Acacia Species: Establishment and Maintenance of Thorn Scrub

Project Number:

01R-05

Project Duration:

24 months

Dates:

May 1, 2001 to April 30, 2003

Institution of Principle Investigator while on this project:

University of Illinois

Professor, Department of Plant Biology, University of Illinois, 505 S. Goodwin Ave., Urbana IL 61801

TEL: +1-217-333-7577, FAX: +1-217-244-7246, Email: d-seigler@uiuc.edu

Research Associate, Department of Plant Biology, University of Illinois, 505 S. Goodwin Ave., Urbana IL 61801, USA

TEL: +1-217-333-7577, FAX: +1-217-244-7246

Department of Plant Sciences, Tel Aviv University, Tel Aviv, ISRAEL

TEL: +972-3-640-9190, FAX: +972-3-640-9380, Email: jfried@post.tau.ac.il

Major findings of this project:

There are few seeds in the seed bank of Acaciaspecies in South Texas. More than 80 species of other plants were grown from soil seed bank samples.
Recruitment of the 5 major Acacia species studied is quite low and apparently episodic.
In contrast to literature reports, nitrogen levels beneath Acacia and Prosopis species were extremely low and not different from those of surrounding areas without these species.
Acacia species were especially effective nurse plant species.
Predation of Acacia seeds by bruchid beetles is quite high (in some instances as high as 90%). Based on anecdotal evidence, woodrats may also be important consumers of Acacia seeds.
Comparison of control and treated areas indicated that brush control procedures result in lower biodiversity and a change in species importance values in 4 distinct community types.