Variation in coprophagous beetle (Coleoptera: Scarabaeidae and Hybosoridae) abundance and richness after the 2019/20 megafires at Mt. Kaputar National Park and Pilliga Nature Reserve in New South Wales, Australia

This study examines the impact of fire on the assemblages of coprophagous beetles at two woodland locations: Mt. Kaputar National Park and Pilliga Nature Reserve in New South Wales, Australia. At each location, sites burnt by wildfire in 2019/2020 were classified by severity level (low, medium, and high) and sampled systematically, with unburnt sites used as a control. Beetle abundance and richness were recorded for each site and severity level. Statistical analyses demonstrated significant variations in beetle abundance across fire severities at both locations, with distinct species-specific responses to fire severity. Species like Onthophagus squalidus and Liparochrus sp. at Mt. Kaputar were found in higher abundance within unburnt, low severity, and medium severity areas. At Pilliga, species like Onthophagus consentaneus and Onthophagus dandalu were found in higher abundance within unburnt or low severity areas and Onthophagus taurus and Onthophagus tenebrosus were found in higher abundance within high severity areas. It was found that increased fire frequency led to reduced beetle abundance at both locations, wildfire frequency also had a negative effect on beetle abundance. However, prescribed fires had no effect on beetle abundance. As fire frequency increases, it will likely lead to lower beetle abundance and increase the risk of beetle extinction.

本研究以澳大利亚新南威尔士州的卡普塔山国家公园（Mt. Kaputar National Park）与皮利加自然保护区（Pilliga Nature Reserve）两处林地为研究对象，探讨火灾对食粪甲虫（coprophagous beetles）群落组成的影响。在每个研究区域内，将2019/2020年受野火影响的样地按火灾烈度划分为轻度、中度和重度三个等级，并开展系统采样，同时以未受火烧的样地作为对照。记录各样地及各火灾烈度等级下的甲虫个体丰度与物种丰富度。统计分析结果显示，两处研究区域的甲虫个体丰度均随火灾烈度呈现显著差异，且不同物种对火灾烈度存在特异性响应。在卡普塔山国家公园，污色嗡蜣螂（Onthophagus squalidus）与Liparochrus属未定种（Liparochrus sp.）在未受火烧、轻度和中度火烧区域的个体丰度更高。在皮利加自然保护区，相合嗡蜣螂（Onthophagus consentaneus）和丹达卢嗡蜣螂（Onthophagus dandalu）在未受火烧或轻度火烧区域的个体丰度更高，而金牛嗡蜣螂（Onthophagus taurus）和暗色嗡蜣螂（Onthophagus tenebrosus）则在重度火烧区域的个体丰度更高。研究发现，两处区域的甲虫个体丰度均随火灾发生频率的增加而降低，野火频率同样对甲虫丰度产生负面影响；但计划火烧（prescribed fires）对甲虫丰度无显著影响。随着火灾频率的升高，甲虫个体丰度大概率会进一步降低，同时甲虫物种灭绝的风险也会上升。