Litter Stock Change Method

The litter stock change method estimates the stock of litter biomass at a given time. The litter stock could be measured at two points a year apart or even 5 years apart. The method involves collection and weighing of the litter in the selected sample plot and the following steps:

Step 1: Select and stratify the land-use category or project activity for which the litter biomass has to be estimated (Chapter 10). Step 2: Decide on the sampling method, including sample size, number of plots, and sampling design used for estimating shrub biomass (usually 8-10 shrub plots of 5 x 5 m each). Step 3: Assemble the material required for measurement, namely:

° A spring balance, measuring tape, pegs and ropes to mark the four corners, a heavy-duty cutting tool for cutting wood and a knife for cutting litter

Step 4: Mark the four corners of each shrub plot and also record the GPS readings.

Step 5: Sweep and collect all the litter from the sample shrub plots and separate it into woody and non-woody litter. In collecting litter near the boundary, include any piece of litter so long as at least half its length is within the sample plot.

Step 6: Estimate the fresh weight of the litter in the field for each sample plot.

Step 7: Estimate the dry weight by collecting a sample of about 0.5 kg and drying it to a constant weight in an oven. Step 8 Extrapolate the sample plot value of dry litter to per hectare stock of the litter.

This method estimates the carbon stock in the litter pool at a given point in time; changes in the stock can be estimated by repeating the measurements after 1 year.

12.2.2.1 Merits and Demerits of Measuring Stock Change

Merits: Stock change is a simple and cost-effective method requiring minimal field visits, measurements and materials. Demerits: The litter biomass may be removed for fuelwood or other purposes or lost by being blown away, losses that are not captured by this method. Estimation of litter using the annual litter production method is complex and expensive, and it is important for project managers to choose between measuring litter production and monitoring litter stock changes.

12.3 Long-Term Monitoring of Deadwood and Litter

Deadwood and litter in land-use systems such as forests and plantations accumulate over long periods if the biomass is not removed. These two pools could be monitored by adopting the "Stock-Difference" approach and the permanent plot method.

Deadwood Select the permanent sample plots marked for long-term monitoring of above-ground tree biomass (Chapter 10) and adopt the method described for standing and fallen deadwood in Section 12.1 for long-term monitoring of changes in stocks of deadwood.

Litter Select the permanent sample plots marked for shrubs for long-term monitoring of litter using "Stock-Difference" approach. Adopt the method described in Section 12.2.2 for long-term monitoring of litter stock changes.

12.4 Conclusions

Dead organic matter consists of standing and fallen deadwood and litter biomass. These pools are likely to be significant for forests and plantations but not for other land-use categories or project activities. Both the deadwood pools can be measured easily by using the methods described in this chapter, simultaneously with measurement of above-ground biomass pool (Chapter 10), with very little additional cost or human effort. Similarly litter biomass could be estimated using the stock change measurement method, along with above-ground biomass (Chapter 10), with very little additional cost or human effort. However, estimating annual litter production is complex and time consuming, and expert judgment is needed in deciding whether dead organic matter should be measured, especially since it accounts for only about 10% of the total carbon stocks in forests.

Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

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