Intricate evolutionary histories in montane species: a phylogenetic window into craniodental discrimination in the Peromyscus mexicanus species group (Mammalia: Rodentia: Cricetidae)

Mountain‐associated species, which exhibit allopatric distributions associated with elevation, endemisms and complex evolutionary histories, pose challenging evolutionary scenarios in which to discern the diversification of species. The Peromyscus mexicanus mice group, distributed along mountains in southern Mexico and Central America, is morphometrically variable, a key rationale for the ongoing controversy regarding its species delimitation. Based on the recognized 15 mitochondrial lineages for the group, we analysed external and craniodental morphometric variables to test whether lineages can be differentiated morphometrically and allow for the delimitation of species. We also aimed to test the prediction that the phylogenetic structure of the morphometric data is concordant with that of the molecular information. Based on 19 craniodental measurements from 521 specimens, multivariate and discriminant analyses showed that lineages are morphometrically discernible, representing distinct phenotypes, and that overall size and mandible measurements are significant features that discriminate lineages, supporting hypotheses about differences in feeding habits between species. Also, a pattern of increasing size with elevation was observed, further supported by specific morphological differences exhibited between highland and lowland lineages inhabiting the same mountain. Our results demonstrate that P. mexicanus is both genetically and morphometrically variable, where most highland montane species are differentiated from lowland species; also, a significant correlation between mitochondrial and morphometric information is indicative of phenetic concordance, altogether in agreement with a recent taxonomic proposal for the group. We suggest that the group's intricate diversification responds to ecological diversification and adaptation to a variety of mountain habitats and Pleistocene biogeographic climatic dynamics.     

Home sweet home: evidence for nest‐fidelity in the rocky intertidal fish,the shanny Lipophrys pholis

The ability to be faithful to a particular area or site was analysed in the shanny Lipophrys pholis. Using passive integrated transponders, adults from a population of L. pholis at Cabo Raso, Portugal, were followed over a period of 3 years. The findings showed that site fidelity is a consistent behaviour during the breeding season with specific breeding males being found only in particular sectors within the area, and in specific nests throughout the years. The fact that, in general, L. pholis individuals were absent from the study area during the non‐breeding season and breeding males were recorded returning to the same nests and sectors for consecutive breeding seasons suggests that they have developed excellent homing abilities. Translocation data corroborate this idea showing that breeding males successfully returned to their nests after a displacement of >100 m. Altogether, these findings highlight the relevance of life‐history traits (e.g. nesting) in the conditioning of site fidelity and homing for this species of rocky intertidal fish, and more importantly, provide evidence for the need of a well‐developed navigational system.     

陕北黄土丘陵沟壑区坡沟立地环境下幼苗的存活特征

幼苗是植被恢复演替的基础, 在生态系统中具有非常重要的作用。为了探索黄土丘陵沟壑区坡沟立地环境下幼苗的存活特征, 在陕西省安塞县宋家沟和纸坊沟流域设置15个固定样地进行定点动态监测, 运用单因素方差分析法和系统聚类分析法对不同立地环境下的幼苗密度和幼苗存活率进行了分析。结果表明: 1)不同坡沟立地环境下, 幼苗存活特征差异明显, 整体表现为阳坡幼苗密度较小而存活率较高, 阴坡幼苗密度较大但存活率较低。2)细裂叶莲蒿(Artemisia gmelinii)、菊叶委陵菜(Potentilla tanacetifolia)、阿尔泰狗娃花(Heteropappus altaicus)等物种具有较高的幼苗存活率, 在生存竞争中幼苗是以“质”取胜; 而猪毛蒿(Artemisia scoparia)、中华苦荬菜(Ixeris chinensis)、阴行草(Siphonostegia chinensis)等物种具有较高的幼苗密度, 在生存竞争中是以“量”取胜。3)同一物种在坡沟立地环境下表现出不同的存活曲线, 不同物种在不同立地环境下也可呈现同一存活曲线; 细裂叶莲蒿、菊叶委陵菜、长芒草(Stipa bungeana)、阿尔泰狗娃花、兴安胡枝子(Lespedeza davurica)等物种, 幼苗不仅在雨季存活能力强且具有较强的越冬能力; 猪毛蒿、香青兰(Dracocephalum moldavica)、臭蒿(Artemisia hedinii)等物种在雨季前幼苗存活能力较强, 但冬季存活能力弱。4)坡面不同微环境下幼苗存活特征也存在差异, 即微环境的改变在一定程度上影响着幼苗的生长、存活和越冬。因此, 在黄土丘陵沟壑区应根据物种幼苗存活特性对幼苗进行适当的抚育管理, 这将有利于幼苗的建植和植被更新。     

Characterization of moorland vegetation and the prediction of bird abundance using remote sensing

Aims To characterize and identify upland vegetation composition and height from a satellite image, and assess whether the resulting vegetation maps are accurate enough for predictions of bird abundance. Location South‐east Scotland, UK. Methods Fine‐taxa vegetation data collected using point samples were used for a supervised classification of a Landsat 7 image, while linear regression was used to model vegetation height over the same image. Generalized linear models describing bird abundance were developed using field‐collected bird and vegetation data. The satellite‐derived vegetation data were substituted into these models and efficacy was examined. Results The accuracy of the classification was tested over both the training and a set of test plots, and showed that more common vegetation types could be predicted accurately. Attempts to estimate the heights of both dwarf shrub and graminoid vegetation from satellite data produced significant, but weak, correlations between observed and predicted height. When these outputs were used in bird abundance–habitat models, bird abundance predicted using satellite‐derived vegetation data was very similar to that obtained when the field‐collected data were used for one bird species, but poor estimates of vegetation height produced from the satellite data resulted in a poor abundance prediction for another. Conclusions This pilot study suggests that it is possible to identify moorland vegetation to a fine‐taxa level using point samples, and that it may be possible to derive information on vegetation height, although more appropriate field‐collected data are needed to examine this further. While remote sensing may have limitations compared with relatively fine‐scale fieldwork, when used at relatively large scales and in conjunction with robust bird abundance–habitat association models, it may facilitate the mapping of moorland bird abundance across large areas.     

周边区域湿地景观变化对洪河保护区涉禽栖息地的影响

以三江平原洪河国家级保护区及其周边3个农场为研究区域,利用GIS技术和栖息地评价模型方法,探讨了周边区域湿地景观变化对保护区内景观结构以及丹顶鹤、东方白鹳栖息地的影响。结果显示：（1）自1983年区域土地开发以来,周边区域湿地景观面积减少了63％,景观类型多样性趋于单一化;（2）保护区内湿地景观结构改变明显,类型多样性呈降低趋势,丹顶鹤和东方白鹳栖息地面积和空间分布均发生变化;（3）保护区与周边区域湿地景观连通度降低了70％,其结果严重改变了保护区与周边区域的景观生态联系,削弱了保护区原有湿地景观多样性和涉禽栖息地功能;（4）必须从景观尺度,恢复保护区周边一定面积的湿地景观结构,维持保护区与周边区域适当的景观生态联系,是有效管理和维护保护区可持续发展的最佳手段之一。     

Speciation in the highlands of Mexico: genetic and phenotypic divergence in the Mexican jay (Aphelocoma ultramarina)

The pine-oak woodlands of the Mexican highlands harbour significant biological diversity, yet little is known about the evolutionary history of organisms inhabiting this region. We assessed genetic and phenotypic differentiation in 482 individuals representing 27 populations of the Mexican jay ( Aphelocoma ultramarina ) — a widespread bird species of the Mexican highlands — to test whether populations in the central and northern Mexican sierras display discrete breaks between groups, which would be consistent with a role for the different mountain chains in divergence and speciation. We found abrupt breaks in mitochondrial DNA (mtDNA; ND2 and control region) delineating four major genetic groups found in the Sierra Madre Occidental, Sierra Madre Oriental, southern Central Plateau (Bajio), and Transvolcanic Belt. These mtDNA groups were largely corroborated by data from nuclear microsatellites and phenotypic data, except that clades from the Central Plateau and Sierra Madre Oriental showed clinal change in these data sets. Uncertainty about the mutation rate for our mitochondrial markers warrants considerable caution with regard to estimating divergence times, but the major genetic groups appear to have split before the most extreme period of glacial cycling that marked the last 0.7 million years and after Mexico's period of major mountain formation. The fact that some genetic breaks do not coincide with well-known geographic barriers suggests a role for ecology in divergence and speciation, and we discuss implications for taxonomy and conservation.     

蝗虫生境监测方法研究进展

蝗虫是一种能对农业生产带来毁灭性打击的害虫。预测、监测蝗虫的发生、发展对于防治蝗虫、减轻蝗灾具有重要意义。在分析蝗虫的发生和消长与其生存环境的关系基础上,概述了以往蝗虫发生、发展预测、监测的主要方法。然后,从监测蝗虫生境采用的指标、卫星数据、算法等方面进一步阐述了运用现代遥感、地理信息系统技术监测蝗虫生境、预测蝗虫发生、发展的理论基础和最新进展;最后,结合现代对地观测技术、网络、快速计算和模拟等技术的发展探讨了蝗虫生境监测的发展方向。     

Forest fragmentation and rhinocryptid nest predation in central Chile

Fragmentation of forest landscapes can raise the intensity of nest predation by increasing the abundance and richness of generalist or introduced predators. Understory foraging birds, such as rhinocryptids, can be highly vulnerable to nest predation in fragmented landscapes because they often place their nests on the ground. Temperate deciduous forests in Chile have been intensively fragmented in the last centuries, causing changes in nest predator densities. We tested if predation of artificial nests, mimicking those of rhinocryptids, placed on and above ground was higher in the remnant fragments of central Chile due to an increase in predator abundance. The rate of nest predation in forest remnants was larger than in native continuous forest. Small mammals were the main nest predators. Despite high predation rates, the abundance of rhinocryptids is higher in forest remnants, suggesting that fragments might constitute ecological traps.     

Site prioritisation for the protection of rare subterranean species – the cases of two ostracods from south-western France

1. Delineation of protected areas for rare subterranean species is a key problem for groundwater biodiversity conservation, because of practical difficulties in implementation. Criteria for site selection are presented that are derived from studies on two remarkable Ostracoda, Dolekiella europaea Gidó, Artheau, Colin, Danielopol & Marmonier (Limnocytheridae) and Vestalenula carveli Artheau (Darwinulidae) discovered in south-western France.
2. Arguments for natural heritage value and protection of subterranean species are proposed and illustrated by using information on these two ostracod species. The proposed criteria are: (i) local and/or regional endemism; (ii) known occurrence of the species at a few localities only; (iii) representativeness for ancient phylogenetic lineages with wider geographical distributions in the past; and (iv) suitability for scientific study because of unique morphological or biological traits.
3. It is also proposed to prioritise the protection of subsurface sites using the following criteria: (i) type locality for newly described species; (ii) presence of other rare stygobiotic taxa; and (iii) high population densities of the primary target species.
4. Development and implementation of protection strategies at local scale are likely to benefit from collaboration between scientists, policy makers and stakeholders. The measures taken should complement existing national and/or international attempts at large-scale protection of groundwater biodiversity.     

Comparing Relative Model Fit of Several Species-Accumulation Functions to Local Papilionoidea and Hesperioidea Butterfly Inventories of Mediterranean Habitats

When compiling an inventory of hyperdiverse taxa, it is impossible to record the total number of species during fieldwork. To ensure the accuracy of species-richness data it is necessary to assess the reliability of inventories. Accumulation curves are an easy method for doing this and are extensively described in the literature. In this study, we compare the relative fit of various models of species-accumulation functions for six local butterfly inventories, evaluating them by a consideration of the values of the fit, coefficient of determination and sum-of-squares, and the residual patterns and Akaike’s Information Criterion. In general, complex functions, such as the Weibull or Chapman-Richards, performed better than simpler and more widely used models (e.g., the Clench and negative exponential models). The performance of models varied among sampling plots, indicating the influence of factors such as land use and community structure. Thus, although the application of more complex models should replace the use of simple ones, further research into the factors affecting model fit of accumulation functions is necessary.