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: GIS dan Remote Sensing untuk Analisis Kesesuaian Habitat Harimau Sumatera (Panthera tigris sumatrae) di Taman Nasional Bukit Tigapuluh dan Sekitarnya
Abstrak: Sumatran tiger is one of eight sub-species tiger in the world. Their distribution is limited in island of Sumatra. Their habitat and population are threatened by land conversion activities and also legal and illegal logging. Bukit Tigapuluh National Park is part of Bukit Tigapuluh landscape. This area is designated as a global protection priority area for sumatran tigers. Therefore, it is an urgent need to study their habitat suitability for management purposed. Geographical Information System and Remote Sensing can be used to achieve the objective. It can be applied for large area scale. This study aims to identify broad areas that are still suitable for tiger habitat. In the same time they can be utilized also to clarify the impact of land use change on sumatran tiger habitats. The logistic regression equation was used for habitat suitability prediction models. Logistic regression utilized presence and pseudo-absence data. Presence of tiger indicated by location of the camera trap that catched tiger as well as secondary markers, such as traces, scrape and dirt. Pseudo-absence data was set randomly at a buffer outside the area of presence. One hundred and six pairs of presence and pseudo-absence data used in this study. Environmental data was obtained from digital maps, ASTER GDEM, and Landsat 5TM. Six predictor variables were used including elevation, slope, distance from river, distance from roads, distance from settlements and NDVI. Research results indicated that altitude, slope, distance from rivers and NDVI have a significant influence on the models. Habitats with low suitability (198.351,99 ha) was greater than medium suitability (54.213,30 ha) and the high suitability is 264.619,71 ha. Extrapolation models on the time sequence image shows the influence of forest land cover changes on the appropriate area for tiger habitat.
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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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