Judul: DETERMINING REHABILITATION STRATEGY FOR MANGROVE ECOSYSTEM: CASE OF TANJUNG VILLAGE, SARONGGI DISTRICT, SUMENEP REGENCY, JAWA TIMUR PROVINCE, INDONESIA
Abstrak: Ekosistem mangrove beberapa tahun terakhir mengalami ancaman degradasi yang disebabkan tingginya aktivitas manusia dalam mengeksploitasi wilayah pesisir. Penelitian dilaksanakan pada bulan Juli 2022 sampai Februari 2023, di Desa Tanjung, Kecamatan Saronggi, Sumenep, Jawa Timur. Tujuan penelitian ini adalah merumuskan strategi rehabilitasi mangrove yang holistik dengan pendekatan ekologis dan sosial, guna mendukung pelestarian keseimbangan ekosistem di Desa Tanjung sebagai desa pesisir. Indeks Kesehatan Mangrove dan Indeks Kualitas Lingkungan mangrove digunakan untuk menilai kerusakan ekosistem mangrove. Masyarakat menyebutkan bahwa upaya dalam menjaga keberlangsungan ekosistem mangrove yang sudah ada masih terus dilakukan hingga saat ini. Strategi yang benar berdasarkan matriks rehabilitasi yang dihasilkan adalah replantasi dan perbaikan lingkungan. Strategi replantasi harus mempertimbangkan penanaman berdasarkan zonasi dan jenis-jenis mangrove yang ditanam, sedangkan strategi perbaikan lingkungan berfokus pada peremajaan terhadap aspek lingkungan., Mangrove ecosystems in recent years have been under threat of degradation due to high human activity in exploiting coastal areas. The research was conducted from July 2022 to February 2023, in Tanjung Village, Saronggi District, Sumenep, East Java. The purpose of this research is to formulate a holistic mangrove rehabilitation strategy with ecological and social approaches, to support the preservation of ecosystem balance in Tanjung Village as a coastal village. The Mangrove Health Index and the Mangrove Environmental Quality Index were used to assess damage to the mangrove ecosystem. The community mentioned that efforts to maintain the sustainability of the existing mangrove ecosystem are still being carried out today. The correct strategy based on the resulting rehabilitation matrix is replantation and environmental improvement. The replantation strategy should consider planting based on zoning and the types of mangroves planted, while the environmental improvement strategy focuses on rejuvenating the environmental aspects.
Keyword: ekologi mangrove, kesehatan mangrove, kualitas lingkungan, strategi pengelolaan, mangrove ecology, mangrove health, environmental quality, management strategies

Judul: Analysis of Mangrove Damage and Rehabilitation Steps in the Angke Kapuk Protected Forest, North Jakarta
Abstrak: Ekosistem mangrove merupakan salah satu habitat alami pada kawasan pesisir yang sangat rentan terhadap ancaman alam baik dari darat maupun laut. Selain disebabkan oleh alam, ancaman terhadap ekosistem mangrove juga dapat disebabkan oleh kegiatan manusia. Penelitian ini bertujuan untuk menganalisis tingkat kerusakan mangrove dan potensi rehabilitasi mangrove di Hutan Lindung Angke Kapuk, Jakarta Utara. Penelitian ini dilaksanakan pada bulan Desember 2021 hingga Januari 2022 dengan lokasi penelitian terdiri dari tiga stasiun yang meliputi tiga tipe yaitu teluk, muara sungai, dan pantai reklamasi. Kerapatan dan penutupan mangrove di Angke Kapuk tergolong dalam kriteria rendah, kecuali stasiun 1 yang memiliki kerapatan sangat tinggi dan penutupan mangrove dalam kriteria rendah. Kondisi ini mengakibatkan nilai indeks kesehatan mangrove menjadi sedang pada stasiun 1, sedangkan stasiun 2 dan 3 tergolong kategori rendah. Indeks kualitas lingkungan pada ketiga stasiun tergolong kedalam kategori tinggi. Berdasarkan nilai kedua indeks tersebut, tingkat kerusakan pertumbuhan mangrove tergolong tinggi dan kerusakan lingkungan mangrove tergolong rendah dan diketahui matriks rehabilitasi mangrove dengan strategi replantasi. Strategi replantasi tersebut mempertimbangkan zonasi dalam penentuan jenis mangrove yang ditanam., Mangrove , one of the natural ecosystems in coastal areas is very vulnerable to n threats both from land and sea. Besides being caused by nature, threats to mangrove ecosystems can also be caused by human activities. This study aims to analyze the level of damage to mangroves and the potential for mangrove rehabilitation in the Angke Kapuk Protection Forest, North Jakarta. This research was carried out from December 2021 to January 2022 with research locations consisted of three stations covering three types, namely bays, river mouths, and reclamation beaches. The density and cover of mangroves in Angke Kapuk are classified as low criteria, except for station 1 which has a very high density and mangrove cover is in the low criteria. This condition causes the mangrove health index value to be moderate at station 1, while stations 2 and 3 are in the low category. The environmental quality index at the three stations belongs to the high category. Based on the values of these two indices, the level of damage to mangrove growth is classified as high and environmental damage to mangroves is classified as low and it is known that the mangrove rehabilitation matrix with a replantation strategy. The replantation strategy considers zoning in determining the type of mangrove to be planted
Keyword: kesehatan mangrove, kualitas lingkungan, mangrove, rehabilitasi, environmental quality, mangrove health, rehabilitation, mangroves

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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