脆弱性研究进展:从理论研究到综合实践

从20世纪60年代脆弱性概念提出到21世纪脆弱性逐渐成为一门独立的新科学,脆弱性已成为评价地区发展状况的依据以及衡量未来发展规划的判据。基于国内外脆弱性研究文献的回顾和总结,回顾了脆弱性概念起源与发展,梳理了脆弱性评价的定性和定量方法,科学评述了21世纪以来脆弱性研究的新进展:评价方法创新、多尺度精细评价、多源数据挖掘、关键要素阈值界定、人为活动影响和脆弱性演化机理综合研究。研究发现21世纪以来脆弱性进展迅速,主要特点为多元化、多角度、精细化和综合化,表现为评价数据和方法的多元化;横向空间对比和纵向时间序列的多角度分析;多尺度精细评价;关键要素阈值与演化机理综合研究。未来,脆弱性研究应完善脆弱性概念框架和理论体系,关注耦合系统脆弱性过程与机制,探究脆弱性驱动因素和演化机理,科学界定脆弱性关键要素阈值,挖掘和提取多源遥感数据信息,开展系统脆弱性动态评价和时空分析,实现脆弱性定量评价与综合实践,最终满足国家和地区可持续发展战略的需要。     

基于生物量的塔里木河下游胡杨(Populus euphratica)生态服务价值评估

胡杨是塔里木河下游荒漠河岸林的重要组成部分,研究塔里木河下游胡杨生物量及生态服务价值变化特征,可以为塔里木河下游生态输水的效益评估提供科学依据。以塔里木河下游胡杨为研究对象,采用实地调查采样与遥感解译分析相结合的方法,评估了不同年份胡杨地上生物量特征,并结合遥感方法提取不同年份胡杨面积,估算了不同年份胡杨的生态服务价值。结果表明:(1)胡杨主要分布在离河道0—700 m的范围内,此范围内的生物量占总生物量的90%以上;在离河道700 m以外,胡杨的生物量不足10%。英苏断面胡杨平均生物量最高,阿拉干断面次之,依干不及麻与喀尔达依断面胡杨生物量较低。(2)2000年,胡杨单位面积平均生态服务价值为78.96元/hm~2,2010年为177.14元/hm~2,2016年为313.55元/hm~2;胡杨总服务价值在2000年为43.24×10~4元,2010年为93.00×10~4元,2016年为184.27×10~4元。(3)2016年胡杨的有形服务价值为22.74×10~4元,无形服务价值为161.53×10~4元,胡杨的无形生态服务价值为有形生态服务价值的7.1倍。生态输水对胡杨生物量与服务价值具有显著的影响,输水效益十分显著。     

Biological traits of Epitrix papa (Coleoptera: Chrysomelidae: Alticinae), a new potato pest in Europe,and implications for pest management

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Cold tolerance of the invasive larch casebearer and implications for invasion success

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明清时期江南私家园林景点题名中的竹文化研究

中国古典园林中竹文化的研究对于弘扬我国优秀传统文化和提升现代园林中竹景观的文化内涵都具有重要意义,现有研究主要集中在竹的空间营造、种植形式等方面,而从品题学角度对传统私家园林中的竹文化系统研究得还比较薄弱。以明清时期江南私家园林的景点题名为研究对象,采用文献查询和实地调研相结合的方法,对江南园林中的竹景点、常见题名意象及其所表达的精神内涵进行研究。结果表明明清时期竹在江南私家园林景点题名中应用非常普遍,常见的题名意象主要表达了道家的隐逸思想、儒家的比德思想、佛教的心无思想和民俗吉祥思想。从中可以看出,明清时期文人阶层天人合一的哲学观、三教并存的宗教观和雅俗共赏的审美观。     

不同抗凝策略对急性多发性创伤伴下肢骨折患者DVT和肺栓塞发生率的影响

目的:探讨不同抗凝策略对急性多发性创伤伴下肢骨折患者下肢深静脉血栓(DVT)和肺栓塞发生率的影响。方法:将2017年1月～2017年12月我院收治的200例急性多发性创伤伴下肢骨折患者按照随机数表法分为观察组和对照组,每组各100例。对照组予以低分子肝素钙,观察组予以利伐沙班。随访1月,比较两组患者DVT、肺栓塞的发生情况,术前、术后1 d、术后5 d血栓弹力图指标、血液流变学的变化,术中失血量、术后引流量及者用药不良反应的发生情况。结果:①随访1月,观察组DVT的发生率显著低于对照组(P0.05),两组肺栓塞的发生率对比差异无统计学意义(P0.05);②术后1 d时,两组R时间、K时间均短于术前(P0.05),α角、MA值、中切全血粘度、低切全血粘度、血浆粘度均高于术前(P0.05),但两组以上指标组间对比差异无统计学意义(P0.05);术后5 d时,两组R时间、K时间均长于术前1 d时(P0.05),α角、MA值、中切全血粘度、低切全血粘度、血浆粘度均低于术前1 d时(P0.05),且观察组以上指标改变幅度均大于对照组(P0.05);③两组术中失血量、术后引流量、不良反应发生率对比差异无统计学意义(P0.05)。结论:利伐沙班和低分子肝素钠均有利于改善急性多发性创伤伴下肢骨折患者血液流变学和凝血功能,但前者效果更佳,更有利于降低DVT的发生风险。     

Unnatural Contexts Cause Honey Bee Guards to Adopt Non‐Guarding Behaviours Towards Allospecifics and Conspecifics

Context plays an important role in a discriminator's ability to make appropriate recognition decisions, such as accepting what is acceptable and rejecting what is not acceptable. Previously it was shown that in both honey bees and stingless bees, discriminating workers (guards) make more errors towards conspecific non‐nestmates when the guards are removed from the natural hive entrance. However, it may be that guards, in addition to making incorrect recognition decisions, also may adopt non‐guarding behaviours. Here, we tested honey bee guards in two contexts (natural versus unnatural) against five types of introduced arthropods (conspecific nestmates and non‐nestmates; allospecific wasps, beetles and woodlice), which should be rejected without error. We scored a guard's response as accept, reject, avoid and ignore. Total errors significantly increased from natural to unnatural contexts. Specifically, guards were significantly more likely to make an acceptance error, guarding and accepting both conspecific and allospecific non‐nestmates, in the unnatural context. Importantly, guards were significantly more likely to adopt a non‐guarding behaviour in the unnatural context, which usually involved ignoring or avoiding, where a guard makes contact but then immediately retreats, the introduced arthropod. Overall, these data demonstrate the context is important. Removing a guard from the home that it protects elicits either incorrect discrimination or, additionally, a complete lack of discriminator behaviour altogether.     

Habitat fragmentation and species richness

In a recent article in this journal, Fahrig (2013, Journal of Biogeography, 40 , 1649–1663) concludes that variation in species richness among sampling sites can be explained by the amount of habitat in the ‘local landscape’ around the sites, while the spatial configuration of habitat within the landscape makes little difference. This conclusion may be valid for small spatial scales and when the total amount of habitat is large, but modelling and empirical studies demonstrate adverse demographic consequences of fragmentation when there is little habitat across large areas. Fragmentation effects are best tested with studies on individual species rather than on communities, as the latter typically consist of species with dissimilar habitat requirements. The total amount of habitat and the degree of fragmentation tend to be correlated, which poses another challenge for empirical studies. I conclude that fragmentation poses an extra threat to biodiversity, in addition to the threat posed by loss of habitat area.     

一类带时滞竞争模型的周期解

研究了来源于水生种群植化相克的模型,提出了带时滞的半线性抛物系统．用上下解方法讨论了抛物方程组周期解存在性的原理,利用特征函数构造所提出抛物系统的上解,给出了正周期解存在的充分条件．