[Tagging] Feature Proposal - RFC - shrubbery

Mon Feb 22 13:10:56 UTC 2021

Dear all,

I applaud Vincent for doing his very best to try to find a compromise
for the different objections and improvements proposed so far.

I think we are very close to reaching a general consensus but it still
needs some fine-tuning to achieve this. I carefully watched the first
discussion yesterday, sitting back, analysing and researching all the
arguments brought forward.

1.*Create and justify a new top level key value for these features ?*  I
think I was the first one who brought up the suggestion to let these
features reside under scrub, both to cater for the scientific user as
the common mapper. Additionally arguments were to keep the structure and
use of our natural tagging - with a limited number of top-level distinct
values and detailing through attribution.
To me, and correct me if I am wrong, the majority here, it is generally
accepted that this is such a common type of vegetation and commonly
referred to in different terms, that Vincent's proposal justifies
creating a new natural top-level value group. It doesn't need further
discussion and it will not stop me from supporting this proposal.

2. *What is the most commonly accepted and suitable word in English for
the new top-level value in natural?* In this I tried to understand
Vincent's justification in the proposal and in regard to previous
discussions. The proposal had some history as it moved from bush or
bushes, to shrub.  Was there a good reason to introduce a new term
"shrubbery" in regard to the previous "shrub".  In my honest opinion no,
unless Vincent had also in mind to use a term "shrubbery", which
describes very distinctive garden practices in traditional English
gardening, to link the features he is targetting to gardening or
"decorative" use as such, trying to avoid discussion? This doesn't seem
to work.
When I look back to the history of the proposal, there was good grounds
to choose shrub instead of bush as that is the most commonly used term
in the scientific world and is understood and used by most communities
using English. It didn't have much objection in the previous discussion
if we agreed on 1, in the contrary it is a good indication that in many
cases it can cause some overlap with natural=scrub since scrub also
contains shrubs, an overlap or gap which we should try to reduce with a
more distinctive detailed definition.

So in my opinion, best to leave it natural=shrub.

3.*Is a clear definition provided that minimises the overlap with other
natural tags ?* In my opinion no, some improvements are needed. In all
good intentions Vincent tried, but using some objective terms, like
"wild" or "decorative", and not clear understood subjective terms like
"cultivation or cultivated land".
3a. Use of the term "wild".  I asked myself, what is considered "wild". 
A shrub that grows in a natural way, but shaped on a regular basis by
humans, no discussion, no one can call that wild. A shrub that is
planted by humans, but for various reasons after planting, not shaped by
humans.  We enter the grey zone, some might consider it wild because it
is and can continue it's growth in a natural way, some might consider it
not wild because humans might control it's reproduction or spreading by
removing seedlings, shoots and seeds. Is scrub, that is confined by
human intervention to prevent it's uncontrolled spreading to be
considered still wild ? Is scrub where humans intervene to remove shrubs
or bushes or undergrowth no longer to be considered as wild, and thus
becomes shrub ? Is it in all cases viable for a mapper in the field to
determine if there was never human intervention so that it be scrub ? I
think the description of both scrub and shrub should not contain the
word "wild".

3b. Use of the term "decorative".  Many people consider shrubs that are
allowed to grow unobstructed by human intervention as very decorative.
More decorative as the neatly trimmed shrubs because they prefer natural
growth. Some shrubs might even require to be grown naturally to achieve
the "decorative" purpose, f.i. to allow them to flower.  So when it is
no flowering season are these plants no longer considered decorative
then ?  Are they to be consider as scrub depending on the season ? I
think we should avoid the term "decorative".
3c. Cultivation or cultivated land. This is a quite clear defined
objective term: it applies to land or individual plants who are worked
upon by humans to produce crops or fruits. Scrub, by definition can only
be found on non cultivated land.  No doubt about it. However, patches of
scrub can be found in cultivated land, and any user should be allowed to
map them indepently of their size.  If the mapper or scientist consider
that patch as significant to ap it that way, it's fine.  Small patches
are mostly there for a good reason, maybe the scrub contains a protected
species, provides a biome or refuge for wildlife, has a cultural
significance, has a historical significance... Should we not map it as
scrub because the main land it grows within is cultivated, situated in
farmland or an orchard ?

A single plant might be cultivated, f.i. an apple tree or a berry bush
or shrub in a garden, or on public land. Is it suitable then to use the
term cultivation to define natural=shrub as a major feature.  Is
mulching to be considered as practice to consider a lnd as cultivated,
same as f.i. weeding.  No, because in the case of the shrubs we like to
define, the mulching and weeding is not intended to harvest crops or
fruits from the shrubs.
So in the existing definition of scrub I would keep it, but in shrub, to
distinguish it from scrub, it is not the best choice.

4. *What (subjective) classification principle is the best suited for
OSM* ? I am not a scientist neither a botanist or whatever but I made
the effort to browse to the internet and read some studies about
vegetation classification principles used for mapping purposes.  I
wasn't able to find one single principle that covers our needs but did
identify some common criteria: height of the vegetation and it's
appearance. Height is a general distinction that is used already to
define heath and to distinguish heath from scrub. Height is not clearly
defined as a criteria to distinguish grassland, as we all now some
grasslands contain grasses which can grow up to significant heights like
the dominant elephant grass here in Africa. They are distinguished by
describing there appearance.  Same applies to distinguish wood,
generally regarded as tree coverage, where the height criteria might not
be enough to distinguish it from scrub (scrub contains small trees and
stunted trees), so there is an additional guidance to it's appearance.
What I definitively still don't like about this proposal is that it
tries to limit the group of vegetation we should consider as shrub by
putting limiting criteria in it's definition, and additionally
discourages the use of attribution tags like with scrub=* or in this
case the need of shrub=* which allow data consumers and mappers to
further attribute and map and use the data for their specific interests
or needs.  It is a principle which is slowly getting ground in other
tags to avoid getting an uncontrolled group of endless top-level keys or
values which create a mess, discourages and decreases the usage of our
wiki etc...  Also we should avoid to incorporate any additional
classification that limits or discriminates. I am thinking like
including a term like "it is mostly found inside urban environments". 
So as a mapper or as a local community I should not regard my shrubs in
my garden, on my farm, as a nomad the shrubs I planted and maintain
around my water holes as not being shrubs, but scrubs ?  Do we consider
these as not civilised environments because by defintion it must be
considered scrub that is always "wild".  The opposite, should we
consider patches of remaining scrub, or even patches of shrubs in parks,
gardens etc... in cities, as not to be considered anymore as scrub but
rather as shrub just because of the single fact they grow, still wild
and natural in a city ?
I do think that in the limited number of examples given at this stage
and maybe the limited number of cases identified so far, the proposal
should provide it as optional tagging with some guidance on what we
consider as good practice to assign as values and encourage users to
extend the proposal or the wiki page after approval to add more
examples, more values to the attribution keys.  I am already thinking
about examples like a field or decorative groups of cacti, bamboo, all
to be considered as scrub or shrub and probably miss on many more
examples. Attribution keys are very OK to be extended with subjective
criteria, different classification criteria, in essence any value that a
user see fit or considers as significant enough.

So, after all of this being said in my opinion this propsal has great
potential for success when:

1. Creation of a new natural top value is justified, I support it;

2.  I prefer the term natural=shrub since it has most common ground and
has a general English meaning that complies most with the vegetation
group we are targetting;

3. + 4. For shrub maybe: "Is a group of shrubs or bushes, characterised
by stems with mostly a woody appearance and branches appearing at or
close to the ground. In some cases the stem(s) are not woody like f.i.
in most cacti and some low growing bamboos." This tag should only be
used for vegetation, with this distinctive appearance, that shows a top
foliage not higher then 5m? and not lower then 20 cm ? Similar woody
vegetation lower then shrub should be tagged with natural=heath.
Vegetation showing a higher foliage is to be mapped separately as
individual trees, tree rows or natural=wood or landcover=trees.

For scrub: existing + This tag should only be used for vegetation, with
this distinctive appearance and containing small or stunted tress,,
and/or shrubs and/or bushes, that shows a top foliage not higher then
5m? and not lower then 20 cm ?

How to distinguish scrub from shrub:

Scrub: (this is existing)
Maintained, cultivated areas of landscaping or shrubbery (this usage is
controversial), I propose to change to: When scrub is found where human
intervention is clear to influence it's interior growth or propagation
to serve it's appearance to be more attractive to humans or to control
it's growth to not interfere with other human activities, like
landscaping, gardening, in or on cultivated land, natural = shrub should
be used instead. If the human activity is aimed at controlling it's
propagation at it's boundaries only or to keep it in it's indigenous
natural state, f.i. by clearing invasive species, it is to be tagged as
natural=scrub.
Of course I propose a similar distinction statement for shrubs.

Hope this helps,

Greetings,

Bert Araali

On 21/02/2021 22:37, Vincent van Duijnhoven wrote:
> Based on the discussion on landuse=shrubs|bush, I created a new
> proposal for shrubbery. This proposal proposes the tag
> natural=shrubbery with as definition: "An area of cultivated
> decorative shrubs or bushes"
>
> https://wiki.openstreetmap.org/wiki/Proposed_features/shrubbery
>
> Kind regards,
> Vincent
>
> _______________________________________________
> Tagging mailing list
> Tagging at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging
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