Glyn M. Rimmington

Developing global awareness and responsible world citizenship with global learning

Global learning is a student-centered activity in which learners of different cultures use technology to improve their global perspectives while remaining in their home countries. This article examines the use of global learning with gifted students to develop the knowledge, attitudes, and skills necessary for world citizenship. We describe a pedagogical approach that is based on a set of conditions for global learning, associated learner attributes, and processes developed in global learning leading to acquisition of world citizen characteristics. Six processes and nine attributes are identified as essential for global learning. Two examples are presented of how this approach can be used to integrate global learning into the curriculum—one at a university level and another in a middle-school setting.

Forecasting Wheat Yields in Australia with the Southern Oscillation Index

Wheat yields in Australia have been correlated with values of the Southern Oscillation Index (SOI), an index of a major climatic phenomenon known to affect Australian rainfall. The SOI provides the basis for the seasonal prediction of rainfall. Values of the SOI, routinely available before and near the sowing date, can provide skilful yield forecasts. These forecasts would be available several months before harvest starts, require little data, and are quick and easy to prepare. The best predictors appear to be trends in the SOI, i.e. the SOI values near planting minus the values in the previous year, rather than absolute values. Wheat yield is negatively correlated with the SOI of the year prior to planting and positively correlated with the SOI during the crop season. The skill levels of SOI vary from r2 = 36% for Queensland to r2 = 6% for South Australia.

Complexity in landscape ecology

Foreword.- Preface.- 1. Complexity and ecology.- 2. Seeing the wood for the trees.- 3. Complexity in landscapes.- 4. Oh, what a tangled web.- 5. The imbalance of nature.- 6. Populations in landscapes.- 7. Living with the neighbours.- 8. Genetics and adaptation in landscapes.- 9. Virtual worlds.- 10. Digital ecology.- 11. The global picture.- References.- Index.

Soil respiration in different agricultural and natural ecosystems in an arid region.

The variation of different ecosystems on the terrestrial carbon balance is predicted to be large. We investigated a typical arid region with widespread saline/alkaline soils, and evaluated soil respiration of different agricultural and natural ecosystems. Soil respiration for five ecosystems together with soil temperature, soil moisture, soil pH, soil electric conductivity and soil organic carbon content were investigated in the field. Comparing with the natural ecosystems, the mean seasonal soil respiration rates of the agricultural ecosystems were 96%–386% higher and agricultural ecosystems exhibited lower CO2 absorption by the saline/alkaline soil. Soil temperature and moisture together explained 48%, 86%, 84%, 54% and 54% of the seasonal variations of soil respiration in the five ecosystems, respectively. There was a significant negative relationship between soil respiration and soil electrical conductivity, but a weak correlation between soil respiration and soil pH or soil organic carbon content. Our results showed that soil CO2 emissions were significantly different among different agricultural and natural ecosystems, although we caution that this was an observational, not manipulative, study. Temperature at the soil surface and electric conductivity were the main driving factors of soil respiration across the five ecosystems. Care should be taken when converting native vegetation into cropland from the point of view of greenhouse gas emissions.

Effects of temperature and leaf wetness duration on infection of pear leaves by Venturia pirina

The effects of temperature and wetness duration on the infection of pear leaves (Pyrus communis L.) by Venturia pirina were studied by inoculating plants with ascospores and conidia under controlled conditions and in the field. Under controlled inoculations, minimum wetness durations that lead to leaf infections by ascospores were 27, 15, 13, 11, 10, 9, and 9 h at 4, 8, 10, 12, 15, 20, and 25°C, respectively. In parallel inoculations with conidia, the minimum wetness durations that lead to leaf infections were similar to ascospores at temperatures between 12°C and 25°C, but at lower temperatures (4, 8, 10°C), conidia infected leaves only after an additional 2 h of leaf wetness. The relationship between minimum wetness times and temperature was best described using an exponential regression. In field experiments, leaf infection on plants inoculated with ascospores and conidia under various naturally occurring wetness and temperature conditions was in close agreement with those under controlled conditions. Disease severity (percent of leaf area infected) increased with increasing leaf wetness duration at all temperatures. The optimum temperature for infection was 20°C. Analysis of variance with orthogonal polynomial contrasts was used to define the relationship of the angular transformation of disease severity to temperature and leaf wetness duration.

Monitoring plant response to phenanthrene using the red edge of canopy hyperspectral reflectance

To investigate the mechanisms and potential for the remote sensing of phenanthrene-induced vegetation stress, we measured field canopy spectra, and associated plant and soil parameters in the field controlled experiment in the Yellow River Delta of China. Two widely distributed plant communities, separately dominated by reed (Phragmites australis) and glaucous seepweed (Suaeda salsa), were treated with different doses of phenanthrene. The canopy spectral changes of plant community resulted from the decreases of biomass and foliar projective coverage, while leaf photosynthetic pigment concentrations showed no significance difference among treatments. The spectral response to phenanthrene included a flattened red edge, with decreased first derivative of reflectance. The red edge slope and area consistently responded to phenanthrene, showing a strong relationship with aboveground biomass, coverage and canopy pigments density. These results suggest the potential of remote sensing and the importance of field validation to correctly interpret the causes of the spectral changes.

Soil TPH concentration estimation using vegetation indices in an oil polluted area of eastern China.

Assessing oil pollution using traditional field-based methods over large areas is difficult and expensive. Remote sensing technologies with good spatial and temporal coverage might provide an alternative for monitoring oil pollution by recording the spectral signals of plants growing in polluted soils. Total petroleum hydrocarbon concentrations of soils and the hyperspectral canopy reflectance were measured in wetlands dominated by reeds (Phragmites australis) around oil wells that have been producing oil for approximately 10 years in the Yellow River Delta, eastern China to evaluate the potential of vegetation indices and red edge parameters to estimate soil oil pollution. The detrimental effect of oil pollution on reed communities was confirmed by the evidence that the aboveground biomass decreased from 1076.5 g m−2 to 5.3 g m−2 with increasing total petroleum hydrocarbon concentrations ranging from 9.45 mg kg−1 to 652 mg kg−1. The modified chlorophyll absorption ratio index (MCARI) best estimated soil TPH concentration among 20 vegetation indices. The linear model involving MCARI had the highest coefficient of determination (R 2 = 0.73) and accuracy of prediction (RMSE = 104.2 mg kg−1). For other vegetation indices and red edge parameters, the R2 and RMSE values ranged from 0.64 to 0.71 and from 120.2 mg kg−1 to 106.8 mg kg−1 respectively. The traditional broadband normalized difference vegetation index (NDVI), one of the broadband multispectral vegetation indices (BMVIs), produced a prediction (R 2 = 0.70 and RMSE = 110.1 mg kg−1) similar to that of MCARI. These results corroborated the potential of remote sensing for assessing soil oil pollution in large areas. Traditional BMVIs are still of great value in monitoring soil oil pollution when hyperspectral data are unavailable.

Environmental factors influencing maturation and release of ascospores of Venturia pirina in Victoria, Australia

The influence of moisture, light, and temperature on Venturia pirina ascospore maturation and discharge was studied during 1992–99 in 2 pear-growing regions in Victoria. In each year and site, mature ascospores were trapped over a 3-month period beginning a few days before or at the green-tip stage of pear tree development in early September and ending in late November, with the majority of ascospores ((>80%) trapped between green-tip and petal-fall. Ascospore discharge was associated with rain and dew, with 90–98% of the season’s total number of ascospores trapped during rain events and 2–10% trapped during dew events in the 12 data sets examined. Most ascospores were trapped (82.5– 99.9%) during daytime (0600–1800 hours). The 0.1–17.5% of ascospores detected during night time (1900–0500 hours) were trapped mainly within 1–3 h of dawn or dusk. There were linear relationships between the logit of cumulative percentage of ascospore maturation and temperature accumulation (above 0 degree-days), calculated both daily and for days with >= 0.2 mm of rainfall. Six linear regression equations were formulated with 10 years of field data and using the 2 methods of accumulating degree-days, to predict the cumulative percentage of matured ascospores. Predictions were compared with additional field and laboratory observations not used in the formulation of the linear equations. The importance of the temperature-based linear equations is discussed in relation to the prediction of pear scab ascospore maturity for use in a pear scab management program.

Effects of Added Organic Matter and Water on Soil Carbon Sequestration in an Arid Region

It is generally predicted that global warming will stimulate primary production and lead to more carbon (C) inputs to soil. However, many studies have found that soil C does not necessarily increase with increased plant litter input. Precipitation has increased in arid central Asia, and is predicted to increase more, so we tested the effects of adding fresh organic matter (FOM) and water on soil C sequestration in an arid region in northwest China. The results suggested that added FOM quickly decomposed and had minor effects on the soil organic carbon (SOC) pool to a depth of 30 cm. Both FOM and water addition had significant effects on the soil microbial biomass. The soil microbial biomass increased with added FOM, reached a maximum, and then declined as the FOM decomposed. The FOM had a more significant stimulating effect on microbial biomass with water addition. Under the soil moisture ranges used in this experiment (21.0%–29.7%), FOM input was more important than water addition in the soil C mineralization process. We concluded that short-term FOM input into the belowground soil and water addition do not affect the SOC pool in shrubland in an arid region.

Strong light inhibits germination of Artemisia sphaerocephala and A. ordosica at low temperature and its relevance to revegetation in sandy lands of Inner Mongolia, China

Artemisia sphaerocephala and A. ordosica are two dominant shrub species in Mu Us sandy land (Inner Mongolia, China) and are widely used for vegetation restoration. However, there are two different conclusions about the effect of light on their germination: light promotes germination versus light inhibits germination. The aim of this study was to evaluate these two conclusions and relate the results to instances of failure of these two species to germinate well when air-dispersed in revegetation projects. The effects of fluctuating temperature, light/dark, source (population), position on mother plant, storage condition, and storage time were tested on germination of achenes of these two species. At low temperature, final percent germination (FPG) of achenes in dark and nearly dark conditions was significantly higher than those in light. At 10:20°C, achenes of both A. sphaerocephala and A. ordosica had higher FPG in dark than in light regardless of source, position on mother plants or storage condition. At suboptimum (5:15°C) and supraoptimal (25:35°C) temperatures, germination of A. sphaerocephala and A. ordosica achenes was inhibited in both light and darkness. It was concluded that light inhibits germination of A. sphaerocephala and A. ordosica achenes at low (10:20°C) temperature but not at high (15:25°C) temperature. Since the temperature in Mu Us sandy land is around 10:20°C in early June, when air sowing is done, achenes should germinate best when they are covered by a thin layer of sand.