Dissolved organic carbonDissolved organic carbon (DOC) is the fraction of organic carbon operationally defined as that which can pass through a filter with a pore size typically between 0.22 and 0.7 micrometers. The fraction remaining on the filter is called particulate organic carbon (POC). Dissolved organic matter (DOM) is a closely related term often used interchangeably with DOC. While DOC refers specifically to the mass of carbon in the dissolved organic material, DOM refers to the total mass of the dissolved organic matter.
SpeciesIn biology, a species (: species) is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour, or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined.
Organic compoundIn chemistry, many authors consider an organic compound to be any chemical compound that contains carbon-hydrogen or carbon-carbon bonds, however, some authors consider an organic compound to be any chemical compound that contains carbon. The definition of "organic" versus "inorganic" varies from author to author, and is a topic of debate. For example, methane () is considered organic, but whether some other carbon-containing compounds are organic or inorganic varies from author to author, for example halides of carbon without carbon-hydrogen and carbon-carbon bonds (e.
Reaction rateThe reaction rate or rate of reaction is the speed at which a chemical reaction takes place, defined as proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time. Reaction rates can vary dramatically. For example, the oxidative rusting of iron under Earth's atmosphere is a slow reaction that can take many years, but the combustion of cellulose in a fire is a reaction that takes place in fractions of a second.
Invasive speciesAn invasive or alien species is an introduced species to an environment that becomes overpopulated and harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its food web - for example, the purple sea urchin (Strongylocentrotus purpuratus) which has decimated kelp forests along the northern California coast due to overharvesting of its natural predator, the California sea otter (Enhydra lutris).
