Short-term mesofauna responses to soil additions of corn stover biochar and the role of microbial biomass

Biochar additions have been suggested to influence soil microbial communities that, through a cascade effect, may also impact soil fauna. In turn, any direct biochar effects on fauna can influence microbial communities through grazing, physical fragmentation of organic debris (and biochar) and modifying soil structure. If biochar creates a favorable environment for soil microorganisms, it is also plausible for fauna to be attracted to such microbially enriched habitats. However, how soil fauna respond to biochar addition to soil and what are the main factors that drive their behavior has rarely been experimentally addressed. Therefore, the behavior of two mesofauna species was assessed as a result of corn stover biochar (slow pyrolysis at 600 °C) additions to a loamy temperate soil, after preincubation for 2, 17, 31 and 61 d, and related to variations in microbial biomass and activity. Microbial biomass increased by 5–56% and activity by 6–156% with increasing biochar rates for the different preincubation times. Over the incubation time, microbial biomass did not change or increased at most 15% with the different biochar rates, while in turn microbial activity decreased steadily (around 70–80% at day 61). Enchytraeids generally did not show avoidance or preference to biochar when provided with an alternative unamended soil, while collembolans often showed avoidance responses. However, collembolan avoidance to biochar decreased or disappeared in biochar mixtures with higher microbial biomass and water extractable NH₄-N content, agreeing with the plausible role of microorganisms to potentially attract soil fauna after biochar applications. Avoidance response was mainly explained by environmental preferences of the test species and not by any toxic effect of the biochar in this study. However, avoidance after the application of biochar may still need to be considered due to the potential negative impacts of individuals’ migration on soil ecosystem functioning.     

喜马拉雅狼蛛的生物学生态学特性

运用田间观察与室内外饲养相结合的方法,对西藏林芝地区青稞地蜘蛛优势种喜马拉雅狼蛛Lycose himalayaensis Gravely的生物学生态学特性进行了研究。详细记载了喜马拉雅狼蛛求偶与交配行为过程、产卵与护卵习性、孵化及携幼行为、幼蛛生长、蜕皮、各龄期形态特征、亚成蛛及性成熟。喜马拉雅狼蛛在西藏林芝地区1a发生2~3代,第3代不完整,以第2代历期最短,第3代(越冬代)历期最长;以成蛛或幼蛛越冬;5月中旬即由田边草丛向青稞地内迁移,在青稞作物全生育期间出现2次卵高峰、2次种群密度高峰;在室内发现4龄后的幼蛛在袋状网内蜕皮、交配期和携卵期有结袋状网或幕状网的习性;属游猎型蜘蛛,性凶猛,常游猎在植株、陆地、草地等处捕食飞虱、叶蝉、蚜虫等多种青稞害虫以及其他小型昆虫,其捕食量与龄期、蜕皮和性别有关。雌雄蛛均可多次交配,雌蛛一生可产卵3~5次,卵囊含卵量20~60粒,平均40粒。平均孵化率89.8%。孵化的幼蛛,先群集在雌蛛的背部,4~7d后离开雌蛛分散捕食。幼蛛一般蜕皮6~7次,出卵囊前至少蜕皮1次。喜马拉雅狼蛛的产卵前期3~7d,平均5d;卵期11~17d,平均14d;幼蛛期65~142d,平均98.6d;成蛛期112~168d,平均115d左右,雌蛛较雄蛛长20~45d,平均34.6d。性比除第1代外的各代均为雌多于雄蛛。幼蛛出卵囊后至性成熟的成活率为18.4%~51.3%,平均达31.8%。室内饲养发现在一定湿度条件下,不提供食物成蛛可存活23~52d,平均36.5d。     

克氏原螯虾与中华绒螯蟹混养条件下的行为观察

[目的]对克氏原螯虾与中华绒螯蟹混养条件下的行为进行观察和研究。[方法]在相对狭小空间进行等重量级的虾蟹混养试验,观察记录两者相遇初期的格斗行为及混养后期的胜负结局;在相对宽敞空间——"Y"型迷宫内,观察记录克氏原螯虾对较高重量级中华绒螯蟹的趋避行为。[结果]混养试验中虾蟹相遇初期,螯虾首次攻击及靠近的次数、累计主动靠近次数均极显著大于蟹(P<0.01),累计主动攻击次数显著多于蟹(P<0.05);混养30 d后,虾死蟹存组占30%,蟹死虾存组占10%,共存组占60%。在每只受试虾对较高重量级蟹趋避行为试验中,随着试验次数的增多,螯虾对蟹与空白的选择次数和时间由差异性不显著(P>0.05)变为显著偏向选择空白(P<0.05),即螯虾对蟹的识别能力显著提高了,同时试验螯虾的选择行为受到明显抑制。[结论]可以推测,若提供适合的生境条件,虾蟹混养理论上可获得较好效益。     

基层农业技术推广人员推广行为的影响因素分析

以浙江省从事水稻种植技术推广的基层农技员为研究对象,通过农技员农技服务真正受体——农户的调查,更为客观地了解基层农技员的推广行为,并采用限制因变量Tobit模型深入分析了推广行为的影响因素。研究表明,农技员的年龄、职称、编制3个变量对农技员入户到田指导次数有显著正向影响;推广组织内部人员管理机制方面,明确规定农技员下乡天数,推广工作有明确计划,制定推广工作考核制度都对基层农技员推广行为有正向的促进作用。     

西安骡马市商业步行街设计中的行为心理初探

结合西安骡马市商业步行街的现状,以行为心理学、建筑学、城市设计等相关学科的理论为指导,对人们在骡马市步行街中行为心理进行了分析,对现代城市商业步行街外部空间人性化设计途径进行了探讨。     

茶尺蠖性召唤行为规律研究

在暗期观察了茶尺蠖雌蛾的性召唤行为,结果表明,茶尺蠖的性召唤行为分为持续性和间歇性两种形式,分别占61.90%和38.09%,持续性召唤时间最长为370 min,平均约为207 min。性召唤状态的雌蛾的百分率变化呈现一个明显的高峰期。雌蛾羽化的天数对性召唤状态的雌蛾百分率也有一定影响。     

笼养丹顶鹤繁殖行为和粪样中性激素水平变化的关系

2007年3月～2008年2月,在哈尔滨北方森林动物园,选2对健康的成年丹顶鹤,采用目标取样和扫描取样相结合的方法进行了行为观测,同时收取粪便提取激素,利用放射免疫分析法（RIA）测定了笼养丹顶鹤粪样中睾酮、孕酮、雌二醇的浓度。试验结果表明：笼养丹顶鹤繁殖行为呈显著的季节变化,其对鸣、炫耀行为的高发期在3、4月（P〈0．05）,营巢行为在3月极显著高于其他月份（P〈0．01）,丹顶鹤的交尾行为集中出现在3、4月（P〈0．05）;繁殖期雄性丹顶鹤粪便中睾酮平均水平为（259．59±149．70）ng／dl,非繁殖期为（84．81±27．35）ng／dl,二者差异显著,繁殖期雄鹤求偶炫耀、交尾、卧巢等的发生频次与粪便中睾酮呈极显著相关（P〈0．01）,其对鸣、警戒以及营巢都与睾酮变化水平呈显著相关（P〈0．05）。繁殖期雌性丹顶鹤粪便中的孕酮平均浓度为（9．65±7。15）rig／m1,非繁殖期为（2．76±0．97）ng／ml,差异显著,繁殖期雌鹤粪便中的孕酮激素水平与其卧巢行为呈显著性相关（R=0．8848,P〈0．05）;繁殖期雌性丹顶鹤粪便中雌二醇平均浓度为（30．50±61．77）pg／ml,非繁殖期为（8．17±3．72）pg／ml,二者差异显著,繁殖期雌鸟雌二醇变化水平与其繁殖行为的相关性不显著（P〉0．05）;雌性丹顶鹤粪样中雌二醇激素的变化水平与其产卵时间有着较为密切的关系。     

The effect of three space allowances on the physiology and behavior of weaned pigs during transportation

Stocking density is an important aspect of transport, which could affect animal health and welfare, especially in pigs simultaneously experiencing weaning stress. The objective of this research was to evaluate the effect of three different space allowances on the physiology and behavior of weaned pigs during transport. A commercial semi-trailer with compartments that provided 0.05, 0.06 and 0.07 m²/pig was used throughout the study. All three space allowances were represented on both the upper and lower decks during each replicate. A constant of 100 pigs were loaded into each experimental compartment. Pigs were then transported for 112.5 ± 6.5 min to the wean-to-finishing site using the same route for each replication. This experiment was replicated 4 times. The experimental unit was the compartment. Prior to and after transport, blood samples were taken from a sub-set of pigs (n = 32 pigs/space allowance) for analysis of physiological and immune measures, and body weights and lesion scores were also recorded. Data loggers were fitted inside the trailer to record temperature, humidity, and wind speed. Cameras were placed in each experimental compartment to record behavior and postures of pigs during transport. The frequencies of standing, lying, sitting, standing-rearing on another pig, lying/huddling on top of another pig, total active and total inactive behaviors were recorded using 1-min scan samples during the entire duration of transport. Inside trailer temperature ranged from − 2.4 to 21.7 °C and inside trailer relative humidity ranged from 28.4 to 89.2% during transport. Cortisol, the neutrophil:lymphocyte (N:L) ratio, blood urea nitrogen, total bilirubin, total protein, albumin, aspartate aminotransferase, and creatine kinase were higher (p < 0.05) in pigs after transport regardless of space allowance. Skin lesions were more severe (p < 0.001) in pigs after transport regardless of space allowance. Pigs spent more (p < 0.001) time active during the first 75 min of transport compared with the last 30 min, regardless of space allowance. Pigs spent less (p < 0.01) time standing on another pig during transport at 0.07 m²/pig compared with pigs transported at 0.06 m²/pig. Higher cortisol concentrations and N:L ratio in weaned pigs after transport suggest that these pigs experienced stress, however space allowance did not appear to influence this response. Space allowances of 0.05, 0.06 or 0.07 m²/pig did not differentially influence pig well-being during a 112-min transport period as measured by changes in physiological measures.