Anthropogenic disturbance driving population decline of a dominant tree in East Asia evergreen broadleaved forests over the last 11,000 years.

Current biodiversity loss is generally considered to have been caused by anthropogenic disturbance, but it is unclear when anthropogenic activities began to affect biodiversity loss. One hypothesis suggests it began with the Industrial Revolution, whereas others propose that anthropogenic disturbance has been associated with biodiversity decline since the early Holocene. To test these hypotheses, we examined the unique vegetation of evergreen broadleaved forests (EBLFs) in East Asia, where humans have affected landscapes since the early Holocene. We adopted a genomic approach to infer the demographic history of a dominant tree (Litsea elongata) of EBLFs. We used Holocene temperature and anthropogenic disturbance factors to calculate the correlation between these variables and the historical effective population size of L. elongata with Spearman statistics and integrated the maximum-entropy niche model to determine the impact of climate change and anthropogenic disturbance on fluctuation in its effective population size. We identified 9 well-defined geographic clades for the populations of L. elongata. Based on the estimated historical population sizes of these clades, all the populations contracted, indicating persistent population decline over the last 11,000 years. Demographic history of L. elongata and human population change, change in cropland use, and change in irrigated rice area were significantly negatively correlated, whereas climate change in the Holocene was not correlated with demographic history. Our results support the early human impact hypothesis and provide comprehensive evidence that early anthropogenic disturbance may contribute to the current biodiversity crisis in East Asia.

Divergent Synthesis of Highly Substituted Tetrahydroquinolines and Cyclopentenes via Lewis Base Catalyzed Switchable [4 + 2] and [3 + 2] Annulations of MBH-Carbonates with Activated Olefins.

A highly selective and divergent synthesis which enabled access to various complex compounds is highly attractive in organic synthesis and medicinal chemistry. Herein, we developed an effective method for divergent synthesis of highly substituted tetrahydroquinolines via Lewis base catalyzed switchable annulations of Morita-Baylis-Hillman carbonates with activated olefins. The reaction displayed switchable [4 + 2] or [3 + 2] annulations via catalyst or substrate control, providing a diverse range of architectures which contained highly substituted tetrahydroquinolines or cyclopentenes with three contiguous stereocenters bearing a quaternary carbon center in high yields with excellent diastereoselectivities and regioselectivities. Furthermore, synthetic utility of this strategy was further highlighted by gram-scale experiments and simple transformations of the products.

Differential distribution shifts in two subregions of East Asian subtropical evergreen broadleaved forests-a case of Magnoliaceae.

Aim: East Asian subtropical evergreen broad-leaved forests (EBLFs) are composed of western and eastern subregions with different topographical and environmental conditions. The distribution shifts over time of plants in the two subregions are predicted to be different, but the difference has seldom been investigated. Methods: Potential distributions of 53 Magnoliaceae species (22 in the western and 31 in the eastern subregion) during the last glacial maximum (LGM), present, and the 2070s were predicted using MaxEnt based on 58 environmental variables. The changes in the distribution range size and centroid over time were analyzed. Species-level potential habitats were overlaid to uncover species diversity distribution, and the distributions over time were overlaid to discover long-term refugia. Results: At present, the potential distributions are significantly larger than those shown by the occurrence points. During the LGM, 20/22 species in the western subregion experienced increases in range size through downwards and southward migrations, while decreases in range size in the eastern subregion (27/31 species) were accompanied by northward and eastward migrations. In the future, range size declines and northward shifts will both be found; northwestward shifts will exist in most (20/22 species) species in the western subregion, while both northwest- and northeastward shifts will occur in the eastern subregion. The diversity hotspots experienced a slight southward shift in the past and upwards to the mountain region in the future in the western subregion; in the eastern subregion, shrinks occurred in eastern China in the past and shrinks were shown in all regions in the future. Long-term refugia-preserving diversity was found in the mountains across the entire EBLFs region. Main conclusions: Significant differences in distribution shifts from past to present and similar distribution shifts from present to future are revealed in the two subregions. Species diversity in both subregions experienced no significant shifts from past to future, and Magnoliaceae plants could be preserved in mountainous regions throughout the EBLFs.

Monsoon intensification in East Asia triggered the evolution of its flora.

Introduction: East Asia (EA), which falls within the region of the Asian monsoon that is composed of the East Asia monsoon (EAM) and the Indian monsoon (IM), is known for its high species diversity and endemism. This has been attributed to extreme physiographical heterogeneity in conjunction with climate and sea-level changes during the Pleistocene, this hypothesis has been widely proven by phylogeographic studies. Recently, dated phylogenies have indicated that the origins (stem age) of the flora occurred after the Oligocene-Miocene boundary and are related to the establishment of the EAM. Methods: Hence, this study further examined whether the strengthening of the monsoons triggered floral evolution via a meta-analysis of the tempo-spatial pattern of evolutionary radiation dates (crown ages) of 101 endemic seed plant genera. Results: Taxonomic diversification began during the late Eocene, whereas the accumulated number of diversifications did not significantly accelerate until the late Miocene. The distribution of the weighted mean and the average divergence times in the EAM, IM, or transitional regions all fall within the mid-late Miocene. Fossils of the Tertiary relict genera are mostly and widely distributed outside EA and only half of the earliest fossils in the EA region are not older than Miocene, while their divergence times are mostly after the late Miocene. The pattern of divergence time of monotypic and polytypic taxa suggest the climatic changes after the late Pliocene exert more influence on monotypic taxa. Discussion: The two key stages of floral evolution coincide with the intensifications of the EAM and IM, especially the summer monsoon which brings a humid climate. An integrated review of previous studies concerning flora, genus, and species levels further supports our suggestion that monsoon intensification in EA triggered the evolution of its flora.

Diversification of East Asian subtropical evergreen broadleaved forests over the last 8 million years.

The evolution of subtropical evergreen broadleaved forests (EBLFs) in East Asia is interesting while complicated. Genus-level phylogenies indicate that the origins of EBLFs could trace back to the Oligocene-Miocene boundary or even the Eocene, while population-level phylogeographic evidence suggests that they diversified after the Miocene, particularly in the Pleistocene. Here, we review the origins of dominant plant species to better understand the evolution of EBLFs. We compiled published estimates of the timing of origin of dominant species and diversification of evergreen relict genera from East Asian EBLFs. We also traced and visualized the evolution of EBLFs in the region using dated phylogenies and geographic distributions of the reviewed taxa. Most (76.1%) of the dominant species originated after the late Miocene, ca. 8 million years ago. Of the 10 evergreen relict genera, eight diverged near the late Miocene-Pliocene boundary or during the late Pliocene, and the remaining two diverged during the Pleistocene. Over the past 8 million years, geo-climatic changes have triggered origins of most of the dominant EBLF species and provided refugia for evergreen relict genera. Three pulsed phases of evolution are suggested by genetic studies at the genus, species, and population levels. Fossil evidence and spatiotemporal investigations should be integrated to fully understand the evolution of EBLFs in East Asia.

Insights Into the Significance of the Chinense Loess Plateau for Preserving Biodiversity From the Phylogeography of Speranskia tuberculata (Euphorbiaceae).

The significance of the Chinese Loess Plateau (CLP) in maintaining biodiversity for northern China has rarely been shown, as previous phylogeographic studies are mostly woody species and they have revealed that Quaternary refugia are mainly located in mountain regions. We selected a drought-enduring endemic herb, Speranskia tuberculata (Euphorbiaceae), to determine its glacial refugia and postglacial demographic history. To this end, we sampled 423 individuals from 38 populations covering its entire geographic distribution. Three chloroplast DNA (cpDNA) fragments, two low-copy nuclear genes, and six nuclear microsatellites (nSSRs) were used and supplemented with ecological niche modeling (ENM) to infer the phylogeographic history of this species. Populations with private haplotypes and high haplotype diversity of cpDNA are mainly located in the CLP or scattered around northeastern China and the coastal region. Spatial expansion, detected using a neutrality test and mismatch distribution, may have resulted in a widely distributed ancestral cpDNA haplotype, especially outside of the CLP. For nuclear DNA, private haplotypes are also distributed mainly in the CLP. In nSSRs, STRUCTURE clustering identified two genetic clusters, which are distributed in the west (western cluster) and east (eastern cluster), respectively. Many populations belonged, with little to no admixture, to the western cluster while (hardly) pure populations of the eastern cluster were barely found. Genetic differentiation is significantly correlated with geographic distance, although genetic diversity is uniformly distributed. ENM suggests that the distribution of S. tuberculata has recently expanded northwards from the southern CLP, whereas it has experienced habitat loss in the south. Thus, S. tuberculata populations probably survived the last glacial maximum (LGM) in the southern CLP and experienced post-glacial expansion. Wind-dispersed pollen could bring the majority of genotypes to the front during spatial expansion, resulting in uniformly distributed genetic diversity. Based on evidence from molecular data and vegetation and climate changes since the LGM, we conclude that drought-enduring species, especially herbaceous species, are likely to have persisted in the CLP during the LGM and to have experienced expansion to other regions in northern China.

Distinct late Pleistocene subtropical-tropical divergence revealed by fifteen low-copy nuclear genes in a dominant species in South-East China.

In East Asia, genetic divergence is usually considered to be correlated to different floristic regions, however, subtropical-tropical divergence is largely ignored, compared to widely explored temperate-subtropical divergence. Lindera aggregata (Lauraceae), a dominant species in South-East China was selected to address this issue. Fifteen low-copy nuclear genes (LCGs) and four chloroplast DNA (cpDNA) fragments were used to detect its evolutionary history. In LCGs, STRUCTURE and dated Bayesian phylogeny analyses detect distinct subtropical-tropical divergence since late Pleistocene. Approximate Bayesian calculation (ABC) further supports the distinct subtropical-tropical divergence, and close related Taiwan and South China populations are diverged at the last interglacial. Isolation by distance, isolation by environment and isolation by resistance analyses suggest the current climatic difference rather than geographical distance contributes to the genetic differentiation. Principle component analysis shows populations of tropical cluster occur in warmer area with higher precipitation. Ancestral area reconstruction based on Bayesian phylogeny indicates that ancestral L. aggregata populations are distributed in tropical region. In cpDNA, although unique haplotypes are found in tropical region, distinct subtropical-tropical divergence is absent. In conclusion, distinct late Pleistocene subtropical-tropical divergence of L. aggregata is triggered by climate. It is likely that L. aggregata is originated in Southwest-South China and experienced hierarchical dispersal from south to north. The South China Sea land bridge has dual role in connecting or isolating Taiwan and mainland populations since the last glaciation.

Modern physical training concepts and approachs into public physical education in colleges and universities / 中国学校卫生

Abstract@#Public physical education teaching has adopted modern concepts and approachs of physical training to highlight the importance and effectiveness of physical education in colleges and universities in China. These courses have placed an emphasis on the need to attend to the structural integrity of the human body, optimizing the basic action mode and the efficient transmission of the power chain in motion. From the perspective of curriculum education, it is helpful to update ideas surrounding the public physical education curriculum in colleges and universities to enrich the content of public physical education courses provided by these institutions and to improve the scientific nature of training, while also enhancing the physical fitness of college students and promoting lifelong sports consciousness. However, there is insufficient explanation and implementation of modern physical training concepts and approachs into the teaching and process of public sports in colleges and universities. It will be beneficial to improve its top level design, increase policy support, provide better facilities, strengthen the construction of teachers, actively organize enjoyable physical fitness competitions, enrich the teaching content system and clear on the positioning of college physical education, in order to promote the fundamental tasks of school based physical education and the value of school sports. This is also important to ensure a renewal of the concept of the public physical education curriculum in our country, and encourage reform of the curriculum content, teaching mode and teaching methods, while also highlighting the essential function of physical training.

[Allelopathic effects of Miscanthus floridulus on seed germination and seedling growth of three crops]. / å·´èŒ è‰æ°´æµ¸ææ¶²å¯¹3种作物种子萌发及幼苗生长的化感作用.

Allelopathic effects of Miscanthus floridulus at different growth stages on Brassica peki-nensis, Lactuca sativa, and Oryza sativa were examined using six parameters of seed germination and seedling growth, including germination rate, germination speed index, germination index, root length, stem length, and biomass. The results showed that the allelopathic effects of M. floridulus leaf extract were stronger than that of stem extract, with the germination index and biomass of reci-pient plants treated by leaf extract being significantly lower than those treated by stem extract. The allelopathic effect of M. floridulus in the withering stage was stronger than that in the vigorous growth stage. There was a significant dose-effect relationship between the concentrations of leaf extract and the allelopathic effects on three different receptor plants. The higher the extract concentration was, the stronger the allelopathic inhibition was. Leaf extract of M. floridulus could completely inhibit all the germination indices of B. pekinensis and L. sativa at the concentrations of 0.075 and 0.10 g·mL-1, respectively. The inhibition rates of 0.10 g·mL-1 leaf extract on germination rate, germination speed index, and germination index of O. sativa were 13.8%, 27.2% and 19.3%, respectively. Leaf extract of M. floridulus could completely inhibit all the growth indices of B. pekinensis and L. sativa at the concentrations of 0.05 and 0.10 g·mL-1, respectively. However, the inhibition rates of 0.10 g·mL-1 leaf extract on root length, stem length, and biomass of O. sativa were 64.6%, 92.9% and 21.8%, respectively. In summary, according to the comprehensive allelopathy response index (SE) of seed germination and seedling growth, the susceptibility of the three tested species to the extracts of M. floridulus was B. pekinensis (Cruciferae) > L. sativa (Compositae) > O. sativa (Gramineae).

Different processes shape the patterns of divergence in the nuclear and chloroplast genomes of a relict tree species in East Asia.

Isolation by spatial distance (IBD), environment (IBE), and historical climatic instability (IBI) are three common processes assessed in phylogeographic and/or landscape genetic studies. However, the relative contributions of these three processes with respect to spatial genetic patterns have seldom been compared. Moreover, whether the relative contribution differs in different regions or when assessed using different genetic markers has rarely been reported. Lindera obtusiloba has been found to have two sister genetic clades of chloroplast (cpDNA) and nuclear microsatellite (nSSR), both of which show discontinuous distribution in northern and southern East Asia. In this study, we used the Mantel test and multiple matrix regression with randomization (MMRR) to determine the relative contributions of IBD, IBE, and IBI with respect to L. obtusiloba populations. Independent Mantel tests and MMRR calculations were conducted for two genetic data sets (cpDNA and nSSR) and for different regions (the overall species range, and northern and southern subregions of the range). We found a significant IBI pattern in nSSR divergence for all assessed regions, whereas no clear IBI pattern was detected with respect to cpDNA. In contrast, significant (or marginal) divergent IBD patterns were detected for cpDNA in all regions, whereas although a significant IBE was apparent with respect to the overall range, the effect was not detected in the two subregions. The differences identified in nSSR and cpDNA population divergence may be related to differences in the heredity and ploidy of the markers. Compared with the southern region, the northern region showed less significant correlation patterns, which may be related to the shorter population history and restricted population range. The findings of this study serve to illustrate that comparing between markers or regions can contribute to gaining a better understanding the population histories of different genomes or within different regions of a species' range.

Development of 20 chloroplast microsatellite primers in wuyao (Lindera aggregata, Lauraceae).

PREMISE OF THE STUDY: To investigate the population genetics and evolutionary history of wuyao (Lindera aggregata, Lauraceae) and other Lindera species, polymorphic chloroplast microsatellite (cpSSR) primers were developed. METHODS AND RESULTS: The complete chloroplast genome of L. glauca was used to design 74 primers for L. aggregata. Agarose gel electrophoresis and Sanger sequencing were used to select 20 polymorphic primers. These primers were then tested in 70 individuals from three populations of L. aggregata. The number of alleles ranged from two to four, and the unbiased haploid diversity index ranged from 0.457 to 0.685. Up to 17 primers successfully amplified in four other Lindera species: L. prattii, L. chunii, L. lungshengensis, and L. pulcherrima var. hemsleyana. CONCLUSIONS: The 20 primers reported here can potentially be used for future genetic studies of L. aggregata and other Lindera species.

Phylogeography of Schisandra chinensis (Magnoliaceae) Reveal Multiple Refugia With Ample Gene Flow in Northeast China.

Temperate conifers and broadleaved mixed forests in northeast China are ideal to investigate the genetic consequences of climate changes during the last glacial maximum (LGM), 29 - 16 kya. As previous studies were focused on tree species with long generation time; here, the evolutionary history of Schisandra chinensis, a climber species with a generation time of five years, was investigated using chloroplast DNA (cpDNA), nuclear single copy gene (nSCG), and nuclear single sequence repeats (nSSRs, i.e., microsatellite) markers, along with ecological niche modeling (ENM), which predicted a suitable habitat in Korea Peninsula (KP) during the LGM. Private haplotypes and high genetic diversity of both cpDNA and nSCG were mainly found in KP and Changbai Mt. (CB). Although no significant phylogeographic structure was detected in the cpDNA and nSCG, three nSSRs clusters roughly distributed in west (CB and KP), east (north China), and north (Xiaoxing'an Range, XR) regions were found in Structure analysis. The approximate Bayesian computation analysis showed the west cluster diverged at 35.45 kya, and the other two clusters at 19.85 kya. The genetic diversity calculated for each of the three markers showed no significant correlation with latitude. Genetic differentiation of nSSRs was also not correlated with geographic distance. Migrate analysis estimated extensive gene flow between almost all genetic cluster pairs and BOTTLENECK analysis showed that few populations experienced severe bottlenecks. Overall, results indicate that S. chinensis survived the LGM in situ in multiple refugia, which likely include two macrorefugia (KP and CB) and two microrefugia (XR and north China). Extensive postglacial gene flow among the three nSSRs clusters led to uniformly distributed genetic diversity and low genetic differentiation.

Twenty-seven low-copy nuclear primers for Lindera obtusiloba (Lauraceae): A Tertiary relict species in East Asia.

PREMISE OF THE STUDY: To investigate a more detailed evolutionary history of Lindera obtusiloba (Lauraceae) and other Lindera species, polymorphic low-copy nuclear primers were developed. METHODS AND RESULTS: Unigenes of the L. obtusiloba transcriptome greater than 800 bp in length were randomly chosen for initial design of 168 primers. Agarose gel electrophoresis and Sanger sequencing were used to select low-copy nuclear genes. Twenty-seven primers were obtained and were used to investigate genetic diversity in 90 individuals from 24 populations. The nucleotide diversity ranged from 2.11 × 10-3 to 8.99 × 10-3, and haplotype diversity ranged from 0.57 to 0.97. These primers were also cross-amplified in L. aggregata, L. chunii, L. erythrocarpa, and L. glauca; up to 15 primers were successfully amplified in these related species. CONCLUSIONS: This methodology is effective for development of low-copy nuclear primers. The 27 primers developed here will be useful for evolutionary studies of L. obtusiloba and other Lindera species.

Evolutionary history of a widespread tree species Acer mono in East Asia.

East Asia has the most diverse temperate flora in the world primarily due to the lack of Pleistocene glaciation and the geographic heterogeneity. Although increasing phylogeography studies in this region provided more proofs in this issue, discrepancies and uncertainty still exist, especially in northern temperate deciduous broad-leaved and coniferous mixed forest region (II). And a widespread plant species could reduce the complexity to infer the relationship between diversity and physiographical pattern. Hence, we studied the evolution history of a widespread temperate tree, Acer mono, populations in region II and the influence of physiographic patterns on intraspecific genetic diversity. Analyses of chloroplast sequences and nuclear microsatellites indicated high levels of genetic diversity. The diversity distribution was spatially heterogeneous and a latitudinal cline existed in both markers. The spatial distribution pattern between genetic diversity within A. mono and the diversity at species level was generally consistent. Western subtropical evergreen broad-leaved forest subregion (IVb) had a unique ancient chloroplast clade (CP3) and a nuclear gene pool (GP5) with dominance indicating the critical role of this area in species diversification. Genetic data and ecological niche model results both suggested that populations in region II disappeared during the last glacial maximum (LGM) and recovered from south of Changbai Mt. and the Korean Peninsula. Two distribution centers were likely during the LGM, one in the north edge of warm temperate deciduous broad-leaved forest region (III) and another in the south edge of region III. This was reflected by the genetic pattern with two spatially independent genetic groups. This study highlights the key role of region III in sustaining genetic diversity in the northern range and connecting diversity between southern and northern range. We elucidated the diversity relationship between vegetation regions which could facilitate the understanding of biodiversity origin and maintenance in East Asia.

Synthesis of porous hierarchical MgO and its superb adsorption properties.

The porous hierarchical MgO with superb adsorption properties has been synthesized by a facile and scaled-up method. The X-ray powder diffraction, electron microscopy, Fourier transformed infrared, and N2 adsorption-desorption were carried out to study the microstructure of the as-synthesized precursor and product. It has been demonstrated that the as-prepared MgO has a porous hierarchical structure and a high specific surface area (148 m(2) g(-1)). And the MgO sample exhibited super adsorption properties, with maximum adsorption capacity of 2409 mg g(-1) for Congo red, which is the highest reported value. Moreover, the adsorption process of Congo red on porous hierarchical MgO was systematically investigated, which was found to obey the pseudo-second-order rate equation and Langmuir adsorption model.

A new two-dimensional cadmium metal-organic framework: poly[bis(4,7-diphenyl-1,10-phenanthroline)(µ3-5-nitroisophthalato)cadmium(II)].

In the title cadmium metal-organic framework complex, [Cd(C(8)H(3)NO(6))(C(24)H(16)N(2))](n) or [Cd(NIPH)(dpphen)] (NIPH is nitroisophthalate and dpphen is 4,7-diphenyl-1,10-phenanthroline), the unique Cd(II) cation in a general position is coordinated by four carboxy O atoms from three symmetry-related NIPH anions and two N atoms from a dpphen ligand. The Cd(II) cations are bridged by pairs of NIPH anions to generate a dinuclear molecular building block, [Cd(2)N(4)(CO(2)R)(4)], with a Cd···Cd separation of 4.0936 (10) Å. Each such building block is connected to four adjacent dinuclear building blocks by NIPH anions, resulting in a two-dimensional layer framework in the bc plane. The dpphen ligands occupy the space between these layers and are linked by π-π interactions, with a separation of 3.4541 (6) Å between the central aromatic rings of inversion-related dpphen ligands. The thermogravimetric and photoluminescent properties of the complex have also been investigated.