岑溪市森林资源生态系统服务功能及价值评估 — 以岑溪市中林林业发展有限公司森林资源为例

本研究选取岑溪市中林林业发展有限公司 2445. 33hm2森林资源的 4个龄组类型作为研究对象,采用 2021年 度森林资源规划设计调查的基本数据,从固碳释氧、涵养水源、净化空气、杀菌、土壤保持、生物多样性保护这 6 个方面 13 个指标来评估其生态系统服务价值。 结果表明:2445. 33hm2森林资源生态系统服务总价值高达 1. 16亿元,其中固碳释氧 价值总量为 3349. 46万元,涵养水源价值总量为 1309. 49万元,净化空气价值总量为 1077. 47万元,杀菌总价值为 72. 38 万元,土壤保持价值总量为 3296万元,生物多样性保护价值总量为 2445. 35万元;在 4种龄组类型中, 中龄林的生态价值 总量为 4612. 22万元,幼龄林的生态价值总量为 2921. 69万元,近熟林的生态价值总量为 2726. 09万元,成熟林的生态价 值总量为 1290. 14万元,各龄组林分的生态价值与其面积和蓄积呈正相关性。 此次生态价值核算结果为当地森林生态价 值实现机制和林业可持续发展提供了一定参考依据。     

Does diversified environmental regulation effect the foreign direct investment inflows and technological innovation? A three-stage least square approach

Foreign direct investment (FDI) inflows have been significantly impacted by environmental regulation (ER). This study is aiming at analyzing the ER effect on the FDI inflows. By using the data of 2008–2018, we use Three-stages least square (3SLS) method to assess the connection between FDI inflows and ER. The study results reveal that in Chinese industries, technological innovation (TI) is stipulated by the ER, and as a result, FDI has been engrossed. The results further reveal that TI has been enhanced by capital penetration, and a positive effect is perceived between TI and FDI. The findings of our study also show that there is a significant association between foreign capital (FC) inflows and TI, which indicates that technological policies are effective and advanced environmental policies would intensify the relevant policies between firms. Based on the study outcomes, this research proposes some policy suggestions for constructing a attuned policy system of environmental protection and FDI by regulating the implementation of conforming strategies.     

Experiences and Skills for Establishment of Rat Model of Myocardial Ischemia and Reperfusion

The establishment of rat model of myocardial ischemia and reperfusion is a very sophisticated experimental process. During animal experiments, beginners always meet with troubles inevitably. This paper have conducted a great deal of this type of experiments for years, and intend to share some experiences and lessons with colleagues.     

间伐强度对华北落叶松人工林植被物种多样性的影响

在北京市延庆县营盘村附近低山,对造林密度为5151株/hm2的23a生华北落叶松人工林,设置4个间伐强度处理。5a后,通过比较林下植被组成、外貌及多样性的变化,研究不同间伐强度对华北落叶松人工林群落稳定的影响。结果表明,间伐改变了群落的生活型谱,随间伐强度增大,地面芽植物和地下芽植物所占比重上升,而高位芽植物却呈相反的趋势。间伐强度不同,华北落叶松林下植被的建群种各异。间伐可提高林下植被的丰富度和多样性,这种效应以弱度间伐最为明显。间伐对草本层物种丰富度、多样性影响较灌木层大,而对林下植被分布均匀性影响甚微。因此,及时对郁闭林分进行合适强度的间伐,促进林下植被发育,是实现华北落叶松人工林可持续发展的有效途径。23a初植密度5151株/hm2的华北落叶松选择58.75%左右的间伐强度林下植被发育最优     

泥鳅早期形态发育研究

【目的】为了解泥鳅仔、稚鱼生长发育规律,同时为规模化苗种培育工作提供基础数据。【方法】通过对0~23日龄的泥鳅仔稚鱼连续取样,系统观察了泥鳅仔稚鱼各发育分期的形态特征和发育时间。【结果】研究结果表明,在水温(19.5~22)℃下,泥鳅胚胎发育时间需要24~28 h。初孵仔鱼平均体长为3.04 mm,鱼体透明,全身无黑色素,口和消化管均未形成;初孵仔鱼至孵化后6日龄为卵黄囊期仔鱼,4日龄仔鱼开口,仔鱼进入混合营养期;7~9日龄为前弯曲期仔鱼,7日龄仔鱼卵黄囊吸收完毕,此时完全进入外源营养期;10~14日龄为弯曲期仔鱼;15~22日龄为后弯曲期仔鱼;至23日龄,出现细小圆鳞,已与成鱼具有相似的外观和生活习性,此时进入稚鱼期。【结论】研究泥鳅早期形态发育将为泥鳅自然资源繁殖保护和养殖业苗种培育提供理论依据。     

Differentiation of nitrogen and microbial community in the littoral and limnetic sediments of a large shallow eutrophic lake (Chaohu Lake,China)

Purpose

Nitrogen (N) is one of the major elements causing eutrophication in freshwater lakes, and the N cycle is mainly driven by microorganisms. Lake littoral zones are found to be “hotspots” for N removal from both the basin and receiving waters. However, the environmental factors that drive the distribution of microorganisms are diverse and unclear. Here, we examined the differentiation of nitrogen and microbial community between the littoral and limnetic sediments to explore their interactions.

Materials and methods

Sediment samples were collected in the littoral and limnetic zones of Chaohu Lake in winter (ca. 7 °C) and autumn (ca. 22 °C). Abundances of the bacterial and archaeal genes amoA (ammoxidation), nirS and nirK (denitrification), hzsB (anaerobic ammonium oxidation; anammox), and nrfA (dissimilatory nitrate reduction to ammonium; DNRA) were measured via quantitative real-time polymerase chain reaction (qPCR). Clone libraries were constructed for further phylogenetic analysis to study the community composition.

Results and discussion

We observed significant higher concentration values in terms of sedimentary NH₄⁺-N and NO₃^?-N in the limnetic zone than littoral zone (p?<?0.05; n?=?12). In general, abundance values of the above six genes in the littoral zone were all higher than those in the limnetic zone, while higher in winter (7 °C) than in autumn (22 °C) (p?<?0.05; n?=?6). The spatial heterogeneity had the most significant effect on the distribution of ammonia-oxidizing archaea (AOA) and anammox bacteria abundance. Both temporal (temperature) and spatial heterogeneity affected the abundance of ammonia-oxidizing bacteria (AOB). The variation in the abundance of denitrifying bacteria and DNRA bacteria mainly reflected the temporal (temperature) heterogeneity.

Conclusions

The six N-cycle-related microorganisms were affected by different environmental factors and presented different distribution patterns. The lower nitrogen content and the higher microbial abundance and diversity showed that the littoral zone was the “hotspot” of N-cycling-related microorganisms in a large, eutrophic, and turbid lake. It is suggested that increasing the area and restoring the ecological function of the littoral zone was effective and significant in eutrophic lake management.

     

基于ModelBuilder的垦造水田耕地质量等别评价

为快速准确的掌握土地整治工程前后耕地质量等别的时空变化信息,提升耕地质量等别评价实践工作效率,以连平县隆街镇沐河村垦造水田项目区为研究区域,将传统农用地分等方法与ModelBuilder建模方法融合,构建了垦造水田工程项目背景下的耕地质量等别快速评价框架体系.研究以连平县2016年耕地质量等别更新成果作为数据基础,结合...