World Production of Raw Materials
In: International affairs, Band 29, Heft 3, S. 353
ISSN: 1468-2346
11 Ergebnisse
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In: International affairs, Band 29, Heft 3, S. 353
ISSN: 1468-2346
In: The economic history review, Band 48, Heft 4, S. 829
ISSN: 1468-0289
In: Wildlife research, Band 43, Heft 6, S. 482
ISSN: 1448-5494, 1035-3712
Context The role of disturbance and its exclusion is fundamental to the conservation of threatened species. Aims We used the habitat accommodation model as a framework to investigate the importance of forest disturbance for the endangered Hastings River mouse, Pseudomys oralis, focusing on timber harvesting. Methods Our study comprised two separate surveys. We resurveyed old survey sites (n = 24) where the species was originally recorded as either present (logging excluded) or absent (subsequently logged). A second survey targeted trapping in high-quality habitat stratified by different times since logging. Finally, we analysed a 15-year trapping dataset targeting P. oralis to assess associations with co-occurring species. Key results The resurvey of old sites resulted in 12 P. oralis individuals being trapped, compared with 46 individuals in original surveys. Substantial declines were observed over time in transects where logging was excluded (60–82% decline), whereas there was little change at transects where P. oralis was not previously trapped and that were subsequently logged. The second survey yielded 27 P. oralis captures at post-logging sites assessed as high quality. Occupancy was very high (ψ = 0.93 ± 0.21) in transects logged 7–15 years ago and was 60% less in transects where logging was excluded for 35–45 years (ψ = 0.37 ± 0.22), whereas occupancy in transects logged 2–6 years ago was intermediate. This pattern of higher occupancy in logged areas was mirrored for the mean number of P. oralis trapped per transect. Ordination of habitat data showed an association of P. oralis with heath, mat-rushes and logs, whereas rats (Rattus and Melomys) were associated with ferns and shrubs. Camera traps revealed low background levels of predator presence. A negative exponential relationship was found between probability of occupancy of P. oralis and rat abundance from a 15-year trapping dataset (44 275 trap-nights), suggesting that rats may compete with P. oralis. Conclusions Our results supported the habitat accommodation model and suggested that disturbance is likely to influence the persistence of P. oralis. However, an interaction between predation and loss of cover from high-frequency disturbance (fire or intense grazing) cannot be excluded as a key threat. Implications Disturbance should be incorporated into the management of some species. Adaptive monitoring is recommended to assess alternative management regimes.
In: Wildlife research, Band 23, Heft 4, S. 517
ISSN: 1448-5494, 1035-3712
In: Wildlife research, Band 23, Heft 3, S. 373
ISSN: 1448-5494, 1035-3712
Predator scats were collected near colonies of the brush-tailed rock-wallaby, Petrogale penicillata, in
gorges near Armidale, New South Wales. Scat collection coincided with the two periods when these
macropodids are believed to be most vulnerable to predation: when juveniles vacate the pouch (September)
and when they disperse from natal home ranges (April). The ratio of known dingo to fox scats did not differ
significantly from 1 : 1 for each collection period. The most common dietary items identified in the scat
analysis were as follows: rabbits (in 30% of scats); swamp wallabies (21%); cattle (16%); and brushtail
possums (10%). Despite a visible abundance of P. penicillata in the study area, it occurred rarely (1%) in
the 342 canid scats collected, and no P. penicillata was detected in fox scats. While the collection and
analysis of predator scats does detect P. penicillata, it does not provide an efficient means of doing so and
is unlikely to be effective at detecting small populations of this species.
In: Wildlife research, Band 48, Heft 6, S. 521-530
ISSN: 1448-5494, 1035-3712
Abstract Context Forest harvest practices have the potential to alter habitat available to forest fauna. One aspect of harvesting practice that has received little research attention is the effect of multiple rotations on available habitat, and its use by fauna. Aims We examined one component of habitat that is critical to many taxa, coarse woody debris (CWD). In forests of north-eastern New South Wales, Australia, we aimed to assess whether harvest (moderate intensity for saw-logs) frequency influences CWD levels, and whether fauna activity on CWD varies with harvest frequency and with CWD attributes. Methods Using habitat surveys and camera trapping, we compared CWD quantity and quality in unharvested sites with those that had been harvested once, twice and three times, and assessed fauna use of CWD. Key results We found significantly greater volume of non-hollow CWD, and of medium-sized pieces (15–30 cm diameter), in sites harvested three times versus unharvested sites. Camera trapping showed that the activity and composition of fauna were similar across these harvest treatments. Our results also found that a broad range of fauna used a variety of logs, including large and small logs in various states of decay. Conclusions Consistent with other Australian studies, our results suggested that there are no detectable impacts of harvesting on hollow or large CWD. Further studies using radio-tracking or similar methods are needed to more comprehensively assess how CWD is used by fauna. Implications CWD was used broadly by a range of species and should be targeted for retention under ecologically sustainable forest management practices to ensure that it continues to be present in harvested landscapes. This is particularly important in places where an intensification of practices is being considered.
In: http://hdl.handle.net/2027/uc1.a0011955432
"The scope . of the classification is restricted to technique . It will exclude all subject-matter of statistical, commerical, and economic nature . The classification as here presented is but one-third of that already prepared."--p. 3. ; "Based upon co-operative research conducted by International Association of Printing House Craftsmen, Inc., Augustus E. Giegengack, chairman of the Research Commission, and the Division of Tests and Technical Control, United States Government Printing Office." ; Mode of access: Internet.
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In: http://hdl.handle.net/2027/ucm.5329131964
Mode of access: Internet. ; Sign.: [ ]3, B-I4, [ ]2.
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Concentrations of atmospheric carbon dioxide (CO2) have continued to increase whereas atmospheric deposition of sulphur and nitrogen has declined in Europe and the USA during recent decades. Using time series of flux observations from 23 forests distributed throughout Europe and the USA, and generalised mixed models, we found that forest-level net ecosystem production and gross primary production have increased by 1% annually from 1995 to 2011. Statistical models indicated that increasing atmospheric CO2 was the most important factor driving the increasing strength of carbon sinks in these forests. We also found that the reduction of sulphur deposition in Europe and the USA lead to higher recovery in ecosystem respiration than in gross primary production, thus limiting the increase of carbon sequestration. By contrast, trends in climate and nitrogen deposition did not significantly contribute to changing carbon fluxes during the studied period. Our findings support the hypothesis of a general CO2-fertilization effect on vegetation growth and suggest that, so far unknown, sulphur deposition plays a significant role in the carbon balance of forests in industrialized regions. Our results show the need to include the effects of changing atmospheric composition, beyond CO2, to assess future dynamics of carbon-climate feedbacks not currently considered in earth system/climate modelling. ; European Research Council Synergy grant [ERC-2013-SyG 610028-IMBALANCE-P]; Spanish Government grant [CGL2013-48074-P]; Catalan Government projects [SGR 2014-274, FI-2013]; Scientific Research - Flanders; Juan de la Cierva fellowship from the Spanish Ministry of Science and Innovation; GHG-Europe project; Australian Climate Change Science Programme ; This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.
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The following authors were omitted from the original version of this Data Descriptor: Markus Reichstein and Nicolas Vuichard. Both contributed to the code development and N. Vuichard contributed to the processing of the ERA-Interim data downscaling. Furthermore, the contribution of the co-author Frank Tiedemann was re-evaluated relative to the colleague Corinna Rebmann, both working at the same sites, and based on this re-evaluation a substitution in the co-author list is implemented (with Rebmann replacing Tiedemann). Finally, two affiliations were listed incorrectly and are corrected here (entries 190 and 193). The author list and affiliations have been amended to address these omissions in both the HTML and PDF versions. © 2021, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.
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Background: The COVID-19 pandemic has disrupted routine hospital services globally. This study estimated the total number of adult elective operations that would be cancelled worldwide during the 12 weeks of peak disruption due to COVID-19. Methods: A global expert response study was conducted to elicit projections for the proportion of elective surgery that would be cancelled or postponed during the 12 weeks of peak disruption. A Bayesian β-regression model was used to estimate 12-week cancellation rates for 190 countries. Elective surgical case-mix data, stratified by specialty and indication (surgery for cancer versus benign disease), were determined. This case mix was applied to country-level surgical volumes. The 12-week cancellation rates were then applied to these figures to calculate the total number of cancelled operations. Results: The best estimate was that 28 404 603 operations would be cancelled or postponed during the peak 12 weeks of disruption due to COVID-19 (2 367 050 operations per week). Most would be operations for benign disease (90·2 per cent, 25 638 922 of 28 404 603). The overall 12-week cancellation rate would be 72·3 per cent. Globally, 81·7 per cent of operations for benign conditions (25 638 922 of 31 378 062), 37·7 per cent of cancer operations (2 324 070 of 6 162 311) and 25·4 per cent of elective caesarean sections (441 611 of 1 735 483) would be cancelled or postponed. If countries increased their normal surgical volume by 20 per cent after the pandemic, it would take a median of 45 weeks to clear the backlog of operations resulting from COVID-19 disruption. Conclusion: A very large number of operations will be cancelled or postponed owing to disruption caused by COVID-19. Governments should mitigate against this major burden on patients by developing recovery plans and implementing strategies to restore surgical activity safely.
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