Summary: Plant Ecology 138: 127135, 1998.
© 1998 Kluwer Academic Publishers. Printed in the Netherlands.
Defoliation and woody plant (Prosopis glandulosa) seedling regeneration:
potential vs realized herbivory tolerance
Jake F. Weltzin1, Steven R. Archer & Rodney K. Heitschmidt2
Department of Rangeland Ecology and Management, Texas A & M University, College Station, TX 778432126,
USA; 1Corresponding author: Department of Biological Sciences, University of Notre Dame, Notre Dame, IN
46556, USA; 2USDA/ARS Ft. Keogh, Rt. 1, Box 2021, Miles City, MT 59301, USA
Received 27 March 1997; accepted in revised form 27 April 1998
Key words: Browsing, Clipping, Competition, Honey mesquite, Survival, Texas, Top removal
Herbivory by rodents, lagomorphs and insects may locally constrain woody plant seedling establishment and
stand development. Recruitment may therefore depend either upon plant tolerance of herbivory, or low herbivore
abundance, during seedling establishment. We tested potential herbivory tolerance by quantifying growth, biomass
allocation, and survival of defoliated Prosopis glandulosa seedlings under optimal abiotic conditions in the absence
of competition. Realized tolerance was assessed by clipping seedlings of known age grown in the field with and
without herbaceous competition.
At 18-d (= `young') or 33-d (= `old') of age, seedlings in the growth chamber were clipped just above the
first (cotyledonary) node, above the fourth node, or were retained as non-clipped controls. Potential tolerance to