Strategies for the ecological optimization of grassland management for habitat types of Community interest 6440, 6510, and 6520 in Saxony-Anhalt

Project priorities

• Testing and reviewing the effects of different measures (and combinations thereof) involving mowing and fertilization on the species spectrum, vegetation structures, soil nutrient balance, and crop usability, as well as enhancement through the establishment of target species on two test areas of habitat types 6440 (floodplain meadows with fireweed) and 6510 (lowland hay meadows).
• Evaluation of selected measures from the “Voluntary Nature Conservation Services” support program on grassland in Saxony-Anhalt
• Condition analysis of vegetation composition, forage value, and soil chemical parameters of selected meadows of LRT 6510 in the South Harz Karst Landscape Biosphere Reserve
• Update of the grassland guidelines, site groups, and management recommendations for grassland habitat types 6440, 6510, and 6520 in Saxony-Anhalt
• Updating of the Internet information platform on “Grassland Management” and the “Grassland Trials” database

Project region

Saxony-Anhalt

Further project details

• management trials

  Since 2010, two management trials have been analyzing and evaluating the effects of various grassland management factors, such as different fertilization variants, mowing times and frequencies, treatment by rolling, and sowing of target species, on species composition, vegetation structure, conservation status, yield, feed value, and soil chemical properties.

  The studies are being conducted on a lowland hay meadow (LRT 6510) in the Wulfener Bruch near Köthen and a fireweed floodplain meadow (LRT 6440) at Löbben near Dessau. Both grasslands are part of the Middle Elbe Biosphere Reserve.

  The Wulfener Bruch, covering more than 1,000 hectares, is located north of the town of Köthen in the district of Anhalt-Bitterfeld and is part of the Elbe glacial valley, a few kilometers south of the Saale estuary. North of the Wulfener Bruch lies the Elbe valley lowlands around Aken and Lödderitz, and to the south lies the Köthen agricultural plain. With an altitude of between 52 and 54 m above sea level, it belongs to the lowlands of the Elbe. The landscape is characterized by agricultural land, mainly meadows and pastures. As early as the first half of the 19th century, the project area was extensively drained through land improvement measures. The area has low groundwater levels, estimated by ROCHLITZER (1993) at 0.3 to 0.8 m. These low groundwater levels and flooding with water accumulation in some areas have led to the development of an anmoorgley soil type. The majority of the project area is classified as LRT 6510 (lowland hay meadows). It is located on the edge of the “Wulfener Bruchwiesen” nature reserve, the “Diebziger Busch und Wulfener Bruchwiesen” FFH area, and the “Wulfener Bruch und Teichgebiet Osternienburg” SPA area.

  

  The Fischerhüttenwiesen near Dessau are located east of Waldersee and north of the federal highway to Vockerode and are largely surrounded by Lake Löbben, an oxbow lake. They are located in the “Mittelelbe” biosphere reserve and the “Dessau-Wörlitzer Elbauen” FFH area. It is a large area of seasonally wet grassland (approx. 67 ha) with a constant occurrence of characteristic seasonally wet meadow species (e.g. Cnidium dubium, Galium boreale, Sanguisorba officinalis), which, at least in the northern area, can be classified as habitat type 6440 and has a high species diversity and a high proportion of species characteristic of this habitat type. In terms of plant sociology, the area can be classified as Sanguisorbo officinalis-Silaetum silai Klapp 1951 (silgen-grass-meadow). The area is regularly flooded at least once a year.

  

  

  experimental variants

  Wulfener Bruch test area	Fischerhüttenwiesen test area near Dessau
  Mowing: single cut (June 15), double cut (May 1–15 / August 1–30), triple cut (May 1–15 / July 1–15 / from September 1) Fertilization: Zero fertilization, 60 kg N/ha, 120 kg N/ha, each with and without P fertilization after removal to roll Introduction of target species	Mowing: twice (June 1 / August 15), twice (June 15 / August 15), three times (silage maturity), three times (pasture maturity / July 1 / September 1) Fertilization: Zero fertilization, PK removal, 60 kg N/ha, 60 kg N/ha + PK removal, 100 kg N/ha + PK removal, 120 kg N/ha + PK removal to roll

  

  

  In order to observe the effects of the various management factors, soil chemistry, floristic species composition, vegetation structure, yield shares, and forage quality will be analyzed over a period of six years (2010–2015).

  

  

  

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• Grassland enhancement through the introduction of target species (Wulfener Bruch)

  In 2011, target species were introduced in strips on the block trial in Wulfener Bruch (see also sub-item “Management trials”). On the one hand, this leads to an enhancement of the species-poor grassland area. On the other hand, it enables the investigation of the establishment success of the target species under different management practices (mowing frequency, fertilization, rolling). As a result, recommendations can be made as to the extent to which the target species strips can be subjected to the same management as the rest of the grassland area after sowing.

  n 2010, 16 target species strips measuring 6 x 150 m were created on the area classified as habitat type 6510 (nutrient-poor lowland hay meadows) with a transition to habitat type 6440 (fireweed floodplain meadows). These were first plowed in late summer and then cultivated. The strips were then left fallow for one year before being cultivated again in the summer of 2011 to prepare the seedbed. In September, which is the appropriate sowing time for the continental regions of central Germany, 6 grass species and 22 herbs were sown. The grassland is a fairly nutrient-rich area (average values of the sample areas: pH: 6.48 (±0.68), total N % 0.74 (±0.30), P mg/100 g soil 11.31 (±7.01), K mg/100 g soil 20.90 (±5.58).

  

  

  

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  As expected, in addition to the target species, large populations of therophytes (including Capsella bursa-pastoris, Veronica arvensis) and perennial species such as Trifolium hybridum and Cirsium arvense, as well as numerous grasses from rhizomes remaining in the soil (e.g., Alopecurus pratensis, Holcus lanatus). After regular mowing in accordance with the experimental design (one to three cuts) and subsequent maintenance mowing in the fall, the areas in spring 2013 were significantly richer in herbs than the comparable control areas without sowing.

   

  

  Establishment of target species in the first year after sowing. Ninety-three percent of the introduced species grew. Only two species could not be recorded.

  

  Examples of species that were able to develop on the site in the second year as well.

  

  

  In the first year after sowing, the herbaceous target species were counted on 50 x 50 cm (0.25 m²) sample areas. Geranium pratense (meadow cranesbill), Ranunculus acris (sharp buttercup), and Galium album (white bedstraw) were particularly abundant. Some species, such as Knautia arvensis (field scabious) and Centaurea jacea (brown knapweed), only grew during the summer. It remains to be seen to what extent species that did not occur or only occurred in small numbers in the first year after sowing will develop in the second year. However, experience from many other measures to enhance species-poor meadows shows that sown species need up to three years to establish themselves

• Meadows in the “Karstlandschaft Südharz” biosphere reserve

  In 2010, site groups for FFH-LRT 6440 (floodplain meadows with fireweed), 6510 (lowland hay meadows) and 6520 (mountain hay meadows) were defined and described for Saxony-Anhalt for the first time, and initial management recommendations were made from a nature conservation perspective. Describing the characteristics of the site groups, including information on soil properties and vegetation composition, proved particularly difficult for habitat type 6510, as this type is distributed throughout the entire federal state and only limited and, in some cases, very old literature/available data could be consulted. A knowledge deficit became particularly apparent for site group 1.3 (base-rich, moderately fresh sites at the planar-colline altitude level with poor nutrient availability), which is primarily formed by the plant community of Dauco carotae-Arrhenatheretum elatioris in the subassociation salvietosum pratensis. Hundt (1958) only provides information on this association from southern Saxony-Anhalt. However, such meadows can also be found in the “Karstlandschaft Südharz” biosphere reserve, among other places. Apart from the habitat type mapping (BioLRT data) of the FFH areas located there, “Bundsandstein- und Gipskarstlandschaft bei Questenberg im Südharz” (FFH0101) and “Gipskarstlandschaft Pölsfeld und Breiter Fleck im Südharz” (FFH0108) located there, there is no data on species composition. There is no data available on soil properties (especially nutrient content) and the nutritional value of the vegetation. However, such information is extremely important for making management recommendations to ensure a favorable conservation status. On the other hand, the biosphere reserve is endeavoring to revive sheep grazing and the keeping of robust cattle breeds in order to preserve the meadows. This could restore the importance of mowing the meadows to obtain winter feed or supplementary feed for year-round outdoor grazing during periods of heavy snowfall (hay). The nutritional value of the vegetation is being studied to assess its suitability as winter feed.

  For the proposed project duration, a one-time sampling of 15-20 meadows per year is planned. Depending on the characteristics of the vegetation, 1-3 sample areas are to be established on each meadow. The sampling includes:

  • Soil sample mixed over 10 x 10 m (early spring)
  • Vegetation survey on 5 x 5 m (May/June)
  • Feed sample 1 x 1 m (May/June)

  

  First results available!

  As part of a master’s thesis at Anhalt University of Applied Sciences, the results of investigations of 38 sample areas of lowland hay meadows (LRT 6510) occurring in the South Harz Karst Landscape Biosphere Reserve were evaluated.

  You can download Katrin Henning’s master’s thesis here.

• grassland evaluation

  When evaluating grassland areas of habitat types 6210 (calcareous dry grasslands), 6440 (floodplain meadows with fireweed), 6510 (lowland hay meadows) and 6520 (mountain hay meadows) in Saxony-Anhalt, selected, well-documented measures are being implemented within the framework of the Voluntary Nature Conservation Services Program (RdErl. des MLU vom 24.1.2008 – 55.60129/4. 4.2) or within the framework of contractual nature conservation (RdErl. des MRLU vom 11.4.2002 – 55.3-60129/4.4.2, amended by RdErl. des MLU vom 10.4.2003 – 55-3-60129/4.4.2). Between 2010 and 2012, 179 areas in eleven districts of Saxony-Anhalt were already surveyed, and in 2013 up to 40 grasslands in the north are to be examined and evaluated.

  The vegetation cover of grassland areas is recorded based on the evaluation of grasslands in the Cultural Landscape Program (KULAP) in Thuringia. The species-specific yield share is estimated for all higher plants in a field block. The assessment is also based on the Cultural Landscape Program (KULAP) in Thuringia (Hochberg et al. 2003). The list of valuable grassland species used there has been modified for Saxony-Anhalt. A target/actual comparison is made to assess the condition. The proportion of valuable grassland species, the habitat structure (proportion of herbs, stratification), and impairments are taken into account.

  The evaluation results allow conclusions to be drawn about the current state of grassland in LRT 6210, 6440, 6510, and 6520 in Saxony-Anhalt under agri-environmental measures. It is difficult to draw conclusions about the effectiveness of measures under the voluntary nature conservation services and contractual nature conservation programs, as a repeat survey is still pending.

  The evaluation has shown that the grassland is very often in suboptimal condition. The biggest problems are the high proportion of grasses and the tendency towards monoculture. This is usually the result of insufficient frequency of use. Especially in high-yield locations, management within the FNL or even the VNS may be too low. As a result, very well-developed stands cannot be maintained and poorly developed stands cannot be further developed (cf. Bossard 2000, Hölzel 2003). A comparison of the evaluated measures with the management recommendations of the Saxony-Anhalt site groups according to Dullau et al. (2010) showed that the measures are not suitable for preserving or restoring meadows of high conservation value, as they do not represent the optimal management practices for the habitat types. Often, a single use is specified, but many site groups of the evaluated habitat types should be used twice or, in some cases, three times a year. Voluntary nature conservation measures aim to secure and improve the condition and diversity of biodiversity (MUL 2008) and should therefore be based on the optimal management recommendations (cf. Dullau et al. 2010). The results of the evaluation to date suggest that the extensive management promoted by the Voluntary Nature Conservation Services program does not have a beneficial effect on the species composition and population structure of the productive grasslands of LRT 6440 and 6510

  Overall rating for life dream types 6210, 6440, 6510, and 6520 (n=179) in the 2010-2012 survey period

  

  Evaluation of the sub-indicators for habitat types 6210, 6440, 6510, and 6520 (n = 179) in the 2010–2012 survey period.

  

  

  

  

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  Nutrient status of the evaluated grasslands

  In order to illustrate the nutrient status of the evaluated grasslands, unweighted nitrogen values (Ellenberg et al. 1992) were calculated based on the plant species found. The figure below shows that the values for all areas range between 7 (indicating high nitrogen content) and 2 (indicating extremely low to low nitrogen content). Looking at the box plot, it can be seen that the lowland hay meadows (LRT 6510) showed the greatest range. Most areas of this habitat type (> 81%) had an N value > 5, 26% were in the range between 6 and 7, but some areas also had a mean weighted nitrogen value of 2. These nutrient-poor areas can be attributed to the drier characteristics of LRT 6510. The majority of the fireweed floodplain meadows (LRT 6440) are also nutrient-rich. Here, the lowest values are > 4 and 62% of the areas studied had an N value > 5. The mountain hay meadows (LRT 6520) recorded significantly poorer nutrient conditions. The lowest N values were found in the calcareous dry grasslands (LRT 6210) in southern Saxony-Anhalt. The mean weighted nitrogen value there was mostly in the range of 3

  

  Conclusion and outlook

  The results of the evaluation to date suggest that the extensive farming methods promoted through the “Voluntary Nature Conservation Services” program do not have a beneficial effect on the species composition and population structure of the productive grasslands of LRT 6440 and 6510. LRT 6510 in particular, with its large number of site groups, shows a wide range of mean N values (Figure 5). There is a correlation between the mean N value and the G value (R² 0.576) as well as the overall assessment (R² 0.353). As the nutrient supply improves, the conservation value of extensive use decreases. A differentiated approach to subsidy programs would therefore be highly desirable. From a floristic point of view, productive grasslands should be suitable for two-cut use with an early first mowing date.

  The investigations on subsidized grassland areas in the state of Saxony-Anhalt will be continued as part of the project until 2013.

  The latest results of the grassland evaluation will be published in the next issue of Pulsatilla (11).