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Purpose Soil carbon (C) storage plays an important role in the mitigation of atmospheric CO2 emission. Soil C pools under different vegetation are distinct and need to be investigated. However, there are still large quantities of data shortages, which should be remedied by field and systematic studies. Materials and methods Soil was collected at 0–10 cm depth from subtropical natural vegetation and plantations both in southeast China and southeast Queensland, Australia, respectively. Soil samples were assayed for soil organic C; organic N and inorganic N; and mineralization of SOC; total C, N, and P; and pH. Results and discussion Our results suggested soil C concentrations in natural vegetation ranged from 6.25% to 9.20%, whereas soil C concentrations in plantations ranged from 1.08% to 2.69%. No significant differences were found among vegetation along altitudinal gradients, whereas plantations with different tree species had different soil C concentrations, being higher in broadleaf-species plantations than in coniferous-species plantations. But there were no differences in soil C between single-species plantations and mixed-species plantations. Soil C concentrations in plantations were correlated with soil moisture, soil pH and dissolved organic C concentrations; Whereas soil C concentrations in natural vegetation were significantly correlated with soil moisture, soil pH and NO3− concentrations. Conclusions These results can contribute to the remedy of data shortages and provide the data necessary for model projections and informed decisions in the future.

The extracts of petroleum ether, methanol, ethyl acetate and ether from Taxus chinensis var. mairei seeds were analyzed by GC-MS, and relative contents were determined using a normalized method. 56 peaks were obtained from extracts of spermoderm and 79 peaks from endosperm of T. chinensis var. mairei. Among these peaks, 37 chemical constituents were gained, and 24 compounds of which were identified (64.86%). There were 35 chemical constituents with content more than 1%, accounting for 94.59% of the total of all chemical constituents. 32 peaks were gained from petroleum ether extract, and 7 peaks were identified (21.88%) with content more than 1%. 36 peaks were gained from methanol extracts, and 14 peaks were identified (38.89%), 13 of which with content more than 1%, accounting for 92.86% of the total of all chemical constituents. 34 peaks were gained from ethyl acetate extracts, while 10 peaks were identified (29.41%) with content more than 1%. 33 peaks were gained from aether extracts, and 11 peaks were identified (33.33%). T. chinensis var. mairei seeds have various bio-active ingredients and a higher value for development and utilization as a medicinal plant.

Seeds of Taxus chinensis var. mairei are known for their deep dormancy that can be broken by a procedure involving variable temperature stratification. Changes of ultrastructure in seed embryo of T. mairei during stratification were investigated with a scan electricity microscope and a transmission electricity microscope. After 4 months of warm stratification, the following cytological changes were observed: an enlargement of the embryo and cotyledon. Two months of warm stratification following the cold treatment induced embryonic cells and apical meristems continued to divide. An abundance of electro-dense matter and a small amount of starch grain and mitochondria appeared, and the lipids in the embryonic cell gradually degraded. After four months of cold stratification treatment, one or two distinct nucleoli in the shoot apical meristem cells were observed, embryo increased in volume, the cotyledon became stretched, the lipids in the embryonic cell disappeared, the number of mitochondria increased, and the Golgi bodies appeared. We concluded that warm stratification with alternating temperatures increased the growth of embryos by cell expansion and enlargement. Cold stratification may induce a response to gibberellic acid and initiated cell division resulting in the release of physiological dormancy and subsequent germination of T. mairei seeds. Key words: Taxus chinensis var. mairei, seed, scan electricity microscope (SEM), transmission electricity microscope (TEM).

Different soil water and nutrient conditions affect soil microbial ecology and changes in soil moisture and nutrients reflect changes in the soil environment over time.In this study,the utilization of carbon sources by the soil microbial community under slash pine,hoop pine(Araucaria cunninghamii) and kauri pine(Agathis australis) was investigated with manipulated soil moisture contents using MicroRespTM methods.Results showed that under slash pine,carbon utilization was highest in soil at 60% water holding capacity(WHC) and lowest at 40% WHC.The high carbon utilization at 60% WHC is likely due to respiration from anaerobic microorganisms.Conversely,the hoop and kauri pine showed similar results with carbon utilization at its highest in soil at 20% WHC and lowest at 40% WHC.L-Malic acid,oxalic acid and L-Lysine were the carbon resources resulting in the highest microbial utilization intensity.The difference in carbon utilization efficiency between the forest types was obvious at 20% and 60% WHC where the carbon utilization under slash pine was lower than hoop and kauri pine at 20% WHC and higher than hoop and kauri pine at 60% WHC.However,excluding L-Arginine and L-Lysine,the order of carbon utilization in soils with 60% WHC was hoop pineslash pinekauri pine.The utilization of carbon sources in soils at 40% WHC was lower than 1μg CO2 g-1 h-1 and the differences between forest types were not obvious.Owing to the high carbon utilization capacity of the microbial communities at 60% WHC,the soil microbial diversity was analyzed using the Shannon diversity index,Shannon evenness index and Simpson diversity index.The differences in values were not significant between forest types but diversity values were highest under hoop pine.This indicates that the decomposition of hoop pine needles is higher,resulting in a higher soil organic matter content and thus higher microbial growth and metabolism.The microbial metabolic diversity of the different forest soil types was analyzed by PCA.Results showed that it was not easy to distinguish between the metabolic diversity of the different soil microbial communities because the complex forest carbon sources result in vast differences in metabolic function.Principal component scores for each factor from analysis of microorganisms on 15 different carbon sources showed that the soil microbial community related to amino acids(PC1) and sugars(PC2),which explained 33.80 and 24.13% of the variance,respectively,were also sensitive to changes in forest soil microbial communities.RDA analysis was performed on each variable independently to maintain the contribution rate of forest types in different combinations of variables for the statistical characterization of a single variable,and the merits of the decision variables were revealed.On soil microbial metabolic characteristics and soil properties,RDA analysis showed that the utilization of L-Alanine,L-Arginine,D-(+)-Glucose and N-Acetyl-glucosamine was greatly influenced by pH in kauri pine.Utilization of Citric acid,L-Malic acid and γ-Amino butyric acid were influenced by total phosphorus in hoop pine,and D-(+)-Fructose,Citric acid and L-cysteine-HCl were influenced by water,total nitrogen and total carbon in slash pine.

In this paper, K nearest neighbor algorithm is improved in fingerprint information matching in WiFi indoor positioning system. Because the original K nearest neighbor algorithm ignores the relationship between the neighboring points, it doesn’t improve matching accuracy, and its positioning accuracy is not better. There is no effective treatment group sample points, matching time is greatly increased. In this paper, we study a modified K nearest neighbor algorithm in the application of WiFi indoor positioning. Because K neighbor points are given different weights according to certain rules, the matching accuracy is improved before matching method. And because of using grouping pretreatment of the sample space, the time of position matching accuracy is reduced. Therefore the positioning precision is improved.

Map information and sensor information is considered to be an effective way to assist indoor wireless location. Wireless location combined with map information and Sensor information can solve many problem such as positioning point cross the wall, falling into the wrong room. In this paper, a new indoor map matching algorithm was proposed based on particle filter. The indoor positioning system could be considered as non-linear system, so Non-parametric Monte Carlo (Monte Carlo) simulation method could achieve recursive Bayesian filtering, at the same time, the indoor GIS data, and sensor information, wireless location information was incorporated into the weight value of the particles to revise the observations constantly. Many experiments show that the indoor positioning accuracy is improved.

Most of the phone has been configured IMU currently, includes an acceleration sensor and an electronic compass. In this paper, using the pedestrian dead reckoning algorithm based accelerometer and electronic compass composition IMU to assist indoor positioning. Detection walking step length and state. Currently detect direction of motion requires the user wear or hand in IMU with a fixed posture. To address this issue, using the terminal gesture recognition algorithm in the third quarter. When pedestrian walking on the same direction, the angle walking forward and walking backward was the same. To address this issue, using pedestrian movement direction detection method based on the differential cross-correlation of the acceleration in the fourth quarter. Based on the above, the article conducted experiments in Section V and the result shows that the proposed method can effectively detect pedestrian movement forward and backward state, the average accuracy of the detection results is 85.67 %.

The distribution characteristics of soil nutrient of bamboo forests in Jiangxi Province 6 main producing bamboo counties were studied. The results showed that the soil nutrient contents decreased with depth. The soil organic matter contents in Sanzhualun (SZL) and YangLing bamboo forest were obvious higher than others. The 0-10 cm content available nitrogen in SZL and total nitrogen in Fengxin Jindong (FXJD)was the highest. The soil total nitrogen and available nitrogen of 10-30 cm and 30-50 cm in SZL were the highest, while these of 10-30 cm were the lowest in Tonggu Paibu (TGPB) and Tonggu Daixi (TGDX) and that of 30-50 cm in SZL. The differences of soil available phosphorus were a few in TGDX and Yifeng Shuangfeng (YFSF), and the changes were 3.33-4.06 mg kg-1 and 3.86- 4.42 mg kg-1. The soil available potassium of 0-10 cm and 10-30 cm layer in SZL bamboo forest were respectively 60.33 mg kg-1 and 35.78 mg kg-1 and both were the highest. In 30-50 cm soil layer, the soil available potassium content was the highest in TGDX, while the lowest in YFSF. Analysis of variance showed that the differences of soil organic matter and available nitrogen content were very significant between the layers of forests. The differences of total nitrogen and available potassium of 10-30 cm and 30-50 cm were very significant. There were no significant differences of soil available P and surface available K content.