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

Abstract

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.

Determinants of invertebrate community structure in glacial‐melt streams of southeast Tibet

“…Our results that indicated presence–absence taxa composition gradients were best predicted by water temperature or a combination of water temperature and Pfankuch scores is consistent with the predictions of the Milner, Brittain, et al., (2001) model and with the relationships documented by others working in glacial‐melt streams in Tibet (Xu et al., 2018), Ecuador (Jacobsen et al., 2010), and Norway (Brittain et al., 2001). However, our finding that relative abundance taxa composition gradients were more strongly correlated with habitat variables other than water temperature and Pfankuch scores were inconsistent with the Milner, Brittain, et al., (2001) model, but were similar to the results of others working in Ecuador (Kuhn et al., 2011), Svalbard (Blaen et al.,2014), and Iceland (Gislason et al., 2001).…”

“…Habitat conditions and associated invertebrate relationships have been examined within high elevation glacial‐melt streams (>4,000 m a.s.l.) on the Tibetan Plateau (Hamerlik & Jacobsen, 2012; Jiang et al., 2013; Laursen et al., 2015; Murakami et al., 2012; Xu et al., 2018). However, none of these studies examined the full range of water temperature, channel stability, and distance from the glacier as described in the Milner, Brittain, et al., (2001) model.…”

“…However, none of these studies examined the full range of water temperature, channel stability, and distance from the glacier as described in the Milner, Brittain, et al., (2001) model. Findings from Tibetan Plateau stream studies that are supportive of the Milner, Brittain, et al., (2001) model predictions include: (1) reduced taxa richness at sites with coldest water temperatures closest to the glacier (Murakami et al., 2012); (2) invertebrate taxa richness and Chironomidae taxa composition that differed longitudinally from the headwaters to the downstream reaches (Hamerlik & Jacobsen, 2012; Jiang et al., 2013); and (3) invertebrate taxa composition that was influenced by water temperature and substrate stability (Xu et al., 2018).…”

Aquatic insect communities in headwater streams of Ciliwung River watershed, West Java, Indonesia

“…The fact that aquatic insect biodiversity was extremely high in headwater streams suggests that watershed preservation programs may be important to conserve freshwater biodiversity. Meanwhile, highland running-water biodiversity has gained growing interest around the world, because of their more pristine conditions and higher sensitivity to environmental changes compared to lowland rivers (Xu et al 2018). Tropical freshwaters are among the most threatened ecosystems, experiencing biodiversity loss at alarming rates (Sundar et al 2020).…”

Responses of Macroinvertebrate Assemblages to Flow in the Qinghai‐Tibet Plateau: Establishment and Application of a Multi‐Metric Habitat Suitability Model

“…The QTP is of critical ecological importance, possessing diverse biomes (alpine tundra, montane forest, subtropical dry forest, and tropical montane rainforest; Ni & Herzschuh, 2011), and encompasses several biodiversity hotspots (e.g., in the mountainous areas of Central Asia, Himalayas, Indo‐Burma, and Hengduan range; Tang et al., 2006). The river and stream biota in the QTP are highly specialized owing to the unique conditions, making them especially vulnerable to external disturbances (Favre et al., 2015; Xu et al., 2018; Yao et al., 2012). Environmental conditions that have been intensively modified by anthropogenic activities and climate warming during recent decades include instream flows, jeopardizing the services provided by alpine rivers with healthy ecosystems (Poff et al., 1997; Wenger et al., 2011).…”