The multi-disciplinary evaluation of a national agri-environment scheme

With an increasing amount of public funds being spent on agri-environmental schemes effective methods have to be developed to evaluate them. As many schemes have multiple objectives there is a need for a multi-disciplinary approach to any evaluation. A method was developed to assess the degree to which ecological, landscape, historical and access objectives for the Countryside Stewardship Scheme (CSS) in England have been met. The method used a sample of 484 agreements for which data were collected from surveys, a desk study and an interview with the agreement holder. These data were then evaluated by an expert team of an ecologist, landscape architect, landscape historian, and a social scientist specializing in rural affairs. The team were subsequently brought together with a Chair to discuss their findings for each agreement, allocating scores for each of five criteria: agreement negotiation; appropriateness, environmental effectiveness, compliance and side effects. The additionality that each agreement was likely to provide was also assessed. The results of this process suggest that in the majority of cases the CSS agreements should maintain or enhance the environment in terms of ecology, landscape, and landscape history and increase public enjoyment of the countryside. Thirty-six percent of agreements showed high additionality and 38% medium additionality which demonstrates that the CSS is likely to provide a benefit to society. Agreement negotiation, predicted environmental effectiveness and predicted compliance all improved significantly over the period 1996-98. Recommendations made from this project have been implemented by the Government department to improve the CSS. The multi-disciplinary method was successful and, with further development, could be used for assessment of any agri-environment scheme, or potentially any conservation project or broader 'rural development' scheme encompassing environmental, economic and social objectives. A key to success is the need for the criteria to be tailored for the project concerned and clearly established at the beginning.     

The effect of clock-shift on the initial orientation of wild rock doves (<Emphasis Type="Italic">Columba l. livia</Emphasis>)

Previous experiments on wild rock doves ( Columba l. livia Gmelin) released within their familiar area revealed an evident effect of fast-shifting, although shifted doves, but not controls, tended to orient homeward. Such an outcome suggested a possible influence of the release time per se on the directional choices of the tested doves. In the present study, this hypothesis was investigated by comparing the orientation of slow-shifted birds to that of two control groups released at different times of the day. As would be expected if doves make use of a time-compensated sun compass, the bearings of shifted birds were deflected clockwise with respect to controls. The time of release itself seemed to influence only the scatter of the vanishing bearings of controls. These findings testify to the substantial similarity of clock-shift effects on the initial orientation of rock doves to those on homing pigeons released from familiar sites.     

Insect fauna associated with sugarcane plantations in Sri Lanka

A survey conducted over 13 years (1986-1999) in sugarcane plantations in Sri Lanka to identify insects associated with sugarcane recorded a total of 103 insect species comprising Coleoptera (31 spp.), Dictyoptera (2 spp.), Diptera (5 spp.), 12 Heteroptera (12 spp.), Homoptera (18 spp.), Hymenoptera (7 spp.), Isoptera (3 spp.), Lepidoptera (13 spp.), Orthoptera (9 spp.), and one species each of Thysanoptera, Nuroptera and Trichoptera. Among them were forty-six species of sugarcane pests. In addition, 27 species of natural enemies of sugarcane pests belonging to the orders Coleoptera, Diptera and Hymenoptera were identified Epiricania melanoleuca (Fletcher) introduced into Sri Lanka from Pakistan in 1991 for the control of the sugarcane planthopper was also recorded. Five new pest species previously not recorded from sugarcane in Sri Lanka have been identified.     

Insecticidal activity of the plant Phyllanthus amarus against Tribolium castaneum

The plant Phyllanthus amarus is used as folk medicine since the year 1800 and has been established for its important medicinal properties particularly for liver ailments. The present communication explores the insecticidal activity of ethanolic extract of aerial and root parts of this plant against stored grain pest Tribolium castaneum. LC 50 values of ethanolic aerial part were 895.77, 473.91, 279.89 and 260.85 microg/cm2, while 512.62, 376.96, 248.88 and 209.79 microg/cm2 for ethanolic root part at the exposure of 3, 5, 7, 9 and 11 days respectively. Ethanolic root extract possessed significant insecticidal activity against T. castaneum.     

Differential feeding of worker larvae affects caste characters in the Cape honeybee,<Emphasis Type="Italic"> Apis mellifera capensis</Emphasis>

Sections of brood from colonies of the Cape honeybee ( Apis mellifera capensis), the African honeybee ( A. m. scutellata), and hybrid bees of the two races were exchanged between colonies to study the effect of different brood-origin/nurse-bee combinations on development of caste characters. When Cape larvae were raised by African workers the amount of food provided almost doubled in comparison with Cape larvae reared by their own workers. In contrast, African larvae raised by Cape workers were provided with only half the amount they received from their own workers. After the bees emerged, we found a large degree of plasticity in characters related to caste differentiation, which corresponded closely to the amount of food provided. Super-fed Cape bees had enlarged spermathecae, were heavier than normal workers and developed more rapidly, and had reduced pollen combs, all typical for a more queen-like condition. Ovariole numbers did not appear to be enhanced by additional feeding. Cape bees that behave as social parasites in African bee colonies were most queen-like in the characters studied, albeit within the range that was found for Cape bees from normal colonies, suggesting within-colony selection for characters that enhance reproduction.Communicated by R. Page     

A statistical approach to estimate O3 uptake of ponderosa pine in a mediterranean climate

In highly polluted sites, stomatal behavior is sluggish with respect to light, vapor pressure deficit, and internal CO2 concentration (Ci) and poorly described by existing models. Statistical models were developed to estimate stomatal conductance (gs) of 40-year-old ponderosa pine at three sites differing in pollutant exposure for the purpose of calculating O3 uptake. Gs was estimated using julian day, hour of day, pre-dawn xylem potential and photosynthetic photon flux density (PPFD). The median difference between estimated and observed field gs did not exceed 10 mmol H2O m(-2) s(-1), and estimated gs within 95% confidence intervals. 03 uptake was calculated from hourly estimated gs, hourly O3 concentration, and a constant to correct for the difference in diffusivity between water vapor and 03. The simulation model TREGRO was also used to calculate the cumulative 03 uptake at all three sites. 03 uptake estimated by the statistical model was higher than that simulated by TREGRO because gas exchange rates were proportionally higher. O3 exposure and uptake were significantly correlated (r2>0.92), because O3 exposure and gs were highly correlated in both statistical and simulation models.     

Soil quality in New Zealand: policy and the science response

Soil depletion and degradation have been increasingly recognized as important environmental issues in many parts of the world. Over the last decade a number of political and legislative measures have been introduced to encourage and enforce sustainable soil management in New Zealand. Application of the new legislation has highlighted gaps in our knowledge of soil quality and a lack of scientific methods to assess and monitor soil quality. This paper describes the legislative measures and outlines the sdentific response to the needs of regulatory agencies responsible for maintaining environmental quality. The research recommended a set of indicators to assess soil quality. Each soil quality attribute has an associated "target range" defining the acceptable value for the attribute. The paper also discusses the communication of results to end-users, including the development of a computerized assessment tool. The legislative measures and scientific response have fostered a closer relationship between the policy and science communities, leading to more well-focused research, but greater collaboration is still required.     

Rhizosphere acidification and cadmium uptake by strawberry clover

Strawberry clover (Trifolium fragiferum L.) is a hardy legume found in indigenous or introduced populations throughout the world. Tolerance to saline and alkaline soils, flooding, and heavy metals make it a good prospect for reclamation projects. The research, described here, was conducted to: (i) characterize the morphological variation in plants from available seed sources, (ii) evaluate cadmium uptake and tolerances over a wide range of morphological variants, and (iii) elucidate the variability in the effects of roots on rhizosphere pH and the relationship to cadmium uptake. Seeds from selected accessions were planted in the greenhouse for comparison of morphological variation. The accessions examined had a mean height of 10.7+/-7 cm. Accessions 254916 and 237925 are tall with high rhizosphere pH values and might be useful in phytoremediation. Strawberry clover accessions were also grown hydroponically to examine differences in cadmium uptake. The ability of strawberry clover roots to change rhizosphere pH and take up cadmium was examined using culture tubes containing nutrient agar, a moderate level of cadmium, and a pH indicator dye. The results provided evidence for a negative correlation between rhizosphere pH and cadmium uptake.     

Real-time, high-resolution quantitative measurement of multiple soil gas emissions: selected ion flow tube mass spectrometry

A new technique is presented for the rapid, high-resolution identification and quantification of multiple trace gases above soils, at concentrations down to 0.01 microL L(-1) (10 ppb). The technique, selected ion flow tube mass spectrometry (SIFT-MS), utilizes chemical ionization reagent ions that react with trace gases but not with the major air components (N2, O2, Ar, CO2). This allows the real-time measurement of multiple trace gases without the need for preconcentration, trapping, or chromatographic separation. The technique is demonstrated by monitoring the emission of ammonia and nitric oxide, and the search for volatile organics, above containerized soil samples treated with synthetic cattle urine. In this model system, NH3 emissions peaked after 24 h at 2000 nmol m(-2) s(-1) and integrated to approximately 7% of the urea N applied, while NO emissions peaked about 25 d after urine addition at approximately 140 nmol m(-2) s(-1) and integrated to approximately 10% of the applied urea N. The monitoring of organics along with NH3 and NO was demonstrated in soils treated with synthetic urine, pyridine, and dimethylamine. No emission of volatile nitrogen organics from the urine treatments was observed at levels >0.01% of the applied nitrogen. The SIFT method allows the simultaneous in situ measurement of multiple gas components with a high spatial resolution of < 10 cm and time resolution <20 s. These capabilities allow, for example, identification of emission hotspots, and measurement of localized and rapid variations above agricultural and contaminated soils, as well as integrated emissions over longer periods.     

Three-dimensional nickel ion transport through porous media using magnetic resonance imaging

The transport of Ni2+ ions in a column, filled with porous media, was observed in three dimensions and time by magnetic resonance imaging (MRI) in a clinical scanner. For porous media we used glass beads or quartz sand in a saturated continuous flow mode. The magnetic moment of Ni2+ decreased the T1 relaxation time of 1H in aqueous solution. This concentration-dependent effect was used by a fast low angle shot (FLASH) MRI sequence for imaging the concentration of the dissolved ions. Since Ni2+ behaves as a conservative tracer under the chosen conditions, the tracer motion was representative for the water flow in the porous medium. Currently, we can achieve an isotropic spatial resolution of 1.5 mm and a temporal resolution of 170 s. The transport observation gives direct access to hydraulic flow properties of the porous media. The fluid flow velocity field was calculated by a fronttracking method and the statistical properties of the velocities were investigated. We also compared the experimental data with the three-dimensional particle tracking model PARTRACE, which uses the experimental flow field as input.