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Juanita Sundberg 《Geoforum》2005,36(1):17-28
This paper argues that critical geographies of Latin America begin with an analysis of how and why the bodies and geographies of geographers themselves matter. To focus on the geographer as a producer of knowledge is not to advocate the kind of navel gazing so abhorrent to many scholars. Rather, it is an effort to call attention to and critically assess how the geographer's embodied social position and geographic location inform the production of knowledge about and representations of Latin American people and nature. To illustrate how and why bodies and geographies matter, I draw from feminist and post-colonial theory and include examples from my own experiences and those of other researchers doing fieldwork in Latin American countries. I conclude by exploring the notion of situated knowledge as a tactic that writes bodies and geographies into academic texts. Ultimately, situating knowledge represents a political intervention and contribution to the broader goals of emancipatory politics shared by critical human geographers. 相似文献
3.
Thomas?R.?FisherEmail author Anne?B.?Gustafson Gregory?M.?Radcliffe Karen?L.?Sundberg J.?Court?Stevenson 《Estuaries and Coasts》2003,26(6):1450-1460
Photosynthetically available radiation (PAR; 400–700 nm, E m−2 d−1) is the fraction of the total solar energy (Mjoules m−2 d−1) that is used by organisms for photosynthesis and vision. We present a statistical summary of a 17-yr time series of PAR
data (1982–1998) collected near Chesapeake Bay as well as a second set of data on PAR and total solar energy gathered over
a shorter time span (1997–1998). The time series data (5,126 daily totals) varied between 1–67 E m−2 d−1 and were used to estimate the minimum and maximum values of PAR as a function of day of the year. In monthly frequency distributions
of the PAR data, three modes were observed corresponding to sunny, partly cloudy, and overcast days. The second set of PAR
and total solar energy data were used to examine the ratio of PAR to total solar energy, which was 2.04 E Mjoule−1 for PAR between 10 and 70 E m−2 d−1. On overcast days, the ratio increased to as high as 3 E Mjoule−1 as PAR increased in importance as a fraction of the total solar energy. These values were consistent with others in the literature,
and the relationships reported here can be used to predict the climatology of PAR and total solar energy within the Chesapeake
region. The PAR data were also combined with reported minimum values of PAR for net primary production in the surface mixed
layer of the water column of aquatic systems to estimate the combinations of mixed layer depth and diffuse attenuation coefficient
(number of optical depths) under which light limitation of phytoplankton primary production is expected to occur. 相似文献
4.
Cynthia H. Paquette Karen L. Sundberg Roelof M. J. Boumans Gail L. Chmura 《Estuaries and Coasts》2004,27(1):82-89
We examine the potential for diurnal variation in elevation of saltmarsh surfaces as a source of error in long-term experiments;
errors particularly critical in high precision studies that employ the surface elevation table (SET) as a means to monitor
elevations. The field study was carried out along the New Brunswick coast of the Bay of Fundy in high and low zones at three
marshes with different tidal ranges. We used a total of 16 benchmark pipes and controlled for daily variability in evapotranspiration
(ET), as well as timing of tidal flooding, two factors that affect soil water storage, and consequently soil volumes. In six
of nine trials we detected significant elevation change over periods as short as 5 d. Marsh-wide averages ranged from 1.2
to 3.0 mm, greater than the yearly increase in relative sea level in many regions. Wood Point marsh had the highest tidal
range, but lowest soil organic matter content, giving its soils the lowest compressibility and little sensitivity to ET during
two of three trials; the average change in elevation in Wood Point high marsh stations was 4.0 mm during the last trial. Greater
differences later in the growing season (while temperature changes were minor) at Wood Point and another site suggest that
plant transpiration drove changes in water storage at those sites. Significantly greater differences in elevation with lower
plant cover in the third marsh suggests that evaporation drove changes in water storage there. Surface elevation change due
to ET should be of greatest concern to SET users in temperate regions where there are large changes in plant biomass and variable
temperatures. Variation due to plant transpiration could be reduced if yearly monitoring is scheduled before the start of
the growing season. 相似文献
5.
Juanita Sundberg 《The Professional geographer》2003,55(2):180-190
Given the importance of fieldwork in Latin Americanist geography, it is intriguing to note the absence of a dialogue about the politics of fieldwork within the subdiscipline. Drawing from feminist theories about the production of knowledge, this article suggests that the silence about fieldwork is rooted in masculinist epistemologies that predominate in Latin Americanist geography. After analyzing the epistemological and pedagogical implications of masculinism, I argue for increased attention to the nexus of power and knowledge and in particular, to how the researcher's geographic location, social status, race, and gender fundamentally shape the questions asked, the data collected, and the interpretation of the data. Dialogue about these issues in our teaching and writing not only will better prepare students for fieldwork, but also has the potential to foster research that subverts rather than reproduces power inequalities. 相似文献
6.
Linderoth M Hansson T Liewenborg B Sundberg H Noaksson E Hanson M Zebühr Y Balk L 《Marine pollution bulletin》2006,53(8-9):437-450
By measuring a battery of basic physiological biomarkers and the concentration of SigmaDDT in adult female perch (Perca fluviatilis), an assumed aquatic pollution gradient was confirmed, with the city of Stockholm (Sweden) as a point source of anthropogenic substances. The investigation included an upstream gradient, westwards through Lake M?laren (46 km), and a downstream gradient, eastwards through the Stockholm archipelago (84 km). The results indicated a severe pollution situation in central Stockholm, with poor health status of the perch: retarded growth, increased frequency of sexually immature females, low gonadosomatic index, and disturbed visceral fat metabolism. SigmaDDT, measured as a pollution indicator, was 10-28 times higher than the background in perch from the Baltic Proper. Besides the main gradient other sources of pollution also influenced the response pattern of the measured biomarkers. In particular, there were strong indications of pollution coming from the Baltic Sea. 相似文献
7.
Climate Variability and Land-use Change in Danangou Watershed, China—Examples of Small-Scale Farmers' Adaptation 总被引:2,自引:0,他引:2
Johanna Hageback Jenny Sundberg Madelene Ostwald Deliang Chen Xie Yun Per Knutsson 《Climatic change》2005,72(1-2):189-212
With global concern on climate change impacts, developing countries are given special attention due their susceptibility.
In this paper, change and variability in climate, land use and farmers' perception, adaptation and response to change are
examined in Danangou watershed in the Chinese Loess Plateau. The first focus is to look at how climate data recorded at meteorological
stations recently have evolved, and how farmers perceived these changes. Further, we want to see how the farmers respond and
adapt to climate variability and what the resulting impact on land use is. Finally, other factors causing change in land use
are considered. Local precipitation and temperature instrumental data and interview data from farmers were used. The instrumental
data shows that the climate is getting warmer and drier, the latter despite large interannual variability. The trend is seen
on the local and regional level. Farmers' perception of climatic variability corresponds well with the data record. During
the last 20 years, the farmers have become less dependent on agriculture by adopting a more diversified livelihood. This adaptation
makes them less vulnerable to climate variability. It was found that government policies and reforms had a stronger influence
on land use than climate variability. Small-scale farmers should therefore be considered as adaptive to changing situations,
planned and non-consciously planned. 相似文献
8.
Rangia cuneata larvae were given the opportunity to settle on substrate types that differed in grain size, organic content, and bacterial abundance. Larvae settled in very fine sand (63–125 μm) and fine and medium sand (125–500 μm) more than in silt and clay (<63 μm) or on a hard substratum (empty polystyrene petri dishes). Proportionally more larvae settled onto untreated sediment from the adult habitat than onto the same sediment autoclaved, or treated with either H2O2 to remove organic material, or treated with antibiotics to reduce bacterial abundance. However, it appears that competent larvae do not delay settlement, even in the absence of “attractive” substrates. 相似文献
9.
Jennifer L. Stone‐Sundberg Yunbin Guan Ziyin Sun Troy Ardon 《Geostandards and Geoanalytical Research》2021,45(1):207-221
The attractive physical and chemical properties of corundum lend to this material’s importance in both its natural and synthetic forms. However, much of the quantitative work performed on this material is plagued by unknown inaccuracy as non‐matrix‐matched reference materials are used. To conduct accurate quantitative analysis using SIMS, matrix‐specific relative sensitivity factors (RSFs) were determined for eighteen trace elements in corundum using dose‐verified ion implants. The RSF values ranged from 2.56 × 1022 to 3.29 × 1024 cm‐1 with total combined uncertainty values ranging from 7 to 10%. The RSF values, which are related to ionisation potentials, showed trends consistent with expectations for an insulating oxide. The developed values were applied to calibrate reference materials for LA‐ICP‐MS and to study other natural and synthetic corundum samples. A measurement reference material calibrated for Mg, Si, Ti, V, Fe and Ga produced consistent results over ten sessions in 4 years with relative standard deviations per trace element of 5% or less, confirming the repeatability of our process. A key finding was that calibrating LA‐ICP‐MS with NIST SRM 610 and 612 glasses to analyse corundum resulted in under‐reporting trace elements Be, Ti, V, Fe, Co, Ni and Ga compared with using matrix‐matched reference materials. 相似文献
10.
Sundberg H Tjärnlund U Kerman G Blomberg M Ishaq R Grunder K Hammar T Broman D Balk L 《Marine pollution bulletin》2005,50(2):195-207
For reliable monitoring of environmental improvement, the PCB contaminated bay Orserumsviken on Sweden's Baltic coast was investigated prior to remediation. We examined PCB congener patterns and the relative toxic potential of PCBs in extracts of three matrices: bottom sediment, settling particulate matter and the dissolved phase (obtained from semi-permeable membrane devices). Congener patterns were similar in all matrices. Three fractions were isolated from the extracts: (1) aliphatic and monocyclic aromatic compounds (MAC-fraction), (2) dicyclic aromatic compounds (DAC-fraction), including PCBs, and (3) polycyclic aromatic compounds (PAC-fraction), including PAHs. Total extracts and fractions were injected into newly fertilised rainbow trout eggs. At larval stage, hepatic EROD activities were quantified. Though high, the PCB contamination could explain only an estimated 1-5% of the total EROD induction. The order of EROD induction potential was: total extract > PAC-fraction > DAC-fraction > MAC-fraction in all matrices, suggesting that in Orserumsviken PACs made a larger contribution to the EROD induction potential than PCBs and other DACs. 相似文献