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Title: Photosynthetic strategies of two Mojave Desert shrubs

Journal Article · · Great Basin Nat.; (United States)
OSTI ID:6606559

Photosynthetic production of two Mojave Desert shrubs was measured under natural growing conditions. Measurements of photosynthesis, transpiration, resistances to water vapor flux, soil moisture potential, and tissue water potential were made. Atriplex canescens (Pursh) Nutt., a member of the C/sub 4/ biochemical carbon dioxide fixation group was highly competitive in growth rate and production during conditions of adequate soil moisture. As soil moisture conditions declined to minus 40 bars, the net photosynthetic rate of Atriplex decreased to zero. However, the C/sub 3/ shrub species Larrea tridentata (Sesse and Moc. ex DC.) Cov. was able to maintain positive net photosynthetic production during conditions of high temperature and extreme low soil moisture through the major part of the season. The comparative advantages of the C/sub 4/ versus the C/sub 3/ pathway of carbon fixation was lost between these two species as the soil moisture potential declined to minus 40 bars. Desert plants have diffferent strategies for survival, one of the strategies being the C/sub 4/ biochemical carbon fixation pathway. However, many of the plants are members of the C/sub 3/ group. In this instance, the C/sub 4/ fixation pathway does not confer an added advantage to the productivity of the species in the Mojave Desert. Species distribution based on comparative photosynthetic production is discussed

Research Organization:
Univ. of California, Los Angeles
OSTI ID:
6606559
Journal Information:
Great Basin Nat.; (United States), Vol. 4
Country of Publication:
United States
Language:
English