Figure 1.
Location of the study area in Europe (
A), Tuchola Forest (red line) in Kujawsko-Pomorskie voivodeship (hypsometrical map), Poland (
B), and on digital elevation model LIDAR (
C). Source: [
57].
Figure 1.
Location of the study area in Europe (
A), Tuchola Forest (red line) in Kujawsko-Pomorskie voivodeship (hypsometrical map), Poland (
B), and on digital elevation model LIDAR (
C). Source: [
57].
Figure 2.
Sketch of the surface distribution of the analyzed beaver ponds with the division into active and inactive in the Gajdówka valley in 2011. (
A)—range of the valley, (
B)—flat bottom, (
C)—active ponds, (
D)—inactive ponds, (
E)—river channel, (
F)—pond numbers, (
G)—mill pond. 1–17 are the number of ponds. Source: [
56].
Figure 2.
Sketch of the surface distribution of the analyzed beaver ponds with the division into active and inactive in the Gajdówka valley in 2011. (
A)—range of the valley, (
B)—flat bottom, (
C)—active ponds, (
D)—inactive ponds, (
E)—river channel, (
F)—pond numbers, (
G)—mill pond. 1–17 are the number of ponds. Source: [
56].
Figure 3.
Example of alluvial fans and their distribution in beaver pond 3 and a sketch with the distribution of forms in a beaver pond and their geological structure. Legend: part (1) and (2) = a—alluvial fans; part (3) = (A)—range of a beaver pond, (B)—alluvial fan sands, (C)—microterrace sands, (D)—mineral–organic silt, (E)—channel sands, (F)—bottom of the valley. (A-A’) is the geological cross-section.
Figure 3.
Example of alluvial fans and their distribution in beaver pond 3 and a sketch with the distribution of forms in a beaver pond and their geological structure. Legend: part (1) and (2) = a—alluvial fans; part (3) = (A)—range of a beaver pond, (B)—alluvial fan sands, (C)—microterrace sands, (D)—mineral–organic silt, (E)—channel sands, (F)—bottom of the valley. (A-A’) is the geological cross-section.
Figure 4.
Example of levees and their distribution in beaver pond 6 and a sketch with the distribution of forms in a beaver pond and their geological structure. Legend: part (1) and (2) = a—levees; part (3) = (A)—range of a beaver pond, (B)—mineral–organic silt, (C)—levee sands, (D)—channel sands, (E)—bottom of the valley. (A-A’) is the geological cross-section.
Figure 4.
Example of levees and their distribution in beaver pond 6 and a sketch with the distribution of forms in a beaver pond and their geological structure. Legend: part (1) and (2) = a—levees; part (3) = (A)—range of a beaver pond, (B)—mineral–organic silt, (C)—levee sands, (D)—channel sands, (E)—bottom of the valley. (A-A’) is the geological cross-section.
Figure 5.
Example of sandy shadow dunes and their distribution in beaver ponds 12 and 13 and a sketch with the distribution of forms in a beaver pond and their geological structure. Legend: part (1) = a—sandy shadow dunes; part (2) = (A)—range of a beaver pond, (B)—mineral–organic silt, (C)—channel sands, (D)—sandy shadow dune sands, (E)—bottom of the valley, (F)—shore line before erosion, (G)—shore line after erosion. (A-A’) and (B-B’) are the geological cross-sections.
Figure 5.
Example of sandy shadow dunes and their distribution in beaver ponds 12 and 13 and a sketch with the distribution of forms in a beaver pond and their geological structure. Legend: part (1) = a—sandy shadow dunes; part (2) = (A)—range of a beaver pond, (B)—mineral–organic silt, (C)—channel sands, (D)—sandy shadow dune sands, (E)—bottom of the valley, (F)—shore line before erosion, (G)—shore line after erosion. (A-A’) and (B-B’) are the geological cross-sections.
Figure 6.
Example of microterraces and their distribution in beaver pond 9 and a sketch with the distribution of forms in a beaver pond and their geological structure. Legend: part (1) and (2) = a—microterraces; part (3) = (A)—range of a beaver pond, (B)—channel sands, (C)—mineral–organic silt, (D)—levee sands, (E)—bottom of the valley, (F)—alluvial fan sands, (G)—microterrace sands. (A-A’) and (B-B’) are the geological cross-sections.
Figure 6.
Example of microterraces and their distribution in beaver pond 9 and a sketch with the distribution of forms in a beaver pond and their geological structure. Legend: part (1) and (2) = a—microterraces; part (3) = (A)—range of a beaver pond, (B)—channel sands, (C)—mineral–organic silt, (D)—levee sands, (E)—bottom of the valley, (F)—alluvial fan sands, (G)—microterrace sands. (A-A’) and (B-B’) are the geological cross-sections.
Figure 7.
Examples of sedimentary structures in geomorphological forms formed in beaver ponds in Gajdówka valley. Geological structure in forms: (A)—alluvial fan, (B)—levee, (C)—sandy shadow dune sands, (D)—microterrace. (1)—levee sands with dark laminate mineral–organic silt, (2)—alluvial fan sands, (3)—mineral–organic silt, (4)—sandy shadow dune sands, (5)—microterrace sands, (6)—alluvial sands.
Figure 7.
Examples of sedimentary structures in geomorphological forms formed in beaver ponds in Gajdówka valley. Geological structure in forms: (A)—alluvial fan, (B)—levee, (C)—sandy shadow dune sands, (D)—microterrace. (1)—levee sands with dark laminate mineral–organic silt, (2)—alluvial fan sands, (3)—mineral–organic silt, (4)—sandy shadow dune sands, (5)—microterrace sands, (6)—alluvial sands.
Figure 8.
Mineral deposits (1—sands) of the accumulation fan in beaver pond 3 in Gajdówka valley.
Figure 8.
Mineral deposits (1—sands) of the accumulation fan in beaver pond 3 in Gajdówka valley.
Figure 9.
Sediments of the beaver pond (black color) after draining the water (pond 6) in Gajdówka valley.
Figure 9.
Sediments of the beaver pond (black color) after draining the water (pond 6) in Gajdówka valley.
Figure 10.
Grain-size distribution curves of mineral deposits from forms accumulated in beaver ponds. Numbers of samples 1–5 are from
Table 3.
Figure 10.
Grain-size distribution curves of mineral deposits from forms accumulated in beaver ponds. Numbers of samples 1–5 are from
Table 3.
Figure 11.
Examples of points of supply of mineral sediments to the watercourse induced by beavers in Gajdówka valley. Legend: part (A) = 1—sands from beaver burrow, 2—entrance to beaver burrow; part (B) = 1—erosion hollow.
Figure 11.
Examples of points of supply of mineral sediments to the watercourse induced by beavers in Gajdówka valley. Legend: part (A) = 1—sands from beaver burrow, 2—entrance to beaver burrow; part (B) = 1—erosion hollow.
Figure 12.
Examples of beaver burrows from the Gajdówka valley. Legend: part (A) = 1—active beaver burrow, 2—sticks with beaver teeth marks; part (B) = 1—fossil beaver burrow, 2—sticks with beaver teeth marks.
Figure 12.
Examples of beaver burrows from the Gajdówka valley. Legend: part (A) = 1—active beaver burrow, 2—sticks with beaver teeth marks; part (B) = 1—fossil beaver burrow, 2—sticks with beaver teeth marks.
Figure 13.
Increase in sediment in a beaver pond after beavers leave the habitat in Gajdówka valley (pond 3). Legend: part (A) and (B) = 1—sands, 2—mineral–organic silt.
Figure 13.
Increase in sediment in a beaver pond after beavers leave the habitat in Gajdówka valley (pond 3). Legend: part (A) and (B) = 1—sands, 2—mineral–organic silt.
Figure 14.
Filling of the ponds with mineral sediments in Gajdówka valley. Beaver pond 8 was filled with water up to the dam crest (A) in autumn 2008. In the spring of 2009, it was drained (B). In autumn 2009 (C), mineral sediments filled the pond, raising the level of the channel by 50 cm (D).
Figure 14.
Filling of the ponds with mineral sediments in Gajdówka valley. Beaver pond 8 was filled with water up to the dam crest (A) in autumn 2008. In the spring of 2009, it was drained (B). In autumn 2009 (C), mineral sediments filled the pond, raising the level of the channel by 50 cm (D).
Table 1.
Morphometric features of beaver ponds and accumulated sediments in the Gajdówka valley.
Table 1.
Morphometric features of beaver ponds and accumulated sediments in the Gajdówka valley.
Number of Pond | Type of Beaver Pond | Length–Height–Width of the Dam (m) | Morphometric Parameters of Beaver Ponds | Average Sediment Thickness (m) | Rate in cm/Year | Average Sediment Volume (m3) | Duration of Pond Existence in Years or Months | Dominant Type of Sediment 1 |
---|
Maximum Length (m) | Average Width (m) | Area (m2) |
---|
1 | floodplain | 26.5–0.6–1 | 26 | 25.5 | 600 | 0.01 | 12 | 6 | 1 year | MOS |
2 | floodplain | 26.5–0.8–1.3 | 200 | 47.5 | 11,000 | 0.09 | 54 | 99 | 6 years | MOS/S |
3 | floodplain | 26.5–1–1.5 | 32 | 21 | 570 | 0.07 | 35 | 40 | 5 years | S/MOS |
4 | floodplain | 15–0.6–1 | 26 | 15 | 300 | 0.03 | 9 | 9 | 6 months | MOS/S |
5 | channel | 3–0.3–0.5 | 11 | 2.5 | 25 | 0.03 | 36 | 0.75 | 1 year | S |
6 | floodplain | 2–1–1.5 | 35 | 6 | 300 | 0.05 | 11 | 15 | 3 months | S/MOS |
7 | channel | 0.8–0.8–1.3 | 13 | 0.7 | 13 | 0.28 | 63 | 3.6 | 3 months | S |
8 | floodplain | 4–0.5–1 | 15 | 4.8 | 57 | 0.14 | 28 | 9 | 2 years | S |
9 | floodplain | 15–0.5–1 | 35 | 13 | 430 | 0.09 | 27 | 38.7 | 3 years | MOS/S |
10 | floodplain | 4–1–1.5 | 5 | 5 | 25 | 0.01 | 12 | 0.25 | 1 month | S |
11 | floodplain | 4–1–1.3 | 5 | 4.5 | 23 | 0.01 | 12 | 0.23 | 1 month | S |
12 | floodplain | 4–1–1.2 | 5 | 4.5 | 23 | 0.03 | 2 | 0.7 | 1 month | S |
13 | floodplain | 4.5–1–1.4 | 5 | 5 | 25 | 0.03 | 2 | 0.75 | 1 month | S |
14 | floodplain | 5–1–1.5 | 18 | 4.8 | 100 | 0.28 | 84 | 2.8 | 3 years | S |
15 | floodplain | 5–0.8–1.3 | 15.5 | 5.1 | 90 | 0.05 | 15 | 4.5 | 3 years | S |
16 | floodplain | 8–1.2–1.6 | 35 | 8.7 | 250 | 0.07 | 21 | 17.6 | 3 years | S/MOS |
17 | floodplain | 7–0.8–1.3 | 36 | 6.3 | 252 | 0.02 | 4 | 5 | 2 years | MOS/S |
| | Total | | | 14,083 | | | 252.88 | | |
Table 2.
Morphometric characteristics of forms and the location of forms in individual ponds in the Gajdówka valley.
Table 2.
Morphometric characteristics of forms and the location of forms in individual ponds in the Gajdówka valley.
Number of Pond | Type of Beaver Pond | Alluvial Fan 1 | Levees 1 | Sandy Shadow Dunes 1 | Microterraces 1 | Morphometry of Forms |
---|
Length (m) | Width (m) | Height/ Thickness of Sediments (m) |
---|
1 | floodplain | − | − | − | − | − | − | − |
2 | floodplain | + | − | − | − | 3 | 2 | 0.03 |
3 | floodplain | + | − | − | − | 5 | 3 | 0.05 |
4 | floodplain | + | − | − | | 3 | 2 | 0.03 |
| | | + | 1 | 0.1–0.5 | 0.05 |
5 | channel | − | − | − | − | − | − | − |
6 | floodplain | − | + | − | − | 10 | 0.2–0.7 | 0.25 |
7 | channel | − | − | − | − | − | − | − |
8 | floodplain | + | | − | | 3 | 2 | 0.03 |
| + | | | 5 | 0.2–0.5 | 0.15 |
| | | + | 8 | 0.1–0.3 | 0.1 |
9 | floodplain | + | | − | | 5 | 3 | 0.05 |
| + | | | 12 | 0.2–0.6 | 0.2 |
| | | + | 20 | 0.1–0.6 | 0.1 |
10 | floodplain | − | − | − | − | − | − | − |
11 | floodplain | − | − | − | − | − | − | − |
12 | floodplain | − | − | + | − | 2 | 0.2–0.7 | 0.2 |
13 | floodplain | − | − | + | − | 3 | 0.2–0.7 | 0.2 |
14 | floodplain | + | − | − | − | 4 | 3 | 0.03 |
15 | floodplain | + | − | − | | 3 | 2 | 0.03 |
| | | + | 2 | 0.1–0.3 | 0.05 |
16 | floodplain | + | | − | | 5 | 2 | 0.05 |
| + | | | 10 | 0.2–0.5 | 0.15 |
| | | + | 10 | 0.1–0.4 | 0.05 |
17 | floodplain | + | − | − | − | 3 | 2 | 0.03 |
Table 3.
Grain size analysis results of sediments collected from forms occurring in beaver ponds in the Gajdówka valley.
Table 3.
Grain size analysis results of sediments collected from forms occurring in beaver ponds in the Gajdówka valley.
Sample Number | Types of Sediments and Forms | Percentage Part of the Fraction Range by the Wentworth Scale [59] (in mm) |
---|
>2.00 | 1.0–2.0 | 0.5–1 | 0.25–0.5 | 0.125–0.25 | 0.063–0.125 | <0.063 |
---|
1 | Sand, Alluvial fan, pond 3 | 0.65 | 0.93 | 4.16 | 32.52 | 46.17 | 12.12 | 3.44 |
| % cumulative | 0.65 | 1.58 | 5.75 | 38.26 | 84.44 | 96.56 | 100.00 |
2 | Sand, Alluvial fan, pond 3 | 0.00 | 0.34 | 4.64 | 41.82 | 47.50 | 5.58 | 0.12 |
| % cumulative | 0.00 | 0.34 | 4.98 | 46.80 | 94.30 | 99.88 | 100.00 |
3 | Sand, Levees pond 8 | 0.00 | 0.26 | 5.88 | 38.74 | 48.67 | 6.34 | 0.12 |
| % cumulative | 0.00 | 0.26 | 6.14 | 44.88 | 93.55 | 99.88 | 100.00 |
4 | Sand, Levees pond 9 | 0.00 | 0.27 | 5.67 | 37.93 | 45.46 | 10.11 | 0.55 |
| % cumulative | 0.00 | 0.27 | 5.95 | 43.88 | 89.33 | 99.45 | 100.00 |
5 | Sand, Alluvial fan, pond 4 | 0.00 | 0.15 | 0.99 | 11.78 | 58.24 | 26.90 | 1.94 |
| % cumulative | 0.00 | 0.15 | 1.14 | 12.92 | 71.16 | 98.06 | 100.00 |
Table 4.
Sedimentological indicators (mean grain size and sorting) samples from Gajdówka valley.
Table 4.
Sedimentological indicators (mean grain size and sorting) samples from Gajdówka valley.
Sedimentological Indicators (Folk and Ward (1922) Method) | Samples Number |
---|
1 | 2 | 3 | 4 | 5 |
---|
Mean grain size (Mz) | 2.187 | 2.038 | 2.055 | 2.094 | 2.721 |
fine-grained sand | fine-grained sand | fine-grained sand | fine-grained sand | fine-grained sand |
Sorting (¦Ň) | 0.880 | 0.702 | 0.754 | 0.817 | 0.741 |
moderately sorted | moderately sorted | moderately sorted | moderately sorted | moderately sorted |