Natural Resource Access Rights and Wrongs: Nontimber Forest Products Gathering in Urban Environments

This article uses research about non-timber forest products (NTFP) gathering in Seattle, Washington, USA to examine how people gain access to natural resources in urban environments. Our analysis focuses on gathering in three spaces: parks, yards, and public rights of way. We present a framework for conceptualizing access, and highlight cognitive mechanisms of access associated with foragers’ internal moral judgments about harvesting. Key findings are: (1) internal moral calculations about whether it is right or wrong to harvest a particular NTFP in a particular place are an important but previously unacknowledged mechanism governing resource access; and (2) these calculations may help prevent over-harvesting of NTFPs, which are common pool resources, in urban environments where social and environmental conditions lend themselves to a de facto situation of open access. Our findings suggest that voluntary codes of conduct may be the best way to manage NTFP access in cities.     

盐度对滨海湿地土壤碳库组分及稳定性的影响

从土壤有机碳含量和活性组分出发,分析了湿地土壤碳库组分对盐度变化的响应特征。同时分析了土壤有机碳3种稳定机制,评述了土壤碳稳定性与盐分中主要离子的博弈。并在基于研究滨海湿地碳固定与稳定的基础上,提出了土壤碳稳定与营养元素循环的相互作用机制研究、土壤碳稳定与微生物及酶学机制的关系研究、借助稳定同位素技术多要素多过程耦合研究等科学问题展望。以期为了解未来中国海平面上升背景下湿地碳截获潜力的可能演变趋势及其应对策略,为发展和完善中国湿地土壤碳循环理论奠定科学基础。     

Mesoscale and Microphysical Characteristics of a Double Rain Belt Event in SouthChina on May 10–13, 2022

A second rain belt sometimes occurs ahead of a frontal rain belt in the warm sector over coastal South China,leading to heavy precipitation. We examined the differences in the mesoscale characteristics and microphysics of thefrontal and warm sector rain belts that occurred in South China on May 10–13, 2022. The southern rain belt occurred in anenvironment with favorable mesoscale conditions but weak large-scale forcing. In contrast, the northern rain belt wasrelated to low-level horizontal shear and the surface-level front. The interaction between the enhanced southeasterly windsand the rainfall-induced cold pool promoted the persistent growth of convection along the southern rain belt. The con vective cell propagated east over the coastal area, where there was a large temperature gradient. The bow-shaped echo inthis region may be closely related to the rear-inflow jet. By contrast, the initial convection of the northern rain belt wastriggered along the front and the region of low-level horizontal shear, with mesoscale interactions between the enhancedwarm-moist southeasterly airflow and the cold dome associated with the earlier rain. The terrain blocked the movement ofthe cold pool, resulting in the stagnation of the frontal convective cell at an early stage. Subsequently, a meso-γ-scalevortex formed during the rapid movement of the convective cell, corresponding to an enhancement of precipitation. Therepresentative raindrop spectra for the southern rain belt were characterized by a greater number and higher density ofraindrops than the northern rain belt, even though both resulted in comparable hourly rainfalls. These results help us betterunderstand the characteristics of double rain belts over South China.     

夏季青藏高原湿池变化特征及其与降水的关系

利用1979—2011年ERA-Interim的月平均再分析资料和全国气象台站观测资料,通过小波分析、合成分析和相关分析等多种统计分析方法,分析了夏季青藏高原湿池的基本特征,定义了能较好表征夏季青藏高原湿池强度变化的特征指数,并揭示了夏季青藏高原湿池强弱异常时的大气环流特征及其与中国夏季降水的关系。主要结论为:夏季高原上湿池特征非常明显,2个湿中心分别位于高原东南部和西南部。高原湿池强度指数有明显的阶段性变化特征,以4 a左右和6 a左右的变化周期为主。夏季高原湿池偏强(弱)年,南亚高压、西太副高、高原季风、低层风场以及整层水汽输送等均有显著变化,进而对我国夏季降水产生重要影响。     

西太平洋暖池热含量与南海夏季风强度的关系

为了进一步明确西太平洋暖池热含量对南海夏季风强度的影响,利用1948~2012年日本气象厅(japan meteorological agency,JMA)逐月的海温资料、Hadley中心的海表面温度(Sea Surface Temperature,SST)资料以及NCEP/NCAR再分析资料,分析比较了南海夏季风强度与热带太平洋上层海洋热含量和SST的关系;探讨了海洋热含量影响南海夏季风强度的机制。结果表明:(1)相比于西太暖池SST,西太暖池上层海洋热含量是南海夏季风强度更好的预测因子;(2)前期冬春季的西太平洋暖池热含量与南海夏季风强度呈现显著的正相关,尤其在3月,二者相关系数最大;当暖池热含量偏高(低)时,西太平洋副热带高压偏弱(强),赤道印度洋出现异常反气旋(气旋),印度洋上空的Walker环流分支偏强(弱),南海越赤道气流增强(减弱),最终使得南海夏季风强度偏强(弱)。     

黄海暖流源区附近温盐结构及其季节变化

为探究不同季节下黄海暖流在源区的状态,利用韩国海洋数据中心(Korea Oceanographic Data Center)发布的水文数据,对黄海暖流源区附近温盐结构及其季节变化进行了分析。结果表明:年平均状态下对马暖流在济州岛东南存在向西向入侵的趋势,其入侵存在明显的季节变化:秋季最强,冬、春季开始减弱,夏季最弱。济州岛西侧,约在33°30′N、125°30′E处存在一支伸向西北的高盐舌,该高盐舌盐度同样具有明显的季节变化:冬季最强,春季开始减弱,夏季降至最低,秋季盐度开始缓慢回升。黄海区盐度的变化要滞后于对马暖流区盐度变化。冬季朝鲜沿岸水南下入侵程度最强,能到达34°N以南的位置。     

滨海复杂地层超深旋挖钻孔灌注桩质量问题改进技术

钻孔上部存在较厚的淤泥质软弱地层,旋挖钻孔灌注桩施工时应在孔口设置泥浆缓存池,始终保持钻孔内的泥浆面高度。护壁泥浆的性能是保证钻孔质量的基础,施工时必须加强对泥浆性能指标的监测,必要时应采用泥浆净化装置对泥浆进行净化。选择合理的护筒埋设长度和钻进参数,不仅可以保证施工质量,还可大幅降低施工成本。     

Mid-Holocene variability in the marine C reservoir age for northern coastal Papua New Guinea

Changes in oceanic radiocarbon (¹⁴C) reservoir ages through the deglaciation and Holocene can provide important information on ocean circulation as Earth's climate warmed. Here, we present reservoir ages for the western tropical Pacific that span the mid-Holocene transition from less to more frequent El Niño events. Reservoir ages were calculated using paired U–Th and conventional ¹⁴C dating of eight individual fossil coral samples from Koil and Muschu Islands, northern coastal Papua New Guinea (PNG). AMS ¹⁴C and MC-ICPMS U–Th dating of additional samples from six of the fossil corals were used to confirm the TIMS U–Th and conventional ¹⁴C ages. The combined results show average reservoir ages of 185±30 ¹⁴C yr (n=4) for 7220–5850 yr BP compared to 420 ¹⁴C yr for a modern coral from Muschu Island. From 5850 to 5420 yr BP reservoir ages increase to modern values. The relatively young reservoir ages from 7220 to 5850 yr BP are best explained by greater influx of well-equilibrated sub-tropical water from the southern branch of the South Equatorial Current (SEC). This is consistent with strengthening trade winds (facilitating air–sea exchange) and a more northerly position of the Intertropical Convergence Zone thought to have occurred at this time. The transition to more modern-like reservoir ages from 5850 to 5420 yr BP suggests modern oceanic circulation patterns were established during this interval. The onset of modern El Niño activity around this time would have served to enhance the intrusion of ¹⁴C-depleted equatorial waters via the south equatorial branch of the SEC. Overall, the changes in reservoir age presented here for the western tropical Pacific suggest that Holocene changes in the El Niño–Southern Oscillation state of the tropical Pacific resulted in reorganisation of oceanic circulation in this region.     

Phylogenetic analysis of bacterial community in deep-sea sediment from the western Pacific “warm pool”

A depth profile of bacterial community structure in one deep-sea sediment core of the western Pacific ＂warm pool＂ （WP） was investigated and compared with that in a sediment sample from the eastern Pacific （EP） by phylogenetic analysis of 16S rDNA fragments. Five bacterial 16S rDNA clone libraries were constructed, and 133 clones with different restriction fragment length polymorphism （RFLP） patterns were sequenced. A phylogenetic analysis of these sequences revealed that the bacterial diversity in a sample from the WP was more abundant than that in the EP sample. The bacterial population in the sediment core of WP was composed of eight major lineages of the domain bacteria. Among them the γ-Proteobacteria was the predominant and most diverse group in each section of WP sediment core, followed by the α-Proteobacteria. The genus Colwellia belonging to γ-Proteobacteria was predominant in this sample. The shift of bacterial communities among different sections of the WP sediment core was δ-, ε-Proteobacteria, and Cytopahga-Flexibacteria-Bacteroides （CFB） group. The ratios between them in the bacterial communities all showed inversely proportional to the depth of sediment. The sequences related to sulphate reducing bacteria （SRB） were detected in every section. The bacterial community structure in this sediment core might be related to the environmental characteristics of the surface seawater of the western Pacific WP.     

印度洋-太平洋暖池季节变化及其相应的大气环流形式

首先通过对英国大气科学数据中心海表面温度资料和Levitus随深度变化的海温资料的分析,给出了印度洋-太平洋暖池季节变化的详细描述.另外,利用NCEP/NCAR再分析大气资料中的风场数据,采取将水平风场分量分解为无辐散分量和无旋分量的方法,分析了相应于暖池季节变化的大气环流形式.得到了这样的结论：第一,印度洋-太平洋暖池的位置随季节变化南北移动;暖池面积在北半球的5月和9月达到两个极大值;无论就海表面温度还是深度而言,该暖池分别存在一或两个强度中心.第二,尽管印度洋-太平洋暖池中间被南亚大陆所间隔,但是暖池上空对流层大气运动对于暖池的季节变化却是作为一个整体响应的.