Suksesi vegetasi alami pada bekas tambang timah pulau Bangka

TJHIAW, Guat, Dr. Tjut Sugandawaty Djohan, M.Sc

2008 | Tesis | S2 Biologi

Penelitian ini mempelajari suksesi vegetasi alami berbagai umur sere di Pulau Bangka. Komunitas sere tersebut terdiri dari overburden 2 bulan, overburden ± 1 tahun, subsoil ± 1 tahun, tailing ± 3 tahun, overburden < 10 tahun, tailing < 10 tahun, overburden > 20 tahun, dan tailing > 20 tahun. Hasil ini dibandingkan dengan hutan alam yang belum ditambang. Metode yang digunakan adalah kuadrat plot dengan ukuran 2mx4m, 5mx5m, dan 10mx20m yang disesuaikan dengan persebaran vegetasi di lokasi dengan ulangan berkisar 3-15 kali. Hasil penelitian menunjukkan bahwa growthform komunitas sere overburden lebih banyak dibandingkan komunitas sere tailing. Vegetasi yang dominan pada sere awal adalah rumput Ischaemum muticum dan Imperata cylindrica. Pada sere selanjutnya didominasi oleh semak Melastoma malabathricum. Selain itu juga ditemukan familia Leguminosae, dan Nepenthes sp sebagai indikator miskinnya unsur hara. Sedangkan seedling pohon tersebar jarang terdiri dari Macaranga sp, Malaleuca leucadendron, Schima wallichii, Vitex pubescens, Anacardium occidentale, dan Alstonia schoolaris. Ternyata kehadiran vegetasi merespon pada kandungan hara, terutama bahan organik dan nitrat. Pada komunitas sere overburden < 10 tahun dan > 20 tahun, serta tailing > 20 tahun ditemukan introduce species, yaitu Acacia spp. Adanya pohon Dyera costulata pada hutan alam sebagai indikasi hutan rawa gambut. Sebaliknya pada hutan alam dengan tekstur tanahnya mirip dengan tekstur tanah pada semua komunitas sere kajian bekas tambang timah didominasi oleh pohon dan sapling Eugenia palembanica serta seedling Eugenia longiflora.

Succession of natural vegetation at various seral-stages were studied in ex tin-mining Bangka Island. These seral stages were 2 months of overburden, 1 year of tailing, 1 year of subsoil, 3 years of tailing, 10 years of overburden, 10 years of tailing, 20 years of overburden, and 20 years of tailing and natural forest as a comparison. Data were collected based on various growthforms using various quadrate plots of 2mx4m, 5mx5m, and 10mx20m and had replicate of 3 to 15 plots. The results showed that the number of growthforms of sere was found more at location of overburden more than the tailing. The dominant plants at pioneer stage were Ischaemum muticum and Imperata cylindrica. The next seral stage was dominated by shrubs of Melastoma malabathricum. We also found Leguminosae and Nepenthes sp, which indicated that the location of post mining were poor in nutrients. The tree seedlings were dispersed rarely, and consisted of Macaranga sp, Malaleuca leucadendron, Schima wallichii, Vitex pubescens, Anacardium occidentale, and Alstonia schoolaris. The present of vegetation during the seral stages were as a respon to the nutrient content especially organic matter and nitrate. On location 10 years and 20 years of overburden, and also 20 years of tailing were found introduce species of Acacia spp. Trees of Dyera costulata were found on natural forest, which were indicated of peat swamp forest. The natural forest were dominated by trees and saplings of Eugenia palembanica and seedlings of Eugenia longiflora, but their soil textures were similar with all locations of post tin-mining sere.

Kata Kunci : Suksesi alamai,Timah,tambang,Vegetasi,Overburden,Tailing,Unsur hara, natural succession, tin mining, vegetation, overburden, tailing, nutrient content