The use of artificial nest sites erected for starlings in Canterbury,New Zealand

The erection of suitable nest boxes in Canterbury led to local increases in the population of starlings (Sturnus v. vulgaris L), which were enhanced in successive years by the tendency of adults to return to breed in the same box. Boxes with circular entrance holes placed highest in hedgerows were favoured over those with rectangular entrances, those placed lower in hedgerows, or those on either fences or barns. Intraspecific competition for suitable artificial sites occurred frequently, and accounted for 9.7% of all egg and nestling losses. House sparrows (Passer domesticus L) also bred in artificial sites, particularly those previously used by starlings, and local increases in house sparrow populations seemed likely.     

Phylogenetic beta diversity reveals historical effects in the assemblage of the tree floras of the Ryukyu Archipelago

Quantifying the roles of historical versus contemporary constraints in determining species diversity is a central issue in island biogeography, and the phylogenetic beta diversity between islands is an essential measure specifying the influence of historical barriers on insular assemblages. In this study, using phylogenetic information for 513 tree species on 26 islands in the subtropical Ryukyu Archipelago, phylogenetic beta diversity between islands was calculated, and effects of historical factors (gaps as surrogate measures of historical barriers) and current ones (distance, area and elevation) on the phylogenetic structure of tree assemblages were examined. The pattern of phylogenetic beta diversity demonstrated that the Tokara Gap and geographical distance were consistently important for characterizing tree assemblages in the Ryukyus relative to other historical and current factors, which suggests that the Tokara Gap and distance‐limited dispersal from the two adjacent source islands have left a deep imprint on the phylogenetic structure of the current tree flora of the islands.     

Recruitment patterns in Antarctic Peninsula shelf sediments: evidence of decoupling from seasonal phytodetritus pulses

Summer phytoplankton blooms on the West Antarctic Peninsula (WAP) shelf result in episodic deposition of labile food material for benthic detritivores. This summer deposition is thought to enhance benthic recruitment of macro- and megafauna. To explore seasonality in benthic recruitment, juvenile invertebrates (>100 μm) were collected in a seasonal time series at three stations on the WAP continental shelf. 4,098 juveniles were collected (average densities 2,000–7,000 m⁻²), with polychaetes dominant (2,581 individuals). The majority of polychaetes showed evidence of enhanced recruitment prior to the summer bloom, although patterns varied across stations. Additional taxa showed recruitment peaks in summer, but again, patterns varied among stations. Based on observed patterns, polychaete taxa are classified as “seasonal”, “marginally seasonal”, and “non-seasonal” recruiters, with the latter two patterns predominating. The year-round presence of small juveniles in most taxa suggests that recruitment occurs continuously, with periodic enhancement. Year-round recruitment is consistent with the presence of a persistent “food bank” of labile organic material in WAP shelf sediments, allowing recruitment to be largely decoupled from seasonal bloom dynamics.     

Ecology matters: Atlantic-Mediterranean disjunction in the sand-dune shrub Armeria pungens (Plumbaginaceae)

Inferring the evolutionary history of Mediterranean plant lineages from current genetic, distributional and taxonomic patterns is complex because of a number of palaeoclimatic and geological interconnected factors together with landscape heterogeneity and human influence. Therefore, choosing spatially simplified systems as study groups is a suitable approach. An amplified fragment length polymorphism (AFLP) study using two restriction enzyme combinations (EcoRI/MseI and KpnI/MseI) was carried out to estimate the structure of genetic variation throughout the range of Armeria pungens. This species has a West Iberian-Corso/Sardinian disjunct distribution on coastal sand-dune ecosystems. Bayesian, amova and genetic distance analyses of the AFLP data revealed the same distinguishable genetic groups, which do not match the main geographical disjunction. Corso-Sardinian populations were found to be genetically closer to southwest Portuguese than to those from the Gulf of Cadiz (the closest geographically). Eastwards long-distance dispersal is therefore invoked to explain this geographical disjunction. A GIS analysis based on bioclimatic envelope modelling aiming to characterize the current locations of A. pungens found strong similarities between the Portugal and Corsica-Sardinia sites and less so between these areas and the Gulf of Cadiz. This coincident pattern between AFLP and climatic data suggests that the geographical disjunction is better explained by climatic factors than by the likeliness of a stochastic dispersal event. Such a combined phylogeographical-GIS modelling approach proves to be enlightening in reconstructing the evolutionary history of plant species.     

Phylogeography of Rhinichthys cataractae (Teleostei: Cyprinidae): pre‐glacial colonization across the Continental Divide and Pleistocene diversification within the Rio Grande drainage

The longnose dace, Rhinichthys cataractae, is a primary freshwater fish inhabiting riffle habitats in small headwater rivers and streams across the North American continent, including drainages east and west of the Continental Divide. The mitochondrially encoded cytochrome b gene (1140 bp) and 2298–2346 bp of the nuclear‐encoded genes S7 and RAG1 were obtained from 87 individuals of R. cataractae (collected from 17 sites throughout its range) and from several close relatives. Phylogenetic analyses recovered a monophyletic R. cataractae species‐group that contained Rhinichthys evermanni, Rhinichthys sp. ‘Millicoma dace’, and a non‐exclusive R. cataractae. Within the R. cataractae species‐group, two well‐supported lineages were identified, including a western lineage (containing R. evermanni, R. sp. ‘Millicoma dace’ and individuals of R. cataractae from Pacific slope drainages) and an eastern lineage (containing individuals of R. cataractae from Arctic, Atlantic, and Gulf slope drainages). Within the eastern lineage of R. cataractae, two well‐supported groups were recovered: a south‐eastern group, containing individuals from the Atlantic slope, southern tributaries to the Mississippi River, and the Rio Grande drainage; and a north‐eastern group, containing individuals from the Arctic slope and northern tributaries to the Mississippi River. Estimates of the timing of divergence within the R. cataractae species‐group, combined with ancestral area‐reconstruction methods, indicate a separation between the eastern and western lineages during the Pliocene to early‐Pleistocene, with a direction of colonization from the west of the Continental Divide eastward. Within the southern portion of its range, R. cataractae likely entered the Rio Grande drainage during the Pleistocene via stream capture events between the Arkansas River (Mississippi River drainage) and headwaters of the Rio Grande. A close relationship between populations of R. cataractae in the Rio Grande drainage and the adjacent Canadian River (Mississippi River drainage) is consistent with hypothesized stream capture events between the Pecos (Rio Grande drainage) and Canadian rivers during the late‐Pleistocene. The population of R. cataractae in the lower Rio Grande may have become separated from other populations in the Rio Grande drainage (upper Rio Grande and Pecos River) and Canadian River during the late‐Pleistocene, well before initiation of recent and significant anthropogenic disturbance within the Rio Grande drainage. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 317–333.     

Plant speciation in continental island floras as exemplified by Nigella in the Aegean Archipelago

Continental shelf island systems, created by rising sea levels, provide a premier setting for studying the effects of geographical isolation on non-adaptive radiation and allopatric speciation brought about by genetic drift. The Aegean Archipelago forms a highly fragmented complex of mostly continental shelf islands that have become disconnected from each other and the mainland in relatively recent geological times (ca <5.2Ma). These ecologically fairly homogenous islands thus provide a suitable biogeographic context for assessing the relative influences of past range fragmentation, colonization, gene flow and drift on taxon diversification. Indeed, recent molecular biogeographic studies on the Aegean Nigella arvensis complex, combining phylogenetic, phylogeographic and population level approaches, exemplify the importance of allopatry and genetic drift coupled with restricted gene flow in driving plant speciation in this continental archipelago at different temporal and spatial scales. While the recent (Late Pleistocene) radiation of Aegean Nigella, as well as possible instances of incipient speciation (in the Cyclades), is shown to be strongly conditioned by (palaeo)geographic factors (including changes in sea level), shifts in breeding system (selfing) and associated isolating mechanisms have also contributed to this radiation. By contrast, founder event speciation has probably played only a minor role, perhaps reflecting a migratory situation typical for continental archipelagos characterized by niche pre-emption because of a long established resident flora. Overall, surveys of neutral molecular markers in Aegean Nigella have so far revealed population genetic processes that conform remarkably well to predictions raised by genetic drift theory. The challenge is now to gain more direct insights into the relative importance of the role of genetic drift, as opposed to natural selection, in the phenotypic and reproductive divergence among these Aegean plant species.     

Cooling-driven climate change at 12–11 Ma: Multiproxy records from a long fluviolacustrine sequence at Guyuan, Ningxia, China

To explore the evolution of climate through the Miocene, especially during the Middle Miocene climate transition, multiproxy continental records were analyzed by susceptibility (SUS), lightness (L), total inorganic carbon (TIC) and total organic carbon (TOC) content from the 2900-m-thick fluviolacustrine sediment sequence at Guyuan, Ningxia, China and compared with the redness (a) and the pollen humidity indices from the same section. The published Miocene records of sedimentation rate, sediment grain size, biota turnover, and palaeoproductivity from other regions were also compiled and compared. Results show that multiproxies of the Sikouzi section have changed substantially since 12–11 Ma ago. SUS, L and TIC have increased while a, TOC and the pollen humidity index decreased, all implying that the palaeoclimate in the study area has got cooler and drier since that time.This climate change also left imprints in many other regions, probably resulting from global cooling and the development of the East Antarctic Ice Sheet since about 14 Ma. Several positive feedback mechanisms are proposed to have effectively modulated and magnified the Mid-Miocene global cooling, including vegetation change, greenhouse gas (atmospheric CO₂ and water vapor) fluctuations. They led to the strengthing of ocean and atmospheric circulation, significant lowering of sea level and increasing aridification over the globe, especially in middle-high latitudes. Since 12–11 Ma ago, a continuously cooler and drier climate may have caused the substantial intensification of physical weathering and exhumation on the earth's surface, the increased sediment accumulation rates on the land and in the sea, and the inception of productivity increase in the oceans. Nevertheless, when and where these mechanisms operated and how they were tied to each other remain ambiguous, deserving further investigation.     

First record of Cynoscion regalis (Pisces,Sciaenidae) in Portuguese continental waters

The occurrence of Cynoscion regalis in Portuguese continental waters is reported for the first time, with six specimens collected in 2015 from three areas: Tagus Estuary, Sado Estuary and Praia da Vieira (central‐west coast). Analyses of morphometric and meristic characteristics confirmed all six specimens as C. regalis; further validation was obtained by sequencing a 675 bp region of the mitochondrial cytochrome c oxidase I gene. These records constitute a range extension of C. regalis into the southern north‐east Atlantic Ocean.     

How well documented is Australia's flora? Understanding spatial bias in vouchered plant specimens

Massive digitization of natural history collections (NHC) has opened the door for researchers to conduct inferential studies on the collection of biological diversity across space and time. The widespread use of NHCs in scientific research makes it essential to characterize potential sources of spatial bias. In this study, we assessed spatial patterns in records from the Australian Virtual Herbarium (AVH), based on >3 000 000 vouchered specimens of around 21 000 native plant species. The AVH is the main database for describing Australia's flora, and identifying its limitations is of paramount interest for the validity of conservation and environmental studies. We characterized how sampling effort is distributed across each Interim Bioregion of Australia (IBRA), then asked: (i) How complete are species inventories for each bioregion? We define completeness (C) as the ratio of observed to estimated species richness, using the Chao 1 estimator, (ii) How is sampling effort related to a commonly used Human Influence Index (HII)? and (iii) What is the probability that additional collections would result in the identification of previously unrecorded species in each bioregion? Sampling effort across bioregions is unequal, which partially reflects the collecting behaviour of naturalists in relation to species richness patterns. The density of records in bioregions ranges from 0.02–8.37 km^?2. At the bioregional scale, completeness is generally high with 79% of bioregions estimated to have records for at least 80% of their species. Completeness is partly explained by sampling effort (r = 0.43, p = 0.01), although some bioregions (e.g. Northern Kimberley and Burt Plain) have high completeness yet relatively low sampling effort. The inventory of Hampton, however, is substantially less complete than other bioregions (C = 0.66). Bioregions with high HII consistently have high completeness, while regions with low HII span the full range of completeness values. We calculated that an additional specimen collected from a bioregion has a 0.33% (Wet Tropics) to 11.7% (Arnhem Coast) probability of representing a new species for that region. Our assessment can assist with directing future systematic survey efforts by identifying bioregions where additional surveying may result in the greatest return, in terms of increasing knowledge of species richness and diversity.     

东海陆缘(浙南段)晚第四纪硅藻的发现及古环境分析

东海陆缘(浙南段)温州沿海以往第四纪沉积已开展了一些研究,见有丰富的有孔虫、孢粉等生物化石,但未发现硅藻。本项研究在温州CH6井、台州CH5井岩心中发现了大量硅藻化石,本文以温州CH6井丰富的硅藻化石为依据,建立了晚第四纪硅藻组合序列,划分为12个硅藻带,并恢复其古环境演替,根据四个AMS ^14C年代数据,其时代属早、中全新世。