# Anthropogenic Impacts on Bark and Ambrosia Beetle Assemblages in Tropical Montane Forest in Northern Borneo

## TL;DR

This study shows how human activities like logging and rubber plantations affect bark and ambrosia beetle diversity in Borneo forests.

## Contribution

The study reveals how anthropogenic activities alter beetle assemblages in tropical montane forests.

## Key findings

- Beetle species composition was highly unpredictable across primary, disturbed, and rubber plantation forests.
- Rubber plantations had the highest beetle abundance and species count, while disturbed forests had the lowest.
- Indigenous forest use and open canopy structures in rubber plantations significantly influenced beetle distributions.

## Abstract

This study investigates how bark and ambrosia beetles, which bore into the bark and wood of trees and logs, vary in their species composition and distribution across three types of forests in southern Sabah, Malaysia: primary forest, disturbed forest, and rubber plantation. Using ethanol-baited traps, researchers collected data biweekly over three years. The findings revealed a rich diversity of the beetles in all types of forest, yet the species composition was highly unpredictable between forest types. The study demonstrated that anthropogenic activities, such as the indigenous use of forests for fuel and the conversion of forest into rubber plantation, significantly affect the distribution and abundance of these beetles. These changes have crucial implications for forest health and ecosystem stability. By understanding how different forest types and anthropogenic activities impact these insects, this research provides valuable insights for managing forests and protecting biodiversity in Malaysia’s tropical ecosystems.

Anthropogenic disturbances, such as forest conversion, have a profound impact on species distributions and biodiversity in tropical forests. This study aimed to determine the diversity and distribution of bark and ambrosia beetles (Curculionidae: Scolytinae and Platypodinae) across three forest types: Primary Forest (PF), Disturbed Forest (DF), and Rubber Plantation (RP) in southern Sabah, Malaysia. We analyzed biweekly data obtained from ethanol-baited traps over three years, from April 2017 to May 2020, which included 7257 individuals from 154 species. The dominant species remained the same across all forest types. However, species composition was highly stochastic and unpredictable between forest types. The abundance and number of species were highest in RP but lowest in DF. Indigenous forest use in DF mostly for fuel likely reduced the resources for the beetles. Open canopy structure in RP probably increased the number of flying beetles. Although adjacent to PF, RP displayed a distinct species composition predominantly associated with rubber trees. These findings underscore the anthropogenic impact on beetle assemblages due to forest use and emphasize the need for sustainable forest management practices to prevent biodiversity loss and maintain ecosystem stability.