Comparative Chloroplast Genomics of Seven Endangered Cypripedium Species and Phylogenetic Relationships of Orchidaceae.

The species in the genus Cypripedium (Orchidaceae) are considered endangered, mainly distributed in the temperate regions of the Northern Hemisphere, with high ornamental and economic value. Despite previous extensive studies based on both morphology and molecular data, species and sections relationships within Cypripedium remain controversial. Here, we employed two newly generated Cypripedium chloroplast genomes with five other published genomes to elucidate their genomic characteristics. The two genomes were 162,773-207,142 bp in length and contained 128-130 genes, including 82-84 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. We identified 2,192 simple sequence repeats, 786 large repeat sequences, and 7,929 variable loci. The increase of repeat sequences (simple sequence repeats and large repeat sequences) causes a significant amplification in the chloroplast genome size of Cypripedium. The expansion of the IR region led to the pseudogenization or loss of genes in the SSC region. In addition, we identified 12 highly polymorphic loci (Pi > 0.09) suitable for inferring the phylogeny of Cypripedium species. Based on data sets of whole chloroplast genomes (IRa excluded) and protein-coding sequences, a well-supported phylogenetic tree was reconstructed, strongly supporting the five subfamilies of Orchidaceae and the genus Cypripedium as monophyletic taxa. Our findings also supported that C. palangshanense belonged to sect. Palangshanensia rather than sect. Retinervia. This study also enriched the genomic resources of Cypripedium, which may help to promote the conservation efforts of these endangered species.

Photosynthetic regulation in fluctuating light under combined stresses of high temperature and dehydration in three contrasting mosses.

Photosynthesis regulation is fundamental for the response to environmental dynamics, especially for bryophytes during their adaptation to terrestrial life. Alternative electron flow mediated by flavodiiron proteins (FLV) and cyclic electron flow (CEF) around photosystem I (PSI) play seminal roles in the response to abiotic stresses in mosses; nevertheless, their correlation and relative contribution to photoprotection of mosses exposed to combined stresses remain unclear. In the present study, the photosynthetic performance and recovery capacity of three moss species from different growth habitats were examined during heat and dehydration with fluctuating light. Our results showed that dehydration at 22 °C for 24 h caused little photodamage, and most of the parameters recovered to their original values after rehydration. In contrast, dehydration at 38 °C caused drastic injuries, especially to PSII, which was mainly caused by the inactivation of non-photochemical quenching (NPQ). Dehydration also induced a high accumulation of O2- and H2O2. A consistently higher CEF as well as a positive correlation between CEF and FLV was observed in resistant R. japonicum, implying CEF played a more important protective role for R. japonicum. In H. plumaeforme and P. cuspidatum, the positive relationship under mild stress switched to negative when stress became severe. Therefore, FLV pathway was sensitive to environmental fluctuations and maybe less efficient than CEF thus, readily to be lost during land colonization and evolution in angiosperms. Our work provides insights into the coordination of various pathways to fine-tune photosynthetic protection and can be used as a basis for species screening and development of breeding strategies for degraded ecosystem restoration with pioneering mosses.

Exploring cryptic biodiversity in a world heritage site: a new pitviper (Squamata, Viperidae, Crotalinae) from Jiuzhaigou, Aba, Sichuan, China.

This study presents a comprehensive morphological comparison along with molecular phylogeny of the genus Gloydius based on five mitochondrial genes (12S, 16S, COI, cytb, and ND4). The specimens collected from Jiuzhaigou National Nature Reserve are shown to be a new species, Gloydiuslateralis sp. nov. Zhang, Shi, Jiang & Shi based on a combination of morphological and molecular accounts. G.lateralis sp. nov. differs from other congeneric species by a series of diagnostic morphological characteristics and forms a strongly supported monophyletic group. The new species is phylogenetically closely related to G.swild, another recently described species from Heishui, Aba, Sichuan.

Photosynthetic regulation in response to fluctuating light conditions under temperature stress in three mosses with different light requirements.

Under natural field conditions, mosses experience fluctuating light intensities combined with temperature stress. Alternative electron flow mediated by flavodiiron proteins (FLVs) and cyclic electron flow (CEF) around photosystem I (PSI) allow mosses to growth under fluctuating light conditions. However, little is known about the roles of FLVs and CEF in the regulation of photosynthesis under temperature stress combined with fluctuating light. Here, we measured chlorophyll fluorescence and P700 redox state under fluctuating light conditions at 4 °C, 20 °C, and 35 °C in three mosses with different light requirements. Upon a sudden increase in light intensity, electron flow from photosystem II initially increased and then gradually decreased at 20 °C and 35 °C, indicating that the operation of FLV-dependent flow lasted much longer than previously thought. Furthermore, the absolute rates of FLV-dependent flow and CEF were enhanced under fluctuating light at 35 °C, pointing to their important roles in photoprotection when exposed to fluctuating light at moderate high temperature. Furthermore, the downregulation of FLV activity at 4 °C was partially compensated for by enhanced CEF activity. These results suggested the subtle coordination between FLV activity and CEF under fluctuating light and temperature stress. Racomitrium japonicum and Hypnum plumaeforme, which usually grow under relatively high light levels, exhibited higher FLV activity and CEF than the shade-grown moss Plagiomnium ellipticum. Based on our results, we conclude that photosynthetic acclimation to fluctuating light and temperature stress in different mosses is largely linked to the adjustment of FLV activity and CEF.

Predicting the responses of subalpine forest landscape dynamics to climate change on the eastern Tibetan Plateau.

Subalpine vegetation across the Tibetan Plateau is globally one of the most sensitive to climate change. However, the potential landscape-scale effects of climate change on subalpine forest dynamics remain largely unexplored. Here, we used a forest landscape model (LANDIS-II) coupled with a forest ecosystem process model (PnET-II) to simulate forest dynamics under future climate change in Jiuzhaigou National Nature Reserve in the eastern subalpine region of the Tibetan Plateau. We examined changes in the composition, distribution and aboveground biomass of cold temperate coniferous forests, temperate coniferous forests, deciduous broad-leaved forests and redwood forest under four climate change scenarios (RCP2.6, RCP4.5, RCP8.5 and the current climate) from 2016 to 2096. Our model predicts that by 2096, (i) cold temperate coniferous forests will expand and increase by 7.92%, 8.18%, 8.65% and 7.02% under current climate, RCP2.6, RCP4.5 and RCP8.5 scenarios, respectively; (ii) distribution of forests as a whole shows upward elevational range shift, especially under RCP8.5 scenario and (iii) total aboveground biomass slowly increases at first and then decreases to 12%-16% of current distribution under RCPs. These results show that climate change can be expected to significantly influence forest composition, distribution and aboveground biomass in the subalpine forests of eastern Tibetan Plateau. This study is the first to simulate forest dynamics at the landscape scale in subalpine areas of the Tibetan Plateau, which provides an important step in developing more effective strategies of forest management for expected climate change, not only in China but also around the world.

Research on the Industrial Energy Eco-Efficiency Evolution Characteristics of the Yangtze River Economic Belt in the Temporal and Spatial Dimension, China.

Based on the panel data of the 11 provinces along the Yangtze River Economic Belt from 1997 to 2015, the super slack-based model (Super-SBM) model is adopted to calculate the provincial-level eco-efficiency of industrial energy. While bringing in time series analysis and spatial differentiation feature analysis, the traditional and spatial Markov probability transition matrix is established. This study delves into the spatial-temporal dynamic evolution traits of the eco-efficiency of industrial energy along the Yangtze River Economic Belt. According to the results: the eco-efficiency of industrial energy of the Yangtze River Economic Belt manifests "single crest" evolution and distribution traits from left to right and top to bottom, indicating that the eco-efficiency of industrial energy of the Yangtze River Economic Belt is steadily improving gradually. However, the overall level is still low and there is still ample room for the improvement of the eco-efficiency of industrial energy. Furthermore, the eco-efficiency of industrial energy along the Yangtze River Economic Belt is elevating. The geographical spatial pattern plays a pivotal role in the spatial and temporal evolution of eco-efficiency of industrial energy, and the spatial agglomeration traits are noticeable.

A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins.

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment.