Ecosystem-based management in the Great Bear Rainforest     

Karen Price  Audrey Roburn  Andy MacKinnon 《Forest Ecology and Management》2009

Ecosystem-based management is the management system being applied to 6.4 million hectares of the coast of British Columbia, Canada, an area referred to as the Great Bear Rainforest. This approach, intended to manage for ecosystem integrity and community wellbeing, is similar in many respects to ecosystem management approaches elsewhere. However, several novel elements are involved in application of ecosystem-based management on British Columbia's coast: shifts in power that have led to increased aboriginal control and the formation of coalitions between groups that were formerly in opposition; development of explicit models relating management strategies to land-use objectives and separating knowledge from values; use of ecological thresholds and natural variability to establish management targets. Current management is based on transitional targets that differ from science-based targets. Many challenges remain in moving to full implementation of ecosystem-based management, including the difficulties involved in moving from one management model to a fundamentally different one, limited resources for implementation, dealing with complex systems, the lack of freely available multi-disciplinary data, and the difficulty of bringing concepts of uncertainty and risk into public policy discussions in a transparent manner.  相似文献   

Effects of Drain and Harvest Dates on Rice Sensory and Physicochemical Properties     

Elaine T. Champagne  Karen L. Bett‐Garber  James Thompson  Randall Mutters  Casey C. Grimm  Anna M. McClung 《Cereal Chemistry》2005,82(4):369-374

Timing of field draining and harvesting of rice with meteorological conditions can allow growers to foster conditions for high head rice yield (HRY). The effects of timing of draining and harvesting on rice sensory and physicochemical properties are not well understood. The objective of this study was to determine the effects of varying drain and harvest dates on the sensory and physicochemical properties of M‐202 grown in California under controlled field conditions. Drain date had a significant (P < 0.05), but very small, effect on amylose and protein contents, with amylose being highest at the late drain date and protein being the lowest at the early drain date. Breakdown and setback were lowest for early and normal drain dates, respectively; however, no significant (P > 0.05) differences in texture were measured as a result of these parameters being low. Drain date did not affect the volatile composition or flavor of the rice. Harvest date had no effect (P > 0.05) on amylose content and a significant (P < 0.05), but very small, effect on protein content. Harvesting at the earliest date (9/30) resulted in rice with higher setback and lower breakdown than at the last date (10/16) and, subsequently, the early harvested rice, when cooked, was harder, more cohesive, and absorbed less saliva in the mouth. However, the differences in texture measured by the panelists were very small and would possibly not be noticed by untrained palates. The lowest levels of the lipid oxidation products 1‐pentanol, hexanal, and nonanal occurred in rice with the lowest harvest moisture content (HMC): rice harvested on 10/13 and 10/16. Differences in levels of lipid oxidation products and branched chain hydrocarbons did not lead to significant (P > 0.05) differences in flavor. In summary, M‐202 demonstrated stable composition, physicochemical properties, flavor, and texture across drain and harvest dates.  相似文献   

Effects of Degree of Milling,Drying Condition,and Final Moisture Content on Sensory Texture of Cooked Rice     

Brenda G. Lyon  Elaine T. Champagne  Bryan T. Vinyard  William R. Windham  Franklin E. Barton  Bill D. Webb  Anna M. McClung  Karen A. Moldenhauer  Steve Linscombe  Kent S. McKenzie  David E. Kohlwey 《Cereal Chemistry》1999,76(1):56-62

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Life cycle assessment of greenhouse gas emissions from beef production in western Canada: A case study   总被引：2，自引：0，他引：2  

Karen A. Beauchemin  H. Henry Janzen  Shannan M. Little  Tim A. McAllister  Sean M. McGinn 《Agricultural Systems》2010,103(6):371-379

A life cycle assessment (LCA) was conducted to estimate whole-farm greenhouse gas (GHG) emissions from beef production in western Canada. The aim was to determine the relative contributions of the cow-calf and feedlot components to these emissions, and to examine the proportion of whole-farm emissions attributable to enteric methane (CH₄). The simulated farm consisted of a beef production operation comprised of 120 cows, four bulls, and their progeny, with the progeny fattened in a feedlot. The farm also included cropland and native prairie pasture for grazing to supply the feed for the animals. The LCA was conducted over 8 years to fully account for the lifetime GHG emissions from the cows, bulls and progeny, as well as the beef marketed from cull cows, cull bulls, and progeny raised for market. The emissions were estimated using Holos, a whole-farm model developed by Agriculture and Agri-Food Canada. Holos is an empirical model, with a yearly time-step, based on the Intergovernmental Panel on Climate Change methodology, modified for Canadian conditions and farm scale. The model considers all significant CH₄, N₂O, and CO₂ emissions and removals on the farm, as well as emissions from manufacture of inputs (fertilizer, herbicides) and off-farm emissions of N₂O derived from nitrogen applied on the farm. The LCA estimated the GHG intensity of beef production in this system at 22 kg CO₂ equivalent (kg carcass)⁻¹. Enteric CH₄ was the largest contributing source of GHG accounting for 63% of total emissions. Nitrous oxide from soil and manure accounted for a further 27% of the total emissions, while CH₄ emissions from manure and CO₂ energy emissions were minor contributors. Within the beef production cycle, the cow-calf system accounted for about 80% of total GHG emissions and the feedlot system for only 20%. About 84% of enteric CH₄ was from the cow-calf herd, mostly from mature cows. It follows that mitigation practices to reduce GHG emissions from beef production should focus on reducing enteric CH₄ production from mature beef cows. However, mitigation approaches must also recognize that the cow-calf production system also has many ancillary environmental benefits, allowing use of grazing and forage lands that can preserve soil carbon reserves and provide other ecosystems services.  相似文献   

Feline epilepsy     

Karen L. Kline 《Clinical Techniques in Small Animal Practice》1998,13(3):152-158

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Gulf of Maine cod in 1861: historical analysis of fishery logbooks,with ecosystem implications     

Karen E. Alexander  William B. Leavenworth  Jamie Cournane  Andrew B. Cooper  Stefan Claesson  Stephen Brennan  Gwynna Smith  Lesley Rains  Katherine Magness  Reneé Dunn  Tristan K. Law  Robert Gee  W. Jeffrey Bolster  Andrew A. Rosenberg 《Fish and Fisheries》2009,10(4):428-449

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The historical use of fire as a land management tool in New Zealand and the challenges for its continued use     

Baillie  Brenda R.  Bayne  Karen M. 《Landscape Ecology》2019,34(10):2229-2244

Landscape Ecology - New Zealand’s use of fire as a land management tool has had an extensive and lasting impact on New Zealand’s rural landscapes. We reviewed the historical rural use...  相似文献   

Prediction of poppy thebaine alkaloid concentration using UAS remote sensing     

Iqbal  Faheem  Lucieer  Arko  Barry  Karen 《Precision Agriculture》2020,21(5):1045-1056

Precision Agriculture - Alkaloid concentration, which represents the quality of industrial poppy, needs to be estimated in a spatially explicit manner to predict the value of crop prior to...  相似文献   

甘蔗(Saccharum)与斑茅(Erianthus arundinaceus)远缘杂交利用研究   总被引：3，自引：1，他引：3  

王丽萍  蔡青  范源洪  陆鑫  Karen Aiken  马丽  刘新龙  夏红明 《西南农业学报》2007,20(4)

报道了甘蔗与斑茅远缘杂交利用研究结果。本研究利用斑茅及其F1、BC1与甘蔗热带种、栽培种杂交和回交获得了一些斑茅的F1、BC1、BC2真实杂交种。结果表明:斑茅的F1、BC1的结实率低,育性低甚至不育,但通过回交可以提高斑茅杂种的结实率,且回交得到的BC1、BC2表现出了生势强,产量高、锤度高的优势,为选育具有斑茅血缘的高产高糖种质奠定了良好的基础。  相似文献   

Natal origin of the invasive biosecurity pest,brown marmorated stink bug (Halyomorpha halys: Penatomidae), determined by dual‐element stable isotope‐ratio mass spectrometry     

Peter W Holder  Robert J Van Hale  Russell Frew  Sherly George  Karen F Armstrong 《Pest management science》2020,76(4):1456-1463

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