Determining adequate trapping effort and species richness using species accumulation curves for environmental impact assessments

Abstract Environmental impact assessments (EIA) require that the proponent indicates the potential impact that a development will have on the biodiversity of the area. As part of this assessment it is normal practice to inventory the vertebrate species in the area. We show here how species accumulation curves can be used as a tool by environmental consultants to indicate the adequacy of their trapping effort and predict species richness for a disturbance site. The shape of a species accumulation curve is influenced by the number of species in an assemblage and the proportional number of singletons (rarely caught species) in the survey sample. We provide guidelines for the number of individuals that need to be caught in a trapping program to achieve 80% and 90% of the species in a habitat, and we indicate how this number can be adjusted to accommodate variations in relative species abundance.     

Neotropical Copestylum (Diptera,Syrphidae) breeding in Agavaceae and Cactaceae including seven new species

We studied 42 species of saprophagous, Neotropical Copestylum (Diptera, Syrphidae) reared from decaying Cactaceae and Agavaceae. Thirty‐three species were reared during fieldwork in Bolivia, Costa Rica, Ecuador, Mexico, Peru, and Trinidad from 1998–2007. Nine species came from museum and private collections. Seven were new species. We describe these new species and the third stage larva and/or puparium and breeding sites of 40 species. Not described are two apparent species related to Copestylum apicale (Loew, 1866) reared from Cactaceae. Resolution of their status was beyond the scope of this paper but reference is made to their distinctive larval morphology. Based on early stage characters all reared species can be placed in ten species groups, all but three of which have been recognized previously on the basis of adult characters. A high level of congruence was found between adult and larval characters in terms of these species groups. Eight of the groups appear to be related closely and may represent a monophyletic lineage within Copestylum that has diversified in xeric habitats. Early stage morphology varied within and amongst groups but two trends in functional morphology are recognizable. One trend is towards feeding in watery decay and the other towards feeding in firmer decay. The latter trend is characterized by species that scoop food and use grinding mills in their head skeletons to break it up. They also have armoured thoraces with varying arrangements of sclerotized spicules or stiffened setae for gripping and protection during tunnelling, a short anal segment, and a short posterior breathing tube for protecting the openings. The former trend is characterized by species with opposite and contrasting features. They filter food and have well‐developed pre‐oral setal filters but they lack grinding mills or only have poorly developed grinding mills. They have reduced thoracic armature, elongate anal segments, and posterior breathing tubes which facilitates simultaneous feeding and respiration. Comparison with 23 Copestylum species reared from bromeliads (Bromeliaceae) suggests a common pattern of diversification in that species groups with the largest body sizes are more specialized.     

New Zealand phylogeography: evolution on a small continent

New Zealand has long been a conundrum to biogeographers, possessing as it does geophysical and biotic features characteristic of both an island and a continent. This schism is reflected in provocative debate among dispersalist, vicariance biogeographic and panbiogeographic schools. A strong history in biogeography has spawned many hypotheses, which have begun to be addressed by a flood of molecular analyses. The time is now ripe to synthesize these findings on a background of geological and ecological knowledge. It has become increasingly apparent that most of the biota of New Zealand has links with other southern lands (particularly Australia) that are much more recent than the breakup of Gondwana. A compilation of molecular phylogenetic analyses of ca 100 plant and animal groups reveals that only 10% of these are even plausibly of archaic origin dating to the vicariant splitting of Zealandia from Gondwana. Effects of lineage extinction and lack of good calibrations in many cases strongly suggest that the actual proportion is even lower, in keeping with extensive Oligocene inundation of Zealandia. A wide compilation of papers covering phylogeographic structuring of terrestrial, freshwater and marine species shows some patterns emerging. These include: east–west splits across the Southern Alps, east–west splits across North Island, north–south splits across South Island, star phylogenies of southern mountain isolates, spread from northern, central and southern areas of high endemism, and recent recolonization (postvolcanic and anthropogenic). Excepting the last of these, most of these patterns seem to date to late Pliocene, coinciding with the rapid uplift of the Southern Alps. The diversity of New Zealand geological processes (sinking, uplift, tilting, sea level change, erosion, volcanism, glaciation) has produced numerous patterns, making generalizations difficult. Many species maintain pre‐Pleistocene lineages, with phylogeographic structuring more similar to the Mediterranean region than northern Europe. This structure reflects the fact that glaciation was far from ubiquitous, despite the topography. Intriguingly, then, origins of the flora and fauna are island‐like, whereas phylogeographic structure often reflects continental geological processes.     

Do insects lose flight before they lose their wings? Population genetic structure in subalpine stoneflies

Wing reduction and flightlessness are common features of alpine and subalpine insects, and are typically interpreted as evolutionary adaptations to increase fecundity and promote local recruitment. Here, we assess the impact of wing reduction on dispersal in stoneflies (Plecoptera: Gripopterygidae: Zelandoperla ) in southern New Zealand. Specifically, we present comparative phylogeographic analyses (COI; H3) of strong-flying Zelandoperla decorata (144 individuals, 63 localities) vs. the co-distributed but weak-flying Zelandoperla fenestrata species group (186 individuals, 81 localities). The latter group exhibits a variety of morphotypes, ranging from fully winged to completely wingless. Consistent with its capacity for strong flight-mediated dispersal, Z .  decorata exhibited no substantial phylogeographic differentiation across its broad South Island range. Conversely the weak-flying fenestrata species group exhibited substantial genetic structure across both fine and broad geographic scales. Intriguingly, the variable degrees of wing development observed within the fenestrata species group had no apparent impact on levels of phylogeographic structure, which were high regardless of morphotype, suggesting that even fully winged specimens of this group do not fly. This finding implies that Zelandoperla flight loss occurs independently of wing loss, and might reflect underlying flight muscle reduction.     

Hydrological and biogeochemical controls on the timing and magnitude of nitrous oxide flux across an agricultural landscape

Anticipated increases in precipitation intensity due to climate change may affect hydrological controls on soil N₂O fluxes, resulting in a feedback between climate change and soil greenhouse gas emissions. We evaluated soil hydrologic controls on N₂O emissions during experimental water table fluctuations in large, intact soil columns amended with 100 kg ha^?1 KNO₃‐N. Soil columns were collected from three landscape positions that vary in hydrological and biogeochemical properties (N= 12 columns). We flooded columns from bottom to surface to simulate water table fluctuations that are typical for this site, and expected to increase given future climate change scenarios. After the soil was saturated to the surface, we allowed the columns to drain freely while monitoring volumetric soil water content, matric potential and N₂O emissions over 96 h. Across all landscape positions and replicate soil columns, there was a positive linear relationship between total soil N and the log of cumulative N₂O emissions (r²= 0.47; P= 0.013). Within individual soil columns, N₂O flux was a Gaussian function of water‐filled pore space (WFPS) during drainage (mean r²= 0.90). However, instantaneous maximum N₂O flux rates did not occur at a consistent WFPS, ranging from 63% to 98% WFPS across landscape positions and replicate soil columns. In contrast, instantaneous maximum N₂O flux rates occurred within a narrow range (?1.88 to ?4.48 kPa) of soil matric potential that approximated field capacity. The relatively consistent relationship between maximum N₂O flux rates and matric potential indicates that water filled pore size is an important factor affecting soil N₂O fluxes. These data demonstrate that matric potential is the strongest predictor of the timing of N₂O fluxes across soils that differ in texture, structure and bulk density.     

Climate-related, decadal-scale assemblage changes of seagrass-associated fishes in the northern Gulf of Mexico

Global temperatures are rising, and are expected to produce a poleward shift in the distribution of many organisms. We quantified changes in fish assemblages within seagrass meadows of the northern Gulf of Mexico (GOM) between the 1970s and 2006–2007, and observed changes consistent with this forecast. During 2006–2007 we sampled seagrass meadows using the same gears and methods previously employed by R. J. Livingston in coastal waters of northwest Florida throughout the 1970s. Comparisons between datasets revealed numerous additions to the fish fauna during 2006–2007 that were completely absent in the 1970s, including: Lutjanus synagris (lane snapper), Epinephelus morio (red grouper), Chaetodon ocellatus (spotfin butterflyfish), Mycteroperca sp (grouper, non gag), Centropristis philadelphica (rock sea bass), Fistularia tabacaria (bluespotted cornetfish), Ocyurus chrysurus (yellowtail snapper), Thalassoma bifasciatum (bluehead wrasse), Abudefduf saxatilis (sergeant major), Acanthuridae spp. (surgeonfishes) and Sparisoma viride (stoplight parrotfish). Several other species showed large increases in abundance during the interval between 1979 and 2006, including Mycteroperca microlepis (gag grouper, up ∼200 ×), Lutjanus griseus (gray snapper, up ∼105 ×), and Nicholsina usta (emerald parrotfish, up ∼22 ×). All of these are tropical or subtropical species that now make up a greater percentage of seagrass-associated fish assemblages in the northern GOM than in the past. Additionally, we observed regional increases in air and sea surface temperatures (> 3 °C) during the ∼30 years that separate Livingston's samples and ours that correlate with northern shifts in the distribution of warm-water fishes. Documenting these range shifts is a critical first step in investigating the consequences of global warming for endemic marine communities and fishery production in the northern GOM.     

Methanobactin-promoted dissolution of Cu-substituted borosilicate glass

Mineral weathering plays an important role in the global cycling of carbon and metals and there is an increasing realization that subsurface microbial activity may be a key factor controlling specific biogeochemical reactions and their rates. Methanobactin (mb) is an extracellular copper-binding compound excreted by methanotrophs to acquire copper for the regulation of methane oxidation. Bioavailable Cu regulates the expression and activity of pMMO vs. sMMO (particulate vs. soluble methane monooxygenase, respectively), key enzymes responsible for bacterial methane oxidation. In this study, we investigate the effect of mb on the dissolution of Cu-substituted borosilicate glass at low temperature and near neutral pH conditions, using batch dissolution experiments. Methanobactin promotes the dissolution of Cu-substituted glasses at rates faster than control experiments. Glasses with lower concentrations of copper (80 p.p.m.) or no copper are dissolved more rapidly by mb than those with more abundant copper (800 p.p.m.). Within the first 2 h of reaction, mb sorption onto glass surfaces limits mass transfer of Cu into solution, and at higher concentrations (100 µmol) of the ligand, inhibits dissolution rates of all glass formulations. These results suggest that both the concentration of mb in solution and the solid phase Cu concentration impact silicate weathering rates and related cycling of carbon in near-surface geological settings.     

Detection of spotted fever group Rickettsia spp. from bird ticks in the U.K.

Migratory birds are known to play a role in the long‐distance transportation of microorganisms. To investigate whether this is true for rickettsial agents, we undertook a study to characterize tick infestation in populations of the migratory passerine bird Riparia riparia (Passeriformes: Hirundinidae), the sand martin. A total of 194 birds were sampled and ticks removed from infested birds. The ticks were identified as female Ixodes lividus (Acari: Ixodidae) using standard morphological and molecular techniques. Tick DNA was assayed to detect Rickettsia spp. using polymerase chain reaction and DNA was sequenced for species identification. A single Rickettsia spp. was detected in 100% of the ticks and was designated Rickettsia sp. IXLI1. Partial sequences of 17‐kDa and ompA genes showed greatest similarity to Rickettsia sp. TCM1, an aetiological agent of Japanese spotted fever‐like illness, previously described in Thailand. Phylogenetic analysis showed that Rickettsia sp. IXLI1 fitted neatly into a group containing strains Rickettsia japonica, Rickettsia sp. strain Davousti and Rickettsia heilongjiangensis. In conclusion, this research shows that U.K. migratory passerine birds host ticks infected with Rickettsia species and contribute to the geographic distribution of spotted fever rickettsial agents.     

Natural infection with raspberry bushy dwarf virus (RBDV) of the putatively RBDV-resistant red raspberry cultivar Glen Moy, and the demonstration that it does not contain the RBDV resistance gene, Bu

When released to commerce in 1981, the red raspberry cv. Glen Moy was reported to be immune to the Scottish type isolate of raspberry bushy dwarf virus (RBDV-D200). Field observations of this cultivar in localities where RBDV was prevalent tended to support this claim of its resistance, but in the past 6–10 yr, RBDV infection has been reported in this cultivar in Australasia, USA and in several commercial crops in England. Therefore, experiments were made to investigate the reason(s) for this apparent anomaly using RBDV-infected material, putatively of cv. Glen Moy, from two locations in southern England and one each from Australia, New Zealand (NZ) and the USA. Genetic fingerprinting of genomic DNA from samples of these five RBDV-infected raspberry sources confirmed their identity as cv. Glen Moy. Comparisons of some serological and genomic properties of the five Glen Moy RBDV isolates indicated that, whilst they shared many properties with previously well characterised isolates of this virus, they were distinguishable from them. Characterisation of the isolate from NZ maintained in raspberry showed that it did not have a Rubus host range characteristic of resistance-breaking (RB) isolates, indicating that for this location, and probably also for those of Australia and the USA, RB isolates were not the cause of infection in cv. Glen Moy. When virus-tested plants of cv. Glen Moy and 45 progeny seedlings from the cross between cv. Glen Moy and the RBDV-susceptible cv. Autumn Bliss were graft inoculated with RBDV-D200, all grafted plants became infected indicating that cv. Glen Moy does not contain the RBDV resistance gene, Bu. Possible reasons for the previously reported resistance of cv. Glen Moy to RBDV are discussed.