Study Locations - Reclamation Sites
2-yr Reclamation Site
- Planted in 2019 with a mix of P. tremuloides, P. glauca, & P. banksiana - Soil (35cm peat over 21cm clay) was placed in winter 2018-2019 |
18-yr Reclamation Site
- Planted in 2006 with a mix of P. tremuloides & P. glauca - Soil (15cm peat over 20cm clay) was placed in 2004 |
30-yr Reclamation Site
- Planted in 1992 with a mix of P. tremuloides & P. glauca - Soil (100cm peat mineral mix) was placed in winter 1990-1991 |
Study Locations - Reference Sites
Native Shrub Species
Study Design
PLANTING & MEASURING:
Seedlings were picked up from the Smoky Lake Forest Nursery in May 2019 and placed in a 4°C refrigerator at the University of Alberta North Campus until time of planting. Edmonton sites were planted first, starting on May 24th and ending on May 29th, 2019. Reclamation sites were planted between June 12th and June 14th, 2019. After planting, initial mensuration of seedlings occurred and various morphological measures were recorded. These measures differed across species:
** Growth data were not analyzed for the scope of this REN R 690 project ** SITE CHARACTERIZATION: Sites were characterized by the following environmental variables:
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Statistical Methods
Statistics used in this project were entirely descriptive (i.e., no significance values). First, direct and indirect gradient analyses were carried out via non-metric multidimensional scaling (NMDS) plots in the vegan package of R software (v 3.2.2; R Foundation for Statistical Computing, Vienna, Austria). Response variables were scaled/normalized using the Euclidean distance method in the ecodist package of R software. Secondly, regression trees were run using classification and regression tree analysis (CART) in the mvpart package of R software to detect potential associations between the predictor (environmental) variables and response (shrub seedling survival) variables.