Johnson Robert A
Zoology Department, Arizona State University, 85287-1501, Tempe, AZ, USA.
Oecologia. 1992 Jan;89(1):118-124. doi: 10.1007/BF00319023.
Pogonomyrmex rugosus and Messor pergandei are ecologically similar species of desert seed-harvester ants that coexist in numerous areas throughout the Sonoran and Mohave Deserts. However, these two species also commonly segregate along physical gradients, with each species predominating in areas that differ in soil texture and/or topographic relief. Along gradients that included bajada and alluvial flat habitats, P. rugosus occurred alone in coarse-textured soils near mountains, while M. pergandei occurred alone in finer-textured soils further away. Conversely, along a vegetation gradient that included creosote bush and saltbush habitats, P. rugosus occurred alone in finer-textured soils than those occupied by either M. pergandei alone or both species in coexistence. However, in both situations clay content was significantly higher in areas occupied by P. rugosus alone, and at the latter site clay content was correlated with relative abundance of each species. Moreover, local distribution pattern of these two species may be related to the effects of clay on water retention, with retention being highest in areas occupied by P. rugosus alone. Differences in reproductive ecology may also affect these patterns as P. rugosus reproductive flights follow summer monsoon rains, while those of M. pergandei occur during the milder winter and spring.
粗纹收获蚁（Pogonomyrmex rugosus）和珀氏收获蚁（Messor pergandei）是生态习性相似的沙漠种子收获蚁物种，它们在索诺兰沙漠和莫哈韦沙漠的许多地区共存。然而，这两个物种也通常会沿着物理梯度分离开来，每个物种在土壤质地和/或地形起伏不同的区域占主导地位。在包括山麓冲积平原和冲积平原栖息地的梯度区域中，粗纹收获蚁单独出现在山区附近质地粗糙的土壤中，而珀氏收获蚁单独出现在更远的质地较细的土壤中。相反，在包括石炭酸灌木和盐土灌木栖息地的植被梯度区域中，粗纹收获蚁单独出现的土壤质地比珀氏收获蚁单独占据或两者共存时所占据的土壤质地更细。然而，在这两种情况下，单独被粗纹收获蚁占据的区域的粘土含量明显更高，并且在后者的区域中，粘土含量与每个物种的相对丰度相关。此外，这两个物种的局半分布模式可能与粘土对保水的影响有关，单独被粗纹收获蚁占据的区域保水能力最强。生殖生态学上的差异也可能影响这些模式，因为粗纹收获蚁的婚飞在夏季季风降雨之后，而珀氏收获蚁的婚飞则发生在较温和的冬季和春季。
