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Study Number: |
1109 |
|---|---|
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Project Title: |
South-facing slopes and the fundamental niche of shade tolerant evergreen herbs. |
|
Investigator(s): |
Robert J. Warren, II
E-Mail | Tel. (706)
542-3407 Ron Pulliam E-Mail | Tel. (706) 542-6010 | Fax (706) 583-0646 |
| Affiliated Institution(s): | University of Georgia |
| Address: |
Institute of Ecology University of Georgia Athens, Georgia 30605 USA |
| Study Category: | Terrestrial |
| Project Type: | Type 1 |
| Study Period: |
03/2006 - 03/2008 |
| Notes: |
|
Funding Source(s): |
National Science Foundation, Grants DEB-9632854 and DEB-0218001 to Coweeta LTER. |
| Abstract: | Doctoral research: Plant ecologists have long recognized environmental and vegetational differences between north- and south-facing slopes, yet the mechanisms connecting the contrasting physical environments and associated plant communities are largely unidentified. Current niche theory suggests that the absence or rarity of three evergreen herbaceous species on south-facing slopes does not, in itself, delineate the plants’ suitable habitat. As such, this research project will test whether the distribution pattern does indicate fundamental niche limits. The objectives are to determine: (1) If environmental factors limit evergreen herb species from south-facing slopes, (2) if they perform best at maximum or intermediate (optimal) resource levels (3) if they have the same maximal or optimal responses to environmental gradients and (4) if spatio-temporal trade-offs exist in their functional trait response to the environmental gradients on north- and south-facing slopes. These objectives will be tested by transplanting the evergreen herbs to north- and south-facing slopes in order to assess plant performance as a function of the contrasting slope conditions. Specifically, carbon gain (photosynthetic rate), photoinhibition (light damage) and functional traits (i.e. leaf size) of the plants will be measured to gauge the impact of seasonal light, soil moisture, temperature and soil edaphic factors. The assumption that current and future species distributions will match suitable habitat distribution often drives predicted plant response to environmental change. By testing that assumption, this project will advance the ability to understand the distribution of organisms, a longstanding goal in ecological research. In addition, this project will contribute to the body of work on niche theory, which has been neglected in recent decades. The broader impact of these advances is the ability to accurately predict and monitor potential plant distribution shifts in response to global climate change. |
| Location(s), Described: |
South site 1: Watershed 1, just up first
north turn-off road from Shope Fork Rd. South site 2: Watershed 10?,
about 100 meters east of Camprock Branch crossing with first north
turn-off road from Shope Fork Rd. South site 3: Watershed 36, just north
of turn-off road at Pinnacle creek from Shope Fork Rd. North site 1:
Watershed 12, just north of turn-off road near Ball Creek fork from Ball
Creek Road. North site 2: Watershed 12, north of Ball Creek Road, due
east of North Site 1. North site 3: Watershed 6, off first turn-off road
from Ball Creek Road, where turn-off road takes first sharp north turn. South site 1: 35 03.780N; 83 26.010W South site 2: 35 03.992N; 83 26.877W South site 3: 35 03.510N; 83 27.912W North site 1: 35 03.546N; 83 27.912W North site 2: 35 02.342N; 83 27.912W North site 3: 35 03.327N; 83 25.694W |
| Location(s), Download GPS: | ArcView Shape Files (shp.): Decimal Degrees | UTM, NAD83, Zone 17 |
| Location(s), Online Map(s): | Online Map |
| Methods/Experimental Design: | I will establish transplant gardens at CWT and WHF on north and south slopes to investigate plant performance and functional trait response in the different environments. In addition, I will manipulate light levels with neutral shade cloth (blocks 25% of incoming light) and soil moisture with supplemental water. At each location (CWT and WHF), 36 1x1 m quadrats will be split between each slope aspect type (north and south). The quadrats will be further subdivided equally among three sites sharing the same aspect. The quadrats will be arranged in pairs (blocks) perpendicular to the slope aspect and receive one of four treatments: ambient light, 25% shaded light, ambient moisture and enhanced moisture. Thus, 9 replicates of each species (H. nobilis, H. arifolia and G. pubescens) will be used for each treatment (slope aspect, light and moisture). Two plants of each study species will be randomly transplanted into each quadrat (n=6 plants/quadrat; 288 plants/location) during the winter of 2005. Additionally, seedlings from each species will be transplanted into the quadrats to undergo the same treatments. |
| Sampling Frequency: | Four times per year. |
| Data Columns: |
[Variable]
[Description/Method/Equipment] Quantum yield/efficiency – LI-6400 portable photosynthesis system Maximum rate of carbon fixation – LI-6400 portable photosynthesis system Dark respiration – LI-6400 portable photosynthesis system Chlorophyll fluorescence - modulated fluorometer Leaf size - one-sided projected surface area Leaf dry matter - oven-dry mass Specific leaf area (SLA)- one-sided area divided by dry mass)— Soil moisture - handheld TDR unit PAR - Decagon wand UV-B - erythemal-weighted (280-400 nm) UV detector |
| Publications: |
None. |
| Data Restrictions: | Users must adhere to the Coweeta LTER Data Policy. |
| Metadata: |
EML Format (XML Schema) |
Information
about EML 1109.TXT |
| Data Downloads: | This project is new and still in the data collection phase. |