The geological structure and history of mountains often cause highly complex patterns of evolution. The origin and diversity of the genus Triplophysa is considered to be closely associated with the rapid and persistent rise of the Qinghai-Tibet Plateau (QTP). Species of the genus are widely distributed in the QTP and adjacent regions, and are strongly adapted to its extreme environments. However, the Central Chinese Mountains (CCM), which are far apart from the QTP, also have many Triplophysa populations and yet their taxonomy, phylogeny and origin are unknown. We used three mitochondrial genes of 266 individuals from 29 sites in the CCM to shed light on the evolution of these Triplophysa populations. Phylogenetic analyses and species delimitation revealed seven distinct molecular operational taxonomic units (mOTUs) in the CCM, each with low genetic diversity. Molecular clock and biogeographic analyses suggested that vicariance events resulting from the rapid uplifting of the Qinling and Taihang Mountains initialized diversification in the Pliocene. During the early Pleistocene, dispersal events in the central parts of the Yellow River drainage altered genetic diversity and led to the currently observed biogeographic patterns. Our results suggest the presence of at least six species of Triplophysa in the CCM and more are likely to be discovered in the future.

No abstract

Long-term annual (1990–2010) monitoring data were analyzed to test the responses of phytoplankton biomass in three lakes in the Yungui Plateau, China, to increasing temperature and increasing nutrient concentrations. The three studied lakes (Lake Fuxian, Lake Erhai and Lake Dianchi) all exhibited significant increases in algal biomass from 1990 to 2010, with increases of 0.111 µg/L, 0.662 µg/L and 3.07 µg/L per year, respectively. The study also indicated that the relative influences of warming and nutrient concentrations on chlorophyll a concentration varied among the lakes and was dependent on trophic level and phytoplankton composition. In Lake Fuxian, the increase in algal biomass was correlated with the rapid growth of Mougeotia spp., and the total phosphorous concentration was the key factor driving this increase in algal biomass. In Lake Erhai, the dominant species shifted from Dolichospermum spp. to Microcystis spp. Additionally, the increase in algal biomass in Lake Erhai (involving mainly an increase in Microcystis spp.) was significantly associated with an increase in total nitrogen (TN) concentration. In Lake Dianchi, warming and increases in TN concentration were the strongest predictors of biomass change.