草地灾害对草地畜牧业发展的影响分析--以西藏那曲地区为例

介绍了雪灾、风害、干旱、鼠虫草害、草地退化、沙化和水土流失等六类主要的草地灾害类型,并分析了其对草地畜牧业发展造成的影响.结果表明：草地灾害给草地畜牧业发展带来极大的负面效应,具体表现在对草地生态与环境的破坏;加剧草地承载压力;制约草地畜牧业的可持续发展等三个方面.     

四环素类抗生素污染畜禽粪便的厌氧消化特征

应用间歇试验研究了外源添加四环素(TC)和金霉素(CTC)的猪粪中温(35℃)厌氧消化特征及抗生素的降解过程.结果表明,猪粪厌氧水解酸化过程中产生的挥发性脂肪酸以丙酸为主,乙酸次之;相比于CTC添加组,TC+CTC混合添加组对易降解有机物的水解酸化有明显的抑制作用;添加TC、CTC和TC+CTC组在45 d的消化期内累积产甲烷量分别为386.4、406.0和412.1 mL,与不添加TC和CTC的对照组(464.6 mL)相比,分别减少了16.8%、12.6%、11.3%.四环素和金霉素的降解过程符合一级反应动力学方程;四环素降解的半衰期为14～18 d,金霉素为10 d.经过45 d厌氧消化处理后,四环素的降解率达88.6%～91.6%,金霉素达97.7%～98.2%.因此,畜禽粪便厌氧消化处理不仅能回收生物质能源,还能降解残留的四环素类抗生素,有效地降低抗生素污染产生的生态风险.     

基于草地畜牧业生产的三江源地区承载力多情景模拟分析

三江源地区是我国生态安全的重要屏障,同时也是我国最主要的畜牧业生产基地之一,在保证草地资源可持续利用前提下,探究合理的人口容量对该区的生态保护建设和可持续发展具有重要意义。通过模型模拟草地理论载畜量以估算畜牧业产值,设定三种居民生活水平情景,模拟不同情景不同时期下的适度人口容量,分析人口承载力的空间差异性。结果表明：“十五”期间,三种情景下全区人口承载力呈富余状态;“十一五”和“十二五”期间在当前居民和小康水平情景的人口容量尚有结余;到“十三五”期间,三种情景下人口承载力总体均超载,但空间分布不同,在当前居民、小康和富裕生活水平情景下,分别有11个、8个和2个县的人口容量尚有结余,人口承载力超载地区主要分布于三江源地区东部。应根据现有资源分布和符合主体功能要求的方向进行调整和优化人口结构,将对该地区可持续发展战略具有重要意义。     

基于虹膜识别的肉类食品可追溯系统研究

为了加强食品安全管理,提高肉类食品溯源准确性的目的,首先提出肉类食品溯源体系的3个基本要素,认为:动物个体识别是肉食品质量控制的重要环节;采用虹膜识别作为大型动物个体识别的关键技术;解决了其他动物识别系统中的欺骗以及设备功能异常现象等问题。以奶牛为例,讨论人眼虹膜识别技术应用于大型动物识别在图像采集、虹膜定位、特征提取3方面存在的技术难点;给出了实现动物虹膜识别的技术路线;最后构建了基于虹膜识别的肉食品可追溯系统。通过详细功能划分和流程设计,为虹膜技术在肉食品可追溯系统中的应用实施提供了参考。     

计及降雨量的养殖场沼气热电联供系统建模与经济分析

针对夏季强降雨导致厌氧发酵沼气产量理论值偏离实际值的问题,构建计及降雨量的奶牛养殖场沼气热电联供系统仿真模型;然后利用仿真模型计算分析不考虑降雨时与考虑降雨时系统日净收益的偏差;最后探讨1月份发电机组与沼气锅炉的沼气合理分配问题以提高经济效益。首先基于实际现场能量流动关系,建立了厌氧发酵罐、沼气净化装置、储气罐、内燃机发电机组、缸套水换热器、沼气锅炉、蓄热水箱的数学模型。其次,考虑强降雨对料液浓度与料液密度的影响,建立降雨量模型,使雨季日沼气产量模拟值与实际值更吻合。然后在系统仿真模型基础上建立日净收益模型,分别模拟计算不考虑降雨与考虑降雨时的系统日净收益并与实际日净收益对比分析;最后利用日净收益模型求出不同日进料量条件下发电机组不同沼气用量所对应的日净收益,以确定各种进料量条件下的发电机组最佳沼气用量。利用养殖场2020年全年实际运行数据对沼气热电联供系统仿真模型进行正确性验证,建立降雨量模型后日沼气产量模拟值与实际值之间的线性回归决定系数由0.66提升至0.73;日发电量模拟值与实际值之间的线性回归决定系数为0.7;考虑降雨量后日净收益模拟值比不考虑降雨量的日净收益模拟值在准确性上有了很大提高。该研究结果表明,该模型对于该养殖场沼气热电联供系统的工艺流程模拟分析具有准确性和有效性,可为实施养殖场沼气热电联供系统的优化调度、控制规划等提供参考。     

Reducing ammonia gas from chicken manure with lime and soybean plants

This research is aimed at addressing the complaints of local people living near chicken farms who are disturbed by odors caused by livestock activities, and specifically, by the generation of ammonia gas from chicken manure. Methods that are expected to reduce the intensity of ammonia gas odors include both scattering lime on the surface of the soil and planting soybeans around the cages. The results obtained showed a reduction in the levels of ammonia gas by 57.48%–from 1.67 parts per million (ppm) near an untreated cage to 0.71 ppm near the cage that achieved the best results. The study found that spreading lime evenly over the chicken manure was the most effective method that farmers could use to reduce ammonia odors. The sample area treated by the addition of soybean plants showed a reduction in the levels of ammonia gas from 1.67 to 0.78 ppm.     

Public receptiveness to policies promoting plant-based diets: framing effects and social psychological and structural influences

Governmental and non-governmental organizations, social movements, and academics have called for reductions in meat consumption due to the environmental, animal welfare, and public health consequences of industrial animal agribusiness. An impactful move toward plant-based diets would require changes in public policy. First, we assess if there are different social and structural factors that influence support for policies that promote plant-based diets. We look at four categories of policies (action frames) that will likely reduce meat consumption: environmental, animal welfare, public health, and direct meat reduction. Second, we use a manipulation rhetorical frame to see if support can be altered by providing individuals with information about meat reduction, framing the issue in terms of environmental protection, animal welfare, or public health. Different social and structural factors predict support for different policy groupings, meaning that it matters how policies are enclosed in action frames. However, providing information to individuals about a particular impact (rhetorical frame) has limited influence on policy support.     

Effects of development of wind energy and associated changes in land use on bird densities in upland areas

Wind energy development is the most recent of many pressures on upland bird communities and their habitats. Studies of birds in relation to wind energy development have focused on effects of direct mortality, but the importance of indirect effects (e.g., displacement, habitat loss) on avian community diversity and stability is increasingly being recognized. We used a control-impact study in combination with a gradient design to assess the effects of wind farms on upland bird densities and on bird species grouped by habitat association (forest and open-habitat species). We conducted 506 point count surveys at 12 wind-farm and 12 control sites in Ireland during 2 breeding seasons (2012 and 2013). Total bird densities were lower at wind farms than at control sites, and the greatest differences occurred close to turbines. Densities of forest species were significantly lower within 100 m of turbines than at greater distances, and this difference was mediated by habitat modifications associated with wind-farm development. In particular, reductions in forest cover adjacent to turbines was linked to the observed decrease in densities of forest species. Open-habitat species’ densities were lower at wind farms but were not related to distance from turbines and were negatively related to size of the wind farm. This suggests that, for these species, wind-farm effects may occur at a landscape scale. Our findings indicate that the scale and intensity of the displacement effects of wind farms on upland birds depends on bird species’ habitat associations and that the observed effects are mediated by changes in land use associated with wind-farm construction. This highlights the importance of construction effects and siting of turbines, tracks, and other infrastructure in understanding the impacts of wind farms on biodiversity.     

Underaddressed animal-welfare issues in conservation

Much progress has been made toward assessing and improving animal welfare in conservation. However, several glaring knowledge gaps remain where animal-welfare concerns exist but animal-welfare studies have not been performed in politically sensitive contexts. Based on contemporary issues in Australia, we identified 4 topics that require more research: animal-welfare oversight for operations designated as management (as opposed to research); animal-welfare impacts of biological agents used to control invasive animals; welfare of animals hunted recreationally; and animal-welfare impacts associated with indigenous wildlife use. Animal-welfare science may be applied to these sensitive topics through simple quantitative studies (e.g., quantifying the frequency of adverse animal-welfare events). Several such studies have effectively addressed animal-welfare concerns in similarly contentious contexts, including feral camel (Camelus dromedarius) culling in Australia, recreational hunting in Scandinavia, and indigenous whale hunting in the United States. For discussions of animal welfare in conservation to be evidence-based, courageous research is required in the 4 key areas we identified.     

利用藻类养殖技术处理有机废水与人畜废物

未经处理而排放的有机废水及人畜废物会给环境造成严重污染,同时也造成了大量的资源浪费。利用藻类养殖技术处理这些废弃资源,既改善了环境又可生产出优良的藻类产品,具有巨大的社会与经济效益。本文对该领域的特点、具体应用及其前景作了较为详细的论述。