Shared xerophytic genes and their re-use in local adaptation to aridity in the desert plant Gymnocarpos przewalskii.

In order to thrive and survive, plant species need to combine stability in the long term and rapid response to environmental challenges in the short term. The former would be reflected by parallel or convergent adaptation across species, and the latter by pronounced local adaptation among populations of the same species. In the present study, we generated a high-quality genome and re-sequenced 177 individuals for Gymnocarpos przewalskii, an important desert plant species from North-West China, to detect local adaptation. We first focus on ancient adaptation to aridity at the molecular level by comparing the genomic data of 15 species that vary in their ability to withstand aridity. We found that a total of 118 genes were shared across xerophytic species but absent from non-xerophytic species. Of the 65 found in G. przewalskii, 63 were under purifying selection and two under positive selection. We then focused on local adaptation. Up to 20% of the G. przewalskii genome showed signatures of local adaptation to aridity during population divergence. Thirteen of the selected shared xerophytic genes were reused in local adaptation after population differentiation. Hence, only about 20% of the genes shared and specific to xerophytic species and associated with adaptation to aridity were later recruited for local adaptation in G. przewalskii.

Phylogenomics of mulberries (Morus, Moraceae) inferred from plastomes and single copy nuclear genes.

Mulberries (genus Morus), belonging to the order Rosales, family Moraceae, are important woody plants due to their economic values in sericulture, as well as for nutritional benefits and medicinal values. However, the taxonomy and phylogeny of Morus, especially for the Asian species, remains challenging due to its wide geographical distribution, morphological plasticity, and interspecific hybridization. To better understand the evolutionary history of Morus, we combined plastomes and a large-scale nuclear gene analyses to investigate their phylogenetic relationships. We assembled the plastomes and screened 211 single-copy nuclear genes from 13 Morus species and related taxa. The plastomes of Morus species were relatively conserved in terms of genome size, gene content, synteny, IR boundary and codon usage. Using nuclear data, our results elucidated identical topologies based on coalescent and concatenation methods. The genus Morus was supported as monophyletic, with M. notabilis as the first diverging lineage and the two North American Morus species, M. microphylla and M. rubra, as sister to the other Asian species. In the Asian Morus species, interspecific relationships were completely resolved. However, cyto-nuclear discordances and gene tree-species tree conflicts were detected in the phylogenies of Morus, with multiple evidences supporting hybridization/introgression as the main cause of discordances between nuclear and plastid phylogenies, while gene tree-species tree conflicts were mainly caused by ILS.

Phylogenomics and phylogeography of Menispermum (Menispermaceae).

Introduction: Phylogenomics have been widely used to resolve ambiguous and controversial evolutionary relationships among plant species and genera, and the identification of unique indels in plastomes may even help to understand the evolution of some plant families. Menispermum L. (Menispermaceae) consists of three species, M. dauricum DC., M. canadense L., and M. mexicanum Rose, which are disjuncly distributed among East Asia, Eastern North America and Mexico. Taxonomists continue to debate whether M. mexicanum is a distinct species, a variety of M. dauricum, or simply a synonym of M. canadense. To date, no molecular systematics studies have included this doubtful species in phylogenetic analyses. Methods: In this study, we examined phylogenomics and phylogeography of Menispermum across its entire range using 29 whole plastomes of Menispermaceae and 18 ITS1&ITS2 sequences of Menispermeae. We reconstructed interspecific relationships of Menispermum and explored plastome evolution in Menispermaceae, revealing several genomic hotspot regions for the family. Results and discussion: Phylogenetic and network analyses based on whole plastome and ITS1&ITS2 sequences show that Menispermum clusters into two clades with high support values, Clade A (M. dauricum) and Clade B (M. canadense + M. mexicanum). However, M. mexicanum is nested within M. canadense and, as a result, we support that M. mexicanum is a synonym of M. canadense. We also identified important molecular variations in the plastomes of Menispermaceae. Several indels and consequently premature terminations of genes occur in Menispermaceae. A total of 54 regions were identified as the most highly variable plastome regions, with nucleotide diversity (Pi) values > 0.05, including two coding genes (matK, ycf1), four introns (trnK intron, rpl16 intron, rps16 intron, ndhA intron), and 48 intergenic spacer (IGS) regions. Of these, four informative hotspot regions (trnH-psbA, ndhF-rpl32, trnK-rps16, and trnP-psaJ) should be especially useful for future studies of phylogeny, phylogeography and conservation genetics of Menispermaceae.

Phylogenomics, plastome structure and species identification in Mahonia (Berberidaceae).

BACKGROUND: Elucidating the phylogenetic relationships within species-rich genera is essential but challenging, especially when lineages are assumed to have been going through radiation events. Mahonia Nutt. (Berberidaceae) is a genus with cosmopolitan distribution, comprising approximately 100 species, two of which are known as Caulis Mahoniae (M. bealei and M. fortunei) with crucial pharmacological significance in Chinese herbal medicine. Mahonia is a taxonomically challenging genus, and intrageneric phylogenetic relationships still need to be explored using genome data. Universal DNA barcodes and floral morphological attributes have limited discriminatory power in Mahonia. RESULTS: We sequenced 17 representative plastomes and integrated three published plastome data together to conduct comparative and phylogenetic analyses. We found that Mahonia and Berberis share a large IR expansion (~ 12 kb), which is recognized as a typical character of Berberideae. Repeated sequences are revealed in the species of Mahonia, which are valuable for further population genetic studies. Using a comparative plastome analysis, we determined eight hypervariable regions whose discriminative power is comparable to that of the whole plastid genomes. The incongruence of the ITS and the plastome tree topologies may be ascribed to ancestral hybridization events and/or to incomplete lineage sorting. In addition, we suggest that leaf epidermal characters could help to distinguish closely related species in Mahonia. CONCLUSIONS: We propose an integrative approach combining special barcodes and micromorphological traits to circumscribe Mahonia species. The results cast a new light on the development of an integrative method for accurate species circumscription and provide abundant genetic resources for further research on Mahonia.

Comparative and Phylogenetic Analyses of Complete Chloroplast Genomes of Scrophularia incisa Complex (Scrophulariaceae).

The Scrophularia incisa complex is a group of closely related desert and steppe subshrubs that includes S. incisa, S. kiriloviana and S. dentata, which are the only S. sect. Caninae components found in Northwest China. Based on earlier molecular evidence, the species boundaries and phylogenetic relationships within this complex remain poorly resolved. Here, we characterized seven complete chloroplast genomes encompassing the representatives of the three taxa in the complex and one closely related species, S. integrifolia, as well as three other species of Scrophularia. Comparative genomic analyses indicated that the genomic structure, gene order and content were highly conserved among these eleven plastomes. Highly variable plastid regions and simple sequence repeats (SSRs) were identified. The robust and consistent phylogenetic relationships of the S. incisa complex were firstly constructed based on a total of 26 plastid genomes from Scrophulariaceae. Within the monophyletic complex, a S. kiriloviana individual from Pamirs Plateau was identified as the earliest diverging clade, followed by S. dentata from Tibet, while the remaining individuals of S. kiriloviana from the Tianshan Mountains and S. incisa from Qinghai-Gansu were clustered into sister clades. Our results evidently demonstrate the capability of plastid genomes to improve phylogenetic resolution and species delimitation, particularly among closely related species, and will promote the understanding of plastome evolution in Scrophularia.

Plio-Pleistocene climatic change drives allopatric speciation and population divergence within the Scrophularia incisa complex (Scrophulariaceae) of desert and steppe subshrubs in Northwest China.

Numerous temperate plants and animals on the Qinghai-Tibet Plateau (QTP) are hypothesized to have differentiated due to vicariant allopatric speciation associated with the geologic uplifts. However, this hypothesis has rarely been tested through a phylogeographic study of relative species in a broader geographic context, including the QTP, Tianshan Mountains, Mongolian Plateau, and surrounding regions. To understand the speciation and diversification process of plants across this wide area, phylogeographic analysis were examined from Scrophularia incisa and two other closely relative species comprising S. kiriloviana and S. dentata. Thirty-two populations of the three close relatives were genotyped using chloroplast DNA fragments and nuclear microsatellite loci to assess population structure and diversity, supplemented by phylogenetic dating, ancestral area reconstructions and species distribution modelings, as well as niche identity tests. Our chloroplast DNA (cpDNA) phylogeny showed that this monophyletic group of desert and steppe semi-shrub is derived from a Middle Pliocene ancestor of the Central Asia. Lineages in Central Asia vs. China diverged through climate/tectonic-induced vicariance during Middle Pliocene. Genetic and ENM data in conjunction with niche differentiation analyses support that the divergence of S. incisa, S. dentata and S. kiriloviana in China lineage proceeded through allopatric speciation, might triggered by early Pleistocene climate change of increase of aridification and enlargement of deserts, while subsequent climate-induced cycles of range contractions/expansions enhanced the geographical isolation and habit fragmentation of these taxa. These findings highlight the importance of the Plio-Pleistocene climate change in shaping genetic diversity and driving speciation in temperate steppes and deserts of Northwestern China.

Spatial evaluation of the ecological value importance of national park in Yarlung Tsangpo Grand Canyon.

The Yarlung Tsangpo Grand Canyon (YTGC) region is one of China's vital gene banks of mountain biological species resources. It is also an experimental site for biologists worldwide to study how organisms differentiate in the exceptional environment of the plateau. Evaluating the importance of the ecological value and identifying extremely important regions to national parks to implement the strictest conservation is significant to protecting and preserving global biodiversity. YTGC as the study area, and a comprehensive evaluation model conformed to ecological value attributes was established: (i) evaluation of ecosystem service function, including water retention, soil and water conservation and biodiversity maintenance; (ii) evaluation of ecological vulnerability, including soil erosion and geological disasters; (iii) evaluation of ecological conservation, including Important Bird and Biodiversity Areas (IBAs), Global 200 Ecoregions (G200), Biodiversity Hotspots (BH), Endemic Bird Areas (EBAs) and Priority Areas for Biodiversity Conservation in China (PABCC). Identifying as extremely important, important, and general important regions, then mosaicked with the maximum value. The results show: first, the extremely important regions of ecosystem service are about 30,242.90 km2 (45.64%), distributed in most regions flowing southwest along the Yarlung Zangbo River. Second, the ecological vulnerability regions are about 26,561.65 km2 (40.06%), concentrated and contiguously distributed in the valley regions along the Yarlung Zangbo River and the high-altitude glacier-covered regions. Third, the extremely important regions for ecological conservation are mainly distributed in Milin County (39.86%) and Medog County (36.33%), which also presents a clustered distribution in the highly high mountains with apparent differentiation along the Yarlung Zangbo River valley in Milin County and the vertical natural belt centered on the Namjagbarwa and the Galabai Leifeng. Finally, we proposed that the integrated extremely important regions of ecological value should be divided into national parks for strict conservation; at the same time, it is also a reference for considering the construction of biodiversity conservation corridors when roads pass through the extremely important regions. This study presents a reliable and integrative method for effectively identifying conservation priority areas at small-medium scales, which can be applied to other PAs planning and management.

Spatial Distribution Characteristics of the Rural Tourism Villages in the Qinghai-Tibetan Plateau and Its Influencing Factors.

The development of rural tourism (RT) has great significance in reducing poverty and achieving rural vitalization. Qinghai-Tibetan Plateau (QTP) is a depressed area with rich RT resources due to its unspoiled nature and diverse culture. For future sustainable development of RT in QTP, this paper analyzes the spatial distribution characteristics and its influencing factors of RT villages using various spatial analysis methods, such as nearest neighbor index, kernel density estimation, vector buffer analysis, and geographic detectors. The results show the following. First, the RT villages present an agglomeration distribution tendency dense in the southeast and spare in the northwest. The inter-county imbalance distribution feature is obvious and four relatively high-density zones have been formed. Second, the RT villages have significant positive spatial autocorrelation, and the area of cold spots is larger and of hot spots is smaller. Third, the RT villages are mainly distributed with favorable topographic and climate conditions, near the road and water, around the city, and close to tourism resources. Fourth, the spatial distribution is the result of multifactor interactions. Socio-economic and tourism resource are the dominant factor in the mechanism network. Fifth, based on the above conclusions this study provides scientific suggestions for the sustainable development of the RT industry.

Plastid Phylogenomics and Plastome Evolution of Nandinoideae (Berberidaceae).

Subfamily Nandinoideae Heintze (Berberidaceae), comprising four genera and ca. 19 species, is disjunctively distributed in eastern North America vs. Eurasia (eastern Asia, Central Asia, Middle East, and southeastern Europe), and represents an ideal taxon to explore plastid phylogenomics and plastome evolution in Berberidaceae. Many species of this subfamily have been listed as national or international rare and endangered plants. In this study, we sequenced and assembled 20 complete plastomes, representing three genera and 13 species of Nandinoideae. Together with six plastomes from GenBank, a total of 26 plastomes, representing all four genera and 16 species of Nandinoideae, were used for comparative genomic and phylogenomic analyses. These plastomes showed significant differences in overall size (156,626-161,406 bp), which is mainly due to the expansion in inverted repeat (IR) regions and/or insertion/deletion (indel) events in intergenic spacer (IGS) regions. A 75-bp deletion in the ndhF gene occurred in Leontice and Gymnospermium when compared with Nandina and Caulophyllum. We found a severe truncation at the 5' end of ycf1 in three G. altaicum plastomes, and a premature termination of ropC1 in G. microrrhynchum. Our phylogenomic results support the topology of {Nandina, [Caulophyllum, (Leontice, Gymnospermium)]}. Within the core genus Gymnospermium, we identified G. microrrhynchum from northeastern Asia (Clade A) as the earliest diverging species, followed by G. kiangnanense from eastern China (Clade B), while the rest species clustered into the two sister clades (C and D). Clade C included three species from West Tianshan (G. albertii, G. darwasicum, G. vitellinum). Clade D consisted of G. altaicum from northern Central Asia, plus one species from the Caucasus Mountains (G. smirnovii) and three from southeastern Europe (G. odessanum, G. peloponnesiacum, G. scipetarum). Overall, we identified 21 highly variable plastome regions, including two coding genes (rpl22, ycf1) and 19 intergenic spacer (IGS) regions, all with nucleotide diversity (Pi) values > 0.02. These molecular markers should serve as powerful tools (including DNA barcodes) for future phylogenetic, phylogeographic and conservation genetic studies.

Bibliometric Analysis and Literature Review of Tourism Destination Resilience Research.

The application of resilience thinking to tourism destination research is a new perspective on sustainable tourism and has gradually become a popular research topic. Some literature has been conducted on tourism destination resilience, but there has not been a comprehensive review and analysis of the whole field. This study was based on the literature from 2000 to 2021 in the Web of Science core collection database. The collaboration analysis, literature co-citation analysis, keyword co-occurrence, burst detection analysis in CiteSpace, and qualitative analysis were adopted to conduct a holistic tourism destination resilience research review. The results indicated that the United States, Australia, China, and the United Kingdom were the primary countries involved in tourism destination resilience research. Five hot research themes were obtained. (1) concept and connotation of tourism destination resilience, (2) drivers of tourism destination resilience, (3) sustainable management framework and practices, (4) perception of tourism destination resilience, and (5) the resilience of the tourism community. Furthermore, four research gaps and future directions were proposed in this study, including the theoretical framework of tourism destination resilience, assessment of tourism destination resilience, sustainable management and resilience, and application of advanced technology in tourism destination resilience. This study assists researchers in understanding the development and future research directions in tourism destination resilience research.

Evaluation of Potential for Nature-Based Recreation in the Qinghai-Tibet Plateau: A Spatial-Temporal Perspective.

Nature-based recreation (NBR) is an important cultural ecosystem service providing human well-being from natural environments. As the most concentrated and high-quality wilderness in China, the Qinghai-Tibet Plateau (QTP) has unique advantages for NBR. In this study, we designed an integrated nature-based recreation potential index (INRPI) based on four aspects: nature-based recreation resources, landscape attractiveness, recreation comfort and opportunity, and recreation reception ability. A combination of the analytic hierarchy process (AHP) and entropy evaluation method was adopted to assess the NBR potential in the QTP from 2000 to 2020. The research shows that: (i) The INRPI for the QTP decreases gradually from southeast to northwest and increases slightly from 2000 to 2020. (ii) The INRPI displays a pronounced difference on either side of the Qilian-Gyirong line. The areas with very high and high potentials mainly distributed in the southeast of the line, while areas with very low and low potentials distributed in the northwest. (iii) The construction of protected areas effectively improves NBR potential. Areas of INRPI at diverse levels within protected areas obviously increased in 2020. (iv) Increasing altitude has a notable effect on INRPI, and 3000 m is a critical dividing line for the NBR in the QTP. These findings can contribute to decision-makers in guiding rational use and spatial planning of natural land and promoting sustainable recreational development.

Analysis of spatial patterns and driving factors of provincial tourism demand in China.

Modeling and forecasting tourism demand across destinations has become a priority in tourism research. Most tourism demand studies rely on annual statistics with small sample sizes and lack research on spatial heterogeneity and drivers of tourism demand. This study proposes a new framework for measuring inter-provincial tourism demand's spatiotemporal distribution using search engine indices based on a geographic perspective. A combination of spatial autocorrelation and Geodetector is utilized to recognize the spatiotemporal distribution patterns of tourism demand in 2011 and 2018 in 31 provinces of mainland China and detect its driving mechanisms. The results reveal that the spatial distribution of tourism demand manifests a vital stratification phenomenon with significant spatial aggregation in the southwest and northeast of China. Traffic conditions, social-economic development level, and physical conditions compose a constant and robust interaction network, which dominates the spatial distribution of tourism demand in different development stages through different interactions.

Identification of Priority Conservation Areas for Natural Heritage Sites Integrating Landscape Ecological Risks and Ecosystem Services: A Case Study in the Bogda, China.

The conservation of World Natural Heritage Sites has become a global concern. The identification of priority conservation areas can preserve the value of heritage sites while promoting sustainable development, which is important for balancing the conservation and development of heritage sites. This paper proposes an integrated framework for the identification of priority conservation areas for natural heritage sites based on landscape ecological risks (LERs) and ecosystem services (ESs), taking the Bogda heritage site in Xinjiang, China as a case study. The innovative approach combined the natural and cultural elements of natural heritage sites and included the following steps: (1) the LER index, Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and questionnaire method were adopted to assess the LERs and ESs of Bogda heritage sites during 1990-2018; (2) ordered weighted averaging (OWA) was used to identify conservation priorities by weighing LERs and ESs; and (3) the optimal priority conservation area was determined by comparing the conservation efficiencies under different scenarios. The results revealed that the LER, carbon storage (CS), habitat quality (HQ), aesthetic value (AV), and recreational value (RV) showed significant spatiotemporal variation. The most suitable priority conservation area was located at the central forestlands and high-coverage grasslands, with conservation efficiencies of 1.16, 2.91, 1.96, 1.03, and 1.21 for LER, CS, HQ, AV, and RV, respectively. Our study demonstrated that integrating LERs and ESs is a comprehensive and effective approach to identifying conservation priorities for heritage sites. The results can provide decision support for the conservation of the Bogda heritage site and a methodological reference for identifying conservation priorities for natural heritage sites. Furthermore, this study is also an effective application of LERs and ESs in identifying priority conservation areas.

Can Tourism Development Make Cities More Livable? Investigating 40 Cities in China.

The field of rapid urbanization has recently paid more attention to the relationship between tourism development and liveable city construction. Previous studies have mainly focused on the experiences of tourists in tourist cities and seldom paid attention to the perceptions of local residents. Based on survey data of nearly 10,000 permanent residents in 40 key tourist cities in China, this study uses a multilevel model to quantitatively analyse the natural environment characteristics, sociocultural environment characteristics and comprehensive attraction of tourism in different tourist cities to explore their impact on urban liveability satisfaction. Results show that the developed tourist cities do not exactly correspond to the cities with a high liveability evaluation. The objective evaluation of both the natural environment and the sociocultural environment has an important influence on the liveability of cities, but the influence of the natural environment is stronger than that of the sociocultural environment. An intermediary effect exists in the subjective evaluation of the natural environment and environments for liveability perception. Simultaneously, residents' liveability satisfaction varies according to their age, education level, annual household income and other social and economic conditions. These findings provide insights for developing countries to further improve residents' living quality and urban construction under the condition of the rapid development of tourism.

Characterization of Four Copper Materials for Application as Reference Materials for High Precision Copper Isotope Analysis by Laser Ablation Inductively Coupled Plasma Multi-Collector Mass Spectrometry.

Laser ablation inductively coupled plasma multi-collector mass spectrometry (LA-MC-ICP-MS) allows rapid, in situ, highly precise measurements of Cu isotope ratios of native Cu and Cu-bearing minerals. However, the National Institute of Standards and Technology Cu-metal isotope standard NIST SRM976 that is commonly used to calibrate LA-MC-ICP-MS Cu isotope measurements of native Cu is no longer available. We have investigated the suitability of four Cu metal materials, SSC-1, SSC-3 and SSC-4 (cathode Cu metal rods) and CUPD-1 (Cu anode sawings), originally developed by the Canada Centre for Mineral and Energy Technology (CANMET) as certified reference materials for trace element analysis, as Cu isotope reference materials for LA-MC-ICP-MS analysis and solution nebulization (SN) of Cu. The Cu isotopic composition and homogeneity of these four materials were characterised by SN- and LA-MC-ICP-MS, and are reported for the first time. The bulk Cu isotopic compositions, expressed as δ65CuSRM976 in per mil (‰) relative to NIST SRM976 with combined uncertainties (U, k = 2), of SSC-1, SSC-3 and SSC-4, determined utilizing SN-MC-ICP-MS, are identical within analytical uncertainty at 0.03 ± 0.07‰ (n = 29), 0.04 ± 0.04‰ (n = 28), and 0.05 ± 0.08‰ (n = 29), respectively; the composition of CUPD-1 is 2.14 ± 0.08‰ (n = 28). The compositions are 0.01 ± 0.07‰ (n = 29), 0.04 ± 0.06‰ (n = 29), 0.03 ± 0.06‰ (n = 28) and 2.15 ± 0.06‰ (n = 28), respectively, relative to the European Reference Material ERM®-AE633 Cu isotope standard. The Cu isotope homogeneity of the four new reference materials was assessed by determining whether multiple individual in situ Cu isotope measurements made by LA-MC-ICP-MS analysis (43 µm spot size), using each of the other three reference materials as a calibrator, approximate a single normal distribution. We also investigate whether there are statistically significant differences between the mean δ65Cu values of three independent data sets for each of the Cu isotope reference materials using one-way analysis of variance (ANOVA). Normality tests (graphical assessment of normal distribution quantile-quantile plots, and the Shapiro-Wilk, Jarque-Bera and reduced chi-squared statistic tests) show that: 1) the Cu isotope data acquired on SSC-1, SSC-3, SSC-4 and CUPD-1 do not depart significantly from a normal distribution, 2) the scatter of the Cu isotope data is due to analytical uncertainty with 95% confidence, and 3) there are no other significant sources of scatter; e.g. heterogeneity of the reference materials. The results of one-way ANOVA reveal that the mean difference of the δ65Cu value for each of the reference materials SSC-1, SSC-3, SSC-4 and CUPD-1 is statistically not significant at the 0.05 level. The mean δ65CuSRM976 values with combined uncertainties (U, k = 2) of SSC-1, SSC-3, SSC-4 and CUPD-1, determined by LA-MC-ICP-MS using each of the other three reference materials as a calibration standard, are 0.03 ± 0.09‰ (n = 132), 0.05 ± 0.09‰ (n = 154), 0.03 ± 0.09‰ (n = 144) and 2.14 ± 0.10‰ (n = 106), respectively. These values are in agreement with those determined by SN-MC-ICP-MS analysis at the 95% confidence level and have excellent precision (2 s.d. ≤ 0.10‰). These results suggest that SSC-1, SSC-3, SSC-4 and CUPD-1 can be considered isotopically homogeneous at a spatial resolution of 43 µm, and they are suitable reference materials for calibration and quality control of in situ and solution nebulization Cu isotope analyses of Cu.

Suitability evaluation for mountain-based adventure tourism: A case study of Xinjiang Tianshan, China.

In recent years, there has been considerable growth in the provision of and demand for adventure tourism; however, research that examines the resources regarding adventure tourism is limited. A spatial suitability evaluation system for mountain-based adventure tourism (MBAT) was developed via the integration of the AHP-Delphi technique. The evaluation system parameters included resource conditions, difficulty levels, safety conditions, and ecological sensitivity. Furthermore, each parameter contained several indicators that can be quantified and visualised in ArcGIS. The results showed that suitable areas for professional adventure tourism in Xinjiang Tianshan include the Kurdening and Tomur regions, and the those for adventure tourism include the Tianshan Tianchi lake. Furthermore, suitable areas for experiential adventure tourism include the Tianshan Tianchi lake, Tianshan Grand Canyon, Jiangbulak, East Tianshan, Tuohurasu scenic area, and the Gongliu wild fruit forest, while those for mass adventure tourism include large areas in the middle and low altitude range of Tianshan. The methods and results proposed in this paper are expected to be significant for planning adventure tourism and can be helpful for mountain communities when choosing regions to develop for adventure tourism, formulating tourism development strategies, increasing tourism opportunities, and thus improving regional competitiveness.

Corneal differences between healthy and subclinical patients assessed using two diferente corneal tomographers / Diferenças entre as córneas de pacientes saudáveis e pacientes subclínicos avaliados com dois tipos de tomógrafos de córnea

ABSTRACT Purpose: To analyze subclinical keratoconus topography indexes using Pentacam and Orbscan-II measurements to identify evidences for seeking sensitive indexes to screen and diagnose subclinical keratoconus. Methods: Fifty healthy participants (50 eyes) and 40 patients with subclinical keratoconus (40 eyes) were included. Seven common parameters including corneal thickness at the thinnest point; minimum curvature of the front surface (minimum simulated keratometry value, SimK's Min); maximum curvature of the front surface (maximum simulated keratometry value, SimK's Max); the frontal corneal surface best-fit spherical radius of the curvature; the back corneal surface best-fit spherical radius of curvature; the anterior corneal surface height (anterior Diff value); and the posterior corneal surface height (posterior Diff value) measured by Pentacam and Orbscan-II between normal and subclinical keratoconus eyes were compared. Results: Statistical differences between the healthy and subclinical keratoconus groups (p<0.01) were found in all corneal parameters measured using both devices. Differences in the minimum curvature of the front surface (SimK's Min), thinnest point, anterior Diff value, and posterior Diff value were significant between Pentacam and Orbscan-II in the subclinical keratoconus group (p<0.05). Conclusion: The findings of this study identify the differences between normal and subclinical keratoconus eyes at the minimum curvature of the front surface, maximum curvature of the front surface, frontal corneal surface best-fit spherical radius of curvature, back corneal surface best-fit spherical radius of curvature, Anterior Diff value, and Posterior Diff value measures using Orbscan II and Pentacam that can help eye care practitioners clinically diagnose subclinical keratoconus.

RESUMO Objetivo: Analisar os índices subclínicos de to pografia de ceratocone utilizando as medidas feitas com Pentacam e com Orbscan-II para identificar evidências para a busca de índices sensíveis para triagem e diagnóstico de ceratocone subclínico. Métodos: Cinquenta participantes saudáveis (50 olhos) e 40 pacientes com ceratocone subclínico (40 olhos) foram incluídos. Sete parâmetros comuns, incluindo a espessura da córnea no ponto mais fino; a curvatura mínima da superfície frontal (valor mínimo da ceratometria simulada, Min de SimK); a curvatura máxima da superfície frontal (valor máximo da ceratometria simulada, Max de SimK); a superfície frontal e a superfície posterior da córnea de melhor ajuste ao raio da curvatura, a altura da superfície anterior da córnea (valor Diff anterior) e a altura da superfície corneana posterior (valor Diff posterior) medidos pelo Pentacam e pelo Orbscan-II entre os olhos normais e com ceratocone subclínico foram comparados. Resultados: As diferenças estatísticas entre os grupos saudável e com ceratocone subclínico (p<0,01) foram encontradas em todos os parâmetros corneanos medidos usando ambos os dispositivos. Diferenças na curvatura mínima da superfície frontal (Min de SimK) no ponto mais fino, no valor Diff anterior e no valor Diff posterior foram significativas entre Pentacam e Orbscan-II no grupo com ceratocone subclínico (p<0,05). Conclusão: Os achados deste estudo identificam as diferenças entre olhos normais e com ceratocone subclínico para a curvatura mínima da superfície frontal, a curvatura máxima da superfície frontal, a superfície corneana frontal e a superfície corneana posterior de melhor ajuste ao raio esférico da curvatura e as medidas de Diff anterior e posterior usando Orbscan II e o Pentacam que podem auxiliar os profissionais de oftalmologia a diagnosticar clinicamente o ceratocone subclínico.

Plant production decreases whereas nutrients concentration increases in response to the decrease of mowing stubble height.

Mowing is a common practice in grassland management. It removes the majority of current year's aboveground plant biomass and thus substantial amounts of nutrients residing in plant tissues. The responses of plant aboveground biomass and nutrients to mowing stubble height is of great importance for developing sustainable mowing regimes, however, they are not well understood. We studied the effects of 4-year annual mowing at different height on plant aboveground biomass, plant N, P and N:P ratio, and soil nutrients in an Inner Mongolian steppe. Six stubble heights were set respectively at 14 cm (M14), 12 cm (M12), 10 cm (M10), 8 cm (M8), 6 cm (M6) and less than 0.3 cm (M0) height to ground surface. A no-mowing treatment (CK) was also included, making seven treatments. The results show that plant biomass production increased under light mowing (stubble height  > 12 cm) but decreased under heavy mowing (stubble height  < 6 cm), and the optimal stubble height for sustainable mowing was 6-12 cm. Plant N and P concentrations increased with mowing intensity (i.e. with the decrease of mowing stubble height). Plant N:P ratio decreased for some species, but no a directional change was detected in plant N:P ratio at the community level, nor in soil organic carbon and nutrient concentrations across the stubble height treatments. Our results indicate that plant biomass and N & P respond quickly to mowing height, whereas the response of soil chemical properties is insignificant over the 4-year period. To elucidate variation of species compensatory growth along mowing intensity gradient and the mutual feedback mechanism of soil-plant in mowing grassland, long-term study at permanent sites with changing stubble heights should be strengthened.

Corneal differences between healthy and subclinical patients assessed using two diferente corneal tomographers.

PURPOSE: To analyze subclinical keratoconus topography indexes using Pentacam and Orbscan-II measurements to identify evidences for seeking sensitive indexes to screen and diagnose subclinical keratoconus. METHODS: Fifty healthy participants (50 eyes) and 40 patients with subclinical keratoconus (40 eyes) were included. Seven common parameters including corneal thickness at the thinnest point; minimum curvature of the front surface (minimum simulated keratometry value, SimK's Min); maximum curvature of the front surface (maximum simulated keratometry value, SimK's Max); the frontal corneal surface best-fit spherical radius of the curvature; the back corneal surface best-fit spherical radius of curvature; the anterior corneal surface height (anterior Diff value); and the posterior corneal surface height (posterior Diff value) measured by Pentacam and Orbscan-II between normal and subclinical keratoconus eyes were compared. RESULTS: Statistical differences between the healthy and subclinical keratoconus groups (p<0.01) were found in all corneal parameters measured using both devices. Differences in the minimum curvature of the front surface (SimK's Min), thinnest point, anterior Diff value, and posterior Diff value were significant between Pentacam and Orbscan-II in the subclinical keratoconus group (p<0.05). CONCLUSION: The findings of this study identify the differences between normal and subclinical keratoconus eyes at the minimum curvature of the front surface, maximum curvature of the front surface, frontal corneal surface best-fit spherical radius of curvature, back corneal surface best-fit spherical radius of curvature, Anterior Diff value, and Posterior Diff value measures using Orbscan II and Pentacam that can help eye care practitioners clinically diagnose subclinical keratoconus.

Evaluation for landscape aesthetic value of the Natural World Heritage Site.

The landscape aesthetic value (LAV) is one essential component of outstanding universal value (OUV) for a Natural World Heritage Site (NWHS). In the identification of LAV, there is the subjectivity of methodology suggested by IUCN in the operation manual, and the expert-led evaluation is insufficient for reflecting all observers' opinions. This study focuses on establishing a universal system combining the subjectivity and objectivity, the experts' and the public's opinions to evaluate the LAV of an NWHS. We used the NWHS criteria, the ecological environment, and the viewing experience as established indicators; nine metrics were applied as corresponding layers respectively to map and give a final spatial evaluation based on the ArcGIS overlay analysis with their comprehensive weights from 3 groups of decision makers. In order to verify the rationality of our model, the LAV of a case study in Bayanbulak of NWHS Xinjiang Tianshan has been evaluated. It is demonstrated that central region of Bayanbulak with unique landscape that taking rivers, lakes, and swamps as base interlacing with wetland meadows has particularly high LAV; it basically shows a concentric circle-like distribution feature that LAV decreases from inside to outside and is consistent with practical protection status. This study responds to the UNESCO's request to monitor and evaluate the OUV of the NWHS; we believe results can provide a useful reference for the planning and decision-making of relevant scenic spots.