褐菖鲉肝CYP 1A作为生物标志物监测厦门海域石油污染状况

以褐菖鲉为实验鱼类,以鱼肝微粒体CYP1A 生物标志物(EROD活性和CYP1A蛋白表达量)为指标,在厦门海域开展了两次野外监测实验,研究EROD活性和CYP1A蛋白表达量的变化,以及它们与海水和沉积物中石油类和重金属含量之间的相关性。结果表明,在现场属于一类海水的石油类浓度(0.0121-0.0242 mg/L)条件下,石油类就能够显著诱导褐菖鲉肝EROD活性和CYP1A蛋白表达量,鱼肝EROD活性和CYP1A蛋白表达量与海水中石油类含量均呈现极显著正相关,CYP1A蛋白表达量比EROD活性较为敏感和稳定。此外,在监测实验中,尚未发现这两种生物标志物受所监测海区的海水和沉积物重金属含量的影响。因此,利用褐菖鲉肝微粒体EROD活性和CYP1A蛋白表达量作为生物标志物监测海洋石油类及其PAHs污染是可行的,在海洋环境石油类污染监测及其生化效应评价中具有重要的应用价值。而且,把这两种生物标志物结合起来加以研究并推广应用将更有意义。     

景观生态学在荒漠化监测与评价中应用的初步研究——以青海沙珠玉地区为例

以青海沙珠玉地区为例对景观生态学在荒漠化监测与评价中的应用进行了初步研究,并主要分析了多样性、优势度和均匀度以及马尔科夫转移矩阵模型等指标和方法在荒漠化监测与评价中应用的景观生态学意义。     

Six years of wild bee monitoring shows changes in biodiversity within and across years and declines in abundance

Wild bees form diverse communities that pollinate plants in both native and agricultural ecosystems making them both ecologically and economically important. The growing evidence of bee declines has sparked increased interest in monitoring bee community and population dynamics using standardized methods. Here, we studied the dynamics of bee biodiversity within and across years by monitoring wild bees adjacent to four apple orchard locations in Southern Pennsylvania, USA. We collected bees using passive Blue Vane traps continuously from April to October for 6 years (2014–2019) amassing over 26,000 bees representing 144 species. We quantified total abundance, richness, diversity, composition, and phylogenetic structure. There were large seasonal changes in all measures of biodiversity with month explaining an average of 72% of the variation in our models. Changes over time were less dramatic with years explaining an average of 44% of the variation in biodiversity metrics. We found declines in all measures of biodiversity especially in the last 3 years, though additional years of sampling are needed to say if changes over time are part of a larger trend. Analyses of population dynamics over time for the 40 most abundant species indicate that about one third of species showed at least some evidence for declines in abundance. Bee family explained variation in species‐level seasonal patterns but we found no consistent family‐level patterns in declines, though bumble bees and sweat bees were groups that declined the most. Overall, our results show that season‐wide standardized sampling across multiple years can reveal nuanced patterns in bee biodiversity, phenological patterns of bees, and population trends over time of many co‐occurring species. These datasets could be used to quantify the relative effects that different aspects of environmental change have on bee communities and to help identify species of conservation concern.     

生物多样性监测指标体系构建研究进展

生物多样性监测是为确定与预期标准相一致或相背离的程度,而对生物多样性进行定期或不定期的监视,目前已成为生物多样性研究和保护的热点问题。生物多样性监测指标则是一些简化的生物或环境特征参数,说明生物多样性现状和变化趋势,以及人类活动压力对生物多样性的影响,以促进科学界、政府和公众间的沟通,提高生物多样性管理水平。近10年来,国际组织、政府机构和各国学者对生物多样性指标体系的构建进行了大量的探索工作,取得了很多进展,其中有些指标已经应用于实际监测项目。本文综述了生物多样性监测指标筛选的一般标准和指标体系构建的主要理论,梳理目前已提出或应用的主要生物多样性监测指标,以期为我国构建国家或区域尺度生物多样性监测指标体系提供参考。在此基础上分析提出：生物多样性概念的泛化、指标含义模糊以及知识和数据的缺乏是构建生物多样性监测指标的主要困难。我国未来的生物多样性监测指标体系构建需要关注以下两个方面：（1）紧密联系实际,构建适应性的监测指标体系,加强对典型生态系统区域的监测;（2）发展经济社会发展方面的指标,分析生物多样性变化的驱动力,为生物多样性保护和区域可持续发展提供科学依据。     

生物土壤结皮的分布影响因子及其监测

生物土壤结皮在荒漠化地区广泛分布。本文详细论述了生物土壤结皮的分布规律及其影响因素,如海拔高度、土壤、维管植物群落水分条件和干扰,以及生物土壤结皮在生态系统和景观变化监测和评价中的作用等。同时对中国西北地区生物土壤结皮的生态学研究和开发应用提供了研究的重点和方向。     

Solar radiation and functional traits explain the decline of forest primary productivity along a tropical elevation gradient

One of the major challenges in ecology is to understand how ecosystems respond to changes in environmental conditions, and how taxonomic and functional diversity mediate these changes. In this study, we use a trait‐spectra and individual‐based model, to analyse variation in forest primary productivity along a 3.3 km elevation gradient in the Amazon‐Andes. The model accurately predicted the magnitude and trends in forest productivity with elevation, with solar radiation and plant functional traits (leaf dry mass per area, leaf nitrogen and phosphorus concentration, and wood density) collectively accounting for productivity variation. Remarkably, explicit representation of temperature variation with elevation was not required to achieve accurate predictions of forest productivity, as trait variation driven by species turnover appears to capture the effect of temperature. Our semi‐mechanistic model suggests that spatial variation in traits can potentially be used to estimate spatial variation in productivity at the landscape scale.     

Extreme weather conditions correspond with localised vegetation death at Cradle Mountain,Tasmania

A chance observation of a drought‐related plant mortality event in early 2014 in a normally wet and cool alpine area was matched with local weather data providing a unique insight into this event. The observed plant death was largely indiscriminate in areas that were topographically predisposed to being susceptible to drought. The weather conditions surrounding this event included 5 weeks with very little rain, an extreme heatwave and subsequent brief periods where warm temperatures and dry air combined to produce highly evaporative conditions. Extreme weather conditions such as this are expected to occur with increasing frequency as a result of climate change. Observing and reporting on real‐world examples of how extreme weather events affect native vegetation is integral to improved climate change risk assessment and to inform future management actions.     

数字图像处理法确定林带疏透度随机误差研究

在分析以数字图像处理为测定法确定林带疏透度误差来源的基础上,对其中的随机误差进行研究,结果表明:林带整体疏透度的机误方差小于其冠部和干部的较大者;所研究的各类型林带各部位疏透度随机误差均遵从正态分布;林带整体疏透度随机误差的分布与树种和带内配置无关;北京杨、双阳快杨和其它类杂交杨的矩形或品字形配置林带各自冠部与干部疏透度机误方差之间无显著差异,而乡土杨林带干部的显著大于冠部的。本文还分别各类型林带的各部位确定了由林带疏透度测定值估计其总体实际值的随机误差限,并讨论了在测定林带疏透度过程中据该误差限计算样本量和划定测定范围的应用意义。最后总结提出:以增加测定同一林带不同样段像片数限定随机误差,通过模型计算订正疏透度测定值中的投影误差和影缩误差确定林带疏透度是建立完善的“数字图像处理法确定林带疏透度”新方法的可行途径。     

Stable phylloplane colonization by entomopathogenic bacterium Pseudomonas fluorescens KPM-018P and biological control of Phytophagous ladybird beetles Epilachna vigintioctopunctata (Coleoptera: Coccinellidae)

An entomopathogenic bacterium was isolated from tomato leaves and used as a microbial agent to control larvae of phytophagous ladybird beetles Epilachna vigintioctopunctata. The isolate was identified as Pseudomonas fluorescens KPM-018P on the basis of its bacteriological characteristics. KPM-018P produced extracellular chitinase to form a transparent zone around their colonies by hydrolyzing chitin in a minimal medium. Pale-yellow colonies turned red after a change of incubation temperature. These characteristics were availed as markers for tracking KPM-018P. The bacteria produced biosurfactants that enabled the bacteria to stably colonize the hydrophobic leaf surface; they were recovered without any considerable decrease even after a suspension of KPM-018P was sprayed onto leaves. KPM-018P, transformed with the gfp gene and observed with fluorescence microscopy, stably dwelled in the junctions of epidermal cells of bacteria-sprayed leaves. Ingestion of KPM-018P-sprayed leaves by the larvae caused prompt death of these insects to eventually suppress their pupation. This method is thus effective for decreasing the population of larvae and adult insect pests in the subsequent generation. The study provides an experimental basis for the biocontrol of herbivorous insect pests using a leaf-inhabiting, entomopathogenic strain of P. fluorescens.