[Tagging] Feature Proposal - RFC - leaf_type and leaf_cycle

[Rudolf Martin]

Hi all,

there are several tags to indicate vegetation with leaves, e.g. 
"landuse=forest", "natural=wood", "natural=scrub", "natural=tree" and 
others.

Today we have one additional key "wood=" to describe the type of 
leaves. This key is arguable. The oxford dictionary says: "wood = 1. 
The hard fibrous material that forms the main substance of the trunk or 
branches of a tree or shrub. 2. (also woods) An area of land, smaller 
than a forest, that is covered with growing trees."
The usage of ''wood='' for the type of leaves is not suitable because 
wood relates to the trunc, not to the leaves. Maybe it is suitable for 
"natural=wood", but the key also relates to forest, trees, hedges and 
shrubs.

The values "wood=coniferous" and "wood=deciduous" are ambiguous. 
''Coniferous'' describes the kind of seeds, not the type of leaves, nor 
the phenology. ''Deciduous'' describes the phenology, not the type of 
leaves, but it seems that it is used for the leaftype.

''Coniferous'' stand for "cone-bearing seed plants with vascular 
tissue". This plants are mostly needle-leafed, but there also exist 
some with broad leaves.

There is also the value "wood=evergreen" to describe the phenology, but 
not the kind of leaves. This applies to needle-leaved and broad-leaved 
plants.

Other values are ''palm'', ''nipa_palm'', ''eucalypt'', ''filao'' and 
''casuarina''. 

There is no tagging for evergreen broad-leaved plants (e.g. most trees 
in the rain forest), nor for deciduous needle-leaved plants (e.g. 
larchs).

It is very complicated to include all combinations of leave type and 
phenology in one key, especially in consideration that the phenology is 
not known in every case.

We need two distinct keys to describe the type and phenology of leaves, 
suitable for all kind of plants and all kind of keys.

It is advantageous to use new keys, to avoid confusion with changing 
values of an already used key.

Proposal:

"leaf_type=" describes the type of leaves, such as broad-leaved or 
needle-leaved.

"leaf_cycle=" describes the phenology of leaves, such as evergreen or 
deciduous. 


http://wiki.openstreetmap.org/wiki/Proposed_features/leaftype

Rudolf