The Effect of Silvicultural Treatment on Stand Growth of Logged-over Forest in South Papua

Forest stand structure could be used as one of the variables in deciding the possibility to harvest forest product. On logged-over forests, data and information over stand structure could become the basis for decision making for harvesting. To measure and analyze yield on logged-over forest, each forest management unit (IUPHHK) is obligated to establish Permanent Sample Plots (PSPs) for monitoring the growth and yield of the managed stand. In some of the plots, maintenances and thinning treatments are applied while other plots are not treated. The results, after several years of observations, showed that there was a difference in stand structure (tree number) of each diameter class both in plots with treatment and without treatment. The rate of in-growth, up-growth and mortality varied between plots without and with treatment in each diameter class and length of time after harvesting. The average diameter increment of trees in the stands of the untreated plots was higher (0.60 cm yr-1) compared to the treated plots (0.55 cm yr-1)

Growth Model of Remmant Stands in Selectively Logged Forest, Papua

Sustainable forest management recently calls for growth information concerning integrated functions of ingrowth, upgrowth and mortality. This study was conducted in logging concessions of PT. Tunas Timber Lestari (TTL), PT. Wapoga Mutiara Timber (WMT) dan PT. Manokwari Mandiri Lestari (MML) in Papua. Then, this research was intended to build growth stands models in logged over forest. The data were obtained from permanent sample plots (PSPs) in three logging concession in Papua forest. Results revealed that characteristics of stand namely basal area, stem density and diameter had significant coefficients to model of ingrowth, upgrowth and mortality in each logging concession. Specifically, PT WMT showed the highest value of coefficient of determination (>80%, P<0.05). For PT MML only had significant model namely ingrowth and upgrowth model while PT TTL only shwed ingrowth model as significant equation

Model Pertumbuhan Tegakan Hutan Alam Bekas Tebangan dengan Sistem Tebang Pilih di Papua

Sustainable forest management recently calls for growth information concerning integrated functions of ingrowth, upgrowth and mortality. This study was conducted in logging concessions of PT. Tunas Timber Lestari (TTL), PT. Wapoga Mutiara Timber (WMT) dan PT. Manokwari Mandiri Lestari (MML) in Papua. Then, this research was intended to build growth stands models in logged over forest. The data were obtained from permanent sample plots (PSPs) in three logging concession in Papua forest. Results revealed that characteristics of stand namely basal area, stem density and diameter had significant coefficients to model of ingrowth, upgrowth and mortality in each logging concession. Specifically, PT WMT showed the highest value of coefficient of determination (>80%, P<0.05). For PT MML only had significant model namely ingrowth and upgrowth model while PT TTL only shwed ingrowth model as significant equation

Population Structures of Four Tree Species in Logged-over Tropical Forest in South Papua, Indonesia: an Integral Projection Model Approach

Selective logging has been taking place in Papua for several decades. In contrast, very little is known about the stand structure in post-logged forest. Hence, this paper investigates stand structures in logged-over area of tropical forest in South Papua. Four species were selected in three one-hectare permanent sample plots (PSPs): Vatica rassak, Syzygium sp, Litsea timoriana and Canarium asperum. PSPs were located in the forest concession area of PT. Tunas Sawaerma in Assiki, Boven Digul, in South Papua. Data sets comprised measurements made in 2005 and 2012 consisting of species, diameter at breast height (DBH), mortality and number of tree of each species. Integral Projection Models (IPMs) were developed, taking into account mortality, growth, recruitment and fecundity. Results show the pattern of stand structures of the four species were more or less similar, i.e. more individual trees were present in the small diameter classes than in the larger diameter classes. The general pattern of the individual distribution of the four species is the typical reverse-J shape. Syzygium sp. has a greater number of individuals in the small diameter classes than the other three species. Population growth rates (λ) are above one, indicating that the stand structures of the population dynamics of the four species are recuperating. Conclusively, these results suggest that species composition and population structure in these logged-over forests are recovering increasingly

SIMULASI PEMISAHAN SISTEM BINER DENGAN DISTILASI BATCH SEDERHANA

A simulation on separating binary system has been studied to investigate the temperature and liquid compositions profiles in the bottom changing with time. By having temperature and liquid compositions profiles in the bottom, one can find whether the binary mixture forms azeotropes or zeotropes mixtures. Antoine equation has used to calculate saturated vapour pressure at atmospheric pressure. The activity coefficient was calculated using UNlQUAC. Forward finite-difference was used to get the calculated value of the bottom still composition at a given time starting from a given initial composition of binary system. Several initial values of the composition binary system had been chosen to complete liquid compositions in the bottom. The results showed that the temperature profiles of acetone-n-butanol and ethanol-n-butanol binary system have differences characteristic from acetone-ethanol binary system. Those can be seen from activity coefficient profile. The results showed that the binary system formed zeotropes mixture, without having any azeotropes mixtures of its components. The results simulation on separation binary system has been validated with hydrocarbon binary system benzene-toluene mixture

Pengembangan Bahan Ajar Digital Berlandaskan Model Guided-project Based Learning

Observation results showed SMK Negeri 1 Beji Pasuruan has been used digital material and project based learning method. Purpose development is to produce digital material on subject shooting moving image techniques based guided-project based learning in SMK Negeri 1 Beji Pasuruan. Research and development model is used adapting Dick &amp; Carey'model which modified by eliminating formative evaluation. Subjects trial test are matter expert, media expert, teacher, and student 12th grade. Average feasibilities get 89,5% and result post-test get 81,77. Suggest furthermore development is adding four projects that can be one integrity materials in one years periode and = effectivity tests.Hasil observasi menunjukkan SMK Negeri 1 Beji Pasuruan sudah menggunakan bahan ajar digital dan project based learning dalam pembelajaran. Tujuan pengembangan menghasilkan bahan ajar digital pada mata pelajaran Teknik Pengambilan Gambar Bergerak berlandaskan model Guided-Project Based Learning di SMK Negeri 1 Beji Pasuruan. Model penelitian dan pengembangan mengadaptasi model Dick &amp; Carey yang dimodifikasi dengan menghilangkan evaluasi formatif. Subjek uji coba ahli materi, ahli media, guru, siswa kelas XII. Rata-rata kelayakan sebesar 89,5% dan pencapaian post-test sebesar 81,77. Saran pengembangan lebih lanjut dengan menambahkan empat proyek sehingga menjadi satu keutuhan bahan ajar dalam periode satu tahun dan perlu uji efektivitas

Penggunaan Multimedia Interaktif Bermuatan Game Edukasi untuk Meningkatkan Aktivitas dan Hasil Belajar Siswa Sekolah Dasar

This study aims at producing fit and proper, feasible, effective, and interesting interactive multimedia. Based on the result of fit and proper analysis, it was obtained 76.64 % (fit and proper), feasibility is 88.87 % (very feasible), effectiveness is obtained from the obsememrvation result and it shows that there is an improvement in students\u27 learning activity about 85.05% (very good), for the mean of post-test is 80.19 and interest analysis is 92.72% (very interesting). From the result of this research, it shows that interactive multimedia is fit and proper to be used as a learning media.Tujuan penelitian ini untuk menghasilkan multimedia interaktif yang layak, praktis, efektif, dan menarik. Berdasarkan hasil analisis kelayakan diperoleh persentase sebesar 79,64% (layak), kepraktisan sebesar 88,87% (sangat praktis), keefektifan dari hasil observasi menunjukkan bahwa ada peningkatan aktivitas belajar siswa dengan perolehan persentase sebesar 85,05% (sangat baik), dari nilai pascates siswa diperoleh perhitungan rata-rata 80,19, dan kemenarikan mendapat persentase sebesar 92,72% (sangat menarik). Hasil penelitian menunjukkan bahwa multimedia interaktif ini layak digunakan sebagai media dalam pembelajaran

Tsunami force on low building and the effect of surrounding buildings

Today tsunami hazard has become an important aspect in national security of Indonesia and generated many researches. Tsunami disaster in the Hindian Ocean 2004 has caused a lot of buildings damaged and probably the greatest loss of lives ever due to tsunami. This research aims to analyze the tsunami force acting on the low building or overtopping building and the effect of other buildings nearby. The research was conducted using physical model at the Hydraulic and Hydrology Laboratory, Research Centre for Engineering Science, Gadjah Mada University Yogyakarta. The physical model simulations were carried out in the wave flume of 24 m long, 1.5 m high, and 1.45 m width that was facilitated with tsunami generator based on dam break system. The buildings were placed in a row perpendicular to tsunami wave flume. The distances between the buildings were varied to observe the effect of such opening on the impact. The physical simulation represented the tsunami attack in Aceh in 2004, where the houses and other low structures were overtopped by tsunami. The building models were made of plywood. Data acquisition was carried out using a load cell to measure the total force on the building. The results shows that the maximum force depends on the opening between the buildings and that higher building nearby gave more impact to the building investigated. Simple equations for practical use are proposed to calculate the tsunami force on the overtopping building with the effect of the surrounding buildings