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Extramural Research

Grantee Research Project Results

NCER Grantee Research Project Results

The Relationship Between Carbon Gain, Seasonality, and Nutrient Use Among Trees of Different Successional Status in the Subtropical Upland Hardwood Forests of the Northern Florida Keys

EPA Grant Number: U916248
Title: The Relationship Between Carbon Gain, Seasonality, and Nutrient Use Among Trees of Different Successional Status in the Subtropical Upland Hardwood Forests of the Northern Florida Keys
Investigators: Redwine, Jed R.
Institution: Florida International University
EPA Project Officer: Jones, Brandon
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $93,378
RFA: Minority Academic Institutions (MAI) Fellowships for Graduate Environmental Study (2003)
Research Category: Academic Fellowships , Fellowship - Natural and Life Sciences , Biology/Life Sciences

Description:

Objective:

The objective of this research project is to detect shifts in phenological and physiological strategy using a modular sampling approach to partition the significant features of tree species that control their light and nutrient use features.

Approach:

The seasonally dry subtropical forests of the northern Florida Keys contain more than 120 species of subtropical trees, many near the northernmost extent of their range. These forests undergo a century-long primary successional process where drought-deciduous trees colonize cleared patches, and are subsequently replaced by drought-tolerant evergreen species. This shift in phenological strategy among these cosmopolitan subtropical species may be a consequence of enhanced competitive abilities of evergreen species that is particularly associated with their use of scarce light and macronutrients nitrogen and phosphorous. I will repeatedly visit 10 individuals of 10 species with contrasting successional roles every 28 days for 2 continuous years, scoring quantity of leaves and fruit and quality of leaves present. I will follow large numbers of individual leaves on branches of 4-6 individuals of 9 of the 10 species. I also plan to characterize species- and microsite-specific gas-exchange and chlorophyll content in these species. Ultimately, this approach should allow me to order species based on their integrated physiological indices such as nutrient use efficiency, and should provide a robust explanation of the important basic elements of tree biology that control ecosystem function in the broader tropical seasonally dry forest ecotype.

Supplemental Keywords:

fellowship, Florida Keys, Florida, FL, subtropical forests, nutrient use, chlorophyll content, nutrient use efficiency, NUE, successional status.

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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