<Citation>   <Acknowledgement>   <Disclaimer>   Griffiths, R. 2002. Influence of tree-fall gaps on soil characteristics in gaps of varying sizes in the Andrews Experimental Forest, 1995. Long-Term Ecological Research. Forest Science Data Bank, Corvallis, OR. [Database]. Available: http://andlter.forestry.oregonstate.edu/data/abstract.aspx?dbcode=SP017. Accessed 2024-10-03. Data were provided by the HJ Andrews Experimental Forest research program, funded by the National Science Foundation's Long-Term Ecological Research Program (DEB 2025755), US Forest Service Pacific Northwest Research Station, and Oregon State University. While substantial efforts are made to ensure the accuracy of data and documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is". The Andrews LTER shall not be liable for damages resulting from any use or misinterpretation of data sets.
This is the first of three tree-fall gap studies conducted at the H.J. Andrews Experimental Forest addressing the effects of tree-fall gaps on forest soil characteristics. The second (Gap2) compared the effects of gaps on soil properties along both N-S and E-W transects to better differentiate between microclimate and vegetation effects within gaps. The final study (Gap3) expanded the number of variables studied and sampling intensity. By using the same grid system as Dr. Andy Gray in his vegetation survey work, the Gap3 study provided the most definitive connection between above-ground vegetation and associated below-ground processes.
Soil properties in 10, 20, 30, and 50 meter tree-fall gaps were compared with soils in the surrounding old-growth Douglas-fir forest by sampling at 1 meter intervals along transects running north and south through the gaps. These transects extended one radius into the surrounding forest. This study was designed to determine if carbon cycling within these gaps were different from those in the soils of surrounding undisturbed forests. If there were differences, she wanted to determine what sized gap was required to show an effect. These transects were divided into four zones. Two zones were north of the E-W centerline; one in and one out of the gap. The other two zones were south of the E-W centerline; one in and one out of the gap.