从中全新世古森林探讨生物多样性变化

本文从历史植物地理学的角度、根据川西南山地冕宁县沉黄沼泽地层中发掘出中全新世以来保存完好的大量古森林遗迹资料，通过多学科综合性研究证实，中全新世“沉黄古森林”距今约７０００多年，是由４４科、５５属、７３种森林植物组成，以铁杉为主要建群种，林内混生有多种常绿和落叶针阔叶树种。从该森林的演变和种类组成变化得知，在距今４５００年～２８００年间，铁杉和阔叶树种数量减少，云南松数量增加，杉木已从森林中消失；距今２８００年后铁杉进一步减少，云南松显著增加，黄杉、华山松、油杉、桦木、木荷、桤木逐渐从森林中消失；距今２０００年左右，铁杉和雪松从森林中消失。目前该地区森林已演变成云南松林或松栎混交林。森林生态环境演变大致分为４个阶段：（１）温暖多雨阶段（距今７０００年以前）；（２）温暖湿润阶段（距今７０００年～４５００年）；（３）温暖潮润阶段（距今４５００年～２８００年）；（４）温暖干燥阶段（距今２８００年以来）。由上可见，沉黄中全新世古森林及生态环境的演变，提供了这一森林生态系统在时间和空间上物种多样性变化的实例。     

中国历史时期的森林文化及其发展

详述了森林文化的概念及内涵，系统总结了森林文化在不同历史时期的特征及相应历史背景。     

基于研学视角的广州钱岗古道保护与发展策略研究

在粤港澳人文湾区建设背景下,南粤古驿道与文化旅游已成为发展重点和热点,文化遗产与旅游的融合发展研究对推动古驿道的活化利用具有重要意义。在剖析古驿道与研学旅游相关研究及融合发展交互关系的基础上,选取广州钱岗古道为研究对象,针对古道沿线资源和保护发展困境,以研学旅游为切入点,提出拓展多元需求的研学群体、打造空间复合的研学旅游基地、完善功能齐全的配套服务设施、发展古驿道“文化+旅游”产业链、复原和整合历史文化资源、营造类型多样的主题活动游线 6 个方面的古驿道保护与发展策略。     

An unholy disease in the Holy Land: The history of anthrax between the Jordan River and the Mediterranean Sea (1909–2012)

The history of recorded cases of anthrax in human beings and animals from 1909 to 2012 in the area between the Jordan River and the Mediterranean Sea is reviewed. The disease was endemic until the middle of the 20th century, but the incidence decreased thereafter, with only sporadic cases from the 1980s onwards. Human cases have not been diagnosed in the region since 1984 and the number of episodes of animal disease has reduced to less than one per year. This decline is mostly due to the disruption of the infective cycle by improved veterinary control, including vaccination, treatment and outbreak management. A policy of reactive vaccination for 10 years of affected herds and herds grazing in their proximity has been applied. No new outbreaks have been observed in such herds after the cessation of vaccination, despite continued grazing on the same sites, so it is assumed that spore survival in such areas is shorter than 10 years. This is independent of the soil composition, which is calcareous throughout most of the relevant area. However, reemergence of anthrax, even after decades, has occurred following disturbance and heavy rainfall.     

Promoting connectivity between priority freshwater sites for conservation in intermittent hydrological systems

1. Systematic conservation planning in freshwater ecosystems faces multiple challenges because of the dynamic nature of rivers and their multiple dimensions of connectivity. In intermittent hydrological systems connectivity is functional when water is available, allowing the exchange of aquatic individuals between isolated freshwater ecosystems. Integrating these isolated systems in their hydrological context is essential when identifying priority areas for conservation, in order to try to minimize the propagation of threats into target water bodies (management units) from the surrounding landscape.
2. Here, the use of a systematic planning approach is demonstrated to identify a set of priority management units to preserve freshwater biodiversity in an arid system of fragmented water bodies immersed in a landscape subject to a range of impacts.
3. Twenty-six water-dependent taxa from 59 mountain rock pools (gueltas) of three southern Mauritanian mountains were used as a case study. A conservation planning tool (marxan ) was used to find priority conservation areas to integrate intermittent hydrological systems in their hydrological context, promote connectivity, and minimize the downstream propagation of threats. Three types of connectivity were analysed: (i) no connectivity, (ii) connectivity between gueltas, and (iii) connectivity between gueltas and sub-catchments.
4. Considering different types of longitudinal connectivity affects the number and spatial allocation of the priority gueltas selected, and the conservation status of the gueltas and their upstream areas. Incorporating connections between gueltas and upstream locations in the modelling resulted in the selection of gueltas in areas with a low human footprint and in the increased connectivity of the solutions.
5. The results obtained revealed important locations for local biodiversity conservation, and the method presented can be used when assessing the propagation of potential waterborne threats into isolated management units. The framework developed allows connectivity to be addressed in conservation planning. It can be replicated in regions with similar isolated habitats that connect through intermittent hydrological systems and can also be applied to lateral and vertical hydrological connectivity.

     

六安瓜片绿色名茶可持续开发研究

历史名茶—六安瓜片被列为中国十大经典绿茶之一，是与其独特的生长环境、制作工艺和优良的品质分不开的。目前，六安瓜片开发在取得初步成就的同时，也存在着质量标准难以控制、生产成本偏高、品牌保护力度不够等问题。因此，必须改进六安瓜片的生产工艺，降低其生产成本，全面实施无公害茶目标，扶持龙头企业，打造知名特色品牌，才能确保六安瓜片绿色名茶的可持续发展。     

DYNAMIC ANALYSIS OF ASYMMETRIC FRAME-SHEAR WALL SYSTEM BY STAGE CONTINUITY METHOD

The lateral structures of frame-shear wall system are simplified into bending beams and shear beams which stiffness can vary in different stages along the building height. The three-dimension stiffness matrix and mass matrix are deduced, and the characteristic equation is established to calculate the tortuous free vibration of the asymmetric system. The method is simple and has satisfactory precision, and it is easily fulfilled in micro-computers.     

Time and scale of gully erosion in the Jedliczny Dol gully system, south-east Poland

Key catchments of the Roztocze loess area in south-east Poland have a great potential of revealing the history of long-term soil erosion and changes in land use. The knowledge of how and when soil erosion took place in the past helps one understand the impact of land use changes on the landscapes [Bork, H.-R., 1989. Soil erosion during the past Millennium in Central Europe and its significance within the geomorphodynamics of the Holocene. Catena 15, 121–131]. The Jedliczny Dol gully system near the town Zwierzyniec in south-east Poland was investigated by using detailed field stratigraphy and radiocarbon dating of charcoal and wood.In connection with new settlements which were established between the 14th and 16th centuries, arable land was cultivated and forests were used much more intensively. As a consequence, the loess soils were strongly eroded during heavy rainfalls. Up to 4 m of colluvial sediments were deposited in the gully system during the 15th and/or 16th centuries. The thickness of the colluvial sediments indicate severe erosion which might be related to excessive timber exploitation for the local glass and iron production. With the foundation of the so-called Ordinariat Zamoyski at the end of the 16th century, some parts of the area were presumably reforested. High pressure on the land at the beginning of the 19th century enabled a second main phase of gulling before 1900.Since 1890 at the latest, almost the whole catchment is used as a forest, however, concentrated runoff on compacted forest roads can still be high after heavy rainfalls.In loess areas soil erosion caused by intensive land use, triggered by heavy rainfalls, can change the landscape drastically. These changes will continue to influence how catchments react, even if land use gets less intensive again. This knowledge should be considered regarding future, sustainable land use and recent changes in land use in the south-eastern Polish loess regions.     

Crossing the thresholds: human ecology and historical patterns of landscape degradation

In discussions of landscape sensitivity, human activities have generally been regarded as external forces contributing to landscape change, with a focus on the impacts of cultivation methods, fertiliser practices, grazing pressures and atmospheric pollution. However, there has been comparatively little study undertaken that integrates physical and social systems in a historic context to explain the basis of human activity in sensitive landscapes. Where such attempts have been made, the manner of common land management has figured prominently, with ‘tragedy of the commons’ concepts used to explain land degradation and to provide a foundation for policy response. This has also been the case in Southern Iceland and in this paper we assess the extent to which common land domestic grazing pressures were the primary external force causing soil erosion and land degradation during the period of occupation from ca. 874 AD. We first provide field observation of soil erosion, temporally defined by tephrochronology, to highlight the extent of land degradation during this period. The ‘tragedy of the commons’ explanation of degradation is then assessed by evaluating historic documentary sources, and by environmental reconstruction and modeling of historic grazing pressures. These analyses indicate that regulatory mechanisms were in place to prevent overgrazing from at least the 1200s AD and suggest that there was sufficient biomass to support the numbers of domestic livestock indicated from historic sources. We suggest that failure to remove domestic livestock before the end of the growing season and an absence of shepherding were more likely to contribute to land degradation than absolute numbers. Lack of appropriate regulation of domestic livestock on common grazing areas can be attributed to limited cultural knowledge of changing and rapidly fluctuating environmental conditions.     

历史时期西北地区季节性灾害对农业技术选择的影响

为了降低灾害风险,有效控制自然灾害的发生发展,历史时期西北地区在长期的农业生产实践中选择了一系列行之有效的技术措施进行防灾、抗灾和减灾,对促进西北地区社会经济发展起到了重要的作用。研究历史时期的农业减灾技术对于当今的抗灾减灾仍有借鉴意义。