EFFECT OF LIGHT AND WATER‐STRESS ON PHOTOSYNTHESIS AND BIOMASS PRODUCTION IN BOLTONIA DECURRENS (ASTERACEAE), A THREATENED SPECIES
Abstract
Boltonia decurrens (Torrey & Gray) Wood, a perennial species endemic to the Illinois River Valley, is threatened with extinction. Construction of a system of dikes along the Illinois River has altered flood patterns during the last 100 years, converting wet prairies and natural marshes to cropland. Remaining shore habitats have been modified by heavy siltation and altered flooding regimes. Boltonia decurrens is now confined to areas that are disturbed by occasional cropping, disappearing from sites after 3 to 5 years of natural succession. This study was conducted to determine the role of light and water availability upon growth and reproduction. Our data indicate that under greenhouse conditions B. decurrens requires high levels of light for optimal photosynthesis and growth, and is more sensitive to reductions in growth light level than to moderate drought‐stress. This sensitivity to light regime may help explain its disappearance from disturbed areas after several years of natural succession. If B. decurrens is overtopped by fast‐growing species, it could be shaded to the extent that growth and seed production would be severely affected, increasing the likelihood of its extinction.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 01, 1993
- Source ID
- 10.1002/j.1537-2197.1993.tb15305.x
Entities
People
- Marian Smith
- Olivia Green
- Yajun Wu
Organizations
- Southern Illinois University
- United States Army Corps of Engineers
- United States Fish and Wildlife Service