青藏公路铁路沿线生态系统特征及道路修建对其影响   总被引：36，自引：2，他引：36  

陈辉  李双成  郑度 《山地学报》2003,21(5):559-567

根据2001—08和2002—08月野外调查数据及2001年1：100万中国植被图、1996年1：400万青藏高原植被区划图和2000年青藏铁路沿线自然保护区分布及功能区界调整图，以青藏公路铁路沿线植被生态系统为研究对象，运用ARCVIEW和ARC／INFO软件研究青藏公路铁路建设对沿线生态系统结构的影响，结论如下：①青藏公路铁路南北跨越9个纬度，东西跨越12个经度，共穿越青东祁连山地草原地带、柴达木山地荒漠地带、青南高寒草甸草原地带、羌塘高寒草原地带、果洛那曲高寒灌丛草甸地带和藏南山地灌丛草原地带6个自然区，对植被类型的统计结果显示了地带性。②青藏公路铁路的建设对生态系统产生直接的切割，使景观更加破碎。③青藏公路铁路的建设直接破坏沿线植被生态系统(主要为50m缓冲区内)，年损失总净初级生产量为30504．62t，损失总生物量432919．25～1436104．3t／a。损失总净初级生产量占1km缓冲区年净初级生产量535005．07～535740．11t／a的百分比为5．70％，占10km缓冲区年净初级生产量3408950．45～3810480．92t／a的0．80～0．89％；损失生物量占1km缓冲区生物总量7502971．85～25488342．71t／a的5．70％，占10km缓冲区总生物量43615065．35～164150665．37t／a的0．80％～0．89％。  相似文献   

Sediment Phosphorus Chemistry and Microbial Biomass along a Lowland New Zealand Stream   总被引：1，自引：0，他引：1  

R. W. McDowell 《Aquatic Geochemistry》2003,9(1):19-40

An evaluation of the distribution of P concentrations in streamflow, P fractions andthe microbial biomass P pool was made of bed and bank sediments along a lowlandstream in New Zealand. Agricultural intensification increased downstream. However,most P fractions decreased downstream (total P decreased from c. 400 to 250 mg kg^-1) in bed sediments, while P in streamflow remained relatively constant (generally < 0.005 mg l^-1) and sediment microbial P increased from 2 to 8 mg kg^-1. An investigation of P release from dried and rewetted sediments showed that solution P (CaCl2-P) increased, on average > 300%, and proportional to the size of the microbial biomass P pool before drying, except in sediments with much organic carbon (OC). When supplied with a P source (1 mg l^-1) and then simultaneously with a C source (glucose, 100 mg l^-1), all sediment behaved similarly and biotic sorption accounted for, on average, 27 and 34% of the total sediment uptake, respectively (maximum of 58%). The quantity of P taken up was related to the initial size of the microbial biomass P pool, and the availability of P as influenced by organic P complexes and OC. The sediment microbial biomass represents a transient, but small store of P could be useful to indicate bioavailable P inputs.  相似文献   

中国北方两种现代草地动物牙齿珐琅质δ~(13)C值与植被类型的关系初探     

李玉梅  刘东生  韩家懋  洪业汤  朱咏煊  董丽敏  彭建华 《矿物岩石地球化学通报》2003,(2)

在简单了解研究区的植被、气候状况的基础上 ,分析了内蒙古锡林郭勒和青海海北两种典型草地食草动物牙齿的δ1 3C值 ,测定了采样点表土有机质的δ1 3C值。锡林郭勒的表土有机质碳同位素组成略分散 ,且与植被和微环境密切相关。海北的表层土壤有机质碳同位素组成比较集中。两地的碳同位素组成都偏轻 ,是植被中C4植物含量少的反映。两地放牧动物的珐琅质δ1 3C值分别比当地植物偏重 12 .9‰和 13.5‰ ,或 14 .1‰和 14 .7‰。火灾等高温过程对动物牙齿的碳同位素组成可能没有显著影响  相似文献   

Small-scale vegetation dynamics in semi-arid steppe in Inner Mongolia     

Wei Zhang  Christina Skarpe 《Journal of Arid Environments》1996,34(4):421-439

Small-scale vegetation dynamics were followed for ecotones and in uniform stands inArtemisia-dominated steppe vegetation under grazing and when recovering from heavy grazing. Species composition was followed annually for 5 years in 1 m²and 0·25 m²plots for (1) presence–absence; (2) density; and (3) biomass.More rapid vegetation dynamics, in terms of change of type of vegetation and distance moved in DCA species space between sampling occasions, were observed in smaller plots and in early seral stages, where species were few and alpha diversity low. Only the plots recently protected from grazing showed a directional vegetation change; those protected for more than 3 years and those under continued grazing showed, at this scale, non-directional dynamics.  相似文献   

Life cycle of Agapetus fuscipes (Trichoptera, Glossosomatidae) in a first-order upland stream in central Germany     

Georg Becker   《Limnologica》2005,35(1-2):52-60

The number of immature stages and the seasonal patterns of development are basic life history features of a stream dwelling species and knowledge about these important components are essential for understanding its adaptations to its dynamic environment. The life cycle of Agapetus fuscipes (Trichoptera, Glossosomatidae), one of the dominant scrapers in the upper and middle reaches of the Breitenbach, a first-order upland stream in central Germany, was analysed. The pronotum length and the relationship between pronotum length, larval biomass and case length showed seven distinct larval instars, contrary to earlier findings from the Breitenbach. In addition to a few trichopteran species from other functional feeding groups, A. fuscipes is the only scraping caddis fly reported to have more than five larval instars. The moult increments of pronotum length and larval biomass were distinctly lower than in glossosomatid species with five larval instars. A. fuscipes is clearly univoltine in the Breitenbach. First-instar larvae were found from July to the beginning of December, and second-instar larvae from July to January. At the beginning of December the population consisted of the instars I to V, and development did not cease during winter. The sixth-instar larvae occurred mostly in January, and the seventh-instar larvae were never present before January. The prepupae and pupae occurred in April. The last pupae were found at the beginning of September, although most of the emergence took place in June and July. At least five different immature stages with different ecological demands were present at any time throughout the year. The ecological advantage having two additional larval instars compared to other glossosomatid species may be to compensate for the high rate of mouthpart wear that occurs while the larvae feed on the rough Bunter Sandstone substratum. A further advantage may be to spread the risk of high mortality under unfavourable environmental conditions.  相似文献   

植被生物量高光谱遥感监测研究进展   总被引：2，自引：0，他引：2  

姚阔  郭旭东  南颖  李坤  江淑芳  孙婷婷 《测绘科学》2016,(8):48-53

植被生物量的评估对于研究全球碳循环具有重大意义,而高光谱遥感技术为精确反演地表属性提供了重要的数据支持。针对如何更好地应用高光谱遥感技术进行植被生物量精确反演的问题,该文详细阐述了国内外应用高光谱技术估测植被生物量的研究进展。对反演植被生物量所涉及的数据源、反演模型的构建方法及其模型特点、反演模型应用对象等内容进行了综合评述,并通过分析认为,高光谱遥感技术较传统的多光谱遥感技术在生物量反演精度上有了显著的提高。同时,对建模方法、多源遥感数据融合以及模型通用性等方面的研究进行了展望,以达到在大尺度范围内对植被生物量进行准确反演的目的。  相似文献   

Application of topo-edaphic factors and remotely sensed vegetation indices to enhance biomass estimation in a heterogeneous landscape in the Eastern Arc Mountains of Tanzania     

Mercy Ojoyi  Onisimo Mutanga  John Odindi  Elfatih M. Abdel-Rahman 《国际地球制图》2016,31(1):1-21

Estimating tropical biomass is critical for establishment of conservation inventories and landscape monitoring. However, monitoring biomass in a complex and dynamic environment using traditional methods is challenging. Recently, biomass estimates based on remotely sensed data and ecological variables have shown great potential. The present study explored the utility of remotely sensed data and topo-edaphic factors to improve biomass estimation in the Eastern Arc Mountains of Tanzania. Twenty-nine vegetation indices were calculated from RapidEye data, while topo-edaphic factors were taken from field measurements. Results showed that using topo-edaphic variables or vegetation indices, biomass could be predicted with an R² of 0.4. A combination of topo-edaphic variables and vegetation indices improved the prediction accuracy to an R² of 0.6. Results further showed a decrease in biomass estimates from 1162 ton ha^?1 in 1980 to 285.38 ton ha^?1 in 2012. This study demonstrates the value of combining remotely sensed data with topo-edaphic variables in biomass estimation.  相似文献   

Satellite-measured atmospheric aerosol content in Korea: anthropogenic signals from decadal records     

Sunyurp Park 《地理信息系统科学与遥感》2016,53(5):634-650

Spatiotemporal characteristics and anthropogenic signals of aerosol optical thickness (AOT) distributions over Korea are investigated in this study using AOT time-series data from the Moderate Resolution Imaging Spectroradiometer (MODIS). AOT observations, a quantitative measure of the atmospheric quality, had significant geographical variations during the study period (2000–2010). Comparing metro cities or counties with similar populations, western regions showed higher AOT values than eastern regions. Particular matter with a diameter < 10 µm (PM₁₀), including aeolian dust or yellow dust, is the primary component of atmospheric aerosols, and their transport into the region has shown a strong seasonal pattern with its peak from March to April and lows from July to September. These seasonal dust patterns, however, did not correspond well to temporal AOT records, which typically reached the maximum level in June nationwide. Rather, widespread regional fire events and humidity showed significant correlations with AOT time-series. This correlation rapidly increased as the range of fire occurrence was extended to the west as far as 115°E. The relative humidity also had a significant correlation with AOT during the month of June. In addition to urban emission of anthropogenic aerosols, regional biomass burning and secondary growth of hygroscopic aerosols are considered important contributors to the degradation of the atmospheric environment during the non-Asian Dust season over the Korean Peninsula.  相似文献   

基于SPOT6遥感影像的滩涂湿地入侵种互花米草植株高度的反演研究   总被引：1，自引：0，他引：1  

周在明  杨燕明  陈本清 《海洋学报》2016,38(6):1-7

本文以SPOT6 高空间分辨率遥感影像为数据源,通过植被覆盖度和地上生物量两个参数进行滩涂湿地入侵种互花米草植株高度的估算研究。结果表明,三沙湾滩涂湿地互花米草植株高度平均值为2.04 m,以1~2 m和2~3 m植株为主要分布高度,分布面积分别为6.83 km2和10.31 km2,占研究区互花米草总面积的33.83%和51.06%,小于1 m和大于3 m的互花米草仅占9.26%和5.84%。估算值与真实值之间的均方根误差为0.204,绝对误差为0.04~0.37 m。该方法是对高空间分辨率光学影像应用研究的重要尝试,其反演方法具有较好的可行性,可较为准确的获取滩涂湿地植株高度信息。  相似文献   

不同培养条件对三角褐指藻生长及其生物活性成分积累的影响   总被引：1，自引：0，他引：1  

张文源  高保燕  李爱芬  张成武 《海洋科学》2016,40(5):57-65

以三角褐指藻(Phaeodactylum tricornutum)为研究材料,比较了Na NO3、NH4HCO3和CO(NH2)2为氮源的两种培养基(m L1和ASW培养基)对其生长和生物活性成分(岩藻黄素、金藻昆布糖和二十碳五烯酸(C20:5,EPA))时相积累的影响,同时分析了脂肪酸组成和总脂含量的变化。结果表明:以m L1培养基培养时,三角褐指藻的生物质质量浓度明显高于ASW培养基培养时的生物质质量质量浓度,尿素优于其他两种氮源,最大生物质质量质量浓度为3.7 g/L。不同培养条件下岩藻黄素含量的时相变化规律一致,均随着培养时间的延长呈现先增加后减少的趋势,其最高积累量分别为:13.27 mg/g(Na NO3)、13.23 mg/g(CO(NH2)2)和13.89 mg/g(NH4HCO3)(m L1);13.2 mg/g(Na NO3)、14.92 mg/g(CO(NH2)2)和13.6 mg/g(NH4HCO3)(ASW),由此可知氮源对岩藻黄素积累量影响不大。金藻昆布糖含量随着培养时间延长逐渐增加,其最大积累量分别为9.82 mg/g(NH4HCO3)(m L1)和8.59 mg/g(Na NO3)(ASW)。不同培养条件下其总脂含量变化不显著,均在培养末期达到最大值,分别为24.18%(NH4HCO3)(m L1)和23.79%(Na NO3)(ASW);其主要脂肪酸组成为:豆蔻酸(C14:0)、棕榈酸(C16:0)、棕榈油酸(C16:1)、硬脂酸(C18:0)、油酸(C18:1)、亚油酸(C18:2)、花生一烯酸(C20:1)、木焦油酸(C24:0)和EPA,其中,EPA含量随着培养时间延长逐渐下降,尿素最有利于EPA的积累。  相似文献