Tradeoffs and synergies in wetland multifunctionality: A scaling issue

Wetland area in agricultural landscapes has been heavily reduced to gain land for crop production, but in recent years there is increased societal recognition of the negative consequences from wetland loss on nutrient retention, biodiversity and a range of other benefits to humans. The current trend is therefore to re-establish wetlands, often with an aim to achieve the simultaneous delivery of multiple ecosystem services, i.e., multifunctionality. Here we review the literature on key objectives used to motivate wetland re-establishment in temperate agricultural landscapes (provision of flow regulation, nutrient retention, climate mitigation, biodiversity conservation and cultural ecosystem services), and their relationships to environmental properties, in order to identify potential for tradeoffs and synergies concerning the development of multifunctional wetlands. Through this process, we find that there is a need for a change in scale from a focus on single wetlands to wetlandscapes (multiple neighboring wetlands including their catchments and surrounding landscape features) if multiple societal and environmental goals are to be achieved. Finally, we discuss the key factors to be considered when planning for re-establishment of wetlands that can support achievement of a wide range of objectives at the landscape scale.

Straight ileoanal anastomosis after longitudinal strip myectomy in the swine model

In an attempt to improve the function of the straight ileoanal anastomosis, an experimental study was performed using the swine model. The terminal ileum was altered by completely removing two longitudinal strips of muscle prior to performing a straight ileoanal anastomosis. The intent of the study was to determine whether muscle stripping was technically possible and whether bowel thus treated would remain viable to passively form a pelvic reservoir. The length of time required for formation of the reservoir was noted. All animals survived the procedure to allow evaluation. The muscle stripping was not difficult to perform. Viability was not a problem since the myectomy animals thrived well and demonstrated continence, weight gain, and reservoir formation. The results are encouraging. It appears that strips of muscularis propria can be removed from the terminal ileum without jeopardizing its viability. This seems to disrupt sufficiently the tonus of the bowel to allow better function of the straight ileoanal anastomosis through formation of a passive pelvic reservoir within a month's time in the swine model, and it may have application in the human.

Effects of magnetic field exposure on fertilization success in rainbow trout, Salmo gairdneri

The sensitivity of trout ova and sperm to 1-T magnetic fields was investigated. It was determined that 1) overall test results combining seven independent Z-statistics demonstrated a significant (alpha less than 0.0001) enhancement of fertilization when ova alone were exposed to the magnetic field prior to fertilization; 2) similarly, overall test results combining Z-statistics from eight independent experiments indicated a significant (alpha less than 0.0004) enhancement when sperm alone were exposed; and 3) statistical analysis of nine independent experiments confirmed enhanced fertilization (alpha less than 0.0001) when both ova and sperm were exposed to the magnetic field prior to fertilization. Although these data indicated that both ova and sperm were sensitive to magnetic fields, simultaneous exposure of both gametes did not have a greater total effect on fertilization rate than the sum of their individual effects.

Suppression of the Primary Immune Response in Rainbow Trout, Salmo gairdneri, Sublethally Exposed to Tritiated Water During Embryogenesis

Antibody synthesis, in response to vaccination with a 0.1-ml (1.8 × 108 cells/ml) intraperitoneally injected, heat-killed strain of Flexibacter columnaris, was employed to investigate the effect of tritium irradiation (0, 0.04, 0.4, 4.0, 40 rads total dose for 20 days during embryogenesis) on development of the primary immune response in 5-mo rainbow trout, Salmo gairdneri, reared under essentially pathogen-free conditions. Specific agglutinins to F. columnaris, determined 1-wk pre vaccination, and 3, 5, 7, 9, and 11 wk postvaccination increased rapidly in both control and irradiated fish following vaccination. Agglutinin levels in irradiated fish were suppressed to 50% of control levels at 40 rads during the 9th wk, and 50% of control levels at 4.0 rads during the 11th wk. Electrophoretic separation of serum proteins of both control and irradiated–vaccinated fish demonstrated four major protein fractions. Densitometry analyses demonstrated that fraction IV increased significantly in percent of total protein following antigenic stimulation, suggesting that fraction IV represents the specific humoral antibody to F. columnaris. The relative percent of total protein contained in fraction IV was significantly reduced in irradiated–vaccinated fish. Key words: antibody synthesis, agglutination assay, vaccination, Flexibacter columnaris, tritium, Salmo gairdneri, electrophoresis, serum protein, densitometry, primary immune response