The effect of ocean acidification and temperature on the fertilization and embryonic development of the Sydney rock oyster Saccostrea glomerata (Gould 1850)

This study investigated the synergistic effects of ocean acidification (caused by elevations in the partial pressure of carbon dioxide pCO₂) and temperature on the fertilization and embryonic development of the economically and ecologically important Sydney rock oyster, Saccostrea glomerata (Gould 1850). As pCO₂ increased, fertilization significantly decreased. The temperature of 26 °C was the optimum temperature for fertilization, as temperature increased and decreased from this optimum, fertilization decreased. There was also an effect of pCO₂ and temperature on embryonic development. Generally as pCO₂ increased, the percentage and size of D‐veligers decreased and the percentage of D‐veligers that were abnormal increased. The optimum temperature was 26 °C and embryonic development decreased at temperatures that were above and below this temperature. Abnormality of D‐veligers was greatest at 1000 ppm and 18 and 30 °C (≥90%) and least at 375 ppm and 26 °C (≤4%). Finally prolonged exposure of elevated pCO₂ and temperature across early developmental stages led to fewer D‐veligers, more abnormality and smaller sizes in elevated CO₂ environments and may lead to lethal effects at suboptimal temperatures. Embryos that were exposed to the pCO₂ and temperature treatments for fertilization and embryonic development had fewer D‐veligers, greater percentage of abnormality and reduced size than embryos that were exposed to the treatments for embryonic development only. Further at the elevated temperature of 30 °C and 750–1000 ppm, there was no embryonic development. The results of this study suggest that predicted changes in ocean acidification and temperature over the next century may have severe implications for the distribution and abundance of S. glomerata as well as possible implications for the reproduction and development of other marine invertebrates.     

Strong links between teleconnections and ecosystem exchange found at a Pacific Northwest old-growth forest from flux tower and MODIS EVI data

Variability in three Pacific teleconnection patterns are examined to see if net carbon exchange at a low‐elevation, old‐growth forest is affected by climatic changes associated with these periodicities. Examined are the Pacific Decadal Oscillation (PDO), Pacific/North American Oscillation (PNA) and El Niño‐Southern Oscillation (ENSO). We use 9 years of eddy covariance CO₂, H₂O and energy fluxes measured at the Wind River AmeriFlux site, Washington, USA and 8 years of tower‐pixel remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) to address this question. We compute a new Composite Climate Index (CCI) based on the three Pacific Oscillations to divide the measurement period into positive‐ (2003 and 2005), negative‐ (1999 and 2000) and neutral‐phase climate years (2001, 2002, 2004, 2006 and 2007). The forest transitioned from an annual net carbon sink (NEP=+217 g C m^?2 yr^?1, 1999) to a source (NEP=?100 g C m^?2 yr^?1, 2003) during two dominant teleconnection patterns. Net ecosystem productivity (NEP), water use efficiency (WUE) and light use efficiency (LUE) were significantly different (P<0.01) during positive (NEP=?0.27 g C m^?2 day^?1, WUE=4.1 mg C g^?1 H₂O, LUE=0.94 g C MJ^?1) and negative (NEP=+0.37 g C m^?2 day^?1, WUE=3.4 mg C g^?1 H₂O, LUE=0.83 g C MJ^?1) climate phases. The CCI was linked to variability in the MODIS Enhanced Vegetation Index (EVI) but not to MODIS Fraction of absorbed Photosynthetically Active Radiation (FPAR). EVI was highest during negative climate phases (1999 and 2000) and was positively correlated with NEP and showed potential for using MODIS to estimate teleconnection‐driven anomalies in ecosystem CO₂ exchange in old‐growth forests. This work suggests that any increase in the strength or frequency of ENSO coinciding with in‐phase, low frequency Pacific oscillations (PDO and PNA) will likely increase CO₂ uptake variability in Pacific Northwest conifer forests.     

Private Lands Programs and Lessons Learned in Illinois

ABSTRACT State wildlife agencies commonly offer private landowners cost-share and technical assistance to improve habitat, but the cost-effectiveness and long-term outcomes of these efforts are rarely evaluated. In 1998, we began a 3-part, statewide evaluation of the Illinois Department of Natural Resources’ (IDNR; USA) Private Land Wildlife Habitat Management Program (hereafter the program) as it functioned from 1986 to 1996. We sent a mail-back questionnaire to IDNR biologists to collect information on their perceptions of the program. We sent a separate mail-back questionnaire to private landholders who participated in the program to ascertain their demographic profile, motivations for participation, and attitudes regarding the program. We also conducted on-site evaluations of private properties that were managed under the guidance of the program. We conducted our study to 1) assess if the program effectively assisted participants in establishing and maintaining wildlife habitat, and 2) determine factors associated with optimal management of wildlife habitat on private lands to refine the program and improve effectiveness. We found significant differences between participants in their land use priorities and motivations for managing wildlife and in the resources available to participants to establish and maintain habitat. Our results indicate that although financial incentives may increase participation in private lands initiatives, improving technical and material assistance to landholders is essential for maintaining quality wildlife habitat over the long-term.     

Effectiveness of Vaginal-Implant Transmitters for Locating Elk Parturition Sites

ABSTRACT We assessed success of vaginal implant transmitters (VITs), deployed in 198 elk (Cervus elaphus nelsoni), in locating elk calving sites in western Wyoming, USA, in 2006–2007. We identified 60.3% of expelled VIT locations as definite or probable event markers and an additional 21.8% as possible event markers. Failure rate for VITs was 10.6%, and we found an additional 7.3% in improbable or impossible parturition sites. Vaginal implant transmitters were effective in locating calving and abortion sites and will facilitate definition of parturition habitat selection and parturition ranges of specific subpopulations.     

The so‐called primitive genera of Genisteae (Fabaceae): systematic and phyletic considerations based on karyological data

A karyological analysis of the so‐called primitive genera of Genisteae has shown that they have a relatively homogeneous chromosome complement: all species tend to have a somatic chromosome number 2n = 48, which can increase to 2n = 52, presumably as a result of hyperaneuploidy. Karyological data suggest that Argyrocytisus, Cytisophyllum and Petteria may be considered as distinct genera rather than being assigned to Cytisus, with 2n = 52 for the first of these and 2n = 50 for the other two genera. They may be interpreted as relict monotypic genera as a result of the presence of a stabilized aneuploidy. Karyological characters exclude a recent origin of Genisteae from Thermopsideae. On the contrary, they are consistent with the hypothesis that Genisteae and Thermopsideae are independently derived from a basic papilionoid stock, of which present day Sophoreae are the remainder. At least two lines would lead from Sophoreae to the taxa of the ‘genistoid alliance’, one to Thermopsideae and the other ‘podalyrioid alliances’ (Podalyrieae and Mirbelieae), with the prevailing basic number of x = 9, and the other to Genisteae, with a basic number of x = 12 persisting in some present day genera, including Cytisus s.l. From this lineage, a wide range of secondary basic numbers has been formed, mostly by descending aneuploidy. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 232–248.     

Regional examination shows potential for native feedstock options for cellulosic biofuel production

Kentucky, as with many regions around the globe, has a relatively long growing season with significant rainfall that could produce sizeable quantities of perennial herbaceous and woody biomass on land that does not compete with food crops. Additionally, there are limited options for renewable power production from low carbon sources such as solar-photovoltaic, wind and hydroelectric. Recent studies have shown that producing renewable energy from perennial cellulosic crops, as opposed to starch-based biofuel crops, will have a carbon-mitigating outcome. Currently, there is a lack of data regarding regionally suitable genotypes. Herein, we establish baseline values for multiple entry selections of three native C4 grass species, switchgrass (SW) ( Panicum virgatum L.), eastern gamagrass (EG) (Trispicum dactyloides L. ) and big bluestem (BB) (Andropogon gerardii Vitman ) . Yield potential examined over 7 years showed that environment, species and entries had a significant impact on yield, but EG had higher total yield over the duration of the study. Cellulosic biofuel potential was examined by measurement of saccharification efficiency, relative lignocellulosic energy density, cellulose content and lignin content during three growing seasons. EG had significantly higher digestibility rate than SW and BB. Underlying this was a negative correlation between lignification and saccharification efficiency. However, higher lignin content and higher cellulose content among SW entries resulted in higher energy density relative to EG and BB. These data reveal that locally bred EG varieties were most suited to cellulosic ethanol production under the growing conditions of central Kentucky, USA, compared with SW and BB and suggest the importance of regional examination.     

Population decline is accompanied by loss of genetic diversity in the Lesser Grey Shrike Lanius minor

The Lesser Grey Shrike has suffered successive declines in population size and a marked contraction of its breeding range since the early 20th century, largely because of long‐term agricultural intensification. This has resulted in a severely fragmented distribution in Western Europe, with isolated breeding nuclei in Spain, France and Italy and a more continuous distribution in Eastern Europe and Asia. Using a combination of nuclear and mitochondrial markers, we assessed the genetic structure and diversity of Lesser Grey Shrike populations from Western Europe, Central Europe and Asia. There was significant genetic differentiation among three major regional groups, one European and two Asian. Genetic diversity measures were lowest in the smallest and most marginal Spanish population. Limited genetic diversity, combined with rapid population decline, suggests the Spanish population may face extinction in the near future.     

Can limited dispersal or biotic interaction explain the declining abundance of the whelk,Morula marginalba,at the edge of its range?

The southern range limit of the planktotrophic, intertidal whelk, Morula marginalba, occurs immediately to the north of the south‐east Australian biogeographical barrier and we predict that its range may be limited by dispersal and biotic interactions. The barrier includes several hundred kilometers without suitable habitat and is the convergence zone of major ocean currents. Within the barrier region, along‐shore larval transport is expected to be erratic, with water moving offshore to form long‐lived eddies. Through comparison of central and range edge populations, we test for evidence of recruitment limitation and interspecific competition with the whelk, Haustrum vinosum, which occurs sympatrically at the range edge. We found similar levels of recruitment and allozyme genetic variation within centre and edge populations where H. vinosum was absent, implying that populations are strongly interconnected. Nevertheless, recruitment and abundance of M. marginalba were lower at its extreme range limit, where it occurs with H. vinosum. Indeed, we detected significant inverse correlations between the abundance of these species, although their habitat use was similar and they consumed similar prey. These lines of evidence suggest a restricted recruitment across the barrier limits the range of M. marginalba but emphasize that multiple factors may act to set species range limits. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 849–862.     

Waardenburg综合征Ⅱ型患者MITF基因突变分析

Waardenburg综合征(WS)是临床上常见的常染色体显性遗传性耳聋综合征, MITF基因突变与部分Waardenburg 综合征Ⅱ型(WS2)病例的发病有关。MITF属于碱性螺旋-环-螺旋亮氨酸拉链转录因子家族, 能调节酪氨酸酶基因, 参与黑色素细胞的分化。文章报道了1个携带MITF基因点突变的3代Waardenburg综合征Ⅱ型中国家系。先证者表现为先天性重度感音神经性聋、虹膜异色、面部雀斑; 其他家系成员除一名仅表现为先天性耳聋外, 均表现为颜面、上肢雀斑和/或早白发。患者可检测到c.639delA杂合突变, 该突变在MITF基因第7外显子上产生了终止密码子(p.I220X), 突变产生的截短的MITF蛋白没有DNA结合活性。该突变是WS2病例中第3个位于MITF第7外显子的突变, 尚未见报道。该突变与已报道的位于第7外显子其他两个突变仅相差1个碱基, 氨基酸改变十分相似, 但在表型上有显著差别, 提示遗传背景对WS临床表型有重要影响。     

Determining uptake of 'non-labile' soil cadmium by Thlaspi caerulescens using isotopic dilution techniques

We assessed the ability of several populations of the metal-hyperaccumulator species, Thlaspi caerulescens , to mobilize non-labile cadmium in soils historically contaminated by Pb/Zn mine spoil or sewage sludge. Radio- labile Cd was determined chemically as an ' E -value', [Cd _E ], and biologically as an ' L -value', [Cd _L ]. For comparison, chloride-extractable Cd, [Cd_chlor], was also determined using 1 M CaCl₂ as a single-step soil extractant. Values of [Cd _L ] were measured for six populations of T. caerulescens that varied substantially in their ability to assimilate soil Cd, and a non-accumulator species with a similar growth habit, Lepidium heterophyllum . Seeds were sown in soil spiked with ¹⁰⁹Cd and grown for 9–12 wk in a controlled environment room. Values of [Cd _L ] were determined from the specific activity of ¹⁰⁹Cd and concentration of Cd in the plant leaves. For the six soils studied, [Cd _E ] ranged from 4.9 to 49% of total soil Cd [Cd_T]. Values of [Cd _L ] were, in general, in close agreement with both [Cd _E ] and [Cd_chlor] and substantially less than [Cd_T]. However, [Cd _L ] showed no correlation with the concentration of Cd in plant tissue, [Cd_shoot]. This suggests that, in the soils studied, T. caerulescens did not mobilize non-labile soil Cd by producing root exudates or altering rhizosphere pH. The results imply that there may be significant restrictions to metal bioavailability, even to hyperaccumulator species, in heavily contaminated soils in which a large proportion of the metal may be present in 'non-labile' forms.