Farmer Tree Planting Barriers to Sustainable Forest Management - Smallholder Tree Growing for Rural Development and Environmental Services - page 413

Patch-scale
tree cover

Landscape-scale solutions for
f ood + fibre + forest functions

natural forest natural forest natural forest

integrated,
multifunctional
landscape: crops, trees,
meadows and forest
patches

Tree plan-
tations

Tree plan-
tations

Tree plan-
tations

intensive
agriculture

intensive
agriculture

intensive
agriculture

Fig. 20.2 Segregate or integrate trees, crops and natural vegetation at patch or landscape scale, to
meet overall needs for food, feed and fibre production, plus environmental service functions (Van
Noordwijk et al. 2001a)

configurations can be ranked on a 'segregate' versus 'integrate' axis, with multi-
functionality of patch-level land cover increasing towards the 'integrate' side.
The term agroforestry has generally been associated with concepts of multifunc-
tionality (at tree, field, farm and/or landscape level), and as such it has transition
zones towards food-crop based agriculture, intensive tree crop production systems,
extensively managed tree plantations and natural forest.
Discussions on 'forest functions' tend to be qualitative (categorical) rather than
based on measurable quantities. The concepts of 'forest' underlying the Kyoto pro-
tocols terminology of deforestation, afforestation and reforestation have been a
major cause of confusion and debate. If the objective is increased storage of carbon
in vegetation and soils, a terminology that is more directly linked to actual C stocks
(and thus in need of more than the two classes 'forest' and 'non-forest') would have
directly qualified 'agroforestry' for carbon credits without much discussion.
Parallel to the Kyoto protocol discussion on 'what is a forest?', the definition used
by FAO in its global forest resource assessment (Box 20.2) is equally arbitrary in
its exclusion of trees planted in the context of agroforestry. Agroforestry research
has since long tried to predict where 'pure crop + pure tree' systems are to be pre-
ferred over mixed ones. Situations where the mixed systems outperform the monoc-
ultures can generally be identified on the basis of complementarity in the use of
labour and other farm-level resources, in the use of space (light capture) and below-
ground resources by differences in root distribution or phenology. Apart from these
farm productivity considerations, however, existing land use classifications do not