Judul: Forest Cover Change and its Influencing Factors in  Nabire Regency.
Abstrak: Studi ini menganalisis perubahan tutupan lahan dan faktor-faktor yang mempengaruhi degradasi hutan di Kabupaten Nabire, Provinsi Papua Tengah. Dalam 20 tahun terakhir, telah terjadi penurunan luasan dan kualitas habitat hutan yang signifikan, terutama akibat aktivitas manusia seperti konversi lahan untuk perkebunan. Penelitian ini dilakukan selama 15 bulan, dari Februari 2022 hingga April 2023, dengan menggunakan peta tutupan lahan tahun 2000, 2009, dan 2019 serta metode analisis Geographically Weighted Regression (GWR) untuk mengidentifikasi faktor-faktor yang berkontribusi terhadap degradasi hutan. Hasilnya menunjukkan bahwa telah terjadi perubahan tutupan lahan yang signifikan selama dua dekade terakhir. Hutan lahan kering primer mengalami penurunan yang signifikan, sementara semak belukar, semak belukar rawa, dan perkebunan mengalami peningkatan. Analisis GWR menunjukkan bahwa kepadatan penduduk, jarak ke pusat pemerintahan, pemukiman, jarak ke terminal, dan jalan raya merupakan faktor utama yang mempengaruhi degradasi hutan. Ditemukan bahwa degradasi hutan yang paling signifikan terjadi di distrik Teluk Umar dan Yaur. Pengelolaan adaptif direkomendasikan untuk pengelolaan hutan berkelanjutan, termasuk rehabilitasi lahan kritis, evaluasi kebijakan yang adaptif, dan pengelolaan, termasuk rehabilitasi lahan kritis, evaluasi kebijakan yang adaptif, dan pemeliharaan basis data pengelolaan hutan yang komprehensif. Pendekatan ini diharapkan dapat mengurangi degradasi hutan dan mendukung keberlanjutan ekosistem hutan di Kabupaten Nabire., This study analyzes land cover changes and factors affecting forest degradation in Nabire Regency, Central Papua Province. In the last 20 years, there has been a significant decline in the area and quality of forest habitat, mainly due to human activities such as land conversion for plantations. This study was conducted over 15 months, from February 2022 to April 2023, using 2000, 2009, and 2019 land cover maps and the Geographically Weighted Regression (GWR) analysis method to identify factors that contribute to forest degradation. The results show that there have been significant land cover changes over the past two decades. Primary dryland forests experienced a notable decline, while scrub, swamp scrub, and plantations experienced an increase. GWR analysis showed that population density, and distance to government centers, settlements, distance to terminals, and roads were the main factors affecting forest degradation. It was found that the most significant forest degradation occurred in the Teluk Umar and Yaur districts. Adaptive management is recommended for sustainable forest management, including rehabilitation of critical lands, adaptive evaluation of policies, and management, including rehabilitation of critical lands, adaptive evaluation of policies, and maintenance of a comprehensive forest management database. This approach is expected to reduce forest degradation and support the sustainability of forest ecosystems in Nabire Regency.
Keyword: adaptive management, degradation, land use/cover change

Judul: Strategi Pengendalian Degradasi Hutan di Taman Nasional Gunung Halimun Salak
Abstrak: Forest degradation can be defined as changes within the forest which negatively affect the structure or function of the stand or site, and thereby lower the capacity to supply products and/or services. The process involving the canopy quality decrease and forest structure in a long term. Therefore, to detect and manage the rate of degradation, satellite remote sensing provides the capabilities to monitor it time effectively. Forest degradation caused by interaction of many factors, hence driving factors analysis required to arrange the strategy of forest degradation management. The aim of this study is to analyze the forest degradation within the Halimun Salak National Park (TNGHS). The specific objectives of the study are 1) to detect the forest degradation level by canopy cover as the indicator, 2) to assess the forest degradation driving factors, and 3) to arrange the forest degradation management strategy in TNGHS. The forest canopy density (FCD) method was used to detect the degradation by percentage of canopy cover as the indicator. The canopy cover was devided in 4 cover density class, i.e non forest (0-10% canopy cover), low density forest (11-30%), moderate density (31-50%) and high density forest (51-100%). Decreasing among the forest density class hereinafter appointed as slightly degraded forest, severely degraded forest, and deforestation. The spatial analysis result showed that among 2003 – 2007 degraded forest cover a total area of 5005,71 Ha, while slightly degraded forest occupied for 2764,80 Ha, deforestation 1493,46 Ha and severely degraded forest is 747,45 Ha. Then, among 2003 – 2011, indicates that the area interpreted as deforestation had becoming less than before. This can be caused by vast cloud coverage in 2011 imagery, also rehabilitation and restoration in open area, so in time of data interpretation the visibility of vegetation cover identified as forest canopy cover. During 2003 – 2011 period, the result showed that slightly degraded forest occupied for 6197,13 Ha, severely degraded forest for 1200,15 Ha, and deforestation for 189,9 Ha. Stepwise regression was used to assess the driving factors affecting the total area of forest degradation. The observation unit is village (Desa) within the study site. Based on regression technique, the distance to the sub-district (Kecamatan) is the most important variable for forest degradation total area. The other significant factors are population growth, growth of build up area (non agriculture area), and percentage of amount agriculture household. Distance to the sub-district and growth of build up area show that there is space utilization, both inside the park or regency administrative area. While, population growth and amount of agriculture household are underlying process which drive the change of space utilization pattern and intensity, so that lead to allocation changing for every land use to support the region growth to fulfill the population need. Considering that TNGHS presence as both cross-section and interest stakeholders, then the regulation establishment is needed first in term the space utilization, due to its important role to control or manage the forest degradation driving factors. In arrangement of the strategy, degradation management focus was determined by the role and implementation of regulation and policy related
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Judul: Reproduksi Ikan "Shirogisu" Sillago japonica (Temminck dan Schlegel) di Perairan Teluk Omura, Nagasaki, Jepang
Abstrak: Ikan S. japonica pertama kali matang gonad pada ukuran kelas panjang 185 - 198 mm dan frekuensi terbesar pada ikan jantan pada selang kelas rata-rata 220 mm (100 %) dan ikan betina pada selang kelas rata-rata 234 mm (100 %). Melalui histologi gonad ikan betina, pada TKG II terdapat sel oogonia dimana sel telur belum matang (perinucleolus) yaitu inti sel mulai membesar dan membran sel yang tebal. Pada TKG III, sel telur berkembang menjadi oocyte primer dan kemudian menjadi oocyte sekunder dimana sel telur telah matang (ripe eggs), butiran kuning telur telah terbentuk dan membran sel mulai menipis. Pada TKG IV, sel telur berkembang menjadi ootid, dimana terjadinya penyatuan butiran kuning telur yang menuju salah satu kutub anima (Fusion of yolk globule) dan terdapat membran sel yang menipis pada sel telur yang matang (Oolema of ripe eggs). Pada TKG V, sel telur berkembang menjadi ovum yang akan dikeluarkan pada saat pemijahan, mulai berkurangnya ootid dan terdapat folikel yang kosong. Sedangkan pada testes ikan jantan, TKG I ditunjukkan adanya sel spermatogonia yang berada di dalam kantung tubulus seminifer. Pada TKG I1 sel berkembang menjadi sel spermatogonia. Pada TKG III sel spermatogonia berkembang menjadi spermatocytes primer dimana terjadi pembelahan sel secara miosis (pembelahan pertama) dan kemudian berkembang menjadi spermatocytes sekunder dimana terjadi pembelahan sel yang kedua. Pada TKG IV sel spermatocytes berkembang menjadi sel spermatid, dan pada TKG V sel spermatid herkembang menjadi spermatozoa yang akan dikeluarkan pada saat pemijahan.
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