Pengaruh Jenis dan Kerapatan Vegetasi Mangrove terhadap Kandungan Cd dan Cr Sedimen di Wilayah Pesisir Semarang dan Demak

Abstract

ABSTRACT The role of mangrove vegetation as the filter of pollutant materials needs further study, especially concerning the effort of managing coastal ecosystem pollution. This research aimed to study the effect of mangrove vegetation species and abundance to the sediment Cd and Cr concentration in Semarang and Demak coastal area. Data collection was conducted through transect method including 8 stations and 3 transect on each station. Vegetation data was grouped to its species and stages. Heavy metal sample were collected from the same transect, which was the sediment sand. Data analysis was conducted with regression and modeling with POwerSIM. Field observation showed that mangrove vegetation in Semarang and Demak was dominated by Avicennia and Rhizophora. Abundance of Avicennia tree was ranged from 600 – 4.700 stands/ha, while the sapling ranged from 1.867 – 18.000 stands/ha and 16.667 – 150.000 stands/ha for seedling stage. Rhizophora abundance was ranged from 1.422 – 6.517 stands/ha, while sapling abundance was ranged from 1.600 – 13.822 stands/ha and seedling abundance was ranged from 22.000 – 305.556 stands/ha. The concentration of Cd found in sampling transect ranged from 2.3 – 33 mg/kg while Cr was ranged from 1.1 – 7.4 mg/kg. Data analysis showed that mangrove vegetation role the concentration of Cd and Cr. The Cr was effected by Rhizophora tree, sapling and seedling. While the concentration of Cd was effected by the abundance of Rhizophora tree and Avicennia seedling. Rhizophora tree and seedling had possitive effect on the Cr concentration, while Rhizophora sapling had negative effect. While Rhizophora tree had polinomial effect on Cd concentration while Avicennia seedling had possitive effect. Keywords: mangrove, sediment, Cd concentration, Cr concentration