“Level 1” Statistical Forest Inventory on the Landscape-Ecological Basis
Summary
In the whole Soviet Union, and in Georgia, in particular, forest inventory and management planning were based on the age class method with obligatory visits to and descriptions of each cruising parcel, regardless of the functions and designation of forests. Most parcels were described by the visual method which added to the bias of the data. International experience refers this method to labour-consuming and, hence, costly practices. Even well-developed strong economies rarely apply it to the whole area of their forests.
When labour-consuming and costly forest inventory is conducted without due regard to forest designation, the data obtained are not used or under-used, and such an approach does not meet the needs of a market economy.
At the same time, it should be noted that in forestry, the existing planning practice with respect to prohibitions and restrictions of anthropogenic impact upon forests is based on the single nation-wide regulatory framework regardless of the country's natural geographical complex landscapes.
Forest resources are restored, and environmental damages are precluded through sustainable forest management and its planning on the landscape/ecological basis.
In view of the aforesaid, as well as of the intention to ensure compatibility with the forest inventory and planning methodologies and trends applied in most countries of the global community, we have developed the proposed methods under the auspices of the Georgian Forest Sector Centre.
The methods are intended for the national general forest inventory of the I level.
The inventory should cover all categories of forests regardless of their designation and ownership.
A parcel is considered to be the primary indivisible unit of account. The developed method is based on the formation of a parcel-wise sample with its subsequent extrapolation to the general population.
Final criteria and parameters are defined in accordance with the identified objectives of the inventory. This provides a basis for the identification of strata into which parcels are integrated by means of interpreting coloured images. Further on, inventory plots are established and used for the overall enumeration assessment of cruising and landscape/ecological indicators - in this way the parcel characteristics are defined, and the variance is equalised by the number of the plots, with average data estimated for the strata. The number of the plots depends on the targeted level of accuracy and probability.
The main peculiarity of the method consists in its landscape basis allowing to sample according to identified landscapes.
The method applies multi-step sampling, including series, typical, and mechanical samples.
Organisational and Technological Scheme of the I Level Forest Inventory on the Landscape/Ecological Basis.
Inventory may cover a region, an administrative district, a leskhoz.
The full forest inventory cycle consists of the following phases:
A- preparatory activities; B - field operations; C - desk review.
A - Preparatory Activities.
1.Forest Inventory.
1.1.Study the object of the work based on literature and maps.
1.2.Analyse the legal framework for the functional and administrative classification of the forests and their boundaries.
1.3.Work with topographical maps, aerial photographs (satellite imagery). Assess their quality.
1.4.Introduce the aerial photographs into the geographical information system (GIS).
1.5.Compile orthophotoplans based on topographical maps or prepare aerial photographs for interpretation. (Define the central plot, demarcate the working area, map the geographical and administrative setting).
1.6.Interpret the aerial photographs, identifying homogeneous forest areas (parcels).
1.7.Define the number of strata, their criteria and parameters.
1.8.Unite homogeneous forest areas (parcels) into strata on a tentative basis drawing upon the signs of the interpretation (stratification).
1.9.Define the optimal sample sizes, the number of forest inventory plots (In the sample).
2.Landscape/Ecological.
2.1.Divide the object into landscape/ecological areas.
2.2.Define the characteristics of the landscapes.
2.3.Define the admissible management load upon the landscape.
2.4.Define the forest capacity within the landscape.
2.5.Define the minimum needs for forest resources in the zone of the planned object.
2.6.Present the final results to and agree them with the local administration, governmental and non-governmental organisations, forest loggers, and local people.
2.7.Hold a technical meeting to discuss the final results of the I phase and issue guidelines and regulations for the following phases.
3.B - Field Operations.
3.1.Establish sample plots and circular plots with permanent radii, and conduct enumeration cruising there.
3.2.Collect data to verify the stratification. Assess the stratification accuracy.
3.3.Assess the achieved accuracy of the forest inventory.
3.4.Establish additional circular plots of permanent radii to achieve the targeted accuracy.
4.C - Desk Review.
4.1.Adjust the tentative stratification. Finalise the stratification.
4.2.Put the mapped inventory data in the computer to produce GIS forest thematic maps.
4.3.Prepare an aggregate table. Put the information from the sample plots, circular plots, and cruising tables in the computer.
4.4.Finalise the assessment of the forest inventory accuracy.
4.5.Compile summarised matrices for the Forest Fund.
4.6.Define the harvests of forest resources on the landscape/ecological basis regardless of the minimum needs for forest resources – Option I.
4.7.Define the harvests of forest resources required to satisfy the minimum needs, and adjust the landscape/ecological basis guidelines.- Option II.
4.8.Present the two options to and agree them with the local administration, governmental and non-governmental organisations, forest loggers, and local people.
4.9.Hold a technical meeting to approve the option of forest resource harvests.
4.10.Approve the plan. Environmental review.
4.11.Monitor the quantitative and qualitative status of the forests with due regard to the forest capacity, management activities, and natural processes.
The Methodology Focus.
1.Landscape/ecological carcass (Basis).
The existing planning practice with respect to prohibitions and restrictions of anthropogenic impact upon forests is based on the single nation-wide regulatory framework regardless of the country's natural geographical complex landscapes.
Goals and objectives of the landscape/ecological basis are to define:
I.the admissible management (anthropogenic) load upon the landscape to safeguard the environmental security.
II.the forest capacity in this landscape.
The admissible load is defined at two levels of the landscape hierarchy, at the species level, and at the sanakhi (sub-area demarcated with natural boundaries) level.
Under flatland conditions, environmental security may be well safeguarded with forest management at the landscape level alone. However, in mountainous conditions, two-level regulation is required for sustainable forest management and forest resource harvesting because of highly mosaic natural geographical complexes.]
2. Basic statistical formulae applied in the methodology.
The tentative number of inventory plots within strata:
where: – number of inventory plots (surveyed parcels)
- average growing stock variance per 1 ha/m3
– total number of parcels in a stratum
– targeted accuracy (%) in the absolute value
– significance (0.68-1, 0.95-1.96)
where: - average growing stock range 1 ha/m3
k – coefficient = 0.042
The final number of inventory plots:
The achieved accuracy:
where: - average error
n– sample – the number of surveyed parcels
N – general population – the total number of parcels
where: P- relative error in %;
- average rate.
3. The authors of the methodology defined cruising and landscape/ecological indicators for both the I and the II levels of forest inventory which are reflected in the cruising table.
The cruising table includes as many indicators as possible. The substance and completion of the cruising table depend on the purposes of a forest inventory.
Guidelines were developed to fill the cruising table, including account criteria and parameters (see the cruising table).
The cruising table is filled with the data obtained through the establishment of sample plots. To collect information from sample plots, operating rules were developed for the establishment of both rectangular and circular plots. The rules provide a detailed description of the action sequence for the information collection in the forest, and its desk processing.
The area of sample plots ranges from 2,000 m2 to 5,000 m2 , and depends on the stand stocking. Trees with DBHs of 8 cm or more are counted and measured on the entire area of a plot, and the rest of the plants are assessed within an area of 80 m2 .
Operating inventory rules were developed for butt stands. Butt stands had resulted from tree felling at a height of 2 - 5 m from the butts.
Consultant /O. Shengelia/
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Compartment # Lesnichestvo CRUISING TABLE
1 / Parcel # / Area
HA / Land category / Regime / ОЗУ / Slope / ВНУМ / Erosion / 2 / Planned activity / Targeted species
Exposure / Steep / Species / Degree / I / % / Tech. map
# / II / Tech. map
# / III / Tech. map
#
3 / Dominant species / Site class / Forest type / Site conditions / Felling year / 4 / Debris m3 / Dead trees m3 / Management activity
Overall / Merchantable
Storey / Composition / A
years / H
m / D
cm / Merchantability class / Provenance / Stocking / G / Growing stock m3/ha / Storey / Composition / A
years / H
m / D
cm / Merchantability class / Provenance / Stocking / G / Growing stock m3/ha
Coefficient / Species / Coefficient / Species
10 / 10
10 / 10
10 / 10
10 / 10
10 / 10
10 / 10
10 / 10
Young growth
31 / # thou. pieces / H,m / A,
years / Coeff. / Species / Coeff. / Species / Coeff. / Species / Status assessment / Undergrowth
32 / Spacing / % cover / Species / Species / Species / H, m
Soil characteristics
24 / Soil group / Mechanical composition / Moisture / Soddiness / Soil capacity / % rock exposure / Coordinates
35 / Longitude / Latitude / 36 / Landscape type / Sanakhi index
Economic assessment
37 / Commercial / Recreational / Protective / Landscape/ ecological carcass
38 / Zone / Geodynamical processes / Location / Anthropogenic transfor
39 / Type / Degree / Physical
accessibil.
28 / Accessib. category / Vehicle type / Distance to the road
Assessment
40 / Potential catastrophic processes / Plant species diversity
41 / # of species / Fauna habitats
42 / Nests / Hollows / Formicaries / Dens
Type / Probability / Fire danger class / Damage class / Total / Relict / Endemic / Valuable / Red Books
Phyto-mass
43 / Crown closure / Phytomass / Green mass / Dynamics
44 / Last stage of the development / Composition by # of trees 45 / Coeff. / Species / Coeff. / Species / Coeff. / Species / Coeff. / Species
m3 / ton / m3 / ton / Composition / Stocking / Gr. stock / Site class
Non-wood reources 16 / Category / Type / Age / H,
m / Measurement unit / Yield / Grass cover
14 / Category / Type / % cover / Type / % cover / Type / % cover
Stand damage
12 / Type / Year / Species / Pests and diseases / Source / Recreat. assessment
21 / Scenary type / Assessment class / Degree assessment / Degradation degree / Minor archit. forms
Species / Degree / Species / Degree / Aesthetical / Sanitary / Sustainable / Passable / Visible
Management activities implementation15 / Code / Year / Species / Gr. stock / Implem. review / Assessment / Reason for unsatisfactory implement / Area / Characteristivs of agr. lands
17 / User / Quality / Type / Status / Sodding / Yield t/ha
Species / %
Orchards plantations
22 / Orchard category / Establishment year / Species / Spacing / # of trees / Yield
t/ha / Previous inventory 27 / # parcels / Arae / Land category / Composition / Dominant species / Main species / Stocking / Planned activity
Between rows / Within rows / Total / Including fruit-bearing
Data on additional о models
# / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / № / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8
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Final Report
As per the CSI-7/2 contract, the main objective of the verification project is to revise the statistical aspects of the I level forest inventory on the landscape and ecological basis.
The initial draft methodology was developed in 2001 under the CSI-7/nd-2 contract.
Upon consultation with international experts and review of the data to be obtained under a pilot in the Onsky leskhoz in 2003, the draft will be finalised to produce a model of improved forest inventory of the I level by the statistical method on the landscape and ecological basis.
In 2002, the following activities were implemented:
1. Together with a local consultant on the landscape/ecological carcass, a single work plan was developed.
2. In the Onsky leskhoz, field forest planning and inventory operations were inspected, with consultations thereon.
The Onsky leskhoz field operations were performed by 13 cruisers and one team leader. I inspected the work of 9 cruisers. The specialists were equipped with vehicles, and metering devices (except for GPSs). The inspection covered at random 9 inventory sample plots for control enumeration account.
Revealed errors, inaccuracies, recommendations were reviewed at a meeting held by the Centre Director, and managers of the Gruzlesproyekt were instructed to inspect field operations on their part.
The identified key inefficiency was that field operations were conducted without prior stratification by aerial photography which is a deviation from the developed initial draft methodology.
A detailed description of the detected errors and inefficiencies is presented in the inspection record in the interim report. The errors and inaccuracies are primarily accounted for by the out-dated mentality of the cruisers who deem that the main things about inventory indicators are the marking of sample plots with beautiful ground signs (poles, pickets, stakes), the definition of cruising diameters whereas such indicators as undergrowth, young growth, cover, soil and other landscape/ecological indicators are only secondary in significance.
The inspection record contains specific instructions to rectify the detected mistakes.
3. Following the inspection of the field operations, I - together with the LEC Consultant and Co-ordinator delivered a training in forest inventory. The training for 10 cruisers included the establishment of two inventory sample plots where the enumeration account was focused on the errors detected under the inspection and on the work with new measuring devices. The training took into account the changes to the initial draft methodology.
4. A field survey of the identified landscape and cruising areas was conducted together with the LEC Consultant and resulted into an agreed final format of the cruising table for the Onsky leskhoz. The earlier developed cruising table format was modified as regards its lay-out cells 16, 36, 40, 41, 43. The modification was based on up-dated criteria of bio- and phytodiversity.
5. Together with the LEC Consultant (N. Beruchashvili), we examined cruising areas identified by the cruisers, and landscape areas identified by the LEC team in the Onsky leskhoz along the survey lines for purposes of making them compatible. Following an exchange of opinions and disputes, a hierarchy of the landscape/ecological carcass was adopted.
In forestry, the least unit of the landscape/ecological carcass is a “sanakhi” (a sub-area demarcated by natural boundaries) with their combination constituting a “landscape type”.
The assumption that “sanakhis” are the least units of the landscape/ecological carcass and their aggregation into “landscape types” allow to define: 1. the degree of admissible management load on a landscape safeguarding the environmental security; and 2. forest capacity.
6. Comments and recommendations to be integrated into the drafted methodology were collected on a permanent basis the whole year through in close co-operation with specialists from the Gruzlesproyekt and other lead foresters. Upon agreement with the Inventory Co-ordinator, the methodology was appropriately amended.
One of the latest proposals from the Gruzlesproyekt was a request to draft provisional operating rules for butt crop inventory. Together with the Inventory Co-ordinator, I developed such rules which were then approved by the Forestry Department.
Over the year 2002, 30 changes and amendments were made to improve the draft methodology.
7. To design a statistical model of the I level forest inventory, consultations were held with a statistics expert.
The consultations helped to define a formula for calculating the tentative number of inventory plots within strata.
where: – number of inventory plots (surveyed parcels)
- variance of the average growing stock per 1 ha/m3
– total number of parcels in a stratum
– targeted accuracy (%) in the absolute value
– significance (0.68-1, 0.95-1.96)
where: - range of the average growing stock 1 ha/m3
k – coefficient = 0.042
The final number of inventory plots is derived using the following formula:
The achieved accuracy of an inventory is estimated by the following formula:
where: - average error
n– sample – the number of surveyed parcels
N – general population – the total number of parcels
where: P- relative error in %;
- average rate.
The drafted methodology applies a multi-level statistical sampling.
8.The accuracy of the key cruising indicators were assessed by the statistical method. The analysis was based on comparing the final data obtained by the statistical method (the I level) with the final data obtained through detailed inventory (the II level). The comparison was effected in the Sorskoye lesnichestvo (forest range) of the Onsky leskhoz. The comparison of the collected data shows that it is impossible to get the information level required for sustainable forest management using the sampling-statistical method without the parcel-wise division in Georgia's mountainous forests with their intricate landscape mosaic.
The sampling method based on the parcel-wise division with parcel stratification and the use of the landscape/ecological carcass is acceptable for the I level forest inventory.
The said method allows to obtain quantitative and qualitative forest information with a targeted accuracy, to estimate optimal harvests of forest resources, to define a strategy of sustainable forest management at the rayon, regional, and national levels.
9.Over the year 2002, I had consultations with specialists from the Gruzlesproyekt on a daily basis.
The drafted methodology includes such a work phase as stratification. The stratification includes interpretation of aerial photographs, and classification of cruising parcels into strata.
This work should be done by a group of interpretation experts consisting of specialists who have been trained and tested in image interpretation.
The Gruzlesproyekt did not fully implemented this activity which may negatively affect the results of the pilot in future.
In view of the noted above, the Gruzlesproyekt should set up an aerial photograph interpretation group as soon as possible, and provide training and testing for its members.
To successfully complete the drafting of the improved methodology in 2003, there is a need to draw upon services of international consultants, review the completed desk studies in the Onsky leskhoz, finalise the draft methodology, and extend it to foresters, geographers, ecologists and other specialists, and hold a presentation of the developed methodology.
Consultant /O. Shengelia/
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