TY - CHAP A1 - Eisele, Micha A1 - Bárdossy, András A1 - El Hachem, Abbas A1 - Seidel, Jochen A1 - Kröcher, Jenny A1 - Lischeid, Gunnar A1 - Pätzig, Marlene A1 - Shrestha, Rupesh A1 - Frankenberg, Philip A1 - Jüpner, Robert T1 - Nachlese vom Hydrologie Tag 2021 T2 - Hydrologie und Wasserbewirtschaftung : HyWa = Hydrology and water resources management, Germany / Hrsg.: Fachverwaltungen des Bundes und der Länder T2 - Gleanings from Hydrology Day 2021 Y1 - 2021 SN - 1439-1783 SN - 2749-859X VL - 65 IS - 6 SP - 298 EP - 298 PB - Bundesanstalt für Gewässerkunde CY - Koblenz ER - TY - JOUR A1 - Pätzig, Marlene A1 - Kalettka, Thomas A1 - Onandia, Gabriela A1 - Balla, Dagmar A1 - Lischeid, Gunnar T1 - How much information do we gain from multiple-year sampling in natural pond research? JF - Limnologica : ecology and management of inland waters N2 - Natural ponds are perceived as spatially and temporally highly variable ecosystems. This perception is in contrast to the often-applied sampling design with high spatial but low temporal replication. Based on a data set covering a period of six years and 20 permanently to periodically inundated ponds, we investigated whether this widely applied sampling design is sufficient to identify differences between single ponds or single years with regard to water quality and macrophyte community composition as measures of ecosystem integrity. In our study, the factor "pond", which describes differences between individual ponds, explained 56 % and 63 %, respectively, of the variance in water quality and macrophyte composition. In contrast, the factor "year" that refers to changes between individual years, contributed less to understand the observed variability in water quality and macrophyte composition (10 % and 7 % respectively, of the variance explained). The low explanation of variance for "year" and the low year-to-year correlation for the single water quality parameter or macrophyte coverage values, respectively, indicated high but non-consistent temporal variability affecting individual pond patterns. In general, the results largely supported the ability of the widely applied sampling strategy with about one sampling date per year to capture differences in water quality and macrophyte community composition between ponds. Hence, future research can be rest upon sampling designs that give more weight to the number of ponds than the number of years in dependence on the research question and the available resources. Nonetheless, pond research would miss a substantial amount of information (7 to 10 % of the variance explained), when the sampling would generally be restricted to one year. Moreover, we expect that the importance of multiple-year sampling will likely increase in periods and regions of higher hydrological variability compared to the average hydrological conditions encountered in the studied period. KW - water quality KW - macrophytes KW - space KW - time KW - kettle holes KW - conservation Y1 - 2020 U6 - https://doi.org/10.1016/j.limno.2019.125728 SN - 0075-9511 SN - 1873-5851 VL - 80 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Lischeid, Gunnar A1 - Kalettka, Thomas A1 - Holländer, Matthias A1 - Steidl, Jörg A1 - Merz, Christoph A1 - Dannowski, Ralf A1 - Hohenbrink, Tobias Ludwig A1 - Lehr, Christian A1 - Onandia, Gabriela A1 - Reverey, Florian A1 - Pätzig, Marlene T1 - Natural ponds in an agricultural landscape BT - external drivers, internal processes, and the role of the terrestrial-aquatic interface JF - Limnologica : ecology and management of inland waters N2 - The pleistocenic landscape in North Europe, North Asia and North America is spotted with thousands of natural ponds called kettle holes. They are biological and biogeochemical hotspots. Due to small size, small perimeter and shallow depth biological and biogeochemical processes in kettle holes are closely linked to the dynamics and the emissions of the terrestrial environment. On the other hand, their intriguing high spatial and temporal variability makes a sound understanding of the terrestrial-aquatic link very difficult. It is presumed that intensive agricultural land use during the last decades has resulted in a ubiquitous high nutrient load. However, the water quality encountered at single sites highly depends on internal biogeochemical processes and thus can differ substantially even between adjacent sites. This study aimed at elucidating the interplay between external drivers and internal processes based on a thorough analysis of a comprehensive kettle hole water quality data set. To study the role of external drivers, effects of land use in the adjacent terrestrial environment, effects of vegetation at the interface between terrestrial and aquatic systems, and that of kettle hole morphology on water quality was investigated. None of these drivers was prone to strong with-in year variability. Thus temporal variability of spatial patterns could point to the role of internal biogeochemical processes. To that end, the temporal stability of the respective spatial patterns was studied as well for various solutes. All of these analyses were performed for a set of different variables. Different results for different solutes were then used as a source of information about the respective driving processes. In the Quillow catchment in the Uckermark region, about 100 km north of Berlin, Germany, 62 kettle holes have been regularly sampled since 2013. Kettle hole catchments were determined based on a groundwater level map of the uppermost aquifer. The catchments were not clearly related to topography. Spatial patterns of kettle hole water concentration of (earth) alkaline metals and chloride were fairly stable, presumably reflecting solute concentration of the uppermost aquifer. In contrast, spatial patterns of nutrients and redox-sensitive solutes within the kettle holes were hardly correlated between different sampling campaigns. Correspondingly, effects of season, hydrogeomorphic kettle hole type, shore vegetation or land use in the respective catchments were significant but explained only a minor portion of the total variance. It is concluded that internal processes mask effects of the terrestrial environment. There is some evidence that denitrification and phosphorus release from the sediment during frequent periods of hypoxia might play a major role. The latter seems to boost primary production occasionally. These processes do not follow a clear seasonal pattern and are still not well understood. KW - Ponds KW - Kettle holes KW - Water quality KW - Land use KW - Hydrogeomorphic type KW - Shore vegetationa Y1 - 2018 U6 - https://doi.org/10.1016/j.limno.2017.01.003 SN - 0075-9511 SN - 1873-5851 VL - 68 SP - 5 EP - 16 PB - Elsevier GMBH CY - München ER - TY - JOUR A1 - Schöpke, Benito A1 - Heinze, Johannes A1 - Pätzig, Marlene A1 - Heinken, Thilo T1 - Do dispersal traits of wetland plant species explain tolerance against isolation effects in naturally fragmented habitats? JF - Plant ecology : an international journal N2 - The effects of habitat fragmentation and isolation on plant species richness have been verified for a wide range of anthropogenically fragmented habitats, but there is currently little information about their effects in naturally small and isolated habitats. We tested whether habitat area, heterogeneity, and isolation affect the richness of wetland vascular plant species in kettle holes, i.e., small glacially created wetlands, in an agricultural landscape of 1 km(2) in NE Germany. We compared fragmentation effects with those of forest fragments in the same landscape window. Since wetland and forest species might differ in their tolerance to isolation, and because isolation effects on plant species may be trait dependent, we asked which key life history traits might foster differences in isolation tolerance between wetland and forest plants. We recorded the flora and vegetation types in 83 isolated sites that contained 81 kettle holes and 25 forest fragments. Overall, the number of wetland species increased with increasing area and heterogeneity, i.e., the number of vegetation types, while area was not a surrogate for heterogeneity in these naturally fragmented systems. Isolation did not influence the number of wetland species but decreased the number of forest species. We also found that seeds of wetland species were on average lighter, more persistent and better adapted to epizoochory, e.g., by waterfowl, than seeds of forest species. Therefore, we suggest that wetland species are more tolerant to isolation than forest species due to their higher dispersal potential in space and time, which may counterbalance the negative effects of isolation. KW - Forest species KW - Habitat fragmentation KW - Isolation KW - Kettle holes KW - Life history traits KW - Wetland species Y1 - 2019 U6 - https://doi.org/10.1007/s11258-019-00955-8 SN - 1385-0237 SN - 1573-5052 VL - 220 IS - 9 SP - 801 EP - 815 PB - Springer CY - Dordrecht ER -