CWT-LTER Data Set Summary

Accession: 1102 CWT Research Theme: Plant Ecology
Contributors: Katherine Elliott, Jason Love
Title: Tree growth (1999-2012) for the Functional Diversity project, Coweeta Hydrologic Laboratory, Otto, North Carolina
Abstract: The importance of the herbaceous layer in regulating ecosystem processes in deciduous forests is generally unknown. We use a manipulative study in a rich, mesophytic cove forest in the southern Appalachians to test the following hypotheses: (i) the herbaceous functional group (HFG) in mesophytic coves accelerates carbon and nutrient cycling, (ii) high litter quality input and rapid nutrient turnover associated with HFG will have a positive effect on overstory tree growth, and (iii) the HFG regulates tree regeneration with negative effects on seedling establishment due to competition for resources. We established treatment plots in a mesic, cove-hardwoods forest and removed the herbaceous flora (HR, removed twice per year) or added herbaceous organic material (OMA, once per year) for comparison to a no removal (NR) reference for a total of 14 years. The OMA treatment stimulated soil N-mineralization and increased litterfall mass and N content. OMA N-mineralization rates were more than two times greater than both the NR and HR treatments; however, we did not detect significant differences in soil CO2 efflux among treatments. Higher overstory litterfall mass and N in the OMA treatment plots indicated that overstory trees were benefiting from the enhanced soil N-mineralization. Higher overstory leaf mass and N suggests an important linkage between HR and aboveground net primary production even though this did not translate into greater tree basal area increment. We found an increase in regeneration of all tree species with HFG removal, and the response was particularly evident for Acer rubrum seedlings.
Key Words: aboveground production, Coweeta LTER, diversity, functional group, herbs, mesophytic cove, net primary production, Primary Production, Disturbance, species diversity, tree growth
LTER Core Area: Primary Production
CWT Themes: Plant Ecology, General Nutrient Chemistry
Study Type: Coweeta LTER / USDA FS Long Term Monitoring
Study Period: 10-Feb-1999 to 04-Jan-2012
Site References:
CWTBASIN -- Coweeta Basin, Macon County, North Carolina, USA
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Data References: 1112

Data Table: 1102 (Main data table for data set 1102, 4321)

Access: Public (released 15-Sep-2015)

Metadata: Text (ESA FLED), Basic EML, Complete EML

Data Formats: Spreadsheet CSV Text Format, EML-described Text Format, Tab-delimited Text Report with Statistical Summary, GCE Data Toolbox Format, Standard MATLAB Variables Format

Column List:

Column Name Units Type Description (hide)
1 Plot none integer Plot number
2 Treatment none alphanumeric string Treatment type
3 Tag_Number none floating-point Tree tag number
4 Species none alphanumeric string 6 letter acronym code of tree species
5 Date mm/dd/yyyy floating-point Calendar date
6 Den_Band_Measurement mm floating-point Dendrometer band measurement
7 DBH cm floating-point Diameter measured at breast height (1.37m)
8 Status none alphanumeric string Status of tree