Search results
Results From The WOW.Com Content Network
Gross primary production (GPP) is the amount of chemical energy, typically expressed as carbon biomass, that primary producers create in a given length of time.Some fraction of this fixed energy is used by primary producers for cellular respiration and maintenance of existing tissues (i.e., "growth respiration" and "maintenance respiration").
Chemical & Engineering News publishes an annual list of the world's largest chemical producers by sales, excluding formulated products such as pharmaceutical drugs and coatings. [1] In 2018, sales of the top fifty companies amounted to US$ 951,000,000,000, an increase of 11.8% compared to the top fifty producers of 2017. [ 2 ]
Some marine primary producers are specialised bacteria and archaea which are chemotrophs, making their own food by gathering around hydrothermal vents and cold seeps and using chemosynthesis. However, most marine primary production comes from organisms which use photosynthesis on the carbon dioxide dissolved in the water.
Lichens located in tundra climates are an exceptional example of a primary producer that, by mutualistic symbiosis, combines photosynthesis by algae (or additionally nitrogen fixation by cyanobacteria) with the protection of a decomposer fungus. As there are many examples of primary producers, two dominant types are coral and one of the many ...
As primary consumers, zooplankton are the crucial link between the primary producers (mainly phytoplankton) and the rest of the marine food web (secondary consumers); [191] the ocean's primary producers are mostly tiny phytoplankton which have r-strategist traits of growing and reproducing rapidly, so a small mass can have a fast rate of ...
Examples of these activities include habitat modification, freshwater consumption, an increase in nutrients due to fertilizers, and many others. [30] Increased nutrients can stimulate an algal bloom in waterbodies, increasing primary production but making the ecosystem less stable. [ 31 ]
Food chain in a Swedish lake. Osprey feed on northern pike, which in turn feed on perch which eat bleak which eat crustaceans.. A food chain is a linear network of links in a food web, often starting with an autotroph (such as grass or algae), also called a producer, and typically ending at an apex predator (such as grizzly bears or killer whales), detritivore (such as earthworms and woodlice ...
The following table lists the largest biotechnology and pharmaceutical companies ranked by revenue in billion USD. The change column indicates the company's relative position in this list compared to its relative position in the preceding year; i.e., an increase would be moving closer to rank 1 and vice versa.