Changes in carbon and nitrogen fractions of graminaceous straws after burning

Summary Changes in the carbon (C) and nitrogen (N) fractions of graminaceous straws were measured after their combustion under both laboratory and open-air conditions. Volatilization of C and N increased with increasing combustion, and losses exceeded 90% when combustion was nearly complete. The small proportion of total N already present in the inorganic form in straw was not increased during the ashing process.Burning of plant residues decreases the amount of organic microbial substrates returned to the soil, and hence directly affects soil biological processes. In addition, the volatile loss of nutrients occurring during the burning of vegetation must be considered in the long-term nutrient economy of ecosystems, and hence in the full evaluation of fire as a management tool.     

Effect of torpor on the water economy of an arid-zone marsupial,the stripe-faced dunnart (<Emphasis Type="Italic">Sminthopsis macroura</Emphasis>)

Metabolic rate and evaporative water loss (EWL) were measured for a small, arid-zone marsupial, the stripe-faced dunnart (Sminthopsis macroura), when normothermic and torpid. Metabolic rate increased linearly with decreasing ambient temperature (T_a) for normothermic dunnarts, and calculated metabolic water production (MWP) ranged from 0.85±0.05 (T_a=30°C) to 3.13±0.22 mg H₂O g^–1 h^–1 (T_a=11°C). Torpor at T_a=11 and 16°C reduced MWP to 24–36% of normothermic values. EWL increased with decreasing T_a, and ranged from 1.81±0.37 (T_a=30°C) to 5.26±0.86 mg H₂O g^–1 h^–1 (T_a=11°C). Torpor significantly reduced absolute EWL to 23.5–42.3% of normothermic values, resulting in absolute water savings of 50–55 mg H₂O h^–1. The relative water economy (EWL/MWP) of the dunnarts was unfavourable, remaining >1 at all T_a investigated, and did not improve with torpor. Thus torpor in stripe-faced dunnarts results in absolute, but not relative, water savings.     

Behavioral economic analysis of water intake in a laboratory rhesus macaque

Behavioral economics is useful for understanding the influence of environmental manipulation on a variety of behaviors, including drug self-administration, food intake, and stock behavior. The present study employed behavioral economics to investigate the psychologically satisfying amount of water intake in a laboratory rhesus macaque. Our institutional guidelines set a minimum amount of daily water intake. However, no study to date has determined whether that minimum amount is psychologically sufficient. In the present experiment, a monkey lived in an individual cage in which the only water available was delivered by chain pulling. A fixed number of responses was required for water delivery. This fixed ratio (FR) of responses per water delivery was progressively increased from FR 2 to FR 10. The study findings showed that during the FR 2 condition, demand for water was saturated at 131.3 ml/kg body weight (BW) (ranging from 95.1 to 211.2). The monkeys daily intake of water decreased as FR size incrementally increased, approaching an asymptote under the FR 8 and FR 10 conditions. During the FR 8 and FR 10 conditions, responding ceased when this monkey earned 53.5 ml/kg-BW (ranging from 32.7 to 74.9) of water. Therefore, the amount of water obtained under these conditions might provide a psychologically satisfying amount. Although these values were obtained from the behavioral study of one monkey, they were almost equivalent to values in our institutional guidelines that were determined by veterinary observations. These findings imply that behavioral economics is useful for studying the welfare of laboratory animals.     

The Characteristics and Trends of Socioeconomic Metabolism in China

China has become the country with the largest resource use and has high levels of waste emissions that pose a great management challenge. To provide more details about environmental problems and to find effective solutions, this article analyzed the scale, structure, and trend of the socioeconomic metabolism in China during the period 1992–2014 based on economy‐wide material flow accounts (EW‐MFA), and predicted resource use during the period of the 13th Five‐Year Plan. The results of this study show that the scale of China's socioeconomic metabolism in China increased more than twofold, during 1992–2014. However, after 2011, with the economic slowdown, the growth rates of total material requirement (TMR), direct material input (DMI), and domestic processed output (DPO) began to decrease. China may reach an inflection point, but this point will probably not be approached before the year 2020. Material recycling (MR) has played an important role in improving resource productivity, improving it by 92.52 renminbi per tonne in 2014. Metallic minerals and fossil fuels are the main sources of hidden flow. Carbon dioxide (CO₂) emissions, construction waste, and agricultural emissions have become the major sources of DPO. Because of the 13th Five‐Year Plan, China may slow the growth rate of DMI and may save 10.26 gigatonnes of resources during 2015–2020. Resource productivity is predicted to increase by 15.91%. Imports and MR may play more important roles. These suggestions are made: (1) strengthening the recycling system; (2) stronger policies, especially in metallic mineral and fossil fuels; (3) developing management systems for CO₂ emissions, construction waste, and agricultural emissions; and (4) adjusting China's economic structure.     

Using Web‐Based Technology to Bring Hands‐On Urban Material Flow Analysis to the Classroom

The main objective of this article is to introduce an open‐source, online software tool called OMAT as a teaching tool for performing economy wide‐material flow analysis (EW‐MFA) at urban or regional level in industrial ecology curricula. To that intent, we present a classroom and project activity that was developed for a masters‐level industrial ecology course offered by the Autonomous University of Barcelona. Insights are provided with regards to the outcome of the classroom exercise as well as lessons learned from both an academic and a software development point of view. The OMAT software provides users with a specialized tool to enter and process MFA data in a simple, intuitive way. The usefulness of OMAT as a teaching tool was tested by engaging students in a classroom activity that entailed using OMAT as a tool to perform an EW‐MFA applied to the Metropolitan Area of Barcelona for the years 2005‐2011. The aim of this exercise was to teach students specific skills required in performing an EW‐MFA, not through theory classes, but hands‐on through a learn‐as‐you‐go approach. The exercise not only equipped the students with knowledge about MFA, but also introduced them to solving problems as a team, meeting project deadlines, and communicating effectively with colleagues from different disciplines and backgrounds. Even though there is room for further improvements, this exercise showed that OMAT provided a useful addition to traditional methods that allowed students to get a more practical and thorough understanding of the MFA methodology.     

Uncertainties of Domestic Road Freight Statistics: Insights for Regional Material Flow Studies

Freight statistics are at the core of many studies in the field of industrial ecology because they depict the physical interdependencies of territories and allow links to be made worldwide between production and consumption. Recent studies have focused increasingly on subnational scales, often relying on domestic freight data. In this perspective, this article analyses the uncertainties of the French domestic road freight survey, road being by far the most common mode of transport in the country. Based on a statistical analysis of the survey, we propose a model to estimate the uncertainty of any given domestic road transport flow. We also assess uncertainty reduction when averaging the flows over several years, and obtain for instance a 30% reduction for a three‐year average. We then study the impact of the uncertainties on regional material flow studies such as the economy‐wide material flow analysis of the Bourgogne region. Overall the case studies advocate for a systematic assessment of freight uncertainties, as neither the disaggregation level nor the quantities traded are good enough predictors. This justifies the need for an easy‐to‐implement estimation model. Finally, basic comparison with the German and Swedish surveys tends to indicate that the main conclusions presented in this article are likely to be valid in other European countries.     

Living on the Margins: Livelihood Strategies of Bedouin Herd-Owners in the Northern Negev, Israel

Information collected on herding practices and economic activities of nine Bedouin households is used to define livelihood strategies and examine their economic viability. Large variations found in herding practices and other means of subsistence are a response to external policies and constraints which limit herding space and sources of income. Differential access to resources and different sociocultural norms are important factors. The identification and analysis of different livelihood strategies is a useful point of departure for discussing the development of Bedouin herding in the Negev and for formulating policy that is more effective and empathetic.     

Reproductive effort in desert versus mediterranean crucifers: the allogamous Erucaria rostrata and E. hispanica and the autogamous Erophila minima

Components of the total sexual investment of plants growing under mediterranean climatic and edaphic conditions were compared with those of plants growing in the desert, in the closely related allogamous species pair Erucaria hispanica and E. rostrata and in populations of the autogamous species Erophila minima. In all cases lower total investment was evident in the desert plants. At the prezygotic phase it was expressed by (1) reduced production of flowers; (2) lower allocation to the production of male gametophytes and some floral organs; and (3) packaging of more ovules per ovary. The ratio of reproductive: vegetative biomass which was found to be greater in the desert plants and their lower pollen: ovule ratio are perhaps indicative of greater efficiency. Their smaller investment at the postzygotic phase was expressed in: (1) reduction in total numbers of fruits and seeds; (2) decrease in seed size and weight. Yet in the desert plants the number of seeds per total biomass was found to be significantly larger and fertility rates (seed-set per ovule, fruit-set per flower per plant) were equal to or greater than those in the mediterranean plants. The trends observed in this study in desert plants, which may result in more efficient exploitation of resources, are similar in the species involved, regardless of their breeding system-autogamous or allogamous.     

Prey capture by three Pinguicula species in a subarctic environment

The number and biomass of prey captured were estimated for Pinguicula alpina, P. villosa and P. vulgaris in a subarctic environment. Seasonal captures were estimated for one site per species for 4–5 years. Captures were related to reproductive status (reproductive/non-reproductive) and to leaf area. For one species (P. vulgaris) the catch was also compared across a range of habitats. Of the seasonal catch, 50–75% was obtained during June and less than 5% during August. For P. alpina and P. villosa the seasonal catch varied threefold or more between years (means of 89–329 g dry matter plant^–1 season^–1 for P. alpina, and 11–91 g dry matter plant^–1 season^–1 for P. villosa), whereas the between-year variation for P. vulgaris was small (mean c. 600 g plant^–1 season^–1). Large variations were, however, observed among habitats for P. vulgaris. Captured prey may contribute a substantial amount of nutrients to the most successful individuals (up to 85% of the mean seasonal turnover), but prey capture varied greatly and during any given season many individuals obtained only marginal amounts of nutrients through carnivory. P. vulgaris trapped almost twice as much per unit leaf area and season as the other two species (224 for P. vulgaris versus 127 g cm^–2 season^–1 for the other two species). Reproductive individuals of P. vulgaris trapped almost twice as much as non-reproductive individuals (after taking differences in leaf area into account). For the other two species no differences were observed between reproductive and non-reproductive individuals.     

Maximal oxygen uptake, anaerobic threshold and running economy in women and men with similar performances level in marathons

Sex differences in running economy (gross oxygen cost of running, C_R), maximal oxygen uptake (VO_2max), anaerobic threshold (Th_an), percentage utilization of aerobic power (% VO_2max), and Th_an during running were investigated. There were six men and six women aged 20–30 years with a performance time of 2 h 40 min over the marathon distance. The VO_2max, Th_an, and CR were measured during controlled running on a treadmill at 1° and 3° gradient. From each subject's recorded time of running in the marathon, the average speed (v _M) was calculated and maintained during the treadmill running for 11 min. The VO_{2 max} was inversely related to body mass (m _b), there were no sex differences, and the mean values of the reduced exponent were 0.65 for women and 0.81 for men. These results indicate that for running the unit ml·kg^–0.75·min^–1 is convenient when comparing individuals with different m _b. The VO_2max was about 10% (23 ml·kg^–0.75·min^–1) higher in the men than in the women. The women had on the average 10–12 ml·kg^–0.75·min^–1 lower VO₂ than the men when running at comparable velocities. Disregarding sex, the mean value of C_R was 0.211 (SEM 0.005) ml·kg^–1·m^–1 (resting included), and was independent of treadmill speed. No sex differences in Th_an expressed as % VO_2max or percentage maximal heart rate were found, but Than expressed as VO₂ in ml·kg^–0.75·min^–1 was significantly higher in the men compared to the women. The percentage utilization of f _emax and concentration of blood lactate at v _M was higher for the female runners. The women ran 2 days more each week than the men over the first 4 months during the half year preceding the marathon race. It was concluded that the higher VO_2max and Th_an in the men was compensated for by more running, superior C_R, and a higher exercise intensity during the race in the performance-matched female marathon runners.