Struktur dan Komposisi Vegetasi Lahan Pascatambang Emas di Tapanuli Selatan, Sumatera Utara

Abstract

Metode tambang terbuka (open pit mining) pada tambang emas berdampak signifikan terhadap lingkungan. Penelitian ini bertujuan menganalisis struktur dan komposisi vegetasi pada area revegetasi lahan pascatambang emas di Tapanuli Selatan, Sumatera Utara. Analisis struktur dan komposisi vegetasi diamati pada usia revegetasi yang berbeda (2, 3, 7, 8, 9, 10 tahun dan hutan alam sebagai pembanding). Pengambilan data area revegetasi dilakukan dengan metode kuadrat dan pengambilan data di hutan alam menggunakan metode garis berpetak. Sebanyak 22 famili yang tersebar di antara 37 jenis semai dan tumbuhan bawah, 19 jenis pancang, 14 jenis tiang, dan 7 jenis pohon ditemukan pada area revegetasi. Struktur tegakan pada area berusia 10, 9, dan 8 tahun, serta hutan alam memiliki bentuk kurva J terbalik. Hasil perhitungan indeks kekayaan jenis (R) dan indeks keragaman jenis (H') termasuk rendah hingga sedang, dan indeks kemerataan (E) termasuk rendah hingga tinggi. Tanah menunjukkan tekstur lempung hingga liat, dengan kategori pH asam hingga agak asam, dan kandungan bahan organik yang rendah. Seiring bertambahnya usia revegetasi, terjadi peningkatan kadar C-organik dan N-total pada tanah.

The open-pit mining method in gold mines has significant impact on the environment. This study aimed to analyze the structure and composition of vegetation in revegetation area of post-gold mining land in South Tapanuli, North Sumatera. In this study, vegetation structure and composition analysis were observed in different revegetation years (2, 3, 7, 8, 9, 10 years and natural forest as control area). Data collection in revegetation areas and natural forests were studied using quadrat method and strip method, respectively. A total of 22 families distributed among 37 species of seedlings and undergrowth, 19 species of saplings, 14 species of poles, and 7 species of trees were found in revegetation areas. The stand structure in areas aged 10, 9, and 8 years, as well as in natural forests, has an inverted J-shaped curve. The species richness index (R) and species diversity index (H') were low to moderate categories, and the evenness index (E) was low to high. The soils exhibited a loam to clay textures, with a slightly acidic to acidic pH, and limited organic matter. It was discovered that total organic C and N levels increased with the age of revegetation.