Productivity Of Plantations Research Articles

Impact of Loblolly Pine (Pinus taeda L.) Plantation Management on Biomass, Carbon Sequestration Rates and Storage

Loblolly pine plantations have long been cultivated primarily for timber production due to their rapid growth and economic value. However, these forests are now increasingly acknowledged for their important role in mitigating climate change. Their dense canopies and fast growth rates enable them to absorb and store substantial amounts of atmospheric carbon dioxide. By integrating sustainable management practices, these plantations can maximize both timber yield and carbon sequestration, contributing to global efforts to reduce greenhouse gas emissions. Balancing timber production with vital ecosystem services, such as carbon storage, demands carefully tailored management strategies. This study examined how the timing of thinning—specifically early thinning at 17 years and late thinning at 32 years—impacts biomass accumulation, carbon storage capacity, and carbon sequestration rates in loblolly pine plantations located in northern Iran. Two thinning intensities were evaluated: normal thinning (removal of 15% basal area) and heavy thinning (removal of 35% basal area). The results demonstrated that thinning significantly improved biomass, sequestration rates and carbon storage compared to unthinned stands. Early thinning proved more effective than late thinning in enhancing these metrics. Additionally, heavy thinning had a greater impact than normal thinning on increasing biomass, carbon storage, and sequestration rates. In early heavy-thinned stands, carbon storage reached 95.8 Mg C/ha, which was 63.0% higher than the 58.8 Mg C/ha observed in unthinned 32-year-old stands. In comparison, early normal thinning increased carbon storage by 41.3%. In late heavy-thinned stands, carbon storage reached 199.4 Mg C/ha, which was 29.0% higher than in unthinned stands of the same age (154.6 Mg C/ha at 52 years). In contrast, late normal thinning increased carbon storage by 13.3%. Similarly, carbon sequestration rates in unthinned stands were 1.84 Mg C/ha/yr at 32 years and 2.97 Mg C/ha/yr at 52 years. In comparison, 32-year-old stands subjected to normal and heavy thinning had sequestration rates of 2.60 and 2.99 Mg C/ha/yr, respectively, while 54-year-old normally and heavily thinned stands reached 3.37 and 3.83 Mg C/ha/yr, respectively. The highest carbon storage was concentrated in the stems for 52–58% of the total. Greater thinning intensity increased the proportion of carbon stored in stems while decreasing the contribution from foliage. These results indicate that heavy early thinning is the most effective strategy for maximizing both timber production and carbon sequestration in loblolly pine plantations.

Growth, Productivity, and Nutrient Return of a Mixed Plantation of Fast-Growing Eucalyptus Hybrid and Acacia auriculiformis Trees in Thailand

Growth, Productivity, and Nutrient Return of a Mixed Plantation of Fast-Growing Eucalyptus Hybrid and Acacia auriculiformis Trees in Thailand

Impact of spring frosts on the productivity of stone fruit crops and phytosanitary condition of plantations

The study was conducted in 2023-2024 in stone fruit plantations at the laboratory site of the Federal Horticultural Center for Breeding, Agrotechnology, and Nursery, located in Izmailovo, Leninsky District, Moscow Region. The study focused on trees of six cherry varieties (Molodezhnaya, Volochaevka, Assol, Rusinka, Vladimirskaya, Belye Zhuravli), three sweet cherry varieties (Fatezh, Tyutchevka, Iput), three cherry plum varieties (Kubanskaya Kometa, Shatyor, Zlato Skifov), and four plum varieties (Utro, Pamyat Timiryazeva, Tulskaya Chernaya, Yaichnaya Sinyaya). Meteorological conditions are presented according to the data of the automatic meteorological station of the Central Office for Hydrometeorology and Monitoring of the Environment. The study is aimed at determining the impact of recurrent spring frosts on the productivity and phytosanitary condition of stone fruit plantations. The degree of frost damage to stone fruit crops varied during the study years and depended on temperature, duration of frost, and stage of plant development during the period of negative temperatures. The frost dates coincided with the fi rst third of May: May 6, 2023 and May 4, 2024. The minimum temperature during the frost period in 2024 (-1.9 °C was slightly different from that in 2023 (-1.75 °C). The duration of frost accounted for only 4 days in 2023, while in 2024, the unusually cold period with negative temperatures lasted for 10 days. In 2024 the degree of damage to fl wers and ovaries in cherry plums, cherries, and sweet cherries was higher due to the longer exposure to low temperatures and precipitation in the form of rain and snow. A significant decrease in productivity compared to the previous year was noted in the early and mid-ripening cherry varieties Assol, Vladimirskaya, and Molodezhnaya, in the Zlato Skifov cherry plum variety, and in the Tyutchevka cherry variety. The Belye Zhuravli cherry varietiy, Fatezh sweet cherry variety, as well as Tulskaya Chernaya, Yaichnaya Sinyaya, and Utro cherry plum varieties demonstrated high productivity and the greatest resistance to frost. Monitoring of the phytosanitary condition revealed that spring frosts caused a stronger spread and development of several fungal diseases (plum leaf rust and shot-hole disease). In the spring period, a decrease in the number of the main phytophages was revealed in stone fruit orchards, which is associated with the lack of optimal temperature conditions for their development and distribution.

Comparative Study on Growth Characteristics and Early Selection Efficiency of Hybrid Offspring of Populus deltoides 'DD-109' and P. maximowiczii in Liaoning, China.

Poplar is an important tree species for timber supply and ecological protection in northern China. Cultivating and selecting high-quality varieties and germplasm resources suitable for cultivation are key factors in enhancing the quality and productivity of poplar plantations in the arid and semi-arid northern regions with shorter growing seasons. This study conducted a field cultivation experiment on 10 progeny clones from the direct cross (D × M) of imported Populus deltoides 'DD-109' with Populus maximowiczii and 7 progeny clones from the reciprocal cross (M × D) using one-year-old rooted cuttings planted at a 4 m × 8 m spacing. Based on 17 years of annual growth observations, the study systematically compared growth characteristics, age of quantitative maturity, path relationships between traits, and early selection efficiency in the hybrid offspring. The results indicated that the D × M population had superior diameter at breast height (DBH), tree height (H), and volume (V) compared to the M × D population, while the height-to-diameter ratio (HDR) was lower. The growth rate of the 17 clones peaked from 10 to 14 years, with annual volume growth increments (PAIs) higher than mean annual volume increments (MAIs) during the early growth stages; the quantitative maturity age ranged between 12 and 16 years. The D × M population generally reached quantitative maturity earlier than the M × D population, with the fastest clone maturing in 12 years. Four clones (DM-9-17, DM-9-18, DM-9-14, and MD-61) showed values for V, DBH, H, and HDR above the hybrid group average. Path analysis demonstrated that DBH had the most significant direct and indirect effects on V, suggesting it as the best predictor for V. Using DBH as a reference, correlation and early selection efficiency analysis showed a strong relationship between growth characteristics at planting years 4-5 and later-stage performance, indicating this as the optimal period for early selection. These findings contribute to evaluating the production potential of P. deltoides 'DD-109' and P. maximowiczii germplasm in northern China and provide valuable guidance for selecting poplar clones suitable for local cultivation, accelerating breeding processes, and informing management planning for poplar plantations.

Adoption Of Sugarcane Cultivation Technology In Sandy Soil, Purworejo District, Central Java

The efforts to increase agricultural production are expected to year-over-year increase. The aims of this study were 1) to determine the characteristics of farmers in cultivating sugarcane in sandy soil, 2) to determine farmers' adoption of sugarcane plantation cultivation in sandy soil, and 3) to determine the productivity of sugar cane plantations in sandy soil. The research applied descriptive method. The total sample taken was 30 samples who were sugarcane farmers from the sandy soil, Purworejo Regency by purposive sampling. The instrument used was using a Likert scale ranging from strongly agree, agree, undecided, disagree, and strongly disagree. To answer the first objective used descriptive analysis, second, and the third objective used class intervals (low, medium, and high). The results of this study are 1) characteristics of sugarcane farmers on sandy soil in Purworejo Regency are classified as productive, the highest level of education of the farmers is junior high school, the experience of farmers in cultivating sugarcane on sandy soil are > 15 years, the total production of sugarcane are 5- 6 ton, the area of farmer's land are 2-4 Ha, and the productivity level of farmers are 3 - 4 ton/Ha. 2) the adoption rate of sugarcane farmers on the sandy soil of Purworejo Regency are medium, and 3) the level of productivity of sugarcane farmers on the sandy soil of Purworejo Regency is classified as medium productivity. The utilization of coastal land should add compost to increase soil moisture. The seeds that have been certified and have SNI.

Pemanfaatan Abu Sekam Padi dan Abu Boiler Kelapa Sawit Sebagai Pengganti Parsial Semen pada Pencampuran Paving Block

Plantations in Indonesia are vast and numerous. Various types of plantation products are produced every year; examples of plantations are oil palm and rice husk. These two plantations have their waste during the process of becoming finished materials. Examples of these two wastes are oil palm boiler ash and rice husks. These two wastes can be used as a partial substitute for cement because they have several compounds similar to cement. This study used the two wastes as a partial replacement for the cement used to manufacture environmentally friendly paving blocks. This study used substitution variations of 0%, 2%, 4%, 6%, and 8% with a FAS value 0.4. The tests that are used are compressive strength tests and water absorption tests. The optimum compressive strength results in each variation is 0%=25,17 Mpa, 2%=25,88 Mpa, 4%=25,93 Mpa, 6%=26,35 Mpa, and 8%=25,35%. For the optimum results of absorption in each variation is 0% = 3.52%, 2% = 2.41%, 4%= 3.50%, 6% = 4.70%, and 8% = 4.27%. According to SNI 03-0691-1996, it can be categorized as a quality B paving block for parking use. The conclusion is that adding the two wastes can increase the compressive strength until it reaches the optimum point of 6%; meanwhile, for the water absorption capacity, the variation increase can be increased because of the water absorption on the paving block.

Keragaman Tumbuhan Invasif di Perkebunan Sawit PT Perkebunan Nusantara II Deli Serdang, Sumatra Utara

Several species of weeds, categorized as invasive plants, are among the factors inhibiting plantation productivity. The uncontrolled spread and growth of these invasive plants can lead to both economic and ecological losses. This study aimed to analyze the diversity of invasive species in the palm oil plantation area of PT Perkebunan Nusantara II. Plant samples were collected by establishing sample plots in three different blocks using purposive sampling. Additionally, species identification and data analysis were conducted, including the Important Value Index (IVI), diversity index, similarity index, and evenness index. A total of 20 invasive species out of 61 weed species, belonging to 14 families, were identified. The invasive species are primarily herbs, climbing plants, and shrubs. Invasive species are dominated by families Poaceae and Asteraceae. Asystasia gangetica, Mitracarpus hirtus, Peperomia pellucida, and Phyllanthus urinaria were found in all three blocks. However, based on the IVI value, only three invasive species were found to significantly affect the community: P. urinaria, Setaria plicata, and P. pellucida.

Comparison between Solar-Powered and Diesel-Driven Water Pumping Systems for Oil-Palm Irrigation Plantations

This paper presents a comprehensive comparative study between solar-powered and diesel-driven water pumping systems for irrigating oil palm plantations in the dry regions of Malaysia. The study aims to address the need for sustainable and efficient water pumping systems in these areas, considering the costs and environmental impact associated with traditional diesel-driven systems. The research specifically focuses on evaluating the feasibility and effectiveness of solar-powered systems as an alternative to diesel-driven systems in the context of Malaysian oil palm plantations. The study employs the HOMER software to evaluate the feasibility and performance of solar-powered water pumping systems in comparison to conventional diesel-driven systems. The research methodology involves collecting data on oil-palm plantations in dry regions and obtaining relevant meteorological data. Subsequently, solar-powered water pumping systems are modeled and simulated using the HOMER software. A comparative analysis is then conducted, considering factors of electrical and economic performances, to evaluate the feasibility and benefits of solar energy for irrigation in Malaysian oil palm plantations. The findings of the study indicate that the configurations of the system without a battery is the most satisfactory, as it demonstrates decent electrical generation, and economic attractiveness with an internal rate of return (IRR) of 17% and a payback period of 5.72 years. Implementing this configuration of the solar-powered water pumping system offers various advantages, including providing adequate water for boosting plantation production, enhancing sustainability, offering environmental benefits, achieving cost savings, and ensuring economic viability. These findings can assist decision-makers in considering the implementation of solar-powered irrigation systems in Malaysian oil palm plantations.

A review of The Political Economy of Agribusiness: A Critical Development Perspective

Maria Luisa Mendonça's recent book, The Political Economy of Agribusiness: A Critical Development Perspective, challenges the idea that agribusiness is an inevitable evolutionary process. Using a Marxist perspective, the book examines the historical development and consequences of industrial agriculture, particularly in Brazil. The author focusses on the role of international financial capital in expanding sugarcane plantations for ethanol production, contributing to land grabbing, rural displacement and deforestation. Finally, Mendonça offers examples of rural resistance led by peasant and indigenous communities of Brazil and calls for sustainable and equitable agricultural practices, advocating for agrarian reform and food sovereignty.

The Effect of Climatic Conditions on the Seasonality of Pest Insect Populations in Eucalyptus Plantations in the Neotropics.

Eucalyptus (Eucalyptus spp., Mirtaceae) stands out for its remarkable regeneration capacity, making it a valuable tool for recovering degraded areas and for reforestation. Despite its Australian origins, eucalyptus has shown remarkable adaptation to the Brazilian tropical climate, contributing to the wood productivity of the country. However, the extensive monoculture of eucalyptus can increase pest incidence, thus being a significant challenge for the forestry sector, which suffers production losses of up to 30%. We analyzed the occurrence of 11 pest insect species in 450 eucalyptus stands over 9years in the southeastern region of Brazil in our study. We related pest occurrences to specific year periods and climatic variations using circular uniformity analysis and zero-inflated models. We found that the species generally had isolated peaks of occurrence during the year and that the increase in the occurrence of at least five species was related to temperature or precipitation. The results highlight the sensitivity of pests to climatic conditions, showing the importance of management strategies to ensure the sustainability and productivity of eucalyptus plantations. We can develop more effective management strategies by understanding how these variables interact with insect populations, contributing to the sustainability and productivity of eucalyptus plantations with less aggressive environmental practices.

Study of The Role and Function of Agricultural Extension Institutions on Agricultural Development

The role and function of the agricultural extension service for agricultural development which includes services, center of communication, center of institutional development and center of partnership development and the function of extension services as program planning and preparation, provision and dissemination of information, human resource development, administrative structuring and functions evaluation were less optimal. The lack of quantity and quality of agricultural (plantations), extension agents had lack of training along with agricultural (plantations) extension workers, there was a policy of transition from agricultural (plantations) extension workers to food extension workers. Agricultural (plantation) development also seen from economic growth, community welfare, and the increase in plantation production. The decline in production results in several commodities namely cloves, rubber, cocoa and coffee based on data from the statistical center since 2019 to 2022 in Bulukumba regency.

Toward Marker-Assisted Selection in Breeding for Fusarium Wilt Tropical Race-4 Type Resistant Bananas.

Fusarium wilt is a soil borne fungal disease that has devastated banana production in plantations around the world. Most Cavendish-type bananas are susceptible to strains of Fusarium oxysporum f. sp. cubense (Foc) belonging to the Subtropical Race 4 (STR4) and Tropical Race 4 (TR4). The wild banana diploid Musa acuminata ssp. malaccensis (AA, 2n = 22) carries resistance to Foc TR4. A previous study using segregating populations derived from M. acuminata ssp. malaccensis identified a quantitative trait locus (QTL) (12.9 cM) on the distal part of the long arm of chromosome 3, conferring resistance to both Foc TR4 and STR4. An SNP marker, based on the gene Macma4_03_g32560 of the reference genome 'DH-Pahang' v4, detected the segregation of resistance to Foc STR4 and TR4 at this locus. Using this marker, we assessed putative TR4 resistance sources in 123 accessions from the breeding program in Brazil, which houses one of the largest germplasm collections of Musa spp. in the world. The resistance marker allele was detected in a number of accessions, including improved diploids and commercial cultivars. Sequencing further confirmed the identity of the SNP at this locus. Results from the marker screening will assist in developing strategies for pre-breeding Foc TR4-resistant bananas. This study represents the first-ever report of marker-assisted screening in a comprehensive collection of banana accessions in South America. Accessions carrying the resistance marker allele will be validated in the field to confirm Foc TR4 resistance.

Prediction of Oil Palm Plantation Block Productivity Based On Canopy Area And Vegetation Index Using Multispectral Aerial Photographs

The demands of productivity and efficiency of oil palm plantations can be met by implementing Precision Farming (PF), where production analysis is carried out on a narrower area. Currently, yield evaluation or harvest results are carried out based on block area (25-100 Ha). The diverse information in one block is standardized, potentially eliminating detailed information that is useful for management. This study aims to develop an empirical estimation model of oil palm plantation productivity per harvest day through the canopy area approach and oil palm vegetation index with multispectral camera technology. The oil palm productivity estimation method is carried out by comparing the processing results using the Normalized Difference Vegetation Index and Atmospherically Resistant Vegetation Index transformation algorithms. The basis for estimation is per Harvesting Collection Point, namely an area of ± 0.3 ha. The results showed: 1) NDVI, NDRE are strongly and very strongly correlated with FFB production; 2) canopy area has a strong relationship to FFB production; 3) NDVI vegetation index values are strongly correlated with FFB production. The productivity estimation equation from NDRE value: y = 3621.9x – 1153.8, the productivity estimation equation based on canopy area: y = 0.5479x – 717.08, and the productivity estimation equation based on NDVI: y = 11.639x – 9709.2

EVALUATION OF DIFFERENT COMBATING COMBINATIONS AGAINST LEAF-CUTTING ANTS IN Eucalyptus urograndis PLANTINGS

Leaf-cutting ants, genera Atta and Acromyrmex, are one of the main pests in forestry crops. They can affect forest productivity and increase mortality rates in plantations, making their control essential. Thus, this study aimed to evaluate different treatments for combating leaf-cutting ants and their results on the forest inventory of survival. Six treatments were evaluated in an area of approximately 14.000 hectares of Eucalyptus urograndis (Eucalyptus urophylla S. T. Blake × Eucalyptus grandis W. Hill), namely: 1) control, 2) pre-harvest combat, 3) pre-planting combat, 4) two or more pre-planting combats, 5) pre-harvest and pre-planting combat, and 6) pre-harvest combat with two or more pre-planting combats. The analyzed variables were: planted area (ha), planting survival (%), dead attacked seedlings (%), live attacked seedlings (%), and total attacked seedlings (%). Treatment comparisons were conducted using multivariate analysis of variance and discriminant analysis. Treatments that involved combat against ants only before harvesting or combined with pre-planting showed the best performance among the evaluated treatments. The most efficient treatment was the one that combated the ants before harvesting with just one repetition, resulting in reduced silvicultural costs.

KARAKTERISASI KOMPOSIT BERPENGUAT SERAT PELEPAH PISANG SEBAGAI MATERIAL BOX KACAMATA

Considerations in choosing banana stem fiber as an alternative in reducing the use of metal materials or synthetic fibers because they are more environmentally friendly and easy to obtain. Utilizing unused waste from plantation products has a lighter weight because banana stem fiber has quite good mechanical properties. This research aims to determine the mechanical properties of composites reinforced with banana stem fiber with random fiber orientation and using the Eposchon Epoxy Resin A + Hardener EPH 555 matrix as a replacement material for eyeglass cases made of plastic. Banana stem fibers were soaked in 5% NaOH for 2 hours, then composites were made using the hand lay up method with fiber weight fractions of 5%, 10% and 15%. Composite materials produced from the three variations in weight fractions were each subjected to 3 tests, namely tensile tests to ASTM D3039 standards, impact tests to ASTM D256 standards, and bending tests to ASTM D790 standards. The research results showed that the highest tensile strength at the 10% fiber weight fraction was 15.71 MPa, the highest impact value at the 5% weight fraction was 0.611 Joules, and the highest bending strength was obtained at the 5% fiber weight fraction at 69.9 MPa. Judging from the tensile, impact and bending strength of the banana stem fiber composite, it is feasible and meets the requirements to be an alternative material for eyeglass cases made from Polypropylen (PP) plastic.

Seasonal resin production in Pinus pinaster Ait. plantations: Dendrometric and meteorological influences

The relationship between dendrometric and meteorological parameters and resin production in Pinus pinaster plantations was studied using data from 90 trees collected between June and October. Resin production was measured every 15 days over a five-month period to explore how environmental factors influence resin production rates. The correlation between diameter at breast height (DBH) ranging from 20 cm to 49 cm and total and average resin production was examined, with the goal to optimize resin harvesting practices and to understand the ecological significance of resin in these plantations. The bi-monthly resin production was tested using the open wound tapping method over a five-month period beginning in June. Through regression models, significant seasonal variability in resin production was observed. Specifically, higher resin yields were recorded in June (354 g) and lower yields in October (53.5 g). The impact of DBH, tree height, basal area, and volume on resin yield were also assessed. Descriptive statistics, correlation, and regression analyses elucidated the relationships between tree metrics, meteorological factors, and resin production. This study contributes new insights into how tree characteristics influence resin production and how this relationship is modulated by seasonal changes. Such findings can inform sustainable forest management practices and improve resin harvesting methods.

Increasing Agricultural Productivity in the Arabica Coffee Replanting Programme through a Gender Responsive Approach in Toraja District

Tana Toraja, Indonesia, is renowned for its "Toraja coffee," a highly sought-after specialty coffee. To meet the growing global demand, Toraja coffee production needs to increase. However, traditional gender roles often limit participation in coffee farm management. This research explores how integrating the roles of both men and women farmers can improve coffee production and farm management in Tana Toraja. A qualitative method with a phenomenological approach. Primary data sources are male and female farmers, and secondary data is supporting data from relevant agencies in Tana Toraja Regency, Indonesia. Data analysis techniques are used in the form of collection (observation, interviews, questionnaire filling), reduction (summarizing data), data presentation, and data verification (temporary conclusions). In the management of Arabica coffee, male farmers are involved 37.14 percent (less involved), female farmers 40.48 percent (less involved), the involvement of male and female farmers together, and alternately 77.62 percent (fully involved). The coffee rejuvenation program received a response of 45.00 percent (quite responsive) from male farmers; female farmers responded 46.66 (quite responsive), and the reaction of male and female farmers together and alternately was 91.67 percent (fully responsive). This research found that a gender-responsive approach, where both men and women farmers are fully involved in coffee farm management and rejuvenation programs, can significantly increase productivity and sustainability in Tana Toraja's smallholder coffee plantations. By integrating the roles of both genders, the research suggests that coffee farms can benefit from a wider range of skills, knowledge, and perspectives, ultimately leading to a more successful and sustainable coffee industry in Tana Toraja.

Multispectral Images for Drought Stress Evaluation of Arabica Coffee Genotypes Under Different Irrigation Regimes.

The advancement of digital agriculture combined with computational tools and Unmanned Aerial Vehicles (UAVs) has opened the way to large-scale data collection for the calculation of vegetation indices (VIs). These vegetation indexes (VIs) are useful for agricultural monitoring, as they highlight the inherent characteristics of vegetation and optimize the spatial and temporal evaluation of different crops. The experiment tested three coffee genotypes (Catuaí 62, E237 and Iapar 59) under five water regimes: (1) FI 100 (year-round irrigation with 100% replacement of evapotranspiration), (2) FI 50 (year-round irrigation with 50% evapotranspiration replacement), (3) WD 100 (no irrigation from June to September (dry season) and, thereafter, 100% evapotranspiration replacement), (4) WD 50 (no irrigation from June to September (water stress) and, thereafter, 50% evapotranspiration replacement) and (5) rainfed (no irrigation during the year). The irrigated treatments were watered with irrigation and precipitation. Most indices were highest in response to full irrigation (FI 100). The values of the NDVI ranged from 0.87 to 0.58 and the SAVI from 0.65 to 0.38, and the values of these indices were lowest for genotype E237 in the rainfed areas. The indices NDVI, OSAVI, MCARI, NDRE and GDVI were positively correlated very strongly with photosynthesis (A) and strongly with transpiration (E) of the coffee trees. On the other hand, temperature-based indices, such as canopy temperature and the TCARI index correlated negatively with A, E and stomatal conductance (gs). Under full irrigation, the tested genotypes did not differ between the years of evaluation. Overall, the index values of Iapar 59 exceeded those of the other genotypes. The use of VIs to evaluate coffee tree performance under different water managements proved efficient in discriminating the best genotypes and optimal water conditions for each genotype. Given the economic importance of coffee as a crop and its susceptibility to extreme events such as drought, this study provides insights that facilitate the optimization of productivity and resilience of plantations under variable climatic conditions.

Understory vegetation diversity and composition in intensively managed plantations compared to extensively managed forests

The benefits of plantations for wood production are well known, but it is unclear whether they have a clear negative effect on biodiversity, compared to natural forests. It is also unclear how overstory species identity (i.e., exotic, compared to native) would interact with the simple plantation effects on understory vegetation biodiversity. Here, we assessed bryophyte, lichen, and vascular plant diversity and composition in mono-specific and mixed plantations of exotic and native hybrid poplars (Populus spp.) and exotic and native spruces (Picea spp.). We compared these plantations to reference forests with similar overstory types (coniferous, deciduous, mixed) to those of the plantations in the southern boreal forest of Quebec. We also assessed whether the overstory species identity in plantations influenced understory vegetation biodiversity compared to reference forests. Our results show that plantations were not biological deserts, since mixed plantations contained similar bryophyte and vascular plant diversity as reference mixed native forests. The presence of native spruces and exotic poplars in mixed plantations increased bryophyte and vascular plant diversity respectively. This suggests that the influence of plantations on understory species diversity, compared to reference forests, was linked to the overstory species identity. Plantations were associated with ruderal plant species, while reference forests were composed of forest species. Bryophyte composition was similar in plantations and reference forests, while lichen species were only present in plantations. Our findings highlight that plantations, especially mixtures of white spruce and exotic poplar, are a promising option for planting strategies to enhance biodiversity.

Recommendations for Appropriate Design for Handling Landslides on the Slopes of the Balai River (Sei Balai), Batubara Regency

Sei Balai River, precisely in Nibung Hangus/Tanjung Tiram District, Batu Bara Regency, is one of the rivers in the Bah Bolon River Area (WS). Sei Balai River has experienced flooding several times and caused landslides on the riverbanks. One of the most critical locations is in Lima Beras Village, Nibung Hangus/Tanjung Tiram District, Batu Bara Regency, which has damaged the riverbanks which are feared that if not handled early, it may result in the breaking of community access roads in the mobilization and demobilization of agricultural and plantation products in the village. Based on the results of the geotechnical investigation, it was concluded that the Bearing Capacity Value of the Shallow Foundation Permit from the qc Data was obtained at No. Test. S - 1, with a depth of 5 meters, the permitted bearing capacity (Qi) was 3.8 (Ton / m2) with a square foundation width B = 1 m and No. Test. S – 2, with a depth of 5 meters, the permissible bearing capacity (Qi) is 4.53 (Ton/m2) B = 1 m