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Abstract Detail

Recent Topics Posters

Bucior, Erika [1], Melcher, Peter [2].

The Competitive Exclusion Principle in Action: The Impacts of Invasiveness in Costal Habitats on Culebra, PR.

Physiological and morphological characteristics were measured on an introduced and a native plant species, Scaevola taccada and Scaevola plumieri, respectively. These species compete for similar resources in coastal habitats on Puerto Rican islands.  According to the competitive exclusion principle, two species that grow in the same place and do not hybridize cannot coexist using exactly the same resources.  Previous studies have found that hybridization does not occur between these two species, making them complete competitors. The aim of this research was to determine if the S. taccada will outcompete and drive the native species to extinction.  From photosynthetic light response curves we found that the S. plumieri had significantly higher maximum photosynthetic rates of 23.5±3.7 STDEV compared to the introduced S. taccada species with 18.7±3.4 [W=132; p=0.0145]. These data did not support our hypothesis that the introduced species would have higher photosynthetic rates.  From biomass allocation and leaf area studies we found that the S. taccada produced significantly more leaf area per stem than S. plumieri and that S. taccada leaves had much less biomass and lower respiration rates measured on a per leaf area basis (p <0.001).  This resulted in significant changes in subcanopy light environments for each species, with reductions in photosynthetically active radiation of 69.2% and 92.8% for S. plumieri and S. taccada, respectively (p<0.001). Subcanopy species diversity was also much higher for S. plumieri compared to S. taccada. These findings support our hypothesis that S. taccada will eventually dominate the coastal landscape where these species co-exist.

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1 - Ithaca College, Dept. of Environmental Studies & Sciences, 953 Danby Rd, Ithaca, NY, 14850, USA
2 - Ithaca College, Center For Natural Sciences, Ithaca, NY, 14850, USA

ecophysiological traits

Presentation Type: Recent Topics Poster
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PRT002
Abstract ID:1778
Candidate for Awards:None

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