A Revised Proposal for Errors and Emendations in the Rules of Zoological Nomenclature     

Blackwelder RE  Knight JB  Sabrosky CW 《Science (New York, N.Y.)》1948,108(2793):37-38

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Soil carbon and nitrogen response to 25 annual cattle manure applications     

Xiying Hao  Chi Chang  Greg R. Travis  Fengrong Zhang 《植物养料与土壤学杂志》2003,166(2):239-245

Improving manure management to benefit both agricultural production and the environment requires a thorough understanding of the long‐term effects of applied manure on soil properties. This paper examines the effect of 25 annual solid cattle manure applications on soil organic carbon (OC), total N (TN), and KCl‐extractable NO₃‐N and NH₄‐N under both non‐irrigated and irrigated conditions. After 25 annual manure applications, OC and TN contents increased significantly with the rate of manure application at the top two sampling depths (0–15 cm and 15–30 cm), and the increases were not affected by the irrigation treatment. The NO₃ content increased at all sampling depths with greater increases observed under non‐irrigated conditions, while NH₄ content was not affected by manure application rates or the irrigation treatment. The changes in OC and TN at the surface (0–15 cm) and 15–30 cm depth were dependent on the cumulative weight of manure added over the years. The relationships between cumulative manure OC added and soil OC content and between cumulative manure TN added and soil TN content were linear and not affected by the irrigation treatment. For every ton of manure OC added, soil OC increased by 0.181 g kg^–1 in the topsoil (0–15 cm). Similarly, for every ton of manure TN added, surface soil TN increased by 0.192 g kg^–1. The linear relationship between manure C added and soil C content suggests that the soil had a high capacity for short‐term C sequestration. However, the total amount of NO₃‐N in the soil profile (0–150 cm) was affected by both the manure application rates and the irrigation treatment. A large amount of NO₃ accumulated in the soil, especially under non‐irrigated conditions. The extremely high level of NO₃ in the soil increases the potential risk of surface and groundwater pollution and losses to atmosphere as N₂O.  相似文献   

Effect of long‐term cattle manure application on relations between nitrogen and oil content in canola seed     

Xiying Hao    Chi Chang  Greg J. Travis 《植物养料与土壤学杂志》2004,167(2):214-215

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Structure-dependent phytotoxicity of catechins and other flavonoids: flavonoid conversions by cell-free protein extracts of Centaurea maculosa (spotted knapweed) roots   总被引：2，自引：0，他引：2  

Bais HP  Walker TS  Kennan AJ  Stermitz FR  Vivanco JM 《Journal of agricultural and food chemistry》2003,51(4):897-901

Invasive plants are believed to succeed in part by secretion of allelochemicals, thus displacing competing plant species. Centaurea maculosa (spotted knapweed) provides a classic example of this process. We have previously reported that spotted knapweed roots secrete (+/-)-catechin and that (-)-catechin, but not (+)-catechin, is phytotoxic and hence may be a major contributor to C. maculosa's invasive behavior in the rhizosphere. In this communication, we explore both structure/activity relationships for flavonoid phytotoxicity and possible biosynthetic pathways for root production of (+/-)-catechin. Kaempferol and dihydroquercetin were shown to be phytotoxic, while quercetin was not. Kaempferol was converted to dihydroquercetin and (+/-)-catechin when treated with total root protein extracts from C. maculosa, but quercetin was not. This finding suggests an alteration in the standard flavonoid biosynthetic pathway in C. maculosa roots, whereby kaempferol is not a dead-end product but serves as a precursor to dihydroquercetin, which in turn leads to (+/-)-catechin production.  相似文献   

Orangutan movement and population dynamics across human-modified landscapes: implications of policy and management     

Seaman  Dave J. I.  Voigt  Maria  Bocedi  Greta  Travis  Justin M. J.  Palmer  Stephen C. F.  Ancrenaz  Marc  Wich  Serge  Meijaard  Erik  Bernard  Henry  Deere  Nicolas J.  Humle  Tatyana  Struebig  Matthew J. 《Landscape Ecology》2021,36(10):2957-2975

Landscape Ecology - Agricultural expansion is a leading cause of deforestation and habitat fragmentation globally. Policies that support biodiversity and facilitate species movement across farmland...  相似文献   

Density-dependent habitat selection and the ideal free distribution in marine fish spatial dynamics: considerations and cautions   总被引：3，自引：0，他引：3  

Travis D Shepherd  & Matthew K Litvak 《Fish and Fisheries》2004,5(2):141-152

Current methods and theory used in the study of the spatial dynamics of marine fish are problematic. Positive relationships between population abundance and occupied area are typically interpreted as evidence of density‐dependent habitat selection. However, both abundance and area may co‐vary with an un‐parameterized variable, such as a density‐independent effect. In addition, if density‐dependent habitat selection is present, population growth rates in optimal habitats would be expected to be lower than in marginal habitats. This same pattern can also evolve from a large‐scale, spatially autocorrelated change in a density‐independent factor. The theory underlying density‐dependent habitat selection, the ideal free distribution, can be tautological when no a priori information of how habitat suitability changes with density is known. In this case, an ideal free distribution can be defined for any pattern of habitat‐specific population growth rates. However, these problems are not insurmountable and solutions may be found by considering spatial variation in proxies of fitness and explicitly allowing for the relative importance of habitat selection (density dependent) and environmental (density independent) effects to vary with spatial scale.  相似文献   

Seasonal use of a macrotidal estuary by the endangered dwarf sawfish,Pristis clavata     

David L. Morgan  Karissa O. Lear  Emma Dobinson  Adrian C. Gleiss  Travis Fazeldean  Richard D. Pillans  Stephen J. Beatty  Jeff M. Whitty 《水产资源保护:海洋与淡水生态系统》2021,31(8):2164-2177

1. Sawfishes (Family: Pristidae) are one of the most imperilled fish families worldwide. There is an increasingly urgent need to better understand the biology, ecology, and population status of the five sawfish species to develop more effective conservation measures. The dwarf sawfish, Pristis clavata, is one of the least researched members of the pristids, with literature limited to analysing disparate datasets or collations of rare encounters in northern Australia.
2. This study examined the spatial ecology of dwarf sawfish using targeted surveys and acoustic telemetry to determine its habitat use in a macrotidal estuary in northern Australia. Seventeen dwarf sawfish were tagged with acoustic transmitters and monitored in the Fitzroy River estuary and adjacent King Sound (Kimberley, Western Australia) between August 2015 and November 2017.
3. Dwarf sawfish observed within the Fitzroy River estuary and King Sound were juveniles, ranging between 740 and 2,540 mm in total length. Catch per unit effort of dwarf sawfish in the late dry season was relatively high in the estuary, with the catch rate in 2015 being one of the highest reported for any sawfish species.
4. Acoustic detections revealed a distinct seasonal pattern in the use of different parts of the estuary and King Sound, which was found to be driven by salinity. Dwarf sawfish predominately occupied a single large pool near the terminus of the tidal limit in the late dry season (August–November), before transitioning to regions in closer proximity to the river mouth or in King Sound in the wet and early dry seasons (December–July).
5. Given the high abundance and residency of dwarf sawfish in the Fitzroy River estuary, this area is an important nursery for the species during the late dry season and should be formally recognized as a habitat protection area for the species.

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Nitrogen mineralization in boreal forest stands of isle royale,Northern Michigan     

R. Stottlemyer  B. Travis  D. Toczydlowski 《Water, air, and soil pollution》1995,82(1-2):191-202

The correlation of soil temperature and moisture with inorganic N concentrations and net mineralization beneath major species types in mature boreal and northern hardwood forests was examined over a two year period. Soils beneath species types where the canopy was dominated byBetula papyrifera, Picea glauca, Alnus rugosa or, in northern hardwoods,Acer saccharum were studied. Net NO₃ ^? mineralization varied by species type and net total inorganic nitrogen (N) mineralization varied by month and the interaction of species type with month. Soil NO₃ ^? concentration and NO₃ ^? mineralization were correlated for spruce, and inversely correlated for alder and maple. Soil NH₄ ⁺ concentration and NH₄ ⁺ mineralization were inversely correlated for alder and maple. In laboratory temperature and moisture treatments of birch, spruce and maple soils, NH₄ ⁺ and total inorganic N-mineralization increased with temperature. The response to moisture was most evident for NO₃ ^? mineralization in maple soils.  相似文献   

Racing prognosis after cumulative stress-induced injury of the distal portion of the third metacarpal and third metatarsal bones in Thoroughbred racehorses: 55 cases (2000-2009)     

Tull TM  Bramlage LR 《Journal of the American Veterinary Medical Association》2011,238(10):1316-1322

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Effect of Leaf Sugar and Starch Concentrations on Apparent Photosynthesis in Alfalfa     

R. L. Travis  J. Prendergast 《Journal of Agronomy and Crop Science》1987,159(1):51-58

Rates of apparent photosynthesis (AP), dark respiration, photorespiration, mesophyll resistance, and concentrations of soluble starch, sugars, chlorophyll and nitrogen were measured in alfalfa leaves ( Medicago sativa L.) grown under high or low light levels in an attempt to evaluate the effect of nonstructural carbohydrate concentration on net CO₂ assimilation.
Leaf N and chlorophyll levels of high light plants exceeded those of low-light plants. Constant light increased both starch and sugar levels in low-light plants, but had little effect on high-light plants. Rates of AP declined in low-light plants upon transfer to constant light conditions, apparently due to increases in stomatal and mesophyll resistance. Leaf starch levels were negatively correlated (P > 0.05) with rates of AP and positively correlated with mesophyll resistance in both groups of plants but leaf sugar content was not correlated with either AP or mesophyll resistance.
Starch and sugar levels of high-light plants declined substantially upon transfer to constant darkness, while low-light plants were less affected. Rates of AP declined in both groups of plants due to increases in both mesophyll and stomatal resistances. Neither sugar nor starch levels were correlated with AP or mesophyll conductance in this treatment.
The data support the hypothesis of feedback inhibition of photosynthesis, mediated through an increase in mesophyll resistance, which is associated with high levels of starch in the leaves.  相似文献