The urbanization of wildlife management: Social science, conflict, and decision making

Increasing urbanization of rural landscapes has created new challenges for wildlife management. In addition to changes in the physical landscape, urbanization has also produced changes in the socio-cultural landscape. The greater distancing from direct interaction with wildlife in urbanized societies has led to the emergence of a culture whose meanings for wildlife are less grounded in the utilitarian/instrumental orientation of rural agrarian systems. Urban perspectives on wildlife are comprised of more highly individualized emotional/symbolic values. This shift creates two problems with respect to managing wildlife in an urbanizing landscape. First the increased diversity in values and meanings increases the likelihood for social conflicts regarding wildlife management while at the same time making socially acceptable resolutions more intractable. This in turn requires fundamental changes in decision-making paradigms and the research approaches used to inform decision making. Second, as remaining rural communities feel the pressures of urbanization, wildlife conflicts become conflicts not just over wildlife but conflict over larger socio-political concepts such as equity, tradition, private property rights, government control, power, and acceptable forms of knowledge. This paper examines the wildlife management implications of changes associated with increasing urbanization and employs two case studies to illustrate these issues. First a study of a controversy over urban deer management provides insights into how to map conflicting values and search for common ground in an urban culture with increasingly individualistic values for wildlife. Specifically, the analysis illustrates that common ground may, at times, be found even among people with conflicting value systems. The second case study examined a ranching community faced with predator reintroduction. This case study illustrates tensions that occur when the community of interest (i.e. a national public) is broader than the community of place in which the problem occurs. In this latter situation, the debate centers around more than just different views about the rights of animals. It also entailed the rights of individuals and communities to decide their future. The conclusion discusses the need for wildlife institutions to adapt their underlying decision making philosophy including the way science is integrated into decision making processes in light of the changes in social context caused by urbanization.     

Effects of weed control practices on surface-dwelling arthropod predators in tomato agroecosystems

Weed control, an important practice in agroecosystems to protect crop production, is usually achieved with herbicides. However, these pesticides are expensive, pose potential risks to the environment, may affect some beneficial organisms indirectly, and decrease overall arthropod biodiversity, including pests and their natural enemies, by removing weeds that might act as hosts or shelters for many organisms. The activity density response of important surface-dwelling arthropod predators (ground beetles [Coleoptera: Carabidae], ants [Hymenoptera: Formicidae] and spiders [Arachnida: Araneae]) to herbicides (trifluralin and paraquat), and to two alternative weed management practices (rye straw mulch and mechanical treatment to maintain weeds below threshold levels, in comparison with an untreated check), was assessed using pitfall traps. The mulch treatment had the greatest effect on activity density, reducing the number of predators trapped significantly (P<0.05). Herbicide use resulted in significant (P<0.05) reductions in the activity density of ground beetles. Most predators were trapped in the check plots — which had the highest weed biomass, followed in turn by numbers trapped in the threshold weed control treatment, the full herbicide application and the mulch treatment plots. http://www.phytoparasitica.org posting July 10, 2002.     

草原生态环境发展与创新——由“补助奖励”到“精确放牧”

为增进草原生态保护政策的有效性,本研究考察了国内草原"补助奖励"政策的实施效果与存在问题。具体以268个牧区半牧区县牧业人口、牲畜超载率和农牧民纯收入变化情况为研究对象,运用比较分析对比"补助奖励"政策前后全国草畜平衡状况,并结合BGLI模型计算"补助奖励"政策的实施对草原超载问题的改善情况。结果表明"补助奖励"政策对全国的超载现状有很好的改善作用,增加了牧区半牧区县的人口和牧民纯收入,尤其对半牧区县的正面影响更加突出,牧区半牧区县整体对该政策的满意度很高。但无差别化的补助标准在一定程度上造成了"补助奖励"政策实施效率的低下,预期效果并不理想。因而本研究认为,应通过建立数据库的办法实施"精确放牧"政策,并提出先减后补,根据超载程度做好多补,中小牧户为补贴主体等建议。     

捕虱管蓟马生物学的初步研究

捕虱管蓟马是柑桔盾蚧卵和幼蚧的重要捕食性天敌。在广州地区各虫态均可越冬。该虫常在隐蔽场所活动和取食。种群数量在5月上旬有一显著的高峰(22.1头/叶),此后虫口数量就逐渐下降。在室内(平均气温22～27℃)条件下,完成一个世代需35.4天,产卵量为22.2±6.5粒。雌雄性比平均为3:1。成虫寿命雌17.4±5.6天,雄7.4±4.2天。雌成虫在室内平均一天能捕食褐圆蚧雌虫3.3头,或糠片蚧8.4头。当食料缺乏时,有自相残杀的习性。     

应用赤眼蜂蛹人工饲养尼氏钝绥螨的研究初报

本文首次报导应用赤眼蜂蛹作为替代食料人工饲养尼氏钝绥螨。日食蛹量,幼螨为0.18头,产卵前期成螨达1.18头,而产卵期成螨则为0.95头左右。在25℃饲养条件下,每雌产卵达45粒,卵历期48小时,孵化率近92％,幼螨存活率88％,成螨雌性占55％,雌成螨寿命25天。用赤眼蜂蛹连代饲养的尼氏钝绥螨在桔园释放,对柑桔全爪螨具有明显的控制作用。     

氮肥对水稻叶冠层捕食性天敌种群及其自然控制能力的影响

为了公正地评价氮肥对整个稻田生态系统的影响，在国际水稻研究所试验场分别设立0、100和200kg／hm^2三个氮肥水平，测定了水稻主要特性参数和叶冠层捕食性天敌的种群动态，同时以果蝇蛹作为替代猎物的方法在田间模拟评价了叶冠层捕食性天敌对害虫的自然控制能力。结果表明，虽然施用200kg／hm^2氮肥稻田的稻株高度、叶面积和稻草干重显著比施用100kg／hm^2氮肥稻田的高，但每丛分蘖数和稻谷产量则没有明显差异。在水稻叶冠层中，肖蛸、圆蛛、黑肩绿盲蝽、稻红瓢虫和捕食性螅等为稻飞虱主要捕食性天敌。肖蛸在水稻孕穗期的数量最高，圆蛛的种群随水稻的生长而下降，但黑肩绿盲蝽、稻红瓢虫和捕食性螅的数量却均随水稻的生长而增加。施用氮肥后稻田中肖蛸和稻红瓢虫的种群数量显著减少。在水稻孕穗期，叶冠层上蜘蛛网的数量和蜘蛛网总面积均随氮肥施用量的提高而显著减少。在水稻孕穗期和乳熟期，不施用氮肥稻田中的捕食性天敌对替代猎物果蝇蛹的捕食能力显著高于其它两个施用氮肥的稻田中的捕食能力。而在乳熟期施用100kg／hm^2氮肥稻田的捕食能力又显著比施用200kg／hm^2氮肥稻田的高。结果说明过量施用氮肥可削弱天敌对害虫的自然控制作用。     

Antipredator behaviour of naïve Arctic charr young in the presence of predator odours and conspecific alarm cues

Abstract –  We investigated how Arctic charr young respond behaviourally to olfactory cues from skin-damaged conspecifics, charr-fed pikeperch, and the combination of food-deprived pikeperch and skin-damaged conspecific cues in a two-channel Y-maze fluviarium test arena. Significant antipredator responses were found to skin-damaged conspecifics in three behavioural traits, to charr-fed pikeperch in two traits and to the combination of pikeperch and skin-damaged conspecific cues in all six behaviours investigated. The combination of predator and conspecific cues significantly increased spatial avoidance and cautiousness to approach the source of scent compared with odours from charr-fed predators. The results suggest that damage-released alarm cues exist in charr, and they strengthen the antipredator responses in conspecifics. As the charr used different behaviours and levels of response in the presence of different cues, they seem to have sophisticated skills to distinguish between different odour combinations and be able to adjust their behaviour according to the current predation risk level.     

粮食购销改革的问题与对策

粮食购销体制改革被称为“跨世纪难题”。它曲曲折折,走走停停,踟蹰了18年。2003年粮改终于发生了一个飞跃,安徽省等地进行的粮食直补改革试点,实现了粮食购销的市场化。虽然这项改革尚存在有待于解决的问题,但不失为一项利国利民的高明之举。     

东港市水稻插秧机推广经验探讨

针对机插秧发展速度较慢的实际,东港市抓住国家实施农机购置补贴政策的机遇,把水稻机插秧列为水稻全程机械化的重点工作,采取政府主导、补贴拉动、基地示范、宣传推广、技术培训、目标考核等举措,推动全市水稻全程机械化发展,为各地水稻机插秧技术的推广提供了经验。同时,对机插秧技术推广过程中存在的一些问题进行了剖析,以便为下一步解决问题提供依据。     

Larger body size with higher predation rate

Abstract –  Many studies have reported that prey fish increase in body size with an increase in piscivore abundance, and this change may be explained mainly by two processes: release from intraspecific competition because of a reduction in the prey fish population and size-dependent selection by the piscivore. However, the evolutionary mechanism is not yet fully understood. Here, we first show the body-size dynamics of the semelparous gobiid fish Gymnogobius isaza , which is one of the prey fishes of the introduced largemouth bass, Micropterus salmoides . The data show the possibility that the goby body size might have changed in parallel to the number of largemouth bass from 1975 to 2002, which may be one of the best examples of the positive relationship between body size and predation rate. Furthermore, we explored a mathematical model to consider a body-size change of semelparous fish from an evolutionary viewpoint. The model provided the following qualitative predictions: (1) the optimal assimilation rate increases with predation pressure; (2) a rapid large-scale increase in predation pressure may exterminate the prey fish because of delayed evolution of the assimilation rate; and (3) the optimal assimilation rate increases when the prey fish is more likely to die through predation than through natural mortality or when it is difficult to grow larger because of low resource availability or insufficient foraging efficiency. Moreover, we propose a theoretical framework to evaluate the relative effects of ecological and evolutionary processes over the long term.