Rising atmospheric CO2 reduces sequestration of root-derived soil carbon     

Heath J  Ayres E  Possell M  Bardgett RD  Black HI  Grant H  Ineson P  Kerstiens G 《Science (New York, N.Y.)》2005,309(5741):1711-1713

Forests have a key role as carbon sinks, which could potentially mitigate the continuing increase in atmospheric carbon dioxide concentration and associated climate change. We show that carbon dioxide enrichment, although causing short-term growth stimulation in a range of European tree species, also leads to an increase in soil microbial respiration and a marked decline in sequestration of root-derived carbon in the soil. These findings indicate that, should similar processes operate in forest ecosystems, the size of the annual terrestrial carbon sink may be substantially reduced, resulting in a positive feedback on the rate of increase in atmospheric carbon dioxide concentration.  相似文献   

Quantifying links between instream woody habitat and freshwater fish species in south‐eastern Australia to inform waterway restoration     

Zeb Tonkin  Adrian Kitchingman  Ben Fanson  Jarod Lyon  Renae Ayres  Joanne Sharley  Wayne M. Koster  Justin O'Mahony  Graeme Hackett  Paul Reich  Robin Hale 《水产资源保护:海洋与淡水生态系统》2020,30(7):1385-1396

1. Removal of instream woody habitat (IWH) is one factor attributed to declines in fish populations worldwide. Restoration of IWH to help fish populations recover is now common; however, quantitative predictions about the outcomes of these interventions is rare. As such, quantitative links between IWH and fish abundance is of interest to managers to inform conservation and restoration activities.
2. Links between instream habitat attributes, especially IWH, and selected fish species of recreational, cultural, and ecological significance were explored at 335 sites spanning eight streams across south‐eastern Australia. Data were collected on fish abundance and length, IWH density and a range of other habitat attributes at a scale that incorporated at least one of each of the major mesohabitat types (functional river elements). The data were analysed using Bayesian hierarchical generalized linear mixed models to examine fish habitat associations and used to make quantitative predictions of responses to future restoration.
3. Strong positive relationships were found between fish abundance and IWH density and the strength of this relationship varied between species and waterways. Murray cod (Maccullochella peelii), a species commonly targeted by IWH interventions, displayed the strongest association with IWH density. River blackfish (Gadopsis marmoratus) also showed a significant relationship with IWH, but this effect was waterway specific. Fish length was only related to IWH for river blackfish. These results may reflect differences in the life histories of these two species. We suggest that differences in habitat association through ontogeny may be more relevant at smaller spatial scales.
4. The results generated in this study can be used to guide waterway restoration and develop quantitative predictions about how fish might respond to IWH interventions across south‐eastern Australia. This approach provides a powerful quantitative framework within which to explore management options and objectives, and to test our predicted responses to habitat restoration.

  相似文献   

Sprout inhibition of table stock potatoes with CIPC-treated paper bags     

R. E. Nylund  L. C. Ayres 《American Journal of Potato Research》1964,41(11):341-348

  相似文献   

Surgical treatment of tracheal collapse using pliable total ring prostheses: results in one experimental and 4 clinical cases          下载免费PDF全文

Ayres SA  Holmberg DL 《The Canadian veterinary journal. La revue veterinaire canadienne》1999,40(11):787-791

Pliable total ring prostheses were created from the polyvinyl chloride drip chambers of intravenous administration sets. The total ring prostheses were placed in one clinically normal research dog and in 4 client-owned dogs diagnosed with tracheal collapse. The research dog was euthanized one month after placement of the prostheses. Histopathological analysis of the trachea adjacent to the prostheses revealed a mild inflammatory response. The follow-up period for the clinical cases was from 4 months to 11 years. Radiographs taken and fluoroscopy performed 1 day to 5 months after surgery revealed improvement or resolution of the tracheal collapse. One dog was asymptomatic 28 weeks following surgery. Two dogs died 7 and 9 years after surgery, with one requiring intermittent medical management for coughing. They were euthanized for nonrespiratory illness. One dog had a persistent nonproductive cough, due to collapse of the mainstem bronchi, when last evaluated 4 months postoperatively. Pliable total ring prostheses provided adequate stability to the trachea and had the advantage of conforming to the trachea and being easy to create, place, and suture.  相似文献   

The effect of a dacitic (rhyolitic) tuff breccia (Azomite®) in corn,soybean, and DDGS based diets that vary in inorganic phosphate source on pellet mill energy use, 0 to 21-day broiler performance,and apparent ileal amino acid digestibility     

K.M. Bowen  T.P. Boltz  J. Ferrel  V.E. Ayres  J.S. Moritz 《The Journal of Applied Poultry Research》2022,31(3):100259

  相似文献   

Liveweight gain of beef cattle in Brachiaria brizantha pastures and mixtures with Stylosanthes guianensis in the Brazilian savannah     

Gustavo José Braga  Allan Kardec Braga Ramos  Marcelo Ayres Carvalho  Carlos Eduardo Lazarini Fonseca  Francisco Duarte Fernandes  Celso Dornellas Fernandes 《Grass and Forage Science》2020,75(2):206-215

The use of stylosanthes in mixed grass-legume pastures may minimize the decline in forage quality and quantity that occurs in monoculture grass pastures, even though the availability of commercial cultivars in Brazil is still limited. The objective of the study was to evaluate the liveweight (LW) gain of young Nellore bulls in a mixed pasture of Brachiaria brizantha (cv. Paiaguás) with the latest release Stylosanthes guianensis cv. Bela. The study was conducted in Planaltina, FD, Brazil, from September to August in two consecutive years, right after seeding. The experimental design was a randomized complete block design with two treatments (mixed or monoculture Paiaguás pastures) and three replicates. The average daily gain (ADG) was on average greater in mixed pastures (0.436 vs. 0.350 kg head⁻¹ day⁻¹ in mixed and grass pastures respectively), particularly in the dry period (0.344 vs. 0.183 kg head⁻¹ day⁻¹). The benefit of mixed over monoculture grass pastures throughout the year was 22 kg LW/head and 55 kg LW/ha. The presence of stylosanthes increased the crude protein (CP) concentration in mixed pastures (120 g/kg) when compared to monoculture grass pastures (109 g/kg), probably influencing the ADG of bulls. The increase of liveweight gain, predominantly in the dry season, makes the high-protein stylosanthes cv. Bela an alternative to buffer the seasonal deficit of forage quality in newly seeded grass pastures.  相似文献   

Development of microsatellite markers and evaluation of genetic diversity of the Amazonian ornamental fish Pterophyllum scalare     

Pandolfi  Victor César Freitas  Yamachita  Andrei Lincoln  de Souza  Felipe Pinheiro  de Godoy  Sara Mataroli  de Lima  Ed Christian Suzuki  Feliciano  Daniele Cassiano  de Pádua Pereira  Ulisses  Povh  Jayme Aparecido  Ayres  Denise Rocha  Bignardi  Annaiza Braga  Penafort  Jefferson Murici  de Fátima Ruas  Claudete  Lopera-Barrero  Nelson Mauricio 《Aquaculture International》2021,29(6):2435-2449

The objective of the present work was to develop species-specific microsatellite markers for P. scalare and to analyze the diversity and genetic structure of a wild population, from the Amazon River, and three commercial stocks (common, marble, and clown morphological variants), from farmers in Vieras-Minas Gerais. Through microsatellite-enriched genetic libraries, 11 microsatellite markers with adequate amplification patterns were characterized. Population genetic analysis identified eight polymorphic loci that generated 66 alleles ranging from two alleles (PSCA1B3) to nine (PSCA2H1). The polymorphic information content ranged from 0.031 to 0.827. High genetic differentiation was observed between the wild population and the stocks, and moderate differentiation between the three stocks. Deviation in the Hardy-Weinberg equilibrium was observed in one locus in the wild population, in five loci in the common morphological variant, in two in the marble, and in two in the clown morphological variant. Bayesian analysis of genetic structure revealed the existence of two clusters, one represented by the natural population and the other by the stocks. The developed microsatellite markers serve as a tool for the analysis of diversity and genetic structure and conservation studies of P. scalare.

  相似文献   

Home-field advantage accelerates leaf litter decomposition in forests     

Edward Ayres  Heidi Steltzer  Rodney T. Simpson  Matthew D. Wallenstein  William J. Parton  Diana H. Wall 《Soil biology & biochemistry》2009,41(3):606-610

Several leaf litter decay studies have indicated that decomposition occurs more rapidly when litter is placed beneath the plant species from which it had been derived than beneath a different plant species (i.e. home-field advantage, HFA), although support for this notion has not been universal. We provide the first quantification of HFA in relation to leaf litter decomposition using published litter mass loss data from forest ecosystems in North America, South America, and Europe. Our findings indicate that HFA is widespread in forest ecosystems; on average litter mass loss was 8% faster at home than away. We hypothesize that HFA results from specialization of the soil biotic community in decomposing litter derived from the plant above it. Climate and initial litter quality data can be used to explain about 70% of the variability in litter decomposition at a global scale, leaving about 30% unexplained. We suggest that HFA be recognized as a factor that explains some of this remaining variability.  相似文献   

Linking breeding and wintering ranges of a migratory songbird using stable isotopes     

Rubenstein DR  Chamberlain CP  Holmes RT  Ayres MP  Waldbauer JR  Graves GR  Tuross NC 《Science (New York, N.Y.)》2002,295(5557):1062-1065

We used the natural abundance of stable isotopes (carbon and hydrogen) in the feathers of a neotropical migrant songbird to determine where birds from particular breeding areas spend the winter and the extent to which breeding populations mix in winter quarters. We show that most birds wintering on western Caribbean islands come from the northern portion of the species' North American breeding range, whereas those on more easterly islands are primarily from southern breeding areas. Although segregated by breeding latitude, birds within local wintering areas derive from a wide range of breeding longitudes, indicating considerable population mixing with respect to breeding longitude. These results are useful for assessing the effects of wintering habitat loss on breeding population abundances and for predicting whether the demographic consequences will be concentrated or diffuse.  相似文献   

Water proposals for new york     

McCrone AW  Ayres RU  Lamort H  Neef WI  Merrill ET 《Science (New York, N.Y.)》1966,154(3746):215-216

  相似文献