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Plant functional traits and environmental changes and their adaptation mechanisms are hot topics in ecological research. Plant functional traits can reflect the adaptation of plants to different environmental conditions, fitness or productivity during long-term evolution. In this paper, the functional traits of the stems, leaves and roots of dominant woody plants in the Larix gmeliniii forest in the cold temperate zone were measured, and the environmental factors such as temperature, humidity, topography, soil and snow were measured simultaneously. The experimental results showed that the cold temperate zone, the leaf area and specific leaf area of L. gmelinii and Betula platyphylla have certain patterns|the biomass of annual branchlets of both trees is directly related to the average biomass of roots, and the biomass of annual branchlets of B. platyphylla and the snow water equivalent of the snow is directly related to the soil water content of 5–10 cm. The other environmental factors are not directly related to the annual branch biomass. The root traits of the Rododendron-L. gmelinii forest are not only directly related to other plant traits (such as leaves and stems), but also directly related to external environmental factors. It is indirectly affected by environmental factors such as soil temperature, soil water content, soil carbon-nitrogen ratio and altitude.

The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogues. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographical heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.

The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide here a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogues. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographic heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.

ForestGEO is a network of scientists and long-term forest dynamics plots (FDPs) spanning the Earth's major forest types. ForestGEO's mission is to advance understanding of the diversity and dynamics of forests and to strengthen global capacity for forest science research. ForestGEO is unique among forest plot networks in its large-scale plot dimensions, censusing of all stems ≥1 cm in diameter, inclusion of tropical, temperate and boreal forests, and investigation of additional biotic (e.g., arthropods) and abiotic (e.g., soils) drivers, which together provide a holistic view of forest functioning. The 71 FDPs in 27 countries include approximately 7.33 million living trees and about 12,000 species, representing 20% of the world's known tree diversity. With >1300 published papers, ForestGEO researchers have made significant contributions in two fundamental areas: species coexistence and diversity, and ecosystem functioning. Specifically, defining the major biotic and abiotic controls on the distribution and coexistence of species and functional types and on variation in species' demography has led to improved understanding of how the multiple dimensions of forest diversity are structured across space and time and how this diversity relates to the processes controlling the role of forests in the Earth system. Nevertheless, knowledge gaps remain that impede our ability to predict how forest diversity and function will respond to climate change and other stressors. Meeting these global research challenges requires major advances in standardizing taxonomy of tropical species, resolving the main drivers of forest dynamics, and integrating plot-based ground and remote sensing observations to scale up estimates of forest diversity and function, coupled with improved predictive models. However, they cannot be met without greater financial commitment to sustain the long-term research of ForestGEO and other forest plot networks, greatly expanded scientific capacity across the world's forested nations, and increased collaboration and integration among research networks and disciplines addressing forest science.

The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide here a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogs. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographic heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.

Spindle system is the major mechanical component in machine tools, and its performance is responsible for a significant portion of the total consumed energy of machine tools. Conventional design optimization of spindle system is partially focused on parameter optimization of spindle motor or transmission system, contributing to an increase of the motor efficiency. Given that concurrent interactions among them is complex, very little efforts has been done to conduct integration optimization for optimum energy efficiency. To this end, a new approach of spindle system design is presented with consideration of the above two aspects adequately, to achieve the maximum energy and material efficiency. Firstly, the energy characteristic of spindle system is explicitly modelled on the basis of energy flow analysis. Then, a multi-objective optimization model for parameter optimization of spindle motor and transmission system is developed to take the both maximum energy efficiency and minimum volume as objectives, which is subjecting to a set of constraints with related to the cutting parameters boundary, processing requirements and shifting power losses. Finally, a multi-objective improved teaching-learning based optimization (MO-ITLBO) algorithm is presented to solve the developed optimization model. The performance of the proposed design approach of lathe spindle system is demonstrated through different working conditions. The experimental results indicate that the design of energy and material efficient machine tools can be achieved.

With the increase of energy price and environment problem, the energy consumption of machine tool is attracting more attention. The moving components of machine tools consume a large amount of energy in the operating stage. Structure optimization of moving components is a key strategy for energy saving in machine tools design. Traditionally, structural optimization of machine tools is carried out for reducing energy consumption or improving static and dynamic performance. Given that these factors are important to the structure optimization in machine tools design, this paper presents a structural design optimization method for comprehensively considering energy consumption, static and dynamic performance of machine tool. Firstly, the energy consumption model of the moving components is proposed, and the structural performance indicators of the moving components are analyzed. Then, based on the experiment data obtained by uniform design method, five structure parameters that have great influence on performance indicators are selected as decision variables through sensitivity analysis. To improve the computation efficiency, approximation functional relationship between the five decision variables and the four performance indicators are built through response surface method (RSM). After that, an optimization objective is formulated by combining the four performance indicators through principal component analysis (PCA). Finally, a new hybrid algorithm which integrates Simulated Annealing (SA) and Particle Swarm Optimization (PSO) algorithm is developed to solve the structure optimization problem. Through calculation and analysis, it is found that there is a linear relationship between the moving part mass and energy consumption. The results show that the energy consumption of optimized structure is reduced while ensuring the static and dynamic performance.

ZnO nanowire attracted nanosheets, nanocartridges and hexagonal nanotowers are fabricated by evaporation of ZnS in the presence of trace oxygen under controlled conditions. The nanosheet has an irregular structure, and nanowires sprout from the flange of the nanosheet. The nanocartridge has one row of prismatic nanorods grown on the (0001) surface of the ZnO nanobelts. The hexagonal nanotower, which grows along the c axis, shows an interesting layer structure and seems to form by piling up hexagonal ZnO nanocrystals layer on layer. These nanomaterials might have potential applications in optoelectronics.

By the method of runoff determination in large basin combined with contrast experiment in small watershed, and based on the runoff and forest resources data in past 35 years, this paper studied the serial changes of river runoff in Xiaoxing'anling after forest harvesting. The results showed that the river flow was increased in the early 10 years after forest harvesting, but decreased gradually with the growth and crown closure of artificial larch forest, tended towards or even lower than the level before harvesting. The river runoff had a close correlation with annual rainfall and the areas of forest harvesting and regeneration. Significant positive correlation was observed between annual flow and forest harvesting area, which resulted in the increase of river runoff after forest harvesting. Forest harvesting could also significantly increase the peak flood and snowmelt runoff. There was a negative correlation between regenerated forest area and annual flow, and thus, forest regeneration would decrease annual