Field Guide for
Contents
1. Dead trees and palm trees Measure the DBH of dead trees and palms as you would other live trees but only if the measurement protocol states that these trees are to be included 42 Field Guide for Forest Biomass and Carbon Estimation What s in Chapter 5 Often the best way to learn new concepts is by example In this chapter you will be provided with an example data set that includes tree diameter measurements as explained in Chapter 4 obtained within a typical forest sample plot as explained in Chapter 3 A series of exercises are used to demonstrate how diameter measurements can be used to compute tree level plot level and per hectare estimates of aboveground biomass and carbon You will also learn how to calculate estimates of carbon dioxide emissions to the atmosphere for an area of forest that has been cleared Carbon Estimation BIOHASS Biomass and Es Estimating aboveground biomass in the field The most direct approach to estimating the aboveground biomass of a tree involves a number of steps including 1 harvesting the tree 2 cutting the tree including the leaves branches and stem into small more manageable pieces 3 oven drying the pieces and 4 carefully weighing the pieces once they are thoroughly dried and all water has been removed Although very ac curate this method is also very time consuming expensive and destructive Hence it is not a practical approach to obtai2. explained in Box A The AGB values calculated for each tree can be added together to obtain an es timate of the total AGB for the sample plot In this example the total AGB for the plot is estimated to be 24 5 metric tons see Table 5 1 Typically AGB is reported on a per hectare basis Figure 5 3 illustrates the spa tial relationship between the 40 m x 40 m sample plot and a one hectare parcel The formula for converting from a per plot estimate of AGB in metric tons to a per hectare estimate in metric tons per hectare can be calculated as AGB A A AGB where AGB is the estimate of aboveground biomass in metric tons per hectare A is the area of one hectare in square meters A is the area of the plot in square meters and AGB is the plot level estimate of aboveground biomass in metric tons Thus in this example where the area of one hectare is 10 000 m the area of the plot is 40 m x 40 m or 1600 m and the above ground live dry biomass in the plot is approximately 24 5 metric tons the per hectare estimate of biomass is calculated as AGB 10 000 40 40 24 5 AGB 10 000 1600 24 5 AGB 6 25 24 5 AGB 153 13 metric tons hectare 48 Field Guide for Forest Biomass and Carbon Estimation one hectare parcel The one hectare parcel is 6 25 times larger than the 40 m x 40 m plot Box C Carbon dioxide emissions calculation for an area deforested The amount of carbon dioxide CO
3. Field Guide for Forest Biomass and Carbon Estimation p 2 a c Y EA E a Version 0 e Purpose This field guide provides an introduction to the basic tools and techniques used in obtaining ground based estimates of aboveground forest biomass and carbon It was written for a general audience emphasizing fundamental skills and real world examples A modular approach was taken such that additional topics chapters could be added as desired Specifically Version 1 0 of this field guide e Explains the basics of GPS and GPS navigation e Describes how to establish sample plots used in obtaining forest measure ments e Explains how to take tree diameter measurements used in forest biomass estimation e Demonstrates how to compute estimates of forest carbon storage from sample plot data e Serves as a reference for both field and office use e Incorporates graphical illustrations for multi lingual users e Is not a substitute for formal instruction and hands on training Produced by Woods Hole Research Center Dr Wayne Walker Version 1 0 June 2011 Suggested citation Walker W A Baccini M Nepstad N Horning D Knight E Braun and A Bausch 2011 Field Guide for Forest Biomass and Carbon Estimation Version 1 0 Woods Hole Research Center Falmouth Massachusetts USA Funding provided by Gordon and Betty Moore Foundation Google org The David and Lucile Packard Foundation Norwegian Agency for D
4. Figure 3 8 It is the job of the navigator to keep the tapelayer on a straight path toward the plot cor ner In areas with dense undergrowth it may be necessary to have a line cutter a team member skilled in the use of a ma chete walk ahead of the tapelayer clearing a narrow path along which the tapelayer can walk more easily Figure 3 9 Note that the clearing of un dergrowth should be done only where absolutely necessary As the tapelayer walks care must be taken to ensure that the tape is kept as straight horizontal and taut as possible If obstacles such as trees or boulders are encountered along the path the line should be off set as shown in Figure 3 5 Once the tapelayer reaches the location of the first plot corner which is 28 m away from the center point of a 40 m x 40 m plot Figure 3 1 the corner point is marked with a stake similar to that used at the plot center Figure 3 2 The tape is then pulled taut and wrapped securely around the base of the corner stake Figure 3 10 At this stage it is critical that both team mem bers double check the position of the line confirming that the tape is straight horizontal and taut before moving on If the line is observed to meander the tape must be reeled in so that the line can be laid properly Figure 3 8 Zhe tapelayer keeps the tape low and taut while walking a straight line After the first plot corner is located and staked team mem
5. Wet tropical forest Dry tropical forest Aboveground Live Dry Biomass t 0 50 100 10 Diameter at Breast Height cm Figure 5 1 Zxampies of allometric equations developed by Chave et al 2005 for use with groups of tropical forest tree species The equations relate measurements of diameter at breast height DBA to estimates of aboveground live dry biomass AGB For example a moist tropical forest tree species with a DBH of 100 cm would have an AGB of 13 3 t Similarly a wet tropical forest tree species with a DBH of 100 cm would have an AGB of 7 9 t Understanding biomass and carbon calculations In the remainder of this chapter an example data set is used to illustrate how DBH measurements see Chapter 4 obtained within a typical sample plot see Chapter 3 can be used together with allometric equations such as those shown in Figure 5 1 to compute tree level plot level and per hectare estimates of AGB and carbon The data set includes DBH measurements taken from 28 tropical moist forest trees found within a 40 m x 40 m sample plot Ihe DBH measure ments for all 28 trees are listed in Table 5 1 and the approximate location of each tree within the sample plot is shown in Figure 5 2 Box A describes how the ABG of a single tree e g the first tree listed in Table 5 1 can be calculated using the allometric equation for moist tropical forest trees shown in Figure 5 1 Using this equation it is possible to calculate the AG
6. Avery and H E Burkhart Conservation Research in the African Rain Forests A Techni cal Handbook 2000 L White and A Edwards eds Reports and Articles Tree allometry and improved estimation of carbon stocks and balance in tropical forests 2005 J Chave et al Oecologia Estimating biomass and biomass change of tropical forests A primer 1997 S Brown FAO Forestry Paper 134 Additional Resources Websites Forests Carbon and Climate Woods Hole Research Center www whrc org Center for International Forestry Research www cifor org RealClimate www realclimate org The REDD Desk www theredddesk org United States Forest Service www fs fed us ccrc GPS Garmin GPS www garmin com aboutGPS Garmin GPSmap 60CSx Owner s Manual static garmincdn com pumac GPSMAP60CSx_Own ersManual pdf National Aeronautics and Space Administration gpshome ssc nasa gov National Air and Space Museum www nasm si edu gps United States Geological Survey education usgs gov common lessons gps html Field Equipment Ben Meadows Company www benmeadows com Forestry Suppliers Inc www forestrysuppliers com 52 Field Guide for Forest Biomass and Carbon Estimation Resources Il Equipment List Chapters 2 4 of this field guide describe the various pieces of equipment that are most commonly used to locate establish and measure sample plots intended for the estimation of aboveground forest biomass and carbon What follows is a co
7. Set to your preferred language English French Spanish or Portuguese External Power Lost Only relevant if connected to a computer or other power source Display Allows the appearance of the display to be changed Figure 2 11 Interface Provides settings for connecting to a computer and for data transfer Figure 2 12 Map Allows the user to change how the Map page displays information Figure 2 13 Time Allows the user to set the current time zone and display format Figure 2 14 Units It is very important that the following options are set correctly Figure 2 15 The most commonly used settings are included below e Position Format Allows the user to select the coordinate system Set to decimal degrees hddd ddddd e Map Datum Describes the Earth model that is used to match features on the ground to coordinates on the map Use the default WGS 84 Distance Speed Used to set the units that define distance and GPSmap 60CSx GPSmap 60CSx auc NN Time Format Position Format Time zone Map Datum US Eastern hd WGS 84 UTC Offset Distance Speed 05 hrs Oi Metric Daylight Saving Time Elevation Wert Speed Auto Meters m sec Figure 2 14 Ze Time setup Figure 2 15 Zhe Units setup GPS Navigation speed Set to Metric e Elevation Vert Speed Used to set the units for vertical progress Set to Meters m sec Depth Used to set the units for depth Set to Meters Tem
8. associated parameters be identified and correctly set in the GPS Often this information is specified in the mea surement protocol see Chapter 3 2 Units and precision Ihe appropriate units e g decimal degrees degrees minutes seconds meters or feet and the precision i e number of significant figures of those units must be set in the GPS 8 Field Guide for Forest Biomass and Carbon Estimation 3 Acquisition mode Some GPS units require that the acquisition mode be specified Options typically include 2 D or 3 D navigation In 2 D two dimensional mode elevation the third dimension is not calcu lated by the GPS and only three satellites are needed to fix the position In 3 D three dimensional mode elevation is calculated by the GPS and four satellites are required to fix the position In general 3 D navigation should be used as it provides more accurate position estimates 4 Waypoint list If the GPS unit is capable of storing waypoints e g the locations of sample plots to be visited in the field it is important to confirm that these points are loaded properly onto the unit The Garmin GPSmap 60CSx can store up to 1000 waypoints Nevertheless carrying a paper record of all waypoints as a backup is always advisable 5 Compass configuration If the GPS is equipped with a compass as is the Garmin GPSmap 60CSx it must be properly calibrated and config ured before it can be used The remainder of this cha
9. bers can continue working in pairs to locate the remain ing plot corners i e south east and west When each corner is reached the corner point is staked and the fiberglass tape is pulled taut and wrapped secure ly around the base of the stake Figure 3 10 After the four plot corners have been located Figure 3 1 the next step is to mark the four boundary lines The purpose of marking the boundary lines is to identify which trees are inside the plot and which trees are outside Bound ary lines can be Figure 3 9 Zhe clearing of undergrowth should be done with care and only where absolutely necessary Figure 3 10 Zoe fiberglass tape is wrapped securely around the base of the corner stake marked with fiberglass tapes pieces of cord or lengths of colored flag ging Regardless of what is used care should be taken to ensure that it is obvious to all team members which trees are inside of the plot and which trees are outside Depending on the length of the boundary line and the density of the understory vegetation the ability to see from one plot corner to the next can range from easy to impossible When it is possible to see from one corner to the other the boundary line can be easily marked by tying lengths of flagging to small tree branches along the line Figure 3 11 It is preferable to tie the flagging at eye level x M 2 Figure 3 11 Brightly colored flagging can be used to mark plot
10. hold the end of the tape in place while a diameter measurement is being taken The hook is particularly helpful when measuring large or awkwardly positioned trees However the hook is also quite sharp and care should be taken to avoid accidentally injuring oneself E NE Tree Diameter Measurement 33 Figure 4 5 e a correct and b incorrect way to take a DBH measurement with a diameter tape Figure 4 6 Measuring tree diameter with a caliper 34 Field Guide for Forest Biomass and Carbon Estimation A caliper is another tool that can be used to measure the DBH of trees Figure 4 2 Calipers come in a variety of sizes with large calipers being required to measure the diameters of large trees To measure the DBH of a tree using a caliper the jaws of the caliper are placed on either side of the tree trunk at breast height Figure 4 6 The diameter measurement is then read from the scale to the nearest tenth of a centimeter It is common practice to take two DBH measurements when using a caliper with the second measurement taken perpendicular to the first Ihe two DBH measurements are then averaged to obtain the final diameter value Calipers are generally easier to use than diameter tapes especially for small trees how ever they also tend to produce less accurate measurements especially for large or irregularly shaped trees Large calipers are also more cumbersome to carry than diameter tapes especially in forests wit
11. notes can be added Figure 2 20 To add text to a field move the cursor to the line to be edited using the ROCKER button and press ENTR A small keyboard will appear on the screen Use the ROCKER button to move the cursor to the character to be selected and press ENTR to select the character Continue selecting characters until the entry is complete When finished select OK and then press ENTER to return to the Mark Waypoint page The coordinates of the user s current position appear in the Location field and are used by default when saving the waypoint unless alternative coordinates are entered The bottom of the Mark Waypoint page includes the Avg Map and OK options Descriptions of these options are included below e Avg Used to generate a more accurate waypoint position by averaging multiple position fixes When Avg is highlighted and ENTR is pressed the Average Location page opens and the GPS unit begins to average successive position acquisitions for the current location Figure 2 21 The Measurement Count field includes the number of position fixes that have been averaged remember that the unit is constantly acquiring position fixes each having variable 18 Field Guide for Forest Biomass and Carbon Estimation accuracy As the measurement count increases the position accuracy should begin to improve as marked by a decrease in the Estimated Accuracy value Once an acceptable accuracy is reached select the Save
12. plot By wearing brightly colored clothing and shaking branches as appropriate team members can increase the likelihood of seeing one another through dense undergrowth Notes In general a team of 3 5 people is needed for the efficient set up and sampling of a 40 x 40 m plot A complete list of the equipment items described in this chapter can be found in the Additional Re sources section located at the end of the guide 30 Field Guide for Forest Biomass and Carbon Estimation NE i ps ECN i 5 i 5 vr A JN W EX IL s 5 i i ec a LP x E b As n ih E a Measurement Tree Diameter What s in Chapter 4 Diameter measurements of individual trees form the basis for many of the commonly used approaches to obtaining ground based estimates of aboveground forest biomass and carbon In this chapter you will learn how tree diameter is measured including the tools and techniques used in the field to obtain accurate diameter measurements quickly and efficiently Because trees come in a variety of shapes and sizes you will also learn how to accurately measure the diameter of trees having unusual trunk characteristics Tree Diameter Measurement 7 bed Why measure tree diameter Figure 4 1 Diameter at breast height DBH is measured at 1 3 meters above the ground Exceptions to this rule are discussed later in this chapter One of the most commo
13. storage in forests This field guide written for a general audience emphasizing fundamental skills and real world examples is intended to be one such source of information Using this field guide Version 1 0 of this field guide consists of six chapters spanning a range of topics relevant to the ground based estimation of forest biomass and carbon A modular approach was taken such that further topics chapters could be added as desired First time readers of the guide are encouraged to study the chapters in order as concepts presented in the latter chapters build on those presented in the earlier chapters Chapter 1 this chapter serves as an introduction to the topic of ground based forest biomass and carbon estimation and includes definitions for several frequently used terms Chapter 2 focuses on understanding GPS technology and the role that hand held GPS Introduction devices can play in finding and marking the locations of forest sample plots in the field In Chapter 3 the process of setting up sample plots is explained and in Chapter 4 the types of measurements that are most commonly obtained within sample plots are described Chapter 5 uses an example data set derived from actual forest measurements to illustrate how data collected in the field can be converted to estimates of aboveground forest biomass and carbon Finally Chapter 6 presents a list of additional resources for readers interested to learn more about the specifi
14. 5 m Next the tape is moved away from the original boundary line but parallel to it to avoid the tree The measure ment is then made over the distance that is required to reach the far side of the tree In this example the distance is 2 0 m On the far side of the tree the tape is moved back to the path of the original line and the mea surement is completed The final distance measured in this example is 3 5 m Thus three separate mea surements 4 5 m 2 0 m and 3 5 m are required to span the total distance 10 m interrupted by the tree Figure 3 5 Establishing plot boundaries Square plots are commonly oriented so that the plot corners are in line with the four cardinal directions i e north south east and west Fig ure 3 1 One team member the navigator uses a handheld com pass Figure 3 6 to determine the direction i e azimuth to the first of the four plot corners It does not matter which corner is selected first although north is perhaps most com Figure 3 6 A handheld sighting compass is useful for accurately determining direc tion in the feld mon A second team member the tapelayer then fastens the end of 26 Field Guide for Forest Biomass and Carbon Estimation fastened securely to the base of the center stake one fiberglass tape to the center stake Figure 3 7 and begins walking slow ly in the direction of the plot corner reeling out the tape as he she walks
15. B of any moist tropical forest tree The last column in Table 5 1 includes the AGB estimates for each of the 28 trees found in the example sample plot 44 Field Guide for Forest Biomass and Carbon Estimation DBH AGB Tree cm tons ha 1 0 012 4 283 0 007 0 029 0 007 E 0 016 o8 r ow 9 1 987 0 034 32 2 0 0 628 12 0 012 16 6 0 154 14 0 021 3 16 6 0 013 5 54 6 8 8 1 6 1 54 3 3 237 17 8 0 014 1 00 19 06 20 1 084 0 009 0 025 0 018 6 8 11 5 0 058 42 1 1 719 0 066 27 0 027 0 578 Total Plot AGB 24 536 Table 5 1 Diameter at breast height DBA and aboveground live dry bio mass AGB estimates for 28 moist tropical forest trees within a 40 m x 40 m sample plot Biomass and Carbon Estimation North West East South Figure 5 2 77e locations of 28 tropical moist forest trees within a 40 m x 40 m sample plot The DBH and AGB estimates for each tree in quadrants 1 4 are listed in Table 5 1 Box B describes how AGB estimates for individual trees can be added together to determine the total AGB of a given forested area such as that covered by the sample plot In this example the total AGB of the sample plot is 24 5 metric tons Table 5 1 Box B also illustrates how per plot estimates of AGB can be converted to per hectare estimates which is how area based estimates of AGB are most commonly reported Box C answers the question if all of the tree
16. For example under the Kyoto Protocol a forest is defined as an area of land having a minimum size of 0 5 0 1 hectares tree crown cover of greater than 10 30 and trees having the potential to reach a minimum height of 2 5 meters at maturity Such a broad definition is useful in the context of this field guide because it is generally inclusive of the wide range of forest types and associated biomass densities observed around the world What is biomass The biomass of a tree refers to the weight or mass of its living plant tissue and is generally expressed in units of metric tons t Live biomass can be separated into above ground leaves branches and stems and below ground roots components It is most common to estimate the aboveground live dry biomass AGB of a tree which is the weight of the living aboveground b a iie E 13 25 Other Elements Water mass L20 t Carbon mass 0 60 t Other mass 0 60 t Total Wet Biomass 2 40 t Water mass 0 00 t Carbon mass 0 60 t Other mass 0 60 t Total Dry Biomass 1 20 t Wet Biomass Dry Biomass Figure 1 2 The relative proportion of carbon C Water H20 and other elements e g N B K Ca Mg etc contained in the a wet and b dry biomass of trees Introduction plant tissue after all the water has been removed i e after the leaves branch es and stems have been dried thoroughly often using a special laboratory ove
17. Sed Map j Routing Geocache Marine 5 Time Units Headina 3 Figure 2 8 Ze Main Menu page Figure 2 9 Zhe Setup menu 7 Understanding the Setup options From the Main Menu page use the ROCKER button to select the Setup icon Figure 2 8 Press the ENTR button Several icons will be displayed on a new Setup Menu page Figure 2 9 Use the ROCKER button to select a specific icon Note that not all Setup icons can be viewed on the screen at once i e use the ROCKER button to scroll down to view the remaining icons The most commonly used options are described below System Controls various useful settings for the GPS Figure 2 10 e GPS Under most circumstances set to Normal If battery power is low set to Battery Saver e Battery Type Set to Akaline unless NiMH rechargeable batteries GPS Navigation GPSmap 60CSx NIE G Display Mode Daytime Color Scheme Diamond Nighttime Color Scheme Diamond Backlight Timeout 15 Seconds Backlight Level 1004 GPSmap 60CSx I eo WARS EGNOS Disabled Battery Type Alkaline Text Language English External Power Lost Turn Off Proximity Alarms yoy a 3 USB GARMIN Data Format Not Connected ne Ea Orientation Track Up gt GARHIN Below 200 7 Auto Zoom On Detail Normal Lock On Road On USB Mass Storage u Figure 2 12 The Interface setup Figure 2 13 Zhe Map setup are being used e Text Language
18. apping heat near the surface keeping the temperature of the planet warm enough to support life Figure 1 3 Howev er as the concentration of theses gases in the atmosphere increases the thick ness of the blanket also increases causing temperatures around the world to rise Too much warming can have dramatic effects on the global climate making some areas of the planet unsuitable for plant animal and human existence 4 Field Guide for Forest Biomass and Carbon Estimation The surface of the Earth is heated by the sun Some of the heat is radiated back out toward space Greenhouse gases in the atmosphere including carbon dioxide CO and methane CH trap some of this heat causing warming of the Earth s surface and lower atmosphere Figure 1 3 Greenhouse gases form an insulating layer around the Earth The excessive build up of these gases traps heat leading to warming of the Earths surface Why is there interest in forest carbon Through the process of photosynthesis forests absorb CO from the atmo sphere as they grow storing large amounts of carbon in the biomass of their leaves branches stems and roots while releasing oxygen back to the atmo sphere The forests of tropical America Africa and Asia represent enormous storehouses of carbon yet they are being cleared at a rate of nearly 8 0 million hectares per year In an effort to maintain tropical forests and their vast carbon stores i
19. boundary lines so that it can be easily seen from a distance Trees found on the boundary line are typically con sidered to be inside the plot if the center of the trunk appears to fall either directly on the plot bound ary or somewhere inside it Figure 3 12 Those boundary trees that are determined to be inside the plot should be marked with flag ging tape so that they can be easily identified for later measurement When it is not possible to see from one plot corner to the other three people may be needed to identify and mark the plot boundary With three people working together two team members can take positions at adjacent plot corners while the North East Tree Outside Plot West South Figure 3 12 Care should be taken to determine which trees are inside Sample Plot Layout the plot and which trees are outside third person walks slowly back and forth between them and along the boundary line until he she can see the other team members at the cor ners If possible team members at the corners can use their compasses to help confirm the accuracy of the third member s position along the boundary Once all team members are satisfied that the boundary line has been identified the third person can begin marking the line with flagging tape working first toward one corner and then back toward the other with the goal of making it clear to all which trees are inside and which trees are outside the
20. c topics covered in the guide The sections that follow provide a basic introduction to some of the terms and concepts commonly used in this field guide Terms such as forest biomass and carbon are defined and the fundamental relationships between them are explained What is a forest Forests cover approximately 30 of the planet s total land area or nearly 4 billion hectares and grow in a variety of shapes sizes and densities As a result the term forest can have many different meanings depending on where you are in the world and the purpose of the definition For example the boreal forests of Russia and Canada appear very different from the tropical rainforests of Brazil and Vietnam Figure 1 1 Additionally within Figure 1 1 The forests of the world such as the a boreal forests of northeastern Russia or the b tropical rainforests of southern Vietnam can be very different from one another 2 Field Guide for Forest Biomass and Carbon Estimation a given region similar forest types can serve a variety of different purposes For example a Canadian plantation of Douglas fir established for timber production will appear quite different from a Canadian old growth tract of Douglas fir designated for biodiversity conservation Given the diversity of forests globally many definitions of the term forest exist and several have been proposed in the context of measuring and monitoring forest biomass and carbon
21. come screen appears first and then changes to the Satellite page within a few seconds e To change the brightness of the screen press and release the POWER button quickly and then use the arrows on the ROCKER button to increase A or decrease V the brightness e To turn the GPS off press and hold the POWER button until the LON unitshuts down Location N 4152750 8 0710647 4 Using the Satellite page The Satellite page provides the user ae with information about the number of satellites that are currently in e view of the GPS receiver Figure W 2 6 Depending on the location of the receiver it may take several minutes for all visible satellites to appear on the screen e For the GPS to compute its current horizontal location 2 D or horizontal mode at least 3 satellites must be in view of the receiver A strong signal from each satellite is GPS Navigation required for an accurate position fix Bars at the bottom of the screen increase in height and become darker as the signal strength of each satellite increases e For the GPS to compute its current horizontal position and elevation 3 D or vertical mode at least 4 satellites must be in view of the receiver e The current location is shown at the top of the screen in units of the user selected coordinate system The positional accuracy is shown as well e g 8 meters Figure 2 6 5 Using the Map page e The Map page is used for orientat
22. cy for Development Cooperation Forum on Readiness for REDD Lisa Cavanaugh Tina Cormier Tracy Johns Connie Johnson Nadine Laporte Chris Meyer Kristin McLaughlin Andr Nahur Kathleen Savage and Allison White provided valuable comments on an earlier draft The Woods Hole Research Center conducts interdisciplinary scientific research on forests soils water and energy for the benefit of sustained human well being on Earth We are leaders at the nexus of science economics and public policy through innovative communication and education about environmental challenges and solutions The Center has initiatives in the Amazon the Arctic Africa Asia Russia Boreal North America the Mid Atlantic and New Eng land including Cape Cod Center programs focus on the global carbon cycle forest function land cover land use water cycles and chemicals in the envi ronment science in public affairs and education providing primary data and enabling better appraisals of the trends in forests Mention of trade names or commercial products if any does not constitute endorsement di Tro A ne gt X Woods Hole Research Center GORDON AND BETTY the David MOORE google org lt p Shard FOUNDATION FOUNDATION FORUM ON READINESS FOR REDD SED 4 mn 7
23. de of the tape the scale corresponds to units of diameter also often measured in centimeters Figure 4 3b Here diameter refers to the distance measured straight through the center of the tree trunk Figure 4 4a To measure the DBH of a tree using a diameter tape the steel tape is wrapped around the tree i e its circumference Figure 4 4b at 1 3 m above a b Figure 4 4 Zhe a diameter and b circumference of a typical tree the ground with the diameter scale of the tape facing out Figure 4 5 Care should always be taken to ensure that the tape is held in a level position as it is wrapped around the tree The diameter measurement is then read from the tape to the nearest tenth of a centimeter Although the tape is wrapped around the circumference of the tree when obtaining a DBH measurement diameter tapes are designed so that the conversion from circumference to diameter is done automatically Because the diameter tape has two differ ent scales distance and diameter it is important that diameter measure ments be taken using the correct side of the tape i e the side with the diameter scale Figure 4 3 Diameter tapes have the advantage of being small compact devices that can be easily carried in a pocket They are made of steel or reinforced nylon that will not stretch or deform with changes in temperature or when wet Diameter tapes also have a hook at the end of the tape that can be embedded in the bark of a tree to
24. e navigation function GPS Navigation Figure 2 26 Zhe Compass page with directional arrow What s in Chapter 3 Forest measurements of the sort used in the estimation of aboveground biomass and carbon are typically obtained within sample plots Sample plots are relatively small areas carefully delineated in the field within which measurements of individual trees and or shrubs are obtained In this chapter you will learn about the various tools and techniques used to establish sample plots suitable for obtaining estimates of aboveground biomass and carbon B Plot Me SEK os 7i x ye v What is a sample plot In the fields of forestry and ecology a sample plot defines an area on the ground within which measurements and observational data e g on plants animals soils etc are recorded based on a predetermined set of procedures referred to as a measurement protocol Sample plots are of ten of a fixed size Examples include 100 m x 100 m square 25 m x 100 m rectangular or 25 m radius circular with all representing a clearly defined area on the ground The size and shape of a plot can vary greatly depending on the type of data that is being collected Where the estimation of forest biomass and carbon is concerned sample plots need to be large enough to include any local variability in the type and density of trees present There fore larger p
25. erstanding the role that forests play in the global carbon cycle and for learning the tools and techniques most commonly used in estimating the carbon content of forests VAL LOMA A ES Fa apes M Mou PT v Wu m d EA x A N a E hu 7 gt wel pas Ji gt Introduction Y ES t y E oak 2 i AN NEC COME MS 3 de E p 8 n 5s gt gx Forests provide a wide range of natural benefits including air purification watershed protection and biodiversity conservation while also being sources of food fiber and medicine Forests also play an important role in maintaining the stability of the global climate Trees and other forest plants remove large amounts of carbon dioxide CO a greenhouse gas GHG from the atmosphere as they grow storing the carbon in the biomass of their leaves branches stems and roots Because forests have a tremendous capacity for carbon uptake and storage in addition to reducing GHG emissions from fossil fuels one of the most effective ways to remove carbon from the atmosphere is through the sustainable management of forests Recognition of the important connections between forests carbon and climate has prompted calls from groups ranging from indigenous peoples to government ministries for sources of basic information on the tools and techniques used to obtain ground based estimates of carbon
26. evelopment Cooperation Forum on Readiness for REDD Layout adapted from 2009 Commonwealth of the Northern Mariana Islands CNMI Erosion and Sediment Control Field Guide CNMI Department of Environmental Quality Introduction GPS Navigation Sample Plot Layout Tree Diameter Measurement Biomass and Carbon Estimation d AC CHAPTER M ES 6 Additional Resources License information This field guide is licensed under the Creative Commons Attribution Non Commercial 3 0 Unported License To view a copy of this license visit http creativecommons org licenses by nc 3 0 or send a letter to Creative Commons 444 Castro Street Suite 900 Mountain View California 94041 USA You are free to adapt copy distribute and transmit the guide under the fol lowing conditions e You must attribute the work in the manner specified by the author or licensor but not in any way that suggests that they endorse you or your use of the work e You may not use this work for commercial purposes y If you make reference to this field guide we ask that you use the citation sug gested on the inside front cover Introduction Chapter 1 7 s p JR 2M d EN ABI MS A E What s in Chapter 1 What is a forest What is carbon Why is there interest in forest carbon This chapter answers these and other fundamental questions laying a foundation for und
27. g beneath dense forest canopies like those found in the tropics requires a GPS receiver that is capable of receiv ing and processing relatively weak satel lite signals Because many recreational grade GPS units are not equipped to re ceive weak signals care should be taken Figure 2 2 Zhe Garmin GPSmap 60C3Sx handheld GPS receiver when selecting a GPS receiver to ensure that the unit is appropriate for the type of environment where it will be used For the purposes of this tutorial on GPS navigation the Garmin GPS map 60CSx has been selected Figure 2 2 This unit features a high sen sitivity receiver providing for improved satellite reception even in heavy tree cover or deep canyons Before going into the field it is advisable to evaluate the performance of any GPS unit particularly if you are unfa miliar with its operation by testing it under conditions similar to those expected on the ground When preparing a GPS receiver for use it is important to confirm that the unit is properly configured so that the data being collected will meet all project requirements Receivers often have a number of optional settings that users can adjust to allow for easier operation Other settings must be carefully selected so as to be certain that accurate position information will be acquired Five of the most important settings include 1 Coordinate system It is critical that the preferred coordinate system e g geographic or UTM and
28. h dense undergrowth After measuring the DBH of a tree the tree should be marked with a brightly colored crayon or piece of flagging so that it is not ac cidentally measured more than once Commonly a large X or similar mark is placed on the tree Fig ure 4 7 Marks should be placed consistently at the same height and posi tion on each tree so that Figure 4 7 A tree marked with an orange crayon to one can quickly determine indicate that a DBH measurement has been taken Boma discancesba nee has already been measured Note A complete list of the equipment items described in this chapter can be found in the Additional Resources section located at the end of this guide Which trees should be measured The measurement protocol for any field campaign should specify which trees in a sample plot are to be measured For example in protocols being used to obtain estimates of aboveground forest biomass and carbon it is recom mended that all live trees greater than or equal to 5 cm in diameter be mea gt s Tree Diameter Measurement 35 sured A 5 cm threshold ensures that the majority of trees contributing to the total AGB of the plot are included in the final estimate Trees i e saplings less than 5 cm in diameter are often not measured because they tend to have very little biomass overall and are often too numerous to measure efficiently Additionally protocols should address whether or not lianas v
29. he MENU button and then use the ROCKER button to scroll down to the Calibrate Compass option Figure 2 18 Once selected press the ENTR button e A screen will appear with the instructions To Calibrate Compass Slowly Turn Two Full Circles In The Same Direction While Holding The Unit Level On the screen the Start option should be highlighted Figure 2 19 Press the ENTR button and follow the instructions as described above e A new screen will provide information on the progress of the calibration Once the calibration is complete press either the QUIT or ENTR buttons to return to the main Compass page 9 Storing waypoints One of the most common uses of a GPS receiver is waypoint storage A waypoint can be stored to mark i e permanently record the location of a specific point of interest such as the center of a forest sample plot so that the plot can be efficiently and accurately re located in the future The Garmin GPSmap 60CSx can store up to 1000 waypoints Once a specific point of interest has been reached press the MARK button to store a waypoint position GPS Navigation GPSmap 60CSx GPSmap 60C 5x 11 SEP 10 206314 locaton _ N 41 52755 W070 65657 Elevation Depth Figure 2 20 7he Mark Waypoint page Figure 2 21 The Average Location page A Mark Waypoint page opens where the waypoint can be named the location of the waypoint can be viewed and or changed and
30. ines palms and or standing dead trees are to be measured Lianas vines and palms tend to have lower wood densities and hence lower biomass compared to other tree species As a result measurements may not be taken particularly if this group represents only a small proportion of the forest stand Standing dead trees tend not to be measured as part of AGB estimates because they tend to remain standing for only relatively short periods of time before leaving the aboveground carbon pool to join the litter layer and soil carbon pools How are measurements taken on trees of unusual size and shape As explained above DBH measurements are typically taken at 1 3 m above the ground This standard is used because for the majority of trees trunk diameter tends to be relatively uniform above 1 3 m However it is not uncom mon in nature to find trees that have un usual trunk characteristics For exam ple a tree trunk may be buttressed at 1 3 m Figure 4 8 In cases such as this a measurement taken at breast height will not be representative of the tree s average diameter General rules have been established for measuring the DBH of special case trees What follows is a series of illus trations and accompanying photographs that can be used in the field to determine how best to obtain DBH measurements Figure 4 8 A tree with buttresses of trees with unusual trunk characteris extending well above 1 3 m tics If a special case t
31. ion ing system consisting of a constellation of 24 satellites orbiting the Earth Figure 2 1 These satellites work together with hand held GPS receivers Figure 2 2 to accurately determine where we are posi tion where we are going distance and direction and how fast we are moving speed on the surface of the Earth The information provided by GPS is available 24 hours a day and can be accessed in any weather conditions from anywhere in the world How does GPS work Each GPS satellite sends out a continuous stream of signals toward the Earth These signals are received and processed by GPS receivers A GPS receiver must receive signals from at least four satellites simultaneously for an accurate position to be computed and the location to be displayed on the receiver s screen Specific locations commonly referred to as waypoints are displayed by a GPS receiver using one of several global coordinate systems which rely on sets of numbers to precisely identify positions on the Earth s surface Ex amples include the geographic latitude longitude and Universal Transverse GPS Navigation Mercator UTM coordinate systems Things to consider Hand held GPS receivers have become popular tools for navigating to way points in the field as well as recording waypoint positions so that they can be re located in the future Working in some environments requires the use of special GPS receivers For example navigatin
32. ion navigating to waypoints and measuring distances Figure DO e A small black triangle on the screen identifies the user s location on the map and indicates the direction that the unit is pointing e A blue circle around the black triangle indicates the positional accuracy a smaller circle means higher accuracy and a larger circle means lower accuracy Ihe rotating arrow labeled with the letter N in the upper left of the screen is a north arrow which always points in the direction of north e The Garmin GPSmap 60CSx comes with a base map that displays major roads for most regions of the world e The IN and OUT buttons on the keypad can be used to zoom in and out of the current map display e The ROCKER button can be used to scroll around the Map page The QUIT button allows the user to back out of any menu or operation and return to the previous menu page Figure 2 7 Zhe Map page 12 Field Guide for Forest Biomass and Carbon Estimation 6 Using the Main Menu page e Press the PAGE button until the Main Menu page is reached Figure 2 8 The most commonly used options on this page include Tracks Used to save the track or path of current progress toward a destination Setup For a detailed description see the next section Section 7 below Calculator Includes calculator functions useful for standard and scientific calculations GPSmap 60CSx GPSmap 60CSx Display Interface 1131 Page
33. lots e g 100 m x 100 m are generally preferred over smaller plots e g 25 m x 25 m In this chapter meth ods are described for establishing a typical Sample Plot Layout Plot Center Figure 3 1 Diagram of a typical square 40 m x 40 m sample plot square sample plot measuring 40 m x 40 m Figure 3 1 This particular plot shape and size is intended to serve as an example and will not be appropriate in all cases When larger or smaller plots are required the methods described here can be easily adapted Establishing the plot To establish a sample plot in the field one must first know where and how the plot is to be located For the purposes of this example we will assume that the location of the plot center point has been determined in advance of the field visit The preferred method for navigating to a sample plot should be described in the particular measurement protocol being used In Chapter 2 of this guide GPS was presented as an efficient and accurate tool for navigating to a specific location in the field such as the center point of a sample plot Because this point serves as the primary reference from which the locations of the plot corners and boundaries are de termined care must be taken to en sure that the plot center is located as accurately as possible Once the position of the plot cen ter is located in the field it is im portant that it be clearly marked A common approach to ma
34. mplete list of the equipment items refer enced in this guide e Handheld GPS receiver e g Garmin GPSmap 60CSx e Diameter tape e Sighting compass e Fiberglass measuring tapes as many as the plot dimensions require e Flagging brightly colored for marking plot boundaries e Lumber crayons brightly colored for marking trees e Camera for taking photographs of the plot e Paper for printing plot forms e Pencils e Clipboard e Backpack for carrying all of the above For further information on these items please visit the websites listed under Field Equipment on the preceding page Additional Resources Obtaining copies Electronic copies of this field guide are available in Adobe Acrobat PDF for download from the following websites Woods Hole Research Center www whrc org The REDD Desk www theredddesk org A limited number of printed copies may be available from the Woods Hole Research Center upon written request Contact information If you have questions or comments on this field guide please contact Dr Wayne Walker wwalker whrc org Woods Hole Research Center 149 Woods Hole Road Falmouth Massachusetts 02540 1644 USA Photography and graphics Max Nepstad Tina Cormier Wayne Walker and Mike Loranty Acknowledgements Support for the production of this field guide was provided by the Gordon and Betty Moore Foundation Google org the David and Lucile Packard Founda tion and the Norwegian Agen
35. n In general water accounts for approximately 50 or of the weight or wet biomass of a live tree Figure 1 2 What is carbon Carbon is one of the most abundant chemical elements on Earth and is pres ent in all living things It is also a naturally occurring component of Earth s atmosphere Denoted by the symbol C carbon is found in large quantities in the leaves branches stems and roots of trees In addition to being made up of 50 water the biomass of a live tree contains approximately 25 carbon Figure 1 2 The remaining 25 is made up of varying amounts of other elements including Nitrogen N Phosphorous P Potassium K Calcium Ca Magnesium Mg and other trace elements However if all the water contained in a live tree were removed the proportion of the remaining dry biomass that consists of carbon would increase from 25 to 50 Figure 1 2 Therefore carbon makes up roughly of the total AGB of a tree For example if a tree has an AGB of 2 4 metric tons then the carbon found in that tree has a weight of 1 2 metric tons i e 2 40 t 2 1 20 t Figure 1 2 Why is there interest in carbon Carbon is found in the chemical compounds carbon dioxide CO and methane CH two greenhouse gases that occur naturally in the atmo sphere but are also produced in large quantities through human activities namely the burning of fossil fuels such as coal and oil Greenhouse gases act like a blanket above the Earth tr
36. n forest measurements acquired worldwide is the diameter at breast height or the DBH of trees In the field of forestry breast height defined at 1 3 meters or 4 5 feet above the ground Figure 4 1 is the interna tionally recognized standard height at which tree diameter is measured Measurements of DBH are used in calculating estimates of timber vol ume basal area and aboveground biomass carbon of individual trees and entire forests Taking the DBH measurement of a tree is relatively easy to do and with some practice measurements of many trees can be obtained quickly and accurately in the field How is tree diameter measured An appropriate measuring device should be used to obtain the DBH of a tree The two most common tools used for DBH measurement are the diameter tape and the caliper Figure 4 2 A diameter tape is a special measuring device that typically has two different scales one on each side of a white steel Tree Diameter Measurement 31 Figure 4 3b 77e side of the diameter tape that is used for diameter measurement 32 Field Guide for Forest Biomass and Carbon Estimation tape Figure 4 3 On one side of the tape the scale corresponds to standard units of distance typically measured in centimeters Figure 4 3a This scale can be used to determine the position of breast height 1 3 m on a tree trunk or measure the circumference i e distance around the trunk of a tree On the other si
37. ning biomass estimates for many trees or entire tracts of forest The limitations associated with direct methods have led numerous researchers to develop mathematical relationships commonly referred to as allometric equations which relate the aboveground biomass of individual trees to other tree characteristics that are more easily measured in the field These charac teristics include diameter at breast height DBH see Chapter 4 total height and wood density Hundreds of allometric equations have been developed for individual tree species and groups of tree species by researchers all over the world Examples of allometric equations that relate AGB to DBH and wood density for three different groups of topical forest tree species are shown in Figure 5 1 These groups include dry tropical forest red line wet tropical forest green line and moist tropical forest blue line As described in Chapter 4 DBH measurements are easily obtained in the field Wood density estimates are typically obtained by computing the dry weight i e mass per unit vol ume of stem samples collected in the field and several compilations of wood density values have been published by various researchers e g Brown 1997 see the Additional Resources section for more information Biomass and Carbon Estimation u En 55 axrf15 t2 8 x oy D 02607 xL 0 028 x Lal 151 oan pt e S E per heclave Moist tropical forest
38. ntact the international community is working to implement policies that would compensate tropical nations for reducing carbon emis sions from tropical deforestation and forest degradation Successful policies will require among other things the development of operational forest mea surement and monitoring systems to track gains and losses in forest carbon over time This field guide describes some of the basic tools and techniques that would likely form the foundation for any forest measurement and moni toring system For further information on these and other topics please see the Additional Resources section at the end of the guide Introduction Chapter 2 What s in Chapter 2 Obtaining ground based measurements of forests typically requires field crews to navigate to specific pre determined locations where measurements are to be taken or record the positions of specific locations after measurements have been acquired Finding and marking measurement locations is most easily accomplished using a hand held GPS receiver In this chapter you will learn what GPS is how it works and how GPS receivers can be used in the field for efficient and accurate navigation a 4 GPS Navigation Figure 2 1 77e Global Positioning System consists of a constellation of 24 satellites Graphic courtesy of GPS gov N 2 gt A x 2 What is GPS The Global Positioning System GPS is a worldwide navigation and posit
39. o a stored waypoint press the FIND button The Find page opens Figure 2 23 Select the Waypoints icon and press ENTR e A screen appears with a list of stored waypoints and a small keyboard The keyboard allows the user to search the list for a particular waypoint to remove the keyboard from view press QUIT Figure 2 24 Select the waypoint that you wish to find and press ENTR The Find Waypoint page appears Figure 2 25 Use the ROCKER button to select the Go To option at the bottom of the page waypoints can also be deleted from this screen using the Delete option at the bottom of the page Press the ENTR button e Selecting the Go To option starts the unit navigating to the selected waypoint The user is initially taken to the Map page where the straight line path to the selected waypoint is displayed 20 Field Guide for Forest Biomass and Carbon Estimation e Use the PAGE button to reach the Compass page While holding the compass level the arrow on the Compass screen indicates the direction to the selected waypoint Figure 2 26 The user can then travel in the direction of the arrow to reach the waypoint The distance to the waypoint and the speed of travel toward the waypoint are both displayed on the screen e From either the Map or the Compass page the user can stop navigating to a waypoint by pressing the MENU button In the menu that appears select the Stop Navigation option and press ENTR This cancels th
40. option and press ENTR The unit will then store the averaged average location and place a waypoint on the Map page eMap A single position fix is taken at the current location and is stored When the Map option is selected the screen view changes automatically to the Map page where the new waypoint is displayed Figure 2 22 e OK A single position fix is taken at the current location and is stored No averaging is performed When the OK option is selected the screen view changes automatically to the page that was being viewed prior to the user pressing the MARK button NOTE Pressing the MARK button will initiate the waypoint storage function regardless of the current page GPSmap Exits Recent Find Figure 2 22 Zhe Map page with Figure 2 23 Zhe Find page waypoint label GPS Navigation GPSmap 60CSx GPSmap 60CSx ET Symbole E Near Map Pointer 2 87 Nate 11 SEP 10 2 1 1 47PH Location N 41 52388 07066153 Elevation Depth m m m From Current Location 571m SS Figure 2 24 Zhe Waypoint List page Figure 2 25 Zhe Find Waypoint page 10 Navigating to stored waypoints Often a GPS user wants to navigate to i e find a known location that was previously stored as a waypoint For example one might want to revisit a previously established i e permanent forest sample plot so that updated measurements can be acquired e To navigate t
41. pad Keypad buttons allow the user to turn the unit on and off change pages on the screen mark and find waypoints and access the overall functionality of the unit A description of each keypad button follows e POWER Located at the top of the unit Used to turn the unit on or off as well as adjust the screen brightness Figure 2 4 e ROCKER Large round button with diamond shaped arrows lt gt A W used to scroll around maps or menus as well as select options Figure 2 5 e IN OUT Allows the user to zoom in and out while navigating the Map page Figure 2 5 e PAGE Allows the user to move among the various pages or screen views like the Map Satellite or Compass pages Figure 2 5 e MENU Provides access to all menus and submenus of a particular page Figure 2 5 Figure 2 4 7 e On Off button 10 Field Guide for Forest Biomass and Carbon Estimation ENTR Used to execute selected options Figure 2 5 QUIT Allows the user to exit out of the current menu or page The user is taken to the previous menu or page Figure 2 5 e MARK Allows the user to store the location of a waypoint Figure 2 5 e FIND Allows the user to navigate to the location of a previously stored waypoint Figure 2 5 Figure 2 5 Zhe keypad 3 Turning the GPS on off e To turn the GPS on press and hold the POWER button at the top of the unit for three seconds Figure 2 4 e The wel
42. perature Set to Fahrenheit or Celsius depending on personal preference e Pressure Set to Millibars Heading Allows the user to specify how North is referenced and displayed by the compass Figure 2 16 Set to Magnetic 8 Calibrating the compass e When a new unit is first turned on after replacing the batteries or before navigating to a waypoint it is wise to recalibrate the electronic compass This will ensure that the compass is functioning properly during navigation Make sure that the unit is turned on and a position fix has been acquired Press the PAGE button until you reach the Compass page Figure 2 17 The compass dial on this page points in the direction that the GPS is oriented The top of the screen displays useful information including speed of movement straight line distance to a selected waypoint and estimated time of arrival at the waypoint given the current rate of progress GPSmap 60CSx GPSmap 0C 5x WEEZE Display Cardinal Letters North Reference True Switch to compass heading when below 16 for more than 90 Figure 2 16 Zhe Heading setup Figure 2 17 Zhe Compass page 16 Field Guide for Forest Biomass and Carbon Estimation GPSmap 60C Sx MINOS B To Calibrate Compass Slowly Turn Two Full Circles In The Same Direction While Holding The Unit Level Figure 2 18 Ze Compass menu Figure 2 19 Zhe Compass Calibration page e To calibrate the compass press t
43. pter provides information specific to the usage of the Garmin GPSmap 60CSx For further general information on GPS technology please see the Additional Resources section located at the end of the guide If you are using a GPS receiver other than the Garmin GPSmap 60CSx please consult the user manual specific to that unit for further information Using the Garmin GPSmap 60CSx In this section the following topics are discussed Replacing the batteries Understanding the keypad Turning the GPS on off Using the Satellite page Using the Map page Using the Main Menu page Understanding the Setup options Calibrating the compass Storing waypoints Navigating to stored waypoints PCR ROI m GPS Navigation e An adequate supply of spare batteries should always be carried in the field e To replace the batteries remove the back cover of the GPS receiver by flipping the metal ring up and turning it counter clockwise Figure 2 3 e Use the and indicators on the inside of the GPS to ensure that the two AA batteries are positioned correctly e Re attach the back cover by replacing the bottom edge first then snapping the top edge into place Press down on the metal ring while turning it clockwise to lock it in place NOTE Failure to attach the back cover properly could result in water entering the unit 1 Replacing the batteries Figure 2 3 he battery compartment 2 Understanding the key
44. ree is encountered that is not described in this guide com mon sense should be used together with the information provided in the following illustrations and photographs to determine at what point on the trunk the DBH should be measured to obtain a diameter estimate that is representative of the tree s average diameter 36 Field Guide for Forest Biomass and Carbon Estimation Upright trunk on level ground standard condition Measure the DBH at 1 3 m above the ground Unda trunk on sloping o Measure the DBH at 1 3 m y the ground while standing on the uphill side of the tree Tree Diameter Measurement eS Leaning tuak on sloping ground Measure the DBH at 1 3 m above the ground while standing on the uphill side of the tree 38 Field Guide for Forest Biomass and Carbon Estimation Tree Diameter Measurement DBH above the buttressed tapered portion of the trunk at a point where the trunk diameter becomes uniform Ladders or climbing equipment may be required in some cases Stilted roots at 1 3 meters Measure the DBH above the stilted portion of the trunk at a point where the trunk diameter becomes uniform 40 Field Guide for Forest Biomass and Carbon Estimation Deformed or branched trunk at 1 3 meters Measure the DBH at a point on the trunk above or below the deformity or branch where appropriate depending on the size and shape of the trunk Tree Diameter Measurement 41
45. rking the plot center is to drive a tall 2 m wooden stake securely into the ground The top of the stake is then wrapped with brightly colored flagging so that it can be easily seen Figure 3 2 A wooden stake with orange flag from a distance Figure 3 2 ging marks the plot center Measuring distances on the ground When laying out a sample plot distances are typically measured using an open reel fiberglass tape Figure 3 3 which can be purchased in varying lengths up to 100 m Regardless of the size and shape of the plot being used it is critical that all distances be measured accurately Hence care must be taken when laying out plots in areas with uneven terrain and 24 Field Guide for Forest Biomass and Carbon Estimation obstacles e g trees boul ders water bodies etc All distance measurements should be made horizon tally i e using horizontal distances above the surface of the ground as opposed to along the surface i e using slope distances The dif ference between horizontal distances and slope distances is illustrated in Figure 3 4 Figure 3 3 4 50 m open reel fiberglass measuring tape Thus when measuring dis tances over uneven terrain the measuring tape should be held horizontally regardless of the shape of the underlying ground surface and pulled taut to prevent sagging Figure 3 4 On particularly steep slopes it may be necessary to break the total distance being mea
46. s in a given area were cut down and burned for example to prepare the site for agriculture production approximately how much CO would be emitted to the atmosphere In such a scenario carbon previously stored in the leaves branches and stems of the trees would be converted to CO gas through the process of burning 46 Field Guide for Forest Biomass and Carbon Estimation Box A Aboveground live dry biomass calculation for a single tree Using the Chave et al 2005 allometric equation for moist tropical forest species see Figure 5 1 the aboveground live dry biomass AGB in metric tons of a single tree can be calculated as AGB ee p exp 1 499 2 148 In D 0 207 In DF 0 0281 In D 0 001 where is the wood density g cm and D is the diameter at breast height cm Thus for the first tree in the first quadrant of the plot see Figure 5 2 which has a wood density of 0 60 g cm and a DBH of 6 3 cm the AGB is calculated as AGB 0 60 exp 1 499 2 148 In 6 3 0 207 tree In 6 3 0 0281 In 6 3 3 0 001 AGB 0 012 metric tons Biomass and Carbon Estimation Box B Aboveground live dry biomass calculation for a sample plot Table 5 1 contains estimates of AGB for each of the 28 trees contained in the example sample plot shown in Figure 5 2 The estimates were calculated using the Chave et al 2005 allometric equation for moist tropical forest species as
47. sured into shorter more manageable pieces in order to obtain more ac curate horizontal measurements In Figure 3 4 three separate horizontal measurements of 4 2 m 2 8 m and 6 0 m are obtained to span the total horizontal distance of 13 m When obstacles block the path over which a measurement is to be taken the measurement can also be broken into shorter more manageable pieces in order to avoid the obstacle For example Figure 3 5 illustrates how to gt meters 13 meters 4 2 2 8 meters meters gt 6 0 Figure 3 4 Horizontal distances should be measured at all times particularly across uneven terrain M d Sample Plot Layout lt 10 0 meters gt Q lt 4 5 meters 3 5 meters gt O 1 0m 1 0m i offset offset Beginning v v End of line 2 0 meters gt of line Figure 3 5 When a tree or other feature obstructs the line measurements can be broken up into shorter lengths to avoid the obstacle In this example three measurements were taken totaling 10 m Le 4 5 m 2 0 m 3 5 m 10 m avoid a tree blocking the path of the measurement First the distance from the starting point to the near side of the tree is measured In this example the distance is 4
48. that would be emitted to the atmosphere if the 28 trees in the example sample plot were cut down and burned completely can be calculated as C0 AGB MW Where AGB is the total aboveground live dry biomass in the sample plot see Box B MW is the molecular weight of carbon dioxide and MW is the mo lecular weight of carbon Thus in this example where the total aboveground live dry biomass in the sample plot is approximately 24 5 metric tons the molecular weight of carbon dioxide is 44 and the molecular weight of carbon is 12 the weight of carbon dioxide emit ted to the atmosphere is calculated as CO 24 5 44 12 CO 24 5 3 67 CO 89 92 metric tons Biomass and Carbon Estimation Additional Resources What s in Chapter 6 This chapter includes a variety of resources that expand on the topics covered in this field guide 1 ME X Additional meee ces Resources Further Reading The following books reports articles and websites were consult ed during the preparation of this field guide Readers in search of additional information on the topics covered here are encouraged to consider these useful resources Books Field Measurements for Forest Carbon Monitoring 2010 C M Hoover ed Tree and Forest Measurement 2 Edition 2009 P M West Forest Mensuration 4 Edition 2003 B Husch T W Beers and J A Kershaw Jr Forest Measurements 5 Edition 2001 T E
Download Pdf Manuals
Related Search