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Title: Environmental productivity indices for a Chihuahuan desert cam plant, Agave lechuguilla

Abstract

Productivity of Agave lechuguilla, a commercially harvested plant that occurs over vast areas of the Chihuahuan Desert, was measured using conventional dry mass changes in the field and was predicted based on physiological responses to environmental variables in the laboratory. An environmental productivity index (EPI) was constructed as the product of indices for water status, leaf temperature, and photosynthetically active radiation (PAR). Each of these component indices was assigned a maximum value of unity when that variable was not limiting net CO/sub 2/ uptake over a 24-h period. Soil water potential, daily air and leaf temperatures, and PAR in the planes of the leaves at the field site in Coahuila, Mexico, could thus be quantitatively described in terms of their effect on net CO/sub 2/ uptake. Seasonal changes in PAR proportionally affected both the modest daytime net CO/sub 2/ uptake and the predominant nighttime net CO/sub 2/ uptake for this crassulacean acid metabolism plant, while seasonal variations in temperature had relatively small effects on net CO/sub 2/ uptake over a 24-h period. EPI was highly correlated with the number of new leaves unfolding each month in the field (r/sup 2/ = 0.83); counting unfolding leaves is a nondestructive method ofmore » estimating productivity. For the 1-yr study period EPI averaged 0.28, which led to a predicted annual dry mass gain per unit leaf area of 0.68 kg/m/sup 2/. Field measurements indicated that the actual dry mass gain was about half this value, the difference representing photosynthate needed for constructing and maintaining folded leaves, stem, and roots. The productivity of A. lechuguilla per unit ground area explored by its roots was 0.38 kg x m/sup -2/ x yr/sup -1/, which, although much less than for agricultural crops, is still much greater than the average productivity for desert ecosystems.« less

Authors:
;
Publication Date:
Research Org.:
Univ. of California, Los Angeles
OSTI Identifier:
5811525
Resource Type:
Journal Article
Journal Name:
Ecology; (United States)
Additional Journal Information:
Journal Volume: 67:1
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 09 BIOMASS FUELS; PLANT GROWTH; MEASURING METHODS; PRODUCTIVITY; BIOMASS; CARBON DIOXIDE; CORRELATIONS; DESERTS; METABOLISM; MEXICO; PLANTS; RENEWABLE RESOURCES; TEMPERATURE EFFECTS; TUMBLEWEEDS; UPTAKE; ARID LANDS; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; DEVELOPING COUNTRIES; ENERGY SOURCES; GROWTH; LATIN AMERICA; NORTH AMERICA; OXIDES; OXYGEN COMPOUNDS; RENEWABLE ENERGY SOURCES; RESOURCES; 510100* - Environment, Terrestrial- Basic Studies- (-1989); 140504 - Solar Energy Conversion- Biomass Production & Conversion- (-1989)

Citation Formats

Nobel, P S, and Quero, E. Environmental productivity indices for a Chihuahuan desert cam plant, Agave lechuguilla. United States: N. p., 1986. Web. doi:10.2307/1938497.
Nobel, P S, & Quero, E. Environmental productivity indices for a Chihuahuan desert cam plant, Agave lechuguilla. United States. https://doi.org/10.2307/1938497
Nobel, P S, and Quero, E. 1986. "Environmental productivity indices for a Chihuahuan desert cam plant, Agave lechuguilla". United States. https://doi.org/10.2307/1938497.
@article{osti_5811525,
title = {Environmental productivity indices for a Chihuahuan desert cam plant, Agave lechuguilla},
author = {Nobel, P S and Quero, E},
abstractNote = {Productivity of Agave lechuguilla, a commercially harvested plant that occurs over vast areas of the Chihuahuan Desert, was measured using conventional dry mass changes in the field and was predicted based on physiological responses to environmental variables in the laboratory. An environmental productivity index (EPI) was constructed as the product of indices for water status, leaf temperature, and photosynthetically active radiation (PAR). Each of these component indices was assigned a maximum value of unity when that variable was not limiting net CO/sub 2/ uptake over a 24-h period. Soil water potential, daily air and leaf temperatures, and PAR in the planes of the leaves at the field site in Coahuila, Mexico, could thus be quantitatively described in terms of their effect on net CO/sub 2/ uptake. Seasonal changes in PAR proportionally affected both the modest daytime net CO/sub 2/ uptake and the predominant nighttime net CO/sub 2/ uptake for this crassulacean acid metabolism plant, while seasonal variations in temperature had relatively small effects on net CO/sub 2/ uptake over a 24-h period. EPI was highly correlated with the number of new leaves unfolding each month in the field (r/sup 2/ = 0.83); counting unfolding leaves is a nondestructive method of estimating productivity. For the 1-yr study period EPI averaged 0.28, which led to a predicted annual dry mass gain per unit leaf area of 0.68 kg/m/sup 2/. Field measurements indicated that the actual dry mass gain was about half this value, the difference representing photosynthate needed for constructing and maintaining folded leaves, stem, and roots. The productivity of A. lechuguilla per unit ground area explored by its roots was 0.38 kg x m/sup -2/ x yr/sup -1/, which, although much less than for agricultural crops, is still much greater than the average productivity for desert ecosystems.},
doi = {10.2307/1938497},
url = {https://www.osti.gov/biblio/5811525}, journal = {Ecology; (United States)},
number = ,
volume = 67:1,
place = {United States},
year = {Sat Feb 01 00:00:00 EST 1986},
month = {Sat Feb 01 00:00:00 EST 1986}
}