Benefits and costs of earwig (Forficula auricularia) family life

The evolution of parental care and family group formation critically depends on offspring survival benefits and parental fecundity costs of care under given ecological conditions. Investigations of the functional significance of care in insect species that exhibit facultative parental care have been relatively rare but may be of particular interest for better understanding of benefit and cost schedules at an early evolutionary stage. In this study, aspects of benefits and costs of care were addressed in the sub-social European earwig (Forficula auricularia; Dermaptera: Forficulidae) by manipulating the presence of tending mothers and brood size in a fully crossed experimental design. Larvae growing in broods tended by their mother or of reduced size showed a higher survival probability than larvae growing in untended or large broods, as predicted if maternal care is beneficial and shaped by a trade-off between number and quality of offspring. Analysis of patterns of food consumption and developmental time further suggested that the benefit of maternal attendance is mediated by the maternal provisioning of food, while the quality–quantity trade-off seemed to be driven by sibling rivalry. Further, tending mothers delayed the production of a second clutch, indicating a potential cost of care in terms of lifetime fecundity. This study experimentally shows benefits and potential costs of maternal care and family group formation in the European earwig. More detailed behavioural experiments will be required to fully understand how behavioural interactions among family members mediate these reproductive outcomes.     

基于生态系统服务簇的生态功能区权衡与协同关系演变：以吐哈地区为例

明确生态功能区的空间分布和组成结构,了解多种生态系统之间的权衡与协同关系的演变规律,对吐哈地区生态系统的科学管理和修复至关重要.研究旨在探索各生态系统服务簇的权衡协同关系,并根据生态特征制定差异化的生态管理策略.基于InVEST模型和价值当量法估算吐哈地区2000~2020年6种生态系统服务,即固碳量、产水量、土壤保持、生境质量、粮食生产和美学景观.通过计算多种生态系统服务景观指数（MESLI）量化不同区域的多种生态系统服务综合能力.使用SOFM算法识别生态系统服务簇,确定区域主导服务功能并划分生态功能区.最后,采用Spearman相关分析方法探究全域以及不同服务簇内各生态系统服务之间的权衡协同效应.结果表明：①2000~2020年,吐哈地区建设用地、耕地、水域和林地面积增长,其中建设用地增幅最大,草地和未利用土地的面积持续减少.②产水量、生境质量、土壤保持、美学景观、固碳量和粮食生产呈“北高南低”的空间分布格局,粮食生产高值区主要分布在山前平原绿洲内耕地区域.2000~2020年,固碳量和粮食生产年均值先增后减,美学景观先减后增,产水量逐年上升,土壤保持逐渐下降,2020年生境质量出现轻微下降.③MESLI值多年平均值为0.49,表明地区整体提供各种生态系统服务的能力较弱,生态系统结构的完整性较低.MESLI整体呈“中、西高,南低”的空间格局,具有明显的空间分异性.地区以低MESLI值为主,占总面积的79.46%.④识别出4种生态系统服务簇,分别为生态涵养簇、生态保护簇、粮食生产簇以及生态脆弱簇.生态脆弱簇面积占比最大,生态保护簇最小,具体顺序为：生态脆弱簇>生态涵养簇>粮食生产簇>生态保护簇;生态涵养簇提供多种生态系统服务能力最强,生态脆弱簇最弱.⑤吐哈地区全域尺度下,各生态系统服务间关系以协同为主;由于受区域土地利用类型和自然条件的影响,服务簇尺度下生态系统服务间的关系与全域尺度存在明显差异,且不同服务簇中相同服务组合的权衡/协同关系具有相似性和差异性.研究成果可为吐哈地区可持续发展和生态环境优化提供科学依据.     

Client preferences by Caribbean cleaning gobies: food,safety or something else?

Predation risk is amongst the most pervasive selective pressures influencing behaviour and animals have been repeatedly shown to trade-off foraging success for safety. We examined the nature of this trade-off in cleaning symbioses amongst Caribbean coral reef fishes. We predicted that cleaning gobies (Elacatinus evelynae and Elacatinus prochilos) should prefer fish clients that pose a low risk of predation (e.g. herbivores) over clients that may have more ectoparasites but pose a higher risk (e.g. piscivores). Our field observations revealed that cleaners did clean preferentially client species with more parasites but predatory and non-predatory clients had similar ectoparasite loads. Despite the lack of a foraging advantage for inspecting predators, cleaners did not avoid risky clients. On the contrary, a larger proportion of visiting predators than non-predators was inspected, gobies initiated more interactions with predatory clients, and predators were attended to immediately upon arrival at cleaning stations. This preferential treatment of dangerous clients may allow the rapid identification of cleaners as non-prey item or may be due to the effect of predators on the rest of the cleaners’ clientele, which avoided cleaning stations whilst predators were present. Dealing with potentially risky clients may allow gobies to regain access to their main food source: non-predatory clients.     

土壤水分和氮素水平对春小麦水分与氮素利用效率的影响

以抗旱性不同的三个春小麦品种为材料,研究它们在不同水氮水平下水分利用效率(WUE)和氮素利用效率(NUE)的变化,探讨二者间的相关性。结果表明:三个品种中,和尚头和定西35号的WUE相当,而定西35号的NUE最高。三个春小麦品种叶片NUE均随施氮量增加而降低,整株水平的NUE与氮素水平负相关。施氮量对春小麦叶片光合作用的瞬时WUE影响不显著,整株WUE与施氮量显著正相关。水氮耦合作用对春小麦NUE具有重要影响,整株NUE对水分条件的响应表现出明显的氮水平依赖性。春小麦品种氮素利用和水分利用两个生理过程之间存在\"负偶联\"关系。     

Phenotypic correlates and survival consequences of male mating success in lek-mating greater prairie-chickens (<Emphasis Type="Italic">Tympanuchus cupido</Emphasis>)

Female choice and male–male aggression are two modes of sexual selection that can lead to elaboration of male morphological and behavioral traits. In lek-mating species, male mating success is often strongly skewed, and it is puzzling why variation in male traits is still observed given directional female choice. If male traits correlated with reproductive success are honest signals of male quality, there may be survival costs associated with the expression of those traits. In this study, we examined whether morphological, behavioral, and territorial traits are correlated with male mating success and survival in the lek-mating greater prairie-chicken (Tympanuchus cupido). We introduce a novel application of multinomial discrete choice models for analysis of female mate choice behavior. We found that behavioral and territorial attributes showed 6.5 times more variability among males than morphological traits. Both display and aggressive behaviors were strong predictors of male mating success, suggesting that both female choice and male–male aggression were important in determining mating success among male greater prairie-chickens. Moreover, annual survival of male prairie-chickens was independent of mating success and male traits. Females appear to be choosing males based on behavioral traits where large variation exists between males (coefficient of variation >30%). Behavioral traits were the most important factor in determining mating success of male prairie-chickens, but the mechanism underlying this relationship is unknown. In the future, experimental manipulations of male hormones or parasite loads could bridge the proximate mechanisms and ultimate consequences of factors mediating male mating success in lek-mating grouse.     

Optimizing the operation of the Qingshitan Reservoir in the Lijiang River for multiple human interests and quasi-natural flow maintenance

For reservoir operation, maintaining a quasi-natural flow regime can benefit river ecosystems, but may sacrifice human interests. This study took the Qingshitan Reservoir in the Lijiang River as a case, and developed an optimization model to explore a trade-off solution between social-economic interests and nature flow maintenance on a monthly base. The objective function considered irrigation, cruise navigation and water supply aspects. An index of flow alteration degree was proposed to measure the difference between the regulated discharge and the natural flow. The index was then used as an additional constraint in the model besides the conventional constraints on reservoir safety. During model solving, different criteria were applied to the index, representing various degrees of alteration of the natural flow regime in the river. Through the model, a relationship between social-economic interests and flow alteration degree was established. Finally, a trade-off solution of the reservoir operation was defined that led to a favorable social-economic benefit at an acceptable alteration of the natural flow.     

生态系统服务冲突及权衡的研究进展

生态系统提供了人类生活所需的各种产品,支撑和维护人们赖以生存的生态环境。由于人类对自然生态系统认识不足和使用不当,各种生态系统服务之间出现了冲突矛盾,限制着彼此的发挥,因此,权衡不同生态系统服务之间的关系具有重要意义。文章首先分析了冲突权衡(trade-off)产生的原因、类型差异和研究意义,接下来总结了冲突权衡分析方法进展、应用情况、有待解决的问题和未来重点研究方向。尽管对于生态系统服务的认识,尤其是价值评估已经得到了充分研究,但是生态系统服务的冲突与权衡还处于起步阶段,文章总结了当前生态系统服务权衡的热点问题,包括主要的权衡分析方法以及应用领域,提出展望和建议。未来的研究重点在以下2个方面:第一,深入研究各服务相互关联的作用因子和作用机制;第二,如何综合运用已知条件和方法,构建一个科学合理的权衡模式。     

黄河流域生态系统服务权衡协同关系及其时空异质性

探析生态系统服务之间权衡协同关系及其内在影响机制,对提高生态系统的整体效益,保障生态系统服务的可持续供给至关重要.以黄河流域499个县域为研究对象,在测度黄河流域各县域生态系统服务价值的基础上,采用Pearson相关系数法测度各县域的权衡与协同关系,并构建地理加权逻辑回归（GWLR）模型考察权衡协同与各影响因素之间的时空异质性.结果表明：(1)2001～2021年黄河流域生态系统服务价值先上升再下降最后上升,呈现“下游低、中上游高”的空间分布格局.(2)通过对生态系统服务进行权衡与协同分析,发现研究期内黄河流域各生态系统服务之间的权衡关系存在于食物生产与调节服务和支持服务之间,协同关系存在于调节服务和支持服务内部及其二者之间.(3)通过对潜在因子进行初次筛选和二次筛选,得到建设用地占比变化、年均归一化植被指数（NDVI）变化、年均降水量变化、年均温度变化、人口密度变化和GDP变化6个自变量对6组生态系统服务之间的关系影响较为显著.(4)与其他因子相比,建设用地占比变化和年均温度变化,对生态系统服务权衡协同的时空非平稳响应更强烈.研究结果有利于优化黄河流域生态系统服务效益,为制定精细化的管理措施和政策提供支持.