Emma-Lee Glen PhD student (3 rd year) Department of Environmental and Geographical Sciences Manchester Metropolitan University, UK
What causes problems for ecological restoration on ex-arable land? 1. Impoverished seed bank 2. Limited natural colonisation 3. Nutrient rich soil (4. Others )
A novel solution: topsoil inversion? Novel technique in ecological restoration Project developed from Landlife s work on topsoil stripping Uses imported Danish deep plough Results in burial of topsoil below layer of subsoil
0-10 10-20 20-30 30-40 40-50 50-60 60-70 70-80 10-20 0-10 20-30 30-40 40-50 50-60 60-70 70-80 60-70 50-60 40-50 30-40 20-30 10-20 0-10 70-80 Unploughed Conventionally Deep ploughed ploughed
A novel technique for addressing ecological Aim of PhD to assess the effectiveness of topsoil inversion in facilitating the creation or restoration of native habitats on ex-arable land Methods
How does topsoil inversion affect the soil profile? Comparison immediately after ploughing: Mean +/- SE (N = 4) conventionally ploughed deep ploughed 1 2 3 depth (10 cm sections) 1 2 3 4 5 6 7 8 1 2 3 carbon content (% loss on ignition) *** ** *** *
How does topsoil inversion affect the soil profile? Comparison immediately after ploughing: Mean +/- SE (N = 4) conventionally ploughed deep ploughed 0.0 0.2 0.4 0.6 0.8 1.0 1 *** depth (10 cm sections) 2 3 4 5 6 7 *** ** * * 8 0.0 0.2 0.4 0.6 0.8 1.0 total N (mg/kg)
How does topsoil inversion affect the soil profile? Changes over time: Before ploughing Total N (mg/kg) 1.600 1.400 1.200 1.000 0.800 0.600 0.400 0.200 0.000 Surface (0-10 cm) total N (mg/kg) Conventionally ploughed Deep ploughed 1/8/04 17/2/05 5/9/05 24/3/06 10/10/06 28/4/07 Date Mean +/- SE (N=4)
How does topsoil inversion affect nitrogen leaching? Ammonium Ammonium (mg/l) 0.6 0.4 0.2 0.0 2 Feb 06 24 Mar 06 13 May 06 2 Jul 06 21 Aug 06 10 Oct 06 29 Nov 06 18 Jan 07 9 Mar 07 28 Apr 07 17 Jun 07 Control Conventional Deep Plough Nitrate N it ra t e ( m g / L ) 30 20 10 0 2 Feb 06 2 4 M ar 06 13 M ay 06 2 Jul 06 21 Aug 06 10 Oct 06 29 Nov 06 18 Jan 07 9 M ar 07 28 Apr 0 7 17 Jun 07 Control Conventi onal Deep Plough
How does topsoil inversion affect the seed bank? Depth (10 cm sections) 1 2 3 4 5 6 7 8 ** ** * * 0 100 200 300 400 number of seeds per litre Conventionally ploughed Deep ploughed
What are the implications for plant community development? 1. Effect on vegetation cover Conventionally 90 140 ploughed 80 % bare ground 70 60 50 40 30 20 10 0 % cover 120 P<0.001 100 P<0.01 80 60 40 % bare ground Total % vegetation cover Deep ploughed P<0.05 P<0.001 P<0.05 20 DP 0 CP DP CP DP CP YEAR1 DP CP YEAR2 DP CP YEAR3 DP CP YEAR1 YEAR2 YEAR3
What are the implications for plant community development? 2. Effect on plant diversity 2.5 Plant diversity (mean +/- 1 SE) Shannon-Weiner H 2.0 1.5 1.0 0.5 P<0.05 P<0.05 0.0 DP CP YEAR1 DP CP YEAR2 DP CP YEAR3
Conclusions 1. Topsoil inversion reduces surface nutrient levels immediately after ploughing, and the effect lasts at least 3 years. 2. Inverted soil leaches more nitrate in the first autumn after ploughing than conventionally ploughed soil. 3. Topsoil inversion buries the seed bank to depths sufficient to prevent germination, reducing the effects of weed competition with introduced plant species. 4. Plant species diversity is significantly higher in inverted soil three years after ploughing. Topsoil inversion has potential for improving the success of ecological restoration on ex-arable land.
Thank you Liz Price Simon Caporn Jacky Carroll Phil Wheater Laurence Jones Bridget Emmett Richard Scott Damian Young Grant Luscombe