Root sampling will not be part of the core LIFEPLAN sampling, but will instead be a voluntary, shorter module. Soil sampling will be part of the core protocol, but the selection of sampling points will be modified in August 2020.
- Disposable gloves
- Tissue paper
- Hard 5-cm inner diameter PVC pipe
- Clear plastic bags
- Paper bags
- Airtight Zip-lock bags with QR codes
- Silica gel
Equipment you provide
- Knife (sharp and strong, at least 5 cm blade)
- Gardening spade
- Ruler to measure 5 cm depth
- Ethanol / flame
- Cooler box: styrofoam or similar
- Freezer (preferred) or refrigerator for sample storage
At each site, you should take two types of soil samples eight times a year: soil samples and samples of roots of known plants. The eight sampling events should be distributed evenly over the entire plant growing season. Thus, in the Arctic region, the sampling times will be distributed along the few months of plant growth (i.e. the snow-free season), whereas in tropical regions the sampling times will be distributed over the whole year. As illustrated in Figure 4 below, for each plant individual, you should collect two Sample Pairs, each pair consisting of a root sample and a soil sample.
Figure 4: Root and soil sampling with different types of plants. A root sample and soil sample from the same plant make a Sample Pair. For each target plant, take two Sample Pairs.
Figure 5. Root and soil sampling schedule. Each sampling event consists of 6 Sample Pairs from three different plant species, and 2 Sample Pairs from pooled samples from ten plant species, for a total of 8 Sample Pairs. One Sample Pair = 1 root sample + 1 soil sample.
Focal plant species selection
Fill in the spreadsheet by clicking here
For each location, we will select three focal plant species. The focal plant species should fulfill the following criteria:
1. The focal plants should be known to establish ECM (ectomycorrhizal) associations. Therefore, predominantly herbaceous families such as Poaceae or Asteraceae are excluded. However, if your study region does not have any plants that form ECM associations, then plants that form other kinds of fungal associations can be selected.
2. The focal plants should be ones where it is possible to sample their fine roots (under 2 mm in diameter). The feasibility can be best tested by uprooting individuals and examining their root structure. Tree species with deep roots are difficult to sample.
3. The focal plants should, if possible, be ones that are present at both the urban and the natural site (for sites included in the global design). If there are no shared species between the two sites, different species can be used.
4. The focal plants should be widespread, so that same species can be shared between as many global locations as possible.
Criterion 4 requires coordination among all the sites. To achieve this, we ask each participating site to provide suggestions of focal plant species that would fulfill criteria 1-3 for their site, and that would additionally have high potential to fulfill criterion 4 by having a wide range. You can suggest as many plant species as you like, preferably at least five. Provide your suggestions hereby finding your site name (listed in the first column), entering your name in the next column and adding scientific names of plant species in the subsequent columns.
Each sampling event: take two Sample Pairs (root and soil) of 3 focal plant species, AND two Sample Pairs of pooled root samples and pooled soil samples of 10 different plant species (8 Sample Pairs in total). See Figures 4 and 5.
To avoid contaminating and cross-contaminating the samples, wear disposable gloves and change them each time when handling soil or roots from a different point. Clean the tools with ethanol or flame between the sampling points.
Once you have dug up the plant for the root sample using a knife or spade, you should gently clean the fine roots (under 2 mm diameter) of soil particles by hand (using disposable gloves). Clip the fine roots into a tissue.
Store the replicate root samples separately by wrapping them in tissue paper and placing them in individual paper bags, which are then placed inside individual plastic zip-lock bags containing silica gel, which will draw out the moisture. If the root samples are wet, then it is recommended to change the tissue paper and silica gel within 24h.
The soil samples are taken using a 5 cm diameter pipe close to (i.e. at a distance of ca. 10 cm from) where the root sample was taken. Press the pipe into the soil to make a mark, and use a knife to cut a 5 cm deep circle using the mark as a guide. Use a tablespoon to dig out the resulting core to a depth of 5 cm into a clear plastic bag. Clear the soil of big particles such as stones, litter, wood pieces and plant roots, picking them out with gloved hands. Then take a subsample of three tablespoons of soil into a paper bag. Place the paper bag inside a zip-lock bag containing silica gel, which will draw out the moisture. Again, store the two replicate soil samples in different paper and plastic bags.
Store dried samples in a freezer and mail to LIFEPLAN as soon as possible.
In the case of small plants, you should sample a different plant individual every time. In the case of trees, a different individual is also targeted each time. Note that this implies that the focal species selected should be sufficiently abundant, as over the 6 years of the project duration 48 individuals will be sampled per site (6 years x 8 sampling times). If this proves unfeasible, then we will opt for an alternative design.
In addition to the paired root and soil samples, you should collect two pairs of pooled root samples and soil samples (Figure 5). For these, you should sample the roots of 10 plant individuals each representing a different species (randomly selected from those available within the sampling plot), pooling these into a single sample. At the same time, you should sample a soil core next to each of these 10 plant individuals, and mix these cores into a separate sample. The identity of the 10 plant species can vary freely between sampling events, and needs not to be noted. (However, you are encouraged to write them down if you hold sufficient taxonomical expertise). There is no need to keep track of which plant individual has already been sampled for the additional sampling.
In summary, for each sampling event, you should take a total of eight root samples and eight soil samples. During the eight sampling events of each year, you will thus accumulate a total of 64 root samples and 64 soil samples. Samples are shipped to the LIFEPLAN project team as soon as possible.