Summary: Plant Ecology 160: 193205, 2002.
© 2002 Kluwer Academic Publishers. Printed in the Netherlands.
Leaf demography and growth responses to altered resource availability in
woody plants of contrasting leaf habit in a subtropical savanna
Jim A. Nelson1,, Paul W. Barnes1 & Steve Archer2
1Department of Biology, Southwest Texas State University, San Marcos, Texas 78666-4616, USA; 2Department of
Rangeland Ecology and Management, Texas A&M University, College Station, Texas 77843-2126, USA; Current
address: USDA/ARS Crops Research Laboratory, 1701 Centre Ave, Fort Collins, CO 80526, USA (E-mail:
Received 29 July 2000; accepted in revised form 30 January 2001
Key words: Functional groups, Leaf longevity, Leaf habit, Resource partitioning, Soil moisture
Leaf demography and growth of six common, co-occurring woody plant species that varied in stature (tree vs.
shrub) and leaf texture (sclerophyllous, coriaceous, malacophyllous) were examined in a subtropical savanna
parkland in southern Texas, USA. We tested the hypotheses that, (a) leaves of plants with evergreen canopies
would have longer life spans than those of deciduous species; (b) supplementation of soil moisture would decrease
leaf life span in both evergreen and deciduous species; (c) species responses to increased soil moisture availability
would be inversely related to leaf longevity; and (d) deciduous growth forms would exhibit a greater growth
response to increased soil moisture availability than their evergreen counterparts.