Comparative phylogeography of mutualists and the effect of the host on the genetic structure of its partners

Whether or not species participating in specialized and obligate interactions display similar and simultaneous demographic variations at the intraspecific level remains an open question in phylogeography. In the present study, we used the mutualistic nursery pollination occurring between the European globeflower Trollius europaeus and its specialized pollinators in the genus Chiastocheta as a case study. Explicitly, we investigated if the phylogeographies of the pollinating flies are significantly different from the expectation under a scenario of plant–insect congruence. Based on a large‐scale sampling, we first used mitochondrial data to infer the phylogeographical histories of each fly species. Then, we defined phylogeographical scenarios of congruence with the plant history, and used maximum likelihood and Bayesian approaches to test for plant–insect phylogeographical congruence for the three Chiastocheta species. We show that the phylogeographical histories of the three fly species differ. Only Chiastocheta lophota and Chiastocheta dentifera display strong spatial genetic structures, which do not appear to be statistically different from those expected under scenarios of phylogeographical congruence with the plant. The results of the present study indicate that the fly species responded in independent and different ways to shared evolutionary forces, displaying varying levels of congruence with the plant genetic structure. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 1021–1035.     

Towards a Characterization of the Locomotor Activity Rhythm of the Supralittoral Isopod Tylos europaeus

Freshly collected samples of Tylos europaeus from Korba beach (northeast of Tunisia) were housed in an environmental cabinet at controlled temperature (18°C?±?.5°C) and photoperiod. Locomotor activity was recorded under two photoperiodic regimens by infrared actography every 20?min by multichannel data loggers. One regimen simulated the natural light-dark cycle on the day of collection, whereas the second imposed a state of continuous darkness on all individuals. Under entraining conditions, the animals displayed rhythmic activity, in phase with the period of darkness, whereas in continuous darkness these isopods exhibited a strong endogenous rhythm with circadian and semidiurnal components at mean periods of τ (h:min)?=?25:09?±?01:02?h and τ?=?12:32?±?00:26?h, respectively. Under free-running conditions, this endogenous rhythm showed significant intraspecific variability. (Author correspondence: bohli.dhouha@gmail.com)     

Land use heterogeneity causes variation in demographic viability of a bioindicator of species-richness in protected fen grasslands

Land use change is one of the main drivers of species extinction. In Europe, grasslands are under active conflict between conservation efforts and increasing agricultural pressures. Here, we examine the demographic effects of differential land use on the herbaceous perennial Trollius europaeus L. (Ranunculaceae), a bioindicator of species-richness and ecosystem services in wet grasslands of Central Europe. Demographic data were collected in 2006–2009 from nine populations in seven protected sites of northeastern Germany representing four land use types. We constructed stage-based matrix population models to explore the effects of various land management on demographic viability of focal populations. We show that most studied populations are declining (λ < 1), although the estimates of local extinction vary between ≤15 years for grazed and woodland populations, and 20–99 years for mown and abandoned populations. The joint information from our elasticity analyses and life table response experiments revealed that reproduction, growth of small vegetative individuals and survival of reproductive stages are most important for population viability. Our study shows that the current land uses in protected areas where T. europaeus is found is incompatible with its long-term viability. We suggest that, when compatible with in situ practices, grasslands containing this species be mown after maturity in order to enhance seedling recruitment and to reduce competition for juveniles. Prolonged extinction times in abandoned populations offer a buffer to develop conservation schemes there. An improvement of conservation measures is urgently needed to maintain the populations of this important bioindicator and its associated community of moist species-rich fen grasslands.     

The ratio of leaf to total photosynthetic area influences shade survival and plastic response to light of green-stemmed leguminous shrub seedlings

Different plant species and organs within a plant differ in their plastic response to light. These responses influence their performance and survival in relation to the light environment, which may range from full sunlight to deep shade. Plasticity, especially with regard to physiological features, is linked to a greater capacity to exploit high light and is usually low in shade-tolerant species. Among photosynthetic organs, green stems, which represent a large fraction of the total photosynthetic area of certain species, are hypothesized to be less capable of adjustment to light than leaves, because of biomechanical and hydraulic constraints. The response to light by leaves and stems of six species of leguminous, green-stemmed shrubs from dry and high-light environments was studied by growing seedlings in three light environments: deep shade, moderate shade and sun (3, 30 and 100 % of full sunlight, respectively). Survival in deep shade ranged from 2 % in Retama sphaerocarpa to 74 % in Ulex europaeus. Survival was maximal at moderate shade in all species, ranging from 80 to 98 %. The six species differed significantly in their ratio of leaf to total photosynthetic area, which influenced their light response. Survival in deep shade increased significantly with increasing ratio of leaf to total photosynthetic area, and decreased with increasing plasticity in net photosynthesis and dark respiration. Responses to light differed between stems and leaves within each species. Mean phenotypic plasticity for the variables leaf or stem specific mass, chlorophyll content, chlorophyll a/b ratio, and carotenoid to chlorophyll ratio of leaves, was inversely related to that of stems. Although mean plasticity of stems increased with the ratio of leaf to total photosynthetic area, the mean plasticity of leaves decreased. Shrubs with green stems and a low ratio of leaf to total photosynthetic area are expected to be restricted to well-lit habitats, at least during the seedling stage, owing to their inefficient light capture and the low plasticity of their stems.     

欧夜鹰的繁殖生态与移巢行为

2008年6至8月及2018年6月和7月,采用实地观察、测量和红外相机监测方法对新疆乌鲁木齐郊外头屯河流域欧夜鹰（Caprimulgus europaeus）的栖息环境、巢间距、窝卵数、孵卵、育雏、幼鸟生长及移巢行为进行了调查和分析。利用红外相机监测3个巢,监测时间分别为 15 d、23 d和11 d,共拍摄照片8 462 张,视频4 152个片段,约40 h,经过筛选得到有效照片6 807张。结果表明,欧夜鹰的巢均置于河道中央的河心岛及乱石滩沙地上,周围植被稀疏。两巢间距最近为69 m,巢密度3 ~ 7个/km2。每窝产卵2枚（n = 7）,卵长径为（30.53 ± 0.88）mm,卵短径为（21.39 ± 0.85）mm,卵体积为（7.13 ± 0.50）cm3,卵重为（7.27 ± 0.38）g（n = 5）。孵卵期为15或16 d,孵卵期成鸟离巢觅食呈双峰型,分别在天黑后的20:00 ~ 21:00时和黎明前的03:00 ~ 04:00时。育雏期为16 ~ 18 d,育雏期和孵卵期成鸟活动强度存在明显的差异,成鸟喂食幼鸟亦呈双峰型,分别在夜里的20:30 ~ 22:30时和黎明前的02:30 ~ 04:30时。成鸟的行为谱可分为9类46种,幼鸟的行为谱可分为6类32种。雏鸟的体重、体长、翅长生长发育遵循Logistic方程规律,呈曲线变化,尾长、跗跖长和嘴峰长则遵循线性生长规律。欧夜鹰的移巢行为十分独特：一是为了躲避日晒,以避免幼鸟被阳光灼伤;二是避开干扰（天敌、牧群、洪水及人类活动等）。     

刺猬肌肉营养成份分析

对刺猬肌肉营养成分测定及其氨基酸分析,评价其营养价值。结果表明,刺猬肌肉(鲜样)中粗蛋白含量丰富(20.92±0.14)%,肌肉中含18种氨基酸,占肌肉总量的80.13%(干样百分比),其中人体必需氨基酸8种,占氨基酸总量的46.88%,必需氨基酸指数(EAAI)为64.58,氨基酸构成比例符合FAO/WHO标准;鲜味氨基酸总量为30.82%;钙和铁的含量分别为33.8mg/100g和11.0mg/100g。说明其具有较高的营养和食用价值。