part of the sintering machine (22.55 μg/m3 to 508.35 μg/m3), which is associated with a significant amount of suspended particulate matter of a larger size (≥115.5 nm). The chemical composition of the particles of the ultrafine range included aluminum, calcium, iron, magnesium, manganese, silicon, and phosphorus, which is explained by the specifics of the technological process, and the exceeding of the hygienic standard was observed for calcium, silicon and phosphorus. Conclusions. It was established that during the sintering of the agglomerate in the agglomeration compartment, many suspended particles of the ultrafine range are formed. They included aluminum, iron, manganese, magnesium, silicon, phosphorus, and calcium. Significantly higher values of the number, mass concentration, surface area and surface volume of suspended particulate matter were determined at the workplaces of sintering factory workers, which had a statistically significant difference compared to the workers of the control group.

The effect of silicon supplementation and drought stress on the deposition of callose and chemical components in the cell walls of the Brassica napus roots.

Silicon has an important role in regulating water management in plants. It is deposited in cell walls and creates a mechanical barrier against external factors. The aim of this study was to determine the role of silicon supplementation in the synthesis and distribution of callose in oilseed rape roots and to characterize the modifications of cell wall structure of these organs after exposure to drought stress. Histological and ultrastructural analyses were performed to determine the changes in the distribution of arabinogalactan proteins, pectins, and extensin in roots of Brassica napus growing under drought and supplemented with silicon. Callose deposition and the accumulation of callose synthase protein were assessed, followed by transcriptional analysis of callose synthase genes. The results showed that silicon supplementation under drought conditions alter the direction of cortex cell differentiation, promoting fiber formation and proliferation of callose-depositing cells in the roots of the tested plants. This was reflected in an increase in the level of callose synthase and a decrease in the transcriptional activity of the gene encoding this enzyme, indicating regulation based on negative feedback under drought stress. The changes in abundance and distribution of investigated arabinogalactan proteins, pectins and extensin in roots of Si supplemented plants growing under drought stress were observed, indicating cell walls remodeling. Silicon supplementation in oilseed rape roots induced significant changes in cell wall composition, including increased callose deposition and altered pectins and arabinogalactan proteins distribution. These modifications, along with the formation of fibres in the root cortex, likely contribute to enhanced cell wall strength providing a physical barrier against water loss and mechanical stress, as a probable defence mechanism induced during drought stress.

Establishing optimal nutrient level of magnesium and boron in black pepper for optimization of productivity in Western Ghats of Kerala

Critical nutrient level of magnesium and boron in soil and plant biomass of black pepper (Piper nigrum) have been estimated in Western Ghats of Kerala by conducting field experiments in three seasons (2018-2020) by magnesium and boron fertilization. Nutrient management in black pepper plantations wins important value due to its wider use as spice all over the world. As black pepper plants are easily prone to Mg and B deficiency, its response to Mg in the form of magnesium sulphate and B as borax was evaluated in terms of yield, plant nutrient content and nutrient status in soil. Effect of Mg as well as B application on the other available nutrients and leaf nutrient content were also determined in the study. Response curves were fitted by plotting relative yield of black pepper with Mg and B in soil and index leaf. The graphical method of Cate and Nelson was used to derive the optimal concentrations of nutrients. The critical levels of magnesium in soil and black pepper leaves were established as 140 mg kg-1 and 0.44 % respectively. Optimum dose of magnesium sulphate for getting highest yield of black pepper was found as 120 kg ha-1 followed by MgSO4 @ 80 kg ha-1. Similarly critical limit of B in the soil and index leaf of black pepper were 0.58 and 21 mg kg-1 respectively. The maximum potential yield was obtained by applying boron as borax at 0.2% via foliar application and at a higher dosage of 2 kg per hectare through soil application.

Divergent Effects of Monoculture and Mixed Plantation on the Trade-Off Between Soil Carbon and Phosphorus Contents in a Degraded Hilly Land

Carbon (C) and phosphorus (P) in soil are closely related to plantation types in afforestation practices. However, the trade-off between soil C and P in response to different restoration models on degraded hilly land is still not clear. In this study, four restoration patterns, including natural recovered shrubland (NS), Castanopsis hystrix plantation (CH), 10-species mixed plantation (10MX), and 30-species mixed plantation (30MX) were selected, and the physicochemical properties and readily oxidized carbon (ROC) in different layers of 1 m depth soil were measured to understand the effects of natural restoration and artificial afforestation on soil P and C pool and their trade-off on degraded hilly land in southern China. The results indicate that the total P (TP) content in each soil layer was observed to follow the order of CH &gt; 10MX &gt; 30MX &gt; NS, with monoculture (CH) exhibiting higher levels of TP than mixed plantation. However, the soil C storage of NS (59.61 t hm−2) and 30MX (57.71 t hm−2) was similar, while 10MX boasted the highest C storage (64.99 t hm−2) of the four restoration patterns, with CH being the lowest (42.75 t hm−2). In deep soil layers (20–100 cm), the 10MX plantation presented the highest for both the C pool index (CPI) and C pool management index (CMI). Moreover, the structural equation model (SEM) revealed that the soil CMI was directly regulated by the levels of soil available P and total N, while soil C pool activity was directly influenced by soil pH. Thus, our study suggests that compared to mixed plantations, the monoculture plantation (CH) demonstrates lower P uptake and utilization, resulting in a higher soil P content. Furthermore, 10MX plantation showed a superior C fixation capacity over those with 30MX and monoculture plantations. These suggests that the trade-off between soil C and P contents was commonly observed among different plantation restoration patterns. Therefore, afforestation with different tree composition and nutrient regulation is necessary for maintaining the balance between soil C and P and keeping the sustainability of plantation management in the degraded hilly lands.

Analisis Hukum Terhadap Wanprestasi pada Perjanjian Kerjasama Pengelolaan Kebun Kelapa Sawit (Studi: PT. Tepian Gayor Langkat)

This study aims to analyze the implementation of the oil palm plantation management cooperation agreement at PT. The edge of Gayor Langkat, identifies the default that occurred, and evaluates legal remedies and legal consequences arising from the violation. This study uses a normative juridical approach with qualitative descriptive analysis based on literature studies and interviews. The data was analyzed to identify defaults, legal remedies, and consequences in the agreement of PT. The banks of Gayor Langkat. The results of the study show that the implementation of the cooperation agreement between PT. The banks of Gayor Langkat and Darmawan Armiadi were declared in default due to violations of Articles 3, 4, and 8 related to written approvals, financial statements, and profit sharing. The Second Party failed to fulfill its obligations, causing the First Party to lose Rp. 138,726,000. After legal remedies such as reprimands, summonses, and lawsuits, the court ruled on default, canceled the agreement, and sentenced the Second Party to pay damages of Rp200,000,000. This case emphasizes the importance of a strong agreement, strict supervision, and compliance to prevent losses and ensure fairness.

Dynamics of Soil N and P Nutrient Heterogeneity in Mixed Forest of Populus × Euramercana ‘Neva’ and Robinia pseucdoacacia in Coastal Saline–Alkali Land

The mixing of poplar and robinia in coastal saline land is a useful attempt at difficult site afforestation. Investigating the long–term mixing effects of nitrogen–fixing and non–nitrogen–fixing tree species on the spatial heterogeneity of N and P nutrients and their ecological stoichiometric characteristics in the coastal saline–alkali soil can provide a scientific basis for soil improvement and plantation management in the coastal saline–alkali soil. By replacing time with space, poplar and robinia mixed forests and corresponding pure forests with the ages of 3, 7 and 18 years were selected, and soil profiles of 0–20 cm, 20–40 cm and 40–60 cm were dug up to determine the contents of total nitrogen, hydrolyzed nitrogen, total phosphorus and available phosphorus, the activities of soil urease and phosphatase and the number of soil bacteria, fungi and actinomycetes in rhizosphere soil. The mixture of poplar and robinia and the increase in planting years led to the heterogeneity of soil N and P in a coastal saline–alkali forest, which could significantly increase the contents of soil total nitrogen, hydrolyzed nitrogen, total phosphorus and available phosphorus between soil layers. Compared with the pure forest of poplar and robinia at the same age, the soil urease activity in the 0–20 cm soil layer of an 18a poplar and robinia mixed forest increased by 94.75% and 73.36%, and the soil phosphatase activity increased by 30.36% and 70.27%. The mix of poplar and robinia significantly increased the abundance of soil microorganisms in saline–alkali soil. The number of bacteria, fungi and actinomycetes in the 0–20 cm soil layer of the 18a poplar and robinia mixed forest was the highest, which were 703,200, 31,297 and 1903, respectively. Redundancy analysis showed that there was a significant positive correlation between soil N and P nutrient contents, soil enzyme activities and microbial abundance. The soil depth of N and P nutrient decomposition and transformation in the mixed poplar and robinia plantation was expanded. The soil N and P nutrient contents, enzyme activities and microbial abundance in the 40–60 cm soil layer of the mixed forest were higher than those of the pure forest. With the increase in plantation years, the depth of soil that can be used in the forest land is increasing. The mixture of poplar and robinia plantation is an excellent choice for the construction of coastal saline–alkali land plantation, which has a significant mixed gain for the decomposition and transformation of N and P nutrients and increases the depth of the available soil layer in the forest land in coastal saline–alkali land. However, the coastal saline–alkali land soil N/P is &lt; 14 and is still restricted by nitrogen, so the application of nitrogen fertilizer can be increased during the afforestation process.

Plant biodiversity, vegetation structure and provisioning services in rainforest, traditional and industrial oil palm cultivation systems in Liberia, West Africa

Societal Impact StatementOil palm is native to the west African forest, where industrial production is expanding. We assessed differences in plant biodiversity, vegetation structure and provisioning services across 54 forest, community agriculture and oil palm plots in Sinoe County, Liberia. Traditional cultivation systems have lower ecological impacts in terms of species richness, composition, canopy height and structural complexity compared with industrial production, though yields per hectare are likely to be lower. Traditional systems can inspire improved management of industrial plantations, including choice of cover crop, intercropping with locally valued species and reduced clearance and pesticide regimes, increasing biodiversity and local food security.Summary Tropical agriculture contributes to national and global food security, but the conversion of natural habitats to agriculture has severe consequences for biodiversity, ecosystem functioning and society. Significant research efforts have focussed on improving the sustainability of palm oil production in Asia, but less research has been conducted in the African forest zone, where oil palm is native and production is expanding. Working within the Sustainable Oil Palm in West Africa (SOPWA) Project (Sinoe County, Liberia), we surveyed canopy trees and understorey plants in 54 plots distributed equally across three ecological systems ‐ rainforest, traditionally‐cultivated oil palm (“country palm”) and industrially‐managed oil palm ‐ to assess differences in plant biodiversity, vegetation structure and provisioning services. Traditionally‐cultivated oil palm systems had intermediate plant biodiversity (species richness, weighted endemism) and structure (canopy height, complexity) compared with industrial production or rainforest. Provisioning services (proportion of species supplying non‐timber forest products) did not differ by the system on average, though the absolute number of useful species recorded was highest for the forest. Of surveyed plant species, 81% had a local name (Sapo or Kru); a smaller proportion of forest species were named compared with either traditional or industrial oil palm systems. Our study emphasises the higher ecological value per hectare of traditional oil palm production compared with industrial production methods, though yields are likely to be lower, leading to implications for industrial management such as growing alternative cover crop species, intercropping with non‐timber forest products or locally valued crops and implementing reduced clearance and pesticide regimes.

Fungal Phytopathogens: Their Role in the Spread and Management of Invasive Alien Plants

Biological invasions pose a major environmental challenge, often facilitating the unregulated dissemination of pathogens and parasites associated with their hosts. These pathogens can severely impact native and cultivated species, with far-reaching ecological and economic consequences. Despite their importance, the mycobiota associated with invasive plant species remains relatively understudied, posing a complex challenge for researchers. The aim of this manuscript is to underscore the most significant threats posed by the uncontrolled transmission of fungal pathogens from invasive alien plants to native environments and agricultural systems, and to identify the factors influencing this phenomenon. We emphasize the role of pathogen spillback and spillover mechanisms in the domestication of invasive alien plants. The influence of environmental, host, and pathogen-related factors on the survival of fungal pathogens were also investigated. Finally, we explore the technical and legal feasibility of using plant pathogens as “green agents” to control invasive alien plants.

Effects of Soil Properties and Altitude on Phylogenetic and Species Diversity of Forest Plant Communities in Southern Subtropical China

The altitudinal distribution pattern of biodiversity is a hot topic in ecological research. This study specifically aims to investigate how altitude influences the spatial distribution of species and phylogenetic and functional diversity within plant communities. By examining three range-gradient communities of Daqing Mountain-Community I (0–300 m), Community II (300–600 m), and Community III (600–900 m), we explore the interrelationship between species diversity, phylogenetic indices, and environmental drivers (altitude, soil physical properties, and chemical properties). We found (1) a correlation between species diversity and phylogenetic structure in Daqing Mountain. Species diversity decreased and then increased with increasing altitude; phylogenetic diversity decreased with increasing altitude, and the phylogenetic structure changed from dispersed to aggregated; (2) Altitude and soil physical and chemical properties are important drivers of species richness, phylogenetic diversity, and phylogenetic structure along the altitude gradient; (3) The structural equations showed that soil physical properties and altitude rise were the key factors contributing to the decrease in biodiversity in Daqing Mountain, with total soil porosity directly influencing soil physical properties and soil water content indirectly. This study not only reveals the pattern of plant diversity along the altitude of Daqing Mountain but also provides a basis for plant conservation planning, habitat maintenance, and management coordination.