Judul: Validation of Global Allometric Models for Estimating Various Tree Species in Indonesia
Abstrak: Pendugaan biomassa hutan seringkali menggunakan model alometrik global ketika model alometrik lokal tidak tersedia. Namun, belum banyak pengujian akurasi model alometrik global untuk pendugaan biomassa pohon. Penelitian ini bertujuan menguji keakuratan model alometrik global (yaitu model Chave dan Komiyama) untuk pendugaan biomassa pohon pada hutan lahan kering sekunder, hutan tanaman, dan hutan mangrove sekunder di Indonesia. Penelitian ini menggunakan metode studi pustaka, data biomassa pohon diperoleh dari pustaka yang telah dipublikasikan. Keakuratan pendugaan biomassa dari model alometrik global dinilai dengan menghitung beberapa nilai statistik (yaitu ME, PE, RMSE, dan MAPE), semakin kecil nilai statistik, semakin tinggi akurasi model alometrik global. Hasil penelitian menunjukkan bahwa model alometrik global Chave yang menggunakan variabel kerapatan kayu, diameter pohon, tinggi pohon lebih akurat untuk pendugaan biomassa pohon di hutan lahan kering sekunder, sedangkan model alometrik global Chave yang menggunakan variabel kerapatan kayu dan diameter pohon lebih akurat untuk menduga biomassa pohon hutan tanaman. Model alometrik global Komiyama lebih akurat untuk menduga biomassa pohon hutan mangrove., Estimation of forest biomass often uses global allometric models when local allometric models were not available. However, there have not been many tests on the accuracy of global allometric models for estimating tree biomass. This study aimed to test the accuracy of global allometric models (i.e. Chave and Komiyama models) for estimating tree biomass at secondary dryland forests, plantation forests, and mangrove forests in Indonesia. This study used a literature review method, where tree biomass data were obtained from published literatures. The accuracy of biomass estimation from the global allometric models was assessed by calculating some statistical values (i.e. ME, PE, RMSE, and MAPE), in which the smaller the statistical values, the higher the accuracy of the global allometric models. The results showed that the Chave's global allometric model, which uses wood density, tree diameter, tree height variables, was more accurate for estimating tree biomass of secondary dryland forests, while the Chave's global allometric model that use, wood density and tree diameter variables was more accurate for estimating tree biomass of plantation forests. The Komiyama's global allometric model was more accurate for estimating tree biomass of mangrove forests.
Keyword: Bias, Tree Biomass, Validation, Allometric Model

Judul: Model Persamaan Alometrik Penduga Biomasa Hutan Alam Tropika di Areal IUPHHK-HA PT. Wapoga Mutiara Timber, Papua
Abstrak: This research aims to create allometric equation models to estimate the biomass of tropical natural forests in eastern Indonesia. Allometric equation models made by destructive methods and using purposive sampling method to take 30 sampling trees. Best equation model to estimate tree biomass of this research consists of biomass tree parts model and total tree biomass model. Models to estimate the biomass of the tree parts such as W = 0.0245 D2,23 Tt0,74 to estimate the stem biomass, W = 0,0003 D3,91 Tbc-0,66 for the branch biomass, W = 0,054783 D2,42 Tt-0,63 for twigs biomass, and W = 0,0513 D1,62 for leaf biomass. The best model to estimate the total biomass is W = 0,0655 D2,52Tbc0,23 where W is biomass, D is diameter at breast height (cm), Tbc (clear bole), and Tt is the total height of the tree. This models have R2(adj) of 78,31 – 97,75% and the deviation (s) of 0,1337 – 0,3201.
Keyword: tropical natural forests, forest biomass, Allometric models

Judul: Struktur dan Karakteristik Optik Lapisan Semikonduktos Cu2O (Cuprous oxide) Hasil Deposisi Elektrokimia
Abstrak: Ballan semikonduktor Cu2O (Ctiprotis oxide) dipilih karena lnemiliki banyak keuntungan antara lain ; relatif murah, bahan dasar (Cu) mudah didapat, dan tidak beracun. Banyak metode deposisi telah digunakan untuk menghasilkan lapisan semikonduktor Cu,O, dalam penelitian ini digunakan metode deposisi elektrokimia. Deposisi elektrokimia dilakukan scbanyak dua salnpel dengan variasi tegangan -500 mV (sampel I ) dan 4 0 0 mV (sampel 2) terhadap SCE. Lapisan selnikonduktor Cu20 diatas kaca TCO yang dihasilkan dikal-akterisasi kristalografi (XRD), morfologi (SEM), dan optiknya (Spektrofotometer UV-VIS). Melalui karakterisasi XRD diketahui semikonduktor Cu20 yang terbentuk adalah polikristal.
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