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Driven by digital technologies, urban forest development is at its height in China. Guided by the theories of nature- approximating forestry, potential natural vegetation and new succession, and by the Miyawaki Method, this paper explores the digital design of nature-approximating urban forest by innovatively applying widely-accepted theories with digital technologies. The paper reviews the evolution of nature-approximating urban forest and discusses why it is essential to introduce digital technologies into this type of forest's development. Based on the Miyawaki Method, this study proposes a three-step digital design approach to creating nature-approximating urban forest: cognition, simulation, and construction. Also, an empirical study on Xingtai Forest in a Hebei Green Expo Garden is conducted to analyze the digital design methods of nature-approximating urban forest. Steps include 1) cognition of plants to investigate characteristics of natural communities by collecting their key parameters; 2) construction of target communities by simulating natural communities, analyzing and classifying target habitats of designed communities by relevant software, and developing type and pattern designs of target communities; and 3) production of detailed construction schemes by utilizing Grasshopper and Python to generate digital generation clusters, after which planting design drawings and seedling information can be obtained by inputting values of key parameters. This method provides a new perspective on the digital design of nature- approximating urban forest, which helps facilitate urban forest development in an efficient way. [ABSTRACT FROM AUTHOR]

Drought has been a concern of global and regional water, carbon and energy cycles. From 1999 to 2011, North China experienced a multiyear precipitation reduction, which decreased significantly water availability as indicated by decreased soil moisture and Palmer Drought Severity Index. In this study, three light use efficiency models (CASA, MODIS-GPP and EC-LUE) and one dynamic vegetation model (IBIS) were used to characterize the impacts of long-term drought on terrestrial carbon fluxes over the North China. All of four models showed the reduction in averaged GPP of 0.026-0.047 Pg C yr-1 from 1999 to 2011 compared to 1982-2011. Based on IBIS model, simulated ecosystem respiration fell from 1999 to 2011 by 0.016 Pg C yr-1. Multiple precipitation reduction changed the regional carbon uptake of 0.0014 Pg C yr-1 from 1982 to 1998 to a net source of 0.018 Pg C yr-1. Moreover, a pronounced decrease of maize yield was found ranging from 1999 to 2011 versus the average of 1978-2011 at almost all provinces over the study region. The largest reduction of maize yield occurred in the Beijing (2499 kg ha-1 yr-1), Jilin (2180 kg ha-1 yr-1), Tianjing (1923 kg ha-1 yr-1) and Heilongjiang (1791 kg ha-1 yr-1), and maize yield anomaly was significantly correlated with the precipitation through May and September over the entire study area. Our results revealed that recent climate change, and especially drought-induced water stress, is the dominant cause of the reduction in the terrestrial carbon sink. [ABSTRACT FROM AUTHOR]

A process-oriented niche specification (PONS) model was constructed to quantify climatic controls on the distribution of ecosystems, based on the vegetation map of China. PONS uses general hypotheses about bioclimatic controls to provide a "bridge" between statistical niche models and more complex process-based models. Canonical correspondence analysis provided an overview of relationships between the abundances of 55 plant communities in 0.1° grid cells and associated mean values of 20 predictor variables. Of these, GDD (accumulated degree days above 0 ° C) Cramer--Prentice α (an estimate of the ratio of actual to equilibrium evapotranspiration) and mGDD5 (mean temperature during the period above 5 ° C) showed the greatest predictive power. These three variables were used to develop generalized linear models for the probability of occurrence of 16 vegetation classes, aggregated from the original 55 types by k-means clustering according to bioclimatic similarity. Each class was hypothesized to possess a unimodal relationship to each bioclimate variable, independently of the other variables. A simple calibration was used to generate vegetation maps from the predicted probabilities of the classes. Modelled and observed vegetation maps showed good to excellent agreement (κ = 0.745). A sensitivity study examined modelled responses of vegetation distribution to spatially uniform changes in temperature, precipitation and [CO2], the latter included via an offset to α (based on an independent, data-based light use efficiency model for forest net primary production). Warming shifted the boundaries of most vegetation classes northward and westward while temperate steppe and desert replaced alpine tundra and steppe in the southeast of the Tibetan Plateau. Increased precipitation expanded mesic vegetation at the expense of xeric vegetation. The effect of [CO2] doubling was roughly equivalent to increasing precipitation by ~ 30%, favouring woody vegetation types, particularly in northern China. Agricultural zones in northern China responded most strongly to warming, but also benefited from increases in precipitation and [CO2]. These results broadly conform to previously published findings made with the process-based model BIOME4, but they add regional detail and realism and extend the earlier results to include cropping systems. They provide a potential basis for a broad-scale assessment of global change impacts on natural and managed ecosystems. [ABSTRACT FROM AUTHOR]

The topic of health has gained importance in today's society in the context of a healthy China. The success of community environmental design is intimately correlated with everyone's physical and mental health since it is the setting for people's daily lives. At present, although the facilities and equipment of the community environment in our country are improving day by day, the important role of color psychology in the community environment has been neglected. Color has always been a part of human life and a very important component of the community environment. When it comes to the design of communal environments, the color design of various areas will have variable degrees of influence on the psychological space and perspective of individuals. Therefore, the purpose of this paper is to investigate the application value of color psychology in the design of community health environments using color psychology as a scientific foundation. Additionally, the paper attempts to use color psychology as a scientific basis to study the thinking of health issues in the community environment. In addition, the results of the questionnaire survey are used to perform analysis and discussion in order to investigate the regular characteristics of the various research objects, as well as their preferences and psychological needs for color. This is done with the goal of providing empirical support for the improvement of the community environment and the health of the people living in it. In the end, the results of the questionnaire survey are compiled with four different design concepts. These design principles include functionality, naturalness, beauty, and safety. And the design intention and optimization strategy from the three directions the overall building, planting, and paving in the community healthy environment are then presented. This is done in order to create a colorful and comfortable healthy environment for the community life of people and to support the development of people's physical and mental health. [ABSTRACT FROM AUTHOR]

The coupling of the carbon and nutrient cycles drives the food web structure and biogeochemistry of ecosystems. However, across precipitation gradients, there may be a shift in C and N pools from above- to belowground because of shifting plant stoichiometry and allocation. Here, we present a study which is the first to explicitly compare above- and belowground pool sizes of N and C within predominant plant species along precipitation gradient. We dissected these pools into biomass allocation and nutrient concentrations. Based on previous evidence, biomass allocation to roots should increase with aridity, while leaf [N] should increase. If their effect sizes are equal, they should cancel each other out, and the above- and belowground proportions of the N would remain constant. Along a precipitation gradient in Chinese steppe zone, the effect sizes of the biomass shifts were remarkably consistent among the predominant species, Stipa grandis. The effect sizes of biomass allocation and [N] were equal and the proportion of N of above- and belowground did not change with aridity, but the shift in leaf [C] with aridity was much weaker than the biomass shift, leading to a decrease in the proportion of C belowground at dry sites. Precipitation gradients do decouple the C and N pool of S. grandis along a precipitation gradient in Chinese steppe zone. [ABSTRACT FROM AUTHOR]

Abstract: Scientific assessment of the health of wetland ecosystem is an important prerequisite for wetland management and protection. The Zoige wetland ecosystem is a cold peat wetland ecosystem on the eastern edge of the Tibetan Plateau in southwest China. By measuring organic matter and nutrients from soil samples in the Zoige wetland, we found that there were connections between organic matter in soil and vegetation growth, since decomposition of soil organic matter was an important source of soil nutrients and was influenced by the soil water content of the wetland. We therefore integrated a cluster of geochemical indicators of soil, including organic matter content, total nitrogen, total phosphorus content, total potassium content and humic acid yield, into a conceptual framework for ecosystem health assessment, therefore improving the existing indicator system for the Zoige wetland. We analyzed levels of organic matters and nutriment elements in soil samples from the Zoige wetland simultaneously with other indicators of the assessment system. Compared with the previous assessment work for Zoige wetland, the proposed assessment system showed a more holistic result. [Copyright &y& Elsevier]

In China, cumulative changes in climate and land use/land cover (LULC) from 1981 to 2000 had collectively affected the net productivity in the terrestrial ecosystem and thus the net carbon flux, both of which are intimately linked with the global carbon cycle. This paper represents the first national effort of its kind to systematically investigate the impact of changes of LULC on carbon cycle with high-resolution dynamic LULC data at the decadal scale (1990s and 2000s). The CEVSA was applied and driven by high resolution LULC data retrieved from remote sensing and climate data collected from two ground-based meteorological stations. In particular, it allowed us to simulate carbon fluxes (net primary productivity (NPP), vegetation carbon (VEGC) storage, soil carbon (SOC) storage, heterotrophic respiration (HR), and net ecosystem productivity (NEP)) and carbon storage from 1981 to 2000. Simulations generally agree with output from other models and results from bookkeeping approach. Based on these simulations, temporal and spatial variations in carbon storage and fluxes in China may be confirmed and we are able to relate these variations to climate variability during this period for detailed analyses to show influences of the LULC and environmental controls on NPP, NEP, HR, SOC, and VEGC. Overall, the increases in NPP were greater than HR in most of the time due to the effect of global warming with more precipitation in China from 1981 to 2000. With this trend, the NEP remained positive during that period, resulting in the net increase of total amount of carbon being stored by about 0.296 PgC within the 20-years time frame. Because the climate effect was much greater than that of changes of LULC, the total carbon storage in China actually increased by about 0.17 PgC within the 20 years. Such findings will contribute to the generation of control policies of carbon emissions under global climate change. [ABSTRACT FROM AUTHOR]

Biological stabilization within accumulated soil organic carbon (SOC) has not been well understood, while its role in physical and chemical protection as well as of chemical recalcitrance had been addressed in Chinese rice paddies. In this study, topsoil samples were collected and respiratory activity measured in situ following rice harvest under different fertilization treatments of three long-term experimental sites across southern China in 2009. The SOC contents, microbial biomass carbon (SMBC) and nitrogen (SMBN) were analysed using chemical digestion and microbial community structure assessment via clony dilute plate counting methods. While SOC contents were consistently higher under compound chemical fertilization (Comp-Fert) or combined organic and inorganic fertilization (Comb-Fert) compared to N fertilization only (N-Fert), there was significantly higher fungal-bacterial ratio under Comb-Fert than under N-Fert and Comp-Fert. When subtracting the background effect under no fertilization treatment (Non-Fert), the increase both in SMBC and SMBN under fertilization treatment was found very significantly correlated to the increase in SOC over controls across the sites. Also, the ratio of culturable fungal to bacterial population numbers (F/B ratio) was well correlated with soil organic carbon contents in all samples across the sites studied. SOC accumulation favoured a build-up the microbial community with increasing fungal dominance in the rice paddies under fertilization treatments. While soil respiration rates were high under Comb-Fert as a result of enhanced microbial community build-up, the specific soil respiratory activity based on microbial biomass carbon was found in a significantly negatively correlation with the SOC contents for overall samples. Thus, a fungal-dominated microbial community seemed to slow SOC turnover, thereby favouring SOC accumulation under Comp-Fert or under Comb-Fert in the rice paddies. Therefore, the biological stabilization process is of importance in SOC sequestration in the rice paddies, operating with physical and chemical protection and chemical recalcitrance. However, sufficient understanding and prediction of SOM dynamics needs further quantitative characterization of the simultaneous operation of several mechanisms. [ABSTRACT FROM AUTHOR]

Highlights • Forest resource Metabolism Network model isdeveloped for ecological and economic analysis. • Exploitation index is developed to reveal the weaker sectors in the ecological relations. • A case study of Guangdong province, China isconducted to illustrate the potential benefits. • Scientific Basis are provided to allocate forestresources and stabilize industrial structure. Abstract Integrating forest resources into the socio-economic system correctly and reasonably is of vital importance to tackle the increasingly scarce forest resources. In this paper, forest resource input-output model and forest resource metabolism network model are established to provide new insights into the relationships among the systems, industries and sectors related to forest resources. A promising indicator named exploitation index is developed to reveal the weaker sectors in the ecological relations, which will further help to provide better corrective actions and integrated strategic measures. Guangdong is taken as an example to verify the availability of the model and solve the problem. The results show that the primary manufacturing consumes more direct timber, while advanced manufacturing and the service sector utilize timber indirectly. In addition, Guangdong forest metabolism system shows a negative correlation and the whole network does not achieve the mutualism state, leading to competition relationships between pairwise sectors that should not appear, such as Forestry sector and Papermaking and Paper Products sector. These results provide the corresponding reference for helping the decision makers to allocate forest resources and coordinate ecological and economic development. [ABSTRACT FROM AUTHOR]

Changes in precipitation patterns and nitrogen (N) cycling across the globe are likely to affect ecosystem primary productivity and CO2 exchanges, especially in the arid and semi-arid grasslands because of their co-limitation of water and N supply. To evaluate the effects of water and N availability on ecosystem CO2 fluxes, we conducted a manipulative field experiment with water and N addition in a temperate steppe of Northern China. The growing-season CO2 fluxes, including net ecosystem exchange (NEE), gross ecosystem photosynthesis (GEP) and ecosystem respiration (ER) were examined in 2006 and 2007 with remarkably different amount of precipitation. Net carbon uptakes were found in all of treatments over the growing season in both years. However, their magnitude had inter-annual variations which coincided with the seasonal changes of precipitation amount. During these two growing seasons, water and N addition significantly increased NEE, owing to higher stimulation of GEP than ER. Our results suggest that net primary productivity, especially dominant species' biomass, correlated closely with variations in GEP and ER. Soil moisture was the driving environmental factor controlling seasonal and inter-annual variability in GEP and ER subsequently inducing changes in NEE. Moreover, the strengths of both water and N addition effects were greatly depended on the initial water condition in this temperate typical steppe. [ABSTRACT FROM AUTHOR]

The dendrolites composed of light gray massive micrite limestone occur at the top of the Cambrian Zhangxia Formation in Houziyu Section, Zibo, Shandong Province. Because it is very difficult to study the genesis of microbial rocks through "the function of diagenesis filter," this paper analyzes its genetic mechanism by characterizing the sedimentary fabric and formation environment of dendrolites and it is of great significance to study microbial carbonate deposited in geological history in oil exploration. The Cambrian Zhangxia Formation in the Houziyu section is a marine deposit. The macroscopic shrub-like fabric of centimeter scale can be seen on the surface of the tree-shaped stone, with small biological burrows and remnants of calcareous mud components after filling. The microstructure observation shows that the main fabric of the dendrolites is a dark micrite matrix, bright calcite cement, clastic particles, and a calcified cyanobacteria biological community. Detailed supplementary information on the diversity of calcified microorganisms in dendrolites has been made through the study of various types of calcified cyanobacteria and calcified residual substances in the microbial membrane of calcified cyanobacteria in the dendrolites of the study area. It is clear that dendrolites are the product of the calcification of biofilms or microbial mats dominated by cyanobacteria. With the deepening of this kind of research, it is bound to raise the research of microbial carbonate to a new level in China and provide great help to find oil and gas resources in marine strata of microbial origin in China. [ABSTRACT FROM AUTHOR]

The goal of this study was to quantify the roles of plants and soil in the N2O budget of a cropland in North China. Plant and soil N2O fluxes were measured with transparent and dark plant chambers and soil chambers, respectively, in three adjacent fields of fertilized cotton, fertilized maize and unfertilized soybean. During the observation period, the soil flux was 448 ± 89, 230 ± 74 and 90 ± 14 µg N2O m-2 h-1 in cotton, maize and soybean fields, respectively. The plant flux was 54 ± 43 and 16 ± 41 µg N2O m-2 h-1, about 10% and 26% to the total ecosystem flux, for the cotton and the soybean field, respectively. Ignoring the contribution of plants would cause an obvious underestimation on the ecosystem N2O flux. The influence of sunlight on plant N2O flux was insignificant. However, in the cotton field, the responses of the plant N2O flux to air temperature and soil ammonium content were significant under sunlight but insignificant under darkness, suggesting that stomatal activity might influence the release process. In the cotton field, temperature sensitivity of plant N2O emission was 1.13, much lower than the value of soil flux (5.74). No relationship was found between plant N2O flux and soil nitrate content. It was implied that nitrate reduction in plants might not be the main source of plant N2O emission under field conditions. The seasonal patterns of the soil and plant N2O emissions were similarly affected by fertilization, indicating that plants might serve as a passive conduit transporting N2O produced in the soil. [ABSTRACT FROM AUTHOR]

It is well established that tropical forest ecosystems are often limited by phosphorus (P) availability, and elevated atmospheric nitrogen (N) deposition may further enhance such P limitation. However, it is uncertain whether P availability would affect soil fluxes of greenhouse gases, such as methane (CH4) uptake, and how P interacts with N deposition. We examine the effects of N and P additions on soil CH4 uptake in an N saturated old-growth tropical forest in Southern China to test the following hypotheses: (1) P addition would increase CH4 uptake; (2) N addition would decrease CH4 uptake; and (3) P addition would mitigate the inhibitive effect of N addition on soil CH4 uptake. Four treatments were conducted at the following levels from February 2007 to October 2009: control, N-addition (15 g N m-2 yr-1), P-addition (15 g P m-2 yr-1), and NP-addition (15 g N m-2 yr-1 plus 15 g P m-2 yr-1). Static chamber and gas chromatography techniques were used to quantify soil CH4 uptake every month throughout the study period. Average CH4 uptake rate was 31.2 ± 1.1 µg CH4-C m-2 h-1 in the control plots. The mean CH4 uptake rate in the N-addition plots was 23.6 ± 0.9 µg CH4-C m-2 h-1, significantly lower than that in the controls. P-addition however, significantly increased CH4 uptake by 24% (38.8 ± 1.3 µg CH4-C m-2 h-1), whereas NP-addition (33.6 ± 1.0 µg CH4-C m-2 h-1) was not statistically different from the control. Our results suggest that increased P availability may enhance soil mathanotrophic activity and potentially mitigate the inhibitive effect of N deposition on CH4 uptake in tropical forests. Phosphorus and nitrogen treatments also significantly changed the fluxes of greenhouse gases N2O and CO2, altering the net global warming potential (GWP) of this tropical forest located in a high-N deposition zone of Southern China. [ABSTRACT FROM AUTHOR]

Chinese grasslands are extensive natural ecosystems that comprise 40% of the total land area of the country and are sensitive to N deposition. A field experiment with six N rates (0, 30, 60, 120, 240, and 480 kg N ha-1 yr-1) was conducted at Duolun, Inner Mongolia, during 2005 and 2010 to identify some effects of N addition on a temperature steppe ecosystem. The dominant plant species in the plots were divided into two categories, grasses and forbs, on the basis of species life forms. Enhanced N deposition, even as little as 30 kg N ha-1 yr-1 above ambient N deposition (16 kg N ha-1 yr-1), led to a decline in species richness. The cover of grasses increased with N addition rate but their species richness showed a weak change across N treatments. Both species richness and cover of forbs declined strongly with increasing N deposition as shown by linear regression analysis (p < 0.05). Increasing N deposition elevated aboveground production of grasses but lowered aboveground biomass of forbs. Plant N concentration, plant δ15N and soil mineral N increased with N addition, showing positive relationships between plant δ15N and N concentration, soil mineral N and/or applied N rate. The cessation of N application in the 480 kg N ha-1 yr-1 treatment in 2009 and 2010 led to a slight recovery of the forb species richness relative to total cover and aboveground biomass, coinciding with reduced plant N concentration and soil mineral N. The results show that N deposition induced changes in soil N transformations and plant N assimilation that are key to changes in species composition and biomass accumulation in this temperate steppe ecosystem. [ABSTRACT FROM AUTHOR]

Methane (CH4) emissions from natural wetland ecosystems exhibit large spatial variability. To understand the underlying factors that induce differences in CH4 emissions from natural wetlands around China, we measured the CH4 production potential and the abundance of methanogenic archaea in vertical profile soils sampled from the Poyang wetland in the subtropical zone, the Hongze wetland in the warm temperate zone, the Sanjiang marsh in the cold temperate zone, and the Ruoergai peatland in the Qinghai-Tibetan Plateau. The top soil layer had the highest population of methanogens (1.07-8.29 x 109 cells g-1 soil) in all wetlands except the Ruoergai peatland and exhib ited the maximum CH4 production potential measured at the mean in situ summer temperature. There is a significant logarithmic correlation between the abundance of methanogenic archaea and the soil organic carbon (R2 =0.718,P<0.001,n =13) and between the abundance of methanogenic archaea and the total nitrogen concentrations (R2 =0.758, P <0.001, n=13) in wetland soils. This indicates that the amount of soil organic carbon may affect the population of methanogens in wetland ecosystems. While the CH4 production potential is not significantly related to methanogen population (R2 = 0.011, P > 0.05, n = 13), it is related to the dissolved organic carbon concentration (R2 =0.305, P =0.05, n=13) This suggests that the methanogen population is not an effective index for predicting the CH4 production in wetland ecosystems. The CH4 production rate of the top soil layer increases with increasing latitude, from 274 μgCH4 kg-1 soil d-1 in the Poyang wetland to 665 μgCH4 kg-1 soil d-1 in the Carex lasiocarpa marsh of the Sanjiang Plain. The CH4 production potential in the freshwater wetlands of Eastern China is affected by the supply of methanogenic substrates rather than by temperature, whereas the supply of substrates was mainly affected by the position and stability of the wetland water table. In contrast, low summer temperatures at high elevations in the Ruoergai peatland of the Qinghai-Tibetan Plateau result in the presence of dominant species of methanogens with low CH4 production potential rather than the reduction of the supply of methanogenic substrates, which in turn suppresses CH4 production. [ABSTRACT FROM AUTHOR]

The natural environment plays a good role in guiding people's psychology. The topic of rehabilitation landscape has increasingly become a hot topic studied by many scholars. In the environment that home-based elderly care has gradually become the main way of elderly care in the future, the natural environment of the community has become particularly important. At present, the construction of rehabilitation landscape in the community has not attracted widespread attention. In this paper, starting from rehabilitation landscape perspective, and deeply investigating landscape environment of outdoor activity space in college community, evaluation of the elderly group on its current situation and future needs are understood, and the aging creation orientation of rehabilitation landscape in college community in the future is explored. It could provide theoretical reference for effectively improving the living standard of the elderly, and actual significance and practical basis for proposing design strategy of rehabilitation landscape in China. [ABSTRACT FROM AUTHOR]

The end Permian to Middle Triassic interval (∼252–242 Ma) witnessed the largest marine mass extinction and the most delayed recovery in the Phanerozoic. The nature and mechanism of these biotic and environmental changes remain unclear. This special issue focuses on the Triassic marine sediments in South China, which provide unique documentation of the collapse and recovery of marine ecosystems. Six papers focus on biotic changes and their ecological significance in Early and Middle Triassic times, documenting evidence from bivalves, marine reptiles, stromatolites, hybodontid teeth, vertebrate coprolites, and other putative fossils. Two papers study conodont biostratigraphy across the Permian-Triassic boundary (PTB) and Induan-Olenekian boundary. Two papers reconstruct the palaeoenvironments of the Early Triassic Chaohu Fauna and Middle Triassic Luoping Biota. Two further papers present new marine δ13C records and biomarker data and link them to volcanic eruptions in Early Triassic times. These new findings are important for understanding the co-evolution between biotic and environmental changes in the aftermath of Permian-Triassic boundary mass extinction. [ABSTRACT FROM AUTHOR]

Models of marine ecosystem dynamics play an important role in revealing the evolution mechanisms of marine ecosystems and in forecasting their future changes. Most traditional ecological dynamics models are established based on basic physical and biological laws, and have obvious dynamic characteristics and ecological significance. However, they are not flexible enough for the variability of environment conditions and ecological processes found in offshore marine areas, where it is often difficult to obtain parameters for the model, and the precision of the model is often low. In this paper, a new modeling method is introduced, which aims to establish an evolution model of marine ecosystems by coupling statistics with differential dynamics. Firstly, we outline the basic concept and method of inverse modeling of marine ecosystems. Then we set up a statistical dynamics model of marine ecosystems evolution according to annual ecological observation data from Jiaozhou Bay. This was done under the forcing conditions of sea surface temperature and surface irradiance and considering the state variables of phytoplankton, zooplankton and nutrients. This model is dynamic, makes the best of field observation data, and the average predicted precision can reach 90% or higher. A simpler model can be easily obtained through eliminating the terms with smaller contributions according to the weight coefficients of model differential items. The method proposed in this paper avoids the difficulties of obtaining and optimizing parameters, which exist in traditional research, and it provides a new path for research of marine ecological dynamics. [ABSTRACT FROM AUTHOR]

Midlatitude regions experienced frequent droughts during the twentieth century, but their impacts on terrestrial carbon balance are unclear. This paper presents a century-scale study of drought effects on the carbon balance of terrestrial ecosystems in China. The authors first characterized the severe extended droughts over the period 1901–2002 using the Palmer drought severity index and then examined how these droughts affected the terrestrial carbon dynamics using tree-ring width chronologies and a process-based biogeochemistry model, the Terrestrial Ecosystem Model (TEM). It is found that China suffered from a series of severe extended droughts during the twentieth century. The major drought periods included 1920–30, 1939–47, 1956–58, 1960–63, 1965–68, 1978–80, and 1999–2002. Most droughts generally reduced net primary productivity (NPP) and net ecosystem productivity (NEP) in large parts of drought-affected areas. Moreover, some of the droughts substantially reduced the countrywide annual NPP and NEP. Out of the seven droughts, three (1920–30, 1965–68, and 1978–80) caused the countrywide terrestrial ecosystems to switch from a carbon sink to a source, and one (1960–63) substantially reduced the magnitude of the countrywide terrestrial carbon sink. Strong decreases in NPP were mainly responsible for the anomalies in annual NEP during these drought periods. Changes in heterotrophic respiration happened in the same direction, but mostly with smaller magnitude. The results show that severe extended droughts had significant effects on terrestrial carbon cycling in China, although future studies should consider other important processes such as drought-induced mortality and regrowth, land-use change, disturbances (e.g., fire), human management (e.g., fertilization and irrigation), and environmental pollution (e.g., ozone pollution, nitrogen deposition). These drought effects are of particular importance in light of projected widespread summer drying in midlatitude regions during the twenty-first century. Future droughts could lead to a reduced terrestrial carbon sink or even a source and exert a positive feedback to the global climate system. [ABSTRACT FROM AUTHOR]

Background: Due to their relative isolation, the previous studies of Monpa plant use were only conducted in north-east India. In October 2013, Mêdog County was no longer remote, thanks to completion of a highway into the county. This study of plant species used by the Monpa had three research objectives. These were (i) to identify and record local names and uses of plants in Mêdog County, (ii) to assess which of these were uses of endemic or near-endemic species within this part of the Indo-Burma biodiversity hotspot, and (iii) to assess how plant uses reflect socio-economic change in Mêdog County? Methods: Field surveys were conducted in 12 villages of four townships in Mêdog County, Tibet, China. Two field visits were made. The first field trip was in November 2017 and the second field trip was in May 2018. We interviewed 64 key informants between 21 and 84 years old. Most of them were the village leaders and other local people who are knowledgeable about plants. After transect walks with knowledgeable local people, we used free listing, key informant interviews, and semi-structured interviews during the field work. Plants traditionally used by the Monpa were documented. Utilization frequency was used to assess the significance of each species, and the Cultural Importance index was used to estimate the cultural significance of the species in common. We also used the informant consensus factor (FIC) to determine the homogeneity of the informants' knowledge of medicinal plants. Results: One hundred ninety-four plant species belonging to 82 families and 158 genera were recorded and collected. One hundred twenty-two species, primarily fruits, were food plants. Forty-five species were used as traditional medicines. This included highly valued species collected in alpine areas (Paris polyphylla) and brought to villages in Mêdog, which are at a lower altitude (between 728 and 1759 m a.s.l). Seven edible plant species were also used as herbal medicines. We also recorded 39 species used for other purposes in Monpa daily life. These included nine species that were used to make agricultural tools, five species for dyes and mordants, four species for timber, three species for fuelwood, four species for religious ritual use, three species for washing, two species for incense, two species for thatching, two species for fiber (rope and paper), two "calendar plants" were used to indicate seasons for agricultural purposes, two fish poison plant species, and one species were used as a tobacco substitute. Based on taxonomic insights and from studies elsewhere, we suggested that fiber species were under-reported (c. 14 species were used vs. one species reported used). Even though these plant species are rich and diverse, the use of endemic or near-endemic species was rarely recorded in previous studies. These species included Arenga micrantha (used for starch), Hornstedtia tibetica (fruits), Castanopsis clarkei (edible nuts) and Gnetum pendulum (edible nuts), Ophiorrhiza medogensis (vegetables), Derris scabricaulis (fish poison), Radermachera yunnanensis (agricultural tools), Litsea tibetana (seed oil), Dendrocalamus tibeticus (wine strainers and implements for administering medicine), Zanthoxylum motuoense (spices), Cinnamomum contractum (tobacco substitutes), Morus wittiorum (medicines), and Garcinia nujiangensis (funeral rituals). Despite the absence of roads until 2013 and the impression of "isolation," Monpa knowledge of plant use reflects three categories of change. Firstly, oral histories of plants used in Bhutan were also encountered by Monpa people after their migration from Bhutan to south-eastern Tibet. Secondly, a "slow change" through centuries of exchange of knowledge (for example of Chinese and Tibetan medical systems), seeds of introduced crops (finger millet (indigenous to Africa), maize (from Meso-America)), and experimentation and use of introduced medicinal plants (such as Datura stramonium, which originates from North America). Thirdly, "fast change" over the past decade. This is reflected in changes in traditional architecture and in rising commercial trade in selected plant resources such as Dendrobium orchid stems and Paris polyphylla rhizomes which are in demand in China's Traditional Chinese Medicine (TCM) markets). Conclusions: Monpa people in the south-eastern Tibet have detailed knowledge of the diverse plant resources. But that traditional knowledge is now faced with a crisis because of the modern socio-economic change. In addition, Monpa knowledge of plants reflects slower changes in knowledge as well. For example, Monpa ethnomedicine has been influenced by traditional Tibetan and Chinese medicine over a longer period in time. Overall, this study provides a deeper understanding of the Monpa peoples' knowledge on wild plants, including endemic and near-endemic species whose uses have not been previously recorded. Several of these narrowly distributed species, such as the fish poison Derris scabricaulis, could be the focus of further studies. Some wild edible plants may also have interesting dietary constituents which need in-depth studies. These detailed studies could enable the Monpa people to benefit from the use of their traditional plant-derived culture and therefore support the biodiversity conservation. [ABSTRACT FROM AUTHOR]

The midpoint impact assessment methodology and several weighting methods that are currently used by most building Life cycle assessment (LCA) researchers in China, still have some shortcomings. In order to make the evaluation results have better temporal and spatial applicability, the endpoint impact assessment methodology was adopted in this paper. Based on the endpoint damage oriented concept, four endpoints of resource exhaustion, energy exhaustion, human health damage and ecosystem damage were selected according to the situation of China and the specialties of the building industry. Subsequently the formula for calculating each endpoint, the background value for normalization and the weighting factors were defined. Following that, an endpoint damage oriented model to evaluate the life cycle environmental impact of buildings in China was established. This model can produce an integrated indicator for environmental impact, and consequently provides references for directing the sustainable building design. [ABSTRACT FROM AUTHOR]

Modeling land use/cover scenario changes and its potential impacts on structure and functions of ecosystem in typical regions are helpful to understanding the interactive mechanism between land use/cover system and ecosystem. Based on the analysis of the existing land use/cover simulation and forecast models, a land use/cover scenario dynamics model by the integration of System Dynamics (SD) model, Back Propagation Neural Network (BPNN) and Cellular Automata (CA) model is developed with land use/cover scenario changes in northern China in the next 30 years and simulated in this paper. The model is to simulate the land use/cover scenario demands by using a SD model at first, and then allocating the land use scenario patterns at the local scale with the considerations of land use/cover suitability, inheritance ability and neighborhood effect by using BPNN-CA model to satisfy the balance between land use/cover scenario demands and supplies. It integrates the advantages of SD, BPNN and CA. Macro-driving factors and the micro-spatial pattern are also fully taken into account. The BPNN simplifies the identification of the factors' weights used in CA model and improves the reliability of the simulation results. The simulation accuracy of the model developed in this paper was found to be about 74%. It suggests that the model has the ability to reflect the complexity of land use/cover system at different scales to some extent and it is a useful tool for assessing the potential impacts of land use system on ecosystem. The simulated results also indicate that the urban land, water area and forest will increase significantly, and farmland and unable land will decrease gradually. Obvious land use/cover changes will take place in the farming-pastoral zone and the southeast area of northern China. [ABSTRACT FROM AUTHOR]

During the last decade, several Bohaiornis-like enantiornithine species—and numerous specimens—have been recognized from the celebrated Jehol Biota of northwestern China. In this paper, we describe the anatomy of another “bohaiornithid” species from the 125 million-year-old Yixian Formation of Liaoning Province, China. The new taxon differs from previously recognized “bohaiornithids” on a number of characters from the forelimb and shoulder girdle. We also provide a new phylogenetic framework for enantiornithine birds, which questions the monophyly of the previously recognized bohaiornithid clade and highlights ongoing challenges for resolving enantiornithine interrelationships. Additionally, we offer the first assessment of the flight properties of Bohaiornis-like enantiornithines. Our results indicate that while “bohaiornithids” were morphologically suited for flying through continuous flapping, they would have been unable to sustain prolonged flights. Such findings expand the flight strategies previously known for enantiornithines and other early birds. [ABSTRACT FROM AUTHOR]

Beta diversity patterns along environmental gradients and underlying mechanisms constitute key research inquiries in biogeography. However, ecological processes often also influence the functional traits of biological communities, making the assessment of functional β‐diversity crucial. Ground beetles (Coleoptera: Carabidae) are one of the most species‐rich groups in the insect community, displaying strong habitat specificity and morphological differences. In this study, we explored the patterns of taxonomic and functional beta diversity in ground beetle communities along the altitudinal gradient of warm‐temperature forests. By partitioning beta diversity into turnover and nestedness components, we evaluated their relationship with spatial distance. Our findings indicate a decline in species and functional trait similarity with increasing elevation and geographic distance. Further analysis attributed both types of beta diversity in carabids to a combination of dispersal limitation and environmental filtering, with elevation and geographic distance emerging as significant factors. Interestingly, forest‐type variations were found to have no impact on the beta diversity of these communities. Our study reveals the impact of environmental filtering and dispersal limitation on both taxonomic and functional beta‐diversity, shedding light on carabid community assembly in localized warm‐temperature forest areas in eastern China. [ABSTRACT FROM AUTHOR]

Afforestation is an effective approach for restoring degraded ecological functions in the dry-hot valleys of southwest China. Afforestation can affect soil carbon and nitrogen storage; however, how it affects soil P fractions, and their driving factors. is poorly understood in this region. To address these questions, we conducted a field study of Leucaena leucocephala plantations at three different stand age sites (3, 10, and 20 years) and an adjacent natural shrub-grass community control site to investigate changes in soil total phosphorus (Pt), Pi (inorganic phosphorus), Po (organic phosphorus), and phosphorus (P) fractions and their driving factors. Soil Pt, Po, labile P, and moderately labile P significantly increased in the Leucaena leucocephala plantation compared with the natural shrub grass site, and the Leucaena leucocephala plantation increased soil Pt content by significantly increasing soil Po. Soil Pt, Po, Pi, labile P, moderately labile P and non-labile P were not significantly different among the different stages of the Leucaena leucocephala plantation, and soil Pt and its fractions were all significantly higher in the middle-age forest stage of the Leucaena leucocephala plantation. These results indicate that Leucaena leucocephala plantations increased the soil P transformation ability, and soil Po played a critical role in sustaining soil P availability. The middle-age forest stage of Leucaena leucocephala plantations had the best conditions for P stocks and P conversion capacity. The abundance of actinomycetes and fungi showed significant positive relationships with soil Pi fractions (NaHCO3-Pi, NaOH-Pi, and NaOHu.s.-Pi); soil Pt and moderately labile P were significantly and directly influenced by fungal abundance. Soil organic carbon (SOC), NH4+-N, and NO3−-N showed significant and positive relationships with the soil Pi fractions (NaHCO3-Pi, NaHCO3-Po, and HCl-Po). SOC and NO3−-N were the key drivers of soil Pt, labile P, moderately labile P and non-labile fractions. These results indicate that abiotic and biotic factors differently affected the soil P fractions and Pt in Leucaena leucocephala plantations in the dry-hot valley. [ABSTRACT FROM AUTHOR]

Until now, the earliest fossil echinoderms have been predominantly known from the early Cambrian of Laurentia and West Gondwana. Here, we describe Sprinkleoglobus extenuatus gen. et sp. nov. from the Chengjiang biota (Cambrian Series 2, Stage 3) of Yunnan Province, China. The overall profile of the theca and the morphology of the ambulacra clearly establish it as an edrioasteroid echinoderm. This represents the first discovery of an unequivocal echinoderm from the early part of the Cambrian of South China and is among the oldest records of echinoderms globally. Our material shows that edrioasteroids were diverse and widely distributed from their first occurrence in the fossil record, suggesting an earlier origin for the group. We infer that Sprinkleoglobus and other early echinoderms were adapted for attaching to hard substrates, implying that the so‐called Cambrian substrate revolution was not a strong control on the early evolution of attachment in echinoderms. [ABSTRACT FROM AUTHOR]

Ecologists have generally concluded that species distributions are not random (e.g. aggregate), based on single‐species studies that applied single‐species–based statistical methods, like the negative binomial model. Although it is common knowledge that some specific species in an ecological community present aggregate distributions, this does not necessarily imply that the entire community presents an aggregate distribution. Studying community‐level distributional aggregation patterns requires different statistical methods.Herein, by utilizing a novel conspecific‐encounter index derived from a multiple species Markov transition model that accounts for the non‐independent sampling of consecutive individuals along line transects, we were able to show that tree assemblages in tropical forest ecosystems can present a strong signal of extensive distributional interspersion.This interesting result is not unexpected, given the fact that neighbouring tree individuals in highly diverse tropical forests are usually of different species, resulting in strong niche packing or interspersed patterns. In contrast, for the amphibian assemblages surveyed from southwestern China and central‐south Vietnam, the conspecific‐encounter index was found to be consistently high, implying that amphibian communities tend to be highly aggregate in space.Conclusively, using the conspecific‐encounter index derived from the Markov non‐independent sampling model, we provide a legible definition of community‐level distributional aggregation as an interspersed or cluster‐like distribution of different species. This definition is not idiosyncratic, as it is coincident with the definition of the contagion index used in landscape ecology. To this end, the model used in this paper establishes a framework explicitly linking community ecology and landscape ecology from a multi‐object perspective. [ABSTRACT FROM AUTHOR]

Microbial communities associated with seagrass beds play a crucial role in maintaining the balance of seagrass ecosystems. However, the driving mechanisms behind the structure and functional succession of seagrass microbial communities are still unclear despite the close interaction between seagrass and surrounding microorganisms. To enhance our knowledge of the diversity and functional characteristics of microbial communities in seagrass beds, we employed 16S rRNA gene amplicon sequencing to investigate bacterial communities in seagrass leaves, roots, seawater, and sediments in Caofeidian Zostera marina seagrass beds of Hebei Province, Northern China. Our results highlighted that specific types of bacteria were enriched in different sample compartments, indicating the importance of habitat in influencing microbial diversity and community structure in seagrass bed ecosystems. Notably, the microbial community structure of seagrass leaves and roots showed more similarity to that found in seawater and sediments. Among all the samples, the phylum Pseudomonadota exhibited the highest relative abundance, particularly in sediment samples where they accounted for over 95% of the total bacterial population. In addition, the enrichment of Vibrio, an opportunistic pathogen in several plant samples, alerted us to seagrass and its surrounding marine environments. Finally, functional predictions of microbial communities using PICRUSt2 revealed variations in microbial functions, indicating specific metabolic preferences of microbial communities in different natural environments. The present research sheds light on the mechanisms underlying microbial community succession and their ecological function in seagrass beds. [ABSTRACT FROM AUTHOR]

Aim: Understanding the patterns and drivers of biodiversity across space and time is commonly based on species diversity, which may ignore species' functional role and evolutionary history and result in an incomplete understanding of community assembly. It is suggested that integrating species, functional, and phylogenetic diversity could provide a more holistic assessment of community assembly in natural ecosystems. This study aimed to explore the elevational patterns and environmental drivers of multiple facets of fish diversity and community structure in a subtropical river during the wet and dry seasons. Location: The Chishui River basin, China. Methods: We investigated the responses of fish species richness, functional richness, and phylogenetic diversity to elevation in different seasons. Moreover, we compared functional dispersion and mean pairwise distance with those obtained from null models to infer assembly mechanisms shaping community structure. Additionally, we examined the environmental drivers (e.g. water chemistry, temperature, and river size) of fish diversity and community structure. Results: Fish species richness, functional richness, and phylogenetic diversity showed a negative relationship with elevation in the Chishui River basin. Fish communities tended to be on average functionally random but phylogenetically clustered. Furthermore, phylogenetic structure exhibited a decreasing pattern along the elevational gradient. Despite no significant seasonal changes for fish diversity (except for phylogenetic diversity), fish communities became more phylogenetically overdispersed and clustered at low and high elevations in the dry season. Additionally, the responses of fish diversity and community structure to environmental variables were not synchronous. Conclusions: At the basin scale, environmental filtering was prevalent in shaping fish phylogenetic structure, whereas stochasticity was likely more important for functional structure. Moreover, the ecological mechanisms shaping individual fish communities switched from limiting similarity to environmental filtering as elevation increased, and the underlying forces at two ends of the elevational gradient became more prominent in the dry season. [ABSTRACT FROM AUTHOR]

Pectocaris species are intermediate- to large-sized Cambrian bivalved arthropods. Previous studies have documented Pectocaris exclusively from the Cambrian Series 2 Stage 3 Chengjiang biota in Yu'anshan Formation, Chiungchussu Stage in SW China. In this study, we report Pectocaris paraspatiosa sp. nov., and three other previously known Pectocaris from the Xiazhuang section in Kunming, which belongs to the Hongjingshao Formation and is a later phase within Cambrian Stage 3 than the Yu'anshan Formation. The new species can be distinguished from its congeners by the sparsely arranged endopodal endites and the morphologies of the abdomen, telson, and telson processes. We interpret P. paraspatiosa sp. nov. as a filter-feeder and a powerful swimmer adapted to shallow, agitated environments. Comparison among the Pectocaris species reinforces previous views that niche differentiation had been established among the congeneric species based on morphological differentiation. Our study shows the comprehensive occurrences of Pectocaris species outside the Chengjiang biota for the first time. With a review of the shared fossil taxa of Chengjiang and Xiaoshiba biotas, we identify a strong biological connection between the Yu'anshan and Hongjingshao Formations. [ABSTRACT FROM AUTHOR]

Maximal light use efficiency (LUE) is an important ecological index of a vegetation essential attribute, and a key parameter of the LUE-based model for estimating large-scale vegetation productivity by remote sensing technology. However, although currently used in different models there still exists extensive controversy. This paper takes the Zoige Plateau in China as a case area to develop a new approach for estimating the maximal LUEs for different vegetation. Based on an existing land cover map and MODIS NDVI product, the linear unmixing method with a moving window was adopted to estimate the time-series NDVI for different end members in a MODIS NDVI pixel; then Particle Swarm Optimizer (PSO) was applied to search for the optimization of LUE retrievals through the CASA (Carnegie-Ames-Stanford Approach) model combined with time-series NDVI and ground measurements. The derived maximal LUEs present significant differences among various vegetation types. These are 0.669 gC·MJ-1, 0.450 gC·MJ-1 and 0.126 gC·MJ-1 for the xerophilous grasslands with high, moderate and low vegetation fraction respectively, 0.192 gC·MJ-1 for the hygrophilous grasslands, and 0.125 gC·MJ-1 for the helobious grasslands. The field validation shows that the estimated net primary productivity (NPP) by the derived maximal LUE is closely related to the ground references, with R2 of 0.8698 and root-mean-square error (RMSE) of 59.37 gC·m-2·a-1. This indicates that the default set in the CASA model is not suitable for NPP estimation for the regional mountain area. The derived maximal LUEs can significantly improve the capability of NPP mapping, and open up the perspective for long-term monitoring of vegetation ecological health and ecosystem productivity by combining the LUE-based model with remote sensing observations. [ABSTRACT FROM AUTHOR]

The Mekong River Basin in Southeast Asia is experiencing extensive hydropower development. Concerns have been raised about the consequences of the development for the ecosystems, livelihoods and food security in the region. The largest planned hydropower dam cascade in the basin, the Lancang-Jiang cascade, is currently under construction and already partly built into the Upper Mekong Basin, China. In this paper we assess the impact of the Lancang-Jiang cascade on downstream hydrology by using a combination of a hydrological model and a reservoir cascade optimization model. The hydrological changes were quantified in detail at the Chiang Saen gauging station in Thailand, the first gauge station downstream from the cascade, and in lesser detail at four other downstream locations in the Mekong mainstream. We found that on average the Lancang-Jiang cascade increased the December-May discharge by 34-155 % and decreased the July-September discharge by 29-36 % at Chiang Saen. Furthermore, the Lancang-Jiang cascade reduced (increased) the range of hydrological variability during the wet season (dry season) months. The dry season hydrological changes were significant also in all downstream gauging stations, even as far as Kratie in Cambodia. Thus the Mekong's hydrological regime has been significantly altered by the Lancang-Jiang cascade, but what the consequences are for ecosystems and livelihoods, needs further study. [ABSTRACT FROM AUTHOR]

The inland aquatic ecosystem in China have been largely influenced by large-scale economic activities and over-exploitation of aquatic resources. Fisheries resource enhancement and conservation activities have been carried out throughout China. These activities include establishing artificial fish habitat and hatchery, releasing juvenile fish to rivers and lakes, forbidding illegal fishing, and setting up natural reserves. The purpose of these activities is to restore the quantity of inland fisheries resources, guarantee sustainable development of fisheries, maintain biological diversity and keep an ecological balance. These activities, conducted with a variety of methods, numerous species, extensive water areas and large scale programs have played an active role in fisheries resource enhancement and conservation. As a consequence the inland water environment has been improved; the biological diversity and fish catch increased, and the social, ecological and economic benefits have been significantly improved. However, problems such as inappropriate technology and nonstandard operations continue to affect fisheries resource enhancement, conservation and ecological stability. This paper reviews the history and practice of inland fisheries resource enhancement and conservation in China, analyzes the existing problems and deficiencies in the activities, and finally make some recommendations on technology and procedures to sustain inland fisheries resources. [ABSTRACT FROM AUTHOR]

Seagrass distribution is a very important index for costal management and protection. Seagrass distribution changes can be used as indexes to analyze the reasons for the changes. In this paper, in situ hyperspectral observation and satellite images of QuickBird, CBERS (China Brazil Earth Resources Satellite data) and Landsat data were used to retrieve bio-optical models and seagrass (Enhalus acoroides, Thalassia hemperichii) distribution in Xincun Bay, Hainan province, and seagrass distribution changes from 1991 to 2006 were analyzed. Hyperspectral results showed that the spectral bands at 555, 635, 650 and 675 nm are sensitive to leaf area index (LAI). Seagrass detection with QuickBird was more accurate than that with Landsat TM and CBERS; five classes could be classified clearly and used as correction for seagrass remote sensing data from Landsat TM and CBERS. In order to better describe seagrass distribution changes, the seagrass distribution area was divided as three regions: region A connected with region B in 1991, however it separated in 1999 and was wholly separated in 2001; seagrass in region C shrank gradually and could not be detected in 2006. Analysis of the reasons for seagrass reduction indicated it was mainly affected by aquaculture and typhoons and in recent years, by land use changes. [ABSTRACT FROM AUTHOR]

Rapid urbanisation and serious environmental problems have led people worldwide to realise the significance of urban planning and management towards a sustainable environment. Beijing was used as a case study to develop a framework and strategies for sustainable development using ecological principles. At the regional level, Beijing-Tianjin agglomeration and Hebei Province are considered together. At the Beijing administrative level, some important measures are put forward for revision of the Beijing Urban Master Plan. At the Beijing plain level, the future spatial structure of Beijing city and the relationship between settlements, green space and transportation are considered, and three basic development patterns are proposed. At the inner district level, the ecological corridor system is suggested, based on ecosystem services. At the selected area level, a comprehensive strategy and key measures for conservation and renewal of old Beijing city core are provided. Once strategies for Beijing urban development are implemented step-by-step, a vision for future development can be achieved. This paper provides considerations for improvement of urban planning and management in China and other countries. [ABSTRACT FROM AUTHOR]

The biodiversity and distribution of arbuscular mycorrhizal fungi (AMF) in different ecosystems and plant communities in China has received increasing interest over the past decades. This has led to a steady increase in the number of scientific papers published on this topic. Studies have surveyed AMF-colonizing rhizospheres of most families of angiosperms, bryophytes, pteridophytes, and gymnosperms. China has about 30,000 plant species (one eighth of the plant species worldwide). A total of 104 AMF species within nine genera, including 12 new species, have been reported in environments such as croplands, grasslands, forests, and numerous disturbed environments. In this paper, we review data published over the past 20 years on AMF community composition and species distribution, the mycorrhizal status of plants, AMF spore communities in different habitats, and germplasm collections in China. Possible future trends in the study of the biodiversity of AMF are also briefly discussed. In particular, the aim of our review is to make some of the recent work published in the Chinese literature accessible to a wider international audience. [ABSTRACT FROM AUTHOR]

With economic development, as well as population growth, the conflict between water supply and demand has become more and more acute in China, and it has been aggravated further by the irrational utilization of water resources: As a result, the deterioration and destruction of the eco-environment have become increasingly serious. In order to effectively protect ecosystems and improve their ecological conditions, many studies on ecological and environmental water requirements (EEWR) have been carried out in China. In this paper, the concept and characteristics of EEWR are addressed, and the main advances of EEWR research and applications in China are summarized in four types of systems including studies on rivers, vegetation, lakes and .wetlands, and groundwater. In conclusion, issues necessary to be studied further in the future are put forward. [ABSTRACT FROM AUTHOR]

Ecological regionalization is a base for rational management and sustainable utilization of ecosystems and natural resources. It can provide a scientific basis for constructing healthy ecological environments and making policies of environmental management. In this paper, based on synthetic analysis of the characteristics of the ecology and environments of China, the principles of ecological regionalization are discussed, and indices and nomenclature of ecological regionalization are proposed. The ecoregions on a national scale are divided. The results show that there are 3 domains, 13 ecoregions and 57 ecodistricts. The present scheme can be used as a framework for ecosystem assessment and management. Based on the ecoregions, measurements of management for forest, grassland, agriculture and wetland ecosystems are recommended. The experience and information can be used within and beyond the national scale for landuse planning, biodiversity conservation and ecosystem restoration. [ABSTRACT FROM AUTHOR]

• Qinling Mountains include unique geography, geology, climate, ecology, and culture. • Regional economic growth and environmental preservation can coexist. • The "life community" promotes eco-friendly civilization and regional growth. China geography, geology, climate, ecology, and cultural landscape are bounded to the north and south by the Qinling Mountains. It has several challenges, including the need to maintain its biodiversity and the need to accelerate economic development. Therefore, the mining area development and ecological community research has strong theoretical and practical significance. In this paper, we studies the Environmental Kuznets Curve, the key influencing factors in the model and a comprehensive strategy of green ecological development based on the three contradictions between environmental protection and mining development in Qinling Mountains. The result of the studies suggested that the solution of resource development, pollution control, and climate change concerns can be accomplished by employing four distinct classifications of enhanced and iterative intelligent, green, and low-carbon comprehensive technological systems. These systems are achievable through the implementation of an independence and self-enhancement strategy in advanced science and technology. Furthermore, the proposed model of Environmental Kuznets curve suggested that there are no significant effect on the sustainable development of mining industry and ecological protection. Moreover, the long-term effects of changes in the ecological and socio-economic environments on a given habitat, an assessment of the sustainability of the ecological environment is more comprehensive and systematic. Thus, the "life community" of ecological preservation and mineral resource development in Qinling is the consequence of the ecologically green civilization and provides the most vigor to the growth. [ABSTRACT FROM AUTHOR]

Introduction: Biodiversity loss poses a significant environmental challenge, particularly in aquatic ecosystems. The advent of environmental DNA (eDNA) sampling technology offers a promising tool for monitoring biological communities with purported high efficiency. Yet, its efficacy compared to traditional sampling methods remains underexplored, especially in fish diversity research. Methods: This study conducted a comparative analysis of fish diversity and distribution across 29 sampling points within the rivers of the Changqing Nature Reserve, Central China, employing both eDNA techniques and traditional sampling methods. Results: A total of 46 unique fish species were identified through this comprehensive approach. eDNA sampling detected 34 species, surpassing the 22 species identified by traditional methods. Interestingly, 10 species were detected by both methods, while traditional methods exclusively identified 12 species not detected by eDNA, and eDNA uniquely identified an additional 24 species. Despite eDNA's broader species detection range, traditional sampling methods typically yielded higher Shannon diversity index values. Both β-diversity indices (Bray-Curtis and Jaccard) and multivariate analyses (NMDS and PCoA) were applied, revealing no significant statistical differences in biodiversity measurement between the two sampling methods. Discussion: The findings suggest that while eDNA sampling excels in identifying a wider range of species, it does not significantly outperform traditional methods in overall biodiversity assessment. By integrating both methodologies, this study demonstrates a more comprehensive and precise assessment of riverine biodiversity, underscoring the benefits of a synergistic approach for enhancing species detection and understanding distribution patterns. The combined methodology notably improves alpha diversity evaluations, particularly regarding Shannon diversity and Berger-Parker dominance. This integrated approach advocates for the amalgamation of data from both eDNA and conventional methods, fostering a robust and accurate biodiversity appraisal. [ABSTRACT FROM AUTHOR]

The Chaoyangopteridae is a clade of azhdarchoid pterosaurs that stands out in China, particularly in the Jehol Biota, as a Cretaceous group of medium-sized and high-crested pterosaurs. Herein, we describe a new species, Meilifeilong youhao gen. et sp. nov., based on two specimens, one tentatively referred to this taxon. This new species represents the most complete and well-preserved chaoyangopterid recorded to date. Along with a set of characters (low premaxillary crest above the nasoantorbital fenestra extending posteriorly, posterior premaxillary process arched and curving posteriorly, a slightly convex sternal articulation surface of coracoid, and a fibular shaft close to proximal articulation strongly arched posteriorly), this species also provides new information both on the unknown palatal region of this clade, and on the rarely preserved (in place) ear portion with stapes. Moreover, M. youhao sheds light on paleoecological aspects, while also giving new information about the taxonomic diversity of this peculiar group of Jiufotang pterosaurs. [ABSTRACT FROM AUTHOR]

Microorganisms are an important component of global biodiversity and play an important role in plant growth and development and the protection of host plants from various biotic and abiotic stresses. However, little is known about the identities and communities of endophytic fungi inhabiting cultivated medicinal plants in the farmland ecosystem. The diversity and community composition of the endophytic fungi of cultivated medicinal plants in different hosts, tissue niches, and seasonal effects in the farmland of Northern China were examined using the next-generation sequencing technique. In addition, the ecological functions of the endophytic fungal communities were investigated by combining the sequence classification information and fungal taxonomic function annotation. A total of 1025 operational taxonomic units (OTUs) of endophytic fungi were obtained at a 97% sequence similarity level; they were dominated by Dothideomycetes and Pleosporales. Host factors (species identities and tissue niches) and season had significant effects on the community composition of endophytic fungi, and endophytic fungi assembly was shaped more strongly by host than by season. In summer, endophytic fungal diversity was higher in the root than in the leaf, whereas opposite trends were observed in winter. Network analysis showed that network connectivity was more complex in the leaf than in the root, and the interspecific relationship between endophytic fungal OTUs in the network structure was mainly positive rather than negative. The functional predications of fungi revealed that the pathotrophic types of endophytic fungi decreased and the saprotrophic types increased from summer to winter in the root, while both pathotrophic and saprotrophic types of endophytic fungi increased in the leaf. This study improves our understanding of the community composition and ecological distribution of endophytic fungi inhabiting scattered niches in the farmland ecosystem. In addition, the study provides insight into the biodiversity assessment and management of cultivated medicinal plants. [ABSTRACT FROM AUTHOR]

Diversity indices (dominance and evenness) and ecological spatial structure (lifestyles and relative abundances) are important features of Changhsingian brachiopod communities prior to the end‐Permian mass extinction (EPME) and could predict temporal and spatial extinction patterns during the EPME. In South China, Changhsingian brachiopod communities show higher diversity than other contemporaneous brachiopod communities in the world and have been reported from a variety of sedimentary environments. In this paper, brachiopods from 18 sections in South China were selected to divide communities and compare their ecological structure. Based on the results of network analysis, cluster analysis and quantitative data from the selected sections, we show that Changhsingian brachiopod communities in South China can be categorized into three assemblages along a marine depth gradient: the Neochonetes–Fusichonetes–Paryphella Assemblage from the shallow‐water clastic‐rock facies, Spinomarginifera–Peltichia–Oldhamina Assemblage from the shallow‐water carbonate platform facies and Fusichonetes–Crurithyris Assemblage from the deep‐water siliciclastic intracontinental basin facies. Compared with communities from carbonate platform facies, the communities from siliciclastic facies were characterized by high dominance, low evenness and low lifestyle diversity, which might be important biotic factors leading to earlier extinctions. After the extinction began in all environments, the whole earliest Triassic brachiopod community was first dominated by Fusichonetes and then by Crurithyris. These patterns of domination and replacement could be explained by morphological and ecological advantages. The domination of these two genera, which were already adapted to the oxygen and food‐limited deep‐water habitat, indicates that the cooler deep‐water environment might have been a relatively less stressed habitat after the beginning of the EPME. This suggests that global warming might be the main trigger among the previously proposed synergistic environmental stresses, while anoxia might not, at least for the beginning of EPME. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heterogeneity index(H) is a structural parameter describing the distribution of species associations. • H is proposed to unveil the species turnover in community in this paper. • Eight lakes exhibit a eutrophication trend with different degrees from the 1950s. • H , species richness, evenness and Jaccard index respond differently to eutrophication. • H can serve as a complementary biodiversity metric to quantify functional diversity. Anthropogenic eutrophication in aquatic ecosystems has had significant negative effects on biodiversity and human wellbeing. Improving our understanding of the ways in which biological communities respond to eutrophication underlies biodiversity conservation, and diversity metrics like species richness and evenness are often used to assess environmental impacts on biodiversity. However, such studies mainly consider overall gain and loss, ignoring species replacement in community succession. This paper combines paleolimnology and network science to propose a heterogeneity index (H) to measure community successions by linking long-term changes in community structure with environmental stress. Eight lakes of different types in the middle and lower reaches of the Yangtze River Basin (MLYB) were selected, and we focused on diatom communities to reconstruct their ecological trajectories after significant anthropogenic impact. The combined results suggested that human impacts have caused eutrophication in each lake since the 1950s, but led to different degrees of impact on the diatom communities. In hypereutrophic lakes, diatom assemblages shifted to high-nutrient tolerance and the proportions of epiphytic-benthic species decreased, while in mildly eutrophic lakes, a switch to mild-nutrient tolerant assemblages occurred in planktonic and epiphytic-benthic species with no change in epiphytic-benthic proportions. The H of diatom communities declined in hypereutrophic lakes, but changed little in mildly eutrophic lakes after the 1950s. Meanwhile, no regular changes in diversity indicators such as richness, evenness and the Jaccard-index occurred with lake eutrophication. The ordered species turnover in nutrient-enriched diatom communities may account for the discrepancies in H and the above indices, such as ordered epiphytic-benthic species being replaced by higher nutrient-tolerant and planktonic species with no necessarily attendant reduction in species richness. By quantifying the alteration of species associations without being influenced by species diversity, the H index effectively reveals the succession of diatom communities, and can therefore serve as a complementary indicator of biodiversity. [ABSTRACT FROM AUTHOR]

Diversity-manipulation experiments suggest a positive effect of biodiversity on ecosystem properties (EPs), but variable relationships between species richness and EPs have been reported in natural communities. An explanation for this discrepancy is that observed richness-EPs relationships in natural communities change with environment and species functional identities. But how the relationships change along broad-scale climatic gradients has rarely been examined. In this paper, we sampled 848 plots of 20 × 30 m2 from boreal to tropical forests across China. We examined plot biomass with respect to environmental factors, tree species richness and functional group identity (FGI, i.e. evergreen vs deciduous, and coniferous vs broadleaf). Variation partitioning was used to evaluate the relative effects of the three classes of factors. We found that, most of the 'effects' (percentage of variation explained) of richness and FGI on forest biomass were shared with environmental factors, but species richness and FGI still revealed significant effects in addition to environment for plots across China. Richness and FGI explained biomass mainly through their shared effects instead of independent effects, suggesting that the positive biodiversity effect is closely associated with a sampling effect. The relative effects of richness, FGI and environment varied latitudinally: the independent effects of environment and richness decreased from boreal to subtropical forests, whereas the total effect of FGI increased. We also found that the slope of richness-biomass relationship decreased monotonically from boreal to subtropical forests, possibly because of decreasing complementarity and increasing competition with increasing productivity. Our results suggest that while species richness does have significant effects on forest biomass it is less important than environmental gradients and other biotic factors in shaping large-scale biomass patterns. We suggest that understanding how and why the diversity-EPs relationships change along climatic gradient would be helpful for a better understanding of real biodiversity effects in natural communities. [ABSTRACT FROM AUTHOR]

The terrestrial Yanliao Biota in northeastern China represents a Jurassic biodiversity hotspot. Abundant and diverse fossils include the oldest known representatives of several groups of plants, invertebrates, and vertebrates that thrived in a forest ecosystem under a humid and warm climate. Since the early 21st century, discoveries associated with the Yanliao Biota have significantly improved our understanding of Jurassic terrestrial ecosystems. However, a robust chronostratigraphic framework is required to calibrate the biota with key evolutionary events and to improve understanding of possible links between evolution and tectonism. In this paper, we report novel 40Ar/39Ar ages for two tuff layers (161.4 ± 0.8 Ma and 161.6 ± 0.6 Ma) positioned directly above the less-studied but salamander fossil-rich beds in Reshuitang, near Lingyuan, Liaoning Province, China. These new age data improve knowledge of the timing of diversification of early salamanders. We also review all reported age data and summarize significant fossils from classic Yanliao outcrops. Our study indicates that the Reshuitang fossil beds were deposited slightly later than the well-known Daohugou fossil beds situated ∼15 km away in Inner Mongolia and somewhat earlier than the Linglongta fossil beds in western Liaoning Province. These findings advance understanding of the Jurassic world during an episode of pronounced climatic warming. • We provide detailed age calibration for the Jurassic Yanliao Biota. • Our study allows us to understand Jurassic terrestrial ecosystems. • A robust chrono-stratigraphy reconstructs the link between life and climate. [ABSTRACT FROM AUTHOR]

The Jehol Biota comprises significant fossils that help to elucidate the evolution of Early Cretaceous terrestrial ecosystems. In this paper, we provide three new zircon U Pb age constraints (124.3 ± 1.5 Ma, 124.9 ± 1.6 Ma, and 121.5 ± 1.4 Ma) from the base to the top of the Jiufengshan Formation (Xinganling Group) at the Naketa section in the north Great Xing'an Range of eastern Inner Mongolia, China, within a succession that contains the typical Eosestheria - Ephemeropsis trisetalis - Lycoptera davidi (EEL) assemblage of the Jehol Biota. Combined biostratigraphic and radio-isotopic dating suggests that the Jiufengshan Formation in the Naketa section corresponds to the upper part of the Yixian Formation and the lower part of the Jiufotang Formation, making it Barremian to earliest Aptian in age. Our findings allow us to test a widely accepted hypothesis about the migration and radiation of the Jehol Biota, and show that these organisms preserved within the lower part of the Jiufengshan Formation reached the Naketa area during the second and third evolutionary stages. The preservation of Jehol elements in the Naketa section provides valuable clues regarding the evolutionary history of the Jehol Biota and its spatiotemporal development. Furthermore, our study allows us to explore possible links between evolutionary processes and concurrent tectonism in the North China Craton, as the timing of this Jehol migration occurred when the tectonic setting changed from a compressional to an extensional regime. • We provide detailed fossil records and robust age for the far north Jehol outcrop. • This study refutes the widely accepted model for the Jehol migration. • Our results test the link between biological radiation and tectonic activity. [ABSTRACT FROM AUTHOR]

Introduction: Soil microorganisms are an important component of soil ecosystems with an indispensable role in forest ecosystems. We analyzed the soil microbial diversity in birch secondary forest formed by natural restoration or artificial reconstruction after interference by burning, clear cutting, and gradient cutting, and the Betula platyphylla Suk undisturbed forest in the Greater Khingan Mountains in China. Methods: Illumina high-throughput sequencing technology was used to analyze the characteristics of the soil microbial community during the restoration process of birch secondary forest caused by the different types of interference. The relationships between bacteria and fungi were analyzed. The gene functions of the soil bacterial community and the ecological functions of soil fungi were predicted using PICRUSt and FunGuild, respectively. Results: At the phylum level, the species and quantity of bacteria were more abundant than that of fungi. At the genus level, no obvious differences in the abundance of bacteria were observed; there were obvious differences in the abundance of fungi. Among the eight sample plots, the artificial larch forest belt had the highest bacterial and fungal alpha diversity, which was slightly higher than undisturbed forest, while the other sample plots were significantly lower. Gradual cutting pure birch forest bacteria and fungi had the highest beta diversity, and artificial larch forest belt bacteria and heavy burn sample plot fungi had the lowest beta diversity. Samples from the cutting and burning sample plots were significantly different from the undisturbed forest at the phylum level of Acidobacteriae, Acidimicrobiia, Mortierellomycetes and Sordariomycetes. We found statistical differences in biomarkers between bacterial and fungal communities in undisturbed forest and artificial larch forest belt and burn sample plots. PICRUSt prediction and FunGuild prediction showed that soil bacterial and fungal communities were rich in gene and ecological functions, respectively. In the microbial network, the stability or anti-interference performance of the fungal community was higher than that of bacteria. Conclusion: Our data reveal the characteristics of the soil microbial community during the restoration process of Betula platyphylla Suk secondary forest under different types of disturbance, which is of great significance for understanding the role of soil microorganisms in the forest ecological cycle. [ABSTRACT FROM AUTHOR]

Globally, natural wetlands have suffered severe ecological degradation (vegetation, soil, and biotic community) due to multiple factors. Understanding the spatiotemporal dynamics and driving forces of natural wetlands is the key to natural wetlands' protection and regional restoration. In this study, we first investigated the spatiotemporal evolutionary trends and shifting characteristics of natural wetlands in the Northeast Plain of China from 1990 to 2020. A dataset of driving-force evaluation indicators was constructed with nine indirect (elevation, temperature, road network, etc.) and four direct influencing factors (dryland, paddy field, woodland, grassland). Finally, we built the driving force analysis model of natural wetlands changes to quantitatively refine the contribution of different driving factors for natural wetlands' dynamic change by introducing the sparrow search algorithm (SSA) and extreme gradient boosting algorithm (XGBoost). The results showed that the total area of natural wetlands in the Northeast Plain of China increased by 32% from 1990 to 2020, mainly showing a first decline and then an increasing trend. Combined with the results of transfer intensity, we found that the substantial turn-out phenomenon of natural wetlands occurred in 2000–2005 and was mainly concentrated in the central and eastern parts of the Northeast Plain, while the substantial turn-in phenomenon of 2005–2010 was mainly located in the northeast of the study area. Compared with a traditional regression model, the SSA-XGBoost model not only weakened the multicollinearity of each driver but also significantly improved the generalization ability and interpretability of the model. The coefficient of determination (R2) of the SSA-XGBoost model exceeded 0.6 in both the natural wetland decline and rise cycles, which could effectively quantify the contribution of each driving factor. From the results of the model calculations, agricultural activities consisting of dryland and paddy fields during the entire cycle of natural wetland change were the main driving factors, with relative contributions of 18.59% and 15.40%, respectively. Both meteorological (temperature, precipitation) and topographic factors (elevation, slope) had a driving role in the spatiotemporal variation of natural wetlands. The gross domestic product (GDP) had the lowest contribution to natural wetlands' variation. This study provides a new method of quantitative analysis based on machine learning theory for determining the causes of natural wetland changes; it can be applied to large spatial scale areas, which is essential for a rapid monitoring of natural wetlands' resources and an accurate decision-making on the ecological environment's security. [ABSTRACT FROM AUTHOR]