A novel technique for addressing ecological restoration constraints on ex-arable land

Transcription

1 Emma-Lee Glen PhD student (3 rd year) Department of Environmental and Geographical Sciences Manchester Metropolitan University, UK

2 What causes problems for ecological restoration on ex-arable land? 1. Impoverished seed bank 2. Limited natural colonisation 3. Nutrient rich soil (4. Others )

3 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

4 Unploughed Conventionally Deep ploughed ploughed

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6 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

7 How does topsoil inversion affect the soil profile? Comparison immediately after ploughing: Mean +/- SE (N = 4) conventionally ploughed deep ploughed depth (10 cm sections) carbon content (% loss on ignition) *** ** *** *

8 How does topsoil inversion affect the soil profile? Comparison immediately after ploughing: Mean +/- SE (N = 4) conventionally ploughed deep ploughed *** depth (10 cm sections) *** ** * * total N (mg/kg)

9 How does topsoil inversion affect the soil profile? Changes over time: Before ploughing Total N (mg/kg) 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)

10 How does topsoil inversion affect nitrogen leaching? Ammonium Ammonium (mg/l) Feb Mar May 06 2 Jul Aug Oct Nov Jan 07 9 Mar Apr Jun 07 Control Conventional Deep Plough Nitrate N it ra t e ( m g / L ) Feb M ar M ay 06 2 Jul Aug Oct Nov Jan 07 9 M ar Apr Jun 07 Control Conventi onal Deep Plough

11 How does topsoil inversion affect the seed bank? Depth (10 cm sections) ** ** * * number of seeds per litre Conventionally ploughed Deep ploughed

12 What are the implications for plant community development? 1. Effect on vegetation cover Conventionally ploughed 80 % bare ground % cover 120 P< P< % bare ground Total % vegetation cover Deep ploughed P<0.05 P<0.001 P< DP 0 CP DP CP DP CP YEAR1 DP CP YEAR2 DP CP YEAR3 DP CP YEAR1 YEAR2 YEAR3

13 What are the implications for plant community development? 2. Effect on plant diversity 2.5 Plant diversity (mean +/- 1 SE) Shannon-Weiner H P<0.05 P< DP CP YEAR1 DP CP YEAR2 DP CP YEAR3

14 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.

15 Thank you Liz Price Simon Caporn Jacky Carroll Phil Wheater Laurence Jones Bridget Emmett Richard Scott Damian Young Grant Luscombe