Lessons learned from Grassland Management in Bavaria

Transcription

1 Lessons learned from Grassland Management in Bavaria Dr. Matthias Dolek

2 Landscape Management Concept Landschaftspflegekonzept (LPK) Published by ANL in 20 Volumes Summarizes information on important habitats and their conservation E.g. calcareous grasslands, ponds, dams, dikes, and railway lines Here: Summary on grassland habitats Plus: additional information

3 photos: left: Landschaftpflegekonzept, right: source: LPK Buckelwiesen ( humpy meadows ) Typical habitat of alpine region, restricted to valleys, where ice age glaciers were and strong föhn winds occur Modelled by glaciers and especially by following frost and karst processes Calcareous grassland, small scale mix with plant species of acidic soils and fens

4 source: Tagfalter in Bayern (2013) Buckelwiesen ( humpy meadows ) Argynnis niobe, Melitaea aurelia, Polyommatus dorylas

5 photo: source LPK Wiesmahdhänge mown grassland on slopes Habitat similar to humpy meadows More or less steep slopes Calcareous grassland with fen species in wet parts Comparison of traditional mowing and grazing

6 species number Butterfly Transects on calcareous grassland slopes (Wiesmahdhänge) grazed mown abandoned transect length (m) Similar results for species composition and rare species, but consider single species and grazing intensity source: Dolek & Geyer 1997

7 source: Dolek & Geyer 1997 Example Carcharodus flocciferus comparison of egg-density of one grazed, one early mown (before flight period) and one late mown (after flight period) site summer mowing could be a key factor for the unusually high density of C. flocciferus on the studied meadows Egg density (mean ±SE) of C. flocciferus Numbers indicate n of each group (Mann-Whitney U-tests: early mown grazed (***) U56.5, p,0.1%; early mown late mown (***) U58.5, p,0.1%).

8 Management Recommendations humpy meadows and steep slopes Date of mowing extremely relevant In general between 15. July and 15. August Keep low cover of grasses of fallows (<20%) and tall herbs, Trifolio-Geranietea (<10%) Controlled fallow (10-30%, 3 years, 2y mown). Fringes mown every 3-5y, parts mown in autumn On humid sites with Molinion species mowing 1 month later On sites with eutrophication mowing before 15. July Consider extremely rare species & phenology Dry the cut material on site source: LPK

9 photo: Tagfalter in Bayern (2013) Structural diversity on wet meadows and litter meadows Standard procedure: mowing in summer or autumn Examples Lycaena helle and Boloria eunomia Both species inhabit short-time fallows of wet meadows and litter meadows L. helle usually in forest vicinity and forest gaps Required features: Short-time abandoned grasslands Larval food-plant Bistorta officinalis abundant L. helle possibly single shrubs and trees as wind protection Management: Mowing only sectoral and only in autumn Rotational Management of wet meadows, maintaining different successional stages Depending on productivity, long-time fallows are suboptimal Rare example: extensive cattle grazing

10 photos: Structural Diversity on alpine pastures Parnassius apollo und Maculinea arion breeding habitats Larval food-plants Sedum album (P. apollo) and Thymus sp. (M. arion) Both occur regularly on rocks and heaps of stones on the pastures Loss of habitats by small changes Removal of rocks and heaps of stones Manure applied across rocks within pastures by improved access Keep structural diversity, even of superficially unimportant features

11 photo: Tagfalter in Bayern (2013) Structural Diversity on alpine pastures Example Polyommatus dorylas Typical habitats: south-exposed steep slopes Extremely steep, thus little grazed by cattle Low-growing calcareous grassland Open soil by cattle trampling and slides where the larval food-plant Anthyllis vulneraria grows Maintaining habitats with open nutrient-poor soil by: Extensive grazing in steep slopes Mechanical management: Removal of top soil layer

12 Forest-Grassland-Ecotones Lopinga achine Forest with low cover of about 40%, slightly humid, dense grass layer, nutrientpoor Dependant on dynamic processes, such as difficult edaphic and topographic conditions, wildungulates, grazing cattle Grazing intensity has to maintain open structure and dense grass layer Argynnis niobe Nutrient-poor, xeric or slightly humid grasslands in forest gaps or in vicinity to forests Large area needed Extensive cattle grazing or summer mowing (one cut) are possible

13 Tree density light dense Forest grazing conflicts of interest Protective forest Forest grazing None / low Grazing intensity high Fotos: (links), (rechts); Königer et al

14 Tree density Forest grazing conflicts of interest light dense Forestry -Productivity -re-growth, young trees -protective function Conservation -natural -half-open landscape -habitat mosaic Mountain Farmers -summer pasture -nutrient-rich feeding -health of livestock -Quality of meat/milk None / low Grazing intensity high

15 Forest grazing ecological features parameter pasture grazed forest ungrazed forest Protection against avalanches Water holding function biodiversity Rare species

16 Grazed forest as habitat of endangered species black grouse ( Boloria euphrosyne Vipera berus ( Lopinga achine

17 Conclusions LPK may serve as a model to summarize management information Habitat types do not always cover zoologically important features Heterogenity of land-use is always important Traditional land-use is a good baseline New impacts (e.g. nutrient input) have to be considered additionally Do not forget mixed habitats and short-time fallow land

18 Thank you for your attention!

19 source: Tagfalter in Bayern (2013) Lebensraum Fluss-Schotterflur (Tagfalteratlas) Polyommatus bellargus, Spialia sertorius, Boloria thore, Maculinea arion, Lasiommata petropolitana

20 Verzahnung von Bergwald, Vorwaldstadien, Magerrasen und Fels- und Schuttfluren source: Tagfalter in Bayern (2013) Erebia oeme, Lasiommata petropolitana, Melitaea phoebe, Pyrgus andromedae, Parnassius mnemosyne

21 source: Tagfalter in Bayern (2013) Lebensraum Bergwald (Tagfalteratlas) Boloria euphrosyne, Lasiommata maera, Nymphalis antiopa, Euphydryas aurinia

22 Lichtungsreiche, weidegeprägte Schneeheide- Kiefernwälder Fotos: links/mitte: rechts: Landschaftspflegekonzept Vorkommen: Alpentalräume und Alpenvorland Kennzeichnend ist eine innige Durchdringung und räumliche Verzahnung floristisch und strukturell sehr heterogener Vegetationsformationen. Hervorgerufen wird diese Heterogenität durch einen kleinräumig oft scharfen Wechsel der Relief- und Substrateigenschaften.