Which of the following would be an example of an organism creating a positive feedback interaction with its environment? tamarisk shrubs are highly salt-tolerant; they take up salty water, but have special glands that secrete excess salt onto their waxy leaf surfaces, thus storing it out of the way where it can’t harm their cells. when the foliage falls, the salts wash into the soil, increasing the soil salinity. over time, the salinity increases to a level that is toxic to almost any plant other than the tamarisks, which allows their offspring to grow where other plants have died. unlike most organisms, nitrogen-fixing bacteria can grow well in soils with very low levels of available nitrogen, because they can convert n2 into a biologically-available form, which they can use to support their own growth. as numbers of n-fixing bacteria increase, more nitrogen becomes available in the soil, in part because some usable nitrogen “leaks” into the environment, and in part because the cells eventually die, releasing all of their usable nitrogen into the soil. as the levels of usable nitrogen increase, other organisms can grow near the n-fixing bacteria, competing with them for other resources, like carbon and water.