Judul: Daerah Jelajah dan Model Kesesuaian Habitat Harimau Sumatra (Panthera tigris sumatrae) Pasca Translokasi
Abstrak: Harimau Sumatra merupakan mamalia yang terancam punah di Indonesia. Oleh karena itu, harimau memainkan peran pengaturan yang penting dalam menjaga ekosistem yang sehat dengan memberikan tekanan dari atas ke bawah terhadap komunitas mangsa dan kepunahannya dapat menyebabkan dampak negatif. Translokasi menjadi pilihan ketika lokasi konflik sudah tidak memungkinkan lagi sebagai habitat harimau, perubahan lanskap dari homogen menjadi heterogen menyebabkan perubahan keanekaragaman hayati yang berdampak pada perubahan sumber daya. Kajian ekologi tentang aspek pemanfaatan ruang dan karakteristik kesesuaian habitat oleh harimau yang ditranslokasikan perlu dilakukan untuk membesar peluang hidup. Namun demikian, area yang cocok bisa berubah menjadi lebih baik atau lebih buruk berdasarkan keberhasilan pengelolaan habitat. Penelitian ini bertujuan untuk menganalisis daerah jelajah dan pemilihan daerah yang sesuai berdasarkan metrik lanskap oleh harimau translokasi. Harimau translokasi barasal dari barumun nagari hasil perkembang biakan secara alami. Pengumpulan data titik kehadiran kalung GPS di setting satu jam dilakukan pada bulan Juni–September 2022 di Taman Nasional Kerinci Seblat . Penelitian dilakukan melalui pengembangan model sebaran spesies dengan menggunakan program Minimum Convex Polygon (MCP), Fixed kernel (FK) dan model Maximum entropy (Maxent) dengan variabel lingkungan lanskap indeks dan topografi yang di dapatkan dari peta tutupan lahan yang di klasifikasikan. Metode-metode ini sangat berguna untuk penilaian skala besar dan dapat memberikan informasi berharga mengenai dinamika fragmentasi hutan. Waktu paling aktif harimau ada pagi hari (06.00-08.95) harimau sumatra translokasi menggunakan habitat utama dengan proporsi yang sama baik pada siang maupun malam hari. Menggunakan metode MCP mendapat wilayah jelajah 492,60 km2 dan 95% Fixed Kernel diperkirakan ukuran daerah jelajah jantan antara 12,48 km2 . Hasil pengamatan menunjukkan bahwa harimau translokasi tidak menjadikan areal pelepasliarannya sebagai bagian dari daerah jelajahnya. Mereka membangun daerah jelajahnya pada jarak 14,64 km dari lokasi dimana mereka dilepas-liarkan. Karakteristik habitat yang disukai harimau translokasi adalah lansekap mosaik hutan sekunder perpaduan antara hutan dataran rendah yang berada pada elevasi di bawah 1.000 meter dpl. Penelitian ini menghasilkan pemodelann harimau sumatra dengan nilai AUC 0,88 dan standar deviasi 0,011 artinya berkinerja baik yang bisa digunakan untuk mengukur presence dalam model prediksi kehadiran harimau sumatra. Hasil penelitian ini juga mengidentifikasi dan memetakan habitat harimau di TNKS sehingga menghasilkan habitat sesuai dengan luas 485.424 ha (35,78%) dan habitat tidak sesuai dengan luas 871.322 ha (64,22%) dari luas. Kontribusi total tepi hutan sangat dominan dengan proporsi pada model ini sebesar 35,5% dan proporsi luas kelas 27,5%. Keberadaan dan susunan demografi harimau lokal di lokasi pelepasliaran, serta kecukupan ketersediaan satwa mangsa utama harus menjadi bahan pertimbangan dalam pelepasam. Sangat penting untuk memastikan bahwa lokasi translokasi potensial bebas dari gangguan manusia yang dapat membahayakan harimau karena beberapa harimau sumatra yang ditranslokasi telah terbunuh oleh jerat (baik yang dipasang oleh masyarakat untuk melindungi ladang dari hama babi hutan maupun yang sengaja dipasang oleh pemburu). Sebelum translokasi harimau dimulai, perlu juga dilakukan penilaian sosial terhadap lingkungan di sekitar lokasi translokasi. Kata kunci: harimau sumatra, kesesuaian habitat, maxent, pergerakan, pemodelan spasial
Keyword: habitat suitability, maxent, movement, spatial modeling, sumatran tiger, harimau sumatra, kesesuaian habitat, pergerakan, pemodelan spasial

Judul: Pola penggunaan ruang dan model kesesuaian habitat harimau sumatera (Panthera tigris sumatrae Pocock, 1929) pasca translokasi berdasarkan pemantauan kalung GPS
Abstrak: Panthera tigris sumatrae is the last remaining Indonesian tiger after its relatives, the Bali and Javan tigers, became extinct in 1940s and 1980s respectively. Although translocation has been employed in mitigating human-tiger conflict in Sumatra for the last decade, the behavioral ecology of post-release animals is still poorly understood. Furthermore, the spatial modelling of tiger behavior based on global positioning system (GPS) collar tracking has never been done before. This information is urgently needed for improving Sumatran tiger translocation in the future. In this study we examine the movement and home range, activity pattern, and habitat selection of translocated tigers, as well as construct a habitat suitability model for identifying appropriate sites for future tiger translocation in Ulu Masen forest. Between July 2008 and December 2010 we translocated six Sumatran tigers, five males and one female. All tigers were fitted with GPS collars which were set to fix 24-48 location coordinates per day. The logistic regression equation was used to produce the habitat suitability prediction models and the tiger distribution map was overlaid with data on the relative abundance of tiger prey to determine suitable sites for future translocation. The mean distance traveled by the tigers varies from 2.8 to 4.0 km per day, but the female moved further than the males. In general, there was no difference in the mean distance traveled between day-time and night-time among the males, but the female traveled further in the day-time than during night-time. The length of time needed by each tiger to establish home range was significantly affected by the abundance of local tigers already in the area. The home range of each individual tiger, estimated using 95% fixed kernel, varies between 37.5 km2 and 188.1 km2 for males while for the female it was 376.8 km2. The most active period for translocated tigers is in the evening between 6 and 10 pm. However, on certain occasions, the tigers are most active in the morning between 6 and 10 am. The translocated tigers tend to range across all natural land cover types within the landscape, but forest availability within the landscape remains important for their survival. However, it seems that all translocated tigers prefer to conduct their daily activity within the mozaic landscape of lowland forest and regrowth vegetation. Modelling has shown that elevation, distance from rivers, distance from the edge of the forest, density of the forest canopy, and the slope of the terrain significantly influence the habitat model. Extrapolation of the model to the whole area of Ulu Masen forest (7,496.86 km2) has indentified 23.5% of the area as highly suitable habitat, 71.5% as suitable habitat, and 5.0% as less suitable habitat for the Sumatran tiger. It is also predicted that 5.2% of the ecosystem is highly suitable for future tiger translocation. Despite being preliminary, the findings of this study, the first ever conducted in Sumatra, highlight the conservation value of tiger translocation and provide valuable information for improving future translocation of rescued tigers.
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Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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