Perfecto Ivette, Vandermeer John
School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109, U.S.A., email
Department of Biology, University of Michigan, Ann Arbor, MI 48109, U.S.A.
Conserv Biol. 2002 Feb;16(1):174-182. doi: 10.1046/j.1523-1739.2002.99536.x.
Conservation efforts in fragmented landscapes frequently focus on characteristics of the habitat fragments. We propose that the matrix within which habitat fragments occur is of equal importance and focus on quality of the matrix as an interesting variable. We studied ground-foraging ants in isolated montane forest fragments in the matrix of coffee agroecosystems of southwestern Chiapas, Mexico. We sampled the ants, with tuna fish as bait, in plots at various distances from a forest fragment (2-750 m) on two farms, one an organic farm with considerable shade, the other a conventional farm with only spotty shade. Each plot contained a grid of 49 ( 7 × 7) or 100 (10 × 10) baits. The species richness of ground-foraging ants was not significantly different between the forest fragment and the high-quality matrix, but it was significantly lower in the low-quality matrix than in the forest. Furthermore, species richness decreased with distance from the forest fragment in both matrix types. However, the rate of decrease in species richness was greater in the conventional farm ( poor-quality matrix) than in the organic farm ( high-quality matrix), suggesting that the quality of the agricultural matrix is important for the conservation of ant diversity.
在破碎化景观中的保护工作通常聚焦于栖息地片段的特征。我们认为，栖息地片段所处的基质同样重要，并将基质质量作为一个有趣的变量加以关注。我们研究了墨西哥恰帕斯州西南部咖啡农业生态系统基质中孤立山地森林片段里的地面觅食蚂蚁。我们在两个农场距离森林片段不同距离（2 - 750米）的样地中，用金枪鱼作为诱饵对蚂蚁进行采样，一个是有大量遮荫的有机农场，另一个是只有零星遮荫的传统农场。每个样地包含一个由49个（7×7）或100个（10×10）诱饵组成的网格。地面觅食蚂蚁的物种丰富度在森林片段和高质量基质之间没有显著差异，但在低质量基质中显著低于森林中的。此外，在两种基质类型中，物种丰富度都随着与森林片段距离的增加而降低。然而，传统农场（低质量基质）中物种丰富度的下降速率比有机农场（高质量基质）更大，这表明农业基质的质量对蚂蚁多样性的保护很重要。
