Research and application of GEP: China’s experience in natural capital accounting

In 2013, for raising the awareness of policymakers and researchers on the economic value of ecosystem services, GEP (Gross Ecosystem Product) was proposed by Chinese scholars. As a new attempt at ecosystem services evaluation, GEP has been widely accepted in China and is often used to reveal the effectiveness of regional ecological protection and the relationship between humans and nature. However, there is currently a lack of a systematic review of GEP research. In this study, we found that: 1) GEP can reflect the overall situation of ecological environment and service quality, and help decision-makers and managers formulate and implement sustainable development strategies and ecological protection policies. 2) The contradiction between the depletion of global ecosystem capital and the development of people’s livelihood continues to intensify. About 68.7% of developing countries are facing a “low-low development (low GEP and low GDP)” model. 3) We have constructed the path model of the GEP working system and the path model of ecological protection compensation mechanism in China. The GEP accounting system of “from point to area, from top to bottom”, the parallel evaluation strategy of GDP and GEP and the comprehensive ecological compensation system of “vertical and horizontal combination” implemented can be popularized to countries all over the world

Millennium tree-ring reconstruction of drought variability in the eastern Qilian Mountains, northwest China

Knowledge of natural long-term drought variability is essential for water resource management and planning, especially in arid and sub-arid regions of the world. In the eastern Qilian Mountains of China, long-term drought variability based on high-resolution proxy records such as tree-ring data are still scarce to date. Here we present a new tree-ring chronology from the eastern Qilian Mountains which provides a valuable 1,002-year record (1009–2010 CE) of drought variability. The new reconstruction of June–July 5-month scale standardized precipitation and evapotranspiration index is the first millennium tree-ring estimate of past climate developed in the eastern Qilian Mountains. The record shows that this region has experienced several persistent droughts and pluvials over the past millennium, with significantly drier climate during the fifteenth century and dramatic wetting since the nineteenth century. The low frequency generally agrees with other nearby studies based on both tree-ring data and other proxy data

Cold Atmospheric-Pressure Plasma Caused Protein Damage in Methicillin-Resistant \u3ci\u3eStaphylococcus aureus\u3c/i\u3e Cells in Biofilms

Biofilms formed by multidrug-resistant bacteria are a major cause of hospital-acquired infections. Cold atmospheric-pressure plasma (CAP) is attractive for sterilization, especially to disrupt biofilms formed by multidrug-resistant bacteria. However, the underlying molecular mechanism is not clear. In this study, CAP effectively reduced the living cells in the biofilms formed by methicillin-resistant Staphylococcus aureus, and 6 min treatment with CAP reduced the S. aureus cells in biofilms by 3.5 log10. The treatment with CAP caused the polymerization of SaFtsZ and SaClpP proteins in the S. aureus cells of the biofilms. In vitro analysis demonstrated that recombinant SaFtsZ lost its self-assembly capability, and recombinant SaClpP lost its peptidase activity after 2 min of treatment with CAP. Mass spectrometry showed oxidative modifications of a cluster of peaks differing by 16 Da, 31 Da, 32 Da, 47 Da, 48 Da, 62 Da, and 78 Da, induced by reactive species of CAP. It is speculated that the oxidative damage to proteins in S. aureus cells was induced by CAP, which contributed to the reduction of biofilms. This study elucidates the biological effect of CAP on the proteins in bacterial cells of biofilms and provides a basis for the application of CAP in the disinfection of biofilms

Extended xylogenesis and stem biomass production in Juniperus przewalskii Kom. during extreme late-season climatic events

Late-season extreme climatic events induced variations in wood density and extended growth for more than a month in 2016 in Juniperus przewalskii Kom. growing on the Northeastern Tibetan Plateau, suggesting extraordinary growth resilience of the species in response to short extreme events over the cold and arid region. Context Monitoring xylem formation (xylogenesis) during extreme meteorological events helps assessing climate change impacts on tree growth. Aims For better insight into tree-growth responses, here we compare the intra-annual formation of annual ring with and without intra-annual density fluctuation in J. przewalskii in a cold and arid environment on the Northeastern Tibetan Plateau. Methods Cambial phenology and xylogenesis observations of five mature trees during the 2016 intra-annual density fluctuation growth ring and the five-preceding year (2011–2015) were used for comparison. The frequency of population level occurrence of intra-annual density fluctuation in 2016 was examined on additional 50 randomly selected trees. Results The return of precipitation in conjunction with warm temperatures after summer drought promoted the growth resumption in 64% of our study trees, resulting in the observed intra-annual density fluctuation. These trees experienced a growing season 1 month longer than trees without intra-annual density fluctuation. The extended growth period resulted in a 17% increase in stem biomass in trees that experienced intra-annual density fluctuation. Conclusion Our results highlight the extraordinary resilience of J. przewalskii trees in response to extreme climatic events in the cold and dry conditions of the Tibetan Plateau

Response of Biodiversity, Ecosystems, and Ecosystem Services to Climate Change in China: A Review

Climate change is having a significant impact on the global ecosystem and is likely to become increasingly important as this phenomenon intensifies. Numerous studies in climate change impacts on biodiversity, ecosystems, and ecosystem services in China have been published in recent decades. However, a comprehensive review of the topic is needed to provide an improved understanding of the history and driving mechanisms of environmental changes within the region. Here we review the evidence for changes in climate and the peer-reviewed literature that assesses climate change impacts on biodiversity, ecosystem, and ecosystem services at a China scale. Our main conclusions are as follows. (1) Most of the evidence shows that climate change (the increasing extreme events) is affecting the change of productivity, species interactions, and biological invasions, especially in the agro-pastoral transition zone and fragile ecological area in Northern China. (2) The individuals and populations respond to climate change through changes in behavior, functions, and geographic scope. (3) The impact of climate change on most types of services (provisioning, regulating, supporting, and cultural) in China is mainly negative and brings threats and challenges to human well-being and natural resource management, therefore, requiring costly societal adjustments. In general, although great progress has been made, the management strategies still need to be further improved. Integrating climate change into ecosystem services assessment and natural resource management is still a major challenge. Moving forward, it is necessary to evaluate and research the effectiveness of typical demonstration cases, which will contribute to better scientific management of natural resources in China and the world

Guaranteed rendezvous for cognitive radio networks based on cycle length

© 2017 IEEE. Rendezvous is a blind process establishing a communication link on common channel between a pair of nodes in the cognitive radio networks. How to reach rendezvous efficiently and effectively is still an open problem. In this work, we propose a guaranteed rendezvous algorithm for cognitive radio networks, based on the prime cycle length. When the cycle lengths of the two nodes are coprime, the rendezvous is guaranteed in Ti ∗Tj +δ time slots, where Ti is the cycle length of node i and Tj is that of node j. When Ti = Tj, combining with the deadlock checking and the binary ID of each node, each node will independently change its cycle length bit by bit, by which the rendezvous can still be guaranteed in T0i ∗ Tc + [log max{IDi, IDj}] ∗ (Ti0 ∗ Ti1 + δ) time slots under all the possible time skew δ [O, Ti), where Tc is some constant, and T0 and T1 are two prime numbers defined for Ti. We conduct simulations on three metrics to demonstrate the efficiency of the proposed method

Guaranteed rendezvous algorithms for cognitive radio networks

© 2013 IEEE. Rendezvous is a blind process establishing a communication link on a common channel between a pair of nodes in cognitive radio networks. We propose two guaranteed rendezvous algorithms for cognitive radio networks under both single-radio and multi-radio scenarios with an asynchronous setting. For single-radio scenario, each cycle length is a prime number associated with a channel hopping sequence. The rendezvous can be guaranteed as long as the IDs of the two nodes are different. For multi-radio scenario, we propose a cycle length and rotation based rendezvous algorithm. Each node generates a channel hopping sequence with only one cycle length. Then these radios of each nodes rotate on the generated sequence with different rotation numbers at each hopping cycle. The rendezvous between two nodes is guaranteed as long as they have different cycle lengths or the same cycle length with different number of rotations. We conduct simulations on three metrics and the results show that the proposed algorithms outperform the existing ones

Removing Biological Trends From Tree-Ring Series: Testing Modified Hugershoff Curves

The performance of the Hugershoff curve on fitting the growth trends of tree-ring series was tested using ring-width series with different starting years. The fitted values tend to be biased by tree-ring series close to pith, a phenomenon that was referred to as the ‘‘start-fitting problem’’. We determined three parameters with specific biological age-related meanings for the Hugershoff growth curve, i.e. the maximum growth, the maximum slope and the maximum changing ratio of slopes. A set of modified Hugershoff curves with different starting years was proposed to mitigate the start-fitting problem. Behavior of the modified Hugershoff curves on tree-ring series standardizations was tested and discussed. The ‘‘end-fitting problem’’ suggests that deviations in one interval could bias the fitted values of other time periods by using the Hugershoff curve.This item is part of the Tree-Ring Research (formerly Tree-Ring Bulletin) archive. For more information about this peer-reviewed scholarly journal, please email the Editor of Tree-Ring Research at [email protected]

Seasonal patterns in the leaf C:N:P stoichiometry of four conifers on the northeastern Tibetan Plateau

Research into leaf traits, especially carbon (C), nitrogen (N), and phosphorus (P), are essential for understanding the nutrient uptake strategies and ecosystem functions, such as the rates of photosynthesis, transpiration, and nutrient intake in plants. However, seasonal patterns of leaf C:N:P stoichiometry in arid and semiarid forest ecosystems remain unclear. In this study, temporal scale monitoring was conducted on four conifer species (Picea wilsonii, Pinus tabuliformis, Picea crassifolia, and Juniperus przewalskii) within the Qilian Mountains to determine the seasonal patterns of leaf C:N:P stoichiometry and their driving forces. The seasonal patterns of the leaf N and P contents were asynchronous among the species. The C content and C:N and C:P ratios in the leaves in Tulugou (relatively wet and fertile) were lower than those in Langchaigou (extremely infertile and dry), whereas the N and P contents in the leaves displayed an inverse pattern (p < 0.05). The results confirmed that the leaf economics spectrum gradually transitions from high resource acquisition to high resource conservation as the environmental stress increased. Additionally, the leaf N and P contents were found to be positively correlated with the precipitation and soil water content during the growing seasons (p < 0.01), whereas the soil temperature negatively impacted the leaf N and P contents (p < 0.01). A two-way analysis of variance indicated that the species was the main driving factor of variation in the leaf C:N:P stoichiometry in the four conifers. The redundancy analysis revealed that soil properties explained 50.9 % of the total variability in the leaf stoichiometry, with the soil N pool having the strongest effect on the leaf traits. Overall, our results indicated that the tree species and soil N pools were the key driving factors affecting the leaf stoichiometry of the conifers, and the trees adapted to the changing environment through a trade-off in the leaf functional traits. These findings provide a temporal and spatial perspective for understanding how the leaf functional traits of conifers respond to environmental changes in arid and semi-arid montane forest ecosystems