Jurnal Manajemen Hutan Tropika
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Keragaman Struktur Tegakan Hutan Alam Sekunder (The Variability of Stand Structure of Logged-over Natural Forest)
Get PDFDifferences in logging intensity, forestfires and forest encroachment have caused the variability of natural forest conditions, including its horizontal and vertical stand structures. Information on stand structure variability and dynamic of secondary forests is essential for projecting the future stand structure, which can be used to develop forest management plan. This study, which used 109 permanent sample plots data established on low and dry-land logged over natural forests in Kalimantan, showed that there was an obvious variability of the stand conditions after logging in terms of the trees number per hectare and horizontal stand structures
Pengaruh Perapihan pada Berbagai Stratifikasi Hutan Lepas Tebang terhadap Permudaan
Get PDFThe study of the effects of the clean activities of forest layers in logged areas on the increments of forest value comprises measurement by aerial photograph with scale of 1 : 20.000 and measurement in the field. The stand parameters measured are the percentage of crown cover (C), tree height (H) and crown diameters (D). Whereas, forest values are defined through the measurements of the amounts and qualities of rejuvenations counted after 1 year, 3 year, and 5 year of tidiness. The forest stratums resulted were Cl = 211.6 ha; C2 = 492.0 ha; and C3 = 196.4 ha. The t test conducted in every stratum showed that the tidiness affected significantly on the the amounts and qualities of rejuvenations. It could be concluded that the clean up activities increased the forest values
Sources of Timber and Constraints to the Timber Acquisition of Jepara‘s Small-Scale Furniture Industries
Get PDFTeak and mahogany furniture industries in Jepara are dominated by small-scale industrial unit, produce simple type of furniture mostly made from less than 28 cm diameter of teak log. Timber main producers of the industries are Perum Perhutani and village plantations. Small-scale furniture industries characterized by limited capital, therefore there is no log stocking behavior. This resulted in a close interaction on log supply and demand dynamics between both traders and industries. As a consequence of drastic increase in the number of the industries, one big question on sustainability of raw material for the industries has been emerged. Data taken from this research indicated scarcity of teak and mahogany log. Limited capital directs industries to blame the difficulties mainly due to increasing timber price. Additionally, the industries (and log traders) who are stand mostly in level 2 of log distribution chain mentioned that compared to 10 years ago, there is difficulty in obtaining bigger log diameter. It is a very interesting finding that the industries do not certainly sense timber scarcity as one possibility reason behind the timber scarcity. As weakness on business resilience has been the main characteristic of the industries, the threads would give a direct impact to the industries soon or later. To this, serious efforts in maintaining timber sustainability, shortening timber distribution chain, together with capital strengthening seem to be the fastest way in supporting the sustainability of the industries.Keywords: teak furniture, timber price, small-scale, timber scarcit
Insentif Ekonomi dalam Penggunaan Lahan (Land Use) Kawasan Lindung di Kawasan Bandung Utara (Incentive of Economy for Land Use in The North Bandung Area)
Get PDFWest Javanese Province Goverment has decided to provide 45% of West Java area as conservation and protection area. One of the area is North Bandung Area (KBU: Kawasan Bandung Utara). This paper proposed the used of two economic instrument, namely PDR (purchase development right) and PES (payment environment service) in managing the KBU. The paper shows that the use of PDR by ignoring the price of the land would give a hydrological benefit to the people in urban fringe area, rural fringe area, and rural area in the netx 20 years. Meanwhile, the use of PES intruments with incentive application to plant out tree at estate conservation (both forest and non forest land) would provide benefit for minimum 24 years renting period. Further, the analysis shows that the PDR and PES implementation at 4 regencies/city government at KBU should be considered as a good prospect, even though seeing from the finances aspect of APBD, the prospect was still less than the target. Therefore, continous finance policy support at the regencies/city government at that KBU which aimed to provide environmental protection and agricultural farm (pro-environmental budgeting policy) should be considered as emergency needs.Keywords: conservation area, land use, economic incentive, PDR, PES
Genus Fungi pada Tanah Hutan Mangrove Tercemar Logam Berat di Muara Angke DKI Jakarta
Get PDFMangrove soils in Muara Angke Jakarta were suspected to be polluted with heavy metals. This study describes the analysis to the heavy metal content in those polluted soils. The fungus on those soils was isolated and identified. Results show that heavy metal content of soils of Muara Angke was high, i.e., 1.53 ppm for Pb, 4.59 ppm for Cu and 22.55 ppb for Hg. The fungi that were isolated included Penicilium sp., Eupenicillium sp., Talaromyces sp., Aspergillus sp., Trichoderma sp., and sterile fungi, i.e., fungi that did not produce conidia on PDA medium
Kandungan Fosfor dan Kalsium pada Tanah dan Biomassa Hutan Rawa Gambut (Studi Kasus di Wilayah HPH PT. Diamond Raya Timber, Bagan Siapi-api, Provinsi Riau)
Get PDFResearch on the biomassa, distribution and content of P and Ca nutrients in the soil and biomass was conducted in a primary forest with peat thickness ranging between 2.5 to 6.5 m in the forest concession area (HPH) of PT. Diamond Raya Timber, Bagan Siapi-api, the Riau Province. The objective of the research was to obtain data on the content of P and Ca in the vegetation and peat soil layers at several levels of peat thickness. Research results showed that although vegetation biomass constituted only 6 % of the total biomass of vegetation and peat soil, contain of P nutrient as much as 37 % and Ca 28 % out of the total P or Ca nutrients occurring in vegetation and peat soil. Increasing of peat thickness because the total content of nutrients in the peat soil also increased, although the average content of nutrient per depth interval of 50 cm decreased. Increasing of peat thickness alse increased the content of P or Ca for tree stage vegetation, on the other hand, the content of P or Ca in herbs and shurbs, decreased. This phenomenon shows that on peat thickness more than 3 m only higher vegetation (trees vegetation) could survive properly. Contetnt of P or Ca nutrients occuring at above ground tree stage vegetation reach 64 % and 74 %. While for tree stage vegetation, the biggest nutrient content occurred in branches, nas follows 44 % foer P and 40 % for Ca. Pioneer trees species and lesser known timber in fact had the highest P and Ca elernent concentration. For the highest Ca elements were in timah-timah (Ilex bogoriensis- 14,02 g kg-1), milas (Parastemon urophyllum,13,72 kg-1) and suntai (Palaquium dasyphyllum; 13,13 g kg-1). While for P element of beringin (Ficus benyamina;20,1 g kg-1), punak (Tetramerista glabra; 1,91 g kg-1) and terentang (Camnosperma macrophylla; 1,59 g kg-1)
Volume Estimation of Standing Shorea sp. on UPM-JISE Rehabilitated Forest in Bintulu, Sarawak
Get PDFThis study was aimed to analyze the relationship between diameter at breast height, height, and volume of standing Shorea sp. and the relationship between age and volume of this species. The study was conducted at different ages of rehabilitated forest in Bintulu Sarawak, where the measurement was taken from tree stand year 1992 until 2003. The sampling plot of 20m x 20m was built for each age of stand. Ten standing Shorea sp. were randomly measured for sectionals (taper) from diameter at breast height until the free branches of the tree. The rest of the trees within the plot were only measured by diameter at breast height. All collected data were calculated to find basal area of each tree in meter square (m2). The volume per plot was calculated using the Smalian’s formula to find the taper volume of the Shorea sp. Statistical analysis was conducted to find the regression equation which could explain the relation between volume, diameter, and height of the tree. Result showed that there was a relationship between volume, diameter, and height of the tree, and also there was relationship between volume and age of the tree. Meanwhile, there was no relationship between taper of standing trees and age of trees. This means that volume taper of standing tree and age have no correlation
Penggunaan Analisis Regresi Terboboti dalam Penyusunan Model Pertumbuhan Peninggi Acacia mangium Willd.
Get PDFThe compilation of growth stand model usually uses the regression analysis. Homoscedasticity or residual kind homogeneity is one assumption which underlying the use of this regression analysis. Breaking this assumption causes the low of model accuracy which is shown by the low of determination coefficient and the height of error standard. The problem of heteroscedasticity can be solved by using weighted regression analysis.The Selected Raiser Growth Model equation in this research was transformed into a model equation: ln P = a + b/A, where there was a significant correlation between the growth and the age (R2 = 55.04%, sb0 = 0.041, and sb1 = 0.171). From the use of weighted regression analysis with weightier wi = 1/”Xi, it can be concluded that there was no real correlation between the growth and the age (R2 = 0.55%, sb0 = 0.572, and sb1 = 2.560). The use of weightier shows much lower accuracy than without weightier. However, from the use of weighted regression analysis with weightier: wi = 1/si2, where si2 = residual kinds at free variable group to I (X1) shows that there was significant correlation between the growth and the age (R2 = 45.46%; sb0 = 0.084, and sb1 = 0.205). There fore it can be said that the accuracy was much better than regression without weightier. Furthermore, the use of weighted regression analysis with weightier wi = 1/si2, where si2 is residual kind at free variable to i (X) which is estimated through second orde polynomial regression model shows a very significant correlation between the growth and the age (where R2 = 87.22%, sb0 = 0.029, and sb1 = 0.072). The last result shows a better accuracy than the preceding treatments. From this research, it can be concluded that by using a suitable weightier, the use of weighted regression analysis in compiling raiser growth model can improve the model accuracy
Keragaman Avifauna pada Lahan Bekas Tambang Emas PT Kelian Equatorial Mining, Kutai Barat Kalimantan Timur (Variety of Avifauna on Land Ex-Gold Mining PT Kelian Equatorial Mining West Kutai, East Kalimantan)
Get PDFThe presence of birds’ species on the land ex-gold mining in PT Kelian Equatorial Mining West Kutai, East Kalimantan becomes a good indication for the future of the rehabilitation area. The existence of natural forest in surrounding of rehabilitation area is a source of species for this rehabilitation area. The difference and the similarity of species between natural forest (Dam Namuk) and rehabilitation area (Lower Nakan) show that the primary species start doing occupation in rehabilitation area. The monitoring to the selected species (dominant or rare) needs to be implemented in the future to make sure the success of the rehabilitation area as a good habitat provider for many birds’ species.Keywords: avifauna, rehabilitation, natural forest, habita
Growth of Gmelina Seedling with Various Compost Fertilizer in Ex-Gold Mining Land Media
Get PDFMining activities could have negative impacts on the environment if the tailings produced were not processedproperly. Non-economic tailing is a composite of various minerals (heavy metal) with sandy texture. Environmental impacts that might occur as a result of poor processing of tailings is a disruption of natural ecosystems as indicated by a decline in quality and productivity of the environment as a result of changes in soil morphology and physical properties, chemical, and biological properties. One vegetative technique that could be applied to rehabilitate degraded land is re-vegetation with the application of fertilizer. Compost could improve the physical properties, chemical, and biological properties of soil. Compost was also an agent of bioremediation so that toxic heavy metals elements in growing medium could be eliminated or reduced. The experimental design used in this study was Completely Randomized Design with compost applications consisting of 4 levels of treatment with each level of treatment consisting of 3 replications, each replication consisted of one gmelina seedling. Research showed that the application of compost would significantly affect the growth of gmelina’s height, but not significantly affected the diameter growth. Single-dose effect of 30 g of compost would significantly affect the seedling’s height. The combination of planting and fertilizing glemina using compost could be recommended in an effort to reclaim land of ex-gold mining.