1 Water Quality of Potholes in Agricultural Landscapes of East-Brandenburg (Germany) Centre for Agricultural Landscape and Land Use Research (ZALF) Thomas Kalettka 1 & Catrin Rudat 2 1 ZALF, Institute for Hydrology, 2 Umweltplan Stralsund Gmbh,

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3 Dynamics of water quality parameters of potholes - Electric conductivity - Electrolyte poor potholes: B_BAP, E_20, E_19 Electrolyte rich potholes: E_6, B_205, L_17f

4 very softly 0-4°dH softly: 4-8°dH moderate hard:8-12°dH fairly hard: 12-18°dH hard: 18-30°dH very hard: >30°dH Water quality parameters of potholes - Electrolyte pollution -

5 Dynamics of water quality parameters of potholes - bioproduction and matter dynamics - Polytrophic pothole B-BFA Characteristics of potholes eutrophication : - summer period: dense hydrophyte stands with reduced species number - winter period: maximum of algae - cyclic reduced oxygen: internal matter loading from the sediment

6 Correlation between phytoplancton and macrophytes Macrophytes dominant Macrophytes not dominant

7 Analysis of bioavailability of phosphorus from sediments Extraction- solution Extraction time [h] / temp. [°C] Bindung forms of P NH 4 Cl (1 M)0,5 / 20-25SRP / NRPGelöste, unmittelbar verfügbare Phosphate = im Interstitialwasser und labil an Oberflächen gebunden BD (0,11 M)0,5 / 40SRP NRP Reduktant lösliche anorg. Phosphate = an Fe- und Mn- Hydroxide adsorptiv gebunden: Fe(OH) 3, FeOOH, MnOOH An Fe- und Mn-Hydroxide gebundener org. P NaOH (1 M)16 / 20-25SRP NRP Baselösliche Phosphate = an Metalloxide von Fe und Al gebunden und gegen OH - austauschbar (Fe 2 O 3, Al 2 O 3 ) P in Mikrorganismen, Detritus und Huminstoffen HCl (0,5 M)16 / 20-25SRP NRP Säurelösliche Phosphate = Ca- u. Mg-P, Apatit-P Säurelabiler org. P, hydrolysierter org. P Residual-PTPSchwer abbaubare bzw. nicht verfügbare Phosphate = Refraktärer überwiegend org. P SRP = Soluble Reactive PNRP = Not Reactive P (NRP= TP-SRP)TP = Total P bioavailabilitya) direct available PSRP of the NH4Cl-extract of Pb) reductive available PSRP of the BD-extract c) total available Psum SRP of the extracts d) not available Presidual-P

8 1: B-BAP; 2: B-II/8; 3: B-KP; 4: E-19; 5: L-18b; 6: E-6; 7:E.20; 8: L-18; 9: B-BFA; 10: B-207c; 11: B-203 Internal eutrophication by release of phosphorus from sediments increasing of redox sensitive potential for P-release Redox soluble Fe(III) bound phosphorus in the sediment Classification of the eutrophication potential of aquatic pothole sediments Matter loding dispositionBD-SRP (upper 1 cm) [mg/g DM] Redox sensitive eutrophication potential high to very high (4-6)> 1.0very high moderate (2-4) moderate to high low (0-2) low very low (<0)0-0.1very low

9 VariablesFactor 1Factor 2 Electric Conductivity0,95 0,09 SO40,87 -0,27 Cl0, Ca0,98 -0,01 Mg0,96 0,01 Total water hardness0,97 0,05 pH 0,08 0,82 O2 0,15 0,91 TP 0,14 -0,64 Explained Varianz (Own value) 5,362,00 Share of total varianz % 602 Extraction: Mean components; factor rotation: varimax; Results: Factor loadings of variables marked loadings 0,65 Hydrochemical main parameters of potholes in agricultural landscapes High, significant correlation (p < 0,05) at 9 from 16 Parameters PCA-Ordination plot of extracted variables in correlation to 39 potholes Group 1: P-rich Mineral-poor Group 2: P-poorMineral-poor Group 3:P-richMineral-rich Group 4:P-poorMineral-rich

10 Wasser quality (trophic level) of potholes in agricultural landscapes (modified method by Klapper 1992) Lietzen (n=15), Eggersdorf (n=15), Müncheberg incl. Eggersdorf (n=59) (2,5-2,9 = eutroph; 3,0-3,4 = high eutroph; 3,5-3,9 = polytroph; 4,0-4,4 = high polytroph) low trophic level within arable land = low matter loading disposition big potholes with wide buffer strips (high buffer capacity) small potholes within small slightly rolling catchment (low soil erosion) lacking of input from drainages soil ramparts at the upper shore (high buffer capacity)

11 Correlation between trophic level and matter loading disposition of potholes n = 29; r = 0,79; significant p < 0,001 Assessment of matter loding disposition (MLD) by score system: MLD = Total (matter loading factors) – Total (buffer capacity of pothole) Sum of points catchment area (1-5) catchment relief (1-5) input by drainage (1-3) input by water erosion (1-4) buffer strip width (1-5) shore width (1-5) soil ramparts at shore top (1-5) pothole area (1-5)

12 Trophic level Parameters oligo- trophic meso- trophic weak eutrophic high eutrophic weak polytr. high polytr. hyper- trophic 1,0-1,41,5-2,52,5-2,93,0-3,43,5-3,94,0-4,44,5-5,0 Nutrients Spring, MV 3-4, after melting of ice cover [mg/l] a) SRP b) TP c) anorganic N (if TN/TP < 7) </= 0,005 </= 0,015 </= 0,3 </= 0,015 </= 0,045 </= 0,5 </= 0,2 </= 0,3 </= 1,0 </= 1,2 </= 1,5 > 1,2 > 1,5 Summer, MW 6-9 [mg/l] a) SRP b) TP c) anorganic N (if TN/TP < 7) </= 0,002 </= 0,015 </= 0,01 </= 0,005 </= 0,04 </= 0,03 </= 0,1 </= 0,3 </= 0,1 </= 0,5 > 0,5 Bioproduction Chl. A, MV 3-11, after melting of ice cover [mg/l] Only if macrophytes not dominant 1*</= 3</= 10</= 40</= 60> 60 Macrophytes/filamentous green algae 2* Visible depth, MV 3-11 [m] After melting of ice cover, use only if water level is deep enough for whole year ->/= 4>/= 1,5>/= 1,0>/= 0,5>/= 0,2< 0,2 Water quality classification of potholes (modified after Klapper 1992) 1* - Sum coverage of macrophytes + filamentous green algae </= 50 % 2* - Coverage % of whole surface water area with litoral charakter (maximum of vegetation period), Trophic level indication by species combinations, use only if sum of coverage of macrophytes/filamentous green algae >/= 25 %

13 Species nameTrophic level N*NO3NH4PI° Floating covers / pleustophytes Lemna gibba3-48rich Lemna minor2, ,0 Spirodela polyrhiza(2)-36rich5,0 Wolffia arrhiza36 Suspendes mats / pleustophytes Lemna trisulca(2)-3-(4)5moderate Ceratophyllum submersum(2)-3, 47 Ceratophyllum demersum(2)-3, 48rich Fadengrünalgen3-4 Riccia fluitans2-2,9poormoderate Utricularia vulgaris2-34poor- moderate Rooted floating leaf lawn / rhizophytes Nuphar lutea Potamogeton natans1-352,5 Ranunculus aquatilis36 Polygonum amphibium2-3-44not rich Rooted submersed plants /rhizophytes Potamogeton crispus3-454,5 Potamogeton acutifolius36 Myriophyllum spicatum2,5-3-47not rich3,0 Hottonia palustris2-34not high Trophic level indication of standing waters by hydrophytes (literature) N* = Ellenberg et al. (1991) I° = Melzer (1988)

14 level Lemna gibba Lemna minor Lemna trisulca Spirod. polyrhiza Cer. submersum Cer. demersum Utric. vulgaris Fadengrünalgen Riccia fluitans Nuphar luta Nymphaea alba Pol. amphibium Pol. natans Pol. crispus Pot. acutifolius Chara fragilis 4,5Cer. submersum Fadengrünalgen ,0Lemna gibba ,0Cer. submersum ,5Lemna minor Spirodela polyrhiza ,5Wolffia arrhiza ,5Cer. submersum ,0Cer. submersum ,0Lemna minor Spirodela polyrhiza ,0Myr. Spicatum Nuphar lutea ,0Ran. aquatilis ,0Hottonia palustris Tro- phic Dominant species *coverage [%] Accompanying species *max. coverage [%] Preliminary trophic level indikation of potholes by hydrophytes *Coverage in % of whole water area with litoral charakter (maximum May to September)

15 Correlation between matter loadings and biodiversity of macrophytes Problem: Shortage of weak eutrophic reference sites in the agricultural landscape n = 32; r =0,59; significant p < 0,001n = 32; r = 0,64; significant p < 0,001 n = 32; r = 0,38; significant p < 0,02n = 32; r = 0,19; nicht significant

16 Correlation between water quality and surface sediment pollution n = 22; r = 0,76; significant p < 0,001 n = 22; r = 0,66; significant p < 0,005 n = 22; r = 0,54; significant p < 0,01 Problems: influence of soil erosion and wet-dry cycle on mud formation (silicate muds) shortage of weak eutrophic reference sites in the agricultural landscape

Influence of runoff in winter period on trophic level of potholes in agricultural landscapes with middle to high matter loading disposition 1 = low runoff3 = snowmelt, high runoff, frozen soil 2 = rain, high runoff, soil not frozen4 = snow/rain, thawing soil, middle runoff