Man and other introduced organisms

Man's tremendously increased migratory potention, coupled with his ability to transport any material, causes ecological revolutions on most islands of this world–Fernandina and most smaller islands of the Galapagos being fortunate exceptions to that rule. It is proposed to make distinctions between species colonizing the Galapagos We can distinguish between those immigrant species which do not profit from man as a transport medium (independent immigrants) and those who do depend on him (man-dependent immigrants). These immigrants, in turn, may or may not be able to settle and these settlers may either gain a footing with or without depending on man's direct or indirect influence on the habitat (non-settlers, primary resource-using settlers, and secondary resource-using settlers). Introduced species represent a terrible attack on the biotic uniqueness of the Galapagos ecosystems. However, it is proposed to make better use of the scientific value of these introductions. For example, a case of selective impact of an introduced on an indigenous species was investigated: lava lizards of the genus Tropidurus seem to be more wary of moving objects on islands where cats have been introduced by man than on islands free of cats.
Under the peculiar Galapagos conditions it may turn out that science's most difficult and important task is to investigate and interpret man's role in such places.     

Interactions of fungi with other organisms

Living organisms establish complex networks of mutualistic and antagonistic interactions in nature, which impact strongly on their own survival and on the stability of the whole population. Fungi, in particular, can shape natural as well as man-managed ecosystems due to their ubiquitous occurrence and the range of interactions they establish with plants, animals and other microbes. This review describes some examples of mutualistic and antagonistic fungal interactions that are of particular interest for their ecological role, or because they can be exploited by man to improve plant health and/or productivity in sustainable agriculture and forestry.     

Laticiferous plants of economic importance

Gutta-gums figure prominently in international trade. For more than 100 years the United States has been, and continues to be, the principal cousumer of these raw materials. Trade reports issued by the U. S. Department of Commerce indicate that during 1960 approximately 11,717,000 pounds of these forest products, with an aggregate value of $6,536,792, were imported, mostly from Malaysia, Central America, and northern South America. These commodities are still furnished mainly by “wild” trees. Plantation development has been limited to small-scale propagation of guttapercha (Palaquium gutta Burck) in Indonesia and Malaya and recently of chilte (Cnidoscolus spp.) in western Mexico. In comparison with Hevea brasiliensis (Willd. ex Adr. Juss.) Muell. Arg., Castilla elastica Cerv., and other species of rubber, relatively little has been published on the sources of gutta-gums.     

稻鸭共育生态效应及经济效益

稻鸭共育是一项无须使用除草剂和施用较少农药的低成本生态农业技术。通常,20d左右大的鸭子按225只.hm-2放入移栽不久的稻田。由于取食和活动,它们能够帮助控制田间杂草、虫害、甚至病害,并且对水稻生长发育、土壤理化性状、水体溶氧量和微生物等产生一定的影响。本文概述了稻鸭共育的生态效应和经济效益的研究进展,并指出应加强在精确施肥和水稻后期病虫害防治等方面的深入研究。     

Production,harvesting, processing,utilization and economic importance of oats

Oats constitute an important feed grain crop in the United States and many other countries. World production in pounds averages one- third that of wheat and two- fifths that of rice or corn. The United States and Canada produce nearly half of the world crop. Oats are utilized primarily as feed for domestic animals. Although their bone- and muscle- building ingredients and other nutrient values are well known, less than five percent of the world crop is used as human food.     

Trees and their economic importance

The biological and logical meaning of trees, which are one of the important woody plants of our ecosystem, are reviewed in this article. Trees are mostly used for timber purposes, but in the present article the utility of trees with respect to their importance in restoring, reclaiming and rejuvenating denuded and disturbed soils, their ecological, ecodevelopmental and environmental use, and their educational and recreational value in gardening, landscaping and bioesthetic planning is described. In addition, the importance of trees is discussed with reference to their value as a source of sustenance: food, sugars, starches, spices and condiments, beverages, fumitories, masticatories and narcotics, medicines, essential oils, fatty oils and vegetable fats, waxes, soap substitutes, vegetable ivory, fodder, fuel, bioenergy or biofuel, fertilizers, fiber, pulp and paper, tannins, dyes, rubber and other latex products, gums, resins and cork. Lastly, the food plants of mulberry and non-mulberry silkworms, which feed on the leaves of many forest trees, are mentioned.     

Laticiferous plants of economic importance II

The genus Cnidoscolus, of the Spurge Family (Euphorbiaceae), is a homogeneous group of herbs. shrubs or small to medium-sized trees indigenous to tropical America, with a few species extending to subtropical and temperate regions. The generic name, derived from the Greek meaning nettle and spine, alludes to the painfully stinging hairs frequently present. Two species of chilte growing in west-central Mexico are now utilized in industry as a source of gutta-like material with high hydrocarbon and resin content.     

Biophysical and economic water productivity of dual-purpose cattle farming

This study analyzes key factors influencing water productivity in cattle rearing, particularly in contexts characterized by water scarcity. This was done through year-round monitoring of on-farm practices within five smallholder farms located in the Saïss area (northern Morocco). The on-farm monitoring protocol consisted of characterizing: (i) volumes of water used for fodder production and distinguished by source (rainfall, surface irrigation and groundwater), (ii) virtual water contained in off-farm feed resources, (iii) total forage biomass production, (iv) dietary rations fed to lactating cows and their calves and (v) milk output and live weight gain. Findings reveal a mean water footprint of 1.62±0.81 and 8.44±1.09 m³/kg of milk and of live weight gain, respectively. Groundwater represented only 13.1% and 2.2% of the total water used to get milk and live weight gain, respectively, while rainfall represented 53.0% and 48.1% of the total water for milk and live weight gain, respectively. The remaining water volumes used came from surface irrigation water (7.4% for milk and 4.0% for live weight gain) and from virtual water (26.5% for milk and 44.7% for live weight gain). The results also revealed a relatively small gross margin per m³ of water used by the herd, not exceeding an average value of US $ 0.05, when considering both milk and live weight. Given the large variability in farm performances, which affect water productivity in cattle rearing throughout the production process, we highlight the potential for introducing a series of interventions that are aimed at saving water, while concurrently improving efficiency in milk production and live weight gain. These interventions should target the chain of production functions that are implemented throughout the process of water productivity in cattle rearing. Moreover, these interventions are of particular importance given our findings that livestock production depends largely upon rainfall, rather than groundwater, in an area afflicted with sustained droughts, overexploitation of groundwater resources and growing water scarcity.     

Disruption of bacterial quorum sensing by other organisms

Higher plants and algae produce compounds that mimic quorum sensing: signals used by bacteria to regulate the expression of many genes and behaviors. Similarly, various bacteria can stimulate, inhibit or inactivate quorum sensing in other bacteria. These discoveries offer new opportunities to manipulate bacterial quorum sensing in applications relevant to medicine, agriculture and the environment.     

Name changes in fungi of economic importance

International Commission on the Taxonomy of Fungi (ICTF)     

Interactions between mycorrhizal fungi and other soil organisms

Mycorrhizal fungi interact with a wide range of other soil organisms, in the root, in the rhizosphere and in the bulk soil. These interactions may be inhibitory or stimulatory; some are clearly competitive, others may be mutualistic. Effects can be seen at all stages of the mycorrhizal fungal life-cycle, from spore population dynamics (predation, dispersal and germination) through root colonization to external hyphal growth. Two areas that seem likely to be of particular importance to the functioning of the symbiosis are the role of bacteria in promoting mycorrhiza formation and of soil animals in grazing the external mycelium. Mycorrhizal fungi also modify the interactions of plants with other soil organisms, both pathogens, such as root-inhabiting nematodes and fungi, and mutualists, notably nitrogen-fixing bacteria. These interactions are probably important both in natural ecosystems, where pathogens are increasingly recognized as playing controlling roles, and in agricultural systems, where mycorrhizas may be valuable in designing integrated systems of pest control and growth stimulation.     

The glycomes of Caenorhabditis elegans and other model organisms

There is no doubt that the immense amount of information that is being generated by the initial sequencing and secondary interrogation of various genomes will change the face of glycobiological research. However, a major area of concern is that detailed structural knowledge of the ultimate products of genes that are identified as being involved in glycoconjugate biosynthesis is still limited. This is illustrated clearly by the nematode worm Caenorhabditis elegans, which was the first multicellular organism to have its entire genome sequenced. To date, only limited structural data on the glycosylated molecules of this organism have been reported. Our laboratory is addressing this problem by performing detailed MS structural characterization of the N-linked glycans of C. elegans; high-mannose structures dominate, with only minor amounts of complex-type structures. Novel, highly fucosylated truncated structures are also present which are difucosylated on the proximal N-acetylglucosamine of the chitobiose core as well as containing unusual Fuc alpha 1-2 Gal 1-2 Man as peripheral structures. The implications of these results in terms of the identification of ligands for genomically predicted lectins and potential glycosyltransferases are discussed in this chapter. Current knowledge on the glycomes of other model organisms such as Dictyostelium discoideum, Saccharomyces cerevisiae and Drosophila melanogaster is also discussed briefly.