Abstract Detail

Don Kaplan - his legacy: Influencing teaching and research

Richards, Jennifer [1], Ivey, Christopher [2].

Applied Morphology: The relevance of plant form to ecosystem ecology..

Understanding ecosystem processes is a primary challenge for humans in the 21st century. Underlying ecosystem processes are the primary producers. In terrestrial and wetland landscapes, plants are major components of the primary producer biota. Plants respond developmentally to biotic and abiotic influences, altering morphology and physiology. Plant morphology thus provides an indicator of ecosystem status and reflects both the plant’s history in an environment and its strategy for maximizing biomass production and reproduction in that environment. Understanding how morphology relates to environmental parameters can thus provide information on environmental conditions, whereas knowing how plants respond to changes in limiting factors, such as nutrients or water, allows us to predict responses to ecosystem alterations, such as restoration efforts. We have studied how soil total phosphorus and ash-free dry weight explained variation in leaf morphology of two wetland macrophytes, Cladium jamaicense and Sagittaria lancifolia, collected from randomly chosen locations throughout the southern Florida Everglades ecosystem. We modeled these relationships using reduced-rank regression, which accounted for the correlation structure in morphology. The responses of the two species differed, and these responses were consistent through southern Florida’s wet and dry seasons. Variation in the morphology of C. jamaicense plants was explained primarily by soil ash-free dry weight, which can distinguish peat from marl soils in the Everglades and is related to hydroperiod. Variation in S. lancifolia morphology was explained primarily by soil phosphorus; in particular, leaf lamina width increased disproportionately to other morphological characters with increasing phosphorus. Additional greenhouse experiments that varied phosphorus levels in growth solutions confirmed that S. lancifolia leaf morphology, and especially blade width, increases with phosphorus when other nutrients are not limiting. Because phosphorus is the limiting nutrient in the Everglades ecosystem, S. lancifolia blade width may provide a field indicator of nutrient status.

Related Links:
Richards Homepage

1 - Florida International University, Dept. of Biological Sciences, 11200 SW 8th St., Miami, Florida, 33199, USA
2 - Illinois Natural History Survey, Center for Biodiversity, 607 E. Peabody Dr., Champaign, Illinois, 61820, USA

Keywords:
Sagittaria
sawgrass
soil phosphorus
soil ash-free dry weight
bioindicator
Everglades
Cladium.

Presentation Type: Symposium
Session: 33-6
Location: Ballroom 2 (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 3:55 PM
Abstract ID:339