Landscape ecological concepts in planning: review of recent developments

Landscape Ecology - Landscape ecology as an interdisciplinary science has great potential to inform landscape planning, an integrated, collaborative practice on a regional scale. It is commonly...     

Metal ions restore the proteolytic resistance of denatured conglutin gamma, a lupin seed glycoprotein, by promoting its refolding

The susceptibility to trypsin of conglutin gamma, a lupin seed glycoprotein affected by this enzyme only when in a non-native conformation, was used to study the effect of Zn(2+) and other metal ions on the structural dynamics of the protein. When acid-treated trypsin-susceptible conglutin gamma was incubated at neutral pH in the presence of Zn(2+), it became resistant to tryptic attack, contrary to the protein treated in the absence of Zn(2+). The time course of this refolding event has been quantitatively evaluated by SDS-PAGE. Amino acid sequencing of the major polypeptide fragments, produced by trypsin before completion of the refolding process, indicated that only a few cleavable bonds were accessible to the enzyme. This suggested that the presence of metal ions affected the pathway of degradation of the protein, by inducing its folding. Among the other metal ions tested, Ni(2+) also promoted the adoption of a trypsin-resistant conformation of conglutin gamma, whereas Mn(2+) and Ca(2+) had only much lower effects. The relevance of these findings for a deeper understanding of the in vivo degradation of plant food proteins and how it is affected by metal ions are discussed.     

Invertebrate diversity associated with a shallow rhodolith bed in the Mediterranean Sea (Mar Piccolo of Taranto,south-east Italy)

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Relation of peel damage in citrus fruit to wind climate in orchard and its control

Peel damage originated by wind is the main abiotic cause of citrus fruit discards for export in Uruguay. Natural windbreaks such as Eucalyptus and Casuarinas have not been effective in reducing it. This research was carried out during three years in a citrus orchard situated in the coastal plain of Uruguay (35° SL). The purpose of this work was to study wind climate inside the orchard, fruit seasonal sensitivity, basal leaf effect on the onset and evolution of peel damage, and the efficiency of artificial windbreaks to reduce fruit discard of ‘Ellendale’ tangor. Average wind velocity in the orchard did not exceed 5 m s⁻¹. First peel scars were evident two weeks after petal fall and damaged fruit percentage importantly increased during the first stage of fruit growth. Low energy vortexes caused almost permanent friction between basal leaves and the developing fruitlets growing in their axil. Removal of the basal leaf decreased significantly wind damaged fruit. Natural wind flow modification through the use of semi-porous artificial windbreak nets (5 cm by 10 cm mesh) modified low energy vortexes and increased significantly the percentage of export quality fruit. We conclude that this type of net is more efficient than natural windbreaks or classical nets to reduce wind damage in citrus fruit.     

Rearing experiences of the polychaete Sabella spallanzanii in the Gulf of Taranto (Mediterranean Sea,Italy)

In order to utilize the biomass of the polychaete Sabella spallanzanii Gmelin as a dietary supplement for fish nourishment, we conducted some experiences of rearing this worm in the Mediterranean Sea. A preliminary study on the growth of this species on suspended plastic nets was conducted in two sites of the Apulian coast with different trophic features. Data for the first 12 months show that S. spallanzanii reared in eutrophic conditions grows producing a biomass higher than the natural population. The acquired experience was afterward tested in a pilot plant located in the Mar Piccolo of Taranto, a eutrophic area where polychaetes were co-cultured with Mytilus galloprovincialis within a long-line farm. The slight mortality recorded during the first 2 months and quite negligible after 4 months, the high increase in volume and biomass of the reared polychaetes, especially at high density (70 individuals for each net), demonstrated the advantage of rearing S. spallanzanii in the pilot plant with low cost of production and high profit. If the acquired technology is applied to a medium farm containing up to 400 sectors, the biomass produced indeed might reach about 1.36 tons/year. In conclusion, on the basis of our results, we demonstrated the possibility to obtain high-value worm biomass coupled to mussel biomass in a completely non-fed culturing system without increasing, but presumably reducing the environmental impact due to mussel farming.     

Experimental co-culture of low food-chain organisms, Sabella spallanzanii (Polychaeta, Sabellidae) and Cladophora prolifera (Chlorophyta, Cladophorales), in Porto Cesareo area (Mediterranean Sea)

The filter feeder polychaete Sabella spallanzanii (Gmelin) was co‐cultured with the green seaweed Cladophora prolifera (Roth.) Kunz, in an off‐shore experimental system. Both species have previously been experimented as bioremediator organisms for waste treatment deriving from aquaculture farms and can have a high economic value as a byproduct of polyculture. The present experiment has been conducted in an area 2 miles off the coast of Porto Cesareo (Ionian sea, Southern Italy). The growth was followed in some modules anchored to the bottom at two different depths (15 and 25 m depth). The results indicate differences among replicates located at different depths. Both organisms show a faster growth at the shallower levels. Within this level, polychaetes reached a mean biomass of 860±74 mg dw (average±SE) per worm, 30 times larger than that of the starting point, after a standstill in the first period, probably due to the manipulation activities. The major growth has been recorded during the winter. Algae have shown an increase of 34 g ww month⁻¹ (average±SE) in the shallower levels vs. only 11 g ww month⁻¹ (average±SE) in the deeper levels. The RGR calculated after 60 days was 115% in the shallower levels vs. about 60% in the deeper ones. A considerable decrease in growth rate was observed during the last period; this was probably due to the presence of increasing fouling community on the rearing cages surely affecting the light intensity.