Hubungan Sifat Kimia Tanah dan Keberadaan Fauna Tanah di Lahan Rehabilitasi, Kawasan Geothermal, Darajat, Garut, Jawa Barat

Abstract

Star Energy Geothermal Darajat II (SEGD II) melaksanakan rehabilitasi pada lahan yang terdegradasi akibat longsor di kawasan izin usahanya. Keberhasilan rehabilitasi dapat dinilai melalui kandungan sifat kimia tanah dan kehadiran fauna tanah. Penelitian ini bertujuan untuk mengidentifikasi sifat kimia tanah, menganalisis komunitas fauna tanah, dan mengkaji hubungannya di lahan rehabilitasi dan hutan alam sebagai pembanding. Sampel diambil dari lima plot (20 m × 100 m) per lokasi pada kedalaman 0–20 cm. Fauna tanah dikumpulkan dengan metode hand capture dan diekstraksi dengan corong Barlese-Tullgren, dan hubungan antar variabel diuji dengan korelasi Spearman. Tanah di kedua lokasi bersifat masam (pH = 5,22-5,46), C-organik tinggi, dan tidak terindikasi tercemar logam berat. Teridentifikasi 14 ordo dan 20 famili fauna tanah dengan indeks keanekaragaman Shannon-Wiener (H') berkategori sedang (H’ = 1,69), indeks kekayaan jenis (DMg) berkategori rendah (DMg = 2,34), dan indeks kemerataan jenis (E) berkategori rendah (E = 0,263). pH dan C-organik berkorelasi kuat terhadap DMg (r = 0,90–1,00), namun lemah terhadap H' (r = 0,1–0,3) dan E (r = 0,1–0,2), mencerminkan komunitas masih dalam suksesi awal.

Star Energy Geothermal Darajat II (SEGD II) is carrying out rehabilitation of land degraded by landslides within its business license area. The success of the rehabilitation can be assessed through soil chemical properties and the presence of soil fauna. This study aims to identify soil chemical properties, analyze soil fauna communities, and examine their relationships in the rehabilitated area and in natural forest as a control. Samples were collected from five plots (20 m × 100 m) per location at a depth of 0–20 cm. Soil fauna were collected using the hand-capture method and extracted using a Barlese-Tullgren funnel, and relationships between variables were tested using Spearman’s correlation. The soil at both sites was acidic (pH = 5,22–5,46), had high organic carbon content, and showed no indication of heavy metal contamination. Fourteen orders and 20 families of soil fauna were identified, with a Shannon-Wiener diversity index (H’) in the moderate category (H’ = 1.69), a low species richness index (DMg) (DMg = 2,34), and a low species evenness index (E) (E = 0,263). pH and organic carbon showed a strong correlation with DMg (r = 0,90–1,00), but a weak correlation with H’ (r = 0,1–0,3) and E (r = 0,1–0,2), reflecting that the community is still in the early stages of succession.