The status of the world's land and marine mammals: diversity, threat, and knowledge

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action.     

Seasat scatterometer: results of the gulf of alaska workshop

The Seasat microwave scatterometer was designed to measure, globally and in nearly all weather, wind speed to an accuracy of +/- 2 meters per second and wind direction to +/- 20 degrees in two swaths 500 kilometers wide on either side of the spacecraft. For two operating modes in rain-free conditions, a limited number of comparisons to high-quality surface truth indicates that these specifications may have been met.     

Development and growth characteristics of Caucasian and white clover seedlings, compared with perennial ryegrass

Seedling competition for resources during establishment affects the potential success of individual species within a pasture. Germination, emergence and leaf expansion are key characteristics that contribute to the competitive ability of species. In this study, development and growth characteristics of Caucasian clover, white clover and perennial ryegrass (PRG) seedlings were quantified. A base temperature of <4°C and an optimum temperature of ～27°C were found for development in each species. Thermal time (Tt) requirements for 75% of final germination were lower for Caucasian clover (46°C d) and white clover (40°C d) than for PRG (76°C d), but Tt requirements for 50% of final emergence were similar (～110°C d). The phyllochron (°C d leaf^?1) for primary stem leaves was slower for Caucasian clover (109°C d) than for white clover (94°C d) and PRG (101°C d). Appearance of the first PRG tiller, which indicates the initiation of secondary leaf development, occurred after 373°C d, compared with 532°C d for the first white clover stolon. Caucasian clover crown shoots did not develop until >1180°C d. Consequently, white clover and PRG had more leaves (～15 plant^?1) and faster shoot relative growth rates (～0·062 mg mg^?1 d^?1) than Caucasian clover (5 leaves plant^?1, 0·049 mg mg^?1 d^?1).     

Photosynthetic light use efficiency of three biomes across an east–west continental-scale transect in Canada

Light use efficiency (LUE) is used widely in scaling and modeling contexts. However, the variation and biophysical controls on LUE remain poorly documented. Networks of eddy covariance (EC) towers offer an opportunity to quantify _g, the ratio of P, gross primary productivity, to Q_a, absorbed photosynthetically active radiation (PAR), across climate zones and vegetation types. Using data from the Fluxnet Canada Research Network (n = 24 sites) in 2004, we examined the relationship between daily and yearly _g, driving variables, and site characteristics on a site-specific and plant functional type (PFT) basis using tree regression and linear regression. Data were available for three biomes: grassland, forest, and wetland. Yearly _g values ranged from 0.1 to 3.6 g C MJ⁻¹ Q_a overall. Daily _g was highest in the grassland (daily median ± interquartile range: 3.68 ± 1.98 g C MJ⁻¹ Q_a), intermediate in the forested biome (0.84 ± 0.82 g C MJ⁻¹ Q_a), and lowest for the wetlands (0.65 ± 0.54 g C MJ⁻¹ Q_a). The most important biophysical controls were light and temperature, to the exclusion of water-related variables: a homogeneity of slopes model explained c. 75% of the variation in daily _g. For a subset of sites with diffuse PAR data, the ratio of diffuse to total PAR, a proxy for cloudiness, was a key predictor. On the yearly time scale, _g was related to leaf area index and mean annual temperature. Aggregating to PFTs did not show functional convergence within any PFT except for the three wetland sites and the Picea mariana toposequence at the daily time step, and when using the Köppen climate classification on a yearly time step. The general lack of conservative daily _g behavior within PFTs suggests that PFT-based parameterizations are inappropriate, especially when applied on shorter temporal scales.     

Presumed lupus erythematosus cells identified in bronchoalveolar lavage fluid from a Mexican Hairless dog

A neutered male Mexican Hairless dog was presented for generalized weight loss and weakness. Initial laboratory testing and diagnostic imaging revealed thrombocytopenia and an interstitial to miliary lung pattern affecting all lung fields. Mild joint effusion was found on physical examination affecting the stifle, tarsal, carpal, and elbow joints. Examination of synovial fluid demonstrated an inflammatory polyarthropathy in 3 joints. Cytocentrifuged and direct preparations of the bronchoalveolar lavage (BAL) fluid sample were made and cells consistent with lupus erythematosus (LE) cells and ragocytes were found. Based on these findings, the anti‐nuclear antibody (ANA) titer was determined as 1:640. A clinical diagnosis of systemic LE was made based on the satisfaction of 2 major criteria (thrombocytopenia and inflammatory polyarthritis), 4 minor criteria (central nervous system signs, lymphadenopathy, fever of unknown origin, and pleuritis), positive ANA titer, and the identification of presumed LE cells in BAL fluid. This case report highlights a novel finding of LE cells in respiratory secretions and provides a review of diagnostic criteria of systemic LE.     

Soil CO<Subscript>2</Subscript>, CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O emissions from production fields with planted and remnant hedgerows in the Fraser River Delta of British Columbia

Planting hedgerows on farm field edges can help mitigate greenhouse gas (GHG) emissions from agricultural landscapes by sequestering carbon (C) in woody biomass and in soil. Sequestration rates however, must be assessed in terms of their overall global warming potential (GWP) which must also consider GHG emissions. The objectives of this study were to (1) compare carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) emissions from two types of hedgerows and adjacent annual agricultural production fields, and 2) better understand how climate, soil properties and plant species configurations affect hedgerow GHG emissions. At eight study sites in the lower Fraser River delta of British Columbia, we measured emissions from soil in both planted (P-Hedgerow) and remnant hedgerows (R-Hedgerow), as well as in adjacent annual crop production fields over 1 year using a closed-static chamber method. CO₂ emissions were 59 % higher in P-Hedgerow than R-Hedgerow, yet there were no significant differences of relative emissions of CH₄ and N₂O. The environmental variables that explained the variation in emissions differed for the three GHGs. CO₂ emissions were significantly correlated with soil temperature. CH₄ and N₂O and emissions were marginally significantly correlated with soil organic carbon (SOC) and soil water-filled pore space (WFPS), respectively. Emissions were not significantly correlated with hedgerow plant species diversity. While hedgerows sequester carbon in their woody biomass, we demonstrated that it is critical to measure hedgerow emissions to accurately ascertain their overall GHG mitigation potential. Our results show that there are no CO₂e emission differences between the management options that plant new diverse hedgerows or conserve existing hedgerows.     

Long-term P fertilisation of pasture soil did not increase soil organic matter stocks but increased microbial biomass and activity

The soil organic matter (OM) content of soils in a long-term fertiliser field trial (Winchmore, New Zealand) are similar (P > 0.05) despite >60 years application of different phosphorus (P) rates. As the net primary productivity increased with P addition, greater losses of carbon (C) occur concomitantly with increased P fertility. Several hypotheses have been proposed to explain the mechanisms, including C leaching, increased earthworm activity or elevated rates of microbial activity. In this study, we found support for both direct and secondary effects of soil P on soil C through impacts on the soil microbial community. Microbial biomass, inferred through quantification of hot water extractable C, increased with soil P status and decreased with C/P ratio (P < 0.001). However, the microbial biomass had no relationship with soil organic C content (P = 0.485). Mineralisation of C substrates added to soil also increased with soil P status (total P, R ² = 0.84; P < 0.001). These results indicated potential conditioning of the microbial community for rapid C cycling. Utilisation of different C compounds was clustered by cophenetic similarity; a distinct group of ten carbon compounds was identified for which rates of mineralisation were strongly associated with soil P status and microbial biomass. However, this alteration of microbial community size and activity was not reflected in abundances of selected oligotrophic and copiotrophic taxa. As such, the alteration may be due to changes in the abundances of all taxa, i.e. a general community response.