A new species of Behningia Lestage, 1929 (Ephemerotera: Behningiidae) from China

Zhou, Xiongdong, Bisset, Mike, Xu, Mengzhen, Wang, Zhaoyin (2019): A new species of Behningia Lestage, 1929 (Ephemerotera: Behningiidae) from China. Zootaxa 4671 (3): 420-426, DOI: https://doi.org/10.11646/zootaxa.4671.3.

Macroinvertebrate Biodiversity Trends and Habitat Relationships within Headwater Rivers of the Qinghai-Tibet Plateau

Highland running-water biodiversity has gained growing interest around the world, because of the more pristine conditions and higher sensitivity to environmental changes of highland rivers compared to the lowland rivers. This study presents the findings of systematic investigations and analyses on running-water biodiversity of macroinvertebrate assemblages in the most important headwater streams in the Yalutsangpo and Sanjiangyuan River basins in the Qinghai-Tibet Plateau and the lowland headwaters of the Songhua River, Juma River, and East River during the non-flood seasons of 2012 to 2016. The results indicated that the headwaters on the plateau had a higher regional biodiversity compared to the lowland rivers with the similar flow and substrate conditions. Even though the local diversity of the highland rivers was not significantly different at each single site, the taxonomic composition was significantly different with several rarely seen species scattering among the different sites, resulting in a high regional biodiversity. The biodiversity and composition of macroinvertebrates were strongly affected by the altitude gradient and the environmental variables associated with altitude. To be specific, for the Yalutsangpo River, canonical correspondence analyses of the macroinvertebrate assemblages and their environmental variables indicated that altitude, stream condition (represented by river pattern, riverbed structures, substrate composition), and water temperature influence macroinvertebrate taxa composition. Because of the restrictive plateau conditions including low water temperature, poor aquatic and riparian vegetation, and low runoff, the macroinvertebrate assemblages showed low biodiversity and were vulnerable to potential human disturbance/climate change. Therefore, it is essential to conserve suitable conditions of the determinative environmental variables to protect the unique and high regional biodiversity of the headwaters on the Qinghai-Tibet Plateau

Evaluating the ecological health of aquatic habitats in a megacity through a multimetric index model based on macroinvertebrates

Globally, urban water bodies suffer from a variety of ecological pressures which profoundly change freshwater ecosystem services and pose a great threat to aquatic biodiversity. To identify the effects of these pressures on aquatic communities, we systematically investigated the macroinvertebrates in different water types (e.g., mountain rivers, plain rivers, lakes, and reservoirs) in all water systems in Beijing, a megacity in China, to reveal the key environmental factors and response mechanisms affecting the spatial distribution of macroinvertebrate communities. A total of 188 macroinvertebrate taxa were identified at 61 survey sections, and environmental factors such as flow velocity, water depth, water temperature, and total nitrogen content were found to substantially affect the structure and spatial distribution of the macroinvertebrate communities. A multimetric index (MMI) model based on macroinvertebrates was developed to assess the ecological quality of each water type, and the developed MMI was demonstrated to be widely applicable. In the MMI, each community metric was weighted based on the goodness of fit for each biological metric and environmental metric to obtain the observed MMI values of the measured sample sites, and further model training and prediction was performed based on all sample site data. The MMI results revealed that the overall ecological quality of mountain rivers with less anthropogenic interference was relatively good (MMI = 0.62 ± 0.28), the overall ecological quality of lakes experiencing ecological disturbance and undergoing ecological restoration practices was moderate (MMI = 0.43 ± 0.09), and the overall ecological quality of plain rivers and reservoirs with strong anthropogenic interference was relatively poor (MMI = 0.24 ± 0.12 and 0.32 ± 0.12, respectively). Specific recommendations for ecological protection of different water types were formulated, providing a scientific basis and decision-making support for urban ecological planning and sustainable development