Virtual Recording of Lichen Species: Integrating Terrestrial Laser Scanning and Gis Techniques

Rock outcrops along ridgelines, in block fields, and on cliff faces of Shenandoah National Park (SNP) provide unique habitats for numerous rare and endemic biotas. However, there are recent concerns about the long-term sustainability of these populations because of increased park usage (e.g., hiking, rock climbing) and environmental change (e.g., air chemistry, quality). Analysis of lichen-population dynamics provides insight into the rate at which these habitats are being degraded. As such, there is a need to develop a method to rapidly and accurately assess changes in lichen communities through space and over time. This study presents a new approach designed to record lichen species on rock outcrops. Terrestrial laser scanning (TLS) offers a new technique for recording individual lichen species (e.g., abundance, spatial distribution, extent, size, shape). An automated process is described to extract the lichen extent and shape in a standard GIS environment. These data are used to examine size classes, frequency, percent cover, and spatial pattern of a species of Phlyctis. The methodology and data extracted greatly improve rapid assessments and long-term monitoring of lichen populations.     

Induced biological soil crust controls on wind erodibility and dust (PM10) emissions

Inducing biological soil crust (biocrust) development is an appealing approach for dust mitigation in drylands due to the resistance biocrusts can provide against erosion. Using a portable device, we evaluated dust emissions from surfaces either inoculated with biocrust, amended with a plant-based soil stabilizer, or both at varying wind friction velocities. Four months after application, emissions from all treatments were either indistinguishable from or greater than controls, despite evidence of biocrust establishment. All treatments had greater surface roughness and showed more evidence of entrapment of windblown sediment than controls, factors which may have been partially responsible for elevated emissions. There was a synergistic effect of inoculation and stabilizer addition, resulting in a nearly two-fold reduction in estimated emissions compared to either treatment alone. Stepwise regression analysis indicated that variables associated with surface crust strength (aggregate stability, penetration resistance) were negatively associated with emissions and variables associated with sediment supply (sand content, loose sediment cover) were positively associated with emissions. With more time to develop, the soil-trapping activity and surface integrity of biocrust inoculum and soil stabilizer mixtures is expected to increase with the accumulation of surface biomass and enhancement of roughness through freeze–thaw cycles. © 2019 John Wiley & Sons, Ltd.     

Nutrients as a link between ionic concentration/composition and diatom distributions in saline lakes

Diatom profiles in closed-basin lake sediments are commonly used to reconstruct climate change based on the observed correlations between salinity (ionic concentration) and modern diatom assemblages. Diatom assemblages are strongly correlated not only with salinity but also anion composition, with certain taxa characteristic of carbonate systems and others sulfate-dominated waters. Although strong correlations exist, the actual mechanisms behind these correlations are unknown. Here we briefly review the influence of salinity and ionic composition on nutrient dynamics in saline lakes and suggest that these interactions may drive shifts in diatom species composition along gradients of ionic concentration/composition. We discuss the influence of salinity and anion composition on nutrient availability, as well as on nutrient requirements and uptake by diatoms.     

哈纳斯自然保护区地衣生态地理分布的研究

根据 1985年以来实地考察的基础上 ,对保护区自然地理条件和地衣生长发育的地理背景进行了分析 ,对地衣植被的生态地理分布规律进行了初步探讨。并对地衣植被进行了生态分类。     

印度洋深海热液区一株盐单胞菌Halomonas sp. YD-7的分离鉴定及研究

从印度洋深海热液区沉积物中筛选到一株耐盐菌,菌株形态呈杆状,长1.5～2.0 μm,宽0.5～0.7 μm,属革兰氏阴性菌,生长适温为4～55 ℃,最适为35 ℃;pH测试范围为4.0～10.5,最适为7.0;测试NaCl浓度为0～5.13 mol/L,最适为0.86 mol/L,该菌属于兼性厌氧菌.经16S rDNA鉴定该菌属于γ-变形菌纲(γ-Proteobacteria)盐单胞菌属(Halomonas),命名为Halomonas sp. YD-7.该菌与菌株Halomonas sp. ANT9086在进化位置上最为接近,同源性达98.1%,有可能是新种.对该菌株的生理生化特性进行了研究,发现该菌具有很强的适应能力,对温度、盐度和氧气的适应范围广.该菌株还具有很强的耐受和去除Mn2+的能力及一定的耐受和去除Cr6+的能力.表明该菌在污水处理与生物修复方面可能具有重要的应用价值.     

刺参对温度适应的生理生态学研究进展

综述了近年来刺参对温度适应的生理生态学研究进展,概述了温度对刺参生长、发育、繁殖的影响以及刺参对极端温度的生理生化适应机制,重点分析了温度波动对刺参生长的影响及其相关机制;夏眠过程中刺参行为和生理变化;温度历史对刺参温度耐受性的影响及其生理机制等,并对今后刺参温度生理生态学研究的热点进行了初步分析。     

Can ecological and evolutionary arguments solve the riddle of the missing marine insects?

We critically appraise the recent literature on the paucity of marine insects and conclude that this near‐absence does demand explanation; but this explanation is unlikely to be found in the suggested problems of depth for insect respiratory systems. We tentatively suggest some areas where further consideration may yield fruitful answers to this long‐standing evolutionary riddle.     

加纳热带自然保护区内反刍动物与非反刍动物对生境斑块利用的变化（英文）

食草动物处理和消耗食物受单位时间内饲料质量和数量有效性的不同影响。异速反应理论被认为是食草动物觅食栖息地选择的重要决定因素,并已经被广泛应用于不同体型的食草动物研究。但其在解释不同消化生理和体型的食草动物如何利用生境斑块方面尚不明确。本研究通过整合河马（河马科,大型非反刍动物）和牛（反刍动物）的觅食关系,揭示了不同消化生理和体型的食草动物对生境斑块的应用。整个雨季和旱季,通过在加纳的Bui国家公园布设的48块100 m×100 m的样方来分析物种密度降低与环境变量之间的显著关系。结果表明,雨季河马和牛更倾向于利用靠近河流的区域,但河马在旱季会选择远离河流的地区觅食。草地的高度也决定了这两个物种对草地的利用,河马选择使用更矮的草地。分析食物的质量可知,食物氮含量对反刍动物（牛）的斑块选择有显著影响。然而,酸性清洁纤维含量则与非反刍动物（河马）呈正相关。在Bui国家公园,草地高度和食物质量对斑块使用的高季节性影响主要是由河马和牛的消化生理和体型不同所决定。     

升温对丛生盔形珊瑚两种形态型代谢和共生藻光合生理的影响

文章研究了温度升高对一种造礁石珊瑚——丛生盔形珊瑚(Galaxea fascicularis)的两种形态型(H和S型)代谢和共生藻光合生理的影响。研究显示H型和S型对升温的生理响应差异明显:在虫黄藻水平上, H型丢失了大量的虫黄藻,减轻了共生体呼吸代谢的负荷; S型中虫黄藻数目尚可维持共生体呼吸代谢的需求,同时提高叶绿素b含量增强光的吸收。在宿主水平上,H型充分利用虫黄藻输送的营养物质,并通过异养摄食补偿能量消耗;S型宿主所储存的营养物质可以协助共生体适应热环境。结果表明,丛生盔形珊瑚两种形态型通过不同的能量利用方式适应环境的变化, H型倾向于维持共生体的代谢平衡,而S型倾向于提高共生藻的能量分配。