Analysis of regional variation of height growth and slenderness in populations of six urban tree species using a quantile regression approach

Inventory data of six urban tree species from seven cities across Germany were used to model regional variation of height growth, allometric scaling, and slenderness over a wide range of size and age using a quantile regression approach. Variation within and between species and cities was large. Height did not reach an asymptote but declined at higher ages, presumably because of reduction cuts. Allometric scaling and slenderness varied with wind climate, modulus of elasticity, and coefficient of drag. Our data do not support the use of a threshold value of slenderness in tree risk assessment.     

甘肃天祝牧区白牦牛乳脂肪中脂肪酸的分析

以甘肃天祝地区3个牧场所产的白牦牛乳为研究对象,采用气相色谱-质谱联用检测方法,测定3个牧场所产白牦牛乳中脂肪酸含量,比较在枯草期、枯草末期、返青期、青草期4个时期及不同胎次的白牦牛所产牦牛乳中脂肪酸的构成及含量.结果表明:3个牧场白牦牛乳中乳脂肪酸含量差异不显著(P＞0.05);1～5胎次母白牦牛乳中脂肪酸含量差异不显著(P＞0.05).枯草期、枯草末期、返青期、青草期4个时期白牦牛乳中饱和脂肪酸(SFA)、不饱和脂肪酸(USFA)含量比值分别为1.86、1.75、1.62、1.32.随着气温的升高及牧草的成熟,白牦牛乳中饱和脂肪酸含量逐渐降低,而不饱和脂肪酸的含量逐渐升高.     

Dominance in domestic dogs revisited: Useful habit and useful construct?

In the last decade, the validity and relevance of the dominance model was regularly put into question regarding relationships between canids like dogs and wolves, and consequently, human–dog relationships as well. The concept underlying this model, scientifically defined as an intervening variable reflecting status difference between individuals, is applicable when formal status signals symbolize the long-term relationship between individuals, resulting in a formalized dominance hierarchy. This article reviews the basics underlying the concept of dominance and reflects on the value and importance of some new quantitative studies on the applicability of the concept of dominance in domestic dogs. The conclusions are, first, that formal dominance is present in the domestic dog, expressed by context-independent unidirectional formal status signals. Consequently, formal dominance (e.g., submission) plays an important role in assessing status in dog–dog relationships. Second, that nonverbal status–related communication in humans resembles that in dogs to a considerable degree, and hence dogs may be well able to interpret this human status–related nonverbal communication from their perspective. Dominance is therefore also likely to play a role in human–dog relationships. Hence, the dominance concept might be useful to explain the development of certain problems in dog–dog and dog–human relationships. However, enforcing a dominant status by a human may entail considerable risks and should therefore be avoided.     

Rodent abundance triggered switch between the relative mutualism and predation in a rodent–seed system of the subtropical island forest

Density-dependent non-monotonic species interactions are important in maintaining ecosystem stability and function, but empirical evidences are still rare. Rodents, as both seed dispersers and seed predators, have dual effects on plant regeneration and may result in non-monotonic rodent-plant interactions. According to the non-monotonic models, the relative positive or negative effects of rodents on seedling establishment can be measured based on the positive or negative association of seedling recruitment rate and rodent abundance. In this study, we investigated the fates of acorns of Quercus serrata by tracking tagged seeds on 21 fragmented subtropical islands in the Thousand Island Lake, China. We found that the proportion of germinated seeds of all released seeds showed a dome-shaped association with rodent abundance per seed. The proportion of removed seeds and cached seeds showed a saturated- and a weak dome-shaped association with rodent abundance per seed, respectively. Our results demonstrated a clear empirical evidence that rodent abundance per seed triggered a switch between the relative mutualism and predation in a rodent–seed system. Our study implied that the observed non-monotonic interactions between plants and animals may play a significant role in maintaining biodiversity and ecosystem function. We appeal for more investigations of the complex non-monotonic interactions in various ecosystems.     

Stewardship as a Path to Cooperation? Exploring the Role of Identity in Intergroup Conflict Among Michigan Wolf Stakeholders

Post-recovery wolf management remains controversial. In Michigan, dialogue centers on hunting wolves but controversy may be more nuanced than simple pro- or anti-hunting positions. Social identity may cause stakeholders to organize in groups and identity differences may be driving controversy. To explore stakeholder disagreement over wolf management, we conducted semi-structured key informant interviews (n = 21) about identity and stewardship in August–September 2012. Four overarching identity themes emerged regarding: (a) management objectives, (b) focal levels, (c) control methods, and (d) justifications for methods. Themes indicated two main researcher-defined identity groups. Interviewees from both groups identified six common stewardship themes: (a) bequest values, (b) ecosystem health, (c) education, (d) existence values, (e) pride in natural resources, and (f) sustainability. Findings suggest stakeholders may be conflicting over opposing identities vis-à-vis organization affiliation, which may be related to what management strategies individuals oppose. Establishing common stewardship objectives through established participation methods may help alleviate controversy.     

青南牧区雪灾危害的防御

为防灾减灾,利用调查研究,分析了降雪量、低温、牲畜膘情、草地产草量、饲草储备、保温、草地载畜量、雪灾预报、抗灾组织等因子,对青南牧区雪灾危害的影响,提出通过人为干预防御雪灾的综合措施,并制定了入冬前进行的抗灾能力评定标准。     

Hyaluronidase administered with xylazine–tiletamine–zolazepam into adipose tissue shortens recovery from anesthesia in pigs

Objective

To evaluate the effect of hyaluronidase on uptake, duration and speed of elimination of xylazine–tiletamine–zolazepam administered in the subcutaneous fat over the dorsal lumbar region of swine.

积雪覆盖下土壤热状况及其对气象因素的响应研究

为研究季节性冻土区在积雪覆盖条件下,土壤温度变化趋势及气象因素对土壤热状况的影响,以野外实测试验数据(2013年11月8日—2014年4月28日)为基础,分析裸地、自然降雪、积雪压实和积雪加厚覆盖条件下5、10、20、40、60、100、140 cm深度土壤温度变化特征,采用灰色关联度分析的方法筛选出影响土壤热状况的主要气象因素,进而统计土壤温度与气象因素之间的相关关系。结果表明:积雪的存在阻碍了环境与土壤之间的能量交换,引起土壤温度和土壤冻融过程的差异;随着积雪覆盖深度的增加,土壤的冻融日期会出现延迟现象,土壤温度相对稳定在较高水平,并且地、气之间温差增大;冻融过程中土壤温度变化的主要影响因素为环境温度,积雪覆盖使得气象因素与土壤温度的关联度减弱。     

Improving soil organic carbon pools through inclusion of summer mungbean in cereal-cereal cropping systems in Indo-Gangetic plain

Long-term effect of mungbean inclusion in lowland rice-wheat and upland maize-wheat systems on soil carbon (C) pools, particulate organic C (POC), and C-stabilization was envisaged in organic, inorganic and without nutrient management practices. In both lowland and upland systems, mungbean inclusion increased very-labile C (Cfrac₁) and labile C (Cfrac₂) in surface soil (0–0.2 m). Mungbean inclusion in cereal-cereal cropping systems improved POC, being higher in lowland (107.4%). Lowland rice-based system had higher passive C-pool (11.1 Mg C ha^?1) over upland maize-based system (6.6 Mg C ha^?1) indicating that rice ecology facilitates the stabilization of passive C-pool, which has longer persistence in soil. Organic nutrient management (farmyard manure + full crop residue + biofertilizers) increased Cfrac₁ and carbon management index (CMI) over inorganic treatment. In surface soil, higher CMI values were evident in mungbean included cropping systems in both lowland and upland conditions. Mungbean inclusion increased grain yield of cereal crops, and yield improvement followed the order of maize (23.7–31.3%) > rice (16.9–27.0%) > wheat (lowland 7.0–10.7%; upland 5.4–16.6%). Thus, the inclusion of summer mungbean in cereal-cereal cropping systems could be a long-term strategy to enrich soil organic C and to ensure sustainability of cereal-cereal cropping systems.