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LESSONS LEARNT FOR HARVESTING SEED IN BIODIVERSITY MITIGATION AND ENHANCEMENT SCHEMES IN THE UK. Professor R Neil Humphries CSci CBiol BSc MA PhD MBS MIPSS FIQ Sustainable Reclamation ASMR National Meeting, Tupelo, Ms. June 8th-15th, 2012. Background .
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LESSONS LEARNT FOR HARVESTING SEED IN BIODIVERSITY MITIGATION AND ENHANCEMENT SCHEMES IN THE UK Professor R Neil Humphries CSciCBiol BSc MA PhD MBS MIPSS FIQ Sustainable Reclamation ASMR National Meeting, Tupelo, Ms. June 8th-15th, 2012
Background Objective - to understand more about seed collection from natural sources • Study undertaken in 1992 & 1993 • 5 coalfield grassland – mire/fen meadow sites in South Wales, UK, harvested early & late July • All UK Biodiversity Action Plan grasslands (NVC mesotrophic grasslands MG5 & MG8; mires M23, M24 & M25; acid grassland U5) • Emorsgatetractor-drawn suction harvester • Seed was air-dried, sieved & bagged
Four Studies Undertaken • Donor site species composition and their flower & seed development stages • Species composition of harvested seed • Efficacy of suction harvester • ‘Harvestability’ of seed
M23 Juncuseffusus – Juncusacutiflorus – Galiumpalustre rush pasture
Summary of Results • Number of Key-Constant (+ Rare) Species in Harvested Seed
Lessons Learnt Need for – • Seed-burden surveys • Multiple-harvests • Adequate donor sites • More than one method of collection • Good storage and control of pests
1 – Seed Burden Surveys Year prior to harvest and harvest year: • Determine species composition & field scale spatial variation, access, and • Species flower/seed architecture & seed ripening/shedding period(s), methods of collection • Determine areal contribution to seed yield (area / grasses & forbs) and number of harvests required (single or multiple) • Change land use to maximise seed yield (remove grazing pressure)
2- Multiple Harvests Need for multiple harvests because: • Different seed yields between years (1992 & 1993) • Species ripen at different times within years:
3 - Donor Sites Preplanning - • Access for harvest method • Species composition • Control of land use & management Adequate yield of seed (area) –
4 - More Than One Method More than one seed collection method available More than one because of: • Weather - dry standing crop • Access limitations (steep, patterned & soft ground) • Selective harvest of seed / seed heads (flower architecture, key species, weevil infestation)
5 - Storage & Control of Pests • Seed collected is valuable in terms of effort and limited resource • Reduced viability through infestation by mildews and white-shouldered house moth If not sown on collection there is need for: • Drying & dry storage • Insecticide treatment
Conclusions • Study is highly relevant to today’s drive to establish native plant grassland communities • Study provides basis for planning collection and evidence for achievability to planning authorities • Showed need for careful & informed planning, realistic & achievable programme spanning seed ripening times & a number of years, and sufficient donor resource
AcknowledgementsBritish Coal (former national coal company) for their foresight and funding of this study