Research Grants/Fellowships/SBIR

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) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Natural and Life Sciences , Biology/Life Sciences

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.