Judul: Keanekaragaman dan Pola Sebaran Spesies Tumbuhan Asing Invasif di Cagar Alam Pulau Sempu, Jawa Timur
Abstrak: The presence of invasive alien plant species has been known to cause various negative impacts on ecosystems in the invaded conservation area. This research aims to identify the diversity and distribution pattern of invasive alien plants species occurred in Sempu Island Nature Reserve, and to determine the most influential environmental factors to their dispersion. The methods used were the standard vegetation analysis and rapid assessment technique. According to the results, as many as 10 invasive alien plants species (belonging to 7 families) have been identified to occurred in this conservation area, e.g., Pistia stratoites, Ageratum mexicanum, Vernonia cinerea, Cyperus rotundus, Passiflora foetida, Centotheca lappacea, Eleusine indica, Imperata cylindrica, Hedyotis corymbosa, and Lantana camara. All invasive alien plant species found in the sampling plots had a clumped distribution pattern. The most influential environmental factors to the invasive alien plants dispersion were land slope and distance from shoreline.
Keyword: Sempu Island Nature Reserve, invasive alien plants, environmental factors, distribution pattern

Judul: Keanekaragaman dan Pola Sebaran Spesies Tumbuhan Asing Invasif Di Cagar Alam Yan Lapa
Abstrak: Invasive alien plants species were plant species which come from other regions or countries and gift negative impact to the native species diversity. This research aimed to identify the vegetation composition and structure, invasive alien plant species diversity, and distribution pattern of invasive alien plant species in Yan Lapa Nature Reserve. The methods used were vegetation analysis using combination of line transect and nested plot and rapid assessment. The most dominant family was Araceae. As many as twelve invasive alien plants species were identified exist in Yan Lapa Nature Reserve. Those twelve species were Acmella uliginosa, Ageratum conyzoides, Centotheca lappace, Cyathula prostrata, Paspalum conjugatum, Clidemia hirta, Chromolaena odorata, Elephantopus scaber, Mikania micrantha, Cecropia peltata, Swietenia macrophylla dan Lantana camara. All invasive alien plant species distribution patterns were clustered.
Keyword: Bogor Agricultural University (IPB), distribution pattern, invasive alien plants species, Yan Lapa Nature Reserve, Vegetation analysis

Judul: Sintesis dan Pencirian Natrium Titanat (Na2Ti2O4(OH)2) Berbahan Dasar Titanium Dioksida
Abstrak: TiO2 can be utilized as basic material for synthesis of sodium titanate (Na2Ti2O4(OH)2). This research was purposed to synthesize and characterize sodium titanate from TiO2 rutile powder as a basic material. Sodium titanate was synthesized by hydrothermal process at temperature 130 °C by mixing TiO2 rutile powder with 5 M and 10 M NaOH solution, then each was calcinated at temperature 700 °C. The energy dispersive X-ray analysis showed that sodium titanate has been successfully synthesized. This result was also supported by functional group analysis with Fourier transform infrared (FTIR) spectrofotometer showing the existence of Ti-O-Na vibration band at 989.42 cm-1. The formation of sodium titanate was depend on the reaction condition such as temperature, reaction time, and NaOH concentration. Scanning electron microscope image indicated that sodium titanate synthesized at 130 °C in 20 hours reaction time with 10 M NaOH had crystal size of 99.37 nm.
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