Plantation Development Research Articles

Application of GIS technologies in surveying the state of forest crops in the green zone of Astana

When carrying out forestry, constant monitoring of plant condition and growth is very important. There is a wide range of Earth remote sensing sources for effective management of woody vegetation in vast areas. The purpose of the study was to identify areas with weekened and dying tree crops in the green observation zone of Astana, Kazakhstan, covering Batys forestry using remote sensing data. The results of studies carried out for research on the growth and development of artificial plantations were obtained. During the experiment, a comparison of remote sensing data was performed using an unmanned aerial vehicle Supercam S350F with multispectral camera Micasense RedEdge and high-resolution measurements obtained with Sentinel-2 and PlanetScope satellites in order to select a method for solving the tasks. Based on the materials of multispectral diagnostics, the state of forest plantations in Batys forestry was revealed, where 35 % of tree crops were classified as healthy, 30 % - as weakened, and 35 % - as dying.

Genetic Divergence Studies among Indigenous Accessions of Cassia auriculata (L.) Roxb., through Screening and Utilization for Chambal Ravine Rehabilitation

Background: Cassia auriculata, L., is an imperative medicinal and traditional neutral colour leaf hair dye yielding in India. This is a multipurpose and indigenous, perennial leguminous shrub and widely used as traditional medicine to cure diabetics by the rural peoples. Tanner’s cassia is also used as neutral henna and its yields natural golden blonde colouring to hair through the dried leaf powder. Young buds are used for yellow colour dye extraction by textile industries. Screening of high tolerance and best performing genotypes is highly essential in this imperative woody legume shrub to rehabilitate the mass erosion prone gullied and ravine lands for productive purpose of the wasteland and degraded lands. Methods: Thirty different accessions of Cassia auriculata were assembled and numbered from CA-1 to CA-30 from arid and semi-arid regions of Rajasthan (India). The experimental trial was conducted at ICAR-IISWC, Research Centre, Kota-Rajasthan, India during 2019-2022. After evaluation, CA-4 genotype was selected as an elite genotype. The elite genotype was used for high density plantation development with resource conservation for green cover development in non-arable ravine lands. Result: Genetic variation studies of Cassia auriculata indicated that considerable and significant variability, abundant morphometric variations in assembled genotype progenies. Further, genetic divergence analysis was also revealed that nine clusters segregated from 30 genotypes. Thirty genotypes were grouped into nine clusters according overall performance with geographical identity. Finally, C. auriculata (CA-4) genotype was identified and selected as an elite genotype based on its overall superiority in terms of plant growth, higher green biomass, leaf litter biomass, more number branching behaviour and plant coppicing ability which are directly relevant and imperative in soil erosion control, resource conservation and potential rehabilitation effect in resource poor dry regions of non-arable lands.

The Effects of Off-Farm Employment on Non-Timber Forest Product Plantations

Non-timber forest product plantations (NTFP plantations), also known as “economic forests” in China, refer to forest plantations cultivated for the production of non-timber products such as fruits, nuts, oils, seasonings, and medicinal materials. With a rapid increase in the total area in the past two decades, NTFP plantations have become an important type of forestland use in China. The shift of agricultural labor to the non-agricultural sector caused by rising salaries in China will inevitably have a great impact on land use, forestry, and agricultural production. To understand the effects of off-farm employment on the development of NTFP plantations in China, a total of 709 valid household questionnaires from Sichuan and Shaanxi provinces were collected. Heckman’s two-stage model was employed in the empirical analysis. The results of the study show that off-farm employment has a significant positive effect on both the probability that a household has planted NTFP plantations and the plantation area. Households engaged in off-farm employment would prefer to plant NTFP plantations. Moreover, the higher the degree of participation in off-farm employment, the more likely households are to choose to plant NTFP plantations. The area of NTFP plantations would increase with the increase in off-farm employment degrees. Besides, the age and education level of the household head show a positive effect on the NTFP plantation planting. The implication of the results is that with a continuing increase in the proportion of off-farm employment, NTFP plantation cultivation could also continue to expand. Funds are still an important constraint for households to choose to plant NTFP plantations. Therefore, if policymakers want to promote the development of NTFP plantations on collectively owned forestland, they should first resolve households’ financial constraints.

Unmanned aerial vehicles (UAV) utilization for mapping the health of oil palm plants (Elaeis guineensis Jacq.)

The increasing development and expansion of oil palm plantations in Indonesia cause monitoring management to be increasingly difficult to manage a plantation and currently requires technological innovation that is faster and more accurate in providing information, one of which is using an unmanned aerial vehicle (UAV), often called a drone, a flying machine. Which is controlled remotely using a remote control from outside the vehicle, this is used for monitoring and calculating the number of healthy and diseased plants in a large plantation area that can be covered. The purpose of this research is to map the health of oil palm plants using drone technology. The research method is using drones and oil palm application (OPA) software to calculate the number of oil palm stands followed by plant verification with a plant census using a global positioning system (GPS) to determine the distribution of healthy and diseased oil palm plants. The result of the research is a map that displays information on plant health and the number of plants characterized by colour.

Persistent soil organic carbon deficits from converting primary forests to plantations and secondary forests in subtropical China

Soil organic carbon (SOC) plays a critical role in supporting key ecosystem functions and services for humanity. Despite the widespread conversion of primary forests to plantations and secondary forests, it remains uncertain how it affects the content and distribution of SOC. We evaluated SOC content, its components in two fractions, particulate organic carbon (a mean residence time shorter than decades) and mineral-associated organic carbon (a mean residence time of multiple decades to centuries), and the fine root characteristics (biomass, necromass, and C: N of dead fine roots) across Chinese fir plantations and secondary forests during stand development (5–41 years old) in subtropical China, employing primary forests as a reference. We found that SOC content differed significantly between forest types and soil depths, but not with stand age within plantations or secondary forests. In the topsoil (0–10 cm), the SOC content of primary and secondary forests was 47 % and 25 % higher than that of Chinese fir plantations, respectively. The SOC content in the subsoil (40–60 cm) was approximately 6 ± 1.7 mg C g−1 and did not change significantly with forest types or stand ages. The higher SOC contents in primary forests and secondary forests in topsoil resulted primarily from particulate organic carbon accumulation caused by higher fine root biomass and dead root C: N. The fraction of mineral-associated organic carbon to SOC increased with soil depth and was higher in Chinese fir plantations than in secondary forests, suggesting that more SOC is composed of mineral-associated organic carbon that was associated with a higher amount of fine root necromass. Contrary to our expectations, we found SOC content or its fractions did not increase with 40 years of plantation and secondary forest development. Our results reveal persistent SOC deficits from converting primary forests to plantations and secondary forests and highlight the urgent need to conserve the remaining primary forests and protect secondary forests and plantations from disturbances, allowing them to evolve towards older-aged primary forests.

Rubber Tree Recognition Based on UAV RGB Multi-Angle Imagery and Deep Learning

The rubber tree (Hevea brasiliensis) is an important tree species for the production of natural latex, which is an essential raw material for varieties of industrial and non-industrial products. Rapid and accurate identification of the number of rubber trees not only plays an important role in predicting biomass and yield but also is beneficial to estimating carbon sinks and promoting the sustainable development of rubber plantations. However, the existing recognition methods based on canopy characteristic segmentation are not suitable for detecting individual rubber trees due to their high canopy coverage and similar crown structure. Fortunately, rubber trees have a defoliation period of about 40 days, which makes their trunks clearly visible in high-resolution RGB images. Therefore, this study employed an unmanned aerial vehicle (UAV) equipped with an RGB camera to acquire high-resolution images of rubber plantations from three observation angles (−90°, −60°, 45°) and two flight directions (SN: perpendicular to the rubber planting row, and WE: parallel to rubber planting rows) during the deciduous period. Four convolutional neural networks (multi-scale attention network, MAnet; Unet++; Unet; pyramid scene parsing network, PSPnet) were utilized to explore observation angles and directions beneficial for rubber tree trunk identification and counting. The results indicate that Unet++ achieved the best recognition accuracy (precision = 0.979, recall = 0.919, F-measure = 94.7%) with an observation angle of −60° and flight mode of SN among the four deep learning algorithms. This research provides a new idea for tree trunk identification by multi-angle observation of forests in specific phenological periods.

The Evaluation of Plantation Development Policy in the City of Tidore Island

The purpose of this study is to evaluate the policy of providing assistance in the form of seeds for agriculture in Oba District, the city of Tidore Island. The research method used is descriptive qualitative in which an interview with 35 farmers from 12 villages and 1 sub-district is conducted. The results indicate that the policy on seeds provision to farmers in the city of of Tidore Island has been on target, yet it has not been successful due to inadequate support given concerning the ongoing guidance and supervision, therefore most of the seeds received are not planted. Another research finding is that the role of Gapoktan (Gabungan Kelompok Tani Farmers Group Association) in every village of Oba District is not optimum since access to information regarding facilities and infrastructure is limited.

Carbon dioxide emissions through land use change, fire, and oxidative peat decomposition in Borneo

Borneo has accumulated an abundance of woody carbon in its forests and peat. However, agricultural land conversion accompanied by plantation development, dead wood burning, and peat drying from drainage are major challenges to climate change mitigation. This study aimed to develop a method of estimating carbon dioxide (CO2) emissions from land use change, forest and peat fires, and oxidative peat decomposition, and CO2 uptake from biomass growth across Borneo using remote sensing data from 2001 to 2016. Although CO2 uptake by biomass growth in vast forests has shown a significant increasing trend, an annual net release of 461.10 ± 436.51 (average ± 1 standard deviation) Tg CO2 year−1 was observed. The estimated emissions were predominantly characterized by land use changes from 2001 to 2003, with the highest emissions in 2001. Land use change was evaluated from annual land use maps with an accuracy of 92.0 ± 1.0% (average ± 1 standard deviation). Forest and peat fires contributed higher emissions in 2002, 2006, 2009, 2014, and 2015 compared to other years and were strongly correlated with the Southern Oscillation Indexes. These results suggest that more CO2 may have been released into the atmosphere than previously thought.

Social-life cycle assessment of oil palm plantation smallholders in Bengkulu province, Indonesia

Smallholders are often seen as a weak point in the development of oil palm plantation production. The quality and yield of their production are considered low according to world market standards; the continuity of their production is irregular; and finally, improving the welfare of farmers is difficult to achieve. However, smallholder plantations have an important and strategic role in achieving sustainable development. This study aims to assess the social life cycle assessment of smallholder oil palm plantations in Bengkulu Province by involving stakeholders consisting of workers, local communities, farm owners, and value chain actors. A total of 600 respondents were selected using quota sampling and interviewed using a structured questionnaire. Data analysis was conducted using social-life cycle assessment, involving various social issues and relevant social indicators for each stakeholder. The findings in our research show that smallholder oil palm plantations still do not meet the minimum wage for workers, and the equipment used by workers is still very minimal in terms of security and safety guarantees. The price of palm oil continues to fluctuate, and plantation policies are constantly changing, making it difficult for oil palm owners to meet the standards and various rules that are set for managing oil palm plantations. In addition, oil palm plantations are no longer a guarantee for the fulfillment of food security conditions for household owners, workers, communities, and actors involved in the oil palm institutional chain. Our finding is that, surprisingly, there is a low level of commitment by smallholders and the government to sustainability in oil palm plantations. The Indonesian Sustainable Palm Oil and Roundtable on Sustainable Palm Oil as standards for sustainable oil palm plantations, as well as global standards for oil palm plantations to demonstrate environmentally friendly production processes, have not been able to compel smallholders to implement sustainable development in oil palm. Various policies formulated by the Indonesian government are perceived to have not addressed the core issues faced by small-scale farmers. Policies supporting small-scale farmers, particularly those related to increasing productivity, fostering and monitoring the environmental management of palm oil plantation activities, and ensuring ownership of plantation, are necessary for the achievement of sustainable smallholder palm oil plantation development.

Sultan, Plantations, and Islam: Dynamics of Social-Political Life in East Sumatra (1900-1942)

This research explores the dynamics of social and political life in East Sumatra from 1900 to 1942, focusing on the role of the Sultan, plantations, and Islam. The research employed historical research methods in four steps: heuristic, criticism, interpretation, and historiography. Data were collected from relevant archives, books, articles, and reports on the research topic. The research is grounded in three hypotheses: 1) the Sultan and local elites played a significant role in the development of plantations in East Sumatra; 2) Islam served as a crucial factor in shaping political and social identities in East Sumatra; and 3) conflicts of interest between local elites and the colonial government influenced the dynamics of social and political life in East Sumatra during the studied period.

Land use/land cover change-induced greenhouse gas emissions in the global biosphere reserve of tropical Afromontane forest

Land use/land cover (LULC) change is a prominent problem and source of greenhouse gas (GHG) emissions in tropical forests. However, little to no evidence is available on the contribution of biosphere reserves to reversing LULC change trajectories and reducing GHG emissions, particularly in tropical Afromontane forests. The objective of this study was to quantify the LULC change-induced GHG emissions from 1999 to 2020 in tropical Afromontane forests that were designated the Sheka Forest Biosphere Reserve (SFBR) by the MAB program of UNESCO in 2012. The IPCC Tier 1 approach was used to estimate GHG emissions. The results showed that the aggregated GHG emissions were 0.4 tonnes of CO2e ha−1 yr−1 in 1999, while they climbed to 1.46 tonnes of CO2e ha−1 yr−1 in 2010 and 5.2 tonnes of CO2e ha−1 yr−1 in 2020. Deforestation and forest degradation, the expansion of cropland, the development of tea plantations, settlement expansion, and the forest degradation of wetlands contributed to increased emissions by 40.4%, 32.2%, 17.6%, 8.3%, and 1.5% in 2010 and by 60%, 20%, 5.2%, 14.4%, and 0.33% in 2020, respectively. As a result, compared to 9.03 tonnes of CO2e ha−1 yr−1 in 1999, the overall GHG mitigation potential of the SFBR decreased by 12.6% in 2010 and 40.2% in 2020. The findings suggest that the SFBR's capacity to reduce GHG emissions was neither enhanced nor maintained by its designation as a forest biosphere reserve. Therefore, regularly monitoring the effectiveness of interventions and reconciling conflicting land use priorities would be essential for maintaining Afromontane forests and reducing GHG emissions. Promoting tree planting, afforestation, reforestation, and restoring degraded forest landscapes would play a vital role to minimize GHG emissions and enhance the mitigation potential of the ecosystem.

PROBLEM ANALYSIS OF THE DEVELOPMENT OF PALM OIL PLANTATIONS PT. AGRO SYNERGY NUSANTARA KEBUN UJUNG LAMIE, NAGAN RAYA REGENCY

Oil palm is a plantation crop that produces vegetable oil while increasing the economy of people in developing countries, including in Indonesia, including PT. ASN is located in Nagan Raya district, but various problems are faced in developing the oil palm plantation. This research was conducted with the aim of looking at the various problems faced by PT. ASN Nagan Raya district in the development of oil palm plantations, using 11 staff respondents and employees of plantation companies, the results of this study indicate that the problem of developing PT. ASN at Ujung Lamie Nagan Raya Gardens are low productivity, low human resources, unstable finances, lack of fertilization, poor road infrastructure, lack of discipline, Inadequate facilities, many vacant areas, attacks by pigs and porcupines during planting, lack of harvesting bridges, high fertilizer prices and educational factors. Solving these various problems can develop plantations in accordance with the company's business objectives.

Environmental Adaptability and Energy Investment Strategy of Different Cunninghamia lanceolata Clones Based on Leaf Calorific Value and Construction Cost Characteristics.

The calorific value and construction cost of leaves reflect the utilization strategy of plants for environmental resources. Their genetic characteristics and leaf functional traits as well as climate change affect the calorific values. This study explores the differences in energy investment strategies and the response characteristics of energy utilization in leaves to climate change among nine clones of Chinese fir (Cunninghamia lanceolata). Considering the objectives, the differences in the energy utilization strategies were analyzed by determining the leaf nutrients, specific leaf area, and leaf calorific value and by calculating the construction cost. The results showed a significant difference in the ash-free calorific value and construction cost of leaves among different Chinese fir clones (p < 0.05). There were also significant differences in leaf carbon (C) content, leaf nitrogen (N) content, specific leaf area, and ash content. The correlation analysis showed that leaves' ash-free calorific value and construction cost were positively correlated with the C content. Principal component analysis (PCA) showed that P2 is inclined to the "fast investment return" energy investment strategy, while L27 is inclined to the "slow investment return" energy investment strategy. Redundancy analysis (RDA) indicates that the monthly average temperature strongly correlates positively with leaf construction cost, N content, and specific leaf area. The monthly average precipitation positively impacts the ash-free calorific value and construction cost of leaves. In conclusion, there are obvious differences in energy investment strategies among different Chinese fir clones. When temperature and precipitation change, Chinese fir leaves can adjust their energy investment to adapt to environmental changes. In the future, attention should be paid to the impact of climate change-related aspects on the growth and development of Chinese fir plantations.

Socioeconomic Development of the Local Community and Causes of Land Use Change in Belaga, Sarawak, Malaysia

The state of Sarawak in Malaysia has witnessed a surge in demand for its valuable land resources, primarily driven by major commodity investors establishing plantations. These land concessions have further exacerbated land scarcity and the depletion of crucial forest areas, which are essential for the livelihoods of indigenous communities. The indigenous community in Sarawak, heavily dependent on forests, faces significant challenges due to land use changes. This study aims to identify the drivers of land use change and assess the socioeconomic impact on the local community in Murum, Belaga, Sarawak. The research was conducted in December 2020, utilizing a combination of quantitative and qualitative approaches. Questionnaires, in-depth interviews, and site observations were employed to collect data, involving 511 household heads and ten key informants. Statistical analysis using SPSS software was performed on the collected data. The findings highlight that the primary cause of land use change in the study area was the hydroelectric dam project, followed by the establishment of oil palm plantations, logging activities, forest plantation development, government policies, and agricultural activities. Regarding infrastructure satisfaction levels, respondents ranked sport/recreational facilities as the most important, followed by electricity supply, house/accommodation facilities, education facilities, clean water sources, communication accessibility, health facilities, and road accessibility. Overall, the data indicates an improvement in the economic and social conditions of families due to land use changes in the area. However, the study concludes that there is still a need for further improvements in essential services, including providing multiple clean water sources to each household, enhancing access to healthcare services, and improving road conditions. Improved road access will foster increased business and social activity, facilitating job opportunities and contributing to poverty alleviation within the local community.

Effects of thinning on functional and phylogenetic diversity of regenerated woody plants in plantations over time

AbstractAimsConversion of natural mixed forests into monoculture plantations results in a loss of biodiversity, and consequently leads to serious ecological problems (e.g. soil acidification and soil fertility declines) by controlling the quantity and quality of litter entering the soil. Plant diversity in the understorey is the most important component of aboveground biodiversity in plantations and plays a critical role in the sustainable development of plantations. Thinning has been proven effective in promoting the regeneration of understorey plants, and most studies have targeted the effects of thinning on a single biodiversity index (e.g. species richness) of the understorey in plantations. The effects of thinning on functional and phylogenetic diversity are less addressed, however, which could limit the full understanding of biodiversity maintenance and potential processes of community assembly integrally in plantations after thinning.LocationNortheast China.MethodsWe chose young and middle‐aged larch (Larix kaempferi) plantations based on the time after thinning (short term, 1–3 years; medium term, 4–9 years; and long term, 10 years or longer), quantified the functional and phylogenetic diversity and the structure of regenerated woody plants in the understorey, and related the functional and phylogenetic diversity to environmental factors (canopy openness and soil nutrients).ResultsFunctional richness and evenness decreased over time after thinning in two types of plantations, and in the medium term the functional divergence of young plantations was significantly lower. At short term after thinning, the phylogenetic diversity was higher in two types of plantations. Functional richness was significantly related to canopy openness in young plantations, while functional divergence was closely related to soil phosphorus content in middle‐aged plantations. Functional and phylogenetic structure of the regenerated woody community changed from dispersion to clustering and had a significant relationship with environmental conditions (e.g. light availability in both young and middle‐aged plantations), highlighting that environmental filtering gradually became the main driving force of community assembly in the regenerated community of the understorey.ConclusionThe functional and phylogenetic diversity of regenerated woody plants changed over time after thinning under the influence of light availability, and environmental filtering played a crucial role in the assembly of the understorey community. Our study expands the research of biodiversity maintenance by considering the effects of thinning over time, and provides new insights into the management and sustainable development of plantations.

Assessment of farmers’ preferences for growing particular crops and the correlation with land suitability

The success of agricultural operations is highly dependent on the site selected, which affects sustainability, and it is important to solve problems associated with activities and efficient land use. However, many researchers have selected sites based solely on climate and soil characteristics and have ignored farmer preferences, which has resulted in the failure to meet sustainable agriculture goals, and a proper strategy is therefore required to anticipate related problems. This study was conducted to: (1) analyze plantation development priorities based on the hierarchy of farmers’ preferences, (2) identify the relationship between successful plantations, climate, and soil fertility. The attributes employed to assess farmers’ preferences included price, production, and price stability over the past five years, while annual rainfall, annual temperature, and soil fertility were used to assess land suitability. Farmers’ preferences were analyzed using the discrete choice experiment (DCE) method, and land suitability was analyzed using the fuzzy method. The farmer preference analysis showed that coffee was the priority crop of farmers in most of the research areas, and cocoa was the lowest cultivation priority. Coffee had a higher land suitability index than other plants, ranging from 0.62 to 0.92, and it was dominant within the optimal suitability class. Clove, pepper, and cocoa plants belonged to the moderate land suitability class with indexes of 0.6–0.91, 0.56–0.88, and 0.4–0.86 for pepper, clove, and cocoa, respectively. A regression analysis was conducted to determine the relationship between the priority of cultivated plants based on farmers’ preference and land suitability, and a positive relationship (moderate strength) was determined. These research results show that when selecting priority crops, 21% of farmers’ decisions are influenced by land suitability.

Mapping smallholder cashew plantations to inform sustainable tree crop expansion in Benin

Cashews are grown by over 3 million smallholder farmers in >40 countries worldwide as a principal source of income. Expanding the area of cashew plantations and increasing productivity are critical to improving the livelihood of many smallholder communities. As the third largest cashew producer in Africa, Benin has nearly 200,000 smallholder cashew growers contributing 15% of the country's national export earnings. Expansion of the cashew industry is thus an essential economic driver and a governmental priority in Benin. However, a lack of information on where and how cashew trees grow across the country hinders decision-making that could support increased cashew production and poverty alleviation. By leveraging 2.4-m Planet Basemaps and 0.5-m aerial imagery, two newly developed deep learning algorithms, and large-scale ground truth datasets, we successfully produced the first-of-its-kind national map of cashew in Benin and characterized the expansion of cashew plantations between 2015 and 2021. In particular, we developed a SpatioTemporal Classification with Attention (STCA) model to map the distribution of cashew plantations with 2.4-m multi-temporal Planet Basemaps from 2019 to 2021, which can fully capture texture information from discriminative time steps during a growing season. The U-Net model was employed to map the distribution of cashew plantation with 0.5-m mono-temporal aerial imagery in 2015, which can achieve accurate and fast predictions even with limited training data. We further developed a Clustering Augmented Self-supervised Temporal Classification (CASTC) model to distinguish high-density versus low-density cashew plantations by automatic feature extraction and optimized clustering. Results show that the STCA model has an overall accuracy over 85% based on 1400 ground truth point samples from each year. The CASTC model achieved an overall accuracy of 76% based on 348 ground truth samples of planting density. We found that the cashew area in Benin has almost doubled to 519 ± 20 kha from 2015 to 2021 with 60% of new plantation development coming from cropland or fallow land, while encroachment of cashew plantations into protected areas has increased by 55%. Only about half of cashew plantations were high-density in 2021, suggesting high potential for intensification. Our study illustrates the power of combining high-resolution remote sensing imagery and state-of-the-art deep learning algorithms to better understand tree crops in the heterogeneous smallholder landscape, which can help efficiently allocate limited training and nursery resources for sustainable agricultural development.

Vegetation Analysis on the Upper Mahakam River Border

Vegetation analysis on the upper Mahakam river border. The Mahakam River Basin (DAS) is very wide, reaching 7.724.300 Ha. The condition of the vegetation in the Mahakam watershed continues to change due to the development of plantations, mining, and settlements. On the other hand, efforts to maintain biological resources from the diversity of vegetation are needed to protect against extinction. Remote sensing data can be used to differentiate between primary and secondary vegetation economically. However, it has limitations for detecting vegetation composition and the number of individuals per unit area. Therefore, field surveys in the context of conducting vegetation analysis are still needed to complement remote sensing data. This study aims to analyze the vegetation in each growth phase, namely the seedling, sapling, pole, and tree phases on the Mahakam riverbank. The method used is to make observation plots of 13 plots for each growth phase. Plots of 2 x 2 m2 for seedling observation, 5 x 5 m2 for sapling level, 10 x 10 m2 for pole level, and 20 x 20 m2 for tree level observation. Based on data analysis, the seedling stage consisted of 30 species, the average number of stems was 25576.9 per ha, the species diversity index was 1.371, and the highest important value index was 21.8% of Coffea robusta. There were 17 species of saplings, an average number of 4,092.3 stems per hectare, a diversity index of 1,118, and the highest important value index of 39.5% from Theobroma cacao. The pole level contained 16 species, the average number of stems was 1023.1 per hectare, the diversity index was 1.138, and the highest interest index was 23.7% for Paraserianthes falcataria. The tree level consists of 30 species. The average number of stems is 255.8 per hectare, the diversity index is 1.282, and the highest important value index is 54.9% of Durio zibethinus. From the results of the study, it can be concluded that most of the vegetation in the Mahakam riverbank area is former fields or agricultural activities.

Integration of transcriptomic and metabolomic analysis unveils the response mechanism of sugar metabolism in Cyclocarya paliurus seedlings subjected to PEG-induced drought stress

Cyclocarya paliurus (Batal.) Iljinskaja is a multiple function tree species used for functional food and valued timber production. Carbohydrates, especially water-soluble carbohydrates, play an important role in osmotic protection, signal transduction and carbon storage. Under the circumstance of global climate change the abiotic stress would restrict the development of C. paliurus plantation, whereas there is few knowledge on the regulatory mechanisms of sugar metabolism under drought stress in C. paliurus. To investigate the drought response of C. paliurus at molecular level, we conducted an integrated analysis of transcriptomic and metabolomic of C. paliurus at three PEG-induced drought stress levels (0%: control; 15%: moderate drought; 25%: severe drought) in short term. Both moderate and severe drought treatments activated the chemical defense with lowering relative water content, and enhancing the contents of soluble protein, proline and malondialdehyde in the leaves. Meanwhile, alterations in the expression of differentially expressed genes and carbohydrate metabolism profiles were observed among the treatments. Weighted gene co-expression network analysis (WGCNA) showed 3 key modules, 8 structural genes (such as genes encoding beta-fructofuranosidase (INV), sucrose synthase (SUS), raffinose synthase (RS)) and 14 regulatory transcription factors were closely linked to sugar metabolism. Our results provided the foundation to understand the response mechanism of sugar metabolism in C. paliurus under drought stress, and would drive progress in breeding of drought-tolerant varieties and plantation development of the species.

Environmental impacts of air pollution and its abatement by plant species: A comprehensive review.

Air pollution is one of the major global environmental issues urgently needed attention for its control through sustainable approaches. The release of air pollutants from various anthropogenic and natural processes imposes serious threats to the environment and human health. The green belt development using air pollution-tolerant plant species has become popular approach for air pollution remediation. Plants' biochemical and physiological attributes, especially relative water content, pH, ascorbic acid, and total chlorophyll content, are taken into account for assessing air pollution tolerance index (APTI). In contrast, anticipated performance index (API) is assessed based on socio-economic characteristics including "canopy structure, type, habit, laminar structure, economic value and APTI score" of plant species. Based on previous work, plants with high dust-capturing capacity are identified in Ficus benghalensis L. (0.95 to 7.58mg/cm2), and highest overall PM accumulation capacity was observed in Ulmus pumila L. (PM10 = 72µg/cm2 and PM2.5 = 70µg/cm2) in the study from different regions. According to APTI, the plant species such as M. indica (11 to 29), Alstonia scholaris (L.) R. Br. (6 to 24), and F. benghalensis (17 to 26) have been widely reported as high air pollution-tolerant species and good to best performer in terms of API at different study sites. Statistically, previous studies show that ascorbic acid (R2 = 0.90) has good correlation with APTI among all the parameters. The plant species with high pollution tolerance capacity can be recommended for future plantation and green belt development.