A Presentation made by the Ugandan team During the Closing Conference of the Conservation and Sustainable management of the Below Ground Biodiversity Project

1. Land Use and Community composition of Arbusscular Mycorrhizal fungi Mabira
forest ecosystem in Uganda
Mutumba G.Serani S. Okwakol, M .J.N, Lamtoo G. and Kiryose H
Abstract
Arbscular
A b l mycorrhiza fhi fungi i one of th main components of soil microbiota i most ecosystems. Thi group of f
i is f the i t f il i bi t in t t This f fungi i obligate symbionts
i is bli t bi t
colonizing the roots of majority of forest trees and other plants including crop plants. The research hypothesis is that diversity and abundance
mychorrizal fungi in soil is partly affected by the above plant diversity and land use systems. Mabira forest ecosystem has been under intensive
logging and cultivation. Large trees with thick canopy cover have been felled for timber and charcoal burning; and tea / sugar plantations,
seasonal maize, bean gardens have been established thereby altering the balance between below ground diversity and the above ground.
INTRODUCTION
The conservation of Belowground Biodiversity as well as actions to ensure sustainable development in the agricultural and other sectors are now
a scientific imperative. A major feature of global change in the tropics is that of land use associated with agricultural intensification (Lavelle et
al,1997).In
al 1997) In addition to plants soil is the habitat of a diverse array of organisms namely: archaea bacteria fungi protozoans algae and
plants,soil archaea, bacteria, fungi, protozoans,
invertebrate animals, The activities of which contribute to the maintenance and productivity of agroecosystems by their influence on soil fertility
(Hole,1981,Lavelle,1996,Brussard et al 1997). This is mediated through four basic activities: decomposition of organic matter, nutrient cycling,
bioturbation and suppression of soil-borne diseases and pests.
METHODOLOGY
A benchmark site was demarcated into six windows each capturing the major land use types. From each window sixteen soil
samples were collected. A total of ninety six soil samples, 16 in each “window” were collected systematically along regular grid
transects with sampling points spaced 200m apart, using a geographic positioning system (CPS) between November and
December 2004 (techniques as outlined in the methods book were applied) Samples were taken to Makerere University for
applied).
subsequent analysis. Statistical analysis of the data was centrally done.
RESULTS
6
Tea Gras Suga Mixe Fall Fo
Spore abundance as
xe
all
or
ea
5
ga
Six genera, Paraglomus Norton and Redecker, Acaulospora Gerdeman and Trappe,
4
Fall
Entrophosphora Ames and Schneider, Scutellospora Walker and Sanders, Gigaspora s eie r h es
p c s ic n s
For
Gras
Mixe
Suga
3
Gendermann and Trappe (emend. Walker and Sandlers and Glomus Tulasane Tea
Paraglomas Tulasne and Trappe were recorded in all the land use types as illustrate
2
by the accumulation curve (Figure 1)
y ( g ) Figure 1: Arbuscular mycorrhiza genera accumulation curve.
1
Community Composition of AMF
0
All the six AMF genera were present in all land use types studied and Fisher’s Exact test showed 0 5 10 15 20 25 30 35
sites
highly significant (p= 0.0001) generic proportional associations within the land use types.
Generally, Acaulospora accounted for the highest proportion in all LUTS followed by
Scutellospora, then Glomus and the least was Paraglomus (Figure 2). Scutellospora proportion is
stable in all land use types ranging between 24% in forest and 27.2% in sugarcane contrary,
100%
Acaulospora spore numbers vary from 38.1% in sugarcane to 54.7% in grassland. Equally,
80% Para
Paraglomus is almost absent (0.3%) but increases to 2.6% in tea and 2.8% in fallow
Proportion (%)
Entro
respectively. 60% Glom
Six AMF genera Acaulospora, Scutellospora, Glomus, Gigaspora, Entrosphosphora and 40% Giga
Paraglomus were recovered in Mabira Forest and surrounding agricultural land use types. Scutt
20% Acau
Acaulospora and Scutellospora are the dominant genera and Paraglomus the least in the
entire Mabira Forest benchmark site. Similar trends were evident in the various land use 0%
Sugarcane
Fallow
Grassland
Mixed
Tea
Forest
types.
Figure 2: Proportion of Spore types in the land use types.
Scutellospora is more stable suggesting that it is insensitive to environmental change whereas
Acaulospora is sensitive and declines in more disturbed land use types. There is appearance Land Use Types
of Paraglomus to the land use intensification gradient which would be a good indicator of land
degradation.
CONCLUSION
There are trends in mycorrhiza abundance in relation to land use and land use intensification gradients. However more baseline research and replication of sites are
required. In addition the gradient factor and aspect should be investigated because the couple determine water run and soil biota life activities and hence plant
growth and development.
IMPLICATIONS OF THE STUDY
•Dissemination of awareness about BGBD:
•Policy evolution by national governments
•Curriculum changes in syllabi to reflect BGBD
•Continued research at all levels and this type of research should become the new frontier in science because
BGBD affects the immediate human food security
•An implementing agency globally and nationally should be instituted
REFERENCES
1. Hole FD.1981.Effects of animals on soil. Geoderma 25,75-112.
2. Lavelle P, Bignell DE and Lepage M. 1997. Soil function in a changing world :the role of invertebrate ecosystem engineers.European Journal
of Soil Biology 33,159-193.
3. Lavelle P.1996. Diversity of soil fauna and ecosystem function. Biology International 33,3-16.
4. Fatima M. S. Moreira, E. Jeroen Huising and E. Bignell, 2008. A hand book of Tropical Soil biology