天山乌鲁木齐河源区表层雪中含氮离子季节变化特征

通过2004—2007年在天山乌鲁木齐河源1号冰川积累区采集的136个表层雪样品,分析了山岳冰川表层雪中主要含氮离子（NO-3与NH4）的季节变化特征.结果表明,湿季表层雪中的含氮离子浓度一般比干季高,由于湿季NO-3与NH4＋的输入量与流失量均较大,因此湿季浓度波动比干季更强烈.气溶胶与表层雪中的NO-3浓度在干季存...     

Assessing environmental factors in red spruce (Picea rubens Sarg.) growth in the Great Smoky Mountains National Park, USA: From conceptual model, envirogram, to simulation model

This study provides a method for assessing a multiplicity of environmental factors in red spruce growth in the Great Smoky Mountains National Park (GSMNP) of Southeastern USA. Direct and indirect factors in the annual growth increment are first organized into a schematic input-output envirogram (ARIRS), and this information is then used to construct a simulation model (ARIM). The envirogram represents a structured conceptualization of most environmental factors involved in growth, as developed from relevant literature. This interdisciplinary synthesis distinguishes direct vs. indirect factors in growth and takes account of the systems ecology concept that indirect factors may be as important as or more important than direct ones in regulating growth. The ARIRS envirogram summarizes hierarchically organized, within- and cross-scale, local-to-global interactions, and its construction makes it obvious that growth is influenced by many cross-scale spatiotemporal interactions. More research on genecology is still needed to clarify the role of phenotypic plasticity and adaptive capacity in nutrient cycling, global change, and human disturbance.     

1960—2019年秦岭气候带界限的变化研究

受全球变化的影响,温度带边界在空间上的变化呈现出向高纬度方向显著移动的趋势,其中亚热带区空间分布对全球变暖的响应较为敏感,对其边界空间变化特征的研究对于认识全球变化对自然景观的潜在影响具有重要科学意义。基于秦岭及其周边74个气象站点1960—2019年日均气温数据,选取保证率80%的日均温≥10 ℃持续日220天等值线和1月0 ℃等温线为北亚热带北界指标,探讨了近60年气候变暖背景下秦岭气候带界限的变化趋势。研究表明：（1）1960—2019年秦岭日均温≥10 ℃持续日呈显著上升趋势,其变化率为3.268 d/10 a;秦岭1月平均气温呈弱显著上升趋势,其变化率为0.179 ℃/10 a。（2）60年来秦岭北亚热带北界发生了明显的抬升,平均抬升高度约为228.89 m;从经度上看,中段106°~111°E范围内北亚热带北界的变化最为强烈,60年来上升高度达308.81 m,明显高于东西北三段（东段上升165.69 m,西段上升243.33 m,北段上升267.01 m）。（3）60年来秦岭北亚热带过渡带出现了明显的攀升,且向北移动;秦岭以北“跨越式”地出现北亚热带气候格局。气温突变后,秦岭北亚热带过渡带形成从秦岭南坡延伸到秦岭东部,并向北推进向西进入关中平原的格局,秦岭南坡作为北亚热带和暖温带的分界作用有所减弱。随着气候的变暖,秦岭北亚热带过渡带可能部分或整体转变为北亚热带,北亚热带将从秦岭南坡到秦岭北坡呈连续带状分布,北亚热带北界可能会跨越秦岭山脉。     

秦巴山区生态系统服务与居民福祉耦合关系的时空变化

保护生态系统、提高居民福祉是实现联合国2030可持续发展目标的核心内容。在分析秦巴山区生态系统服务与居民福祉时空演化特征的基础上,采用弹性系数揭示了二者的时空耦合关系。研究发现：（1）1990—2018年秦巴山区水源涵养总量、土壤保持总量均呈波动下降趋势,碳储量总量则呈缓慢增长趋势,且各生态系统服务呈不同的空间分异特征。（2）1990—2018年居民福祉呈上升趋势,增幅高达220%,并呈“南高北低”的分布格局。（3）县域尺度上,三种生态系统服务与居民福祉明显不协调发展。其中,水源涵养、固碳服务与居民福祉的耦合关系均以“福祉增—服务减”为主,占比分别为88.75%、62.5%;而土壤保持服务与居民福祉的耦合关系则以“双增”为主,占比为57.5%。此外,各项生态系统服务与居民福祉反向变化区多分布于汉江河谷盆地和秦岭山脉中段。研究结果可为促进贫困山区生态系统服务与居民福祉协调发展提供决策依据。     

“Single-minded,compelling, and unique”: Visual Communications,Landscape, and the Calculated Aesthetic of Place Branding

Place branding strategies play a significant role in the professional composition of landscape imagery, including the depiction of “natural” landscapes. In this paper, Brand Blue Mountains, a brand currently implemented in the Blue Mountains region (Australia), is discursively analyzed. The brand sets out an all-encompassing “Vision” defining the identity, values and personality of the World Heritage listed Blue Mountains landscape, summarized in the tagline Elevate Your Senses. This “vision” is visually translated into a strictly coordinated and copyrighted suite of logos, graphic design, color, fonts and various photographic styles. Analysis reveals that the degree of control that place brand strategists seek to exert over the visual expression of landscape identity is significant. A highly selective narrative of positive nature-based sensory experience is constructed through the holistic application of contemporary visual media. The brands' communications strategy naturalizes and reinforces a particular market-friendly version of place. The framework that brands set for the representation of landscapes overall amounts to an exercise in calculated aesthetics, whereby the form and content of landscape images of various kinds is measured to achieve the greatest market differentiation and impact which technologies allow. The result of this calculated aesthetic system, with its taglines, saturated color, careful composition and magazine-format brevity, is a reduction in the complexity of landscape representations and a perpetuation of nature stereotypes.     

东祁连山土地利用方式对土壤持水能力和渗透性的影响

为了解祁连山东段天祝高寒地区不同土地利用方式对土壤持水能力和渗透性的影响,研究选取天然草地、退耕自然恢复地、燕麦地和多年生草地4种土地利用方式,研究了不同土地利用方式对土壤持水能力和渗透性的影响。结果表明,不同土地利用方式对土壤持水能力和渗透性影响显著。土壤容重大小依次为退耕自然恢复地(1.104 g/cm³)>多年生草地(1.061 g/cm³)>燕麦地(1.011 g/cm³)>天然草地(0.781 g/cm³);总孔隙度为天然草地(68.196%)>燕麦地(60.606%)>多年生草地(58.93%)>退耕自然恢复地(57.5%);土壤最大持水量和土壤稳渗速率天然草地最大(681.966 t/hm²和3.02 mm/min),退耕自然恢复地最小(575.005 t/hm²和1.004 mm/min)。从土壤持水性能和入渗性能来看,4种土地利用方式中天然草地最好,退耕自然恢复地最差,燕麦地和多年生草地土壤持水能力和渗透性能优于退耕自然恢复地。     

Lake variability: key factors controlling mercury concentrations in New York State fish

A 4year study surveyed 131 lakes across New York State beginning in 2003 to improve our understanding of mercury and gather information from previously untested waters. Our study focused on largemouth and smallmouth bass, walleye and yellow perch, common piscivorous fish shown to accumulate high mercury concentrations and species important to local fisheries. Fish from Adirondack and Catskill Forest Preserve lakes generally had higher mercury concentrations than those from lakes in other areas of the state. Variability between nearby individual lakes was observed, and could be due to differences in water chemistry, lake productivity or the abundance of wetlands in the watershed. We found the following factors impact mercury bioaccumulation: fish length, lake pH, specific conductivity, chlorophyll a, mercury concentration in the water, presence of an outlet dam and amount of contiguous wetlands.     

Photolytic degradation of methyl-parathion and fenitrothion in ice and water: Implications for cold environments

Here we investigate the photodegradation of structurally similar organophosphorus pesticides; methyl-parathion and fenitrothion in water (20 °C) and ice (−15 °C) under environmentally-relevant conditions with the aim of comparing these laboratory findings to limited field observations. Both compounds were found to be photolyzed more efficiently in ice than in aqueous solutions, with quantum yields of degradation being higher in ice than in water (fenitrothion > methyl-parathion). This rather surprising observation was attributed to the concentration effect caused by freezing the aqueous solutions. The major phototransformation products included the corresponding oxons (methyl-paraoxon and fenitroxon) and the nitrophenols (3-methyl-nitrophenol and nitrophenol) in both irradiated water and ice samples. The presence of oxons in ice following irradiation, demonstrates an additional formation mechanism of these toxicologically relevant compounds in cold environments, although further photodegradation of oxons in ice indicates that photochemistry of OPs might be an environmentally important sink in cold environments.     

Inbreeding and Loss of Genetic Variation in a Reintroduced Population of Mauritius Kestrel

Abstract:  Many populations have recovered from severe bottlenecks either naturally or through intensive conservation management. In the past, however, few conservation programs have monitored the genetic health of recovering populations. We conducted a conservation genetic assessment of a small, reintroduced population of Mauritius Kestrel ( Falco punctatus ) to determine whether genetic deterioration has occurred since its reintroduction. We used pedigree analysis that partially accounted for individuals of unknown origin to document that (1) inbreeding occurred frequently (2.6% increase per generation; N _eI= 18.9), (2) 25% of breeding pairs were composed of either closely or moderately related individuals, (3) genetic diversity has been lost from the population (1.6% loss per generation; N _eV= 32.1) less rapidly than the corresponding increase in inbreeding, and (4) ignoring the contribution of unknown individuals to a pedigree will bias the metrics derived from that pedigree, ultimately obscuring the prevailing genetic dynamics. The rates of inbreeding and loss of genetic variation in the subpopulation of Mauritius Kestrel we examined were extreme and among the highest yet documented in a wild vertebrate population. Thus, genetic deterioration may affect this population's long-term viability. Remedial conservation strategies are needed to reduce the impact of inbreeding and loss of genetic variation in this species. We suggest that schemes to monitor genetic variation after reintroduction should be an integral component of endangered species recovery programs.     

祁连山北麓生态移民的生计风险与应对策略选择——以武威市为例

生计风险作为移民社会整合的标尺,已成为研究生态移民生计及可持续发展的重要视角。以祁连山北麓的武威市为例,利用Binary Logistic模型分析了移民生计风险对其应对策略的影响机制,以期为制定有效的生计风险防范体系提供科学支撑。结果表明：（1）武威市生态移民的生计类型以非农户为主,纯农户比例不足10%,生计多样化指数仅为1.74且存在显著的区域差异。（2）67.44%的移民面临着多重风险,以经济风险为主,生活开支大、新分棚圈耕地质量差、返贫是主要的风险要素。（3）应对策略主要为向亲朋借钱、银行贷款、外出打工和减少开支,后顾生计则多选择扩大养殖、长期打工和维持现状,不同县区移民的策略选择略有不同。（4）政策、福利和经济风险会显著影响移民对“向银行贷款”“减少开支”及“外出打工”等应对策略的选择,而后顾生计的选择更多受制于生计资本储量,而政策及经济风险的影响较低。移民户的类型对策略选择影响显著,非农型兼业户更倾向于选择“向银行贷款”和“扩大养殖”。