Keanekaragaman Semut (Hymenoptera:Formicidae) pada Sempadan Sungai di Beberapa Tipe Pengelolaan Lahan Perkebunan Kelapa Sawit di Riau

Abstract

Semut adalah kelompok serangga yang tersebar luas di dunia dengan total spesies terdeskripsi sekitar 16.000 spesies dan subspesies. Semut berperan penting dalam menjaga fungsi ekosistem dan sering digunakan sebagai bioindikator perubahan habitat. Pada lanskap perkebunan kelapa sawit, kondisi vegetasi sempadan sungai yang berbeda akibat variasi tipe pengelolaan lahan diduga memengaruhi struktur komunitas semut. Penelitian ini bertujuan mempelajari keanekaragaman dan komposisi komunitas semut pada tiga tipe pengelolaan lahan kelapa sawit, yaitu petani mandiri, plasma, perusahaan (restorasi), serta hutan sebagai habitat pembanding di sempadan sungai di Riau. Sebanyak 59 plot diamati, yaitu perkebunan petani mandiri (23 plot), plasma (21 plot), perusahaan (restorasi) (12 plot), dan hutan (3 plot). Semut dikoleksi menggunakan metode perangkap composite trap. Secara keseluruhan, 6.851 individu semut berhasil dikoleksi, terdiri atas 7 subfamili, 46 genus, dan 99 morfospesies. Kelimpahan individu tertinggi ditemukan pada petani mandiri, sedangkan kekayaan morfospesies tertinggi pada perusahaan (restorasi). Hutan menunjukkan kelimpahan dan kekayaan spesies paling rendah. Kelimpahan dan kekayaan spesies tertinggi adalah Pheidole plagiaria dan Anoplolepis gracilipes. Tipe pengelolaan lahan signifikan memengaruhi kelimpahan (F3,2128 = 5,74, p < 0,001), kekayaan spesies (F3,39 = 24.03, p<0.001) dan komposisi semut (ANOSIM, Sign = 0,001; stress = 0,17). Analisis NMDS menunjukkan komposisi komunitas semut pada ketiga tipe perkebunan memiliki kemiripan tinggi, sedangkan komunitas semut di hutan berbeda jelas, didominasi Diacamma rugosum. Subfamili Myrmicinae dan sepuluh morfospesies ditemukan banyak pada ketiga tipe pengelolaan lahan dan hutan. Berdasarkan hasil analisis faktor lingkungan, suhu merupakan satu-satunya variabel yang berpengaruh nyata terhadap komposisi komunitas semut. Hasil ini mendukung pengelolaan sempadan sungai berkelanjutan dalam lanskap perkebunan kelapa sawit.

Ants are a group of insects found throughout the world, with a total of approximately 16,000 described species and subspecies. Ants play an important role in maintaining ecosystem function and are often used as bioindicators of habitat change. In oil palm plantation landscapes, differences in riparian vegetation conditions resulting from variations in land management practices are thought to influence ant community structure. This study aims to investigate the diversity and composition of ant communities across three types of oil palm land management types independent, plasma plantations, and company plantations (restoration) as well as forest as a reference habitat along riparian in Riau. A total of 59 plots were observed, including independent plantations (23 plots), plasma plantation (21 plots), company (restoration) plantations (12 plots), and forest (3 plots). Ants were collected using composite trap method. Overall, 6,851 ant individuals were collected, comprising 7 subfamilies, 46 genera, and 99 morphospecies were collected. The highest abundance of individual was found in independent, while the highest morphospecies richness was found in company (restoration) plantations. Forest exhibited the lowest species abundance and richness. The highest species abundance and richness were observed for Pheidole plagiaria and Anoplolepis gracilipes. Land management type significantly influenced abundance (F3,2128 = 5,74, p < 0,001), species richness (F3,39 = 24.03, p < 0.001), and ant community composition (ANOSISM, Sign = 0,001; stress = 0,17. NMDS analysis showed that ant community composition across the three plantation types exhibited high similarity, whereas the ant community in the forest was distinctly different, dominated by Diacamma rugosum. The subfamily Myrmicinae and ten morphospecies were commonly found across all three land management types and the forest. Based on the results of the environmental factor analysis, temperature was the only variable that had a significant effect on ant community composition. These results support sustainable management of riparian within oil palm plantation landscapes.