太行山石质山地植被结构优化评价

以太行山石质砂岩区山地植被为研究对象,在对典型植被类型综合调查的基础上,提出了评价山地植被水土保持效益的10项指标,并通过不同植被类型的水源涵养效能指标测定和径流小区泥沙对比分析,认为人工-天然复合植被类型的水土保持效果最好,乔木林最适郁闭度为0．6～0．7。阐述了突出水土保持、水源涵养功能的植被优化结构建设是太行山石质山地植被恢复的根本途径和防护林体系建设的重要内容。     

《1∶5万植被图》填图新模式研究

以太行山摩天岭为样区，以１∶５万地形图为底图，研制出了一种用平面图、剖面图与网络图相结合的绘制植被图的“双面图法”。用该法绘制的植被图，其正面为平面图和剖面图，背面为相对应的网格图。该图能对每种植被层片（或类型）和植物种的自然分布进行科学定位，能反映出各区域的土壤类型，并能显示出小区域的气候因子。     

Influence of dietary feathers on the fecal microbiota in captive Arctic fox: Do dietary hair or feathers play a role in the evolution of carnivorous mammals?

Hair and feathers are composed of keratin and are indigestible, inalimental and unpalatable for carnivores. However, carnivores often ingest hair and feathers during feeding or when grooming. We hypothesized that ingestion of hair and feathers changes species diversity and relative abundance of bacteria in the gut of carnivores. To test this hypothesis, we added disinfected poultry down feathers to the normal diet of captive Arctic foxes (Alopex lagopus). We then used fluorescently labeled terminal restriction fragments (T‐RFs) to examine changes in fecal bacterial diversity and abundance. The results showed that the number of bacterial species increased significantly after feather ingestion, but that total abundance was unchanged. This demonstrated that addition of disinfected feathers to the diet stimulated increased production among less abundant bacteria, resulting in a balancing of relative abundance of different bacterial species, or that some newly‐ingested microbial species would colonize the gut because a suitable microhabitat had become available. This implies that the overall production of bacterial metabolites would be made up of a greater range of substances after feather ingestion. On one hand, the host's immune response would be more diverse, increasing the capacity of the immune system to regulate gut microflora. On the other hand, the animal's physiological performance would also be affected. For wild animals, such altered physiological traits would be subjected to natural selection, and, hence, persistent geographic differences in the character of ingested feathers or fur would drive speciation.     

Green roof vegetation type affects germination and initial survival of colonizing woody species

Green roofs provide a number of valuable ecosystem services compared to conventional roofs, but may require yearly maintenance. Trees and other woody plants that persist on the roof may damage or overload shallow-substrate green roofs and their removal is a standard maintenance procedure. The germination potential of colonizing species may differ depending on the vegetation surrounding them. The aim of this study was to determine whether the germination of colonizing tree species (Picea glauca and Ulmus glabra) will vary depending on which plant species form the established vegetation seeds land in. To determine germination success, survival, and seed capture ability of the plant canopy, tree seeds were added either directly to the growing medium or atop the plant canopy, in replicated monocultures of 14 species native to Nova Scotia. When seeds were added directly to the soil, no significant difference was detected between the monocultures for germination success or survival for U. glabra or P. glauca. However, when the seeds were added atop the plant canopy, percent germination of U. glabra was significantly higher in Carex argyrantha green roof modules. Overall, sod forming graminoids showed higher germination of U. glabra. The number of seeds reaching the soil was typically lower in vegetation with a denser canopy. This study demonstrates that some vegetation repels colonizing tree species by reducing ground contact. Although these effects differed according to tree species, non-vegetated substrates enhanced seedling persistence. Additionally, the majority of tree seeds that germinated failed to survive a single growing-season on shallow-substrate green roofs.     

橄榄坝电站对下游曼厅大沙坝河段影响研究

通过建立澜沧江橄榄坝-曼厅大沙坝河段物理模型,研究电站清水下泄对下游曼厅大沙坝河段的影响。在满足模型试验的相似要求前提下,冲刷坑的平面总体形态呈现泪滴形。在开始阶段冲刷坑的深度变化较快,达到一定深度之后,深度变化减小,最终趋于稳定,此时冲刷就达到了平衡状态。丁坝最大冲刷深度和最大冲刷宽度的纵向位置基本一致。     

基于Lokta-Volterra模型的农业生产托管两主体共生演化研究

基于共生理论构建托管农户与托管服务组织两主体共生演化Lokta-Volterra动态模型,探讨不同共生系数下两主体共生演化的均衡结果,并在此基础上利用数值仿真模拟两主体共生演化模式。研究表明：托管农户与托管服务组织在不同共生环境下会形成寄生共生、偏利共生和互惠共生三种共生模式,且三种模式具有动态演化的特征;托管农户与托管服务组织共生演化的均衡结果取决于二者间的共生系数;托管农户与托管服务组织在互惠共生模式下才能达到最优的发展状态。最后,基于模型结果提出相应的政策建议。     

施氮对关中地区冬小麦农田土壤呼吸的影响及基于植被指数的估算模型

为探寻不同施氮量对农田土壤呼吸（R_S）的影响并快速准确估算R_S,以关中地区冬小麦为研究对象,观测了5种施氮量下冬小麦农田R_S的变化,研究了环境因子（土壤温度、土壤湿度）及作物因素（叶面积指数、地上部生物量、SPAD值）对于R_S的影响,建立了适用于关中地区土壤温度与植被指数下的农田土壤呼吸估算模型。设置秸秆还田下的5种施氮量处理,分别为传统施氮量SN200（200 kg·hm^-2）、优化施氮量SN150（150 kg·hm^-2）、60%优化施氮量SN120（120 kg·hm^-2）、50%优化施氮量SN100（100 kg·hm^-2）以及不施氮肥SN0（0 kg·hm^-2）。结果表明：不同施氮量下R_S随生育期推进均表现为先升高再降低的趋势,同时添加氮肥促进了R_S排放。各处理观测期内R_S的均值为：SN200（3.68 μmol·m^-2·s^-1）>SN150（3.40 μmol·m^-2·s^-1）>SN120（3.06 μmol·m^-2·s^-1）>SN100（2.70 μmol·m^-2·s^-1）>SN0（2.21 μmol·m^-2·s^-1）。不同施氮量下冬小麦冠层近红外波段反射率在拔节期和抽穗期差异明显,反射率从高到低依次为SN200>SN150>SN120>SN100>SN0,而在灌浆期和成熟期差异不大。土壤温度显著影响了R_S（P<0.01）,土壤湿度与R_S没有显著相关关系（P0.05）。叶面积指数、地上部生物量、SPAD值和植被指数均与R_S呈显著相关关系（P<0.05）。通过多种模型评估,建立基于植被指数和土壤温度的最佳农田土壤呼吸估算模型,显著高于基于土壤温度的单因子模型,模型精度可达到0.6以上（n=120）。     

银川地区地下水环境演化

本文在总结银川地区地下水监测点的多年水位和水质资料的基础上,研究地下水水位的动态变化和水质随时间的变化。分别对潜水和第一承压水的水位埋深及水质进行分析,结果表明:潜水水位动态变化受外界影响较大,由于人类的合理调控,盐化水域面积缩小,土壤盐渍化面积减小;承压水的水位动态受开采的影响,集中开采区第一承压水降落漏斗范围扩大,并逐渐引起水化学场发生改变。     

Static home-based versus dynamic mobility-based assessments of exposure to urban green space

There is growing interest in urban green space exposure estimated dynamically by accounting for individuals’ mobility during daily life. We aimed to explore if daily green space exposure estimates based on individuals’ mobility substantially differ from static home-based exposure estimates, and to examine potential effect modification by personal (sex and work status) and temporal (weekends versus weekdays) characteristics. To assess the association between daily exposure to urban green space, we used home address and time-activity data collected from 1911 participants in western New York, US, using their GPS-enabled mobile phones. We abstracted both individuals’ home address based (home-based) and daily time activity based (mobility-based) green space exposures from the Normalized Difference Vegetation Index (NDVI). Then, we assessed the association between mobility-based and home-based exposure estimates using linear mixed effect regression models with subject-specific random effects. We also explored whether this effect was modified by individual-level characteristics, including work status and sex, as well as whether assessments took place on weekdays versus weekends. We found that daily dynamic exposure to urban green space based on individuals’ mobility was not substantially different from static exposure estimates based on one’s residence, but that there were statistically significant effect modifiers. Specifically, the correspondence between mobility-based and home-based exposure to green space was relatively lower for employed compared to unemployed participants, whereas their correspondence during weekends increased compared to weekdays. Our findings suggest that there is a strong correspondence between mobility-based and home-based exposure to urban green space, but that their associations are modified by personal and temporal characteristics. Further research is needed to confirm our finding for general population in other settings, such as different seasons and other regions.     

Enhancing pollination ecosystem service in urban green areas: An opportunity for the conservation of pollinators

The rapid growing urbanization is one of the main threats to urban biodiversity and the ecosystem services (ES) that they provide. Pollination is one of the most affected ES in urban areas mainly due to the decline in urban green areas (UGAs) and other factors derived from urbanization itself. Considering this and the already existing global pollinator crisis, the aim of this work is the evaluation of urban green infrastructure as an opportunity for pollinator conservation. For that purpose, the ornamental vegetation of a medium-sized Mediterranean city (Granada, south-eastern Spain) was determined. The floral origin, phenology and floral traits of the conforming species and the pollinator species that they attract were analysed. Additionally, NMDS analysis were performed in order to determine if the “Pollination Syndromes” are a useful tool to actually predict the pollinator group attracted to a certain plant species. It was found that UGAs have huge potential for pollinator conservation as the major part of its ornamental species have an entomophilic pollination strategy. However, there is an imbalance in the availability of flower resources throughout the year. Hence, the addition of species flowering out of the main flowering season would be advisable in order to get a continuous supply of floral resources for pollinators. A current disproportion in the potentially attracted pollinator groups was also found out, being bees the predominantly attracted ones. However, results showed that the “Pollination Syndromes” are a tool with limitations at the moment and needs to be used with considerations. Thus, the specific plant-pollinator relationship should be determined through field work in each case-study. Further studies considering key factors such as urban connectivity and fragmentation would be desirable to ensure a comprehensive management for urban pollinators.