Rhizosphere Effects of Carboniferous and Clayey Compounds in Sandy Soil Matrices B. U. Schneider 1), K. Boldt 1), A. Rumpel 2), Simone Fritsch 2), K. Baumann 2), R. F. Hüttl 1) 1) German Research Centre for Geosciences GFZ (Helmholtz Centre Potsdam) 2) Brandenburg University of Technology at Cottbus 1
Function of roots and their mycorrhizae in ecosystems Assimilation/ Shoot Growth Nutrient and Water Uptake Carbohydrate Allocation Exsudation,Complexation, Mobilisation Processes Mycorrhizal and Microbial Cenoses Root Growth/Spatial Distribution Turnover 2
Root growth patterns in reclamation forests of the Lusatian post-mining landscape Decreasing pyrite and salt contents Increasing mycorrhizal abundance and diversity Natural forests Reclamation forests Depth of soil amelioration 30-60 cm Proceeding soil development below average rooting depth high root density and mycorrhizal abundance in the top soil layers
Mycorrhizal Vitality in Scots Pine Stands Growing on Naturally Developed and on Reclaimed Mine Spoils (anual mean values, 1994-1997) Meuro Domsdorf Reclamation Forests Neuglobsow Taura Natural Forests Rösa 100% 80% 60% 40% 20% 0% 20% 40% 60% 80% 100% Fully vital vital Limited vitality necrotic dead (Münzenberger et al. 2004)
Spatial distribution of fine roots (Ø < 2mm) in a 20-year old Pinus nigra stand on reclamation sites Tree positions - 16 cm - 36 cm - 56 cm - 83 cm - 110 cm Root dry mass [g 100 cm - ³] 0,000-0,001 0,002-0,099 0,100-0,149 0,150-0,249 0,250-0,449 0,450-0,649 0,650-1,499 1,500-4,649
3D Sampling campaigne Approaching soil heterogeneity High resolution 3D-sampling of a soil monolith in a Pinus nigra reclamation forest
Rhizotron experiments on root proliferation into lignite compounds in a sandy soil matrix Lignite fragments in a sandy soil matrix with lignite fragments without lignite fragments Distance to lignite fragments: Region A >2 cm Region B 2-1 cm Region C 1-0 cm Region D lignite fragments
Rhizotron experiments on root proliferation into lignite compounds in a sandy soil matrix Seedlings survived enhanced drought only if lignite compounds were present The ratio of vital mycorrhizal root tips was significantly higher for treatments with lignite compounds Ratio Prozent of Wurzelspitzen root tips (%) 100 90 80 70 60 50 40 30 20 10 0 with mit Mykorrhiza mycorrhiza without ohne Mykorrhiza mycorrhiza tot dead lebend living Ratio of living and necrotic root tips for mycorrhizal and non-mycorrhizal seedlings for treatments with lignite fragments
Rhizotron experiments on root proliferation into lignite compounds in a sandy soil matrix Preferential root proliferation of Pinus sylvestris fine roots into lignite compounds is resulting in: Increased nutrient adsorption Higher water availability Mycorrhiza enhancement Improved growth performance
The influence of heterogeneity derived from clay fragments in a sandy soil matrix Colonization of lignite fragments by roots and mycorrhizal hyphae Penetration of lignite fragments without initial fungal inoculation after being exposed to mycorrhizal roots of Scots pine seedlings for three months [Magnification: a) 1 : 1.000, b) 1 : 2.500, c) 1 : 25.000, d) 1 : 60.000]
The initial stage of ecosystem development: The artificial water catchment Chicken Creek Abbau-/Rekultivierungsbereich
The artificial water catchment Chicken Creek - construction phase Cross-section A-B (schematic, not to scale) A B Sand (quartär) (2-3 m) Basisschüttung Ton (1-2 m) A Sand Clay B Luftbild Juni 2007
The artificial water catchment Chicken Creek - construction phase 450 m 60 m 6 ha surface area 130 m 15 m Luftbild Juni 2007
The influence of heterogeneity derived from clay fragments in a sandy soil matrix Fragments vs. Sandy soil matrix Fragment Volume: 21 cm³ 285 cm³ Bulk density of Fragments: 1.7 2.1 g/cm³ from: Boldt-Burisch et al. (2012) Plant Soil C. epigeios L. corniculatus L. corniculatus 15
The influence of heterogeneity derived from clay fragments in a sandy soil matrix Grain size distribution in Vol.-% Particle size (mm) 0,002 Clay Silt Sand 0,002-0,0063 0,0063-0,02 0,02-0,063 0,063-0,2 0,2-0,63 0,63-2,0 Fragments 14,6a 7,4 12,8 12,2a 27,0 17,5a 2,6a Sandy matrix 1,9b / / 2,0b 31,7 56,3b 7,6b 16
The influence of heterogeneity derived from clay fragments in a sandy soil matrix Water Soluble Nutrients Nutrients H2O (mg cm -3 ) Ca H2O K H2O Mg H2O Mn H2O P H2O Zn H2O Sandy Matrix Mean value 0.049 a 0.016 a 0.010 a 0.0004 a 0.0012 a 0.0002 a Standard Dev. 0.007 0.009 0.005 0.0003 0.0006 0.0001 Fragments Mean value 0.097 b 0.023 a 0.019 b 0.0004 a 0.0015 a 0.0002 a Standard Dev. 0.022 0.012 0.010 0.0003 0.0009 0.0001 17
The influence of heterogeneity derived from clay fragments in a sandy soil matrix Total root nutrient contents Total nutrient contents (mg g -1 ) Roots that grew in the sandy substrate Root that grew in the fragments Ca 12,5 ± 2,0 a 13,7 ± 6,8 a Fe 4,5 ± 1,3 a 5,1 ± 2,1 a K 2,8 ± 1,3 a 7,4 ± 5,7 b Mg 1,7 ± 0,4 a 4,5 ± 3,1 b Mn 0,2 ± 0,03 a 0,4 ± 0,2 b P 0,6 ± 0,1 a 0,7 ± 0,2 a Zn 0,03 ± 0,007 a 0,03 ± 0,01 a 18
The influence of heterogeneity derived from clay fragments in a sandy soil matrix Soil Water Content (g g -1 ) (Juli) Sandy matrix Fragments Mean: 0.036 a SD: 0.003 Mean: 0.134 b SD: 0.031 n = 8 19
The influence of heterogeneity derived from clay fragments in a sandy soil matrix Experimental Verification: Effect of carboniferous fragments in a sandy soil matrix on root growth patterns of L. corniculatus and C. epigeios. 2 cm Experimental design: Variant L. corniculatus C. epigeios 40 cm Control Only N-Spots x x x Only P-Spots x 20 cm Rhizotron experiment with randomly distributed carboniferous fragments in a sandy soil matrix. N- and P-Spots diagonally alternating (n = 5) x Sandy substrate (sieved, Ø 2 mm) were taken from the experimental sites of the Chicken Creek project area x 20
The influence of heterogeneity derived from clay fragments in a sandy soil matrix L. corniculatus C. epigeios 21
The influence of heterogeneity derived from clay fragments in a sandy soil matrix 3.0 L. corniculatus 3.0 Shoot C. epigeios Root 2.5 2.5 Biomass (g) 2.0 1.5 1.0 Biomass (g) 2.0 1.5 1.0 0.5 0.5 0.0 Control N+P- Spots 0.0 Control N- Spots P- Spots N+P- Spots 22
Spatial and Seasonal Distribution of Root Surface Area [cm²] Based on Minirhizotron Observations 60cm x 60cm x 200cm 13mm 18mm L. corniculatus C. epigeios 10 Root surface [cm² 1000cm - ³] 40 70 110 140 200 Sept. 08 May 09 July 09 Sept. 09 soil depth [cm] Sept. 08 May 09 July 09 Sept. 09 0-3 4-24 25-49 50-99 100-149 150-249 250-349 350-449 450-549 550-650
Vertical distribution of root tips for monoculture Scots pine (K 84) and Beech (B 91) Scots pine - 84 Beech - 91 Aeh Aeh Bv Bv Bv lcv lcv II lcv 0 cm 100 Ah Ah Bv Bv lcv II lcv 0 cm 100 Legend for geological layers gk mk fk III lcv gs III lcv IV lcv 200 IV lcv 200 ms fs V lcv U VI lcv 300 V lcv 300 T VII lcv 400 0 5 10 15 20 % VI lcv 400 High bulk density
Seasonal Dynamic of Root Tip Formation Seasonal increment of root tips (%) 1800,0 1600,0 1400,0 1200,0 1000,0 800,0 600,0 400,0 200,0 0,0 Scots pine age 84 0-1m 1-2m 2-3m 3-4m Date of Observation Reference point: Numbr of root tips in March 2002
Seasonal Dynamic of Root Tip Formation Seasonal increment of root tips (%) 4000 3500 3000 2500 2000 1500 1000 500 0 0-1m 1-2m 2-3m 3-4m Beech age 91 04.06.02 25.06.02 22.07.02 07.08.02 26.08.02 24.09.02 16.10.02 06.11.02 Date of Observation Reference point: Numbr of root tips in March 2002
Conclusions Lignite compounds as well as clayey soil aggregates and layers in sandy soil matrices may significantly improve the water and nutrient uptake of plants. These compounds clearly account for a spatially heterogeneous distribution of fine roots. Access to water and nutrients is rather provided through mycorrhizal hyphae than by roots, in particular, with regard to phosphorus. Future research should focus on the longevity and the physical stability of such structures, i.e. through the combination of mineral and organic compounds (optimum design) and their impact on the biogeochemical cycles particularly considering hydrophobicity effects Transfer of related technologies into the market requires a comprehensive assessment of the economic revenue and of the CO 2 footprint involved.
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