57 research outputs found
Macrofossils and pollen representing forests of the pre-Taupo volcanic eruption (c. 1850 yr BP) era at Pureora and Benneydale, central North Island, New Zealand.
No full textMicro- and macrofossil data from the remains of forests overwhelmed and buried at Pureora and Benneydale during the Taupo eruption (c. 1850 conventional radiocarbon yr BP) were compared. Classification of relative abundance data separated the techniques, rather than the locations, because the two primary clusters comprised pollen and litter/wood. This indicates that the pollen:litter/wood within-site comparisons (Pureora and Benneydale are 20 km apart) are not reliable. Plant macrofossils represented mainly local vegetation, while pollen assemblages represented a combination of local and regional vegetation. However, using ranked abundance and presence/absence data, both macrofossils and pollen at Pureora and Benneydale indicated conifer/broadleaved forest, of similar forest type and species composition at each site. This suggests that the forests destroyed by the eruption were typical of mid-altitude west Taupo forests, and that either data set (pollen or macrofossils) would have been adequate for regional forest interpretation.
The representation of c. 1850 yr BP pollen from the known buried forest taxa was generally consistent with trends determined by modern comparisons between pollen and their source vegetation, but with a few exceptions.
A pollen profile from between the Mamaku Tephra (c. 7250 yr BP) and the Taupo Ignimbrite indicated that the Benneydale forest had been markedly different in species dominance compared with the forest that was destroyed during the Taupo eruption. These differences probably reflect changes in drainage, and improvements in climate and/or soil fertility over the middle Holocene
The drivers and predictability of wildfire re-burns in the western United States (US)
No full textEvidence is mounting that the effectiveness of using prescribed burns as a management tactic may be diminishing due to the higher incidence of wildfire re-burns. The development of predictive models of re-burns is thus essential to better understand their primary drivers so that forest management practices can be updated to account for these events. First, we assess the potential for human activity as a driver of re-burns by evaluating re-burn trends both within and outside of the wildland–urban interface (WUI) of the western US. Next, we investigate the predictability of re-burns through the application of both random forest and the explanatory machine learning non-negative matrix factorization using k -means clustering (NMFk) algorithms to predict re-burn occurrence over California based on a number of climate factors. Our findings indicate that while most states showed increasing trends within the WUI when trends were conducted over longer moving windows (e.g. 20 years), California was the only state where the rate of increase was consistently higher in the WUI, indicating a stronger potential for human activity as a driver in that location. Furthermore, we find model performance was found to be robust over most of California (Testing F1 scores = 0.688), although results were highly variable based on EPA level III Ecoregion (F1 scores = 0.0–0.778). Insights provided from this study will lead to a better understanding of climate and human activity drivers of re-burns and how these vary at broad spatial scales so that improvements in forest management practices can be tuned according to the level of change that is expected for a given region
Oceanic Shoals Commonwealth Marine Reserve - Chlorophyll a, b and c and phaeophytin a concentrations in seabed sediments.
No full textMaintenance and Update Frequency: asNeededStatement: Bottom sediments were collected using either a Smith McIntyre grab or a Box Core. 0.4 ml samples of surface sediment (0-0.5 cm) were syringed into plastic bags. The samples were wrapped in Al foil and frozen. Chlorophyll concentrations were calculated on sediment extracts (90% acetone + 0.1% MgCO3) at spectrophometric readings at wavelengths of 647, 630, 750 and 664 nm. For chlorophyll-a (Chl-a) and phaeophytin-a, wavelengths of 664 nm and 750 nm (before and after the addition of 200 -L-1 0.1 mol L-1 HCl per 2 mL extractant) and the equation derived by Lorenzen (1967) were used. Chlorphyll b and c concentrations were calculated according to equations provided by Jeffrey and Welschmeyer (2003). The reproducibility of the measurements was +/-10%.
Thanks to the crew of the RV Solander for help with sample collection.
Lorenzen, C. J. (1967). Determination of chlorophyll and pheopigments: Spectrophotometric equations. Limnology and Oceanography 12, 343-346.
Jeffrey, S.W., and Welschmeyer, N.A. (2003). Spectrophotometric and fluorometric equations in common use in oceanography. In 'Phytoplankton pigments in oceanography: guidelines to modern methods' (Eds. S.W. Jeffrey and R.F.C. Mantoura, and S.W. Wright.) pp. 597-615. (UNESCO Paris.)This resource contains geochemistry data for the Oceanic Shoals Commonwealth Marine Reserve (CMR) in the Timor Sea collected by Geoscience Australia during September and October 2012 on RV Solander (survey GA0339/SOL5650). This datset comprises chlorophyll a, b and c and phaeophytin a concentrations from the upper 2 cm of seabed sediments. The Oceanic Shoals Commonwealth Marine Reserve survey was undertaken as an activity within the Australian Government's National Environmental Research Program Marine Biodiversity Hub and was the key component of Research Theme 4 - Regional Biodiversity Discovery to Support Marine Bioregional Plans. Hub partners involved in the survey included the Australian Institute of Marine Science, Geoscience Australia, the University of Western Australia, Museum Victoria and the Museum and Art Gallery of the Northern Territory. Data acquired during the survey included: multibeam sonar bathymetry and acoustic backscatter; sub-bottom acoustic profiles; physical samples of seabed sediments, infauna and epibenthic biota; towed underwater video and still camera observations of seabed habitats; baited video observations of demersal and pelagic fish, and; oceanographic measurements of the water column from CTD (conductivity, temperature, depth) casts and from deployment of sea surface drifters. Further information on the survey is available in the post-survey report published as Geoscience Australia Record 2013/38: Nichol, S.L., Howard, F.J.F., Kool, J., Stowar, M., Bouchet, P., Radke, L.,<br/>Siwabessy, J., Przeslawski, R., Picard, K., Alvarez de Glasby, B., Colquhoun, J., Letessier, T. &<br/>Heyward, A. 2013. Oceanic Shoals Commonwealth Marine Reserve (Timor Sea) Biodiversity Survey:<br/>GA0339/SOL5650 - Post Survey Report. Record 2013/38. Geoscience Australia: Canberra. (GEOCAT #76658)
Volatile aldehydes in libraries and archives
No full textVolatile aldehydes are produced during degradation of paper-based materials. This may result in their accumulation in archival and library repositories. However, no systematic study has been performed so far. In the frame of this study, passive sampling was carried out at ten locations in four libraries and archives. Despite the very variable sampling locations, no major differences were found, although air-filtered repositories were found to have lower concentrations while a non-ventilated newspaper repository exhibited the highest concentrations of volatile aldehydes (formaldehyde, acetaldehyde, furfural and hexanal). Five employees in one institution were also provided with personal passive samplers to investigate employees’ exposure to volatile aldehydes. All values were lower than the presently valid exposure limits.
The concentration of volatile aldehydes, acetic acid, and volatile organic compounds (VOCs) in general was also compared with that of outdoor-generated pollutants. It was evident that inside the repository and particularly inside archival boxes, the concentration of VOCs and acetic acid was much higher than the concentration of outdoor-generated pollutants, which are otherwise more routinely studied in connection with heritage materials. This indicates that further work on the pro-degradative effect of VOCs on heritage materials is necessary and that monitoring of VOCs in heritage institutions should become more widespread
Oceanic Shoals Commonwealth Marine Reserve - Bulk organic carbon and nitrogen concentrations and isotopes in seabed sediment.
No full textMaintenance and Update Frequency: asNeededStatement: Bottom sediments were collected using either a Smith McIntyre grab or a Box Core. Surface sediments (~0-2 cm) within the grab were spooned into falcon vials and the porewaters were removed by centrifugation. The samples were then frozen for transport to the laboratories at Geoscience Australia where they were freeze-dried, ground in a tungsten carbide mill and decarbonated. The decarbonated powders were sent to Environmental Isotopes Pty Ltd (Sydney) for isotopic analysis by mass spectrometry. Samples were back-corrected to account for the carbonate removal, using carbonate concentrations derived from the bomb method. Error estimates for the C and N isotope values are ±0.15. The carbonate measurements (used to back correct) were better than 5%.
Thanks to the crew of the RV Solander for help with sample collection. Environmental Isotopes Pty. Sydney provided the analyses after sample processing by T. Watson and with the administrative support of J. Chen.This resource contains geochemistry data for the Oceanic Shoals Commonwealth Marine Reserve (CMR) in the Timor Sea collected by Geoscience Australia during September and October 2012 on RV Solander (survey GA0339/SOL5650). This dataset comprises bulk organic carbon and nitrogen concentrations (and isotopes) from the upper 2 cm of seabed sediment. The Oceanic Shoals Commonwealth Marine Reserve survey was undertaken as an activity within the Australian Government's National Environmental Research Program Marine Biodiversity Hub and was the key component of Research Theme 4 - Regional Biodiversity Discovery to Support Marine Bioregional Plans. Hub partners involved in the survey included the Australian Institute of Marine Science, Geoscience Australia, the University of Western Australia, Museum Victoria and the Museum and Art Gallery of the Northern Territory. Data acquired during the survey included: multibeam sonar bathymetry and acoustic backscatter; sub-bottom acoustic profiles; physical samples of seabed sediments, infauna and epibenthic biota; towed underwater video and still camera observations of seabed habitats; baited video observations of demersal and pelagic fish, and; oceanographic measurements of the water column from CTD (conductivity, temperature, depth) casts and from deployment of sea surface drifters. Further information on the survey is available in the post-survey report published as Geoscience Australia Record 2013/38: Nichol, S.L., Howard, F.J.F., Kool, J., Stowar, M., Bouchet, P., Radke, L., Siwabessy, J., Przeslawski, R., Picard, K., Alvarez de Glasby, B., Colquhoun, J., Letessier, T. & Heyward, A. 2013. Oceanic Shoals Commonwealth Marine Reserve (Timor Sea) Biodiversity Survey: GA0339/SOL5650 - Post Survey Report. Record 2013/38. Geoscience Australia: Canberra. (GEOCAT #76658)
Corylus cornuta subsp. cornuta Marshall subsp. cornuta
No full text7a. Corylus cornuta Marshall subsp. cornuta Note: it has been recognized as having two subspecies by Flora of North America (Furlow 1997) and World Checklist and Bibliography of Fagales (Govaerts & Frodin 1998). C. rostrata Aiton, Hortus Kewensis 3: 364 (Aiton 1789). – Original citation: “Cult. [since] 1745 by Archibald Duke of Argyle” [sic!, Archibald Campbell, third Duke of Argyll, who laid the groundstock for Kew Botanical Gardens] and “Nat. of North America.” Material from the cited Gronovius (1762): “Crescit in Dragon swamps” [a river in Virginia, USA]. – Type: Cult., Hort. Bni [Botanici] Collinson, Mill Hill, s. coll., s.n. (neo-, designated here: BM001191197!). – Note: the first author did not find any original material in the relevant herbaria. In order to explore which material might be taken into account, we briefly discuss the origin of the name here. As there is no explicit indication of an author, the name is to be attributed to Aiton (Art 46.8. ICN, McNeill et al. 2012). However, the original author of C. rostrata is apparently Daniel Carlsson Solander. Although the third volume was mainly edited by Dryander (Stafleu & Cowan 1976 –1988), Dryander largely used Solander’s manuscripts (Britten 1912), and in the Linnean herbarium, there is a specimen of what is now understood as C. cornuta (LINN 1132.2) where J.E. Smith writes “ C. rostrata Mss. 83. 931” and “ C. rostrata Soland [er] Ait. H. Kew v.3 364.” As a contemporary of the publication, Smith likely knew who the author of the name was, while 81 and 931 might be interpreted as manuscript fragments. Therefore, possible original material needs to be linked to Solander’s collections. Two sources are cited in the protologue, material from Duke Argyll’s garden and Gronovius’ Flora Virginica ed. 2 (Gronovius 1762). Material from Gronovius is usually found in the Clayton Herbarium (Stafleu & Cowan 1976 –1988), but there appears to be no original material of this taxon. Also, the number cited for Clayton’s herbarium in Gronovius’ Flora Virginica ed. 2 is erroneous, because Clayton 747 is a Juglans sp., which is already cited on the previous page. There is a specimen in BM (BM001191197) by Peter Collinson (1694–1768) from Mill Hill, where Collinson lived from 1749 on (Living & Braithwaite 2013). Collinson obtained material from Gronovius for cultivation (Reveal & Pringle 1993), and Collinson was also in contact with Solander. Thus, the specimen might be derived from Gronovius’ collection. In addition, as a student of Linnaeus, Solander had access to his herbarium, so the LINN specimen (LINN 1132.2) might also be taken into consideration. However, neither Collinson’s specimen nor the one from the Linnean herbarium can unambiguously linked to Solander, so they are not original material, making a neotypification necessary. Due to be possible link and the completeness of the specimen, we choose the specimen from Collinson’s garden as neotype. C. cornuta f. inermis Fernald, Rhodora 38: 76 (Fernald 1936). – Original citation: “ Quebec: abundant in border of woods, East Broughton”. – Type: Canada, Quebec, East Broughton, 28 Aug. 1915, M.L. Fernald and H.B. Jackson 12073 (holo-: GH). C. cornuta var. megaphylla Vict. & Rousseau, Contributions de l’Institut Botanique de l’Universite de Montréal 36: 13 (Marie-Victorin & Rousseau 1940). – Type: Canada, Quebec, Matapédia, sur les îles de la Restigouche, à l’embouchure de la Matapédia (frontière du Nouveau-Brunswick), 15 Aug. 1928, J.L.C. Marie-Victorin and Rolland-Germain 28690 (lecto-, designated here: MT00132174!; isolecto-: MT00132175!). – Additional type material: Canada, Quebec, thickets and borders of woods, near mouth of Marsouin River (Gaspé Co.), 26 Jul. 1922, M.L. Fernald and A.S. Pease 25014 (syn-: MT00206842!). – Note: Marie-Victorin & Rousseau cited the two collections and mentioned that the type is in the herbarium of the Université de Montreal (MT). However, there are two specimens of Marie-Victorin and Rolland-Germain 28690 in MT, of which one is annotated as a type, and one specimen of Fernald and Pease 25014 (Geoffrey Hall, MT, pers. com.). The annotated specimen is here formally designated as lectotype.Published as part of Holstein, Norbert, Tamer, Sarah el & Weigend, Maximilian, 2018, The nutty world of hazel names - a critical taxonomic checklist of the genus Corylus (Betulaceae), pp. 1-45 in European Journal of Taxonomy 409 on page 21, DOI: 10.5852/ejt.2018.409, http://zenodo.org/record/378716
An investigation of the calcification response of the scleractinian coral Astrangia poculata to elevated pCO2 and the effects of nutrients, zooxanthellae and gender
No full text© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeosciences 9 (2012): 29-39, doi:10.5194/bg-9-29-2012.The effects of nutrients and pCO2 on zooxanthellate and azooxanthellate colonies of the temperate scleractinian coral Astrangia poculata (Ellis and Solander, 1786) were investigated at two different temperatures (16 °C and 24 °C). Corals exposed to elevated pCO2 tended to have lower relative calcification rates, as estimated from changes in buoyant weights. Experimental nutrient enrichments had no significant effect nor did there appear to be any interaction between pCO2 and nutrients. Elevated pCO2 appeared to have a similar effect on coral calcification whether zooxanthellae were present or absent at 16 °C. However, at 24 °C, the interpretation of the results is complicated by a significant interaction between gender and pCO2 for spawning corals.
At 16 °C, gamete release was not observed, and no gender differences in calcification rates were observed – female and male corals showed similar reductions in calcification rates in response to elevated CO2 (15% and 19% respectively). Corals grown at 24 °C spawned repeatedly and male and female corals exhibited two different growth rate patterns – female corals grown at 24 °C and exposed to CO2 had calcification rates 39% lower than females grown at ambient CO2, while males showed a non-significant decline of 5% under elevated CO2. The increased sensitivity of females to elevated pCO2 may reflect a greater investment of energy in reproduction (egg production) relative to males (sperm production). These results suggest that both gender and spawning are important factors in determining the sensitivity of corals to ocean acidification, and considering these factors in future research may be critical to predicting how the population structures of marine calcifiers will change in response to ocean acidification.This material is based upon work supported under a
National Science Foundation Graduate Research Fellowship, the
WHOI Ocean Life Institute, NSF OCE-1041106, and an International
Society for Reef Studies/Ocean Conservancy Fellowship
Adverse effects of ocean acidification on early development of squid (Doryteuthis pealeii)
No full textThis study was supported by a WHOI Student Summer Fellowship and WHOI-MIT Joint Program, the Penzance Endowed Fund, the John E. and Anne W. Sawyer Endowed Fund and NSF Research Grant No. EF-1220034. Additional support came from NSF OCE 1041106 to ALC and DCM, and NOAA Sea Grant award #NA10OAR4170083 to ALC and DCM.Anthropogenic carbon dioxide (CO2) is being absorbed into the ocean, altering seawater chemistry, with potentially negative impacts on a wide range of marine organisms. The early life stages of invertebrates with internal and external aragonite structures may be particularly vulnerable to this ocean acidification. Impacts to cephalopods, which form aragonite cuttlebones and statoliths, are of concern because of the central role they play in many ocean ecosystems and because of their importance to global fisheries. Atlantic longfin squid (Doryteuthis pealeii), an ecologically and economically valuable taxon, were reared from eggs to hatchlings (paralarvae) under ambient and elevated CO2 concentrations in replicated experimental trials. Animals raised under elevated pCO2demonstrated significant developmental changes including increased time to hatching and shorter mantle lengths, although differences were small. Aragonite statoliths, critical for balance and detecting movement, had significantly reduced surface area and were abnormally shaped with increased porosity and altered crystal structure in elevated pCO2-reared paralarvae. These developmental and physiological effects could alter squid paralarvae behavior and survival in the wild, directly and indirectly impacting marine food webs and commercial fisheries.Peer reviewe
Seafloor environments of the eastern Timor Sea, Northern Australia: Chlorophyll a,b,c and pheaophytin a concentrations in seabed sediments.
No full textMaintenance and Update Frequency: asNeededStatement: Sediments were collected using either a Smith-McIntyre grab or a Shipek grab. For chlorophylls, 0.4 ml samples of surface sediment (0-0.5 cm) were syringed into plastic bags. The samples were wrapped in Al foil and frozen. Chlorophyll concentrations were calculated on sediment extracts (90% acetone + 0.1% MgCO3) at spectrophometric readings at wavelengths of 647, 630, 750 and 664 nm. For chlorophyll-a (Chl-a) and phaeophytin-a, wavelengths of 664 nm and 750 nm (before and after the addition of 200 -L-1 0.1 mol L-1 HCl per 2 mL extractant) and the equation derived by Lorenzen (1967) were used. Chlorphyll b and c concentrations were calculated according to equations provided by Jeffrey and Welschmeyer (2003). The reproducibility of the measurements is expected to be +/-10%. Lorenzen, C. J. (1967). Determination of chlorophyll and pheopigments: Spectrophotometric equations. Limnology and Oceanography 12, 343-346. Jeffrey, S.W., and Welschmeyer, N.A. (2003).
Thanks to the crew of the RV Solander for help with sample collection.The Timor Sea and its tropical marine environment support significant and growing economic activity including oil and gas exploration. To reduce uncertainty in decision making regarding the sustainable use and ongoing protection of these marine resources, environmental managers and resource users require sound scientific information on the composition and stability of seabed environments and their biological assemblages. Surveys SOL4934 and SOL5117 to the eastern Joseph Bonaparte Gulf were undertaken in August and September 2009 and July and August 2010 respectively, in collaboration with the Australian Institute of Marine Science, with research collaborations from the RAN Australian Hydrographic Office, the Geological Survey of Canada and the Museum and Art Gallery of the Northern Territory. The purpose of these surveys were to develop biophysical maps, and deliver data and information products pertaining to complex seabed environment of the Van Diemen Rise and identify potential geohazards and unique, sensitive environments that relate to offshore infrastructure. This dataset comprises chlorophyll a,b, and c, and phaeophytin a concentrations in the upper 2cm of seafloor sediments.<br/><br/><br/>Some relevant publications are listed below:<br/><br/>1. Heap, A.D., Przeslawski, R., Radke, L., Trafford, J., Battershill, C. and Shipboard Party. 2010. Seabed environments of the eastern Joseph Bonaparte Gulf, Northern Australia: SOL4934 Post Survey Report. Geoscience Australia Record 2010/09, pp.81.<br/>2. Anderson, T.J., Nichol, S., Radke, L., Heap, A.D., Battershill, C., Hughes, M., Siwabessy, P.J., Barrie, V., Alvarez de Glasby, B., Tran, M., Daniell, J. & Shipboard Party, 2011b. Seabed Environments of the Eastern Joseph Bonaparte Gulf, Northern Australia: GA0325/Sol5117 - Post-Survey Report. Geoscience Australia, Record 2011/08, 58pp.<br/>3. Radke, L.C., Li, J., Douglas, G., Przeslawski, R., Nichol, S, Siwabessy, J., Huang, Z., Trafford, J., Watson, T. and Whiteway, T. Characterising sediments of a tropical sediment-starved continental shelf using cluster analysis of physical and geochemical variables. Environmental Chemistry, in pres
Seabed environments and shallow geology of the Leveque Shelf, Browse Basin, Western Australia - Chlorophyll a, b, and c and phaeophytin a of seabed sediments.
No full textMaintenance and Update Frequency: asNeededStatement: Bottom sediments were collected using either a Smith Macintyre grab or a Shipek grab. 0.4 ml samples of surface sediment (0-0.5 cm) were syringed into plastic bags. The samples were wrapped in Al foil and frozen. Chlorophyll concentrations were calculated on sediment extracts (90% acetone + 0.1% MgCO3) at spectrophometric readings at wavelengths of 647, 630, 750 and 664 nm. For chlorophyll-a (Chl-a) and phaeophytin-a, wavelengths of 664 nm and 750 nm (before and after the addition of 200 -L-1 0.1 mol L-1 HCl per 2 mL extractant) and the equation derived by Lorenzen (1967) were used. Chlorphyll b and c concentrations were calculated according to equations provided by Jeffrey and Welschmeyer (2003). The reproducibility of the measurements is +/-10%.
Lorenzen, C. J. (1967). Determination of chlorophyll and pheopigments: Spectrophotometric equations. Limnology and Oceanography 12, 343-346.
Jeffrey, S.W., and Welschmeyer, N.A. (2003). Spectrophotometric and fluorometric equations in common use in oceanography. In 'Phytoplankton pigments in oceanography: guidelines to modern methods' (Eds. S.W. Jeffrey and R.F.C. Mantoura, and S.W. Wright.) pp. 597-615. (UNESCO Paris.)
Thanks to the crew of the RV Solander for help with sample acquisition.Geoscience Australia undertook a marine survey of the Leveque Shelf (survey number SOL5754/GA0340), a sub-basin of the Browse Basin, in May 2013. This survey provides seabed and shallow geological information to support an assessment of the CO2 storage potential of the Browse sedimentary basin. The basin, located on the Northwest Shelf, Western Australia, was previously identified by the Carbon Storage Taskforce (2009) as potentially suitable for CO2 storage. The survey was undertaken under the Australian Government's National CO2 Infrastructure Plan (NCIP) to help identify sites suitable for the long term storage of CO2 within reasonable distances of major sources of CO2 emissions. The principal aim of the Leveque Shelf marine survey was to look for evidence of any past or current gas or fluid seepage at the seabed, and to determine whether these features are related to structures (e.g. faults) in the Leveque Shelf area that may extend to the seabed. The survey also mapped seabed habitats and biota to provide information on communities and biophysical features that may be associated with seepage. This research, combined with deeper geological studies undertaken concurrently, addresses key questions on the potential for containment of CO2 in the basin's proposed CO2 storage unit, i.e. the basal sedimentary section (Late Jurassic and Early Cretaceous), and the regional integrity of the Jamieson Formation (the seal unit overlying the main reservoir). This dataset comprises total chlorin concentrations and chlorin indices from the upper 2cm of seabed sediments
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