Soil pH
Fluctuations of pH might be caused due to seasonal climate and soil physical-chemical changes, which affect value of pH. Therefore a range of pH is presented to show possible pH variations in a soil samples.
| Sample ID | Succession class | Average of experiments | |
| Potassium chloride KCl | Demi water | ||
| 1 | Forest (north) | 3.94 | 6.09 |
| 2 | Grassland – edge of northern forest | 4.53 | 5.8 |
| 3 | Bare sand | 4.77 | 6.07 |
| 4 | Heathland | 4.75 | 6.45 |
| 5 | Heathland with bare sand | 4.77 | 5.78 |
| 6 | Grassland | 4.40 | 5.85 |
| 7 | Forest (south) | 4.06 | 5.74 |
| 8 | Heathland | 4.50 | 5.97 |
| 9 | Bare sand | 5.01 | 5.75 |
Table 1: pH of soil samples
According to pH classification ranges, pH of sampled soils would fall in a range of extreme to very strong acid based on pH in KCl solution, where in demi water it falls in moderate to slight acid. Also, variations in pH in different succession stages do not differ significantly. There, more acidic pH is in both forest areas (pH= 3,94 and 4,06) and grassland (pH = 4,40). Also, relation between pH and content of soil organic matter (SOM) can be made. SOM acidify soil by producing hydrogen ions which lower the pH. Both soil samples of forest (1 and 7), heathland (8) and grassland (6) have higher content of SOM and lower pH than other analysed sites.
Cation exchange capacity
Most of the analysed samples resulted in cation exchange capacity within negative range of -22cmol+/kg to -199cmol+/kg. Only samples 3 (bare sand) and 5 (heathland/bare sand) shows positive amounts. However, based on literature study, sandy soil has low cation exchange capacity (about 0 – 5 cmol+/kg) where clay and organic matter have high CEC, ranging between 30 – 100 cmol+/kg. Measured CEC in soil samples seems to be too high for common cation exchange capacity in a sandy soil. Therefore, results of cation exchange capacity are not reliable, which means that measurements are not accurate.
Table 2: Cation exchange capacity in analysed areas
| Sample ID | Succession class | CEC cmol+/kg |
| 1 | Forest (north) | -193 |
| 2 | Grassland – edge of northern forest | -39 |
| 3 | Bare sand | 59 |
| 4 | Heathland | -22 |
| 5 | Heathland with bare sand | 13 |
| 6 | Grassland | -199 |
| 7 | Forest (south) | -150 |
| 8 | Heathland | -29 |
| 9 | Bare sand | 809 |
However, some conclusions can be based on literature search. Most of collected soil samples have a soil texture of sand and sandy/loamy sand with low CEC. It shows that base cations or nutrients like Ca2+, Mg2+, K+ tend to be leached out in sandy soils. On the other hand, CEC might be higher in upper layers of the soil with higher soil organic matter content. For example, sampled areas of grassland (2) and heathland (7) would have higher CEC because of higher soil organic matter content (see results of soil organic matter). Because of that, nutrients availability and soil stability are expected in these areas, which lead to favourable conditions to succession rates.
Nitrogen mineralisation
In order to determine net mineralisation rates over time, concentrations of nitrates, nitrites and ammonium are necessary to know. Determination of nitrogen mineralisation and nitrification in a soil was not finished because of technical failure of laboratory equipment. Therefore, only samples of ammonium nitrogen (NH4-N) concentrations have been measured.
In table 3, it can be seen that not all ammonium nitrogen concentrations are identified, because some samples were under detection limits of ions chromatography. Results show, that higher NH4-N concentrations have been detected in bare sand areas (sample 3 and 9) and heathland with open areas of bare sand (sample 5). In general, ammonium nitrogen concentrations did not differ significantly within different succession stages, but are higher in areas of bare sand.
Table 3: Ammonium nitrogen increase in nitrogen mineralisation experiment
| NH4-N concentrations, mg/l | |||||
| Sample ID | Day 0 | Day 4 | Day 8 | Day 14 | |
| 1 | Forest (north) | n/a | n/a | n/a | n/a |
| 2 | Grassland – edge of northern forest | n/a | n/a | n/a | 28.05 |
| 3 | Bare sand | n/a | 1.98 | n/a | 29.71 |
| 4 | Heathland | n/a | 2.11 | n/a | 29.56 |
| 5 | Heathland with bare sand | n/a | 2.11 | n/a | 31.77 |
| 6 | Grassland | 1.94 | 2.11 | n/a | 26.67 |
| 7 | Forest (south) | n/a | 2.03 | n/a | 28.89 |
| 8 | Heathland | n/a | n/a | n/a | n/a |
| 9 | Bare sand | n/a | 1.98 | n/a | 34.92 |
n/a – under detection limits
Interestingly, the highest NH4-N concentration (34,92mg/l) was found in bare sand (sample 9) near the main entrance of the park. These variations might be caused by the fact that higher NH4-N concentration was found near the horse pathway and close to agricultural zone, which possible influence higher nitrogen depositions to the bare sand. Ammonium is common form of deposited nitrogen and it gives a basis to nitrogen mineralisation, so the assumption can be made that net nitrogen mineralisation will be greater in areas with higher NH4-N and soil organic matter contents. Comparing organic matter content and ammonium nitrogen concentrations, it can be predicted that possible higher net nitrogen mineralisation rates would result in sites of heathland (sample 6) and grassland (sample 8).
The Dune Whisperers 