Rehabilitasi Kawasan Mangrove di Hutan Lindung Muara Sekampung, Kabupaten Lampung Timur, Sumatera

Abstract

Ekosistem mangrove memiliki fungsi ekologis, fisik, dan sosial ekonomi yang penting dalam menjaga stabilitas wilayah pesisir. Namun, kawasan mangrove di Hutan Lindung Muara Sekampung, Kabupaten Lampung Timur, mengalami degradasi akibat sedimentasi, perubahan hidrologi, dan aktivitas antropogenik yang menyebabkan menurunnya kualitas lingkungan serta kematian vegetasi mangrove. Kondisi tersebut menyebabkan berkurangnya fungsi ekosistem mangrove sebagai pelindung pantai, habitat biota, dan penyangga kehidupan masyarakat pesisir. Penelitian ini bertujuan untuk menganalisis luas areal yang berpotensi direhabilitasi, kondisi biofisik lingkungan, kesesuaian spesies dan desain penanaman mangrove beserta estimasi biaya rehabilitasi, serta stakeholder yang berperan dalam mendukung rehabilitasi mangrove di Hutan Lindung Muara Sekampung. Penelitian dilaksanakan pada bulan Maret hingga Mei 2025 di Hutan Lindung Muara Sekampung (Register 15), Kecamatan Pasir Sakti, Kabupaten Lampung Timur, Provinsi Lampung. Penentuan luas areal rehabilitasi dilakukan menggunakan analisis citra satelit berbasis Normalized Difference Vegetation Index (NDVI) yang dipadukan dengan verifikasi lapangan. Analisis biofisik meliputi vegetasi, fauna yang berpotensi menjadi hama, sifat fisik dan kimia tanah, kualitas air, serta parameter oseanografi berupa pasang surut, kedalaman genangan, dan kecepatan arus. Penentuan spesies mangrove dan desain penanaman dilakukan menggunakan pendekatan species–site matching berdasarkan kesesuaian kondisi lingkungan. Analisis biaya dilakukan terhadap kegiatan persemaian, pengadaan bibit, dan penanaman awal mangrove. Analisis stakeholder dilakukan menggunakan metode Matrix of Alliances and Conflicts: Tactics, Objectives and Recommendations (MACTOR). Hasil penelitian menunjukkan bahwa kawasan Hutan Lindung Muara Sekampung memiliki luas area potensial rehabilitasi sebesar 474,47 ha yang didominasi oleh kelas vegetasi sangat rendah hingga tidak bervegetasi. Berdasarkan hasil verifikasi lapangan, areal rehabilitasi yang ditetapkan dalam penelitian ini seluas ±20 ha pada kawasan berlumpur yang masih dipengaruhi pasang surut dan memiliki sisa tegakan mangrove mati, terutama dari jenis Avicennia sp. Hasil analisis vegetasi menunjukkan bahwa pada seluruh plot pengamatan tidak ditemukan vegetasi mangrove hidup, baik pada tingkat semai, pancang, maupun pohon. Kondisi kualitas air menunjukkan salinitas rendah dengan rata-rata 1,63 ppt dan pH relatif netral hingga agak basa. Tanah didominasi oleh tekstur liat dengan rata-rata kandungan liat sebesar 53,2%, salinitas tanah kategori mesohalin, serta kandungan bahan organik dan unsur hara yang relatif tinggi. Hasil pengukuran oseanografi menunjukkan tipe pasang surut harian tunggal dengan kedalaman genangan berkisar 40–98 cm dan kecepatan arus 0,18–0,53 m/s. Hasil analisis species–site matching menunjukkan bahwa jenis mangrove yang sesuai untuk ditanam meliputi Rhizophora mucronata, Rhizophora apiculata, Rhizophora stylosa, Avicennia marina, Avicennia alba, Sonneratia caseolaris, dan Sonneratia alba. Desain penanaman yang direncanakan terdiri atas cluster planting, line cluster planting, dan quadrat planting dengan variasi jarak tanam sesuai kondisi mikrohabitat. Total kebutuhan bibit untuk rehabilitasi seluas 20 ha mencapai 125.269 batang. Estimasi biaya rehabilitasi tahap awal melalui skenario persemaian mandiri sebesar Rp401.564.900 atau sekitar Rp20.078.245/ha, sedangkan melalui skenario pengadaan bibit sebesar Rp616.326.000 atau sekitar Rp30.816.300/ha. Setelah dinormalisasi berdasarkan kepadatan standar 5.000 batang/ha, biaya rehabilitasi menjadi Rp16.025.000/ha pada skenario persemaian mandiri dan Rp24.600.000/ha pada skenario pengadaan bibit. Kedua nilai tersebut berada di bawah standar pembiayaan pemerintah, yang menunjukkan bahwa persemaian mandiri berbasis masyarakat merupakan alternatif penyediaan bibit yang lebih ekonomis. Hasil analisis stakeholder menunjukkan bahwa terdapat 13 aktor utama yang terlibat dalam rehabilitasi mangrove. Kelompok Tani Hutan Mutiara Hijau 1 dan BPDAS Way Seputih Way Sekampung merupakan aktor dengan tingkat pengaruh tertinggi dalam sistem rehabilitasi mangrove. Sebagian besar aktor memiliki posisi yang mendukung rehabilitasi mangrove dengan tingkat konvergensi antaraktor yang tinggi. Hasil penelitian ini menunjukkan bahwa rehabilitasi mangrove di Hutan Lindung Muara Sekampung memiliki dukungan biofisik dan kelembagaan yang cukup baik untuk dilaksanakan secara kolaboratif dan berkelanjutan.

Mangrove ecosystems play important ecological, physical, and socio-economic roles in maintaining coastal stability. However, mangrove areas in the Muara Sekampung Protected Forest, East Lampung Regency, have experienced degradation caused by sedimentation, hydrological changes, and anthropogenic activities, resulting in declining environmental quality and mangrove vegetation mortality. These conditions have reduced the ecological functions of mangroves as coastal protection, habitat for aquatic organisms, and environmental support systems for coastal communities. This study aimed to analyze the potential rehabilitation area, bio-physical environmental conditions, suitability of mangrove species and planting designs along with rehabilitation cost estimation, and stakeholders involved in supporting mangrove rehabilitation in the Muara Sekampung Protected Forest. The study was conducted from March to May 2025 in the Muara Sekampung Protected Forest (Register 15), Pasir Sakti District, East Lampung Regency, Lampung Province. Determination of rehabilitation areas was carried out using satellite imagery analysis based on the Normalized Difference Vegetation Index (NDVI) combined with field verification. Bio-physical analyses included vegetation, fauna potentially acting as mangrove pests, soil physical and chemical properties, water quality, and oceanographic parameters including tides, inundation depth, and current velocity. Determination of mangrove species and planting design was conducted using a species–site matching approach based on environmental suitability. Cost analysis covered nursery activities, seedling procurement, and initial mangrove planting. Stakeholder analysis was conducted using the Matrix of Alliances and Conflicts: Tactics, Objectives and Recommendations (MACTOR) method. The results showed that the Muara Sekampung Protected Forest has a potential rehabilitation area of 474.47 ha dominated by very low vegetation to non-vegetated classes. Based on field verification, the rehabilitation area selected in this study covered approximately 20 ha of muddy substrate still influenced by tidal inundation and containing remnants of dead mangrove stands, particularly Avicennia sp. Vegetation analysis indicated that no living mangrove vegetation was found in all observation plots at seedling, sapling, or tree levels. Water quality analysis showed low salinity with an average value of 1.63 ppt and neutral to slightly alkaline pH conditions. Soil characteristics were dominated by clay texture with an average clay content of 53.2%, mesohaline soil salinity, and relatively high organic matter and nutrient contents. Oceanographic analysis indicated a diurnal tidal type with inundation depths ranging from 40–98 cm and current velocities ranging from 0.18–0.53 m/s. The species–site matching analysis showed that suitable mangrove species for rehabilitation included Rhizophora mucronata, Rhizophora apiculata, Rhizophora stylosa, Avicennia marina, Avicennia alba, Sonneratia caseolaris, and Sonneratia alba. The proposed planting designs consisted of cluster planting, line cluster planting, and quadrat planting with various spacing arrangements adjusted to microhabitat conditions. The total seedling requirement for the 20 ha rehabilitation area was 125,269 seedlings. The estimated initial rehabilitation cost under the independent nursery scenario was Rp401,564,900, or approximately Rp20,078,245/ha, while the seedling procurement scenario required Rp616,326,000, or approximately Rp30,816,300/ha. After normalization based on the standard density of 5,000 seedlings/ha, the rehabilitation costs were Rp16,025,000/ha for the independent nursery scenario and Rp24,600,000/ha for the seedling procurement scenario. Both costs were lower than the government financing standard, indicating that a community-based independent nursery is a more economical alternative for seedling provision. Stakeholder analysis identified 13 main actors involved in mangrove rehabilitation. The Mutiara Hijau 1 Forest Farmer Group and the Way Seputih–Way Sekampung Watershed Management Agency were identified as the most influential actors within the mangrove rehabilitation system. Most stakeholders showed supportive positions toward mangrove rehabilitation with a high level of convergence among actors. The results indicate that mangrove rehabilitation in the Muara Sekampung Protected Forest has sufficient bio-physical and institutional support to be implemented collaboratively and sustainably.