Laboratorio Ecotono, INIBIOMA, CONICET-Universidad Nacional del Comahue, S. C. de Bariloche, Río Negro, Argentina.
J Insect Sci. 2010;10:37. doi: 10.1673/031.010.3701.
Wildfires are one of the major disturbances in the dynamics of forests and shrublands. However, little is known about their effects on insect communities that contribute to faunal biodiversity and play key roles in the ecosystem's dynamics. An intense and widespread fire occurred in 1999 in the Nahuel Huapi National Park in the Andean forest in northern Patagonia, Argentina. This fire affected adjacent, but different, habitat types. After the fire, beetle abundance, species richness and assemblage composition were compared among three habitats that were structurally different before the fire. These habitats were: 1) evergreen forest dominated by Nothofagus dombeyi (Mirb.) Oerst. (Fagales: Nothofagaceae), 2) a mixed forest of the evergreen conifer Austrocedrus chilensis (D. Don) Pic. Serm. and Bizzarri (Pinales: Cupressaceae) and N. dombeyi and 3) a shrubland with a diverse community of shrub species. The relationship between beetle diversity and vegetation structure was investigated over three consecutive years. Ground beetles were collected by pitfall traps, and plant species richness, vegetation cover, and height were measured. Beetle communities varied more over years between habitats during the early regeneration after fire. There was a shift in beetle assemblage composition with time after the fire in all habitat types, probably due to similar colonization rates and microclimatic conditions. Therefore, beetle succession was more influenced by recolonization and survivorship, accompanied by climatic conditions and recovery rate of plant communities over time, than it was influenced by pre-fire habitat conditions. These results suggest that in NW Patagonia, wildfire can have a substantial, short-term impact on beetle abundance and species composition. The pre-fire conditions of each habitat type determined the structure of post-fire communities of plants but not beetle assemblages. Wildfires produce simplification and homogenization of habitat types, and this was reflected by beetle diversity.
野火是森林和灌木动态的主要干扰因素之一。然而，对于昆虫群落的影响知之甚少，这些昆虫群落有助于动物区系的生物多样性，并在生态系统的动态中发挥关键作用。1999 年，阿根廷巴塔哥尼亚北部安第斯山脉的纳韦尔瓦皮国家公园发生了一场强烈而广泛的火灾。这场火灾影响了毗邻但不同的栖息地类型。火灾后，比较了三种在火灾前结构不同的栖息地中的甲虫丰度、物种丰富度和组合组成。这些栖息地是：1）由 Nothofagus dombeyi（Mirb.）Oerst.（山毛榉目：山毛榉科）为主的常绿森林，2）由常绿针叶树 Austrocedrus chilensis（D. Don）Pic. Serm. 和 Bizzarri（柏目：柏科）和 N. dombeyi 组成的混合林，3）以多种灌木物种为特征的灌木林地。在火灾后的三年内，研究了甲虫多样性与植被结构之间的关系。使用陷阱收集地面甲虫，测量植物物种丰富度、植被覆盖度和高度。火灾后早期再生过程中，不同栖息地之间的甲虫群落变化在三年内变化更大。在所有栖息地类型中，随着时间的推移，火灾后甲虫组合组成发生了变化，可能是由于相似的定居率和微气候条件。因此，与火灾前栖息地条件相比，甲虫的演替更多地受到再定居和存活的影响，同时还受到气候条件和植物群落的恢复速度的影响。这些结果表明，在巴塔哥尼亚西北部，野火可能会对甲虫的丰度和物种组成产生重大的短期影响。每个栖息地类型的火灾前条件决定了火灾后植物群落的结构，但不决定甲虫群落的结构。野火导致栖息地类型的简化和同质化，这反映在甲虫多样性上。
