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1.
Although soil texture is an important predictor of upland forest composition in southern Michigan, the relationship in some areas is weak and other environmental factors may exert stronger control on species composition. One of these may be concealed subsoil lithology where coarse-textured glaciofluvial sediments are buried beneath finer-textured till. Samples of forest composition, soil, and subsoil characteristics from 48 less-disturbed woodlots in the south-central Lower Peninsula reveal that upland oaks and hickories are predominant where the till veneer is thin and sand and gravel are relatively near the surface. Where till is relatively thick and outwash is deeply buried, woodlot composition is sugar maple-beech. In each of these cases, soil texture is unrelated to stand composition. The likely effect of buried near-surface glaciofluvial sediments is moisture stress such that xeric species dominate these drier sites. The influence of subsoil on forest geography is a significant new finding with regard to southern Michigan and has possible application elsewhere in glaciated eastern North America. 相似文献
2.
Robert G. Darmody & Colin E. Thorn 《Geografiska Annaler: Series A, Physical Geography》1997,79(4):215-222
Chemical weathering and associated soil development trends on glacial forelands are commonly assumed to exhibit increases with time elapsed since glaciation. However, this gross trend is complicated by several other factors including elevation, aspect, and microtopography. This paper demonstrates that on the glacial foreland at Storbreen, Jotunheimen, Norway, chemical weathering and associated soil development trends show significant elevational influences. We sampled soils at shallow depths (0–1, 1–5, and 15–20 cm) at two sites on a moraine dated to 1750 at its elevational extremes of 1155 m (site L) and 1385 m (site H). The two moraine sites also differed developmentally from an adjacent 9000-year-old surface (site T) at an intermediate elevation, 1205 m. Analyses were conducted on the fine-earth fractions. Extractable elemental composition exhibited detectable differences between the same-age soils at different elevations with the lower site L tending to have measured parameters intermediate between the high site H and the older site T. Weathering, as indicated by mineralogy, was more pronounced at the 9000-year-old site T and least evident at the high elevation site H. In addition, elevation under the conditions of the field research may inhibit pedogenesis as indicated by the chemical data. Site H, for example, showed little variation with depth and had in general, less organic matter accumulation, smaller C:N ratio, greater pH, and lesser amounts of the measured extractable elements than the soil at site L. Site T generally had smaller pH and larger levels of the measured elements than the other sites. It was concluded that elevation has a significant control on weathering and pedogenesis that may mask the effects of age in this cold and wet environment. 相似文献
3.
《Urban geography》2013,34(1):80-88
Across Europe there is a lively policy and academic debate on what the essential conditions are for the development of new economic activities in city-regions. The focus is on knowledge-intensive and creative industries. Different theories (glocalization, clustering, embeddedness, path dependence, "hard" and "soft" location factors) identify the essential factors. In this article, we review debates and theories on these conditions and specifically focus on the different pathways city-regions follow. This results in a set of hypotheses, which are evaluated with empirical evidence from three city-regions: Amsterdam, Birmingham, and Budapest. In each of these city-regions factors can be identified that inhibit the growth of knowledge-intensive and creative industries as well as enable such development. Rather than moving toward a common type of city-region, it is likely that distinctive economic outcomes will be generated due to strengths and assets inherited from the past. 相似文献
4.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):187-188
One of the largest outlet glaciers from the ice cap Jostedalsbreen has been studied by various scientists during the 19th and 20th centuries, and a detailed programme of mass balance investigations has been carried out in recent years. The paper summarizes results from earlier studies, even from observations since the large advance about 1740, and particularly recent data. Detailed mass balance studies since 1962 have shown that the glacier is growing in volume (more than 6 m of water equivalent from 1962 to 1975) but this has not yet resulted in any advance of the ice front. The maximum observed ice velocity is 1.4 m/day on the tongue, where the ice thickness is about 200 m in a surveyed profile located below the ice falls. 相似文献
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6.
This article examines the effect of high foreclosure rates on postrecession lending. Our hypothesis is that high neighborhood foreclosure rates will have a significant and positive effect on the likelihood of mortgage loan denial. In a case study on Toledo, Ohio, we explore the role of foreclosure activity, race, and racial disparities in lending practices and how they differ across neighborhoods. Our results suggest that applicants in high-foreclosure neighborhoods have a greater likelihood of loan denial (ceteris paribus). We also find that minority applicants face a higher probability of loan denial in high-foreclosure minority neighborhoods. Overall, the results depict highly variable lending practices where race seems to make a difference albeit in a small subset of neighborhoods deeply affected by the foreclosure crisis. There is also some indication of a chilling effect on minority loan applicants in Toledo during the postrecession period. Key Words: foreclosure, logistic regression, mortgage lending, neighborhood contingency, race discrimination. 相似文献
7.
Upland swamps are a form of topogenous mire that occur on the plateau areas of eastern Australia. These systems are well recognized for their ecological value, but little is known about their internal hydrological function and how this relates to their geomorphic structure and evolution. In this study, the geomorphic, sedimentological, and hydrological properties of an intact upland swamp on the Budderoo Plateau NSW are investigated. The geomorphic structure of the swamp is simple, and the sedimentology comprises basal layers of coarse sands, overlain by several layers of organic accumulation up to 3.3?m in thickness. Each of these sedimentary units has different hydrological behaviors (rates of water throughflow and discharge) that drive the overall function of the swamp in response to rainfall of various magnitudes and duration. Four hydrological response types have been identified in the functioning of this swamp. These response types (RT) are characterized by different peaks and recession responses to rainfall. The form of the hydrograph produced is controlled by antecedent water table position and the amount, timing and duration of rainfall. Depending on antecedent moisture conditions, the swamp can operate either as a store for water or as a rapid conduit for water throughflow and overland flow. 相似文献
8.
This study examines the experiences of geography graduates who work in business, government, and nonprofit organizations. We analyzed 352 logs from eighty-two professionals detailing professional activities, challenges, and opportunities during one work week each month, over a period of six months. Our analysis explores interpersonal relationships and working conditions affecting participants’ progress toward work goals, workplace climate, and professional identity. Geographic information systems and technology accounted for more than half of the geographic skills respondents reported using on the job, and administrative and leadership factors were the most commonly cited types of transferable skills. Professional geographers value collaborative workplaces as well as opportunities to work independently with the confidence of their supervisors, and their sense of a professional identity is enhanced when they feel valued and are recognized for their work. Professional development activities are important because they reinforce geographers’ sense of positively contributing to their organizations, enhance interpersonal interactions, facilitate work on specific projects, and expand individuals’ knowledge and skills. Moreover, our findings suggest that nearly half of the reported workplace difficulties could potentially be reduced or eliminated as a result of more and better professional development. Nonetheless, many employers do not consistently provide opportunities for professional development to their employees. Based on our analysis, we contend that professional development is a beneficial investment for lifelong learning, from undergraduate and graduate education throughout the entire course of a professional career. 相似文献
9.
LARRY R. FORD 《Geographical review》1998,88(4):528-547
ABSTRACT. “Midtown” is an important but understudied component of the morphology and historical evolution of North American and, to a lesser extent, European cities, and landmark buildings have played a notable role in giving midtowns identity and prestige. Especially significant are the recent diffusion and expansion of the twinned “midtown-skyscraper” concept to the major cities of East and Southeast Asia. For a variety of reasons, it is likely that massive midtowns anchored by famous buildings will become most evident on the western fringe of the Pacific Rim. Western architectural, engineering, and planning firms are playing major roles in this diffusion and illustrate nicely the importance of exporting the service component of the global economy. Buildings and midtowns provide (reinforced) concrete examples of the impact of the new global economy on the landscapes of major cities. 相似文献
10.
ABSTRACTIn academic and policy discourse, the concept of urban resilience is proliferating. Social theorists, especially human geographers, have rightfully criticized that the underlying politics of resilience have been ignored and stress the importance of asking “resilience of what, to what, and for whom?” This paper calls for careful consideration of not just resilience for whom and what, but also where, when, and why. A three-phase process is introduced to enable these “five Ws” to be negotiated collectively and to engender critical reflection on the politics of urban resilience as plans, initiatives, and projects are conceived, discussed, and implemented. Deployed through the hypothetical case of green infrastructure in Los Angeles, the paper concludes by illustrating how resilience planning trade-offs and decisions affect outcomes over space and time, often with significant implications for equity. 相似文献
11.
Geography,Race, and Quantification 总被引：1，自引：0，他引：1
Perry L. Carter 《The Professional geographer》2013,65(4):465-480
This article reviews how race, quantification, and raced quantification have been used and written about in geography. Its two primary arguments are that race should be more central in the discipline and that a reluctance to address ontological and epistemological issues has left quantitative geography methodologically impoverished. These two issues merge in an examination of two cases where race is employed as a variable in quantitative models. The critique of these cases is not meant as a condemnation of quantitative geography but as an instructive example on which to construct a critical quantitative geography. The article ends by stressing the importance of quantification in geography and by presenting exemplars of race-critical quantification. 相似文献
12.
Forest city,Malaysia, and Chinese expansionism 总被引：2，自引：2，他引：0
Sarah Moser 《Urban geography》2018,39(6):935-943
Over the past decade, an acceleration of Chinese state and private investment in urban infrastructure and real estate has transformed many skylines around the world. In 2014, a private Chinese company in collaboration with Malaysia’s Sultan of Johor state started construction on Forest City, a private gated luxury mega-development for 700,000 people on four reclaimed islands in the narrow strait that separates Malaysia and Singapore. While the official material for Forest City claims it is for all nationalities, it is being marketed predominantly in China and to ethnic Chinese communities in Southeast Asia. This paper investigates the broader implications for Singapore, Malaysia, and the region and makes two key arguments. First, I suggest Forest City is more than a Chinese-financed real estate development, rather it constitutes a Chinese neocolonial outpost to which Malaysia has largely conceded sovereignty and advances China’s expansionist agenda. Second, Forest City challenges current geopolitical dynamics and threatens to undermine Malaysia’s relationships with neighbouring countries. 相似文献
13.
The scarcity of historical individual-level data makes understanding historic land use decisions and the influence of physiochemical gradients on these decisions difficult. Here, we present several measures of early property agricultural quality based on commonly available data, including elevation and soil type. These analyses demonstrate the influence of physiochemical gradients on initial land division patterns in the Gywnns Falls watershed (Baltimore, Maryland). Moreover, we examine the influence of the template created by early property decisions on continuing human-driven landscape dynamics. This influence is illustrated by 1900-era forest cover patterns, park locations, and modern transportation networks. 相似文献
14.
This study examines alpine soil development along a toposequence on Eagle Cap, Wallowa Mountains, northeast Oregon. Soils studied are from Wind Blown (WB) and Minimal Snow Cover (MSC) sites in the Ridge-Top Tundra geomorphic province. The soils are predominantly loamy sands, and exhibit minimal structural development. Soil pH ranges from 6.5 to 7.3 increasing with depth, and organic carbon ranges from 3.9% in the A horizon to 0.8% in the C horizon. The soils display significant input from Cascade volcanic ash infall and eolian influx from the weathered marble nearby. It is postulated that the ash content in the soils originates from Mazama Ash deposits. Though Eagle Cap soils have developed for the most part on granodiorite, the strong influence of the volcanic ash on pedogenesis leads to a preliminary classification of Andisols, most probably Typic and Lithic Haplocryands. [Key words: Alpine soils, Andisols, Wallowa Mountains.] 相似文献
15.
The meteorological data of ablation season in 2005 were recorded by two automatic weather stations on Keqicar Glacier, in the southwest Tianshan Mountains of China. One is operated on the glacier near the equilibrium line with an altitude of 4,265 m (Site A) and another is operated on the glacier ablation area with an altitude of 3,700 m (Site B). These data were used to analyze the meteorological conditions and the surface energy balance (SEB) of Keqicar Glacier. Net radiation was directly measured, and turbulent heat fluxes were calculated using the bulk aerodynamic approach, including stability correction. The ablation value of 0.68 m w.e. derived from four ablation stakes is in close correspondence to the modeled value of 0.71 m w.e. During the observation period, net radiation accounts for 81.4% of the total energy with its value of 63.3 W/m2. The rest energy source is provided by the sensible heat flux with a value of 14.4 W/m2. Energy is consumed mainly by melting and evaporation, accounting for 69.5% and 29.7% of the total energy with their values of 54.0 and 23.0 W/m2, respectively. Radiative energy dominates energy exchanges at the glacier-atmosphere interface, governed by the variation in net shortwave radiation. Net short-wave radiation varies significantly due to the effects of cloudiness and the high albedo caused by solid precipitation. Wind speed influences the turbulent heat fluxes distinctively and sensible heat flux and latent heat flux are much larger in July with high wind speed. 相似文献
16.
ALAN MORRIS 《Polar research》1989,7(1):79-82
The 'Scotiadalen Fault'appears on many maps but has not been identified as a single fault in the field. In addition, the sense of motion on the fault has been an open question. Here I show that this structure is a zone of distributed dextral strike-slip that is probably the result of Tertiary plate motion as the North Atlantic opened. As such it is one of the very few fault zones documented to show direct evidence of dextral, presumably Tertiary, strike-slip. 相似文献
17.
Two spatially separated sets of beach ridges were studied in Baja California. Each set contains several well-preserved beach ridges and each is adjacent to an arroyo mouth. Modern beach ridges mark coastal location whereas abandoned paleobeach ridges record coastal change. Paleobeach ridges were dated by absolute and relative techniques for rate-change, chronology, and longshore correlation purposes. With time, shape becomes more planar, foreslope angle is reduced, and there is a progressive tendency for constituent shingle to disintegrate and develop both rinds and surficial roughness. One paleobeach ridge on the lowest emergent terrace was assigned a 1,150 ± 230 yr. B.P. radiocarbon date whereas another beach ridge 18 km farther north has a partially overlapping date. Older but undated beach ridges also exist on the lowest emergent terrace as well as on the highest persistent terrace. Those beach ridges on the highest persistent terrace are highly weathered and Pleistocene in age. All beach ridges have paleogeographic implications and suggest that shoreline orientation has been generally stable although its position has shifted laterally by up to 720m westward in the last 1,150 ± 230 years. 相似文献
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19.
Women,Politics, Elections,and Citizenship 总被引：1，自引：1，他引：0
《The Journal of geography》2012,111(1):1-10
Abstract Significantly more women than men are registered voters in the United States, and a higher proportion of women voters actually cast ballots on election day. Yet the 106th Congress (1999-2001) includes only 56 women members, 12% of the total membership of the House and Senate. Likewise, women hold only 22% of the total seats in state legislatures. The purpose of this article is to examine this paradox. It first examines the history of the women's movement in the United States. It then turns to an evaluation of women's progress in gaining elected office. Finally it considers three primary obstacles to women gaining equitable representation: solidarity among women, political culture, and the single-member district system now employed in the United States. 相似文献
20.
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