Spatial and temporal variability of the interception in the natural wetland valley, the lower Biebrza basin case study

Abstract

Spatial and temporal variability of the interception in the natural wetland valley, the lower Biebrza basin case study. The paper presents the research carried out in the lower basin of Biebrza River valley in order to identify interception for natural wetland plant communities. Maximum interception, i.e. the largest amount of water, expressed in millimeters, which can be captured and retained by plant canopy from rainfall is one of the key parameters of the water cycle modeling. Maximum interception was determined based on the difference of the masses of wet and dry fresh plant samples. Collection of plant material samples took place during the five measurement sessions, which began immediately after the flood recedes, and then lasted until the end of the growing season. Interception spatial variability was analyzed on the basis of the results of maximum interception measured for selected plant aggregations in the different sampling points. The obtained values were extrapolated to the area of the lower basin of Biebrza River using vegetation map of the Biebrza National Park. By conducting a test sessions in the five coming months, the maps of the spatial variability also show changes over time. Methodology used in the described tests allowed for obtaining of satisfactory results. They present, in a correct way, variation occurring between the plant aggregations due to their morphology. In most cases the results are consistent with data from the literature. As results of the analysis of spatial variability of the maximum interception, the highest values were found for the plant communities located in the immediate vicinity of the river channel. With the increase of the distance from river towards the valley edges the maximum interception values decrease. These changes can be seen in the form of strips parallel to the river channel, which corresponds to the plant zones. Obtained map of spatial variability of the maximum interception, which is the results of extrapolation of the values assigned to plant communities, has a high correlation with the map resulting from the analysis of satellite images

Modelling Wetland Growing Season Rainfall Interception Losses Based on Maximum Canopy Storage Measurements

“…In this research, the smallest value of maximum canopy storage is 0.19 mm, but the upper limit of the result is higher than 1 mm, reaching 1.61 mm (Table 1). Another research conducted in the Lower Biebrza Valley (to the south of the study site) shows that, for selected species, maximum canopy storage can range from 0.87 mm to 7.37 mm [45]. When compared with our work, results presented in [42] seems to be overestimated.…”

“…We also would like to note that the sampling sizes and submerging techniques for the other study are different. In this study, each plant sample of 25 cm × 25 cm grid has been split for individuals' plants and measurement taken one by one, but, in [45], the whole plant sample in the 10 cm × 10 cm square has been submerged, which leads to a better generalisation of results in this study.…”

“…Other values were linearly interpolated assuming that I max is 0 at the beginning and end of the growing season. Previous research on wetland meadow canopy storage in this area [35,36,45,47] also focused only on the growing season. This is due to the negligible height of sedge communities before and after the growing season in this area.…”

“…I max is calculated as the difference between the freshly collected and the weight of a soaked plant. There are two methods of soaking plants with water: spraying [21,31,32,44] and submerging [1,19,45]. In this study, plants were submerged because it is less ideal with spraying where the droplet size will cause variations [46].…”

Variation in Leaf Surface Hydrophobicity of Wetland Plants: the Role of Plant Traits in Water Retention

“…The relationships between CA and SFE and plant traits were found for both adaxial and abaxial surfaces of the leaves but SFE on the abaxial surface was not related to any of the traits measured. Ignar et al (2013) demonstrated that interception in wetlands had been underestimated and can account for a substantial share of the rainfall. Knowing plant's individual strategies allows us to forecast how much water will be retained on the plant surface.…”