Impact of sampling and storage technique,and duration of storage,on the composition of fresh grass when analysed using near‐infrared reflectance spectroscopy

The objective of this study was to examine the effect of sampling technique (pluck or cut), storage duration (immediate analysis, 24‐h or 48‐h), storage temperature (ambient or chilled) and storage conditions (air present, air excluded or breathable) on the composition of fresh grass sampled from a sward managed to simulate grazing. Treatments were repeated across four sampling dates, with grass samples stored in grip seal bags prior to analysis using near‐infrared reflectance spectroscopy. Grass sampled by ‘pluck’ had a higher crude protein and ME content, and a lower acid detergent fibre (ADF) content, compared to that sampled by ‘cut’. Grass stored for 48 h had a lower water soluble carbohydrate (WSC) and ME content and a higher ADF content than for immediate analysis. Samples stored for 24 h did not differ from immediate analysis. Grass stored at ambient temperature had a lower WSC and ME content compared to immediate analysis. Grass stored under ‘breathable’ conditions had a lower ME content and higher ADF content than immediate analysis or samples stored with air present or air excluded. It is recommended that grass for analysis should be sampled by cutting, stored chilled (4°C) in a sealed bag to minimize exposure to oxygen and analysed within 24 h of harvest.     

Rheological Studies on the Reaction of Zein with Polyethylenemaleic Anhydride

There continues to be interest in developing solvent‐resistant articles from biobased renewable materials to successfully compete with petrochemical products. It was previously shown that reaction of zein with polyethylenemaleic anhydride (PEMA) provides articles that are solvent resistant. The gelation kinetics for the reaction of PEMA with zein was investigated rheologically to better understand this chemistry. The reaction of the nucleophilic groups on zein with the anhydrides on PEMA is the main cause for the gelation reaction. The gelation time was defined as being the point when the elastic modulus (G′) and viscous modulus (G″) cross. In this work, the rate of reaction, in terms of time to gelation, was studied in N,N‐dimethylformamide solution for which the amount of PEMA, the reaction temperature, and the overall reaction concentration were varied. Exponential relationships were found between the gelation time and % PEMA, temperature, and % solids, as well as between elastic modulus with either % PEMA or % solids. The concentration of PEMA had the largest impact on gelation time, for which going from 2.5% PEMA to 6% PEMA reduced the gelation time from 63,114 to 1,576 s. The temperature dependence of this gelation reaction was well described by an Arrhenius plot with an apparent activation energy of 50.5 kJ/mol.     

The potential of intercropping as an alternative land use system in temperate North America

The success of many intercropping systems in North America is attributable to the generation of a short term return from an agricultural crop during the early, unprofitable years of a longer term crop that is fruit, nuts or wood. This highly-efficient use of land and related profitability are important not only in the development of intercropping systems per se, but also in other applications which have tremendous potential independent of profitability. For example, intercropping can be effectively used during the establishment phases of hardwood plantations where it is essential to have a high level of weed control, the costs of which are often recovered with the agricultural production. Intercropping can also be used to grow trees rapidly and with a form that can be easily integrated into recreational or park situations, or urban fringe areas. In an urban context, intercropping can be used to grow trees in agricultural areas that are likely to be developed where traditional forestry options are not appropriate and the value of younger, thrifty trees may enhance property values far in excess of the cash value of the wood.     

Microclimate and soil moisture effects of three intercrops on the rows of a newly-planted intercropped plantation

Trees are grown in intercropping systems for a variety of purposes including wood products, fuelwood, fruit, forage or conservation purposes. No matter what end use, different tree/crop combinations interact differently resulting in differential growth rates of the trees during establishment. Preliminary work has shown that seedling growth and survival of trees are related to their intercrop and the results of this study help to explain these findings. Soil water potential, soil and air temperature, relative humidity, windspeed, and light (photosynthetic photon flux density — PPFD) were measured throughout the growing season in the clean-weeded treerows within crops of corn, soybeans and winter wheat. Crop height and biomass were also measured. This study was conducted during the 1992 growing season which was unusually cool and wet from mid June into the winter. The growth of winter wheat, measured by crop height and above-ground biomass, was earlier in the season than that of soybeans and corn, and this pattern affected the environmental conditions in the tree rows. Soil water potential was affected with associated effects on soil temperature (in combination with other factors). Crop height drastically reduced windspeed in the corn treatment from July through winter, also affecting PPFD and soil temperature later in the year. Although many microclimate differences were relatively small, data from subsequent years as well as associated soil moisture studies and additional years will help to further elucidate these relationships.     

The effect of cattle foot traffic on soil compaction in a silvo-pastoral system

In India, small farmers have generally found that the growing of eucalypts as a cash crop provides poor returns, and many have reverted to growing annual crops. Farmgate prices have been much lower than retail prices, due to the existence of middlemen, and retail prices have fallen to lower levels than expected as markets have become saturated. This article describes the situation in eastern Gujarant, where farmers sold their eucalypts directly to buyers at prices close to those in organised wood markets. An important reason for this unusual situation is the absence in Gujarat of controls on eucalyptus sales, which has helped producers to avoid dependence on rent-seeking intermediaries. The survey shows that growing eucalyptus can be a profitable activity for small farmers, given the right circumstances.     

Landowner perceptions and the adoption of agroforestry practices in southern Ontario,Canada

A mail-out survey questionnaire was developed by the Agroforestry group at the University of Guelph to determine the level of awareness and interest in the adoption of agroforestry systems by landusers from four townships in Wellington County, Ontario. The questionnaire investigated: (1) the current level of knowledge regarding windbreaks, woodlots and plantations, intereropping, riparian plantations and silvipasture, (2) the present level of participation in each of these systems on-farm, (3) the perceived benefits and/or drawbacks of each of these initiatives with respect to total farm income, income diversity, land rehabilitation, land value/equity, soil/water conservation, labour intensity, overhead and return on the term of investment.The majority of respondents were familiar with conventional agroforestry systems such as windbreaks and woodlots/plantations (80%, 62% respectively), therefore the level of interest in the adoption of these practices was significant (74%, 66% respectively). Response rates were lower for silvipasture, riparian plantations and intercropping, most likely as result of the low level of familiarity with these practices (20%, 32%, 4% respectively). Respondents commented that agroforestry systems would have a neutral effect on farm income, and would increase land stewardship. In some cases, interested landusers indicated a willingness to participate in agroforestry systems even though they anticipated increases in overhead and labour intensity; however, this was only true if they held land stewardship as a priority. Landusers were more concerned with the economic aspects of agroforestry, as a determinant to the future adoptability of particular practices. Age, gender, farm operation and farm size were not correlated with the adoption of agroforestry systems.The success of agroforestry programs on farms in the study area is largely dependent on the attitudes and willingness of landusers to participate in non-traditional agricultural systems.     

Agroforestry in the Bolivian Altiplano: evaluation of tree species and greenhouse growth of wheat on soils treated with tree leaves

Severe environmental problems encountered in the highlands of Bolivia may be remedied through the adoption of agroforestry systems, never before studied adequately in this region. As a first step, seven tree species were tested for growth, survival and health at two elevations in the Bolivian altiplano. Species responded variably with Buddleja coriacea Remy., Pinus radiata D. Don. and Eucalyptus globulus Labill. (at the higher elevation) and E. globulus, Baccharis spp., Robinia pseudoacacia L. and B. coriacea (at the lower elevation), displaying high survival, growth and health. In a related greenhouse study, grain yields of wheat planted in soils amended with incorporated foliage of B. coriacea, P. radiata and E. globulus increased three-fold (0.3 g·plant⁻¹ to >1.0 g·plant⁻¹) over grain yields in unamended soils (B. coriacea > P. radiata = E. globulus). Grain nitrogen (mg·plant⁻¹) increased equally in soils amended with P. radiata and B. coriacea foliage (18 mg N⋅plant⁻¹ to 20 mg·plant⁻¹) but decreased in soils amended with foliage of E. globulus (18 g·plant⁻¹ to 9 g·plant⁻¹). This revised version was published online in June 2006 with corrections to the Cover Date.     

Policies Affecting Forestry Entrepreneurship

Many demand and supply-side policies impede or foster forestry entrepreneurship. A study was conducted to consolidate existing knowledge on policies influencing forestry entrepreneurship in Finland, Norway, Japan, Australia, the Philippines and the USA, and to draw conclusions on these impeding and fostering factors. From the country studies it was difficult to find common structures on policies affecting forestry entrepreneurship. This is understandable because most policies in forestry are aimed at supporting sustainable forest management, wood production and ecological services of the forests rather than entrepreneurship as such. Despite the high variety of policies applied in the study countries, it can be concluded that strict public control on forests’ use and management potentially impedes forestry entrepreneurship. While these policies assist to correct market failure and to promote sustainability of forest management, they may also result into unnecessary and ineffective regulations that limit the opportunities for forestry entrepreneurship. A common feature promoting the demand for forestry entrepreneurship in some of the countries studied is the strong emphasis on forestry cooperatives, which were important institutions to support small-scale forestry entrepreneurship. In many study countries, different ad hoc programs are implemented to find new economic and entrepreneurial opportunities aside from the current use of wood and forests. Subsidies and tax incentives are commonly applied to reduce risks from making forestry investments or otherwise increase the economic return from timber production.     

Predation by invasive signal crayfish on early life stages of European barbel may be limited

1. To determine whether or not signal crayfish Pacifastacus leniusculus and native white‐clawed crayfish Austropotamobius pallipes prey on European barbel Barbus barbus eggs, interstitial free‐embryos and emergent larvae, experiments were undertaken in salmonid (substratum) incubators (six treatments, four controls) fitted with video recorders.
2. No corpses or remains of emergent barbel larvae or eggs, or parts thereof, were observed in any of the incubators containing buried eggs, and no emergent larvae showed any sign of attack. However, video evidence of a signal crayfish catching and consuming a barbel larva was obtained.
3. There were no statistically significant differences between white‐clawed and signal crayfish either in carapace length or weight at the beginning and end of the experiments. The conservation implications of these results are discussed.

     

Automated detection and tracking of marine mammals: A novel sonar tool for monitoring effects of marine industry

1. Many marine industries may pose acute risks to marine wildlife. For example, tidal turbines have the potential to injure or kill marine mammals through collisions with turbine blades. However, the quantification of collision risk is currently limited by a lack of suitable technologies to collect long‐term data on marine mammal behaviour around tidal turbines.
2. Sonar provides a potential means of tracking marine mammals around tidal turbines. However, its effectiveness for long‐term data collection is hindered by the large data volumes and the need for manual validation of detections. Therefore, the aim here was to develop and test automated classification algorithms for marine mammals in sonar data.
3. Data on the movements of harbour seals were collected in a tidally energetic environment using a high‐frequency multibeam sonar on a custom designed seabed‐mounted platform. The study area was monitored by observers to provide visual validation of seals and other targets detected by the sonar.
4. Sixty‐five confirmed seals and 96 other targets were detected by the sonar. Movement and shape parameters associated with each target were extracted and used to develop a series of classification algorithms. Kernel support vector machines were used to classify targets (seal vs. nonseal) and cross‐validation analyses were carried out to quantify classifier efficiency.
5. The best‐fit kernel support vector machine correctly classified all the confirmed seals but misclassified a small percentage of non‐seal targets (~8%) as seals. Shape and non‐spectral movement parameters were considered to be the most important in achieving successful classification.
6. Results indicate that sonar is an effective method for detecting and tracking seals in tidal environments, and the automated classification approach developed here provides a key tool that could be applied to collecting long‐term behavioural data around anthropogenic activities such as tidal turbines.