Komposisi Jenis Burung di Lahan Reklamasi Bekas Pertambangan Nikel, di Kabupaten Kolaka, Sulawesi Tenggara

Abstract

Pertambangan nikel merupakan kegiatan pertambangan yang dilakukan secara terbuka. Pertambangan secara terbuka memiliki risiko kerusakan lingkungan yang besar akibat pembersihan seluruh vegetasi di atas permukaan tanah dan pemindahan tanah pucuk (topsoil) ke stockpile. Kegiatan reklamasi pasca penambangan diharapkan mendukung keberhasilan pertumbuhan tanaman serta memudahkan akses pekerjaan selanjutnya ke seluruh areal reklamasi. Lahan reklamasi bekas pertambangan mengalami tahapan perubahan yang diharapkan menuju ke arah habitat alami. Burung sering dijadikan indikator perubahan habitat di lahan reklamasi karena berbagai karakteristiknya. Penelitian ini bertujuan untuk (1) mengidentifikasi jenis-jenis burung di lahan reklamasi tambang berdasarkan umur lahan reklamasi dan di hutan alami di lokasi pertambangan nikel; (2) membandingkan komunitas burung pada lahan reklamasi tambang berdasarkan umur lahan reklamasi dan hutan alami; (3) menduga faktor biotik dan abiotik yang mempengaruhi komunitas burung pada lahan reklamasi dan hutan alami di lokasi pertambangan nikel. Penelitian ini dilaksanakan pada lahan reklamasi tambang nikel tahun 2006 (umur 11 tahun), 2007 (10 tahun), 2009 (8 tahun), 2016 (1 tahun) dan hutan alami di sekitar lahan pertambangan di desa Huku-Huko, Kecamatan Pomala, Kabupaten Kolaka, Sulawesi Tenggara. Pengumpulan data burung dilakukan pada bulan Juli - Agustus 2017 dengan metode titik hitung. Pengumpulan data biotik dan abiotik yang dikumpulkan berupa fenologi tumbuhan, kelimpahan serangga, suhu, vegetasi dan jarak tegak lurus terdekat ke sungai, hutan primer serta pemukiman. Komposisi jenis burung dideskripsikan berdasarkan famili, endemisitas dan status konservasi serta jenis pakan utama atau guild. Analisis keanekaragaman burung menggunakan indeks Shannon, analisis kekayaan jenis burung menggunakan indeks Jacknife, analisis kesamaan komunitas menggunakan indeks kesamaan Sorensen. Pendugaan faktor lingkungan yang mempengaruhi kehadiran jenis burung pada lahan reklamasi tambang dihitung menggunakan analisis regresi berganda dan model linier. Total 41 jenis burung dari 23 famili dijumpai selama penelitian. Famili Accipitridae merupakan famili dengan anggota jenis terbanyak yaitu lima jenis. Satu jenis burung yang dijumpai merupakan jenis migran yaitu kirik-kirik australia (Merops ornatus). Terdapat 17 jenis endemik Sulawesi, dan satu jenis burung yang terancam punah menurut kategori IUCN, yaitu kangkareng Sulawesi (Penelopides exarhatus). Berdasarkan pakan utama (guild) 41 jenis burung dikelompokkan pada tujuh guild pakan. Kekayaan jenis dan keanekaragaman tertinggi ditemukan pada lahan reklamasi tahun 2006 (34 jenis, S=44, H’= 3,08), sedangkan kekayaan dan keanekaragaman burung terendah dijumpai pada lahan reklamasi tahun 2016 (16 jenis, S=21,45, H’=2,11). Analisis kesamaan komunitas burung menunjukkan bahwa lahan reklamasi tahun 2006 dan hutan alami memiliki nilai tertinggi (Cn = 0,79) dan yang paling rendah antara lahan reklamasi tahun 2016 dan hutan alami (Cn = 0,45). Berdasarkan persamaan hasil analisis regresi berganda ditemukan tiga peubah yang signifikan mempengaruhi kehadiran burung (Y) yaitu peubah jumlah individu serangga (X5), jumlah jenis pohon (X6) dan jarak tegak lurus terdekat ke sungai (X7), dengan persamaan model : Y = 4,567 + 0,149 (X5) + 0,303 (X6) + (- 1,586) (X7). Penelitian ini membuktikan bahwa kehadiran burung dipengaruhi oleh sumber pakan berupa serangga dan buah dan keberadaan air serta komposisi jenis burung mendekati kondisi alami dengan bertambahnya umur lahan reklamasi.

Nickel mining is one of open type mining that has a high risk on environment due to clearing of all aboveground vegetation, and transfer of topsoil to the stockpile. Post-mining reclamation activities are expected to support the success of plant growth and facilitate access to further activities in all reclamation areas. The mining reclaimed area undergoes stages of succession that is expected to finally resemble the natural habitat. Birds are often used as indicators of habitat change in reclaimed mine-land because of their various characteristics. The objectives of this study were (1) to identify bird species in mining reclamation land according to the age of reclamation, and natural forest in nickel mining area; (2) to compare bird communities in mining reclamation land according to the age of land reclamation and natural forest in nickel mining area; (3) to predict biotic and abiotic factors that affect bird communities on reclaimed mine-land and natural forests in nickel mining sites. This research was conducted on different ages of nickel mining reclamation land: 11 years (reclaimed in 2006), 10 years (reclaimed in 2007), 8 years (reclaimed in 2009), and 1 year (reclaimed in 2016) . Plots in natural forest around the mining area were also placed as comparison. All study are were located in Huku-Huko Village, Pomala District, Kolaka Regency, Southeast Sulawesi. Bird data collection was carried out in July - August 2017 using point count method. Biotic and abiotic data collected included plant phenology, insect abundance, temperature, vegetation and the closest perpendicular distance to rivers, primary forests and settlements. The composition of bird species is described based on family, endemicity and conservation status as well as feeding guild. Bird data were analyzed using Shannon index of diversity, Jacknife index, and Sorensen community similarity. Estimation of environmental factors that affect the presence of bird species on mine reclamation areas is calculated using multiple regression analysis and linear models. A total of 41 bird species from 23 families were found during the study. The Accipitridae family is the family with the highest number of species. One species of migratory bird was also fiund, i.e. Rainbow Bee-eater (Merops ornatus). There were 17 Sulawesi endemic species, and one of them is categorized as vulnerable buy IUCN, namely the Sulawesi hornbill (Rhabdotorrhinus exarhatus). Based on feeding guild the 41 species were classified into seven guilds. The highest species richness and diversity was found in year 2006 reclamation land (34 species, S = 44, H '= 3,08), while the lowest bird richness and diversity was found in 2016 reclaimed land(16 species, S = 21,45, H' = 2,11). The similarity analysis of bird communities showed that reclaimed land in 2006 and natural forest had the highest value (Cn = 0,79) while the lowest similarity was found between year 2016 reclaimed land and natural forest (Cn = 0,45). Based on the results of multiple regression analysis, it was found that 3 variables significantly affect the presence of birds (Y), namely, the insect abundance (X5), number of tree species (X6) and the closest perpendicular distance to the river (X7), with the model equation: Y = 4,567 + 0,149 (X5) + 0,303 (X6) + (- 1,586) (X7). This study showed that the presence of birds is influenced by food sources in the form of insects and fruit and the presence of water and the composition of bird species approaching natural conditions with increasing age of reclaimed land.