Optimization of grassland management with consideration for meadow bird conservation in the Middle Elbe Biosphere Reserve

In recent decades, there has been a significant decline in the populations of characteristic meadow bird species in the floodplain grasslands along the middle Elbe. The management of these grasslands often differs considerably in terms of the methods used (mowing and mowing-grazing), the frequency of use, and the timing of management. The influence of such differences on the conservation status of fireweed floodplain meadows (LRT 6440) and lowland hay meadows (LRT 6510) as well as on the occurrence of meadow breeders in these habitat types (LRT) is still insufficiently known.

Based on a comprehensive status analysis, proposals for optimizing grassland management will be developed, taking into account the protection of meadow breeders. The focus is on developing and describing practical, goal-oriented, and implementable solutions for site-specific management that contribute to the preservation and improvement of the LRTs under investigation and to the positive population development of valuable meadow breeders such as the lapwing, meadow pipit, whinchat, yellow wagtail, Montagu’s harrier, corncrake, and short-eared owl.

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Project priorities

Grassland management, meadow breeders

Project region

The areas investigated as part of this project are spread across a total of four Natura 2000 sites between the villages of Dornburg (Gommern) and Vockerode (see Fig. 1):

• Elbaue zwischen Saalemündung und Magdeburg (FFH0050)
• Elbaue Steckby-Lödderitz (FFH0054)
• Dessau-Wörlitzer Elbauen (FFH0067)
• Kühnauer Heide und Elbaue zwischen Aken und Dessau (FFH0125)

With the exception of the NATURA 2000 site „Elbaue zwischen Saalemündung und Magdeburg (FFH0050)“, these are also part of the European bird sanctuary „Mittlere Elbe einschließlich Steckby-Lödderitzer Forst (SPA0001)”. All areas are located in the Middle Elbe Biosphere Reserve. Isolated parts of the area are designated as nature reserves (NSG0036, NSG0394). The areas studied cover a total of approximately 700 hectares.

Further project details

• Work package 1

  Condition analysis of species composition (avifauna) and habitats (FFH-LRT 6510, 6440). Conducting comprehensive studies on the relationships between vegetation structure, types of use, and the occurrence of meadow birds

  Vegetation surveys were conducted on 46 macroplots before the first and second mowing. Furthermore, between the beginning of April and the beginning of July 2021, breeding bird mapping was carried out on the 46 selected study areas in seven day visits as territory mapping according to SÜDBECK et al. 2005. All bird species of open and semi-open land (especially grassland) were recorded, as well as species classified as rare or (potentially) endangered according to the Red List of Saxony-Anhalt or Germany. A focus was placed on documenting ground-nesting species.

  In addition, night surveys focusing on calling corncrake males were carried out in May and June 2021 between dusk and dawn as point-stop surveys using sound decoys (cf. Schulze 2015) to record possible corncrake occurrences. Based on the initial results of the 2021 territory mapping, 13 territories of the skylark (Alauda arvensis) and, from the beginning of June, an additional eight territories of the whinchat (Saxicola rubetra) were examined for breeding success from the beginning of May to the end of July, and a land use analysis was prepared. At the end of May and the end of July 2021, relevant vegetation structures were recorded to characterize the habitats of selected bird species. In addition, the landscape structures and features relevant to bird species in open and semi-open habitats were recorded throughout the entire project area.

  In addition to vegetation structure surveys on the ground, vegetation height was derived from remote sensing data on selected floodplain meadows near Waldersee. This should enable a comparison of traditional ground mapping with a digital surface model generated from drone images and also provide information on the practical relevance of this method. Utilization times and management methods are documented in order to analyze the influence of different management methods on vegetation and breeding birds. For site characterization and further interpretation of the vegetation data, soil samples were taken on all study areas in the fall of 2021.

  

  

  

  

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• Work package 2

  Proposals for optimizing grassland management while taking into account the protection of meadow-breeding birds, based on the status analysis carried out in WP 1

  In consultation with the relevant nature conservation authorities, the Mittelelbe Biosphere Reserve, and the WWF, proposals are to be drawn up for the site-specific management of FFH-LRTs with a view to maintaining and improving their conservation status and protecting and promoting meadow birds.

  

  

  

  

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• First results

  Vegetation

  A total of 244 vascular plant species were identified during the two surveys conducted in 2020 on the 46 macroplots examined. The areas in all four study areas were characterized by a fairly similar basic stock of fourteen species, such as tufted vetch (Vicia cracca), white bedstraw (Galium album), and meadow vetchling (Lathyrus pratensis) (consistency > 90%). The median total number of species on the 46 macroplots was 60. There was only a slight difference in species numbers between the areas, with Dornburg having the lowest species richness (median of 53) and the floodplain near Waldersee having the highest species richness (median of 68 species). The latter area also had the most species-rich macroplot of all areas, with a total of 114 species.

  LRT status and species numbers in relation to land use

  On the macroplots studied, no clear correlation between the type of land use (mowing (M), mowing with cattle (MWR)/sheep (MWS)) and the EHZ of LRT 6510 and 6440 was apparent after the first year of study (Fig. 2). For the majority of macroplots, the EHZ of the respective LRT was classified as “good” (B). Macroplots rated as “excellent” (A) were either exclusively mowed or used as cattle grazing land (n = 8). Only one of the 46 macroplots did not have LRT status due to its impoverished species inventory.

  

  When looking at the subcriterion species inventory (Fig. 2), it becomes clear that the majority of cattle grazing pastures (78%; n = 27) and pure mowing areas (67%, n = 9) have an excellently developed species inventory (A). In contrast, only 22% of sheep hay meadows (n = 9) were rated A. However, this result does not necessarily indicate a negative impact of sheep grazing – rather, differences between the study areas may be at play here: The majority of sheep grazing pastures are located in the Dornburg floodplain, which could differ from the other areas due to its soil conditions, for example. The evaluation of the soil analyses will provide more detailed information to clarify this question.

  A variety of structural parameters directly or indirectly related to land use influence the vegetation of grassland. Higher grass cover, which is the result of more intensive farming practices (fertilization, higher cutting frequency), also had a negative effect on the number of characteristic species of the respective LRT in the macroplots studied, especially in LRT 6510 (Fig. 3a/b).

  

  Open ground had a slightly positive influence on the total number of species and the number of characteristic species, as disturbances such as those caused by hoofprints can serve as establishment niches (germination sites) for various herbs (Fig. 4). In general, however, the influences of the above-mentioned and other structural parameters (e.g., litter layer height, horizontal transparency) on species numbers have so far been rather weak, or no correlation could be established.

  

  

  

  

  

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  breeding bird mapping

  A total of 68 relevant bird species were recorded in the study area in 2021. Characteristic small meadow breeders recorded in the study areas (exclusively agricultural grassland without edge structures) included, in particular, the skylark (Alauda arvensis), corn bunting (Emberiza calandra), stonechat (Saxicola rubicola), whinchat (Saxicola rubetra), and yellow wagtail (Motacilla flava flava) were identified as breeding birds. Yellowhammer (Emberiza citrinella) and red-backed shrike (Lanius collurio) also occurred with greater regularity in the areas. The most frequent visitors for feeding were the starling (Sturnus vulgaris) and the barn swallow (Hirundo rustica). With the exception of a few observations of lapwings (Vanellus vanellus) and a snipe (Gallinago gallinago), no large meadow breeders were recorded. While a similarly high number of bird species was recorded in the study areas in the Dornburg floodplain, the Großkühnau floodplain, and the floodplain near Waldersee, the number of species in the Steutz floodplain was only about half as high (Fig. 5).

  

  Detection of breeding evidence and, if applicable, nesting sites

  In approximately 50% of the observed whinchat and skylark territories, breeding could be confirmed through behavioral and spatial use analysis (see Fig. 6). At least 60% of whinchats and at least 30% of skylarks were confirmed to have successfully bred. In the remaining territories, the suspected territory formation could not be confirmed (unpaired males), the territory was abandoned, or the pair showed no signs of breeding during the observation period.

  

  Bird-relevant landscape structure parameters

  The number of structure types recorded varied greatly between the sub-areas. In Waldersee, a total of 33 structure types were recorded in 2021, while in Dornburg and Großkühnau, lower values of 30 and 27 structure types respectively were recorded. The lowest structural diversity, with only 14 structural types, was found in the Steutz sub-area. Similar results were found for the average structural diversity within the sub-areas (Fig. 7). The predominant structural type in all areas was grassland, with a share varying between around 82% in Waldersee and 99% in Steutz (Fig. 8). The proportions of the other structural types are very diverse compared to grassland. Outside the commercial grassland, in the 50 m buffer zone of the study area, the Dornburg sub-area is dominated by forest areas, ditches with perennial vegetation, arable land, and paved paths. In Großkühnau, there is a comparatively high proportion (0.9%) of wet depressions. These stand out from the rest of the grassland due to the vegetation that prevails there (wetness indicators such as sedges and rushes). In Steutz, due to the very high proportion of grassland, all other structure types occur only to a minor extent. In Waldersee, woody plants are the dominant structure type alongside grassland. They are characterized by tall, extensive woody plants with and without undergrowth, as well as young succession stages.

  

  Effects of different landscape structures on characteristic meadow birds

  Initial results of the land use analysis and the influence of landscape structures on characteristic meadow birds show that 91.6% of skylarks were mapped on grassland. Two percent of skylarks were found in depressions in grassland, hollows in grassland, or wet hollows. All other types of structures used accounted for less than 1% each.

  As with skylarks, the most frequently used structure type by yellowhammers (41.1%) is grassland. Furthermore, corn buntings were increasingly observed on individual trees (13.8%), tall individual trees with undergrowth (11.4%), and in wet depressions (7.1%). The density of corn buntings also increased with a high proportion of the aforementioned structures in the study areas.

  

  

  

  

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