层次分析法在自然保护区公路路线方案选择中的应用

针对自然保护区公路路线方案选择中存在的盲目性、片面性和主观性问题，本文以环长白山旅游公路建设项目环境影响评价方案为例，提出运用层次分析法进行路线方案比选。结果表明，在公路环境影响评价的路线方案选择过程中，层次分析法是一种较好的定量分析方法。     

宁夏冰雹的分布特征

应用1961～2004年宁夏各气象站地面观测资料，统计分析了宁夏冰雹的时空分布特征，探讨了宁夏冰雹产生的主要源地和移动路径。分析表明：20世纪80年代为宁夏冰雹频发期，90年代有减少的趋势；近10年来冰雹大为减少，年际变化比较大，有一定的周期性。冰雹多发生于春末至盛夏，6月为频发期；87％出现在中午至傍晚前后；71．84％的降雹持续时间在1～10min之间。初雹最早发生在3月中旬，终雹最晚结束在10E下旬。有2个频发中心，即宁夏南部的六盘山区和北部的贺兰山区，有“山地多、平川少、南北多、中部少”的地域分布特征。降雹线大部分呈NW—SE走向，移动路径多从西北向东南方向移动；主要发源于六盘山系和贺兰山沿山。     

避免不可抗力对工厂安全的威胁

洪水、地震、泥石流、台风等不可抗力对工厂安全造成威胁,因此厂址选择阶段如何考虑不可抗力因素,如何处理不可抗力因素与其它建厂条件间的关系十分重要.提出如何避免或减小不可抗力对工厂安全的威胁,并列举工程实例进一步说明处理方法.     

Nest selection by snow petrels Pagodroma nivea in East Antarctica: Validating predictive habitat selection models at the continental scale

Little is known on the factors controlling distribution and abundance of snow petrels in Antarctica. Studying habitat selection through modeling may provide useful information on the relationships between this species and its environment, especially relevant in a climate change context, where habitat availability may change. Validating the predictive capability of habitat selection models with independent data is a vital step in assessing the performance of such models and their potential for predicting species’ distribution in poorly documented areas.From the results of ground surveys conducted in the Casey region (2002–2003, Wilkes Land, East Antarctica), habitat selection models based on a dataset of 4000 nests were created to predict the nesting distribution of snow petrels as a function of topography and substrate. In this study, the Casey models were tested at Mawson, 3800 km away from Casey. The location and characteristics of approximately 7700 snow petrel nests were collected during ground surveys (Summer 2004–2005). Using GIS, predictive maps of nest distribution were produced for the Mawson region with the models derived from the Casey datasets and predictions were compared to the observed data. Models performance was assessed using classification matrixes and Receiver operating characteristic (ROC) curves. Overall correct classification rates for the Casey models varied from 57% to 90%. However, two geomorphologically different sub-regions (coastal islands and inland mountains) were clearly distinguished in terms of habitat selection by Casey model predictions but also by the specific variations in coefficients of terms in new models, derived from the Mawson data sets. Observed variations in the snow petrel aggregations were found to be related to local habitat availability.We discuss the applicability of various types of models (GLM, CT) and investigate the effect of scale on the prediction of snow petrel habitats. While the Casey models created with data collected at the nest scale did not perform well at Mawson due to regional variations in nest micro-characteristics, the predictive performance of models created with data compiled at a coarser scale (habitat units) was satisfactory. Substrate type was the most robust predictor of nest presence between Casey and Mawson. This study demonstrate that it is possible to predict at the large scale the presence of snow petrel nests based on simple predictors such as topography and substrate, which can be obtained from aerial photography. Such methodologies have valuable applications in the management and conservation of this top predator and associated resources and may be applied to other Antarctic, Sub-Antarctic and lower latitudes species and in a variety of habitats.     

Importance of movement constraints in habitat selection studies

The aim of this study is to empirically illustrate the importance of taking movement constraints into account when testing for habitat selection with telemetry data. Global Positioning System relocations of two Scandinavian brown bears were used to compare the results of two different tests of habitat selection by the bears within their home range. Both relied on the comparison of observed dataset with datasets simulated under the hypothesis of random habitat use. The first analysis did not take movement constraints into account (simulations were carried out by randomly distributing a set of points in the home range) whereas the second analysis accounted for these constraints (simulations were carried out by building random trajectories in the home range). The results for the two analyses showed contrasted results. Therefore, not accounting for movement constraints in analyses may result in a misleading biological interpretation. Autocorrelation between relocations is not undesirable: it contains information about ecological processes that should be integrated in habitat selection analyses.     

Comparing environmental influences on coral bleaching across and within species using clustered binomial regression

Differential susceptibility among reef-building coral species can lead to community shifts and loss of diversity as a result of temperature-induced mass bleaching events. We evaluate environmental influences on coral colony bleaching over an 8-year period in the Florida Keys, USA. Clustered binomial regression is used to develop models incorporating taxon-specific responses to the environment in order to identify conditions and species for which bleaching is likely to be severe. By building three separate models incorporating environment, community composition, and taxon-specific responses to environment, we show observed prevalence of bleaching reflects an interaction between community composition and local environmental conditions. Environmental variables, including elevated sea temperature, solar radiation, and reef depth, explained 90% and 78% of variability in colony bleaching across space and time, respectively. The effects of environmental variables were only partially explained (33% of variability) by corresponding differences in community composition. Taxon-specific models indicated individual coral species responded differently to local environmental conditions and had different sensitivities to temperature-induced bleaching. For many coral species, but not all, bleaching was exacerbated by high solar radiation. A 25% reduction in the probability of bleaching in shallow locations for one species may reflect an ability to acclimatize to local conditions. Overall, model results indicate predictions of coral bleaching require knowledge of not just the environmental conditions or community composition, but the responses of individual species to the environment. Model development provides a useful tool for coral reef management by quantifying the influence of the local environment on individual species bleaching sensitivities, identifying susceptible species, and predicting the likelihood of mass bleaching events with changing environmental conditions.     

The role of migration and founder effect for the evolution of cooperation in a multilevel selection context

The idea that natural selection can be meaningfully applied at the group level may be more important than previously thought. This perspective, a modern version of group selection, is called multilevel selection. Multilevel selection theory could incorporate previous explanations for the evolution of cooperation including kin selection. There is general agreement that natural selection favors noncooperators over cooperators in the case of an unstructured population. Therefore, the evolution of cooperation by multilevel selection often requires positive assortment between cooperators and noncooperators. The question is how this positive assortment can arise in the ecological meaning. We constructed an individual-based model of multilevel selection and introduced migration and evolution. The results showed that positive assortment was generated especially when a migration strategy was adopted in which individuals respond specifically to bad environmental conditions. It was also shown that the founder effect in the evolutionary process could further facilitate positive assortment by working with migration. We analyzed assortment by using relatedness defined in group-structured populations. The fact that cooperation was achieved by such migration and by the founder effect highlights the importance of sensitiveness to the ecological environment and of fluctuations in group size, respectively.     

Potential direct fitness consequences of ornament-based mate choice in a butterfly

Female mate choice has been shown to provide direct mating benefits in several animal groups. In butterflies, for which there are increasing reports of fine-scale color-based mate choice, the evolutionary benefits that accrue from such mating biases, if any, are largely unknown. We addressed this issue in the butterfly Colias eurytheme, a species in which females choose mates on the basis of iridescent ultraviolet (UV) wing ornamentation and in which males donate reproductively beneficial nuptial gifts. In the first experiment, we assessed the mass of gifts donated to 77 virgin females by males sampled directly from a field encounter site. Despite large variance in the male adult phenotype and ejaculate, no single aspect of dorsal wing coloration, including UV brightness, chroma, or hue, was related to ejaculate mass. There was, however, an interesting interaction between the effects of male body size and copula duration upon ejaculate mass, with size scaling positively with ejaculate mass among males involved in shorter copulations (those lasting <70 min) but negatively among males in longer copulations. In the second experiment, we assessed the lifetime fecundity, fertility, and longevity of 85 females mated under similar circumstances to free-flying wild males. Although several wing color parameters proved subtly informative in more sophisticated multivariable models, no model predicted more than about 20% of the variation in any single female fitness parameter. The duration of copulation, which ranged from 35 min to over 16 h and which carries putative costs for females, was, again, only very weakly predicted by male wing color parameters (i.e., R ² = 0.089). Given the overall minor predictive power of male wing coloration in general and of UV brightness in particular, our results do not strongly support the hypothesis that female C. eurytheme prefer bright UV males to obtain direct benefits or to minimize the costs associated with lengthy copulations.     

Carotenoid-based ornamentation as a dynamic but consistent individual trait

Carotenoid-based ornaments act as signals of quality in many animal species. In contrast to feathers, which are relatively stable structures, carotenoid-pigmented integuments (e.g. bills, lores, tarsi) can change colour rapidly and may better reflect changes in physiological condition. I studied the seasonal variations in plasma carotenoids in red-legged partridges (Alectoris rufa) kept on a constant diet and free of intestinal parasites. Furthermore, I analyzed whether seasonal changes in circulating carotenoids were mirrored by the carotenoid-based coloration of eye rings and bill of this species. Plasma carotenoids showed seasonal variation, with higher levels coinciding with the end of the mating and the start of the laying season. Eye ring pigmentation was related to plasma carotenoid levels, and changes in bill hue (but not changes in UV or red bill chroma) mirrored the variation in plasma carotenoids during the breeding season. Despite the seasonal variation, individual differences in eye ring pigmentation and bill hue, UV and red chroma were consistent throughout the breeding season. Similarly, individual differences in eye ring pigmentation and bill hue and red chroma remained consistent between consecutive years. These results suggest that carotenoid based integumentary colorations act as dynamic traits that accurately reflect the carotenoid-status of individuals, thus reliably indicating consistent differences in individual quality. Furthermore, variability in signal expression appears to have a relevant genetic/phenotypic basis independently of environmental conditions. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

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.