4. Habitat provision by trees
•
•
•
•
•
•
Microclimate buffering
Nutrient availability
Water availability
Provision of C substrates
Host for pollinators
Host biological control agents
5. Habitat provision by trees
Pres. #4,#5,#6
Pres. #1,#2,#3
TREE-BGBD
WaNuLCAS
TREE-AGBD
6. Tree-soil interactions and
the provision of soil-mediated
ecosystem services
Edmundo Barrios, Fred Ayuke, Diana H. Wall, Scott Bates,
Noah Fierer, Keith Shepherd
University of Nairobi
GSBI
Global Soil Biodiversity Initiative
11. What about trees and
soil-based ecosystem services?
Strong linkage between aboveground biodiversity
(vegetation/crops) and belowground biodiversity
(soil organisms)
Great potential to strategically utilize land use and
management systems to influence
the provision of ecosystem goods and services
13. Some effects of trees are mediated through
impact on soil biota – trees increase abundance
Mean density of different soil biota and calculated response ratios
Agroforestry
Soil macrofauna
Earthworms
Beetles
Centipedes
Termites
Ants
Soil mesofauna
Collembola
Mites
Soil microfauna
Non-parasitic nematodes
Parasitic nematodes
Agriculture
RR
References
(indiv m-2)
54.4
20.9
2.7
90.7
23.2
(indiv m-2)
17.6
9.6
0.5
81.0
8.6
3.1
2.2
5.6
1.1
2.7
1,2,3,4,5,6
1,2,5
1,2,5
1,2,5
1,2,5
(indiv m-2)
3890.1
5100.7
(indiv m-2)
2000.7
1860.1
1.9
2.7
7
7
(indiv liter-1)
2922
203.7
(indiv liter-1)
1288
211.5
2.3
1
8
8
Barrios et al. 2012
14. Some effects of trees are mediated through
impact on soil biota – trees increase activity
Greater soil biological activity (earthworms) near trees
but effect greater for some tree species than others
Pruned trees
Free growing trees
Earthworm cast weight
Sample with no
earthworm casts
Pauli et al 2010
15. TREES AS HOTSPOTS OF BIOLOGICAL ACTIVITY
IN AGRICULTURAL LANDSCAPES
Barrios et al. 2012
16. Land Health Surveillance
AfSIS - A Globally Integrated African Soil
Information Service (www.africasoils.net)
International Center for Tropical Agriculture (CIAT) Tropical
Soil Biology and Fertility Institute (TSBF), Earth Institute at
Columbia University, World Agroforestry Centre
(ICRAF), International Soil Reference Information Centre
(ISRIC)
With support from Bill & Melinda Gates Foundation and
Alliance for a Green Revolution in Africa (AGRA)
17. AfSIS Sentinel Sites
10 km
Cluster#4
Cluster#8
Cluster#12
Cluster#16
Cluster#3
Cluster#7
Cluster#11
Cluster#15
10 km
Cluster#2
Cluster#6
Cluster#10
Cluster#14
Cluster#1
Cluster#5
Cluster#9
Cluster#13
SENTINEL SITE (100 km2)
21. LDSF characterization of Woody Cover
PLANTS
T-square method
Tree density, basal area, biovolume and biomass
22. Tree Density Mapping at Fine Resolution
Map of tree density in an areas with steep climatic gradients in northern Kenya, derived
from modeling ground data collected from sentinel sites to Landsat imagery (28.5 m
resolution).
25. Soil Biological Properties
Soil samples
0-20 cm, 20-50 cm
Composited per plot (1000 m2)
Soil monoliths
One per subplot (100 m2)
Soil analysis
Soil DNA analysis (dry soil)
Soil macrofauna
25 cm
Soil DNA analysis (DESS soil)
20 cm
Soil analysis
Systematic assessment of Local Ecological Knowledge on tree-soil biota interactions
Barrios et al., 2013
27. Pyrosequencing
DNA extracted from soil samples
-High throughput system
-PCR amplification with group
specific primers for SSU rRNA gene
-Pyrosequencing gives ~1500 sequence
per sample across many samples
(>450,000 seq per run)
- Illumina (MySeq 5 million seqs per run)
-Taxonomic Information
per sample
AGCCTTAA…
AGCCTTAA…
AGCCTTAA…
GCTACCAT…
GCTACCAT…
GCTACCAT…
CGGATCAC…
CGGATCAC…
CGGATCAC…
CTCGATTC…
CTCGATTC…
CTCGATTC…
28. Soil total N
Bradyrhizobium DNA sequences
Heat map showing the levels of total % N in soil (left) as well as abundance of DNA sequence
types representing Bradyrhizobium (right) at Sentinel Site
29. CHALLENGES & OPPORTUNITIES
Developing better understanding of
AGBD/BGBD interactions
Recommendations of what types of tree
densities, arrangements and species
maintain essential ecosystem functions
provided by soil biota
in agricultural landscapes.
30. Identifying, Quantifying and Mapping
Host Spots of Biological Activity and
Ecosystem Services
Temporal and spatial dynamics as a
result of environmental factors in situ
Predictive knowledge of
Ecosystem Service Provision
31. Developing Local Soil Health
Monitoring Systems to evaluate
Ecosystem Service provision
performance
Allow rural communities,
environmental/agricultural institutions
and local government
Prepare for negotiations related to
Payment for Ecosystem Services
Essentially what this technique allows us to do is to analyze many hundreds of samples simultaneously with the community in each sample (bacterial or eukaryotic) analyzed in depth. We typically end up with more than 1500 sequences per sample. of the ssu rRNA gene with each sample receiving a unique 12 bp error-correcting barcode of the ssu rRNA gene with each sample receiving a unique 12 bp error-correcting barcodeDescription of barcoded pyrosequencing. 16s for bacteriaSequences belonging to each sample identified using the barcodesof the ssu rRNA gene with each sample receiving a unique 12 bp error-correcting barcode