Continent‐scale global change attribution in European birds ‐ combining annual and decadal time scales

Species attributes are commonly used to infer impacts of environmental change on multiyear species trends, e.g. decadal changes in population size. However, by themselves attributes are of limited value in global change attribution since they do not measure the changing environment. A broader foundation for attributing species responses to global change may be achieved by complementing an attributes‐based approach by one estimating the relationship between repeated measures of organismal and environmental changes over short time scales. To assess the benefit of this multiscale perspective, we investigate the recent impact of multiple environmental changes on European farmland birds, here focusing on climate change and land use change. We analyze more than 800 time series from 18 countries spanning the past two decades. Analysis of long‐term population growth rates documents simultaneous responses that can be attributed to both climate change and land‐use change, including long‐term increases in populations of hot‐dwelling species and declines in long‐distance migrants and farmland specialists. In contrast, analysis of annual growth rates yield novel insights into the potential mechanisms driving long‐term climate induced change. In particular, we find that birds are affected by winter, spring, and summer conditions depending on the distinct breeding phenology that corresponds to their migratory strategy. Birds in general benefit from higher temperatures or higher primary productivity early on or in the peak of the breeding season with the largest effect sizes observed in cooler parts of species' climatic ranges. Our results document the potential of combining time scales and integrating both species attributes and environmental variables for global change attribution. We suggest such an approach will be of general use when high‐resolution time series are available in large‐scale biodiversity surveys.     

Spatial variation in adult sex ratio across multiple scales in the invasive golden apple snail,Pomacea canaliculata

Adult sex ratio (ASR) has critical effects on behavior and life history and has implications for population demography, including the invasiveness of introduced species. ASR exhibits immense variation in nature, yet the scale dependence of this variation is rarely analyzed. In this study, using the generalized multilevel models, we investigated the variation in ASR across multiple nested spatial scales and analyzed the underlying causes for an invasive species, the golden apple snail Pomacea canaliculata. We partitioned the variance in ASR to describe the variations at different scales and then included the explanatory variables at the individual and group levels to analyze the potential causes driving the variation in ASR. We firstly determined there is a significant female‐biased ASR for this species when accounting for the spatial and temporal autocorrelations of sampling. We found that, counter to nearly equal distributed variation at plot, habitat and region levels, ASR showed little variation at the town level. Temperature and precipitation at the region level were significantly positively associated with ASR, whereas the individual weight, the density characteristic, and sampling time were not significant factors influencing ASR. Our study suggests that offspring sex ratio of this species may shape the general pattern of ASR in the population level while the environmental variables at the region level translate the unbiased offspring sex ratio to the female‐biased ASR. Future research should consider the implications of climate warming on the female‐biased ASR of this invasive species and thus on invasion pattern.     

COMPARATIVE CYTOLOGY AND TAXONOMY OF THE ULVAPHYCEAE. I. THE ZOOSPORE OF ULOTHRIX ZONATA (CHLOROPHYTA)1

This fine structural study of the quadriflagellate zoospore of Ulothrix zonata (Weber & Mohr) Kützing, with special attention to the flagellar root system, demonstrates that it is very similar to the zoospore of Ulva lactuca L. in several aspects. Common features include the presence of a cruciate root system (4-2-4-2 type), a non-striated band that connects basal bodies, a so-called terminal cap, and system I and system II striated root components. Only slight differences exist, i.e. in the shape of the terminal cap, and in the number and position of the system II root components. It is concluded that the taxonomic affinities of U. zonata lie with the Ulvaphyceae sensu Stewart and Mattox rather than with the Chlorophyceae. Additional support for this conclusion is the discovery of tiny, flat body scales on the zoospore of U. zonata. A summary of the distinctive characteristics of the Chlorophyceae, Charophyceae and Ulvaphyceae reflecting the current state of knowledge is given.     

An enigmatic actinopterygian (Pisces: Osteichthyes) from the Upper Permian of China

A new actinopterygian fish Yaomoshania minutosquama gen. & sp. nov., from the Upper Permian of the Dzungaria [Junggar] Basin in China is described. The material consists of two very fragmentary specimens showing almost exclusively scale rows. The arrangement of the scale rows of the holotype resembles the reversion lines of acanthodian caudal fins and of cheirolepids. The size and shape of the scales, and the diminishing size of the scales along the rows, is similar to those of acanthodians and those actinopterygians with small scales such as Cheirolepis. However, the histology of the scales demonstrates features that are found in more advanced actinopterygians: superimposed ganoine lamellae, the arrangement of dentine tubules and pulp canals, buried odontodes stacked on each other to make the ornamental ridges, and an asymmetric pattern of growth achieved by extensive remodelling (resorption and redeposition) of all layers of the scale. Yaomoshania minutosquama is proposed as a small-scale bearing, basal actinopterygian, different from Cheirolepis , but characterized by advanced histological characters.     

Comparative morphology and evolutionary aspects of the reflective under wing scale-pattern in Fritillary butterflies (Nymphalidae: Argynnini)

The wing scale ultrastructure of the reflective under wing pattern found in many Argynnini butterflies are examined for all recognised genera and subgenera and compared to that of some basal Heliconiini. A true reflective pattern probably evolved once within the Argynnini. But the phylogenetic information in these structures is limited due to a high degree of homoplasy in the scale ultrastructure related to the reflective patterns. The degree of specialisation is also homoplastic. The general morphological modification responsible for the reflective patterns seems to be a “closing” of the large windows, which generally occupy most of the inter-ridge space on the abwing surface in the scales of higher Lepidoptera. The fact that the Argynnis niobe morphs with a silvery pattern have scales with ‘closed windows’ whereas the Argynnis niobe morphs without a silvery pattern have typical non-reflective scales with very large windows supports this conclusion.The degrees of modification of the scales, including whether both cover and ground scales or only cover scales are modified, are to some extent correlated to the degree of reflectiveness in the wing pattern. Boloria eunomia has, as the only species, more modified ground scales than cover scales.     

Relationships between stream macroinvertebrates and environmental variables at multiple spatial scales

1. Aquatic communities are structured by multiple forces, and identifying the driving factors over multispatial scales is an important research issue. The East Asian monsoon region is globally one of the richest environments in terms of biodiversity, and is undergoing rapid human development, yet the river ecosystems in this region have not been well studied. We applied a hierarchical framework to incorporate regional and local environmental effects on stream macroinvertebrate communities in this region. The knowledge gained is expected to improve the understanding of the importance of spatial scale on regional and local diversity in the East Asian monsoon region. 2. A national data set of benthic macroinvertebrates and environmental variables (geographical, land‐use, hydrological, substratum and physicochemical elements) in Korean rivers was used to determine the habitat preferences of macroinvertebrates. 3. Latitude, proportion of forest coverage, riffle habitat, silt substratum and temperature were the most important determinants for the ordinations of macroinvertebrate communities in each category evaluated by canonical correspondence analysis (CCA). The optimal habitats for stream macroinvertebrates are not the same for all species, and overall community metrics and abundance of sensitive species tended to be lower in open agricultural and urban streams than in forested streams. The sensitivity of mayflies and stoneflies to anthropogenic disturbances implicated them as good indicators to assess the effects of urban and agricultural activities. 4. A partial CCA was used to evaluate the relative importance of macrohabitat and microhabitat variables on community composition at three spatial scales (whole country, the large Han River basin and two small sub‐basins in the lowlands and highlands). The majority of community variation (17–22% for each environmental element) was explained by macrohabitat variables at the regional spatial scale. In contrast, large proportions (15–18%) were explained by microhabitat variables at the local spatial scale. 5. Our findings indicate that the relative importance of habitat scales should be determined by geographical size and that comprehensive understanding of multispatial scale patterns can be important for implementing sound biodiversity conservation programmes.     

THE OCCURRENCE AND STRUCTURE OF FLAGELLAR SCALES IN SOME FRESHWATER CRYPTOPHYTES1

Flagellar scales were found in seven out of eleven fresh-water cryptophytes investigated by shadowing whole cells. All scales examined were 140 to 170 nm in diameter and had a basic seven-sided rosette pattern with delicate interlacing. The results of this study indicate that flagellar scales are common in cryptophytes .     

A continental measure of urbanness predicts avian response to local urbanization

Understanding species-specific relationships with their environment is essential for ecology, biogeography and conservation biology. Moreover, understanding how these relationships change with spatial scale is critical to mitigating potential threats to biodiversity. But methods which measure inter-specific variation in response to environmental parameters that are also generalizable across multiple spatial scales are scarce. We used broad-scale avian citizen science data, over continental Australia, integrated with remotely-sensed products, to produce a measure of urban-tolerance for a given species at a continental-scale. We then compared these urban-tolerances to modelled responses to urbanization at a local-scale, based on systematic sampling within four small cities. For 49 species which had sufficient data for modelling, we found a significant relationship (R² = 0.51) between continental-scale urbanness and local-scale urbanness. We also found that relatively few citizen science observations (~250) are necessary for reliable estimates of continental-scale species-specific urban scores to predict local-scale response to urbanization. Our approach demonstrates the applicability of broad-scale citizen science data, contrasting both the spatial grain and extent of standard point-count surveys generally only conducted at small spatial scales. Continental-scale responses in Australia are representative of small-scale responses to urbanization among four small cities in Australia, suggesting that our method of producing species-specific urban scores is robust and may be generalized to other locations lacking appropriate data.