Earthworm burrowing in laboratory microcosms as influenced by soil temperature and moisture

Earthworm burrows contribute to soil macroporosity and support diverse microbial communities. It is not well known how fluctuations in soil temperature and moisture affect the burrowing activities of earthworms. The objective of this experiment was to evaluate the maximum depth and length of burrows created by the endogeic earthworm Aporrectodea caliginosa (Savigny) and the anecic earthworm Lumbricus terrestris L. for a range of temperatures (5–20 °C) and soil water potentials (−5 and −11 kPa). The laboratory microcosm was a plexiglass chamber (45 cm high, 45 cm wide) containing 0.14 m² of pre-moistened soil and litter, designed to house a single earthworm for 7 days. Earthworm mass, surface casting and burrowing activities were affected significantly by soil temperature, moisture and the temperature×moisture interaction. Burrow length and maximum burrow depth increased with increasing temperature, but there was less burrowing in wetter soil (−5 kPa) than drier soil (−11 kPa). Weight gain and surface casting, however, were greater in soil at −5 kPa than −11 kPa. Our results suggest more intensive feeding and limited burrowing in wetter soil than drier soil. Earthworms inhabiting the non-compacted, drier soil may have pushed aside particles without ingesting them to create burrows. The result was that earthworms explored a larger volume of soil, deeper in the chamber, when the soil was drier. How these burrowing activities may affect the community structure and activity of soil microorganisms and microfauna in the drilosphere remains to be determined.     

Nutrient disorders of Dianthus ‘Bouquet Purple’

‘Bouquet Purple’ pinks (Dianthus sp.) were grown in silica-sand culture to induce and photograph symptoms of nutritional disorders. Plants received a complete modified Hoagland's all-nitrate (NO₃) solution. Nutrient-deficient treatments were induced with a complete nutrient formula minus one of the nutrients, and a boron (B)-toxicity treatment was induced by increasing B 10-fold in the complete nutrient formula. Plants were monitored daily to document sequential series of symptoms as they developed. Typical symptomology of nutrient disorders and corresponding tissue concentrations were determined. All treatments exhibited deficiency symptomology. Disorders for nitrogen (N), iron (Fe), calcium (Ca), and sulfur (S) were the first to manifest in pinks. Unique symptomology was observed for plants grown under potassium- (K), B-, copper- (Cu), and molybdenum- (Mo) deficient conditions, which supported the need for a species-specific approach when characterizing nutrient disorders of floriculture crops.     

Landscape conditions predisposing grizzly bears to conflicts on private agricultural lands in the western USA

We used multiple logistic regression to model how different landscape conditions contributed to the probability of human-grizzly bear conflicts on private agricultural ranch lands. We used locations of livestock pastures, traditional livestock carcass disposal areas (boneyards), beehives, and wetland-riparian associated vegetation to model the locations of 178 reported human-grizzly bear conflicts along the Rocky Mountain East Front, Montana, USA during 1986-2001. We surveyed 61 livestock producers in the upper Teton watershed of north-central Montana, to collect spatial and temporal data on livestock pastures, boneyards, and beehives for the same period, accounting for changes in livestock and boneyard management and beehive location and protection, for each season. We used 2032 random points to represent the null hypothesis of random location relative to potential explanatory landscape features, and used Akaike’s Information Criteria (AIC/AIC_C) and Hosmer-Lemeshow goodness-of-fit statistics for model selection. We used a resulting “best” model to map contours of predicted probabilities of conflict, and used this map for verification with an independent dataset of conflicts to provide additional insights regarding the nature of conflicts. The presence of riparian vegetation and distances to spring, summer, and fall sheep or cattle pastures, calving and sheep lambing areas, unmanaged boneyards, and fenced and unfenced beehives were all associated with the likelihood of human-grizzly bear conflicts. Our model suggests that collections of attractants concentrated in high quality bear habitat largely explain broad patterns of human-grizzly bear conflicts on private agricultural land in our study area.     

Ethanol-dependent heat-induced dissociation of casein micelles

The dissociation of casein micelles when heated to approximately 65 degrees C in the presence of ethanol [1:1 mixture (v/v) of milk and 65% (w/w) aqueous ethanol] was investigated using L* values and transmission measurements. Mixtures of milk and ethanol became transparent on heating, which suggests dissociation of casein micelles. Results of experiments using confocal laser scanning microscopy, light scattering (static and dynamic), and dialysis to examine the changes of milk during heating in the presence of ethanol supported the assertion that such treatments result in dissociation of casein micelles, as did studies of model beta-casein micellar systems.     

Increasing expression of an anti-picloram single-chain variable fragment (ScFv) antibody and resistance to picloram in transgenic tobacco (Nicotiana tabacum)

Systematic research involving four chimeric gene constructions designed to express the same anti-picloram single-chain variable fragment (scFv) antibody is described. Agrobacterium-mediated transformation produced at least 25 transgenic tobacco plants with each of these, and the number of T-DNA loci in each plant was determined using kanamycin-resistance segregation assays. The relative amounts of active and total scFv in each plant were evaluated using quantitative enzyme-linked immunosorbent assay and immunoblot technologies, respectively. No significant differences in scFv activity were found among the four groups of single-locus plants, although the 35S/M construct was found to produce significantly more total anti-picloram scFv than the other three constructs. A dose-response bioassay involving T(1) seedlings from several of the highest expressers of active scFv demonstrated resistance to a constant exposure of picloram at 5 x 10(-)(8) M. Other approaches for increasing antibody-based herbicide resistance are discussed, as further improvements are needed before practical application of this technology.     

Differences between new england coastal fog and mountain cloud water chemistry

Major inorganic ions and pH were analyzed from mountain cloud and coastal fog water event samples from New Hampshire and Maine, U.S.A. Based on marine corrected values, the medians for coastal fog were still up to three times higher in ionic concentrations and lower in pH, compared to mountain clouds. Of the acidic constituents, nitrate concentrations were considerably higher in coastal fogs, which correlates with higher concentrations of 03 measured along the New England coast. It is hypothesized that meteorological conditions permit air pollutants emitted in the northeastern US urban corridor to move relatively intact across the Gulf of Maine and to interact with the coastal fogs, which results in differences in the chemistry of coastal fogs and mountain clouds.     

The effects of visual apparency on bias in butterfly recording and monitoring

A basic assumption in conservation is that comparable data are available for species to facilitate risk assessment of extinction. However, the capacity for carrying out cross-species comparisons for abundances and distributions among butterflies depends on the absence of bias in recording and monitoring or the existence of appropriate techniques for removing bias. Here, we investigate potential bias in cross-species comparisons for the apparency of butterfly adults (wing colour, size and behaviour) in three pivotal UK datasets: dates of discovery, Butterfly Monitoring Scheme (BMS) transect measures of abundance and Butterflies for the New Millennium (BNM) national recording scheme. Bias is found in all three datasets. Discovery date is affected by wing colour and size, BNM recording by adult behaviour and wing colour and BMS monitoring by adult behaviour. The nature and degree of bias differs between uncorrected cross-species comparisons and those with the application of phylogenetic contrasts. The findings urge caution in using these datasets for cross-species analysis without improvements and standardisation of recording and monitoring and the development of techniques to adjust for biases, in particular the use of suitable comparative techniques. The latter requires the construction of a molecular phylogeny for butterflies.     

HeathMod: a model of the impact of seasonal grazing by sheep on upland heaths dominated by Calluna vulgaris (heather)

The dwarf shrub heather Calluna vulgaris is an important component of the UK landscape, with value for amenity, nature conservation and animal production. A model, called “HeathMod”, is described, which investigates the impact of grazing on upland heather. It combines an empirical model of production with a simple process-based model of grazing impacts. Validation from short-term studies in the literature indicated that the model predicts grazing impacts well, although more studies of grazing impacts are required to confirm the model’s accuracy. Analysis of the model allowed derivation of a simple general formula for predicting sustainable levels of grazing, given knowledge of local site productivity. Predicted levels of sustainable grazing were lower than previous estimates, mainly because the model predicts the long-term impacts of sustained grazing. Application of the model is most appropriate in areas where heather is in mixed-age stands, because there is inadequate information available to model interactions between grazing and degeneration in even-aged stands of heather.     

Land management effects on the near-surface physical quality of a clay loam soil

Although agricultural land management is known to affect near-surface soil physical quality (SPQ), the characteristics of these affects are poorly understood, and diagnostic SPQ indicators are not well-developed. The objective of this study was to measure a suite of potential SPQ indicators using intact soil cores and grab samples collected from the 0–10 cm depth of a clay loam soil with the treatments: (i) virgin soil (VS); (ii) long-term continuous bluegrass sod (BG); (iii) long-term maize (Zea mays L.)—soybean (Glycine max (L.) Merr.) rotation under no-tillage (NT); (iv) long-term maize–soybean rotation under mouldboard plough tillage (MP); (v) short-term (1–4 years) NT after long-term MP; (vi) short-term MP after long-term BG; (vii) short-term MP after long-term NT. Organic carbon content, dry bulk density, air capacity, relative water capacity and saturated hydraulic conductivity appeared to be useful SPQ indicators because they were sensitive to land management, and proposed optimum or critical values are available in the literature. Soil macroporosity was also sensitive to land management, but optimum or critical values for this parameter are not yet established. Soil matrix porosity and plant-available water capacity did not respond substantially or consistently to changes in land management, and were thus not useful as SPQ indicators in this study. Converting long-term BG to MP caused overall SPQ to decline to levels similar to long-term MP within 3–4 years. Converting long-term NT to MP or vice versa caused only minor changes in overall SPQ. With respect to the measured SPQ indicators and their optimum or critical values, both VS and BG produced “good” overall SPQ in the near-surface soil, while long-term maize–soybean rotation under NT and MP produced equally “poor” SPQ.     

Systematic reserve design as a dynamic process: F-TRAC and the Florida Forever program

Systematic conservation planning has become an important tool for increasing the efficiency of conservation decisions, but many planning efforts result in static plans that may lose relevance over time. We developed a process whereby planning is integrated into the decision-making process and updated every six months in response to conservation actions. The Florida Forever program is a 10-year, $3 billion land acquisition program expected to acquire approximately 1.25 million acres (607,000 ha) for conservation in Florida through the year 2010. With limited funding and duration, the program needs to be able to efficiently protect the most natural resources for a fixed cost, a situation well suited to a systematic reserve design approach. To inform this program, we conducted an assessment of natural resource conservation needs and developed the Florida Forever Tool for Efficient Resource Acquisition and Conservation (F-TRAC), a systematic reserve design analysis based on a simulated annealing site selection algorithm using Marxan software. The analysis considered conservation needs for a variety of natural resources including species, natural communities, high quality watersheds, wetlands, and sustainable forestry. Each 6-month analysis identifies an efficient portfolio of sites for resource protection, given the amount of land area likely remaining to be acquired by the Florida Forever program. The Spring 2004 model portfolio had a cost threshold of 206,308 ha, met conservation targets for 18 of 32 resource conservation features, and identified approximately 116,000 ha outside of current land acquisition projects. This study also demonstrates the use of reserve design results to evaluate existing and proposed land acquisition projects and inform decision makers; and the evaluation of acquisition trends and program success based on potential achievements as indicated by reserve design analyses.