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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Carbon stock estimation of agroforestry system in Tawau, Sabah
Get PDFStudies on total aboveground carbon (TAC) and belowground carbon (TBC) stock has been conducted in Balung Plantation, Tawau, Sabah. The main objective of the study was to determine the above and below ground carbon stock in agroforestry system. The combination of agroforestry systems with different ages were investigated, which is oil palm (25 years) and agarwood (7 years), oil palm (20 years) and agarwood (7 years), and oil palm (17 years) and agarwood (5 years). Monoculture of oil palm (16 years) and Tawau Hill Park forest reserve was set as control. A random systematic sampling method was used in conducting field inventory and soil sampling. The size of the sampled area in agroforestry and monoculture is 3 × 50m × 50m, while for forest reserve, the sampled area is 3 x 30m x 30m. Allometric equations were used to calculate the stand biomass. Sampling for organic and shrub layers were collected in a square frame (1m × 1m). Soil samples and bulk density was collected from three different layers which are 0 – 5 cm, 5 – 10 cm and 10 – 30 cm in randomly located sites within the plots. Soil samples, organic and shrub layer were analyzed using CHN628 series for carbon content. Result shows that the amount of total carbon stock in agroforestry was 79.12 tan C ha-1, 85.39 tan C ha-1 and 78.27 tan C ha-1, respectively. Monoculture of oil palm (16 years) has 76.44 tan C ha-1 while Tawau Hill Park forest reserve has total carbon stock at 287.38 tan C ha-1. Forest reserve stand has the highest total carbon stock compared to agroforestry and monoculture systems. But, in terms of soil carbon, forest reserve has the lowest TBC compared to agroforestry and monoculture systems. ANOVA was conducted to explore the impact of planting systems on total carbon stock. There was a statistically significant difference at the p < .05 level for soil carbon, living tree and organic layer between agroforestry, monoculture and forest reserve. Good crop and fertilizer management in agroforestry and monoculture systems helps in increasing soil organic carbon (SOC)
A review of fertilizer use in Malaysian forest plantations: Future plans for sustainable forestry
No full textLimited reviews to date, and subsequently we have discussed the factors that affect forest plantations’ ability to
produce sustainably, such as fertilizer usage and silviculture. The creation of an appropriate framework for
managing tree fertilization for planted forests in the future will be aided by previous studies and present
requirements. Here, we will discuss the various approaches to ensure effective and efficient fertilizer
management in the plantations, along with the challenges and future trends in fertilizer management systems for
sustainable forest plantations in Sabah, Malaysia. Applying bio-fertilizers is therefore a good way to improve and
preserve the soil’s nutrient economy, which lowers the need for chemical fertilizers for efficient and sustainable
farming. This study presents the most recent and practical technologies for applying different fertilizers to
seedlings in forests and nurseries
Carbon pool in different land use in Germany
Get PDFThe impact of land use on carbon pools were investigated in three different land use type (forestland, arable land and grassland) in Katinger Watt area in Northern Germany. The area was once a sea floor (tidal flat) that was dyked in 1973. Relevant condition for carbon turnover in the studied area were similar, thus the different in carbon pools during soil genesis were attributed to different land use systems
Aboveground carbon stock potential of teak (tectona grandis) under different land use system in Balung plantation, Tawau Sabah
Get PDFAssessment of aboveground carbon stock in different teak plantation systems was conducted in Balung River Plantation, Tawau, Sabah. The objective of this study is to determine the potential of teak as the main tree components to increase the above ground carbon stock in different land use system. The above ground carbon stock of agroforestry and mixed plantation system of teak (Tectona grandis) were compared with natural forest and monoculture plantation of the species. The agroforestry combinations investigated are agroforestry system 1, teak (18 years) with snake fruit (8 years) and agarwood (8 years); agroforestry system 2, teak (17 years) with coffee (14 years); and also mixed timber plantation system, teak (18 years) with agarwood (8 years); while 20 years teak monoculture plantation and natural forest reserve was set up as a control. A random systematic sampling method was used in conducting field inventory. The methodologies used include the measurement of height and diameter breast height (DBH) of trees within a 50 m x 50 m plot dimension (for plantation) and 30 m x 30 m (forest). Allometric equations were used to derive the field measured attributes into stand biomass while carbon stock was estimated as 50 percent from the total biomass. The result shows the accumulation of carbon stock goes in the following order: forest reserve (213.84 t C/ha) > mixed timber plantation (69.94 t C ha-1 ) > agroforestry system 2 (37.75 t C/ha) > agroforestry system 1 (37.34 t C/ha) > teak monoculture (34.53 t C/ha) witnessing the teak trees to increase the total aboveground carbon stock in agroforestry and mixed timber plantation system by more than 60 percent. This study suggested that teak has great potential in transforming a low biomass land use into a carbon-rich tree based systems
Carbon stocks and sequestration potential in agroforestry system
Get PDFStudies on carbon stock in agroforestry systems has been conducted in Balung River Plantation, Tawau, Sabah. The objective of the study are to determine carbon content of above ground vegetation including crops, shrubs and trees in agroforestry system, to determine carbon content of soil in agroforestry system, to estimate aboveground carbon stock using UDAR data and to estimate carbon sequestration potential in agroforestry system. Three combination of oil palm (Elaeis guineensis) and agarwood (Aquilaria malaccensis) in agroforestry system with different age were investigated. The combinations are oil palm (27 years) and agarwood (7 years), palm oil (20 years) and agarwood (7 years) and oil palm (17 years) and agarwood (5 years). Oil palm plantation (16 years) and forest reserve was investigated as a control. Agroforestry system of teak (Tectona grandis), agarwood (Aquilaria malaccensis) and snake fruit (Salacca zalacca) were also assessed for carbon storage ability in comparison with LiDAR data. A random systematic sampling method was used for conducting the forest inventory. Three square plots of 0.25 ha were established in each of the agroforestry system site. Soil were taken at the depth 0-5 cm, 5-10 cm and 10-30 cm. Shrub layer and organic layer were taken at five randomly selected positions in each plot. Field measured attributes such as height and DBH were measured and then converted into above ground biomass by using site specific allometric equation. carbon stocks were considered to be 50 percent of the total biomass. The results shows that forest have the highest carbon stock (287.38 tan C ha·1) in comparison with three oil palm agroforestry systems (79.12 tan C ha·1, 85.39 tan C ha·1 and 78.27 tan c ha·1) and monoculture oil palm plantation (76.44 tan C ha·1). In teak, agarwood and snake fruit agroforestry combination, the total carbon stock is 44.04 tan C ha·1 in which 70 percent of it were contributed by the teak stand. Significance correlation were also found for field measured height and LiDAR maximum height for teak and agarwood (R2 = 0.807, teak; R2 = 0.923, agarwood) in individual tree analysis. For plot level approach, canopy coverage percentage flor UDAR data shows strong correlation with above ground carbon of snake fruit (R2 = o. 756). This study found that agroforestry systems have great potential in carbon storage and carbon sequestration and the use of remote sensing technology offers were capable in improving above ground carbon stock estimates
Economic analysis of intercropping Orthosiphon Stamineus with Durio Zibethinus and Hevea Brasiliensis with different organic fertilizer regimes
Get PDFEconomic analysis on Orthoslphon stamineus Benth. under rubber and durian farm was conducted at Kg. Kogopon, Papar, Sabah. The main objective of this study was to study
the economic viability of planting Orthosiphon stamineus (Misai Kucing) in Rubber and Durian farm involving fertilizer application of various types. A Randomized Complete
Block Design (RCBD) was used. O. stamineus was planted with spacing 1.5 m between rows and 0.45 m within rows of plants. The site was divided into three (3) blocks or replicates. Each block contained four (4) treatments and 20 plants of O. stamineus for each treatment. Three (3) organic fertilizer treatments were applied to each block excluded control block. Two (2) rates of fertilizer were used and standardized for each fertilizer. In order to conduct the economic analysis, data on yield monthly harvested and recorded to make it per hectare basis. Thus, the approaches for isolating the
benefits and costs of Intercropping O. stamineus with Rubber or Durian are based on 'With project' and 'Without project'. Economic criteria such as Net Present Value (NPV),
Internal Rate of Return (IRR), Benefit-Cost Ratio (BCR), Payback Period (PBP) and Sensitivity Analysis (SA) were analyzed for 20 years period project. From the computation of 20 years period projection, it is found that the NPV, IRR, BCR and PBP under durian at discounted factor rate 10% were RM91,751.00, 36.57%, 1.05 and 7 years for per hectare basis. Similar result also found under rubber were RM47,413.00, 55.45%, 1.04, 4 years. As a conclusion, the project intercropping of O. stamineus either under rubber and durian indicated economically feasible
Estimating aboveground carbon of teak-based agroforestry systems in Sabah, Malaysia using airborne LiDAR
Get PDFAs a sustainable land use system, agroforestry can potentially mitigate climate change mitigation by sequestering carbon and reducing greenhouse gasses (GHGs) emissions. Since the implementation of the Kyoto Protocol, agroforestry has been recognized as a GHGs mitigation strategy that requires accurate estimation of the carbon storage. Focusing on teak-based agroforestry systems in Sabah, Malaysia, this study examined the use of airborne Light Detection and Ranging (LiDAR) data for aboveground carbon (AGC) estimation. Field inventory data were collected at the agroforestry systems with different intercropping crops to calculate the field AGC. We derived height and canopy density metrics from the LiDAR data to correlate and regress with the field AGC. Stepwise multiple linear regression analyses resulted in a multivariate model that explains 88% of the AGC variance in the agroforestry systems. With the 25th and 55th height percentiles as predictors, the model had a cross-validated root-mean-square error (RMSEcv) of 6.12 Mg C ha-1 (Relative RMSEcv: 13.45%). As teak is one of the major plantation species in Southeast Asia, accurate LiDAR-based AGC estimation could assist in developing teakbased agroforestry systems for climate change mitigation in the region
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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