Grassland Management Graham Bellamy
How did grassland originate? In Britain the last ice age finishing 10k years ago started the modern vegetation clock
Grassland in the countryside
soils
Soil type is dependant on geology Calcareous soils – (Chalk/Limestone ..lime plentiful) Acid soils (low lime ..often sandy). Neutral soils (some lime often on clay) pH 5-7 … all can be wet or dry
Improved grassland has been improved for agricultural production by the addition of fertiliser, re-sown with grasses, and /or subject to herbicide use to reduce non grass plants Unimproved grassland will have had no extra fertiliser or herbicide and most wildflowers. Semi-improved grassland can be similar to unimproved but will have had some addition of fertiliser or some intensive management
Three main types of grassland at Chorleywood Common Calcareous (chalk ) Grassland Acid Grassland Neutral Grassland
Find out what plants grow and what other wildlife lives in the grassland Is there anything important? Where to get your information from? Ask your local Wildlife Trust. Is there a Natural History Society and talk to the recorder for plants..there may be a recent plant atlas. There may be a biological records centre for your county
Small Tortoiseshell 15/08/1997 11/07/2004 01/01/2003- Orange-tip 23/04/2003 14/04/2007 31/12/2003- Ringlet 2003 01/01/2003 Holly Blue 2002 14/07/2007 Small Heath 03/06/2006 03/06/2006 Brimstone 04/06/2004 14/04/2007 01/01/2003- Peacock 23/04/2003 25/04/2008 Small Copper 15/08/1997 27/08/2007 Meadow Brown 30/07/1997 27/08/2007 Marbled White 2002 13/07/2004 Purple Hairstreak 27/08/2007 27/08/2007 Large Skipper 2003 30/07/2004 Speckled Wood 30/07/1997 27/08/2007 Large White 30/07/1997 27/08/2007 Green-veined White 30/07/1997 03/06/2006 Small White 15/08/1997 27/08/2007 Comma 2003 14/04/2007 Common Blue 30/07/1997 03/06/2006 Hedge Brown 30/07/1997 27/08/2007 White-letter Hairstreak 13/07/2004 13/07/2004 Essex Skipper 15/08/1997 15/08/1997 31/12/2003- Small Skipper 2003 01/01/2003 Red Admiral 2002 27/08/2007 Painted Lady 2003 03/06/2006
Hertfordshire Biodiversity Action Plan (BAP) Source of information on wildlife habitats in Herts. Major habitats have a Habitat Action plan (HAP) All counties will have a BAP you can find information online
County flora`s will have much plant information..2009 and 1967 for Herts.
Unimproved Grasslands..most wildlife 95% plus lost nationally in last century 950Ha unimproved neutral grassland left in Herts..10.5 ha on Chorleywood Common
Neutral Grassland Old hay meadows and pastures:- hay cut in late June to July or managed by grazing Low soil nutrients keep competitive grasses in check allowing finer grasses and broad leaved herbs to flourish. The regular cutting favours a community of plants seeding before the hay cut. Addition of fertiliser promotes dominance of tall grasses and loss of other plants .= bad!
Typical herb species of unimproved Neutral Grassland… Birds-foot Trefoil, Black Knapweed, Red Clover, Meadow Buttercup, Ox- eye Daisy, Lady's Bedstraw, Yellow Rattle, Violets and Cowslip. Grasses include Red Fescue, Sweet Vernal Grass, Crested Dogs-tail and Common Bent
Yellow rattle
Cow slip
Ox-eye Daisy
Acid Grassland and Heathland Chorleywood Common is a key Heathland site in Herts. (BAP) Only 145 ha acid grassland and 21 ha heathland left in Herts…10.5 and 0.3 on common respectively
Typical acid grassland plants Fine leaved fescues and bent grasses, wavy hair grass. Sheep's Sorrel, Sorrel. Heath Bedstraw, Heather, Gorse.
Sheep`s Sorrel
Calcareous or Chalk Grassland 178 ha left in Herts. 1.5 ha on common
Barton hills NNR ancient chalk dow nland
Pasque flow er
Main threats to Unimproved Grassland today:-
Fragmentation of habitat:- small isolated sites likely to lose species….increase connectivity and make sites larger. Lack of grazing or cutting leading to growth of scrub and woodland . Over- grazing and other intensive management using fertiliser and herbicides Climate change…..loss of species….new species. Nutrient enrichment. Problems of grazing public sites:- people …dogs.
The principal nutrients that plants require are nitrogen (N), phosphorous (P), potash (K) and sulphur (S) Where does this come from? Pollution…. Fertiliser… This has effects on grassland of nature conservation importance that are nutrient poor
Many grasslands have recent signs of nutrient enrichment… This leads to coarse growth
Enriched grassland at edge of path used by dog walkers
Good wet grassland
Enriched wet grassland
If you have important wildlife grassland a Management Plan will help to pull information together..
How are grasslands managed? Mowing Grazing Sometimes burning
Burning…destructive in summer for invertebrates and other animals
Mowing …. generally vegetation cut to a uniform height, reducing habitat variety at a stroke! Can lead to overall reduction in diversity of plants and invertebrates Traditional hay meadows – cut at the same time every year to allow seeding are often very rich in plants All cuttings should be removed to stop soil becoming too rich Timing of cut is important depending on the site … September cut increases species richness on nutrient poor sites but an earlier cut (eg July) is more effective on more productive sites as it controls competition from more aggressive grasses .
Grazing … Most grasslands have developed with grazing management Slow removal of vegetation..no sudden change as with mowing Livestock graze selectively and produce an uneven tussocky sward that provides a range of habitats..unless overgrazed Regeneration niches..new seed beds.. are created for grassland plants by the trampling of livestock Timing and stocking density very important to prevent overgrazing and poaching
Cattle – More tolerant of wet conditions than sheep Relatively unselective in grazing behaviour, not concentrating on flower heads, and good for removing long or rank vegetation and controlling invading scrub Particularly suited to sites requiring summer grazing as they do not graze flowers preferentially
Suckler herd
Traditional breeds more suited to unimproved grasslands
Sheep and Horses … Sheep graze closely and evenly producing a more uniform sward. Horses are particularly good at opening up rank vegetation but overgrazing needs to be closely monitored..have latrine areas that become long
Exmoor ponies..hardy..dartmoor and konics Also used
Hebridean sheep pegsdon hills
It can all go wrong….
Over-grazing and poaching… leads to w eeds..low biodiversity
Winter feeding…stock outdoors…lack of indoor facilities
Creeping thistle
It reverts to scrub once its gone its lost…
Scrub invaded grassland…cottage bottom
Undergrazing w ith bramble development.. w hen graze to control?
Invertebrates What is there..what is past history Maintain structural diversity in the vegetation..not cut all at once..value bare ground south facing banks Pollen and nectar sources No avermectin wormers for livestock ( several weeks)…no slow release wormers Cutting ..no dung fauna..mow to produce cut and uncut patches..tartan! Remove mowings.
Large skipper
Some scrub is good
Grassland and scrub edge
Dingy skipper
Monitor..record how the special things are doing
Lowland Grassland Management Handbook http://jncc.defra.gov.uk/page-5852 http://www.grasslands-trust.org/types-grassland- habitat http://www.wildlifetrusts.org/wildlife/habitats/gras sland http://www.buglife.org.uk/conservation/adviceon managingbaphabitats/lowlanddryacidgrassland
Habitat creation
Can be large scale!! ..or even small can be good
Smaller still
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