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31.
The current study focuses on understanding key factors controlling geochemical export in eight diverse coastal watersheds at seasonal and annual time scales. Geochemical, atmospheric and hydrologic data across a range of hydro‐climatic regimes and varying land uses were investigated and relationships analysed. A hyperbolic dilution model was fitted for each watershed system to evaluate discharge–concentration relationships. Nitrate concentration effects were observed in watersheds exposed to high atmospheric deposition rates as well as agricultural watersheds, whereas urban watersheds showed nitrate dilution effects. Dilution patterns were observed for calcium, magnesium and sulfate for almost all watersheds. Seasonal loads for almost all constituents were noted to be mainly driven by hydrologic seasonality, but are also dependent on inputs (atmospheric deposition and land use sources). Understanding the primary controls on hydro‐chemical interactions is critical for developing and refining predictive water quality models, especially in coastal watersheds where sensitive downstream ecosystems act as receiving waters for upstream pollutant loads. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Lesley L. Rhodes Joann M. Burkholder Howard B. Glasgow Parke A. Rublee Coy Allen Janet E. Adamson 《新西兰海洋与淡水研究杂志》2013,47(3):621-630
Pfiesteria shumwayae Steidinger et Burkholder is now known to be present in New Zealand and occurs in estuaries around the country. The presence of Pfiesteria was initially determined by a polymerase chain reaction (PCR)‐based detection assay, using oligonucleotide primers targeted at ribosomal DNA extracted from estuarine water and sediments. Presence was confirmed by isolation from fresh sediments in the presence offish (Oreochromis mossambicus), followed by identification by scanning electron microscopy. The New Zealand isolates of P. shumwayae were ichthyotoxic in bioassays, but there is no historic evidence offish kills in New Zealand associated with the dinoflagellate. 相似文献
36.
Janet M. Bradford 《新西兰海洋与淡水研究杂志》2013,47(1):12-40
The genus Euaetideus Sars, 1925 is here merged with Aetideus Brady, 1883 (Copepoda : Calanoida : Aetideidae). Three new species of the genus Aetideus are described from the Pacific as well as the males of three other known species. A key is given to the known males and females in the genus Aetideus. The closely related genera Paivella and Snelliaetideus are compared with Aetideus. 相似文献
37.
Janet M. Bradford 《新西兰海洋与淡水研究杂志》2013,47(1):120-140
Three new species of calanoid copepods are described: two in Heterorhabdus and one in Disseta. The males of H. pustulifer and H. caribbeanensis are described and the identities of H. proximus, H. norvegicus and H. austrinus are clarified. H. spinifer is recorded for the second time. A key to the subgenus Heterorhabdus is provided. 相似文献
38.
Records of pelagic copepods off Kaikoura,New Zealand 总被引:1,自引:1,他引:0
Janet M. Bradford 《新西兰海洋与淡水研究杂志》2013,47(4):351-363
Additions to the pelagic copepod fauna of Kaikoura, New Zealand, include 20 species previously unrecorded and the males of 8 species for which females only had been recorded; further information concerning 2 other species is added. 相似文献
39.
Janet Franklin 《国际地球制图》2013,28(2):57-63
Vegetation types were discriminated using SPOT multispectral data on Miti'aro, a tropical oceanic island in the Cook Islands, Polynesia. Vegetation categories included undisturbed and disturbed forest on limestone, scrub, marsh, and other forest vegetation (including secondary upland forest and agroforestry). Most category pairs had high separability as measured by Jeffries‐Matusita distance and Euclidean distance for training site data. However, there was some class overlap as illustrated by unsuperaised clustering and assigning spectral clusters to vegetation classes using a reference map. Cloud cover was a problem encountered in optical imaging of this maritime tropical study area. 相似文献
40.
Birger Rasmussen Ian R. Fletcher Janet R. Muhling 《Contributions to Mineralogy and Petrology》2011,162(6):1259-1277
Xenotime is a widespread accessory mineral in lower greenschist to upper amphibolite facies metasedimentary rocks from the
Palaeoproterozoic Mount Barren Group, southwestern Australia. Xenotime is closely associated with detrital zircon, commonly
forming syntaxial outgrowths, in samples of sandstone, micaceous quartzite, slate, phyllite, garnet-bearing semi-pelites,
and in kyanite-, garnet-, and staurolite-bearing mica schists. In situ geochronology of xenotime from lower greenschist sandstones
has previously yielded multiple U–Pb ages with peaks at ~2.0, ~1.7, and ~1.65 Ga, interpreted to represent the age of detritus,
early diagenesis, and a later thermal event, respectively. New U–Pb dating of xenotime in slate yields a major population
at ~1.7 Ga with a minor population at ~1.2 Ga, reflecting diagenetic and metamorphic growth, respectively, whereas xenotime
in phyllite forms a minor age population at ~1.7 Ga and a main peak at ~1.2 Ga. Mid-greenschist facies semi-pelitic schists
(quartz-muscovite-garnet) contain xenotime that formed before 1.8 Ga and at 1.2 Ga, representing detrital and peak metamorphic
ages, respectively. Xenotime in samples of amphibolite facies schist (650°C and ~8 kbars) yields U–Pb ages of ~1.2 Ga, coinciding
with the time of peak metamorphism. A single analysis of a xenotime core from an amphibolite facies schist gave an age of
~1.8 Ga, consistent with the presence of detrital xenotime. Our results suggest that detrital xenotime may be preserved under
greenschist facies conditions, but is largely replaced during upper amphibolite facies conditions. Detrital xenotime is replaced
through dissolution–reprecipitation reactions forming compositionally distinct rims during greenschist and amphibolite facies
metamorphism at 1.2 Ga. Diagenetic xenotime is present in lower greenschist facies samples, but was not observed in metasedimentary
rocks that had experienced temperatures above mid-greenschist facies metamorphism (450°C). The apparent disappearance of detrital
and diagenetic xenotime and appearance of metamorphic xenotime during prograde metamorphism indicates that some of the yttrium,
heavy rare earth elements, and phosphorus needed for metamorphic xenotime growth are probably derived from the replacement
of detrital and diagenetic xenotime. 相似文献