Section 4. Carbon Stock Measurement Methods 4.2. Design of field sampling framework for carbon stock inventory USAID LEAF Regional Climate Change Curriculum Development Module: Carbon Measurement and Monitoring (CMM) Name Affiliation Name Affiliation Deborah Lawrence, Co-lead University of Virginia Megan McGroddy, Co-lead University of Virginia Bui The Doi, Co-lead Vietnam Forestry University Ahmad Ainuddin Nuruddin Universiti Putra Malaysia Prasit Wang, Co-lead Chiang Mai University, Thailand Mohd Nizam Said Universiti Kebangsaan Malaysia Sapit Diloksumpun Kasetsart University, Thailand Pimonrat Tiansawat Chiang Mai University, Thailand Pasuta Sunthornhao Kasetsart University, Thailand Panitnard Tunjai Chiang Mai University, Thailand Wathinee Suanpaga Kasetsart University, Thailand Lawong Balun University of Papua New Guinea Jessada Phattralerphong Kasetsart University, Thailand Mex Memisang Peki PNG University of Technology Pham Minh Toai Vietnam Forestry University Kim Soben Royal University of Agriculture, Cambodia Nguyen The Dzung Vietnam Forestry University Pheng Sokline Royal University of Phnom Penh, Cambodia Nguyen Hai Hoa Vietnam Forestry University Seak Sophat Royal University of Phnom Penh, Cambodia Le Xuan Truong Vietnam Forestry University Choeun Kimseng Royal University of Phnom Penh, Cambodia Phan Thi Quynh Nga Vinh University, Vietnam Rajendra Shrestha Asian Institute of Technology, Thailand Erin Swails Winrock International Ismail Parlan FRIM Malaysia Sarah Walker Winrock International Nur Hajar Zamah Shari FRIM Malaysia Sandra Brown Winrock International Samsudin Musa FRIM Malaysia Karen Vandecar US Forest Service Ly Thi Minh Hai USAID LEAF Vietnam Geoffrey Blate US Forest Service David Ganz USAID LEAF Bangkok Chi Pham USAID LEAF Bangkok I II III OVERVIEW: CLIMATE CHANGE AND FOREST CARBON 1.1 Overview: Tropical Forests and Climate Change 1.2 Tropical forests, the global carbon cycle and climate change 1.3 Role of forest carbon and forests in global climate negotiations 1.4 Theoretical and practical challenges for forest-based climate mitigation FOREST CARBON STOCKS AND CHANGE 2.1 Overview of forest carbon pools (stocks) 2.2 Land use, land use change, and forestry (LULUCF) and CO2 emissions and sequestration 2.3 Overview of Forest Carbon Measurement and Monitoring 2.4 IPCC approach for carbon measurement and monitoring 2.5 Reference levels – Monitoring against a baseline (forest area, forest emissions) 2.6 Establishing Lam Dong’s Reference Level for Provincial REDD+ Action Plan : A Case Study CARBON MEASUREMENT AND MONITORING DESIGN 3.1 IV V Considerations in developing a monitoring system CARBON STOCK MEASUREMENT METHODS 4.1 Forest Carbon Measurement and Monitoring 4.2 Design of field sampling framework for carbon stock inventory 4.3 Plot Design for Carbon Stock Inventory 4.4 Forest Carbon Field Measurement Methods 4.5 Carbon Stock Calculations and Available Tools 4.6 Creating Activity Data and Emission Factors 4.7 Carbon Emission from Selective Logging 4.8 Monitoring non-CO2 GHGs NATIONAL SCALE MONITORING SYSTEMS Lecture (50 minutes) Why sampling is important Major sampling approach Stratification Examples of stratification approaches used in forests Class activity (15 minutes) Homework At the end of this session, learners will be able to: Explain why sampling is necessary Distinguish among random, stratified, and systematic sampling, and know where each is appropriate Determine the advantages and drawbacks of different sampling schemes: Often it is impractical to examine an entire population Instead, we select a sample from our population of interest and, on the basis of this sample, information about the entire population will be inferred It is extremely unlikely that we would have the time and resources needed to measure the entire carbon stock in a forest or landscape Instead we select a sample from an area of interest, on the basis of this sample, we can infer information about the entire area Conclusions about an entire population will be drawn based on the sample information through statistical inference 1. Measure carbon stocks in sampled areas 2. Assume sampled carbon stocks represent a reasonable estimate of population carbon stocks, 3. Multiply measured carbon per unit area by entire area of interest to calculate the carbon stocks 4. Use the variation among your plot values to estimate uncertainty The sample must provide an accurate picture of the population from which it is drawn The sample should be random; each individual in the population should have an equal chance of being selected Different sampling schemes can be used: i. Simple random sampling ii. Systematic sampling iii. Stratified sampling iv. Cluster sampling i Different sampling schemes can be used: i. Simple random sampling ii. Systematic sampling iii. Stratified sampling iv. Cluster sampling i ii Different sampling schemes can be used: i. Simple random sampling ii. Systematic sampling iii. Stratified sampling iv. Cluster sampling i ii iii Different sampling schemes can be used: i. Simple random sampling ii. Systematic sampling iii. Stratified sampling iv. Cluster sampling i ii iv iii Sampling units are independently selected one at a time until the desired sample size is achieved Each study unit in the finite population has an equal chance of being included in sample without any bias http://www.youtube.com/watch?v=yx5KZi5QArQ A random sample Disadvantages: Errors in sampling Time and labor requirements Advantages: Representativeness and freedom from bias Ease of sampling and analysis Distributes the sample evenly over the entire population Bias may arise if there is some type of periodic variation in carbon stocks, but such patterns are rare http://www.youtube.com/watch?v=QFoisfSZs8I Disadvantages: Bias in overestimating the actual standard error Less flexible to increase or decrease the sampling size Not applicable for fragmented strata Advantages: Spatially well distributed Small standard errors Long history of use Involves grouping the population of interest into strata to estimate characteristics of each stratum and to improve the precision of an estimate for entire population http://www.youtube.com/watch?v=sYRUYJYOpG0 Disadvantages: Yields large standard error if the sample size selected is not appropriate Not effective if all variables are equally important Advantages: Allows specifying the sample size within each stratum Allows for different sampling design for each stratum Involves a grouping of the spatial units or objects sampled All observations in the selected clusters are included in the sample http://www.youtube.com/watch?v=QOxXy-I6ogs Primary Sampling Unit (PSU) Advantages Can reduce the time and expense of sampling by reducing travel distance Disadvantages Secondary Sampling Unit (SSU) - cluster Can yield higher sampling error Can be difficult to select representative clusters i. Divide class in 4 groups (pick students randomly or systematically) ii. Randomly assign each group one of the sampling techniques and a map of land cover either national or regional iii. Each group should meet outside of class and decide on how to locate sampling plots to estimate per cent of each major land cover class based on the technique they were assigned. Next class they should be prepared to present their maps with sampling plots marked on them Allows for measuring and monitoring areas where changes are likely to occur Reduces sampling effort while maintaining accuracy and precision in carbon stocks estimates Allows for wise spending of the resources By threat of deforestation Use historical evidence to identify critical factors of deforestation Create potential for deforestation map Identify areas with high probability of deforestation By forest type Use existing maps of vegetation types Use existing forest inventory By accessibility Define accessibility criteria (e.g. 5 km accessibility to main roads) Use spatial analysis to model accessibility Stratifying by carbon stock reduces the sampling effort required to achieve targeted precision level Develop initial stratification plan Land use Vegetation Slope Drainage Proximity to settlement Collect preliminary data (~10 plots per stratum) 4. Create deforestation threat map 3. Identify areas with high suitability for deforestation 2. Identify key factors impacting historical deforestation patterns 1. Use spatially explicit land use change model Sampling is very important in forest inventory in order to estimate information about an entire population There are a number of sampling techniques but stratified sampling is most commonly used in forest carbon inventory Forest types (or Carbon stocks) and threat of deforestation/ degradation are two main factors that are used to stratify the study area. Asner, G.P. 2009. Tropical forest carbon assessment: integrating satellite and airborne mapping Approaches. Environ. Res. Lett. 4 034009 Czaplewski, R., R. McRoberts and E. Tomppo. 2004. Sample designs. FAO-IUFRO National Forest Assessments Knowledge reference http://www.fao.org/forestry/7367/en/ Maniatis, D. and D. Mollicone. 2010. Options for sampling and stratification for national forest inventories to implement REDD+ under the UNFCCC Carbon Balance and Management, 5:9 doi:10.1186/1750-0680-5-9