Robert Paine was the first biologist to use the term keystone species in the 1960s. He was studying food webs in the rocky, intertidal pools in the Pacific Northwest. At one of his study sites, the dominant organisms in the tidal pools were mussels, barnacles, whelks, and a species of starfish known as Pisaster ochraceus . To examine the relationship between these species, Paine set up an experiment. In one area, he removed all the starfish from the tidal pools, and in an adjacent area, he left the tidal pools as he found them. Prior to removing the starfish, he sampled all the organisms in each pool. After two months, he repeated this sampling. A summary of his results is illustrated in the graph below.
If this was an ecosystem-level study, what additional data might Paine need to collect?
Definitions:
Petty Cash Vouchers
Documents used to manage and record small, usually incidental, expenses paid out in cash from a designated petty cash fund.
Nontrade Receivables
Nontrade receivables are amounts owed to a company that are not related to the sale of goods or services, such as loans and advances given.
Advances to Subsidiary
Funds provided by a parent company to its subsidiary as an intra-company loan or for investment purposes.
Compensating Balance
A minimum account balance that a borrower must maintain as a condition for borrowing from a bank.
Q6: Many weed species such as dandelions are
Q14: A nucleotide is the building block of
Q18: In a simple laboratory experiment, a researcher
Q21: Bones, joints, and muscles form part of
Q39: During the production of beer, the barley
Q39: Which of the following hormones plays a
Q43: Your PC works with data that has
Q45: Data sent to a printer, modem, or
Q52: The study of dendrochronology allows scientists to
Q56: A ripened ovary is called a(n)<br>A) endosperm.<br>B)