Print PageAs human populations continue to grow and spread across the landscape, we partition remaining native ecosystems into small patches surrounded by human influence. Many studies focus on diurnal species living within a landscape fragmented by agriculture, but in Colorado, there is a unique focus on preserving patches of native ecosystem within the surrounding urban/suburban landscape. We focus on a group of nocturnal organisms, moths, which may respond differently to habitat fragmentation than their diurnal counterparts, butterflies. While butterflies generally lose species richness as habitat size decreases, moths do not respond to habitat loss as predictably. Instead, moth distribution has been attributed to vegetation composition. In urban/suburban systems, moths may also be affected by surrounding light from the matrix. The purpose of our study is to understand the drivers of moth community structure in urban/suburban systems by investigating the roles of patch size, vegetation composition, and light pollution on the species abundance and richness of moth communities. We sampled moth communities in 17 sites surrounded by human development two times in the summer of 2011. Additionally, we measured the area, habitat composition, and light levels in each site.
Results/Conclusions
We found no relationship between area, habitat composition, and light pollution, which allowed us to independently test these effects on moth abundance. As predicted, moth abundance was not dependent on patch size. Furthermore, moth abundance was not dependent on the amount of light pollution present at a site using both luminance and illuminance to measure light levels. Moth abundance was dependent on the amount of herbaceous plant cover, which suggests that vegetation composition may be an important driver of moth community structure. Sites with higher forb cover had more moths present while sites with more grass cover had fewer moths.
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