Answers to the questions

- What happens with mature plantations with exotic species that generated suitable conditions as an habitat for flora and fauna?

In this case, the problem is de degree of xenotipical origin for the main tree

- What happens with shrublands in desert systems, with isolated tree species or associated to specific ecological conditions?

Possibly better named as "savanna with isolated trees"

- Is a woodland an area of trees with less than 3 m high? What should be the minimal density of trees?

3 m. is not a tree if we take into account the universal classification of Raunkiaer. 3 m. have to be named as shrub-----shrubland

Density of trees is very important to define a forest. Shadow given by trees is essential at least in temperate habitats

- Is a woodland a patch of less than 10 has of extension, eg. 1 ha?

It is possible.

- Are water beds "lineal riparian woodlands"?

It depends on the kind of soil that allows the riparian forest to extend out of the margin of the river

- What happens with its potential in the future, eg. an area with no trees but with high density of sprouts?

It is not a woodland. If you are evaluating future potential vegetation you will have to take it into account.

Marcus,

I'm not going to try to answer your full series of questions, but the main one is probably best answered by reference to the FAO Forest Resources Assessment land classification system. Scroll down on this page: http://www.fao.org/docrep/007/ae217e/ae217e00.HTM#P76_3345

There's plenty of detail as well as a definition for a general classification.

A more radical approach would be to define everywhere that trees would become the dominant vegetation (i.e. without human management to suppress them) as a 'woodland' ecosystem. So look at the concrete jungle or an intensively managed farm and imagine what once was and what might be again.

Cheers,

Andrew

Axel, Andrés, Andrew and Winfried; thank you very much for the opinions and citations!

Dear Marcos,

I am afraid I cannot give answer to your questions but I can suggest you a citation that can be of interest, in case you do not know it.

Gasparri et al 2013 (http://www.sciencedirect.com/science/article/pii/S0959378013001593) use the National Forests Resource Assessment Program (UMSEF, 2012:http://www.ambiente.gov.ar/?idarticulo=311) to characterize Chaco woodlands as forest or no forest in Argentina. UMSEF groups continuous dense tree covers of > 20% under their definition of forests. I hope this helps. Regards,

Maria

Thank you very much María. In fact, the problem with the UMSEF or COFEMA definitions is that they generalize the same concepts and criteria to all types of woodlands in a country like Argentina, where the diversity of biomes is very important and the dynamics are very different. Usually concepts about vegetation types are related (although not always) to the structure, and some times the functionality and organization is forgotten.

Best regards

Marcos

G'Day Marcos. Precision in language is the hallmark of good science. Unfortunately much of the terminology describing both structural and functional classifications of ecosystems id very loose. There is an old paper not cited very often (D. Edwards. 1983. A broad-scale structural classification of vegetation for practical purposes. Bothalia 14(3&4) pp 705-712) that gives a precise description of terminology used to describe vegetation types. Because it is detailed, the structural descriptions also usefully describe many aspects of function. If you battle to obtain the reference mail me at [email protected] and I'll send you a pdf copy.

Marcos. This question of what is a woodland or forest or not in terms of science and forest legislation as respects Polylepis dominated woodlands/forests was discussed (and the point of argument) at the III Congreso Internacional de Ecología y Conservación de Bosques de Polylepis in September of 2013 (Chile, Arica). If I remember correctly, Chile uses a different definition than Argentina, one that is broad enough to consider regional differences in "woodland type", however it is trying to currently define what is a Polylepis woodland or what they consider a "bosquete," to differentiate it from the other forested ecosystems in their national territory.

You might want to look up their recently updated forestry & natural resource legislation to see.

For some researchers familiar with other Polylepis dominated woody communities outside of Chile and particularly in more mesic areas, some of the Polylepis communities in Chile and other areas might be considered more shrublands than woodlands or forests in some cases. You have probably discussed this with them, but I recommend that you talk with Ricardo Suarez and Daniel Renison in UN and Conycet- Cordoba to get their perspectives or some more insight into what was discussed regarding Polylepis dominated forests in particular, they have opinions regarding each of your secondary questions.

In terms of differentiating forest from woodland vs shrubland, someone recently suggested to me looking at the biophysical conditions created to define a "functioning"forest. For example, a different temperature regime from an associated surrounding vegetation etc.

in Mediterranean - type ecosystems in the highlands of SW Jordan with evergreen trees/shrubs (e.g. oak and Phoenician junipers) in semi-arid areas, we consider relic, but extensive stands of trees / large shrubs containing "trees" with heights above 2.5 meters and a density of over 10% as (open) woodlands - analysis of bird communities revealed that several typical woodland bird species occur in such open woodlands

Thank you, Bruce, Laura and Fares.

Laura: Indeed, Ricardo and Daniel have been developing very important actions regarding Polylepis australis, a vulnerable species developing nearby I live. This species is sometimes defined as a shrub and sometimes as a tree, which brings me to the question about "how to define a tree"? I guess the same problem is up to Fares with the definition of woodlands in desert or semidesert areas.

In Argentina there are plenty of examples about species considered as trees in some ecoregions and as shrubs in other. Regarding functionality, independently the size of the species, some functions might be the same, however other (like soil coverage) might be different and important.

As Fares says, biological interactions should be considered in the definition of woodlands. Differential characteristics (for "functioning" forests) are important if they can be measured. The difficulty is to define the "control" condition to establish a base line and to "measure" differences between current conditions and healthy, mature and/or "climactic" conditions.

In water-limited Mediterranean-type climate areas, we mapped the natural vegetation taking into account the tree (high greater than 4m) cover from open to dense. Rather to use open or semi dense forests we used open or semi dense woodlands and dense forest.

Serge: what density or coverage had been chosen for each vegetation type?

general ecological texts will define woodland/ forest/ shrubland based on cover (PFC, CCP) and height

In the pass we used aerial photographs for mapping and we retain few classes: lower than 25, 25-50, 50-75 and greater than 75 percent cover. These classes were comparable to those that Australian ecologists used too. Now with high resolution remotely sensed data and image processing tools you could modify them. Interestingly you could compare today cover with ancient maps to quantify changes.

Thank you Bruce and Serge.

Serge: How did you classified the class with less than 25% coverage? Was it considered a woodland? If so, what was the minimum coverage you considered in this class for woodlands?

What bothers me is that generally classifications use arbitrary values of height and coverage without any functional criteria (eg why a 25% cover and not 24 or 26?).

How do you manage this issues?

As I have posted, I think that the main functional criteria, at least in Mediterranean and Temperate and Boreal forests, is the shadow of the trees which eliminates heliophyllic plants.

Hi Marcos:

Your question is quite complex. There are spatial/functional issues involved. You should check the USDA Forest Service woodland definition for the US West as well as concept of potential vegetation vs. existing vegetation which should get you to more stable perception about the theme. Also there are measures in forestry, e.g., stand density index SDI, basal area BA, which can serve, besides a tree cover, as good woodland density assessment.

You may also check pretty recent:

Gottfried, Gerald J.; Shaw, John D.; Ford, Paulette L., compilers. 2008.

Ecology, management, and restoration of piñon-juniper and ponderosa pine ecosystems:

combined proceedings of the 2005 St. George, Utah and 2006 Albuquerque, New

Mexico workshops. Proceedings RMRS-P-51. Fort Collins, CO: U.S. Department of

Agriculture, Forest Service, Rocky Mountain Research Station. 218 p.

Or other rich woodland literature from the US West.

Andrés: Thank you. I agree that treetop shadow can be an important indicator, however, I think a woodland definition should encompass different degrees of coverage. To eliminate heliophytic species you need at least 65% of coverage (at least in the semiarid lands where I measured this) and for example savanna type (among other) woodlands counts with several heliophytic species.

Antonin:

Thank you. I had search US forestry regulations and it is a mess to find out what is the current and accepted definition.

I take this: http://www.cbd.int/doc/world/us/us-nr-vfe-en.pdf, as the most ilustrative and complex document where 7 criteria were defined for the definition of forest lands. It is still very vague because of the lack of concrete values for the indicators, but I also think these should be defined according each ecological context.

Marcos: I think that in savanna-type ecosystems there are few possibilities to find shadow-fitting species. Shadow is important in Mediterranean, Temperate and Boreal ecosystems. In savanna coverage of trees may be the most important factor to consider woodland...

Your questions of ecology maybe can be answered by Eugene P. Odum: fundamentals in ecology.

An area is usually classed as forest or woodland based upon trees being present, the percent crown cover and a minimum area. A tree is often defined by height. Land may called a forest or woodland based upon the use. And land may be labeled as forest based upon ownership...i.e. Ochoco National Forest. In the latter two cases trees may or may not be present.

There are many definitions of forest floating around. I have been collecting them since 1997. If you go to to .http://home.comcast.net/~gyde/DEFpaper.htm you will find over 1600 definitions listed. What one considers a forest depends on the intended use.

A piece of land would no longer be considered forest when it fails to meet your definition.

I don't think there is scientific reason why certain thresholds (such as tree height, crown cover, etc.) are used The thresholds that are used are most likely based upon tradition.

I agree with Gyde. You may feel that there is a gap in information or these information are even vague in terms of woodland indicators, but the true is that woodland definitions came up to set up broad, mostly physiognomy criteria/thresholds. Within these you can study whatever you want.

Thank you Hernán, Gyde and Antonin.

Gyde, I already had your paper. Let me say that it is a very important compilation what you are doing.

In effect, most of the definitions you have compiled center their definition in crown cover and area, and perhaps the differences in the values depend on the physiognomy of the local woodlands.

My concern about the defined values, which are arbitrary, is that they are not flexible at all regarding the local or international laws. Like almost every aspect in conservancy politics, woodlands or other type of ecosystems like wetlands must follow strict conditions that are not even defined for each situation or ecological context, not to say social and cultural context.

Instead of defining ecosystems according to the functioning, dynamics and ecological networks, they are usually framed under artificial structured categories that are usually functional for politicians and land-owners. This happens in my country and I´m pretty sure that also happens in other countries.

What I have seen in the bibliography about criteria for the definition and evaluation of woodlands are mostly structural, and what it is called "complexity", or "functional" criteria is more of the structural kind hidden under indicators that may or not be useful, but they are still a photograph of the condition of the moment. Of course there are exceptions, and these should be applied over all kind of ecosystems, which have among them one thing in common: its dynamism.

Of course, the definition of criteria is not an easy task, especially when we are talking about an enormous heterogeneity of woodlands, forests, or ecosystems. That is why is so important to work the definitions in different scales, especially at local/regional scale, working with local citizens, land-owners, policy makers and specialists.

Indicators should be flexible because ecological systems have diffuse limits and thresholds, and specially, it is often founded EXCEPTIONS to the rules!

Of course I may be wrong, but this is the purpose of this discussion.

The situation is made more complex by different uses of the English words 'woodland' and 'forest' in the US and the UK. To simplify, in the UK the word a 'forest' is an area that has a particular type of public ownership and management, and a 'woodland' is an area with continuous tree canopy (or close to continuous tree canopy). Still simplifying, in the US a 'forest' is a continuous-canopy stand of mostly tall trees, and a 'woodland' has shorter trees and probably a discontinuous canopy, usually because the climate and/or soil cannot support a forest. Hence the northeastern US (mesic temperate climate) has mostly forests and the lower elevations of the US southwestern mountains (arid climate) have mostly woodlands or savannas. The line between woodland (in the US sense) and savanna is determined by the % tree canopy cover, and is discussed in the savanna literature; I am not aware of any consensus on what the % woody cover distinguishing savanna from woodland should be. (There is also no consensus about the % woody canopy cover for the distinction between shrubland and shrub savanna.) And the Australians have their own definitions....

To me there is no single definition of woodlnad, the literature indicates that various authors define woodlands within a given context. In our environment in southern Africa, the main aspects to consider include (but not limited to) canopy cover, tree height, ecosystem stratification, stand density and the functional composition of the ground layer. These are used in combination and help us to differentiate between forests and woodlands. But there may be overlaps, which again boils down to the issues of context. For example:

A woodland is a stand of trees up to 18m high with a canopy cover of 20-80%. Ground layer is dominated by grasses (Timberlake, Nobanda & Mapaure, 1993; Pratt, Greenway & Gwynne, 1966). An open woodland - canopy cover of 20-60% and a well developed grass layer. Crown cover range used by the Australian National Forest Inventory for woodland is 20-50%. Scholes & Hall (1996) use 50-100% tree canopy cover, and a graminaceous layer. There are also various types of woodlands.

On the other hand, forests are different. For example:

They are defined as wooded ecosystems dominated by trees usually having single stems, stand height exceeding 2m and with crown cover of overstorey strata about ≥ 20% (Australian National Forest Inventory). Ranges of crown cover used by the Australian National Forest Inventory are:

open forest: 51-80%

closed forest: 81-100%

Scholes & Hall (1996) define them as having complete tree canopy cover and three or more overlapping vegetation strata. The ground layer is NOT dominated by grasses but by other non-gramineceous herbs and shrubs. There are also open and closed forests, moist/rain and dry forests. The bottomline is that the context in which one defines these ecosystems must be clear from the outset, otherwise there is no 'one-size-fits-all'.

Thank you Norma and Isaac!

It is clear that definitions are diverse both for woodlands and forests.

So what is the purpose of international bureaus like FAO in trying to limit both definitions by determining thresholds? There are even numerous definitions for a same country, taking hand of a particular one according to the interests of the moment and the involved actors.

Perhaps definitions should be limited to broad structural and functional criteria (among other) and the indicators values should be defined regionally (not even nationally) according to local perception.

I think that global environmental mercantilism such as carbon stocks (which personally I think it is tendentious) should refer to this regional criteria.

I don´t understand why international mechanisms like REDD insist only in quantify only trees biomass and not other (and perhaps even more important) carbon sinks such as bushes, grasses and soil carbon, to only mention one of the multiple Clean Development Mechanisms (CDM). Anyway, that is a different discussion.

A woodland usually develops on an area where the annual rainfall is between 300 mm and 1600 mm so long as other conditions are favorable. It is a stand of trees up to 20 m tall. The tree canopy is open or continuous not thickly

A woodland usually develops on an area where the annual rainfall is between 300 mm and 1600 mm so long as other conditions are favorable. It is a stand of trees up to 18 m tall and are usually more branched than columnar. The tree canopy is open or continuous not thickly interlaced thus the canopy is not deep and complex (20 -100%). Woodlands in Africa contain few evergreen tree species but mainly deciduous tree species, usually trees are leafless for part of the year, i.e. shedding their leaves especially during the dry season. Shrubs contribute less than 10% of the canopy, however, grasses and herbs dominate the woodland floor. Thus the presence of heliophilous grasses on the ground layer distinguishes woodland from other vegetation types. Occasionally, some woodlands may have closed canopy and these are referred to as “closed woodlands.” Epiphytes are often present, though relatively rare, except in secondary woodlands on forest site.

Dear Marcos,

To wade through the quagmire of forest definitions is difficult. In the African context wood land is referring to a woodland savannah, as found e.g. in the Miombo or Mopane woodlands of southern Africa as opposed to high forests. The forest cover can be quite dense though in places. So I agree with your analsysis that a density/crown cover definition is difficult, as much as it it would be preferred for quantitative and especially remote sensing applications.

have a look at:

Paxie W. Chirwa, Stephen Syampungani, and Coert J. Geldenhuys Chapter 4

Managing Southern African Woodlands for Biomass Production: The Potential Challenges and Opportunities T. Seifert (ed.), Bioenergy from Wood: Sustainable Production in the Tropics, Managing Forest Ecosystems 26: 67-86

You can also have a look at FAO definitions of Forest and Other Wooded Land applied in the country reporting process for FRA 2015 (http://www.unece.org/fileadmin/DAM/timber/docs/sfm/SOEF2015/FRA2015_Definitions.pdf)

A multi stemmed tree

A 7 meters "shrub" in a 200 mm per year woodland (See above)

A bamboo-tree forest

A tree-cacti community of Stetsonia coryne

Thank you Samwel, Thomas and Maria!

I respond to your opinions with more questions...

Which of the photographs above can be considered trees within forests or woodlands?

A 7 meters "shrub" in a 200 mm per year woodland

The definition of a 'woodland' seems to vary between geographic regions (e.g. a desert woodland will be defined differently from a temperate woodland) as well as between other economic and social factors. Also, the definition of what is a scrub/shrub tree is different. I've worked with the following definitions:

1) From http://www.forestry.gov.uk/website/foreststats.nsf/byunique/sources.html "The definition of woodland in United Kingdom forestry statistics is land under stands of trees with a canopy cover of at least 20% (or having the potential to achieve this), including integral open space, and including felled areas that are awaiting restocking. A tree is defined by its species; a list of tree species in British woodland is given in Chapter 4. There is no minimum height for trees to form a woodland at maturity, so the definition includes woodland scrub but not areas of gorse, Rhododendron, etc., outside woodland. This is a different definition from that used internationally which is based on 10% canopy cover and a minimum height at maturity of 5m, but the two definitions are estimated to give similar areas of woodland in the UK."

2) From the Millennium Ecosystem Assessment www.maweb.org/documents/document.290.aspx.pdf

"In this chapter, ‘‘woodland’’ refers to the type of land cover characterized by trees and shrubs: ‘‘other wooded land.’’ Other wooded land, or OWL, is defined by FRA-2000 as land with a tree crown cover (or equivalent stocking level) of 5–10% of trees able to reach a height of 5 meters at maturity, a crown cover of more than 10% of trees not able to reach a height of 5 meters at maturity (such as dwarf or stunted trees), or shrub and bush cover of more than 10%. OWL excludes areas with the tree, shrub, or

bush cover just specified but of less than 0.5 hectares and width of 20 meters, as well as land predominantly used for agricultural practices (FAO 2000, 2001c). Trees growing in areas that do not meet the forest and OWL definitions are excluded (FAO 2001c)."

Hope this helps!

Taking literally the national definition you provided, a p[plantation would not be classed as a woodland as it is not natural as required by the law/ Shrublands would not be woodlands unless they fit the definition. Likewise an area with trees less than 3 m would not be a woodland as would areas less than 10 ha. If the riparian area met the definition, then it would be considered woodland. The area with a high density of sprouts by definition would not be a woodland at this time. To include any of these would require changing of the definition.

Oops, I was responding to Marcos original question. Sorry about that.

Thank you Stefania and Gyde!

Re-reading all answers I realize that there is no other criteria (except in some academic papers) than the structural one, mainly based on the presence of trees, its crown coverage and height. And there are not even common threshold values among all definitions from around the world. It is sad because forests and woodlands, like any other plant formation are dynamic systems and they are continuously changing.

I can´t find any other criteria for the definition of woodlands than the structural one, a photograph of the system in the moment it is seen. Not even sprouts or seedling are considered as indicators of the potentiality or trophic networks for the evaluation of their complexity.

It is sad because conservation policies depend on this kind of definitions, and many rural communities depend on the incorporation of these kind of ecosystems into a regulatory background for the maintenance and correct management for sustainable development.

In the “International Code of Phytosociological Nomenclature” (ICPN). 3rd edition Art.29b states: “Strata that are considered to determine the vegetation structure, must have the mean dominance degree of over 25 % (at least the value 3 of the Braun-Blanquet coverabundance scale)”. Since in woodland the trees represent the highest stratum, a wood is given if trees (including their crowns) form more than 25% of the ground cover.

BB founded the Montpellier-Zurich school of phytosociology. My CNRS lab in Montpellier partly originated from that. I suspect that the tree cover thresholds I gave to you days ago sources from the phytosociology. Don’t remember too that before the second war the maps have been drawn only from field surveys. The black and white photos arrived later after the second war.

Thanks Heinrich and Serge.

Indeed, BB method is a useful tool that helped me in many cases in the definition of plant communities, based on the frequency and plant cover.

Nevertheless, it is a method that is generally not well received by some forest researchers and policy makers because it is not understood and is believed to be very subjective, which I think it is not.

Marcos - FAO, for its periodic Global Forest Resource Assessment (FRA), does have a standard definition of forest that countries are to follow when reporting statistics on their lands. You may view the latest for the 2015 assessment at http://www.unece.org/fileadmin/DAM/timber/docs/sfm/SOEF2015/FRA2015_Definitions.pdf. A standard definition provides the opportunity to compare one country with another and to aggregate to a global total without adding apples to oranges. That is for the global assessment. Many countries have their own definitions for their national. reports. As I mentioned before, see http://home.comcast.net/~gyde/DEFpaper.htm where you will find many national and international definitions of forest and woodland. Warning, this is a big file and may take a while to load. Thus one may find two or more estimates for forest land for any given country but based upon different definitions.. When reading or citing any forest land statistics make sure you understand what is the definition used (assuming those that are reporting followed the definition.

Dear Gyde:

It is clear to me that there´s need to establish a common definition for forests for statistical comparison in time and space, for comparing deforestation rates, plantation surfaces, etc., etc.

However, I insist that the generalization of a single definition for forests and/or woodlands restrict its functioning to coverage, density and tree height, and I feel it is necessary for us to begin working in a wider definition encompassing other aspects than the structural ones.

Forests (or woodlands) are not reduced to a group of trees, but they have several strata, they act as biological corridors, they regulate water flows, they are habitat for several species, etc. There are several degrees of woodland quality and functions, each can offer some environmental services, different from others.

In our deserts, "other wooded lands" (based on FRA 2000) are at least or more important for some functions than "true forests", and they are not legally protected for the blind and structured definition of "forests".

It is well studied that these kind of ecosystems (other wooded lands) have a very important (and fragile) function over soil-water-atmosphere-human tetrade that needs to be considered within legal protection (under forest or other kind of vegetation type).

For instance, in some countries it is acknowledge that some "non-tree like" species like bamboo in Japan or palms in Argentina are quite important for conservancy like forests are, so they are included into the forest definition. What happens with other species, such as saguaro or shrubs?

Is it equally important to maintain a tree coverage over 20% in a temperate-semihumid area than in a subtropical-desert like forest?

For areas with less than 500 mm it is well proven that tree cover below 40% can be un-sustainable for soil quality, while temperate areas can (more or less) maintain original soil characteristics with lower tree coverage.

I write this in order to follow the discussion...

Hi Marcos – I agree with you that it would be desirable to have more descriptors in the definitions ‘forest’ or ‘woodland’. Check out: Beyond the trees: information needs for sustainable forestry - http://home.comcast.net/~gyde/2001spain_beyond_forests.doc.; Information and inventories to support sustainable forest management - http://home.comcast.net/~gyde/2000spain_inv_info.doc; Information needs assessment - http://www.etfrn.org/etfrn/newsletter/news36/index.html and Attributes and technologies for global vegetation classification, mapping, and monitoring. http://home.comcast.net/~gyde/1995veg_class_tech_thailand.doc .

However the development of such definitions is easier said than done. (You may wish to check out Definition of Low Forest Cover (LFC) - http://home.comcast.net/~gyde/LFCreport.html.)The purpose of having a defintion is so that you and I upon visiting the same location separately come to the same conclusion. Attributes like tree height, canopy cover, and area are rather easily measured and observed. Things like strata, biological corridors etc. are not so easy to describe so we see things alike (try it!).

Even if a more detailed definition can be developed, people may interpret it differently. Over the past several years I have administered ‘test’ to see how consistent a definition is applied using the simple thresholds of area, canopy cover and tree height. ‘Students’ were shown a series of slides of different land cover or land use situations. They were given a definition to follow and using that definition decide if an image depicted ‘forest’ or not. I have given the test to professional foresters, inventory specialists, remote sensing experts, rangeland managers, university students and professors, etc. in the USA, Canada, Australia, Finland, Italy, Costa Rica and Mexico. On the average there was about 70 percent agreement among the people on any particular image. See Forest – Now you see it. Now you don’t! http://home.comcast.net/~gyde/forestnowsee.doc.

Regardless if you are preparing a report about forest area, make sure you include the defintion you use. . Others may not like your defintion, but they should not question the results if you followed the defintion to the letter. See The Need to Say What You Mean and Mean What You Say - http://home.comcast.net/~gyde/2003Helms.doc. When developing a definition or threshold make sure you understand what it means if a change takes place. If you use a threshold of 40 percent and either a natural or human event occurs and reduces the cover to 39 percent – is the area still considered ‘forest’? If not, since the area was classed as a ‘forest’ and is now ‘non-forest’ is the area now considered ‘deforested’? If the area is still considered ‘forest’ then the defintion needs to be changed to permit lower canopy coverage.

I have long been a proponent of moving away from terms like forest and woodland and recording more the attributes rather than throwing things into a specific class. See: Omissions, commissions, and decisions: the need for integrated resource assessments. - http://home.comcast.net/~gyde/2000omission_journal.pdf and Coming to terms with politicians and definitions -. http://www.iufro.org/download/file/552/387/op14.pdf. If attributes are recorded, then the user can sort the data by which ever criteria wants to use.

Anyway, these have been some of my thoughts. Thanks for bringing up my favorite topic. Cheers, Gyde.

Dear Gyde:

Thanks for the comments and the links (unfortunately some of them are dead links) , they are quite enriching for a wider discussion about land use. I totally agree that classifications are tricky (although they are sometimes necessary), and that the sum of attributes should be encompassed within more flexible thresholds.

Recently I had the fortune to coordinate some workshops for the definition of different land uses, where criteria, indicators and thresholds were defined, not so much according to legal definitions, but to local experiences, and where traditional knowledge was the most valuable information.

Indigenous people, peasants and land owners in general, who make daily use of their land resources should be those who contribute in the definition of land use, conditions, criteria and indicators, but not letting aside scientific knowledge, under the local natural, social, economical, cultural and technical context. I believe this is the best way for a sustainable use and better conservation of natural resources.

Hi Marcos Try the following:

Lund, H. Gyde. 2002. Information Needs Assessment. ETFRN News No. 36: 8-15. European Tropical Forest Research Network, Wageningen, The Netherlands. http://home.comcast.net/~gyde/2002ina.doc

Lund, H. Gyde. 1999. Definition of Low Forest Cover (LFC). Report prepared for IUFRO. Manassas, VA: Forest Information Services. 22 p. http://home.comcast.net/~gyde/LFCreport.html or http://home.comcast.net/~gyde/1999lfc_report.doc.

Lund, H. Gyde. 2006. Forest – Now you see it. Now you don’t! Gainesville, VA: Forest Information Services. 18 p. http://home.comcast.net/~gyde/2006forestnowsee.doc.

Lund, H. Gyde. 1993. Politically-correct global mapping and monitoring. In: Falconer, Allan, ed. Mapping Tomorrow's Resources; 23-24 April 1992; Logan, UT. Natural Resources and Environmental Issues Volume II. Logan, UT: Utah State University; College of Natural Resources: 47-54. http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1030&context=nrei or http://home.comcast.net/~gyde/1993politically_correct.doc

Re the indigenous people - I am working on list on the topic on their use in natural resource inventory and monitoring. I am not doing any synthesis - just preparing a list to share with some e-lists to which I belong.

Please let me know if they work for you. Cheers, Gyde

Dear Gyde:

Thank you very much. They are all functioning. I´m reading them now.

Cheers

Hi Marcos - You and otherrs may be interested in the Global Forest Watch (GFW). learnt what is happening in forests right now worldwide. See http://www.globalforestwatch.org/. .

For its defintion of forest, "GFW does not aim to provide a consensus definition. Data sets hosted on GFW may define “forest” differently or pertain to different types of forest (primary, secondary, tree plantations, etc.). Through information found on the Data page, we aim to be transparent about the assumptions and definitions feeding into each data set. In our general writing, including the GFW blog, “forest” refers to a landscape with a high density of trees and value for biodiversity, carbon storage, and human use."

Tree cover is differnt from forest. "Where found on the GFW website, “tree cover” refers to the biophysical presence of trees, which may be part of natural forests or tree plantations. The inclusion of all types of tree plantations in the “tree cover” definition notably distinguishes the term from some definitions of “forest.” Accordingly, “tree cover” and “forest” should not be used interchangeably. Different data sets further define “tree cover” with added parameters "

See http://www.globalforestwatch.org/howto#terminology .

Wow! Impressive design of the webpage. Thanks for the information Gyde

Hi Marcos

Forest inventory can be the criterion.woodlands have Stock Under 100 sylve (Volume of Live trees).

Have a look at our published analysis of a time series of FAO FRAs in Rwanda for an idea on some of the forest versus woodland definition issues raised in this Q&A.

Article A comparison of fine resolution census and image-based natio...

Dear Marcos,

Even in an environment as arid as Yemen, 'woodland' exists, at least we defined a structure based on cover of trees (>3 m) and shrubs (1-3 m), see  for its caracteristics and application:

Conference Paper Defining a legend for the future vegetation map of Tropical ...

Data Veg-Map-Yemen-Scholte et al.