California, situated on the Pacific coast of the USA, is the third largest state of the United States in land area and most populous state. The 2009 population...
PlantLast Updated on 2014-10-28 12:04:37
A plant is any one of the vast number of organisms within the biological kingdom Plantae; in general, these species are considered of limited motility and generally manufacture their own food. They include a host of familiar organisms including trees, forbs, shrubs, grasses, vines, ferns, and mosses. Conventionally the term plant implies a taxon with characteristics of multicellularity, cell structure with walls containing cellulose, and organisms capable of photosynthesis. Modern classification schemes are driven by somewhat rigid categorizations inherent in DNA and common ancestry.
Throughout most of the history of science from Aristotle to Linnaeus and into the 20th century, species were divided into two kingdoms: animals and plants. Driven by DNA characterizations and other modern analysis, fungi and bacteria have now been removed to separate kingdoms; in particular,... More »
International Food Security Assessment: 2012-22Last Updated on 2014-10-26 16:56:26
Food security is estimated to improve slightly in 2012 as the number of food-insecure people in the 76 countries covered in this report declines from 814 million in 2011 to 802 million in 2012. The share of the population that is food insecure remains at 24 percent. Over the next decade, the share of the population that is food insecure is projected to decline from 24 percent in 2012 to 21 percent in 2022, but the number of food insecure people is projected to increase by 37 million. Regionally, food insecurity is projected to remain most severe in Sub-Saharan Africa. Food-insecure people are defined as those consuming less than the nutritional target of roughly 2,100 calories per day per person.
The U.S. Department of Agriculture's Economic Research Service (ERS) has, since the late 1970s, reported annually on food security in a number of developing countries. A key... More »
HerbicideLast Updated on 2014-10-26 16:45:24A herbicide is any of a number of chemical substances intended to kill vegetation. Since the vast majority of herbicides are non-selective in their lethal action, there may be widespread adverse ecological consequences from their use. These outcomes include not only organism death, but may involve mutagenic, developmental and carcinogenic effects to animals and plants.
Herbicides are in broad use for agriculture, golf courses, utility corridors, residential and other land uses. The earliest herbicides were inorganic chemical substances, although modern herbicides are dominated by organic compounds. Presently, there is massive application of chemical herbicides; in the USA alone 480 million kilograms are applied annually.
Widespread herbicide use beginning in the 1940s is responsible for numerous species extinctions, including birds, amphibians, fish and arthropods. In many cases,... More »
BiomassLast Updated on 2014-09-30 22:09:21
Biomass is a term in ecology for the mass of living organisms in a given ecosystem. Biomass can refer to the living stock of species in a given habitat, but can also refer to a harvested subset or to a decaying subset (especially in the case of forest floor detritus). Biomass may refer to the total mass of all species within the study area, and is thus sometimes called community biomass; but biomass may also refer to a taxonomic subset. Biomass can be expressed as the average mass per unit area or unit volume, or simply as the total mass in the community. Plants characteristically comprise the greatest part of the biomass of terrestrial system. In the animal kingdom, iIronically, the smallest creatures in an ecosystem typically represent the largest quantity of its biomass. It is important to note that the relative biomass species mix may change considerably from season... More »
Food Biodiversity Challenges From a Global PerspectiveLast Updated on 2014-07-25 14:03:15
Food collection or gathering has been an important part of human endeavors towards establishing civilization across the long history of human evolution. Humans have demonstrated their ingenuity in identifying and locating new and novel food sources located in their immediate surrounding and during their migration across the planet. Humans have become more successful than other species because of their better foraging abilities and coordinated group work in identifying and locating novel food sources over time. This trial and error approach has enabled humans over time to identify suitable food sources from their local environments. Over time, humans have identified more species that are edible or could be made edible using primitive to modern day recipes and cooking techniques. These long years of trial and errors have generated a wide range of food sources for... More »
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