Rainforest conversion to smallholder cash crops leads to varying declines of beetles (Coleoptera) on Sumatra. (14th October 2022)

• Record Type: Journal Article
• Authors: Kasmiatun, ; Hartke, Tamara R.; Buchori, Damayanti; Hidayat, Purnama; Siddikah, Fatimah; Amrulloh, Rosyid; Hiola, Muhammad Syaifullah; Najmi, Lailatun; Noerdjito, Woro A.; Scheu, Stefan; Drescher, Jochen
• Is Part Of: Biotropica. Volume 55:Number 1(2023)
• Page Start: 119
• Page End: 131
• Publication Date: 2022-10-14
• Subjects: agroforestry -- beta diversity partitioning -- jungle rubber -- latent variable model -- monoculture -- oil palm -- rainforest -- rubber -- smallholder -- Southeast Asia -- weevils; Biotic communities -- Tropics -- Periodicals; Applied ecology -- Tropics -- Periodicals; Biology -- Tropics -- Periodicals; 577.80913
• DOI: 10.1111/btp.13165
• Languages: English
• ISSNs: 0006-3606

Abstract

Abstract: Southeast Asian arthropod biodiversity is in rapid decline, but the variability of responses within taxa has received little attention. Using canopy fogging, we collected ~50, 000 beetles (Coleoptera) in (1) lowland rainforest, (2) jungle rubber (rubber agroforest), and smallholder monoculture plantations of (3) rubber and (4) oil palm in Sumatra, across two landscapes and seasons. On average, beetle abundance was more than 50%, and biomass over 75%, lower in rubber and oil palm plantations than in rainforest and jungle rubber. This pattern was influenced by landscape and season. Abundance and biomass declines were similar in Chrysomelidae, Elateridae, and Staphylinidae, but differed in Curculionidae, which were most abundant in oil palm due to the introduced oil palm pollinator Elaeidobius kamerunicus . Across beetle families, species richness in monocultures was reduced by at least 70% compared to rainforest, with beetle richness in jungle rubber being similar to rainforest. Community composition in oil palm plantations differed markedly from the other land‐use systems for Chrysomelidae and Curculionidae, but less for Elateridae and Staphylinidae. Turnover contributed more to overall beta diversity than nestedness for all families and land‐use systems. Likely undersampling of the beetle community in rainforest suggests that declines of beetle density and diversity are much more severe than reported here, especially for beetle families with many concealed species, such as Staphylinidae. This study provides first evidence that negative responses of beetles to tropical land‐use change vary among families, and is the first report of its kind from heavily understudied Sumatra. Abstract in Indonesia is available with online material. Abstract : This study compared canopy beetle density and diversity between lowland rainforest and the three main cash crop agriculture systems in Sumatra, Indonesia: jungle rubber agroforest, and monoculture plantations of rubber and oil palm. Focusing on the four beetle families Chrysomelidae, Curculionidae, Elateridae and Staphylinidae, we demonstrate severe population and richness declines, as well as altered community composition and beta diversity patterns after rainforest conversion to cash crop agriculture in Southeast Asia. RESUMEN: Penurunan keanekaragaman artropoda di Asia Tenggara terjadi secara cepat, namun keragaman respon dari berbagai taksa belum banyak mendapat perhatian. Dengan metode pengasapan kanopi, kami mengumpulkan ~50.000 individu kumbang (Coleoptera) di (1) hutan hujan dataran rendah, (2) hutan karet (agroforesti karet), serta perkebunan (3) karet dan (4) kelapa sawit, pada dua lanskap dan musim berbeda di Sumatra, Indonesia. Hasil penelitian menunjukkan bahwa konversi hutan hujan dan hutan karet menjadi perkebunan karet dan kelapa sawit menyebabkan penurunan lebih dari 50% kelimpahan kumbang dan lebih dari 75% biomassa kumbang. Perubahan ini dipengaruhi oleh perbedaan lanskap dan musim. Penurunan kelimpahan dan biomassa Chrysomelidae, Elateridae, dan Staphylinidae memiliki pola yang sama, tetapi berbeda pada Curculionidae yang menunjukkan kelimpahan tinggi di perkebunan kelapa sawit akibat introduksi penyerbuk Elaeidobius kamerunicus. Kekayaan spesies Chrysomelidae dan Curculionidae berkurang 80% pada kawasan perkebunan jika dibandingkan dengan hutan hujan, sedangkan untuk Elateridae dan Staphylinidae sekitar 70%, dengan kekayaan spesies semua Famili di hutan karet hampir sama dengan hutan hujan. Komposisi komunitas Chrysomelidae dan Curculionidae di perkebunan kelapa sawit berbeda dari tipe penggunaan lahan lainnya, tetapi tidak untuk Elateridae dan Staphylinidae. Peralihan spesies (turnover) berkontribusi lebih besar pada keanekaragaman beta dibandingkan kebersarangan (nestedness), untuk semua Famili dan tipe penggunaan lahan. Kemungkinan "undersampling" komunitas kumbang di kawasan hutan hujan menunjukkan bahwa penurunan kepadatan dan keanekeragaman kumbang jauh lebih tinggi dari yang dilaporkan dalam penelitian ini, terutama pada Famili dengan banyak spesies tersembunyi seperti Staphylinidae. Penelitian ini merupakan laporan pertama yang membuktikan adanya respon heterogen dari kumbang terhadap perubahan penggunaan lahan di Sumatra, Indonesia.