Calon Promotor Program Beasiswa Program Doktoral Padjadjaran Tahun 2026

 

Nama Lengkap : Prof. Alexander M. A. Khan, S.Pi., M.Si., Ph.D.

E-mail : [email protected]

Bidang Keahlian : Konservasi dan Pengelolaan Perikanan

Prodi S3 Calon Mahasiswa: Perikanan dan Kelautan Berkelanjutan

Judul Penelitian yang Ditawarkan:

Pengembangan Model Carbon Instability Index (CII) Untuk Evaluasi  Stabilitas Karbon Sedimen Pesisir Tropis Dan Implikasinya Terhadap Mitigasi Perubahan Iklim

Development of a Carbon Instability Index (CII) Model for the Evaluation of Tropical Coastal Sediment Carbon Stability and Its Implications for Climate Change Mitigation

 

Abstrak:

Ekosistem pesisir tropis seperti mangrove dan padang lamun berperan penting dalam siklus karbon global melalui kemampuannya menyerap dan menyimpan karbon organik dalam sedimen dalam jangka waktu panjang. Namun, stabilitas karbon sedimen tidak selalu terjamin karena karbon organik terdiri atas fraksi dengan tingkat reaktivitas berbeda. Fraksi karbon labil rentan mengalami mineralisasi dan oksidasi akibat gangguan lingkungan, seperti perubahan tata guna lahan, aktivitas pelabuhan, pengerukan, serta fluktuasi kondisi redoks yang dipicu oleh dinamika pasang surut. Sebagian besar penelitian sebelumnya berfokus pada Total Organic Carbon (TOC), sehingga belum sepenuhnya mampu menjelaskan stabilitas karbon dan potensi remobilisasinya. Teluk Riau sebagai sistem pesisir tropis semi-tertutup memiliki kompleksitas ekologi tinggi dan tekanan antropogenik yang intens. Interaksi antara karakteristik sedimen, kualitas bahan organik, dan dinamika lingkungan di wilayah ini berpotensi memengaruhi stabilitas karbon sedimen, namun kajian komprehensif terkait kerentanannya masih terbatas. Penelitian ini bertujuan mengembangkan Carbon Instability Index (CII) sebagai indikator komposit untuk menilai kerentanan karbon sedimen. Secara khusus, penelitian ini bertujuan untuk: (i) menganalisis karakteristik fraksi karbon organik sedimen; (ii) mengembangkan dan memvalidasi model CII berbasis integrasi parameter biogeokimia dan lingkungan; serta (iii) mengevaluasi implikasinya terhadap mitigasi perubahan iklim. Penelitian menggunakan pendekatan terintegrasi yang mengombinasikan pengambilan sampel lapangan, analisis biogeokimia sedimen, dan pemodelan statistik multivariat. Sampel sedimen dikumpulkan dari 12 stasiun yang mewakili variasi habitat dan tekanan antropogenik, dengan fokus pada lapisan permukaan (0–10 cm). Analisis meliputi pengukuran TOC, pemisahan fraksi karbon labil dan refrakter melalui oksidasi kimia sekuensial, serta analisis karbon organik terikat besi (Fe-bound OC). Parameter fisik sedimen dan kondisi lingkungan juga dianalisis. Data diolah menggunakan PCA, RDA, analisis korelasi, dan regresi untuk mengidentifikasi faktor utama yang memengaruhi stabilitas karbon. Luaran penelitian meliputi pengembangan model CII, publikasi ilmiah, dan rekomendasi pengelolaan berbasis blue carbon. Penelitian ini berada pada Tingkat Kesiapterapan Teknologi (TKT) 2–3 dan diharapkan berkontribusi dalam pengembangan pendekatan kuantitatif untuk mengevaluasi stabilitas karbon sedimen serta mendukung strategi mitigasi perubahan iklim pada ekosistem pesisir tropis.

 

Abstract:

Tropical coastal ecosystems such as mangroves and seagrass beds play a critical role in the global carbon cycle due to their capacity to sequester and store organic carbon in sediments over long timescales. However, the stability of sedimentary carbon is not guaranteed, as organic carbon consists of fractions with varying reactivity. Labile fractions are particularly susceptible to mineralization and oxidation under environmental disturbances, including land-use changes, dredging, port activities, and redox fluctuations driven by tidal dynamics. Most previous studies have focused primarily on Total Organic Carbon (TOC), which limits the understanding of carbon stability and its potential remobilization. Riau Bay, a semi-enclosed tropical coastal system, exhibits high ecological complexity and is subjected to significant anthropogenic pressures. The interaction between sediment characteristics, organic matter quality, and environmental variability is likely to influence sediment carbon stability in this region. However, comprehensive assessments of sediment carbon vulnerability in tropical coastal ecosystems remain limited. This study aims to develop a Carbon Instability Index (CII) as a composite indicator to quantify sediment carbon vulnerability. Specifically, the objectives are to: (i) characterize sediment organic carbon fractions; (ii) develop and validate a CII model integrating biogeochemical and environmental parameters; and (iii) evaluate implications for climate change mitigation. The novelty lies in integrating organic carbon fractions, organo-mineral associations, sediment properties, and environmental dynamics into a unified predictive framework. A multidisciplinary approach was employed, combining field sampling, laboratory-based biogeochemical analyses, and multivariate statistical modeling. Sediment samples were collected from 12 stations representing different habitat types and anthropogenic gradients, using sediment corers to a depth of 30 cm, with analysis focused on the upper 0–10 cm layer. Laboratory analyses included TOC measurement, sequential chemical oxidation to separate labile and refractory fractions, and Fe-bound organic carbon extraction using the DCB method. Sediment physical properties (grain size and bulk density) and environmental parameters (temperature, salinity, pH, dissolved oxygen, and hydrodynamics) were also measured. Statistical analyses included PCA, RDA, correlation, and regression to identify key drivers of carbon stability. The expected outputs include a validated CII model, scientific publications, and policy-relevant recommendations for blue carbon management. Positioned at Technology Readiness Level (TRL) 2–3, this study contributes to advancing quantitative approaches for assessing sediment carbon stability and supports climate mitigation strategies in tropical coastal ecosystems.