A quantitative assessment of the contribution of small standing water bodies to the European waterscapes – case of Estonia and France

Abstract

The abundance and properties of small standing water bodies (SSWB) is globally not well known for their ecological importance is undervalued and their detection suffers from technical limitations. In the current study, we used a combination of GIS-based methods (satellite, orthophoto, ground validation) to evaluate regional estimates of standing water body (SWB) inventories in two geographically different parts of Europe – France, and Estonia. In our study the SWBs surface area threshold limit was 0.00001 km2, exceeding the limits of previous studies (>0.002 km2). The total number of SWBs in Estonia is 111 552 (2.5 per km2) and in France 598 371 (1.1 per km2). Our estimates show that the median size of SWBs in Estonia and France is 0.0003 km2 and 0.0007 km2 respectively, meaning that most of the SSWBs are not included in the global inventories, and their number is therefore underestimated. SSWBs (area below 0.01 km2) form a significant share of the total shoreline length of SWBs, 70.3% in Estonia and 58.8% in France. As nearshore areas are often very productive with diverse habitats, the SSWBs hold a crucial role in maintaining biodiversity. Our results provide quantitative evidence that SSWBs are vital and abundant landscape elements, freshwater resources, and habitats that should not be ignored in global inventories.

L’empreinte stagnustre. Un indicateur spatial au service de la compréhension limnique – le cas de la France

“…N'ayant pas pu avoir accès à celui danois (site Soer), nous ne disposons pas de la cartographie précise permettant d'ajuster les calculs d'empreinte stagnustre. En revanche, à l'échelle de l'Estonie, grâce aux travaux de l'Estonian Topographic Database, retranscrits par J. Terasmaa dans deux articles (Terasmaa, 2018 ;Terasmaa et al, 2019), nous avons pu montrer l'énorme impact sur la compréhension stagnustre d'une amélioration des localisations des étangs, ce paramètre jouant davantage sur la densité stagnustre que sur celui de la stagnucité qui au final, malgré la hausse conséquente du nombre d'étangs, bouge assez peu.…”

“…Aux échelles régionales, les travauxde Kuusisto & Raatikainen (1988) en Finlande,Bartout & Touchart (2013) en France ouTerasmaa et al (2019) en Estonie vont dans le même sens, apportant même une précision bien plus fine (moins de 100 m²).…”

Characterization of the water bodies of Extremadura (SW Spain)

“…The following parameters were calculated for each size class: total count, area, and perimeter. The same classification system has been already used in other countries such as France, Finland, and Estonia (Terasmaa et al, 2019). Results have been discussed and compared with other works at larger scales.…”

“…Estimating the storable water using GIS and remote sensing can be a feasible solution for small areas such as a single farm (< 1000 ha) or municipality (< 100 km 2 ) (Abijith et al, 2020;Al-Khuzaie et al, 2020;Duarte et al, 2014;Rashash & El-Nahry, 2015;. Technical limitations arise when the target of the study is a large land surface area such as, for instance, the region of Extremadura (41,634 km 2 ) (Terasmaa et al, 2019). An accurate delimitation of the WBs, even of the bigger ones, can be problematic (Tymków et al, 2019), since the hydrological network provided by topographic maps is not perfectly accurate, and digitizing missing water bodies turns quite laborious.…”

“…It is well-known that SWBs are usually better suited to support freshwater species, in some contexts, than rivers or large lakes (Oertli et al, 2009). According to Terasmaa et al (2019), even less diverse SWBs (e.g., bog pools) often support unique plant and animal species and contribute better to the habitat diversity. Mendonça et al (2017) concluded that SWBs, particularly agricultural ponds, can sequester more organic carbon per unit area than larger WBs.…”