Ecosystem(contd) emphasis placed on'vertical rather than horizontal relations little value/emphasis given to geographic realisation of the ecosystem Odum in 1970's used concept to study flow of energy; a 'systems' analytical methodology (energy units)Ecosystem (cont’d) emphasis placed on ‘vertical’ rather than ‘horizontal’ relations little value/emphasis given to geographic realisation of the ecosystem Odum in 1970’s used concept to study flow of energy; a ‘systems’ analytical methodology (energy units)