Marine crops

Five major biomass feedstocks were considered in this analysis — low moisture plants, high moisture plants, woody crops, manure, and marine crops. For each of these categories. Mission Analysis Final Report, Volume III, describes a set of resource curves, corresponding to the years 1975, 1985, 2000, and 2020 — the time frame of the analysis. Prices for the intervening years are found by interpolation within the computer model. 

Based only on market penetration projections, processes that appear to offer minor future contributions include marine crops, catalytic liquefaction, and fermentation to produce ethanol. Missions that appear to have greater near-term commercialization potential include ... 

The other global environmental problem, stratospheric ozone depletion, was less controversial and more imminent. The U.S. Senate Committee Report supporting the Clean Air Act Amendments of 1990 states, Destruction of the ozone layer is caused primarily by the release into the atmosphere of chlorofluorocarbons (CFCs) and similar manufactured substances—persistent chemicals that rise into the stratosphere where they catalyze the destruction of stratospheric ozone. A decrease in stratospheric ozone will allow more ultraviolet (UV) radiation to reach Earth, resulting in increased rates of disease in humans, including increased incidence of skin cancer, cataracts, and, potentially, suppression of the immune system. Increased UV radiation has also been shown to damage crops and marine resources."... 

The carotenoids are the most widespread group of pigments in nature, with an estimated yield of 100 million tonnes per annum. They are present in all photosynthetic organisms and responsible for most of the yellow to red colours of fruits and flowers. The characteristic colours of many birds, insects and marine invertebrates are also due to the presence of carotenoids, which have originated in the diet. Animals are unable to synthesise carotenoids de novo, and so rely upon the diet as the source of these compounds. Carotenoids found in the human diet are primarily derived from crop plants, where the carotenoids are located in roots, leaves, shoots, seeds, fruit and flowers. To a lesser extent, carotenoids are also ingested from eggs, poultry and fish. Commercially, carotenoids are used as food colourants and in nutritional supplements (Table 13.1). Over recent years there has been considerable... 

Macias LA, Varela RM, Torres A, Mohnillo JMG (1993) Potential allelopathic guaianolides from cultivar sunflower leaves, var. SH-222. Phytochemistry 34 669-674 Macias LA, Molinillo JMG, Galindo JCG, Varela RM, Simonet AM, Castellano D (2001) The use of allelopathic studies in search for natural herbicides. J Crop Prod 4 237-256 Macias AL, Marin D, Oliveros-Bastidas A, Varela RM, Simonet AM, Carrera C, Molinillo JM (2003) Allelopathy as a new strategy for sustainable ecosystems development. Biol Sci Space 17 18-23... 

There are also natural geochemical anomalies where soils are enriched by cadmium, for example, in the central parts of Sweden. Here the cultivation of crops accumulating cadmium (grains, potato, some grasses) is not recommended. In the coastal marine areas the cadmium mobility in soils is stimulated by its complexation with chlorine. 

Xylan occurs in practically all land plants and is said to be present in some marine algae.6 In both wide botanical distribution and abundance in nature it closely follows cellulose and starch. It is most abundant in annual crops, particularly in agricultural residues such as corn cobs, corn stalks, grain hulls and stems. Here it occurs in amounts ranging from 15 to 30%. Hard woods contain 20 to 25% xylan while soft woods contain 7 to 12 %. Spring wood has more pentosan than summer wood. 7 Low strength vegetable fibers of commerce such as jute, sisal, Manila... 

Cereals can yield around 1500-3000 litres of gasoline equivalent (lge)/ha sugarcane, 3000-6000 lge/ha sugarheet, 2000-4000 lge/ha vegetable oil crops, 700-1300 litres of diesel equivalent (lde)/ha and palm oil, 2500-3000 lde/ha (IEA, 2007). In addition, there are novel biofuel production processes under development, for example biodiesel from marine algae, which are claimed to have a 15 times higher yield per ha than rapeseed. 

In order to reconstruct human diet from bone tissue, direct isotopic analysis of animal and plant remains from the same archaeological context is the most reliable way to detect isotopic shifts involving the whole ecosystem due to environmental variation. Since this is often impossible for the lack of these control samples, we have explored the use of 8I80 to assess the environmentally induced variation in 8I3C and 8ISN values from collagen and apatite, and assess the dietary information they represent. This can be done assuming a scarce nutritional role of marine resources and the absence of C4 crops, as seems to be the case in the western Mediterranean and specifically in the Sardinian Neolithic and Bronze Age. 

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