| 要旨トップ | 目次 | | 日本生態学会第73回全国大会 (2026年3月、京都) 講演要旨 ESJ73 Abstract

一般講演（口頭発表） I01-05 （Oral presentation）

#### Biodiversity in abandoned oil palm plantation: how much did dung beetle diversity recover after 15-year abandonment?【E】

*Arief aiman BIN LUKHMAN（Hiroshima University）, Natsuki KOMADA（Hiroshima University）, Miyabi NAKABAYASHI（Hiroshima University）, Frisco NOBILLY（Universiti Putra Malaysia）, Badrul AZHAR（Universiti Putra Malaysia）, Maisarah BURHANUDDIN（Universiti Putra Malaysia）, Norhisham RAZI（Universiti Putra Malaysia）, Shuhaimi AB RAHIM（Universiti Putra Malaysia）, Tetsuro HOSAKA（Hiroshima University）

Oil palm cultivation has been the main driver of tropical deforestation over the past several decades, leading to loss of biodiversity. However, increasing areas of abandoned oil palm plantations have emerged due to socioeconomic transitions, which may contribute to biodiversity recovery. Understanding the extent to which abandoned plantations can support biodiversity compared to actively managed systems is essential for landscape restoration and conservation planning. Focusing on dung beetles, known as excellent bioindicators in tropical forests, this study compared total abundance, species diversity and composition between one 15-year abandoned plantation (AB: 20 sampling points) and two actively-managed plantations (MA1: 12 and MA2: 42 sampling points) in University Putra Malaysia. We hypothesized that actively-managed plantations would exhibit higher dung beetle abundance and distinct community composition compared to abandoned plantation. We sampled dung beetles with yellow pan traps and pitfall traps (with and without cow dung bait) each for 48-hours at all 74 sampling points. In contrast to our expectation, AB exhibited lower mean abundance of dung beetles per trap than MA1 and MA2. Also, AB showed no significant differences in species number and Shannon diversity per trap compared to MA1 and MA2. Rarefaction species richness also showed insignificant differences among plantations. However, AB differed significantly in species composition from MA1 and MA2. SIMPER analysis showed that several dominant species contributed strongly to the dissimilarity between AB and the actively managed plantations was driven primarily by Onthophagus sp. 1. Overall, our 15-year abandoned plantation had similar or even lower abundance and species richness of dung beetles than actively managed plantations (MA1 and MA2). This might be partly due to the location of our plantations; MA1 and MA2 were closer to secondary forests than AB. The proximity to forests can increase the abundance of generalist mammals. Indeed, we could observe higher number of mammals in MA1 and MA2 than AB, which may support a higher abundance of dung beetles with their dung. Therefore, our results might be affected by landscapes surrounded by the plantations. Even if it is the case, our results clearly indicate that 15 years of abandonment has little impacts on recovery of dung beetle abundance and species richness in isolated plantation. A longer-term monitoring is definitely needed to track the recovery process of dung beetle diversity and measure how many years it will take for the full recovery.

日本生態学会