Report from Jerry Vanclay, as distributed by e-mail for IUFRO S4.02.03 newsletter

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Introduction

We did not debate a definition of "sustainability", but accepted a general understanding that

it implies the ability of a production system to provide for the present without impairing future productivity and without limiting future options.

Sustainability is not absolute, but is an ideal towards which we should strive as circumstances permit. It involves compromise between ecological, economic and social objectives, all of which are equally important. Over-zealous ecological criteria for industrial forest plantations may be detrimental if they result in the conversion of forest land to other uses with higher environmental impacts.

Guidelines for assessments

It is important to recognise that the system of data handling may be more important then the individual items of data. Assessment involves collecting, collating, storing and synthesizing data, and informing all interested parties of the implications. It is essential to devise a coherent system to accommodate these aspects with the resources available. The set of criteria needed to monitor sustainability should be determined, suitable indicators to assess these criteria should be determined, and appropriate procedures should be instituted.

Commence with what can be effectively assessed now, but plan for the future by setting up a framework for what should come later. Establish standards, document them, and ensure that they are maintained. Do not sacrifice quality for quantity of data.

Concepts of sustainability include elements of ecological, economic and social sustainability. Traditional permanent sample plots may play an important role in monitoring ecological aspects of sustainability. Nested systems of inventory are efficient and flexible, and an appropriate system for monitoring sustainability may include remote sensing of forest areas, static inventory (i.e. temporary plots) to record current status, dynamic inventory (permanent plots) to measure change, and elite monitoring plots for detailed measurement. All monitoring systems should require that plot locations are accurately determined, that all details are carefully recorded, and that standards are maintained. This requires training and supervision, commitment and continuity. It also requires technology that is appropriate, robust and affordable. Care is necessary to avoid instrument and personal bias. Objective measurements are preferable to visual assessments, provided that instruments are appropriate and that training in their use had been provided. Context will determine what should be measured, but it may be appropriate to include volumes harvested; standing volumes, phytomass and leaf areas; growth rates; and soil properties such as litter, organic content, erosion and compaction.

Since it is impossible to measure everything everywhere, off-site ecological impacts may best be assessed through selected indicators that integrate many factors. For example, it may be appropriate to monitor stream flow (volume and variability), turbidity, and biological indicators such as algae and amphibians (composition and numbers). Some plants, especially those in the understorey, may also serve as indicators of sustainable practice and may give an early warning of emerging problems. However, note that species distributions may exhibit spatial and temporal changes even where there is no human intervention. Faunal indicators may be best monitored seasonally at local watering holes or feeding spots (e.g. monitor birds in fig trees when few other trees fruit).

Economic and social aspects of sustainability may be less amenable to plot-based monitoring, but should not be omitted from assessments of sustainability. Since assessment procedures should be context-dependent, only general guidelines can be given. Sustainability is a multi-faceted concept, so increased participation by many disciplines should offer a stronger basis for both better management of forests and better monitoring of sustainability. Monitoring involves a cycle: define goals, choose suitable indicators, devise assessment procedures, conduct assessment, evaluate results, present findings, refine goals, and repeat the cycle. This cycle should be iterative, but must progress, not merely re-invent. Progress requires that we build both on our own experience, and on the findings of others presented in the literature.

Finally, the following points may be useful as the beginnings of a checklist:

1. What is the purpose of assessing sustainability of forest management (e.g. operations, planning, policy, international agreements)?

2. What scale is relevant (e.g. compartment, forest, watershed, nation, global)?

3. What actors are involved (e.g. communities, government, corporations)?

4. What are relevant sustainability goals to be discussed among actors (consider economics e.g. yields, revenue; ecology e.g. biodiversity, water quality; social aspects e.g. tenure)

5. Assess sustainability goals and highlight information requirements in the light of system behaviour and use, with special consideration of the likely timing and location of potential problems (e.g. anticipated or unpredictable, minor or catastrophic, single event or continuing trend, localized or widespread), and the anticipated nature of observable problems.

6. Define indicators of sustainability and consider suitable measurement scales (e.g. present/absent, qualitative, quantitative).

7. Define when, where and how to measure these indicators, giving special attention to the sampling scheme (e.g. purposive, systematic, stratified random).

8. Select and apply a suitable assessment methodology (e.g. permanent sample plots, environmental impact assessment, forest resource accounting, cost-benefit analysis).

9. Reconsider and, if necessary, revise the entire procedure from step 1 in the light of interim results of the assessment.

What to measure on permanent plots?

• Assess future productivity: Monitor harvests, growth rates, crown condition (e.g. crown density and foliar nutrients), and selected soil properties (e.g. compaction, erosion).

• Assess implications for non-target species: Monitor population and vigor of selected indicator species (e.g. ground flora within plot, fauna at convenient feeding or watering sites nearby).

• Assess off-site impacts: Monitor quality and quantity of surface and ground water (e.g. with indiactor species such as algae and amphibians).

• Are existing plots suitable? Are they the right size and shape? Will their location, history and management lead to a biased incication of sustainability?

• Can experiments be used to gauge sustainability? Will a small trial give a realistic indication of routine operations? What should be the minimum experiental area, and what should be the minimum area for measurement?

• For new plots: How many, and what size? Where to put them for early warning systems, for mapping, or for quantification?

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