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Study Number: |
1032 |
|---|---|
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Project Title: |
Gap microclimate measurements. |
|
Investigator(s): |
James M. Vose E-Mail
|
Tel.
828.524.2128 x 114
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Biographical Sketch Barry Clinton E-Mail | Tel. 828.524.2128 x124 | Biographical Sketch |
| Affiliated Institution(s): | USDA Forest Service |
| Address: |
Coweeta Hydrologic Laboratory
3160 Coweeta Lab Road Otto, North Carolina 28763 USA |
| Study Type: | Terrestrial |
| Project Type: | Coweeta Core Research |
| Study Period: | 05/1993 - 05/1997 |
| Status/Notes: | |
| Funding Sources: |
National Science Foundation, DEB-9632854 (Text Version) and DEB-0218001 (Text Version) to Coweeta LTER. |
| Abstract: |
LTER Gap Project Overview Fact: Tree mortality at small spatial scales represents background levels of forest disturbance in the southern Appalachians, and is the dominant and most frequent initiator of change in terrestrial ecosystems. Hypothesis: Large-scale and rare episodic events (i.e., hurricanes, ice, etc.) may do more to influence tree replacement and stand composition in the long-run than do small scale tree mortality events. Overall Question: What is the ecological significance of small scale mortality events with respect to biotic and abiotic responses. Approach: Experimentally create typical (<300 m2) canopy gaps (girdling and herbicides) at two elevations in Rhododendron and non-Rhododendron areas. Measurements: -automated micro-environmental measurements (air and soil temperature), photosynthetically active radiation, %WC. -hemispherical photography -dendrometer bands and repeated measurements -population dynamics and seedling physiology -in situ closed core N mineralization and nitrification -small and large mammal seed and plant herbivory using exclosures Specific Questions: 1) How are microclimate and nutrient (N) cycling affected by small scale canopy removal? 2) What are the physiological and productivity responses of advanced regeneration? 3) What is the productivity response of non-gap-maker trees (dominants, co-dominant, and saplings)? 4) What strategy for recovery is most likely (seedling recruitment, sapling ingrowth, canopy closure)? 5) How do all of the above relate to/regulate each other? 6) What is the effect of elevation on response? 7) How do responses differ in Rhododendron versus non-Rhododendron areas?  Resources
for students about terms used in this study:Succession in canopy gaps - Source: Coweeta LTER Environmental heterogeneity-tree gaps research - Source: Coweeta LTER Dendrometer Tree Bands, p. 19-21 - Source: 2001 Coweeta Field Technician Procedure Manual |
| Location(s), Described: | Watershed 18 and Watershed 27. |
| Location(s), Download GPS: | ArcView Shape Files (shp.): UTM, NAD83, Zone 17 | Lat/Lon |
| Location(s), Online Maps: |
 Online Map |
| Methods/Experimental Design: |
Soil and Air Temperatures: Thermocouples were installed at 1m above the forest floor (air temperature) and 10 cm below the forest floor surface (soil temperature) and were co-located at 11 locations along permanent transects in all non-Rhododendron gaps and 1 Rhododendron gap at each elevation. Only 1 Rhododendron gap was instrumented at each elevation because of the presumed lower variability in temperature beneath Rhododendron sub-canopies compared to areas without Rhododendron. The air temperature thermocouples were placed in a PVC shield to prevent artificial heating from direct solar radiation. Copper-Constantine wire (Type T) was used. Data were recorded automatically though a multiplexed system controlled by a CR10 data logger and down loaded periodically as needed. Data were scanned for obvious problems such as deteriorated thermocouples and repairs were made in the field as needed. The reason for monitoring soil and air temperature was to detect changes in understory microclimatic conditions due to the creation of the canopy gap.
Air temperature measured with Campbell multiplexed automated data
loggers equipped with thermocouple sensors. Thermocouples placed 1m
above the forest floor and distributed at 2m intervals across the gap.
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| Sampling Frequency: | Every two hours |
| Data Columns: |
Monthly: ID - Identifier number SITE - Coded value YEAR - Year MONTH - Month L5 - Temperature at location 18m east of center L4 - Temperature at location 8m east of center L3 - Temperature at location 6m east of center L2 - Temperature at location 4m east of center L1 - Temperature at location 2m east of center L0 - Temperature at location center of gap L_1 - Temperature at location 2m west of center L_2 - Temperature at location 4m west of center L_3 - Temperature at location 6m west of center L_4 - Temperature at location 8m west of center L_5 - Temperature at location 18m west of center Daily: ID - Identifier number SITE - Coded value PLOT - Plot number YEAR - Year JDAY - Julian day MONTH - Month L5 - Temperature at location 18m east of center L4 - Temperature at location 8m east of center L3 - Temperature at location 6m east of center L2 - Temperature at location 4m east of center L1 - Temperature at location 2m east of center L0 - Temperature at location center of gap L_1 - Temperature at location 2m west of center L_2 - Temperature at location 4m west of center L_3 - Temperature at location 6m west of center L_4 - Temperature at location 8m west of center L_5 - Temperature at location 18m west of center Hourly: ID - Identifier number SITE - Coded value PLOT - Plot number YEAR - Year JDAY - Julian day HOUR - Hour L5 - Temperature at location 18m east of center L4 - Temperature at location 8m east of center L3 - Temperature at location 6m east of center L2 - Temperature at location 4m east of center L1 - Temperature at location 2m east of center L0 - Temperature at location center of gap L_1 - Temperature at location 2m west of center L_2 - Temperature at location 4m west of center L_3 - Temperature at location 6m west of center L_4 - Temperature at location 8m west of center L_5 - Temperature at location 18m west of center Site Codes: hna - High Elevation Non-rhododendron Air-Temp; Celsius hns - High Elevation Non-rhododendron Soil-Temp; Celsius hra - High Elevation Rhododendron Air-Temp; Celsius hrs - High Elevation Rhododendron Soil-Temp; Celsius lna - Low Elevation Non-rhododendron Air-Temp; Celsius lns - Low Elevation Non-rhododendron Soil-Temp; Celsius lra - Low Elevation Rhododendron Air-Temp; Celsius lrs - Low Elevation Rhododendron Soil-Temp; Celsius Missing Data Codes: . (Period) |
| Publications: |
Representative
publications and research data from investigator(s) of this study: |
| Data Restrictions: | Users must adhere to the Coweeta LTER Data Policy. |
| Metadata: | EML Format (XML Schema) | Information about EML |
| Data Downloads: |
Monthly Gap Microclimate Measurements
1993: Microsoft® Excel (.xls) | Text Comma Delimited (.csv) | DBase (.dbf) 1994: Microsoft® Excel (.xls) | Text Comma Delimited (.csv) | DBase (.dbf) 1995: Microsoft® Excel (.xls) | Text Comma Delimited (.csv) | DBase (.dbf)
1996: Microsoft®
Excel (.xls) |
Text Comma
Delimited (.csv) |
DBase (.dbf)
Daily Gap Microclimate Measurements
1995: Microsoft® Excel (.xls) | Text Comma Delimited (.csv) | DBase (.dbf)
1996:
Microsoft®
Excel (.xls) |
Text Comma
Delimited (.csv) |
DBase (.dbf)
Hourly Gap Microclimate Measurements |