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81.
Anthropogenic environmental impacts can disrupt the sensory environment of animals and affect important processes from mate choice to predator avoidance. Currently, these effects are best understood for auditory and chemosensory modalities, and recent reviews highlight their importance for conservation. We examined how anthropogenic changes to the visual environment (ambient light, transmission, and backgrounds) affect visual communication and camouflage and considered the implications of these effects for conservation. Human changes to the visual environment can increase predation risk by affecting camouflage effectiveness, lead to maladaptive patterns of mate choice, and disrupt mutualistic interactions between pollinators and plants. Implications for conservation are particularly evident for disrupted camouflage due to its tight links with survival. The conservation importance of impaired visual communication is less documented. The effects of anthropogenic changes on visual communication and camouflage may be severe when they affect critical processes such as pollination or species recognition. However, when impaired mate choice does not lead to hybridization, the conservation consequences are less clear. We suggest that the demographic effects of human impacts on visual communication and camouflage will be particularly strong when human‐induced modifications to the visual environment are evolutionarily novel (i.e., very different from natural variation); affected species and populations have low levels of intraspecific (genotypic and phenotypic) variation and behavioral, sensory, or physiological plasticity; and the processes affected are directly related to survival (camouflage), species recognition, or number of offspring produced, rather than offspring quality or attractiveness. Our findings suggest that anthropogenic effects on the visual environment may be of similar importance relative to conservation as anthropogenic effects on other sensory modalities.  相似文献   
82.
Conservation programs often manage populations indirectly through the landscapes in which they live. Empirically, linking reproductive success with landscape structure and anthropogenic change is a first step in understanding and managing the spatial mechanisms that affect reproduction, but this link is not sufficiently informed by data. Hierarchical multistate occupancy models can forge these links by estimating spatial patterns of reproductive success across landscapes. To illustrate, we surveyed the occurrence of grizzly bears (Ursus arctos) in the Canadian Rocky Mountains Alberta, Canada. We deployed camera traps for 6 weeks at 54 surveys sites in different types of land cover. We used hierarchical multistate occupancy models to estimate probability of detection, grizzly bear occupancy, and probability of reproductive success at each site. Grizzly bear occupancy varied among cover types and was greater in herbaceous alpine ecotones than in low‐elevation wetlands or mid‐elevation conifer forests. The conditional probability of reproductive success given grizzly bear occupancy was 30% (SE = 0.14). Grizzly bears with cubs had a higher probability of detection than grizzly bears without cubs, but sites were correctly classified as being occupied by breeding females 49% of the time based on raw data and thus would have been underestimated by half. Repeated surveys and multistate modeling reduced the probability of misclassifying sites occupied by breeders as unoccupied to <2%. The probability of breeding grizzly bear occupancy varied across the landscape. Those patches with highest probabilities of breeding occupancy—herbaceous alpine ecotones—were small and highly dispersed and are projected to shrink as treelines advance due to climate warming. Understanding spatial correlates in breeding distribution is a key requirement for species conservation in the face of climate change and can help identify priorities for landscape management and protection. Patrones Espaciales del Éxito Reproductivo de Osos Pardos, Derivados de Modelos Jerárquicos Multi‐Estado  相似文献   
83.
Objective: Drink-driving represents a critical issue on international organizations’ agendas as one of the key behavioral risk factors in road traffic safety, alongside speed and nonuse of motorcycle helmets, seat belts, and child restraints. Changing road user behaviors regarding these 5 factors is a critical component in reducing road traffic injuries and casualties. The objective of this study is the identification of drivers who are more likely to contribute to crashes in the UK while impaired by alcohol to design targeted drink drive compliance campaigns.

Method: To profile drivers with the factor “impaired by alcohol” assigned in collisions, an extensive data set is used, including all reported injury collisions between 2011 and 2015 in the UK (police records), merged with the Experian Mosaic Database. A multilevel mixed-effects logistic regression is conducted, utilizing the hierarchical nature of the data (drivers within Mosaic types).

Results: Using multilevel mixed-effects logistic regression analysis, the finding is that some driver profiles are more likely to contribute to crashes and are assigned the contributory factor “impaired by alcohol.” Drink-related crashes are more common in some circumstances or for some crash-involved driver groups than others. For instance, alcohol-related crashes are more likely to occur on single carriageways and among males and 25- to 35-year-olds. Drink-drive-related crashes are found to be strongly associated with dark lighting conditions and, more specifically, with late night hours (the interval between 3:00 a.m. and 4:00 a.m. accounts for a third of the drink-drive-related collisions). Using the Experian Mosaic Database which divides the UK population into 66 types based on demographic, lifestyle, and behavior characteristics, the finding is that, among crash-involved drivers, some Mosaic types are significantly more likely (e.g., pocket pensions, dependent greys, streetwise singles) and others are significantly less likely (e.g., crowded kaleidoscope, cultural comfort, penthouse chic) to contribute to a drink-related crash.

Conclusions: The outcome is a more nuanced understanding of drivers contributing to drink-related crashes in the UK. The study concludes by discussing the implications for governments and other interested bodies for better targeting and delivery of public education campaigns and interventions.  相似文献   

84.
A definitional component of organizational climate is the focus on employees' shared perceptions of the focal climate domain. To operationalize the notion of sharedness, researchers typically aggregate employees' domain‐specific climate perceptions to a higher level and justify this aggregation using quantitative indices of agreement. In the current paper, I argue that although accounting for sharedness among employees can provide some valuable insight, our overreliance on sharedness obscures some of the very organizational phenomena of interest. I discuss this issue by focusing on four costs of making unfounded assumptions regarding sharedness: (a) Aggregation assumes individual differences are a function of random error; (b) aggregation assumes that social situations are uniform across employees; (c) aggregation assumes that the unit of analysis is clear‐cut; and (d) aggregation assumes the group mean is meaningful. I argue that researchers carefully need to weigh the costs of violating these assumptions against the expected benefits of aggregating employees' climate perceptions, recognizing that sometimes employees' perceptions (i.e., psychological climate) might provide greater insight into phenomena of interest. Although I discuss these costs within the context of organizational climate research, these arguments apply to other research areas where individual perceptions are aggregated (e.g., research on leadership and teams).  相似文献   
85.
Conservation and development practitioners increasingly promote community forestry as a way to conserve ecosystem services, consolidate resource rights, and reduce poverty. However, outcomes of community forestry have been mixed; many initiatives failed to achieve intended objectives. There is a rich literature on institutional arrangements of community forestry, but there has been little effort to examine the role of socioeconomic, market, and biophysical factors in shaping both land‐cover change dynamics and individual and collective livelihood outcomes. We systematically reviewed the peer‐reviewed literature on community forestry to examine and quantify existing knowledge gaps in the community‐forestry literature relative to these factors. In examining 697 cases of community forest management (CFM), extracted from 267 peer‐reviewed publications, we found 3 key trends that limit understanding of community forestry. First, we found substantial data gaps linking population dynamics, market forces, and biophysical characteristics to both environmental and livelihood outcomes. Second, most studies focused on environmental outcomes, and the majority of studies that assessed socioeconomic outcomes relied on qualitative data, making comparisons across cases difficult. Finally, there was a heavy bias toward studies on South Asian forests, indicating that the literature on community forestry may not be representative of decentralization policies and CFM globally.  相似文献   
86.
Agroforestry systems have substantial potential to conserve native biodiversity and provide ecosystem services. In particular, agroforestry systems have the potential to conserve native tree diversity and sequester carbon for climate change mitigation. However, little research has been conducted on the temporal stability of species diversity and aboveground carbon stocks in these systems or the relation between species diversity and aboveground carbon sequestration. We measured changes in shade‐tree diversity and shade‐tree carbon stocks in 14 plots of a 35‐ha coffee cooperative over 9 years and analyzed relations between species diversity and carbon sequestration. Carbon sequestration was positively correlated with initial species richness of shade trees. Species diversity of shade trees did not change significantly over the study period, but carbon stocks increased due to tree growth. Our results show a potential for carbon sequestration and long‐term biodiversity conservation in smallholder coffee agroforestry systems and illustrate the opportunity for synergies between biodiversity conservation and climate change mitigation. Interacciones entre el Secuestro de Carbono y la Diversidad de Árboles de Sombra en una Cooperativa de Café de Pequeños Agricultores en El Salvador  相似文献   
87.
Abstract: Avian conservation efforts must account for changes in vegetation composition and structure associated with climate change. We modeled vegetation change and the probability of occurrence of birds to project changes in winter bird distributions associated with climate change and fire management in the northern Chihuahuan Desert (southwestern U.S.A.). We simulated vegetation change in a process‐based model (Landscape and Fire Simulator) in which anticipated climate change was associated with doubling of current atmospheric carbon dioxide over the next 50 years. We estimated the relative probability of bird occurrence on the basis of statistical models derived from field observations of birds and data on vegetation type, topography, and roads. We selected 3 focal species, Scaled Quail (Callipepla squamata), Loggerhead Shrike (Lanius ludovicianus), and Rock Wren (Salpinctes obsoletus), that had a range of probabilities of occurrence for our study area. Our simulations projected increases in relative probability of bird occurrence in shrubland and decreases in grassland and Yucca spp. and ocotillo (Fouquieria splendens) vegetation. Generally, the relative probability of occurrence of all 3 species was highest in shrubland because leaf‐area index values were lower in shrubland. This high probability of occurrence likely is related to the species’ use of open vegetation for foraging. Fire suppression had little effect on projected vegetation composition because as climate changed there was less fuel and burned area. Our results show that if future water limits on plant type are considered, models that incorporate spatial data may suggest how and where different species of birds may respond to vegetation changes.  相似文献   
88.
为研究昌黎生态监控区夏季浮游植物群落结构特征及其与环境因子关系,采用2005~2013年夏季(8月)昌黎生态监控区海域浮游植物及环境因子的监测资料,基于Arc GIS 10.0和Canoco软件平台,运用典范对应分析方法,对浮游植物群落结构进行分析.结果表明,近9 a共鉴定出浮游植物3门23科39属105种,其中,硅藻门16科32属90种,占浮游植物总数的85.7%;甲藻门共6科6属14种,占总种类数的13.3%;金藻门1种.各年的优势种存在很大差异,按照优势度Y值的大小包括辐射圆筛藻(Coscinodiscus radiatus)、柔弱角毛藻(Coscinodiscus debilis)、笔尖根管藻(Rhizosolenia styliformis)、柏氏角管藻(Cerataulina bergoni)、威氏圆筛藻(Coscinodiscus wailesii)、海链藻(Thalassiosira sp.)、三角角藻(Ceratium tripos)、洛氏角毛藻(Coscinodiscus wailesii)、中肋骨条藻(Ceratium tripos)等.夏季细胞丰度年际变化较大,呈现逐渐降低的趋势.浮游植物的多样性指数H'值介于0.015~3.889,均匀度指数J值介于0.009~1,年际变化幅度较小;各站位间物种分布不均匀,优势种较少且优势度较大.对浮游植物群落与环境因子进行典范对应分析(CCA),结果表明影响夏季浮游植物群落结构变化的环境因子包括水温、营养盐(磷酸盐、硝酸氮、氨氮)、盐度等,且是各个环境因子相互作用的结果.  相似文献   
89.
误食土壤是污染物(如多溴联苯醚)人体(主要是儿童)暴露的重要途径,人体消化道内污染物吸收的生物可给性是针对此种暴露方式进行定量风险评估的有效途径之一.本研究采用体外消化实验模拟3种不同有机碳含量的天然土壤中典型多溴联苯醚(BDE-28、BDE-47、BDE-99和BDE-153)在胃和小肠消化液中的释放,验证部分消化释放的多溴联苯醚因消化残留固相表面的再吸附造成低估实际生物可给性,并通过不同水土比的拟合计算予以校正.结果表明,校正后的消化率普遍高于校正前;就不同土样而言,BDE-28、BDE-47、BDE-99和BDE-153在不同初始暴露浓度条件下平均提升比例范围分别为14.3%~42.3%、11.1%~32.1%、4.9%~12.3%和0.0%~7.7%.因此,未经校正的消化率会显著低估PBDEs消化道内的生物可给性,尤其是低溴代组分及PBDEs初始浓度较高或高TOC含量的土样.校正后BDE-28、BDE-47、BDE-99和BDE-153的消化率分别维持在21.9%~54.7%、18.8%~43.1%、13.4%~27.2%和9.3%~19.9%.此外,PBDEs的消化率与其辛醇-水分配系数的对数lg KOW呈显著负相关;而与土壤TOC含量及PBDEs初始暴露浓度的相关性并不显著,尤其是高溴代组分.  相似文献   
90.
中国城市热岛时空特征及其影响因子的分析   总被引:9,自引:6,他引:3  
曹畅  李旭辉  张弥  刘寿东  徐家平 《环境科学》2017,38(10):3987-3997
全球气候变暖背景下,城市热岛效应会加重城市地区的热胁迫,对人类健康和生存发展提出严峻挑战.近年来我国雾-霾污染情况严重,但雾-霾对城市热岛影响的认识仍较匮乏.本研究基于MODIS遥感卫星地表温度数据,明确了我国2003~2013年白天、夜间以及四季城市热岛的空间变化,并从生物物理学和生物化学角度定量分析其控制机制.结果表明,影响我国白天城市热岛强度的主要因素为人口、农田灌溉和植被活动.纬度、降水量、反照率以及气溶胶浓度是夜间城市热岛强度的主控因子.从对比城乡粗糙度、反照率等生物物理学属性的角度,揭示了乡村背景环境对城市热岛分析的重要影响.结果表明,雾-霾治理可以缓解我国夜间城市热岛现象和热胁迫,有利于缓解区域甚至全球气候变化.  相似文献   
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