Main objective: Identify key components of the soil food web, and their interactions, that confer stability in soil functions following disturbance events
Controls on the stability of soils and their functioning under land use and climate change
Glensaugh
Yorkshire Dales
Devon
Slow fungal channel
Fast bacterial channel
Mobile higher trophic levels
½ N full N
½ tram
full tram
½ tram ½ tram
½ N
½ N
full N
full N
full tram full tram
Drought shelter
Drought shelter
Drought shelter
Drought shelter
Drought shelter
Drought shelter
Unimproved Improved
x 5
Time
Disturbance
Resilience:Magnitude and speed of return to initial state
Resistance:Immediate response to disturbance
• GHG & respiration• Chemistry• Microbial C• PLFA• Root biomass
• Mycorrhiza
• Soil Biology
MEASUREMENTS
@SoilEcolUoM
Air with 13CO2
Pulse labelling
13CO2 released global activity15N2O, 15N2 nitrification / denitrification activity
C and N flow trough the soil food web components : labelling experiment
Follow the fate of added 15N and 13C in the plant-soil system and quantify the impact of drought and management on the C and N flow through soil food web
15NH415NO3
Soil food web
Plant shootPlant rootsMicroorganismsSoil fauna (detritivores, herbivores, predators)
Measurements :
Extensive / intensive managementDrought / control
Closed chamber
Litter
Litter
Litter
13C Labelling experiment
40 µm meshAllow myceliumExclude roots
0.5 µm meshExclude mycelium and roots
Microorganisms Microorganisms+
Detritivores
Microorganisms+
Detritivores+
Predators
Control vs Drought
3 food webs * 2 treatments * 6 rep = 36 mesocosms
+ 6 for natural isotope abundance 42 mesocosms
13C-CO2
Pulse labelling