The 20 primary sources reported in i-WESTAT represent the state of the art of current woodfuel statistics as well as historical references that help to understand the relation among sources and the evolution of woodfuel statistics in the last decade. In this respect the primary sources may be classified as “historical” and “updated” as follows.
Historical sources |
Updated sources |
UNECE/ETTS |
Country report |
ENDA/IEPE |
FAOSTAT (2003) |
ESMAP |
GFPOS 1970–2030 |
Eurostat 89–94 |
IEA (2002) |
FAOSTAT (1998) |
OLADE 90–02 |
FUNBAR |
Other national [includes also old references] |
IEA non OECD 99 |
UN energy statistics (2002) |
IEA OECD Wf 80–94 |
|
LBL |
|
OLADE 80-97 |
|
RWEDP |
|
UN energy statistics 1995 |
|
WETT99 best estimate |
|
A summary description of the primary sources is given in Table 3. The statistics provided by the various sources are heterogeneous in terms of geographic, thematic and temporal coverage. Appendixes 5 to 10 provide detailed statistics on primary sources data concerning the following aspects:
- Temporal coverage
- Number of records by item
- Sector subdivision
- Rural-urban area subdivision
- Geographic coverage
- Typology of secondary reference data
TABLE 3
Summary description of primary sources included in i-WESTAT grouped as “updated
sources” and “historical sources”.
Updated sources |
|||
Code |
Primary Source |
Description |
|
3 |
Country report |
Thematic country studies on wood energy statistics carried out in the framework of the FAO/EC Partnership Programme on Sustainable Forest Management (2000–2002), supervised by FAO. The country studies are based on national information from national and local surveys and other supporting material. Usually providing short time series based on observed data rather than pure modeling. Strong points. In general, the studies represent the best “blend” of forestry, energy statistics and of scattered and fragmented data that are not available outside the countries. Weak points. The quality of these studies varies considerably depending on the authors’ capacity to integrate inter-sectoral information and on the quality of reference. Covering 39 countries only. |
|
25 |
FAOSTAT (2003) |
This primary source includes all data extracted from FAOSTAT forest products statistics and includes data up to 2003 (release September 2004). Original FAOSTAT data include official statistics (provided via questionnaire) or, if official data are not available, unofficial statistics and FAO’s own estimates (approx. 60 percent). Since 1998, FAO, UNECE, Eurostat and ITTO share a joint forest sector questionnaire. FAOSTAT estimates are since 2001 based on GFPOS models. In i-WESTAT the values are reported directly as can be found in FAOSTAT (e.g. charcoal statistics), or derived from original FAOSTAT items (see below for detailed explanation). Strong points. The original FAOSTAT wood products statistics allowed definition of the widest range of woodfuel items. Practically all the countries of the world are included. Longest temporal coverage (1961 to 2003). FAO’s own estimates (based on GFPOS models) are objectively documented. Weak points. There is no information on the sources and estimation procedures of official statistics, which prevents their reliability from being assessed (a condition common to most sources). National correspondents are mainly from the forestry sector, which may induce an underestimation of fuelwood production and consumption. No sector and area subdivision in consumption statistics. |
|
30 |
GFPOS 1970-2030 |
Set of models for the prediction of fuelwood and charcoal consumption in all countries of the world. As many as eight charcoal models and nine fuelwood models were developed in the framework of the Global Forest Products Outlook Study. The aim of these models was that of providing best possible estimates to fill data gaps in FAOSTAT forestry statistics. Strong points. Except “FAOSTAT” models, all other models were based on well documented field survey data (mostly sub national surveys) distributed all over the world. Apart from their use as gap filling, the models can serve as adjustment functions to project in time single-point data of known reliability. Weak points. The “FAOSTAT” models, which were based on official statistics (of unknown reliability) for the countries with over ten official entries, are not necessarily providing realistic trends. |
|
34 |
IEA (2002) |
Apart from FAO sources, IEA maintains the most comprehensive set of wood energy statistics. Since 1999 the Energy Statistics Working Group (IEA, the UN, UNECE, Eurostat and their respective member governments, has decided to develop a common, specific questionnaire on renewables and wastes. IEA publishes statistics on charcoal and on primary solid biomass, which includes wood and non-wood biomass. IEA also keeps disaggregated statistics on wood and black liquor, which were provided and included in the database. Strong points. Directly linked to national energy statistics that produce more realistic consumption estimates. Consumption data are subdivided by sector. Increased efforts, in recent years, for producing better statistics on renewable energy sources (including biomass) and for disaggregating the statistics. Weak points. Available for “only” 127 countries. Published IEA statistics are still limited to primary solid biomass. Estimation as well as disaggregating procedures are not known. |
|
31 |
OLADE |
OLADE collects and harmonizes national energy statistics from 24 American countries. This source is used as main reference by IEA and by WETT99. OLADE’s main references are national energy balances produced by energy agencies. Strong points. Directly linked to national energy statistics that produce more realistic consumption estimates. Weak points. Estimation procedures are not known. |
|
7 |
Other national |
Miscellaneous documents addressing energy issues, including woodfuels, which were assembled mainly, but not exclusively, during the WETT Africa and Asia studies. In the majority of cases this source refers to energy statistics and thematic country studies. Strong points. National-level data. Weak points. Very heterogeneous in terms of original items, unit and coverage. Very wide temporal distribution, mostly out of date, especially those for Africa. |
|
27 |
UN energy statistics (2002) |
UN energy statistics on fuelwood and charcoal refer almost exclusively to FAOSTAT, especially since 1996. Charcoal statistics for a few countries are estimated directly by the UN Energy Statistics Division. Strong points. Wood energy is incorporated within energy statistics. Weak points: Practically a copy of FAOSTAT values, except that FAOSTAT’s “wood fuel, including wood for charcoal" is presented as “fuelwood”, which is not entirely consistent. The estimation procedures of non-FAOSTAT values are not known. |
|
Historical sources |
|||
18 |
UNECE/ |
Dataset extracted from the UNECE European Timber Trend Study V, which was used as one of the references in WETT99. Now only useful as a historical dataset to understand the relation between data sources in past estimates. Strong points: historical reference. Weak points: Out of date: data include only 1980 and 1990. |
|
15 |
ENDA/IEPE |
Jointly with the IEPE (Grenoble, France), ENDA (Senegal) issued a synoptic study on the energy situation in French speaking African countries in 1995. The study did not produce time series but collected national-level data. These country data were sometimes used for WETT99 best estimates for African countries. Strong points. Reports original national data. Weak points. Covering 28 countries in Africa. Rather out of date (late 1980s, early 1990s). |
|
6 |
ESMAP |
ESMAP conducted numerous projects in various African countries. Although it never produced aggregated statistics, the numerous project documents contained information on woodfuels that was compiled during the WETT Africa study and sometimes used as reference for WETT99 best estimates. Strong points. Reports original field project data. Weak points. Covering 39 countries in Africa. Out of date (1970s and 1980s). |
|
19 |
Eurostat 89–94 |
Dataset extracted from Eurostat Renewable Energy Resources Statistics (1996), used as one of the references in WETT99 for Europe and OECD. Now only useful as historical dataset to understand the relation among data sources in past estimates. Strong points. Historical reference. Weak points. Out of date: data are only for1989 to 1994. |
|
10 |
FAOSTAT (1998) |
Dataset extracted from FAOSTAT 1998 statistics and used as one of the references in WETT99 and in the analysis of the country reports done in the framework of the FAO/EC Partnership Programme on Sustainable Forest Management (2000-2002). Now only useful as a historical dataset to understand the relation between data sources in past estimates. Strong points. Historical reference. Weak points. Out of date. Data replaced by new statistics reported under 25: FAOSTAT (2003). |
|
16 |
FUNBAR |
Dataset extracted from FUNBAR 1990 statistics and used as one of the references in WETT99. Now only useful as a historical dataset to understand the relation between data sources in past estimates. Strong points. Historical reference. Weak points. Out of date: data include only 1980, 1985 and 1990. |
|
8 |
IEA non-OECD 99 |
Dataset on charcoal consumption extracted from IEA 1999 statistics and used as one of the references in the analysis of the country reports done in the framework of the FAO/EC Partnership Programme on Sustainable Forest Management (2000–2002). Now only useful as a historical dataset to understand the relation between data sources in past estimates. Strong points. historical reference. Weak points. Out of date. Data replaced by new statistics reported under 34: IEA (2002). |
|
20 |
IEA OECD Wf 80–94 |
Dataset extracted from IEA 1996 statistics, which was used as one of the references in WETT99 for Europe and OECD. Now only useful as a historical dataset to understand the relation between data sources in past estimates. Strong points. Historical reference. Weak points. Out of date. Data replaced by new statistics reported under 34: IEA (2002). |
|
21 |
LBL |
Dataset extracted from Lawrence Berkeley Laboratory Energy Statistics, which was used as one of the references in WETT99 for Europe and OECD. Now only useful as historical dataset to understand the relation between data sources in past estimates. Strong points. Historical reference. Weak points. Covers only nine countries. Out of date. Data limited to the period 1980–1992. |
|
17 |
OLADE |
Dataset extracted from OLADE 1997 statistics and used as one of the references in WETT99. Now only useful as a historical dataset to understand the relation between data sources in past estimates. Strong points. historical reference. (Includes estimates probably obsolete, for the period 1970–1989 which are not included in new OLADE set data). Weak points. Out of date: Data replaced by new statistics reported under 31: OLADE 90-02. |
|
13 |
RWEDP |
Estimates identified as best reliable in the framework of RWEDP. Mostly referring to figures reported under primary sources (3) and (7). Strong points. National-level data. Weak points. Limited to 16 (RWEDP) countries and to 1997. Selection procedure not documented. More comprehensive regional comparison was conducted by the WETT Asia study. |
|
11 |
UN energy statistics 1995 |
Dataset extracted from UN energy statistics 1995 and used as one of the references in WETT99 and in the analysis of the country reports done in the framework of the FAO/EC Partnership Programme on Sustainable Forest Management (2000-2002). Now only useful as historical dataset to understand the relation between data sources in past estimates. Strong points. Historical reference. Weak points. Out of date. Data replaced by new statistics reported under 27: UN energy statistics (2002). |
|
1 |
WETT99 Best estimate |
“Best estimates” produced in the regional studies of the WETT series. The studies were conducted in 1999–2000 and reviewed all national and international information available at that moment. The studies concluded by selecting the most reliable data sources (the data was then labeled as “best estimates”) or produced new time series based on reliable point data, projected thereafter based on per capita values and population growth statistics. Strong points. Based on expert critical review of all available sources. Perfectly reflecting the Unified Wood Energy Terminology, the estimates produced cover all items. Including almost all countries of the world. Weak points. Reference data are rapidly outdated. National statistics and country reports often referred to the 1980s. International databases identified as best references, such as FAOSTAT, have changed their time series on account, it is to be hoped, of new evidence. |
|
The flow of information that feeds the primary sources is extremely complex, as is shown, tentatively, in Figure 1. Wood energy statistics originate from two sectors: the forestry sector, shown on the left side of the figure; and the energy sector, shown on the right. The level of integration between the perspectives of these two different sectors is still quite low, which explains some of the main discrepancies between data sources.
The first critical aspect is that there are very limited field data. Second, and to some extent as a consequence, the information produced by primary sources is based on a great number of estimates, extrapolations, modeling and cross-referencing. Third, the original field reference data are not known or not reported and the descriptions of estimation procedures are extremely rare. In practice, it is impossible to rate the reliability of database entries. Nonetheless, in order to qualify the data with the best possible approximation, each record has been ranked by “reference type” according to the data sources or estimation approaches described in metadata and other available documentation (see Table 10 in Chapter 4). The results of this typology are summarized in Appendix 10. In addition, Appendix 10 provides a tentative reliability ranking, established with the assumption that field survey data are most reliable and that the further from the “field survey” level, the lower the reliability.
FIGURE 1
References of main sources
FAO forest products statistics report forestry data provided by member countries, with some license to fill data gaps with estimates. The concept of forest and forest functions continued to evolve in the past decades to include elements such as “trees outside forest”, “other wooded lands”, “urban forestry”, “agro forestry”, “carbon sink” and “wood as fossil fuel substitute”, which required, and still requires, re-defining the information to be collected and reported on. The process of adaptation to this moving target poses considerable stress on national (and international) forestry agencies.
Practically every forestry institution is involved in this process of adaptation and their capacity to provide consistent data varies considerably. This condition strongly affects wood energy statistics, which concern forestry and energy aspects, including forest and non-forest wood resources whose flow is almost entirely informal. 2
Some national agencies provide only official and formally recorded statistics of fuelwood and charcoal produced in state forests (capturing as little as 10 percent of the true production), while other national agencies provide less official (but more realistic) production statistics derived from consumption surveys conducted usually by energy agencies.
In 1998 FAO UNECE established a working group with Eurostat and ITTO for the joint collection and compilation of data on forest products. For this purpose a joint questionnaire was created. Each member of the group is responsible for the collection of information from a defined group of countries. The statistics are then collated and published by FAOSTAT.
In cases where questionnaire data (official figures) are not available, FAO can quote authoritative national sources (unofficial figures) or can produce its own estimates (FAO estimates). The latter case was traditionally resolved by using the best per capita consumption estimates and population statistics to estimate total consumption. This approach has been criticized as too simplistic and therefore, since 2001, FAO estimates are based on GFPOS models (see below).
FAO forestry statistics include the world’s most comprehensive data series on wood products and as such they provide the most coherent and consistent input to the quantification of woodfuel flows. However, except for charcoal, which is treated in FAOSTAT as a separate commodity, all other i-WESTAT items were arithmetically deducted from the original FAOSTAT statistics. Tables 4 and 5 describe the relevant FAOSTAT items and their re-elaboration to generate the i-WESTAT items included in the database.
TABLE 4
FAOSTAT parameters and temporary codes
FAOSTAT items |
Units |
Production |
Imports |
Exports |
Woodfuel, including wood for Charcoal |
‘000 m3 |
FAOWfProd |
FAOWfImp |
FAOWfExp |
Wood charcoal |
‘000 tonnes |
FAOChProd |
FAOChImp |
FAOChExp |
Wood residues |
‘000 m3 |
FAOWResProd |
FAOWResImp |
FAOWResExp |
Chemical pulp |
‘000 tonnes |
FAOCPulpProd |
FAOCPulpImp |
FAOCPulpExp |
Semi-chemical pulp |
‘000 tonnes |
FAOSCPulpProd |
FAOSCPulpImp |
FAOSCPulpExp |
Fuelwood items were calculated by deducting from FAOSTAT’s wood fuel the equivalent of charcoal production (import, export) and adding a fraction of wood residues. The fraction of residues from wood industries actually used as fuel (usually in the industries themselves) is not known. As an approximation, 50 percent of residues were included in the calculation of fuelwood items, as indicated by the WETT Latin America study [6]. As regards black liquor, it was assumed that the entire amount produced is used as fuel directly by pulp industries.
Conversion factors are provided in Appendix 3.
TABLE 5
Generation of i-WESTAT items for FAOSTAT (2003)
| Fuelwood items | |
| FwProd (‘000 m3) | = FAOWfProd (000m3) – FAOChProd (000 tonnes)/0.165 + FAOWResProd/2
|
| FwImp (‘000 m3) | = FAOWfImp + FAOWResImp/2 |
| FwExp (‘000 m3 |
= FAOWfExp + FAOWResExp/2 |
| FwCons (‘000 m3) | = FwProd + FwImp – FwExp |
|
Charcoal items |
|
| ChProd (000 tonnes) | = FAOChProd |
| ChImp (000 tonnes) | = FAOChImp |
| ChExp (000 tonnes) | = FAOChExp |
| ChCons (000 tonnes) | = FAOChProd + FAOChImp – FAOChExp |
|
Transformation loss |
|
| TraLoss (PJ) | = ChProd (‘000 tonnes)/0.165*0.01005 – ChProd (PJ) |
| Black liquor |
|
| BlkLiq (PJ) | = FAOSCPulpProd (semi-chemical, ‘000 tonnes) * 2.27 * 0.01005 + FAOCPulpProd (chemical, ‘000 tonnes) * 2.27 * 0.01005 |
|
Aggregated woodfuels |
|
| WfProd (PJ) | = FwProd (PJ) + ChProd (PJ) + BlkLiq (PJ) |
| WfCons (PJ) | = FwCons (PJ) + ChCons (PJ) + BlkLiq (PJ) |
| WfImp (PJ) | = FwImp (PJ) + ChImp (PJ) |
| WfExp (PJ) | = FwExp (PJ) + ChExp (PJ) |
Original FAOSTAT figures are defined according to their sources, as reported in Table 6. This information was reported as source 2 for all FAOSTAT (2002) data. In the case of derived figures, source 2 reports the source of the main component of the aggregation. In the case of fuelwood production and consumption (FwProd and FwCons) the source information refers to FAOSTAT wood fuel production. In case of charcoal consumption (ChCons), the source information refers to charcoal production (ChProd).
TABLE 6
FAOSTAT source categories
FAOSTAT code |
Description |
i-WESTAT source 2 code |
No code |
Official figure (government figures in questionnaire) |
97 |
* |
Unofficial figure (authoritative non-governmental source) |
109 |
T |
Trend: repetition of last official figure |
250 |
F |
FAO estimate |
18 |
M |
Missing value |
Not included |
Modeling of fuelwood and charcoal consumption
The modeling exercise carried out in the framework of the Global Forest Products Outlook Study [11] had the goal of supplying best possible estimates of fuelwood and charcoal consumption to fill FAOSTAT information gaps. It responded to the concern over previous FAO estimation procedures, basically projecting woodfuel consumption on population growth, which was considered over simplistic.
GFPOS models were based on a range of independent explanatory variables encompassing income, forest area, the urban population proportion and a range of dummy variables.
A total of 17 models were developed (Table 7), belonging to two sets:
• Set of models based only on the FAOSTAT dataset, limited to the countries that supplied at least ten valid questionnaires, used to estimate and project total fuelwood and charcoal consumption;
• Set of models based on all available information, including a relatively rich data set of national and subnational field surveys assembled for the purpose from “grey” literature3 and FAOSTAT entries, used to estimate household and non-household fuelwood consumption and total charcoal consumption.
TABLE 7
GFPOS model types and countries of application
Model type |
Countries |
||
Fuelwood consumption models |
|||
FAOSTAT 1 |
FAOSTAT model relating the log of total national fuelwood consumption to the log of GDP PPP in 1997 (US$) |
14 |
|
FAOSTAT 2 |
FAOSTAT model relating the log of total national fuelwood consumption to the log of population |
12 |
|
FAOSTAT 3 |
FAOSTAT model relating the log of per capita fuelwood consumption to the log of per capita GDP PPP in 1997 US$ |
20 |
|
FAOSTAT linear |
F Linear- FAOSTAT model relating total national fuelwood consumption to GDP PPP in 1997 (US$) |
2 |
|
FAOSTAT constant |
F constant - Constant total national fuelwood assumption |
1 |
|
National household model + National non-household model |
2 |
||
National household model + Continental non-household model |
11 |
||
Regional household model + Continental non-household model |
142 |
||
Regional household model + National non-household model |
1 |
||
Charcoal consumption models |
|||
F1 FAOSTAT |
FAOSTAT model relating the log of total national charcoal consumption to the log of GDP PPP in 1997 (US$) |
3 |
|
F2 FAOSTAT |
FAOSTAT model relating the log of total national charcoal consumption to the log of population |
1 |
|
F3 FAOSTAT |
FAOSTAT model relating the log of per capita charcoal consumption to the log of per capita GDP PPP in 1997 US$ |
1 |
|
F4 FAOSTAT |
FAOSTAT model relating the log of per capita charcoal consumption to the urban proportion of the population |
2 |
|
FAOSTAT linear |
FAOSTAT model relating total national charcoal consumption to the urban proportion of the population |
6 |
|
FAOSTAT constant |
Constant total national charcoal assumption |
1 |
|
Global model of total consumption model |
180 |
||
National model of total consumption model |
11 |
||
The FAOSTAT fuelwood consumption models were based on the fuelwood fraction of the broader FAOSTAT category “wood fuel including wood for charcoal”.
Beyond providing “gap filling” estimates, a promising additional application of GFPOS modeling is to serve as an adjustment function for short- and long-term consumption projections based on new reference data.
The dataset collected and harmonized for model development includes data from over 160 countries on woodfuel consumption at national and sub-national level, by sector and by area over the period 1960-1999. The dataset is extremely heterogeneous in terms of representation and reliability but nonetheless it represents a valuable effort that deserves to be pursued.
IEA energy statistics for non-OECD countries present historical series for the aggregated item primary solid biomass (PSB) and for charcoal over the period 1971–2002.
The statistics for OECD countries present historical series for the aggregated biomass PSB and for charcoal over the period 1960–2002. Charcoal data seem to be incomplete. (In Europe, charcoal statistics are available only for Italy).
IEA metadata do not provide specific information on the sources of charcoal and PSB data. However, since the sources cited for “renewables and waste” are probably relevant also for charcoal and PSB, these were quoted as secondary sources.
In addition to Web-published data, the IEA Statistical Division provided disaggregated primary solid biomass data, which included the categories wood and black liquor. Table 8 lists the most relevant parameters and the correspondence with i-WESTAT items.
TABLE 8
i-WESTAT items from IEA statistics
IEA item |
Flow |
WEIS item |
Sector |
Area_U_R |
||
WOOD |
||||||
FINCONS |
Final consumption |
= |
FwCons |
All |
All |
|
RESIDENT |
Residential |
= |
FwCons |
Household |
All |
|
FINCONS less RESIDENT |
Consumption in all other sectors |
= |
FwCons |
Non-household |
All |
|
BLACK LIQUOR |
||||||
INDPROD |
Indigenous production |
= |
BlkLiq |
All |
All |
|
Except for a few own estimates, UN statistics on fuelwood (and, to a lesser extent, on charcoal) are taken from FAOSTAT, at least since 1996.
UN Fuelwood Production data directly use the FAOSTAT values for production of “wood fuel including wood for charcoal”. Therefore, for the user of UN statistics the values refer to fuelwood only. Accordingly, in i-WESTAT the item for the UN values is FwProd, although this is not entirely correct. In order to explain the relation with FAOSTAT, the secondary source for all these UN values states: “FAO forestry statistics (FAOSTAT) ref. FAOSTAT item: production of ‘wood fuel, including wood for Charcoal’”.
UN charcoal production data are partly estimated by the UN Statistical Division, partly taken from FAOSTAT values and partly from other sources (not specified).
Eurostat statistics do not include specific fuelwood and charcoal data. In the yearly statistics data 2002 by country, under the renewable energy source “biomass”, the category “wood and wood waste” is reported separately from “municipal solid waste” and “biogas”. However, despite this definition, the “wood and wood waste” category includes lignocellulosic biomass from agro residues and corresponds practically to the IEA category primary solid biomass (PSB, see definition under IEA section). In fact, for European countries, Eurostat statistics on “wood and wood waste” are the IEA main reference for PSB. In view of this, Eurostat data were not included in i-WESTAT.
The woodfuel data reported under “WETT99 best estimates” represent the result of the regional analyses of wood energy statistics carried out by FAO in the years 1997–2000. They assemble what were considered the best references available at the time of the regional studies. They reported existing time series (i.e. FAOSTAT 98 and OLADE 80–97), or were built upon single-year figures from “reliable” sources (i.e. ENDA/IEPE, ESMAP, other national) using per capita consumption estimates and population statistics. Table 9 shows the sources used as best references.
TABLE 9
Information sources of WETT99 best estimates: percentage of fuelwood and
charcoal consumption estimates
FAOSTAT 98 |
ENDA/IEPE and ESMAP |
OLADE 80-97 |
Other national |
Undefined |
||
FwCons |
32 |
8 |
10 |
14 |
36 |
100 |
ChCons |
32 |
8 |
10 |
17 |
34 |
100 |
32 |
8 |
10 |
15 |
35 |
100 |
The WETT99 best estimates should be considered as historical reference. In fact, most of FAOSTAT 98 figures were replaced in recent years as a result of new official figures or of improved estimation procedures. Similarly, the time series of OLADE 80–97 show considerable differences in respect of the new OLADE 90–02 time series. ENDA/IEPE and ESMAP figures have not changed, since they refer to specific country studies or surveys, but they are all quite old, referring mainly to the 1970s and 1980s or early 1990s at the latest. The source “other national” is more heterogeneous and in several countries recent statistics provided more up-to-date information, compared with the ones used for WETT99. In addition, many country studies have produced new estimates.
Consequently, new “best estimates” would differ significantly from WETT99 data.
The primary source “country reports” includes all data contained in the thematic studies on wood energy statistics carried out by national experts in the framework of the FAO/EC Partnership Programme on Sustainable Forest Management or in FAO field projects on wood energy. As a result of the studies completed from 2000 to 2004, new estimates of fuelwood and charcoal production and consumption were produced for 39 countries. In general, these reports provide new estimates or, more frequently, the best and more recent “blend” of existing national and sub-national level data. The important contribution of these studies is the possibility to review critically and integrate forestry and energy information that is rarely accessible from outside the countries. In view of these features, country reports’ statistics have considerable weight in the evaluation of statistics from other sources.
2 The difficulty of identifying forest and non-forest supply sources and assessing their sustainability should also be considered but will not be discussed here because it is beyond the scope of the present activity. However, it should always be remembered that sustainable resource management remains the main aim when working with international statistics. It is a fact that adequate knowledge is an essential requisite to sustainable resource management and to the formulation of sound policies.
3 Reports which are not published through conventional publishing channels –or in bood, which are not usually included in the classic citation analysis tools
