Adaptations to overwintering in the earthworm Dendrobaena octaedra: Genetic differences in glucose mobilisation and freeze tolerance

Geographic variation in freeze tolerance, glycogen storage and freeze-induced glucose mobilisation was investigated in the earthworm Dendrobaena octaedra. Specimens from 15 populations collected in Canada, Greenland and Europe were reared in the laboratory in a common-garden experiment to test whether glucose and glycogen concentrations correlated with genetic variation in freeze tolerance among the populations. Populations from Canada, Sweden, Poland and Finland did not differ much in their freeze tolerance and were able to tolerate freezing for 18 d down to at least −14 °C (lowest temperature tested). Specimens collected in a relatively warm climate (Denmark) were the least freeze tolerant, and also had the lowest concentrations of glucose when frozen at −2 °C. However, there was no clear evidence that glucose concentration is a determinant in the degree of freeze tolerance of D. octaedra when considering the whole assemblage of populations. The role of phylogenetic inertia was tested by looking for serial independence and no influence of phylogeny was detected in our findings allowing us to exclude the possibility that phylogenetic relatedness between populations is a major evolutionary factor explaining the observed differences for freeze tolerance and related traits. The size of the glycogen reserve was significantly correlated with the ability to tolerate freezing. Large glycogen reserves may be advantageous in very cold regions in order to maximise cryoprotectant production and/or as a source of energy for the anaerobic metabolism occurring during prolonged freezing.     

Effect of cadmium on life-history parameters in Dendrobaena octaedra (Lumbricidae: Oligochaeta) populations originating from forests differently polluted with heavy metals

This study examined whether earthworm (Dendrobaena octaedra) populations originating from three differently polluted mixed oak-pine forests differ in life history parameters, and whether any observed differences are adaptive. Three forests were chosen: the most polluted forest, near Olkusz, affected by a zinc smelter and on soil containing metal ore; the Niepo?omice Forest, moderately polluted by industry; and the relatively unpolluted Kampinoska Forest. Parent animals (P generation) were collected from each forest and thereafter cultured in the laboratory. From cocoons laid in the laboratory the F1 generation was reared and observed to determine whether it inherited features observed in the parent generation. To distinguish the effect of the metal studied (Cd) from that of soil edaphic conditions, individuals collected in the field were divided into two groups: one cultured in unpolluted medium, the other in medium spiked with cadmium. Earthworms originating from polluted forests (parent generation) exhibited higher cadmium storage capacity, and a higher cadmium concentration factor (cadmium in animal/cadmium in soil). No interpopulation differences in cadmium accumulation were found in their offspring (F1 generation), meaning that the cadmium accumulation ability was acclimatory and not adaptive. Cadmium in low doses negatively affected reproduction parameters: cocoon production, mass of produced cocoons, and reproductive allocation (weight of offspring divided by the weight of adults). The effect of cadmium was stronger in animals originating from the unpolluted forest than in those from the heavily polluted forest. F1 animals originating from the heavily polluted forest exhibited the highest cadmium tolerance (higher mean survival time and median survival time, lower hazard rate probability per time unit that an individual surviving to the beginning of a given interval will die within that interval). The observed tolerance to cadmium (higher reproduction, better survival) in the population from the heavily polluted forest apparently was heritable, suggesting adaptation of D. octaedra to life in a polluted environment.     

Does the acephaline gregarine Monocystis sp. modify the surface behaviour of its earthworm host Lumbricus terrestris?

The earthworm Lumbricus terrestris has relatively low dispersal rates. This can represent a challenge for the internal gregarine parasite Monocystis, the dispersal of which often depends on the host. Mating of Monocystis can also be restricted to parasite stages within the current host individual. Adaptations, including host behavioural modification, that improve parasite transmission and simultaneously avoid inbreeding within a single host individual should be favoured by selection. We used a correlative approach to investigate the question of parasitic manipulation in this Gregarine-Lumbricid system. We observed mature earthworms (n=24) for 3 weeks while recording various measures of activity (surface activity, burrowing activity, surfacing delay, number of surface visits) and correlated parasite load with these activity measures. We found a significant positive correlation between surface activity and midden (or cast) production, which suggests a simple method for assessing the overall activity of local earthworm populations. However, we found no evidence of behavioural manipulation of any measure of host activity. We discuss these results in the context of inbreeding depression and host-parasite coevolution.     

气候变化对青海省种植业的影响及适应对策

从青海省种植业存在结构单一、为畜牧业提供的饲草(料)有限、春播作物收获后的水热资源没有充分利用等现状出发，结合青海省未来气候暖干化的发展趋势，提出了青海省种植业结构调整对策：如实行农区兴林、旱区兴牧；利用春播作物收获后的余热资源提高复种指数；利用冬、春季增温明显的气候特点扩大冬小麦的种植面积等。     

盐生植物的盐渍适应性及利用价值

概述了盐生植物的概念、分类及对盐渍环境的适应性，重点探讨了盐生植物的开发利用及在盐碱地改良中所发挥的重要作用。     

长白山区松口蘑分布及生态研究

本文调查了长白山区松口蘑的分布状况,发现了一些新的松口蘑产区,研究了植被土壤等生态特征,讨论了松口蘑的适应性和驯化潜能等前沿问题。     

Effects of repeated hypoxia on the NPY-like immunoreactivity in the mouse brain

AIM:To observe the effects of repeated hypoxia on the neuropeptide Y(NPY)-like immunoreactivity in the mouse brain. METHODS:Forty male kunming mice were divided into 5 groups: Control, H₁(after the 1^sthypoxic run), H₂(the 2^nd hypoxic run), H₃(the 3^rdhypoxic run)and H₄(the 4^th hypoxic run). The hypoxic groups were subjected to different runs of hypoxia exposure. The NPY-like immunoreactivity in the moue brain was measured by using radioimmunoassary method.RESULTS: The standard tolerance time of the mouse exposed to hypoxia significantly increased following each increase in runs of hypoxia exposure. After the 1^st and 2^nd hypoxic run the NPY-like immunoreactivities in the mice brain significantly increased by 145.5%±3.2% and 147.3%±2.5% compared with the control(P＜0.01), respectively. However, the NPY-like immunoreactivites returned to the control levels after the 3^rd run. CONCLUSION:The repeated exposure to hypoxia can significantly enhance mouse's tolerance to hypoxia by preconditioning, and can induce the increase by only one exposure in NPY-like immunoreactivities of the mouse brain during the early period of formation of hypoxic preconditioning.     

豫西地区冬小麦春播及春麦引种效果简报

基于小麦应变栽培需要,对豫西地区春季播种冬小麦和引进春小麦品种观察分析,结果表明:2月中旬前播种或3月上旬前出苗的豫麦18小麦品种,在豫西地区可收获产量,但产量较低;春小麦产量一般高于春季同期播种冬小麦产量,但应选择成熟早,灌浆快,后期耐高温品种,注意适期早播,提高穗粒重。     

Adapting conservation efforts to face climate change: Modifying nest-site provisioning for lesser kestrels

Adaptation to climate change has recently become a crucial element on the climate change policy agenda as it is now recognized that even the most stringent mitigation efforts may not arrest the effects of climate warming. The ecological impacts and costs of predicted weather-related extreme events, such as extreme temperatures, are not fully understood and may present unexpected challenges to conservationists that require solutions. In Portugal, provisioning of artificial nests has been the main driver of the spectacular increase in the endangered lesser kestrel population. Nevertheless, atypically high temperatures recorded during the 2009 breeding season coincided with a mortality of 22% of surveyed chicks in provided nests. Hot days did not affected prey delivery rates to the nestlings, suggesting that the die-off was due to chicks’ acute dehydration. Chick mortality was significantly higher amongst younger individuals. Within survivors, physiological costs of high temperatures significantly affected chick growth and body condition at fledging. Nest-site microclimate was influenced by nest-type and compass orientation: wooden nest-boxes attained the highest temperatures, exceeding 55 °C when facing south, so explaining the recorded higher mortality, lower growth rates and lower fledging body condition among broods in these nests. Simulated scenarios of global warming with increasing occupation rate of artificial nests due to reductions in alternatives predicted a reduction in population growth rate. In the worst scenario, with a 100% occupancy of nest-boxes, the population growth would decline on average 7% per year. The impact of high temperatures on lesser kestrel breeding success highlights a need for actions to modify and research to adapt conservation efforts and future planning to account for climate change.     

国家重点保护植物绵刺的适应性及其保护的研究

绵刺是蒙古高原特有的单种属植物，已列为国家二级重点保护植物。本文系统地综述了绵刺的生态生物学特性，并探讨了其适应性，研究结果表明，绵刺具有典型旱生植物的结构和特征，耐旱、耐贫瘠、耐盐碱和抗风蚀能力较强，对恶劣的环境条件具有良好的适应性。文章还分析了绵刺濒危的可能原因，并提出了保护措施。