Adaptation to exploit nitrate in surface soils predisposes yellow-cedar to climate-induced decline while enhancing the survival of western redcedar: a new hypothesis
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Forest Ecology and Management. 258: 2261-2268.
Yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) and western redcedar (Thuja plicata Donn), two valuable tree species of Pacific Northwest forests, are competitive in low productivity forests on wet, nearly saturated soils with low nitrogen (N) availability and turnover. We propose a mechanism where cedar trees survive in marginal conditions through exploiting a coupled Ca-NO3-nutrient cycle where trees assimilate N as nitrate (NO3-), butmust accumulate a counter-ion to NO3- such as calcium (Ca+2) to control their internal cell pH and provide electrochemical balance. The availability of NO3- in cedar forests is favored by increased microbial activity and shifts in microbial community composition that is conducive to N mineralization and nitrification at higher pH. Cedars influence the soils under their canopy by enriching the forest floor with calciumcompounds leading to increases in pH.
D'Amore, David V.; Hennon, Paul E.; Schaberg, Paul G.; Hawley, Gary J. 2009. Adaptation to exploit nitrate in surface soils predisposes yellow-cedar to climate-induced decline while enhancing the survival of western redcedar: a new hypothesis. Forest Ecology and Management. 258: 2261-2268.