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1.
沼泽甲烷排放及其主要影响因素 总被引：20，自引：6，他引：20
综合评述了不同类型沼泽产生、氧化和排放甲烷能力的差异及其主要影响因素。沼泽水位的变化引起沼生植物种群更替，从而形成不同类型的沼泽及其土壤剖面形态特征，进而导致沼泽产生和排放甲烷能力的不同。腐泥沼泽产生和排放甲烷能力最强，泥炭沼泽次之，森林沼泽再次之，苔藓泥炭沼泽最弱。甲烷排放以夏季最多，春秋季次之，冬季最低。在影响沼泽排放甲烷能力中，水位的变化最为强烈，底物、植物种类及数量和温度次之，pH、外源氮和土壤性质也有一定的作用。 相似文献
2.
瑞典是泥炭沼泽广布，泥炭沼泽学研究历史悠久的国家。基于实地考察、交流与文献整理，分析了瑞典泥炭沼泽分布与成因、泥炭沼泽研究、利用及保护状况。早期的瑞典沼泽学者在泥炭沼泽分类、演化及沼泽植物地理学研究等方面处于国际领先地位，对学科的发展做出了重大贡献。目前，瑞典在泥炭沼泽的利用与保护方面也走在世界的前列，特别是泥炭沼泽合理利用与保护及恢复并举，值得我国湿地管理部门借鉴。 相似文献
3.
The northern and eastern sides of the Cuilcagh Mountain upland, in northwest Ireland, are mantled with over 50 km2 of blanket bog that has experienced an unusually high spatial and temporal frequency of peat mass movements. In all, 29 peaty-debris slides, nine bog slides, two peat slides and five more peat landslides of uncertain type have been recorded within this study area. More than 27 km2 of this peatland has been afforded several levels of statutory protection as well as international recognition of its geo-environmental importance. Field and laboratory investigations of the peat at several of the more recent failure sites showed it to be typical of Irish and Pennine (northern England) blanket bogs in most physical and hydrological respects. Field geomorphological evidence and modelling of stability thresholds indicate that the particular susceptibility of the Cuilcagh Mountain blanket bog to failure arises from two local factors: (i) the attainment of threshold maximum peat depths on the East Cuilcagh plateau, and (ii) the unconformable deposition of thin layers of glacial till (in places) and blanket peat over the pre-existing topographic surface formed from the major shale formations that underlie the northern slopes. With two exceptions, there is no conclusive evidence that human activities and management strategies for the area have had any significant influence on the occurrence of the peat landslides. The high frequency of large rainfall events since 1961 that did not trigger landslides suggests that failures are unlikely to become more frequent in response to climate change effects because they are controlled by slowly changing internal thresholds. 相似文献
4.
Recent decay of a single palsa in relation to weather conditions between 1996 and 2000 in Laivadalen, northern Sweden 总被引：2，自引：0，他引：2
Frieda Sjoukje Zuidhoff 《Geografiska Annaler: Series A, Physical Geography》2002,84(2):103-111
This study presents the decay of a small palsa complex between 1996 and 2000 in Sweden's southernmost major palsa bog. The outline of the palsa was mapped during three summers in 1996, 1999 and 2000 and an automatic weather station measured air temperature, precipitation, snow depth, wind speed and wind direction between 1997 and 2000. The decay of the palsa was enormous in the dome–shaped part of the palsa complex: the height decreased during the observation period from 2.3 m to 0.5 m. In 2000, the palsa dome had almost totally disappeared: only some peat blocks in a palsa pond were left. The decay of the palsa was complex with a number of degradational processes, of which the main processes were block erosion, thermokarst and wind erosion. Thermal melting has occurred along the edges of the palsa and possibly below the frozen core of the palsa since 1998/99. Wind erosion was observed during summer and the maximum estimated deflation was 80 cm. The decay of the palsa dome was especially large between 1999 and 2000, probably due to a high mean annual temperature, high summer precipitation and the warming influence of the large pond surrounding the palsa. The present climate in the palsa bog with a mean annual temperature of −0.8°C is not favourable for palsa development and maintenance, despite a strong wind regime which can provide suitable conditions for snowdrift. 相似文献
5.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(1):53-57
Sollid, J. L. &; Sørbel, L. 1974. Palsa bogs at Haugtjørnin, Dovrefjell, South Norway. Norsk geogr. Tidsskr. 28, 53–60. Palsa bogs are described from an area at Haugtjørnin, Dovrefjell (62° 21′N, 9° 45′ E). This locality is the southernmost reported occurrence of palsa bogs in Fennoscandia, see Fig. 1. The palsa bogs are in a degenerating stage. Morphology and erosional processes of different types of palsas are discussed. Melting of permafrost by water contact seems to be the most important erosional factor. Further studies are planned. 相似文献
6.
Characteristics of earth hummocks (pounus) with and without permafrost in Finnish Lapland 总被引：1，自引：0，他引：1
Finnish Lapland north of 68°30'N latitude is located in the zone of discontinuous permafrost. Two main types of permafrost have previously been found in northern Finland: palsas in the mires and frost in the bedrock on the barren fell summits. The aim of this study was (1) to investigate permafrost occurrence in the peaty earth hummocks (pounus) in several mires, and (2) model characteristics of pounus with and without permafrost.
This study showed that permafrost in Finnish Lapland occurs much more widely and commonly than was previously known. A total of 59% of the studied pounus were found to contain permafrost. Over 90% of the permafrost occurrence in the pounus was correctly classified in logistic regression modelling. The probability of permafrost in a pounu decreased with the height of vegetation, and increased with the pounu height and distance from the running stream. There were clear vegetation differences between pounus with and without permafrost. Unfrozen pounus are characterized by forest and mire species, whereas on the permanently frozen pounus the vegetation is patchier with species indicating drier conditions. Pounus provide an excellent object to study short–term and local variations in permafrost formation due to their small size. They react quickly to variation in temperature, snow depth and precipitation. We conclude that pounus can be classified as sporadic permafrost features in northernmost Europe under modern climatic conditions. 相似文献
This study showed that permafrost in Finnish Lapland occurs much more widely and commonly than was previously known. A total of 59% of the studied pounus were found to contain permafrost. Over 90% of the permafrost occurrence in the pounus was correctly classified in logistic regression modelling. The probability of permafrost in a pounu decreased with the height of vegetation, and increased with the pounu height and distance from the running stream. There were clear vegetation differences between pounus with and without permafrost. Unfrozen pounus are characterized by forest and mire species, whereas on the permanently frozen pounus the vegetation is patchier with species indicating drier conditions. Pounus provide an excellent object to study short–term and local variations in permafrost formation due to their small size. They react quickly to variation in temperature, snow depth and precipitation. We conclude that pounus can be classified as sporadic permafrost features in northernmost Europe under modern climatic conditions. 相似文献
7.
Ulla Kokfelt Nina Reuss Eric Struyf Mats Sonesson Mats Rundgren G?ran Skog Peter Rosén Dan Hammarlund 《Journal of Paleolimnology》2010,44(1):327-342
Permafrost in peatlands of subarctic Sweden is presently thawing at accelerated rates, which raises questions about the destiny
of stored carbon and nutrients and impacts on adjacent freshwater ecosystems. In this study we use peat and lake sediment
records from the Stordalen palsa mire in northern Sweden to address the late Holocene (5,000 cal BP-present) development of
the mire as well as related changes in carbon and nutrient cycling. Formation, sediment accumulation and biogeochemistry of
two studied lakes are suggested to be largely controlled by the development of the mire and its permafrost dynamics. Peat
inception took place at ca. 4,700 cal BP as a result of terrestrialisation. Onset of organic sedimentation in the adjacent
lakes occurred at ca. 3,400 and 2,650 cal BP in response to mire expansion and permafrost aggradation, respectively. Mire
erosion, possibly due to permafrost decay, led to re-deposition of peat into one of the lakes after ca. 2,100 cal BP, and
stimulated primary productivity in the other lake at ca. 1,900–1,800 cal BP. Carbonate precipitation appears to have been
suppressed when acidic poor fen and bog (palsa) communities dominated the catchment mire, and permafrost-induced changes in
hydrology may further have affected the inflow of alkaline water from the catchment. Elevated contents of biogenic silica
and diatom pigments in lake sediments during periods of poor fen and bog expansion further indicate that terrestrial vegetation
influenced the amount of nutrients entering the lake. Increased productivity in the lake likely caused bottom-water anoxia
in the downstream lake and led to recycling of sediment phosphorous, bringing the lake into a state of self-sustained eutrophication
during two centuries preceding the onset of twentieth century permafrost thaw. Our results give insight into nutrient and
permafrost dynamics in a subarctic wetland and imply that continued permafrost decay and related vegetation changes towards
minerotrophy may increase carbon and nutrient storage of mire deposits and reduce nutrient fluxes in runoff. Rapid permafrost
degradation may on the other hand lead to widespread mire erosion and to relatively short periods of significantly increased
nutrient loading in adjacent lakes. 相似文献
8.
青藏高原沼泽合理利用与生态环境保育 总被引：4，自引：0，他引：4
青藏高原有沼泽约491.3万hm2,是世界上最高的湿地。通过概要介绍高原沼泽湿地基本类型及其分布,重点阐述沼泽湿地利用、环境变化现状与存在的问题,为了保护高原生态环境,并持续利用湿地资源,提出了初步的看法和建议。 相似文献
9.
Numerical studies of earth surface processes in relation to their environment are one of the central topics in physical geography. However, collinearity between explanatory variables and spatial autocorrelation can hinder the detection of key environmental correlates underlying response–explanatory variables' relationships identified by traditional regression methods. Moreover, conclusions about the potential importance of environmental variables have generally made on analysis conducted only at one spatial scale (resolution). In this study, a variation partitioning method provided a framework to obtain new insights into the relative roles of different factors determining patterned ground activity at multiple spatial resolutions. The variation in the distribution of the sorted and non sorted patterned ground was decomposed into independent and joint effects of relief, soil and spatial variables (geographical location) based on a multi resolution system of 1 ha, 25 ha and 100 ha cells covering in total 100 km2 of a subarctic landscape in northern Finland.The independent effects of relief and soil variables captured the largest fraction of the variation in the non-sorted patterned ground distribution, while relief had a major contribution for sorted patterned ground activity. The independent effect of spatial autocorrelation on sorted patterned ground was higher than that on non-sorted patterned ground. However, a considerable amount of variation in the distribution of both patterned ground types was accounted for by the joint effects of explanatory variables and may thus be causally related to two or all three groups of variables. Our analyses produced often contradicting results at different resolutions. Consequently, this has substantial implications for the study of geomorphological systems, since the choice of resolution can have a major effect on the inferences of analyses. Our results draw attention to the roles of resolution and spatial autocorrelation in the study of geomorphological systems. 相似文献
10.
11.
湿地蓄水量动态SD仿真研究--以三江平原沼泽湿地为例 总被引：1，自引：0，他引：1
在沼泽湿地水循环系统分析基础上,根据系统动力学方法和原理,探讨湿地蓄水量动态仿真的方法、步骤和过程;以三江平原湿地生态实验站沼泽湿地为例,通过系统分析、函数建立、程序编写等过程建立了沼泽湿地蓄水量动态仿真模型,对模型反复检验和调试,直到获得较好的仿真效果;通过1997、1998、1999连续三年湿地水位变化实测与仿真结果的对比显示,仿真效果较好。 相似文献
12.
A study is made of the role of bogs in the formation of the annual runoff within the Middle Ob basin and its intra-annual distribution as well as making an assessment of the swampiness of the river catchments by using Landsat space images. It is shown that the overall swampiness of the catchments of almost all rivers under investigation(except for the Shegarka, Kargat, Chichka-Yul and Bol’shaya Yuksa rivers) as determined by analyzing the space images of the study territory exceeds, on the average, he previously obtained data by a factor of 1.5–2, while the influence of the bogs on the streamflow is different and depends on the occurrence of separate groups of bog microlandscapes, the structure of bog massifs, the character of location of the bogs on the catchment, and on the course and stage of their development. The area along the left bank of the Ob is dominated by raised bogs (49%) of the central-oligotrophic course of development and shows a regular alternation of definite groups of bog microlandscapes from the middle part to the margins of the bogs, and an almost total merging of elementary bog massifs to form major bog systems, such as the Vasyugan Swamp. As a result, the influence of the bogs on the streamflow is more clearly pronounced there. Along the right bank of the Ob, in conditions of the larger dissection of the terrain, the peripheral-oligotrophic course of development of the bog massifs is dominant, almost all bogs are in early stages of their development, with transition bogs predominating (49%) so that the bogs have a smaller influence on the streamflow. In conditions of an increase in swampiness of the catchments along the right bank of the Ob, it is found that the mean long-term layers of flow increase, whereas along the left bank the inverse situation is observed. The area along the right bank of the Ob shows an increase in evenness of the discharge within a year is observed with an increase in swampiness of the river catchments. The intra-annual runoff distribution of the rivers in the area along the left bank of the Ob is characterized by a larger irregularity, and by a decrease in the runoff at the low-water period with an increase in the area of the bogs. 相似文献
13.
Karl-Dag Vorren 《Norsk geografisk tidsskrift. Norwegian journal of geography》2017,71(2):114-121
The author studied the causal relationships between palsa formation, the maintenance of palsas, their final thawing, and climate. His main approach was to compare his observations with other researchers’ observations of recent palsa formation and degradation, and the use of relevant palaeoclimatic data. A more than 10 km2 large palsa mire complex in Sør-Varanger Municipality, northern Norway, was studied in terms of vegetation and stratigraphy 50 years ago, and then observed between 2005 and 2015, when the final palsa thawing occurred. The decisive climatic factor for the maintenance of existing palsas – annual mean temperatures below -1 °C, stated earlier by researchers – seemed to be valid also in the studied case. However, the results showed that new palsa formation may require a series of consecutive years with temperatures between -1 and -2 °C in annual mean temperatures. There is a possibility of detecting former palsas (i.e. since thawed) by stratigraphic investigations in cases of lateral erosion of palsas. Stratigraphic corings and field observations in the selected study area did not indicate earlier periods of palsa thawing prior to the modern one. The author concludes that the present thawing thus reflects a reversal of the final cooling stage of the present interstadial (Holocene). 相似文献
14.
选择长白山地区2种不同类型的泥炭沼泽,进行了典型剖面的大气铅沉降研究。植物残体和泥炭性质表明老白山泥炭地已经发育到贫营养阶段,而大桥泥炭地还处于富营养状态。两地泥炭记录的总铅含量和沉降速率与中国其他地区在同一个数量级上。老白山泥炭记录的大气铅在总铅中占主导地位,大气铅与富集因子呈明显的正相关（r=0.874,n=16,p<0.01）,且在16世纪中叶、18世纪初和20世纪出现峰值。大桥泥炭记录的铅可能存在再迁移和再沉降现象,但是相对较弱,因此,它也可以被用来重建当时的大气沉降。 相似文献
15.
16.
"泥炭气候成因说"的探讨 总被引：4，自引：2，他引：2
文章从沼泽有机质积累的本质和泥炭的定义出发,通过对地带性气侯与沼泽小气候、泥炭的现状分布与自然分布、“没有泥炭分布”地区与“不能形成泥炭”地区、地区差异与地带性分异规律等几对矛盾在泥炭形成与分布中的作用和地位的详细剖析,认为：各种地带性气候条件下都能因为地表积水而形成湿地小气候,不同地带内湿地小气候都具有湿润的特征;泥炭沼泽的形成与分布主要是与湿地小气候及积水厌氧环境有关,用与泥炭形成没有直接联系的地带性气候指标来研究泥炭形成与分布的规律性是不合逻辑的;地带性的水热条件主要对泥炭在不同地带的分布面积起到一定的控制作用;泥炭现状分布因为人类活动的影响已不是自然规律的表现,从不能反映泥炭形成与分布自然状况的泥炭现状分布来分析泥炭形成与分布的自然规律,显然也不能得出正确的结论;“没有泥炭分布”的地区并不是因为这里的水热条件组合不能形成泥炭,各自然地带内都可形成泥炭且所有地带内的泥炭特征都是相似的,没有必要将它们区别对待,这些事实说明“泥炭气候成因说”对泥炭形成与分布的规律性的解释是不合逻辑的,泥炭的分布不具有地带性的规律。 相似文献
17.
三江平原沼泽的生态分类 总被引：1，自引：1，他引：0
本文根据生态学原则,采用主成分、聚类制别分析相结合的方法,对三江平原沼泽进行生态分类。将该区沼泽划分为二个沼泽类、四个沼泽亚类和八个沼泽体。并给出了衡量沼泽类型之间差异的数量尺度和对未知类型归类的判别数学模型,并论证了沼泽生态分类应采用的重要指标。 相似文献
18.
若尔盖高原生态环境恶化与沼泽退化及其形成机制 总被引：70，自引：0，他引：70
根据１９９６－１９９８年野外考察与研究获得信息,结合前人研究的资料,论证了若尔盖高原沼泽区生态环境恶化,沼泽退化十分严重,其主要表现为：沼泽旱化,沼泽类型改变,沼泽逆向生态演替,沼泽区沙化,野生动物种类,种群数量减少,土壤质量下降,沼泽水质变劣,草场退化和鼠害猖獗,剖析了沼泽区生态环境恶化,沼泽退化与人类活动干扰,自然因素作用的关系,进而阐明了人类活动干扰是沼泽区生态环境恶化,沼泽退化主要原因。 相似文献
19.
Climatic and Anthropogenic Influences on Radial Growth of Scots Pine at Hanvedsmossen, a Raised Peat Bog, in South Central Sweden 总被引：1，自引：0，他引：1
Past studies of the climatic influence on tree growth at peat bogs in northern latitudes have shown weak correlation between annual tree-ring widths and climatic parameters during the growing season. At Hanvedsmossen, a raised peat bog in south central Sweden, tree-ring width chronologies from one drained and one undrained growth site, as well as one dry site outside the bog, were compared to meteorological records. Low temperatures, which means less evaporation, as well as high precipitation appear to be inhibiting pine growth at the undisturbed bog site as the trees are sensitive to changes in the local water table. Drainage causes an instant increase in annual tree growth for approximately 10 years. If draining is maintained, the response to climate of the pines resembles that of pines growing on mineral soils. The variance in annual tree-ring growth explained by temperature/precipitation or both was low for the entire lengths of all chronologies, but high for some analysed subperiods; the significant months changed with time. The reason for this seems to be that pines at Hanvedsmossen are growing in a region where precipitation and temperature are less limiting to tree growth than at higher and lower latitudes. 相似文献
20.
Salt rim synclines contain important hydrocarbon and coal resources in central Europe. The Schöningen salt rim syncline is filled with >300 m of Early to Middle Eocene unconsolidated clastics with interbedded lignitic coal seams that are mined at the surface. In this study, 357 lithologic logs are integrated with measured outcrop sections and paleo‐botanical data to interpret the depositional environments and sequence stratigraphic framework of the rim syncline fill. As salt withdrew, it generated an elongate mini‐basin that mimicked an incised valley. The sustained accommodation and slow broadening of the syncline affected the stratigraphic architecture and contributed to the preservation of coal units. The clastic units in the syncline filled in seven depositional stages: (1) tidally influenced fluvial estuarine channels; (2) mixed tide‐ and wave‐ dominated estuaries; (3) prograding wave dominate deltas; (4) transgressive shoreline deposits; (5) braided fluvial channels; (6) estuaries; and (7) prograding tide‐dominated channels. The succession defines four 3rd order sequences and several higher order sequences that are possibly related to Milankovitch cycles. The higher order sequences are dominantly characterized by stacked transgressive cycles of thick, lowstand coals overlain by estuarine sands. The nearly continuous warm and wet Eocene climate was conducive to continuous peat production with a climatic overprint recorded in the mire type: ombrotrophic mires developed in wetter times and rheotrophic mires developed in relatively drier conditions pointing to the presence of orbitally controlled seasonality. Both mire types were impacted by the interplay of subsidence and base‐level. The continuous dropping of the mires below base‐level via subsidence protected the mires against erosion and may account for the absence of coals outside of the rim synclines in the region. 相似文献