Changes in dissolved organic matter with depth suggest the potential for postharvest organic matter retention to increase subsurface soil carbon pools   总被引：3，自引：0，他引：3  

Brian D. Strahm  Robert B. Harrison  Thomas A. Terry  Timothy B. Harrington  A.B. Adams  Paul W. Footen 《Forest Ecology and Management》2009

Research into postharvest management of forests often focuses on balancing the need for increased biomass yield against factors that may directly impact the productivity of the subsequent stand (e.g. nutrient and water availability, soil microclimate, etc.). Postharvest organic matter management, however, also exerts a strong influence over the translocation of carbon (C) into and through the soil profile and may provide a mechanism to increase soil C content. The effects of contrasting postharvest organic matter retention treatments (bole-only removal, BO; whole-tree removal, WT) on soil solution C concentration and quality were quantified at the Fall River and Matlock Long-term Soil Productivity (LTSP) studies in Washington state. Solutions were collected monthly at depths of 20 and 100 cm and analyzed for dissolved organic C (DOC), dissolved organic nitrogen (DON) and DOC:DON ratio. Comparisons of DOC concentrations with depth illustrate divergent trends between the two treatments, with an overall decrease in DOC with depth in the BO treatment and either an increase or no change with depth in the WT treatment. Trends in DON concentrations with depth were less clear, partly due to the very low concentrations observed, although the relationship of DOC:DON with depth shows a decrease in the BO treatment and little to no change in DOC quality in the WT treatment. This illustrates that more recalcitrant organic matter (higher DOC:DON) is being removed from solution as it moves through the soil profile. Only 35–40% of the DOC moving past 20 cm in the BO treatment is present at 100 cm. Conversely, 98–117% of the DOC at 20 cm in the WT treatment is present at 100 cm. Thus, 11 and 30 kg C ha⁻¹ yr⁻¹ are removed from solution between 20 and 100 cm in the BO treatment at the Matlock and Fall River LTSP studies, respectively. Although much of this C is often assumed to be utilized for microbial respiration, DOC:DON ratios of the potential organic substrates and the unique mineralogy of the soils of this region suggest that a significant portion may in fact be incorporated into a more recalcitrant soil C pool. Thus, postharvest organic matter retention may provide a mechanism to increase soil C sequestration on these soils.  相似文献   

Lipopolysaccharide extraction: a phenol alternative     

R M L Gratacap  K D Thompson  I R Bricknell  A Adams 《Journal of fish diseases》2009,32(9):811-814

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Morphological and ecological responses to a conservation translocation of powan (Coregonus lavaretus) in Scotland     

E. C. Etheridge  C. W. Bean  P. S. Maitland  C. E. Adams 《水产资源保护:海洋与淡水生态系统》2010,20(3):274-281

• 1. The establishment of refuge populations has become a common management tool for threatened fish species in recent years, yet the effects of translocation are not fully understood in a conservation context.
• 2. This paper examines the hypothesis that phenotypic changes have occurred during the formation of two refuge populations of the nationally rare powan (a freshwater fish species) which were established in Loch Sloy and Carron Valley Reservoir in Scotland.
• 3. Significant differences in head morphology, size and growth between the founder and refuge populations and between the two refuge populations were demonstrated. These changes are probably due to a combination of founder effects, intense selection and phenotypic plasticity. These changes can undermine the rationale behind the establishment of refuge populations.
• 4. The results call into question the usefulness of translocation as a conservation measure; however, there are times when this is the only viable management option available. The future of translocation and the validity of establishing refuge populations for powan conservation are discussed. Copyright © 2010 John Wiley & Sons, Ltd.

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Estimation of metademographic rates and landscape connectivity for a conservation-reliant anuran     

Duarte  Adam  Peterson  James T.  Pearl  Christopher A.  Rowe  Jennifer C.  McCreary  Brome  Galvan  Stephanie K.  Adams  Michael J. 《Landscape Ecology》2020,35(6):1459-1479

Landscape Ecology - Amphibian conservation efforts commonly assume populations are tied to waterbodies that collectively function as a metapopulation. This assumption is rarely evaluated, and there...  相似文献   

Evaluation of the INNO‐LiPA mycobacteria v2 assay for identification of aquatic mycobacteria     

F Pourahmad  K D Thompson  J B Taggart  A Adams  R H Richards 《Journal of fish diseases》2008,31(12):931-940

Fifty‐seven isolates of mycobacteria comprising 10 reference strains, 47 field isolates and one non‐Mycobacterium isolate were screened using commercial INNO‐LiPA v2 assay kits. All mycobacteria isolates tested hybridized with the Mycobacterium genus probe on the LiPA strip. All M. marinum, M. fortuitum and M. chelonae reference and field strains and three out of the four M. gordonae isolates hybridized to their corresponding species‐ or complex‐specific probes. Two cultures (a type strain and a field isolate) yielded mixed growth of two mycobacterial species, i.e. M. chelonae and M. fortuitum. A Mycobacterium isolate from one of these cultures was subsequently purified and correctly identified with the kit. However, sequence analysis of the 16S–23S rRNA internal transcribed spacer (ITS) region of various mycobacteria isolates revealed a misidentification of M. shottsii and M. pseudoshottsii with the kit because these isolates reacted with the M. marinum/M. ulcerans probe. Moreover, nine of the 13 field isolates presumed to be M. fortuitum from the results of the kit had closer ITS sequence homology with M. conceptionense, a species which, to our knowledge, has never been reported in fish. These findings highlight the need to redesign the M. fortuitum–M. peregrinum probe included in the INNO‐LiPA assay and to introduce additional complex‐specific probes into the kit. Nevertheless, the kit proved to be a rapid and reliable method for identifying mycobacteria in the aquatic environment and would be particularly useful in laboratories without sequencing facilities.  相似文献   

An opportunistic detection of amoebic gill disease in blue warehou, Seriolella brama Günther, collected from an Atlantic salmon, Salmo salar L., production cage in south eastern Tasmania     

Adams MB  Villavedra M  Nowak BF 《Journal of fish diseases》2008,31(9):713-717

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Potato aphid control studies, 1946–1949, at Woodstock,N. B., Canada     

J. B. Adams  R. A. Kelley 《American Journal of Potato Research》1950,27(5):175-182

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Development of an in vivo assay to assess attachment of Neoparamoeba sp. (an amphizoic gymnamoeba) to the gills of Atlantic salmon, Salmo salar L     

Crosbie PB  Adams MB  Attard MG  Nowak BF 《Journal of fish diseases》2007,30(3):187-190

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Biotech Bits     

Kevin Adams 《Journal Of Agricultural & Food Information》2013,14(1):51-56

Predicts the emergence of a worldwide global change information network. Provides a summary of four entities that may become the leader in the creation of this future network.  相似文献   

Temporal and spatial dynamics of fish community structure during watershed alteration in two Ouachita River systems     

Aaron A. Burgad  Ginny L. Adams  Reid Adams 《Ecology of Freshwater Fish》2019,28(3):459-472

Fish community composition is highly dynamic, but generally exhibits loose equilibrium within bounds of community structure in upland stream systems with minimal anthropogenic disturbance. Chronic anthropogenic disturbance can exceed ecological thresholds and shift fish community composition to an alternative state. Therefore, long‐term datasets are critical to understand spatiotemporal dynamics of fish community structure. We quantified temporal changes in fish communities in two Ouachita River systems during watershed alteration (i.e., development and reservoir construction) using a suite of multivariate and univariate analyses to assess changes in fish community structure and taxonomic and functional β‐diversity. We found fish community composition shifted in the Saline River basin possibly in response to human disturbance (e.g., development) and hydrologic variability. Furthermore, functional homogenisation occurred through time. In the Ouachita Headwaters basin, taxonomic homogenisation was evident and two fluvial specialists were not detected during the current period. Taxonomic and functional β‐diversity patterns were not consistent across basins demonstrating the complexity of biotic homogenisation. Our retrospective analyses showed human activities played a role in restructuring fish communities despite minimal invasion of exotic species. Ultimately, our study characterised fish community structure across snapshots of time and demonstrates the importance of increasing the frequency of sampling intervals and continuing long‐term collections with similar methods to enhance the understanding of community dynamics.  相似文献