高原鼢鼠扰动对高寒草甸土壤理化特性及植物生物量的影响

为揭示高原鼢鼠(Eospalax baileyi)种群密度对高寒草甸土壤理化性质和植物生物量的影响,本研究选择祁连山东缘高原鼢鼠3个不同种群密度(高、中、低)干扰下高寒草甸样地,分析了土壤理化特性、植物生物量变化及干扰强度和土层间的互作效应。结果发现:随种群密度增多,土壤含水量、容重、有机碳、全氮含量和全磷含量均呈增加趋势,而全钾含量和根冠比降低,土壤碳氮比先减后增,总生物量及地下生物量逐渐降低,地上生物量先增后减;同一干扰强度下,土壤土层深度对其pH值、全氮含量和全磷含量有显著影响(P<0.05),对地下生物量和土壤水分有极显著性影响(P<0.01)。干扰强度和土层的互作对全钾、全磷和水分有显著性影响(P<0.05),对pH值和地下生物量有极显著影响(P<0.01)。可见,高原鼢鼠扰动显著改变了土壤理化性质和植物生物量,并与土层深度有互作效应。

Profits and Costs of the Development of Rural Cooperative Economic Organizations

Through analyzing the economic profits of rural cooperative economic organizations,the following conclusions are obtained.The rural cooperative economic organizations can get the economic profits which are in accordance with the demands of market-oriented economy.The rural cooperative economic organizations can benefit from sharing the knight service provided by the government;from reducing and avoiding various kinds of risks in operation and from applying the agricultural technology and standardization production.Besides,the organizations can share the profits bought along by the standardized production of agricultural production and their members can enjoy the profits bought by socialized service system.In addition,the rural cooperative economic organizations can enjoy the profits produced by the agricultural management integration strategy.What' more,they can increase profits by reducing the transaction costs;enlarging scale and enjoying the brand advantages.The analyses of the costs of the development of rural cooperative economic organizations mainly include the organizing costs,operation costs,restriction costs and cooperation costs.We think that the slow development of rural cooperative economic organizations is caused by their high operation cost and the impediment of external environment.In the end,the countermeasures on strengthening the research on the theory,promotion,education and training of rural economic cooperative organizations and intensifying the supports on the policies of rural economic cooperative organizations are put forward.

祁连山东缘高原鼢鼠对溴敌隆的敏感性与适口性测定实验

目的测定祁连山东缘高原鼢鼠对抗凝血杀鼠剂溴敌隆的敏感性与适口性水平,为野外采用溴敌隆鼠药防制高原鼢鼠提供科学依据。方法于2018年7-8月,在祁连山东缘天祝地区采用捕鼠笼非损伤捕获活的高原鼢鼠,实验室环境下单鼠单笼饲养,采用无选择性摄食试验,连续喂食1、3、5和7 d 0.000 5%的溴敌隆毒饵,记录高原鼢鼠取食和死亡情况,使用SPSS 19.0软件Bliss计算机程序,拟合回归分析,计算半致死喂食期(LFP50),99%致死喂食期(LFP99)。采用成组设计资料的t检验,分析其敏感性与适口性。结果高原鼢鼠毒饵取食量有下降趋势,不同性别高原鼢鼠对溴敌隆的敏感性差异无统计学意义(t=-1.232,P=0.329),其LFP50和LFP99的估计值分别为0.492和11.897 d;高原鼢鼠取食毒饵后,死亡高峰期出现在第6~9天。0.000 5%溴敌隆对高原鼢鼠的首遇适口性为0.66,再遇适口性为0.77,均达到良好摄食系数,实验室校正灭鼠率均达100%。结论溴敌隆对祁连山东缘天祝地区高原鼢鼠的毒效高、适口性好,且无抗性发生,0.000 5%溴敌隆可有效防治该地区的高原鼢鼠。