The diet of Eneolithic (Copper Age, Fourth millennium cal b.c.) pile dwellers and the early formation of the cultural landscape south of the Alps: a case study from Slovenia

Analyses were performed of plant remains from the Late Neolithic (in Slovenian terminology corresponding to Eneolithic or Copper Age, ca. 4300–2300 b.c.) pile dwelling Hočevarica in the Ljubljansko barje (Ljubljana Moor), Slovenia. This settlement existed between ca. 3650 and 3550 cal b.c. Seeds, fruits, wooden piles, macroscopic charcoal and pollen from the cultural layers were analysed. The remains of domestic plants such as charred grains of Hordeum vulgare (barley), Triticum monococcum, T. dicoccum (einkorn and emmer wheat) and Papaver somniferum (poppy seeds), as well as seeds of weeds such as Chenopodium album-type indicate early cultivation in the area. In addition, numerous remains of nuts and berries, especially of Quercus sp., Cornus mas, Rubus fruticosus and Corylus avellana demonstrate that the gathering of wild plants was an important part of subsistence. Palaeoecological and archaeobotanical data from Hočevarica further suggest that cleared land was used for agriculture and pastures during the Neolithic, and that different wood was cut for construction and for fuel. The species assemblage from Hočevarica is very similar to those recovered from northern Alpine lake dwelling sites, however, several new taxa (e.g. Lathyrus sativus, Vicia sp.) appear in the assemblage. One of the most surprising finds is the seed of wild grape (Vitis vinifera ssp. sylvestris), which are the oldest on-site remains of grapevine from Slovenia.     

低碳经济发展战略研究进展

发展低碳经济已成为国家和区域发展的重要战略。从发展战略的角度,对低碳经济的产生背景、内涵和理论基础等进行了总结和归纳;在此基础上提出了低碳经济发展战略框架研究的主要内容,包括碳政治和碳排放权分配、目标思路、指标体系构建和碳排放的核算;从政策路径、政策工具和政策仿真等方面介绍了低碳经济发展战略的政策研究的主要内容和国内外研究进展。最后指出当前研究的不足之处和未来研究趋向,主要有:低碳经济理论的深入研究,低碳经济战略和政策工具研究,区域低碳经济发展模式研究,低碳经济发展潜力、市场规模和经济技术风险研究,碳减排标准规范的研究和制定。     

Interspecific and intraspecific differences in shoot and leaf lifespan of four Carex species which differ in maximum dry matter production

The effect of N supply on shoot and leaf lifespan was investigated in established stands of four herbaceous Carex species which differed in maximum dry matter production. These species were, in rank order of increasing maximum dry matter production (per unit ground area): Carex diandraC. rostrata. The observed patterns of shoot and leaf turnover were compared with data on leaf characteristics and nitrogen use efficiency indices of these species. There was no consistent difference in shoot production (number of shoots produced per unit ground area) between species with low production and those with high production: Carex diandra (low production) and C. lasiocarpa (high production) had high shoot production, while shoot production in c. rostrata (low production) and C. acutiformis (high production) was much lower. The rank order of the mean lifespan of shoots was: C. diandra. Thus, the lifespan of shoots increased with increasing maximum dry matter production of these Carex species. In all species, increased N supply led to a significant reduction in shoot lifespan. The reduction of shoot lifespans in response to enhanced N supply will result in increased nutrient turnover rates in these species. There was no consistent difference in the number of leaves produced per shoot between low-production and high-production species. C. diandra and C. lasiocarpa had relatively low leaf production, while C. rostrata and C. acutiformis had relatively high leaf production per shoot. Thus, this pattern is opposite to the pattern in shoot production. The rank order of the mean lifespan of leaves was: C. diandra. This implies that the high-production species had longer mean leaf lifespans than the low-production species. Mean leaf lifespan was not significantly affected by enhanced N supply, except in C. diandra, where leaf lifespan decreased in response to enhanced N supply. Shoot lifespans did not show any significant relation with the specific leaf area (SLA, leaf area per unit leaf mass) or the leaf area ratio (LAR, leaf area per unit plant mass) of the species under study. There was, however, a negative relation (r ²=0.71) with the nitrogen concentration in the leaves. Shoot lifespans were positively related (r ²=0.79) with whole-plant nitrogen use efficiency (NUE, dry matter production per unit N-loss) and with the mean residence time of nitrogen (MRT, the average time-span during which a unit of nitrogen is present in the plant) (r ²=0.78), but not with the nitrogen productivity (A, annual dry matter production per unit N in the plant). Leaf lifespan was positively related with the mean residence time of nitrogen in the plants (r ²–0.70). For all the other parameters, there were no significant relations with leaf lifespan. From these results we conclude that: (1) at the stand level, shoot and leaf lifespans are positively related with maximum dry matter production; and (2) shoot and leaf lifespan are important determinants of whole-plant nitrogen economy.     

毛乌素沙地县域典型农、牧户单元生态经济系统能值分析

农、牧户单元生态经济系统作为最基层的生产单位,关系着国家大政方针政策的落实和实施.运用能值理论及其分析方法,选择毛乌素沙地偏牧区的内蒙古自治区乌审旗苏力德苏木典型牧户生态经济系统和偏农区的陕西省榆阳区牛家梁镇典型农户生态经济系统作为研究对象,对两种不同产业偏重区产业模式的能值投入、产出结构状况进行对比分析,结合净能值产出率、能值投资率、环境负荷力、能值功率密度、单位面积生产力、人均能值用量、人均能值占有量、系统生产优势度、系统稳定性指数和系统可持续性指数共10项能值分析综合指标体系,全面系统地对农、牧户单元生态经济系统进行比较研究,定量描述典型农、牧户单元生态经济系统格局及其发展的总体特征.旨在为毛乌素沙地偏牧区和偏农区农、牧户经营层面的产业模式优化及发展提供策略选择.     

亚热带丛枝菌根与外生菌根森林对土壤氮循环的影响

菌根真菌能促进植物获取氮素从而调节土壤氮循环过程,但不同类型菌根影响土壤氮循环的特征尚待更多研究.本试验选择中国亚热带典型次生林植被,设置丛枝菌根(AM)和外生菌根(ECM)树种优势样地,对比分析两种菌根类型森林土壤氮状态的差异,以探究菌根类型影响土壤氮循环的可能作用机制.结果 表明,AM与ECM森林的土壤总氮和铵态氮...     

基于能值分析法的矿区循环经济系统生态效率分析

从系统的角度界定了循环经济和矿区循环经济的内涵,提出了煤炭矿区循环经济系统的基本框架,并以能值分析法为基础构建了矿区循环经济系统生态效率评价指标体系与方法。运用所构建的评价指标体系与方法对山东某矿区进行了研究,得出该矿区循环经济系统2007—2011年5年间的能值效率变化趋势图和生态效率指数趋势图,研究结果与该矿区的实际发展趋势基本一致。表明运用能值分析法所建立的评价指标体系具有较强的有效性,并且对煤炭矿区发展循环经济、提高生态效率具有重要指导意义和参考价值。     

基于CiteSpace中国海洋生态经济的文献计量分析

以CNKI和CSSCI数据库中1980—2017年的1779篇文献为原始数据,基于文献计量分析方法和文献可视化工具,对海洋生态经济领域的研究成果进行信息挖掘。研究发现:(1)海洋生态经济的研究始于1982年,2009年论文发表数量激增成为学术界的研究热点。(2)狄乾斌、高强、殷克东等在海洋生态经济方面做出了大量研究,中国海洋大学、国家海洋局和辽宁师范大学为主要研究机构,研究机构之间合作联系主要以部门和地域联系为主,跨区域和跨部门的合作有待增强。(3)海洋生态经济的研究热点指向"蓝色经济"、"海洋生态系统协调"、"人海可持续发展"等方向。(4)海洋生态经济研究的综合性不断增强,《海洋开发与管理》是海洋生态经济研究刊文量最多的期刊。     

生态是什么—对生态的实质及其表现形式的初步思索

目前,好多生态学术语在社会各界广泛使用,足见生态学知识的普及,但是,却存在许多概念混淆不清而乱用的现象。在我国生态学家马世骏先生建议下,发表周小平同志这篇文章,目的是为了引起对一些生态学术语概念的讨论,澄清一些概念而便于生态学知识更深入地普及。     

基于元指标理论的庆阳区域可持续发展研究

对庆阳各县(区)1990年以来区域可持续发展的时空演变规律及特征进行了综合研究。首先基于元指标理论,构建了庆阳县域可持续发展评价指标体系及综合评价模型,对庆阳各县(区)1990年以来的区域可持续发展状况进行了综合评价及分析。之后根据评价结果,使用重心位移分析法与GIS技术,对庆阳区域可持续发展的空间结构进行了分析。结果表明:1990—2008年,庆阳的区域可持续发展综合水平总体上是在逐渐增强,但这种增强的主要拉动力是经济的快速增长与社会的迅速进步,是以牺牲资源和环境为代价的,这必将最终导致区域可持续发展状况的全面恶化,目前西峰、庆城等部分县区的区域可持续发展综合水平在2005年后已经出现了下降的趋势;1990—2008年,庆阳区域可持续发展持续性重心总体上是向南移动,区域可持续发展协调性重心与综合水平重心的波动较大,反映出各县区的区域可持续发展状况总体上不均衡、不稳定。