Managing compost stability and amendment to soil to enhance soil heating during soil solarization

Soil solarization is a method of soil heating used to eradicate plant pathogens and weeds that involves passive solar heating of moist soil mulched (covered) with clear plastic tarp. Various types of organic matter may be incorporated into soil prior to solarization to increase biocidal activity of the treatment process. Microbial activity associated with the decomposition of soil organic matter may increase temperatures during solarization, potentially enhancing solarization efficacy. However, the level of organic matter decomposition (stability) necessary for increasing soil temperature is not well characterized, nor is it known if various amendments render the soil phytotoxic to crops following solarization. Laboratory studies and a field trial were performed to determine heat generation in soil amended with compost during solarization. Respiration was measured in amended soil samples prior to and following solarization as a function of soil depth. Additionally, phytotoxicity was estimated through measurement of germination and early growth of lettuce seedlings in greenhouse assays. Amendment of soil with 10% (g/g) compost containing 16.9 mg CO₂/g dry weight organic carbon resulted in soil temperatures that were 2–4 °C higher than soil alone. Approximately 85% of total organic carbon within the amended soil was exhausted during 22 days of solarization. There was no significant difference in residual respiration with soil depth down to 17.4 cm. Although freshly amended soil proved highly inhibitory to lettuce seed germination and seedling growth, phytotoxicity was not detected in solarized amended soil after 22 days of field solarization.     

A classification of backcountry campsites in Prince William Sound,Alaska, USA

This study examined resource conditions on backcountry campsites in Prince William Sound, Alaska, USA. In order to further the understanding of campsite impacts and to improve monitoring and assessment methods, we employed a multivariate analysis procedure, suggested in one study, but heretofore untested on data from other campsite assessments. Factor analysis of ten impact indicator variables from 146 campsites produced three dimensions of campsite impact—tree and vegetation disturbance, areal disturbance and visitor behavior-related disturbance. Three types of campsites, which differed substantially in the types of impact exhibited, were then derived from a cluster analysis of the factor scores. Further analysis revealed a significant relationship between the types of substrates where campsites were located and the types of campsites derived from the analysis. This work illustrates the utility of multi-indicator monitoring approaches and the use of multivariate methods for classifying campsites, as the campsite types identified would likely require different management strategies for limiting the proliferation and expansion of impacts.     

Multi-year lactation and its consequences in Bornean orangutans (Pongo pygmaeus wurmbii)

In most mammals, females pay for reproduction by dramatically increasing net energy intake from conception to mid- or late lactation. To do this, they time their reproductive events in relation to environmental cycles so that periods of peak food availability coincide with peak demand or are used to build energy stores. This timing is not possible in species with slow development in which lactation is prolonged over a multi-year period with fluctuating food availability. Here, mothers are expected to sustain a stable but generally lower level of nutrient transfer. In a sample of over 1,050 complete follow days of eight mother–infant pairs collected over 7 years, we document maternal effort for wild Bornean orangutans (Pongo pygmaeus wurmbii) over their average 6.5-year lactation period. As predicted, maternal feeding time was independent of the age of her growing offspring, indicating a stable sustained “plateau” effort of ≤ 25 % above baseline level, instead of a short peak lactation as seen in seasonal breeders. Infant orangutans started to regularly supplement milk with self-harvested food when they were 1–1.5 years old, indicating milk intake was insufficient from this age onwards, even though maternal effort did not decrease. We expect the same regulation of sustained maternal effort in other large and large-brained mammals with slow infant development. We also predict that mother–infant conflict over suckling may show another peak at the onset of the milk?+?solid food phase, in addition to the well-known conflict around the endpoint of lactation (weaning), which is reached after a long and gradual increase in solid food intake by the infant.     

Behavioural syndromes in juvenile brown trout (<Emphasis Type="Italic">Salmo trutta</Emphasis>); life history,family variation and performance in the wild

The main aims of this study were to investigate (1) the occurrence and strength of the shyness–boldness behavioural syndrome in brown trout fry, (2) whether this syndrome is associated with paternal migratory life history, (3) whether fry survival and growth in the wild is associated with paternal life history and/or boldness and (4) whether offspring performance showed maternal effects. Nine female migratory trout were each crossed with one migratory and one resident male and the offspring were raised in hatchery tanks until first feeding. The behavioural studies showed that fry that responded bold towards a novel object also accepted a novel food item earlier and responded more aggressively towards their own mirror image. Principal component analysis showed that this shyness–boldness syndrome (PC1) explained 34% of the behavioural variation. Offspring boldness was not affected by paternal migratory life history, but significant effects of the female parent suggested maternal and/or genetic effects. Deviations from this pattern (PC2), where some individuals behaved less aggressively and performed more approaches to food, explained an additional 17% of the variation in behaviour, and was significantly influenced by length and paternal migratory life history. Fry growth and survival in nature was not associated with boldness (PC1) or PC2, suggesting that alternative behavioural strategies can be successful in nature. However, female parent effects on variation in fry size persisted over the first growth period in the wild, suggesting that these effects may influence offspring fitness during early life when major selection occurs.     

Universities and Climate Change Mitigation: Advancing Grassroots Climate Policy in the US

While US climate change mitigation policy has stalled at the national level, local and regional actors are increasingly taking progressive steps to reduce their greenhouse gas emissions. Universities are poised to play a key role in this grassroots effort by targeting their own emissions and by working with other local actors to develop climate change mitigation programmes. Researchers at the Pennsylvania State University have collaborated with university administrators and personnel to inventory campus emissions and develop mitigation strategies. In addition, they have facilitated a stakeholder-driven climate change mitigation project in one Pennsylvania county and started an ongoing service-learning project aimed at reducing emissions in another county. These campus and community outreach initiatives demonstrate that university-based mitigation action may simultaneously achieve tangible local benefits and develop solutions to broader challenges facing local climate change mitigation efforts. Outcomes include improved tools and protocols for measuring and reducing local emissions, lessons learned about service-learning approaches to climate change mitigation, and methods for creating climate change governance networks involving universities, local governments and community stakeholders.     

Fungal inoculum properties: extracellular enzyme expression and pentachlorophenol removal by New Zealand trametes species in contaminated field soils

This study was conducted to improve the ability of indigenous New Zealand white-rot fungi to remove pentachlorophenol (PCP) from contaminated field soil. The effects of different bioaugmentation conditions on PCP removal and extracellular enzyme expression were measured in the laboratory. The conditions were fungal growth substrate and co-substrate composition, culture age, and Tween 80 addition to the contaminated soil. The fungi used were Trametes versicolor isolate HR131 and Trametes sp. isolate HR577. Maximum PCP removal was 70% after 7 wk from a 1043 mg kg(-1) PCP-contaminated soil inoculated with an 11-d-old fungal culture of T. versicolor isolate HR131. There was minimal production of undesirable pentachloroanisole by the fungi. Tween 80 addition had no affect on PCP removal. Poplar sawdust was more suitable as a fungal growth substrate and a co-substrate amendment for PCP removal and extracellular enzyme expression than the locally available pine and fir sawdust. Pentachlorophenol removal was not necessarily correlated with extracellular enzyme expression. The research results demonstrate that PCP biodegradation was affected by inoculum culture age, by the presence of a co-substrate amendment, and by growth substrate composition after white-rot fungal bioaugmentation into PCP-contaminated field soils.