TROPICS Tropical Forestry Projects Information System

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 Regional: Global/Cross Regional

The selection of fast growing trees for sustainable production in the semi-arid zone.
Figures are indicative, and subject to revision
Some projects may contain substantial non-forest related components
Funder reference :ERBTS3* CT930232
Funded through :Science
DGXII
STD-III
Year :1994
Engaged :500,000 Euro
Further information :DGXII Published Information
Information in the TROPICS system is provisional only
Comments and suggestions to tropics@odi.org.uk
 

STD3-95
 DGXII Published Information
Funded joint research projects - 1995 edition

Contract Number ERBTS3*CT930232

 

THE SELECTION OF FAST GROWING TREES FOR

SUSTAINABLE PRODUCTION IN THE SEMI-ARID ZONE :

N2 FIXATION AND MICROBIOLOGY, SOIL AMELIORATION,

WHOLE PLANT PHYSIOLOGY, GENETICS, WATER AND NUTRIENT USE

Objectives

The main objectives are as follows :

F
To identify tree species which are capable of fast growth and amelioration of degraded soils with minimal use of plant nutrients and water in the semi-arid zone.

F
To compare root distributions of arid-zone tree species vis-a-vis their likely competitive effects on crop plants when used in simultaneous agroforestry systems.

F
To characterise strains and species of Rhizobium using molecular biological techniques and assess, a) their capacity to withstand environmental stress, b) their ability to stimulate tree growth, c) their persistence in the field following outplanting, and d) the possibility of identifying molecular markers for fast growth.

F
To define the mycorrhizal inoculation requirements for semi-arid zone tree species, and assess the capacity of mycorrhizas to stimulate tree growth.

F
To assess the effects of varying photon flux density on photosynthesis in semi-arid zone tree species and its influence on N2 fixation and water use efficiency.

Activities

The key activities envisaged are :

*
Destructive biomass sampling systems to estimate tree growth and nutrient use. Neutron probe and sap flow technologies will be employed to obtain comparative water use data. Soil nutrients, root, Rhizobium and mycorrhizal distributions will be assessed by systematic soil coring and litter inputs by littertrap and litter bag decomposition techniques.

*
Characterisation of bacterial strains by, PCR, RFLP and RAPD, stress tolerance of strains will be assessed under controlled conditions in the laboratory, the effects of varying light on N2 fixation and water use efficiency will be assessed by porometry, d15N and d13C in controlled conditions.

*
Tree growth stimulation by microsymbionts will be assessed by inoculation of nursery stock and subsequent outplanting. Comparative growth stimulation by native and exotic Rhizobial strains will be assessed after outplanting in the field. Molecular methods will be utilised to assess whether inoculated strains of Rhizobium persist on seedlings after transplanting.

Expected Outcome

The work carried out in this project should provide guidance for tree species selection for the semi-arid zone. It should identify tree species which are capable of fast growth and soil amelioration as well as those which have root distributions which are likely to be less competitive with crop plants in simultaneous agroforestry systems. The programme should also highlight useful microsymbiont strains and improve the ability to taxonomically distinguish them. Information on the necessity and effects of microsymbiont inoculation programmes for semi-arid zone forestry species should be improved.

Information in the TROPICS system is provisional only
Comments and suggestions to tropics@odi.org.uk