Husband Danielle M, McIntyre Nancy E
Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409-3131, USA.
Insects. 2021 May 11;12(5):431. doi: 10.3390/insects12050431.
In western Texas, most wetlands are fed from precipitation runoff, making them sensitive to drought regimes, anthropogenic land-use activities in their surrounding watersheds, and the interactive effect between these two factors. We surveyed adult odonates in 133 wetlands (49 in grassland settings, 56 in cropland, and 28 in urban areas) in western Texas from 2003-2020; 33 species were recorded. Most species were widespread generalists, but urban wetlands had the highest species richness, as well as the most unique species of any of the three wetland types. Non-metric, multidimensional scaling ordination revealed that the odonate community in urban wetlands was distinctly different in composition than the odonates in non-urban wetlands. Urban wetlands were smaller in surface area than the other wetland types, but because they were fed from more consistently available urban runoff rather than seasonal precipitation, they had longer hydroperiods, particularly during a multi-year drought when wetlands in other land-cover contexts were dry. This anthropogenically enhanced water supply was associated with higher odonate richness despite presumably impaired water quality, indicating that consistent and prolonged presence of water in this semi-arid region was more important than the presence of native land cover within which the wetland existed. Compared to wetlands in the regional grassland landscape matrix, wetlands in agricultural and urban areas differed in hydroperiod, and presumably also in water quality; these effects translated to differences in the regional odonate assemblage by surrounding land-use type, with the highest richness at urban playas. Odonates in human environments may thus benefit through the creation of a more reliably available wetland habitat in an otherwise dry region.
在得克萨斯州西部，大多数湿地的水源来自降水径流，这使得它们对干旱状况、周边流域的人为土地利用活动以及这两个因素之间的相互作用很敏感。我们在2003年至2020年期间对得克萨斯州西部133个湿地（49个位于草原地区，56个位于农田，28个位于城市地区）中的成年蜻蜓目昆虫进行了调查；记录到33个物种。大多数物种分布广泛，但城市湿地的物种丰富度最高，且是三种湿地类型中拥有最独特物种的。非度量多维标度排序显示，城市湿地中的蜻蜓目昆虫群落组成与非城市湿地中的明显不同。城市湿地的表面积比其他湿地类型小，但由于它们的水源来自更稳定的城市径流而非季节性降水，因此它们的水文周期更长，尤其是在多年干旱期间，其他土地覆盖类型的湿地干涸时。尽管水质可能受到损害，但这种人为增强的供水与更高的蜻蜓目昆虫丰富度相关，这表明在这个半干旱地区，持续而长期的水的存在比湿地所在的原生土地覆盖的存在更为重要。与区域草原景观基质中的湿地相比，农业和城市地区的湿地在水文周期上存在差异，水质可能也不同；这些影响导致区域蜻蜓目昆虫群落因周边土地利用类型而有所不同，城市滩涂的物种丰富度最高。因此，在原本干旱的地区，通过创造一个更可靠的湿地栖息地，人类环境中的蜻蜓目昆虫可能会受益。
