What makes a good phorophyte? Predicting occupancy, species richness and abundance of vascular epiphytes in a lowland seasonal tropical forest

peer reviewedEpiphytes typically exhibit clustered distribution patterns, but predicting the spatial variation of their distribution at fine scales has long been a challenge. Taking advantage of a canopy crane giving access to 1.1 ha of lowland seasonal rainforest in Yunnan (China), we assess here which factors promote the probability that a given tree hosts epiphytes, and the variation of species richness and abundance of epiphytic spermatophytes and ferns among trees. Variation in epiphyte species richness as a function of host tree size, characteristics of its surrounding environment, topography and microclimatic conditions, were analyzed by Random Forest. Epiphytic spermatophytes and ferns occupied 2.3 and 10.8% of the available host trees, respectively. Significant models predicting which trees are more likely to host epiphytes than others were obtained, indicating that host tree characteristics and their local environment play a significant role in determining which host tree is most likely to be colonized. These models, as well as models for species richness and abundance, however, exhibited a moderate to low accuracy (r2 0.28 and 0.24 and of 0.12 and 0.14 for spermatophyte and fern richness and abundance, respectively). The best predictor of the presence of epiphytes on a tree, of its epiphytic species richness and abundance, was its DBH. In ferns, however, two peaks of species richness were observed, representing shade-loving ferns on small trees and sun-loving ferns on large trees. Microclimatic conditions and light intensity were the second best factor accounting for variation in species richness and abundance among trees. The contribution of liana infestation, host tree identity, and characteristics of neighboring trees were marginal. Our inclusion of a large number of host-tree characteristics and their local environment did not allow for an apparent improvement of model accuracy over studies with a more limited number of predictors, pointing to the role of chance upon tree colonization. Our results confirm the utmost importance of large trees with emergent canopies for the conservation of the epiphytic flora, but also indicate that epiphytic diversity assessments in tropical forests must also include small understorey trees, which should be further considered for conservation. The importance of the micro-climatic conditions that prevail at the level of each individual host tree further points to the necessity of maintaining a buffer zone around large host trees targeted for conservation

Genetic Variation in Quercus acutissima Carruth., in Traditional Japanese Rural Forests and Agricultural Landscapes, Revealed by Chloroplast Microsatellite Markers

uercus acutissima Carruth. is an economically important species that has long been cultivated in Japan, so is a valuable subject for investigating the impact of human activities on genetic variation in trees. In total, 2152 samples from 18 naturally regenerated populations and 28 planted populations in Japan and 13 populations from the northeastern part of Eurasia, near Japan, were analyzed using six maternally inherited chloroplast (cpDNA) simple sequence repeat (SSR) markers. Although 23 haplotypes were detected in total, both the Japanese natural and artificial populations exhibited much lower genetic diversity than the continental populations. The level of genetic differentiation among natural populations in Japan was also much lower (G’ST = 0.261) than that on the continent (G’ST = 0.856). These results suggest that human activities, such as historical seed transfer, have reduced genetic diversity within and among populations and resulted in a homogeneous genetic structure in Japan. The genetic characteristics of natural and artificial populations of Quercus acutissima in Japan are almost the same and it is likely that most of the natural populations are thought to have originated from individuals that escaped from plantations

Observation of Quantum Griffiths Singularity and Ferromagnetism at Superconducting LaAlO3/SrTiO3(110) Interface

Diverse phenomena emerge at the interface between band insulators LaAlO3 and SrTiO3, such as superconductivity and ferromagnetism, showing an opportunity for potential applications as well as bringing fundamental research interests. Particularly, the two-dimensional electron gas formed at LaAlO3/SrTiO3 interface offers an appealing platform for quantum phase transition from a superconductor to a weakly localized metal. Here we report the superconductor-metal transition in superconducting two-dimensional electron gas formed at LaAlO3/SrTiO3(110) interface driven by a perpendicular magnetic field. Interestingly, when approaching the quantum critical point, the dynamic critical exponent is not a constant but a diverging value, which is a direct evidence of quantum Griffiths singularity raised from quenched disorder at ultralow temperatures. Furthermore, the hysteretic property of magnetoresistance was firstly observed at LaAlO3/SrTiO3(110) interfaces, which suggests potential coexistence of superconductivity and ferromagnetism

Gold-Catalyzed Tandem Cycloisomerizationand Dimerization of Chiral Homopropargyl Sulfonamides

We are grateful for the financial support from the National Natural Science Foundation of China (No. 21102119 and 21272191), the Natural Science Foundation of Fujian Province of China (No. 2012J01051), NFFTBS (No. J1210014), and PCSIRT. We also thank Professor Dr. Liming Zhang (University of California Santa Barbara) for the helpful discussions

Patterns of linkage disequilibrium and haplotype distribution in disease candidate genes

BACKGROUND: The adequacy of association studies for complex diseases depends critically on the existence of linkage disequilibrium (LD) between functional alleles and surrounding SNP markers. RESULTS: We examined the patterns of LD and haplotype distribution in eight candidate genes for osteoporosis and/or obesity using 31 SNPs in 1,873 subjects. These eight genes are apolipoprotein E (APOE), type I collagen α1 (COL1A1), estrogen receptor-α (ER-α), leptin receptor (LEPR), parathyroid hormone (PTH)/PTH-related peptide receptor type 1 (PTHR1), transforming growth factor-β1 (TGF-β1), uncoupling protein 3 (UCP3), and vitamin D (1,25-dihydroxyvitamin D(3)) receptor (VDR). Yin yang haplotypes, two high-frequency haplotypes composed of completely mismatching SNP alleles, were examined. To quantify LD patterns, two common measures of LD, D' and r(2), were calculated for the SNPs within the genes. The haplotype distribution varied in the different genes. Yin yang haplotypes were observed only in PTHR1 and UCP3. D' ranged from 0.020 to 1.000 with the average of 0.475, whereas the average r(2 )was 0.158 (ranging from 0.000 to 0.883). A decay of LD was observed as the intermarker distance increased, however, there was a great difference in LD characteristics of different genes or even in different regions within gene. CONCLUSION: The differences in haplotype distributions and LD patterns among the genes underscore the importance of characterizing genomic regions of interest prior to association studies

Current limitations of SNP data from the public domain for studies of complex disorders: a test for ten candidate genes for obesity and osteoporosis

BACKGROUND: Public SNP databases are frequently used to choose SNPs for candidate genes in the association and linkage studies of complex disorders. However, their utility for such studies of diseases with ethnic-dependent background has never been evaluated. RESULTS: To estimate the accuracy and completeness of SNP public databases, we analyzed the allele frequencies of 41 SNPs in 10 candidate genes for obesity and/or osteoporosis in a large American-Caucasian sample (1,873 individuals from 405 nuclear families) by PCR-invader assay. We compared our results with those from the databases and other published studies. Of the 41 SNPs, 8 were monomorphic in our sample. Twelve were reported for the first time for Caucasians and the other 29 SNPs in our sample essentially confirmed the respective allele frequencies for Caucasians in the databases and previous studies. The comparison of our data with other ethnic groups showed significant differentiation between the three major world ethnic groups at some SNPs (Caucasians and Africans differed at 3 of the 18 shared SNPs, and Caucasians and Asians differed at 13 of the 22 shared SNPs). This genetic differentiation may have an important implication for studying the well-known ethnic differences in the prevalence of obesity and osteoporosis, and complex disorders in general. CONCLUSION: A comparative analysis of the SNP data of the candidate genes obtained in the present study, as well as those retrieved from the public domain, suggests that the databases may currently have serious limitations for studying complex disorders with an ethnic-dependent background due to the incomplete and uneven representation of the candidate SNPs in the databases for the major ethnic groups. This conclusion attests to the imperative necessity of large-scale and accurate characterization of these SNPs in different ethnic groups

A Binary-Medium Constitutive Model for Artificially Structured Soils Based on the Disturbed State Concept and Homogenization Theory

Triaxial compression tests were carried out on artificially structured soil samples at confining pressures of 25, 37.5, 50, 100, 200, and 400 kPa. A binary-medium constitutive model for artificially structured soils is proposed based on the experimental results, the disturbed state concept (DSC), and homogenization theory. A new constitutive model for artificially structured soils was formulated by regarding the structured soils as a binary medium consisting of bonded blocks and weakened bands. The bonded blocks are idealized as bonded elements whose deformation properties are described by elastic materials, and the weakened bands are idealized as frictional elements whose deformation properties are described by the Lade-Duncan model. By introducing the structural parameters of breakage ratio and local strain coefficient, the nonuniform distribution of stress and strain within a representative volume element can be given based on the homogenization theory of heterogeneous materials. The methods for determination of the model parameters are given on the basis of experimental results. Comparisons of predictions with experimental data demonstrate that the new model provides satisfactory qualitative and quantitative modeling of many important features of artificially structured soils

Sustainable forest management beyond the timber-oriented status quo : transitioning to co-production of timber and non-wood forest products—a global perspective

PURPOSE OF REVIEW : This review provides perspectives and insights of forest researchers from four continents representing a range of geo-regions, with examples from diverse and dynamic use of forest products that are undervalued and often misrepresented. A comprehensive discussion of the subject provides special attention to property, tenancy, public goods and access rights to nonwood forest products (NWFP), seen as forest ecosystem services in a framework for forest management decisions. The overall purpose is to provide a logical argument for transitioning to sustainable management of forests for timber and NWFP. RECENT FINDINGS : Multifunctional ecosystem-based approaches are transforming our understanding of forests. The prevailing economic relevance of NWFP for trade and sustenance requires their operative integration into forest management. Integration of NWFP will shift a traditional timber-oriented management paradigm towards an inclusive ecosystem forest management approach. We show that the impact of NWFP resources on livelihoods provides multiple benefits to all sectors of global society. Policy and property rights affect the availability and sustainability of the resource, while regulations, restrictions and prohibitions target the sustainable harvest of NWFP under growing demand. Official reporting of production volumes of NWFP is sparse, erratic or inaccurate due to a complex system that is opaque and with inadequately understood value chains, yet research is underway to better understand all NWFP sectors. SUMMARY : A shift from command-and-control forest management to broader governance schemes is observed, yet despite a growing awareness of their importance, NWFP and their potential for a bio-based economy require more research. A conceptual framework for transitioning to sustainable co-production management of timber and NWFP is presented. Such a transition is needed to ensure long-term forest security, health and resilience.Open Access funding provided by Projekt DEAL. The authors thank the European Commission for support of their research by the past European FP7 project StarTree, grant agreement 311919, the COSTAction FP1203 on NWFPs, as well as the ongoing H2020 Thematic network INCREDIBLE, grant agreement 774632. The BMBF funded SPACES2 project ASAP, grant agreement 01LL1803A, and National Key R&D Program of China grant agreement 2017YFD0600600.https://www.springer.com/journal/40725am2020Plant Production and Soil Scienc

The LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap I. The Spectroscopic Redshift Catalog

We present a spectroscopic redshift catalog from the LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap (SGC), which is designed to observe all sources (Galactic and extra-galactic) by using repeating observations with a limiting magnitude of $r=18.1~mag$ in two $20~deg^2$ fields. The project is mainly focusing on the completeness of LAMOST ExtraGAlactic Surveys (LEGAS) in the SGC, the deficiencies of source selection methods and the basic performance parameters of LAMOST telescope. In both fields, more than 95% of galaxies have been observed. A post-processing has been applied to LAMOST 1D spectrum to remove the majority of remaining sky background residuals. More than 10,000 spectra have been visually inspected to measure the redshift by using combinations of different emission/absorption features with uncertainty of $\sigma_{z}/(1+z)<0.001$. In total, there are 1528 redshifts (623 absorption and 905 emission line galaxies) in Field A and 1570 redshifts (569 absorption and 1001 emission line galaxies) in Field B have been measured. The results show that it is possible to derive redshift from low SNR galaxies with our post-processing and visual inspection. Our analysis also indicates that up to 1/4 of the input targets for a typical extra-galactic spectroscopic survey might be unreliable. The multi-wavelength data analysis shows that the majority of mid-infrared-detected absorption (91.3%) and emission line galaxies (93.3%) can be well separated by an empirical criterion of $W2-W3=2.4$. Meanwhile, a fainter sequence paralleled to the main population of galaxies has been witnessed both in $M_r$/$W2-W3$ and $M_*$/$W2-W3$ diagrams, which could be the population of luminous dwarf galaxies but contaminated by the edge-on/highly inclined galaxies ($\sim30\%$).Comment: 19 pages, 14 figures, 2 MRT, accepted by ApJ