1 Estimating carbon carrying capacity in natural forest ecosystems across heterogeneous 2 landscapes: addressing sources of error 3 Heather Keith, Brendan Mackey, Sandra Berry, David Lindenmayer, Philip Gibbons 4 Supporting Information 5 Appendix 1: Estimation of tree biomass 6 Estimation of tree biomass derived from stem volume needs to include a reduction factor to 7 account for decay in large trees (see Mackowski 1987, Lindenmayer et al. 2000, Dean et al. 8 2003, Roxburgh et al. 2006). For calculations of biomass from stem volume at the sites used in 9 southeast Australia, we applied a reduction factor to tree size categories of 50 – 120 cm DBH 10 (diameter of stem at 1.3 m height) and >120 cm DBH, based on relationships with DBH 11 described in Roxburgh et al. (2006). Additionally, we used a buttress modification factor 12 developed by Dean et al. (2003) where measurements of cross-sectional areas of buttresses were 13 used to derive a fractional area deficit formula of up to 40% for trees >3.5 m DBH. 14 The range in allometric equations used to estimate biomass at sites in southeast Australia is 15 shown in Figure S1. Separate curves are shown for allometric equations that include reduction 16 factors for decay in volume equations and buttressing in large trees. Factors influencing 17 differences among these equations include height of trees, taper of stems, proportion of branches, 18 wood density and amount of decay. Calculation of biomass for individual trees using these 19 allometric equations was estimated within the size range of trees used to derive the equation 20 (maximum tree sizes were DBH of 6.4 m for E. regnans (Mountain Ash) (Dean and Roxburgh 21 2006), 2.8 m for E. obliqua (Messmate), 1.8 m for E. piluaris (Blackbutt), 1.5 m for Corymbia 22 maculata (Spotted gum), 0.9 for E. delegatensis (Alpine Ash)). At the few sites where 1 1 extrapolations were necessary on the NSW south coast, a very conservative equation with an 2 asymptote was used. From the tree biomass data available to derive allometric equations, there is 3 no evidence that the largest trees in a sequence had a relatively lower biomass or were below the 4 trend line. However, it is important to be cautious in using these logarithmic equations as 5 extrapolation beyond the size range could cause significant errors. 6 Figure A1 7 Allometric equations derived for forest trees in southeast Australia. 8 1. Applegate (1982) E. pilularis Fraser Island, 2. Montagu et al. (2005) E. pilularis, 3. Keith et 9 al. (2009) E. delegatensis Tumbarumba, 4. Keith et al. (2000) E. delegatensis Brindabella 10 Ranges, 5. Ash & Helman (1990) Corymbia maculata with adjustment for decay, 6. Adams and 11 Attiwill (1988) E. obliqua, 7. Keith et al. (2000) E. obliqua southern forests Tasmania , 8. Turner 12 et al. (1989), 9. Mackowski (1987) E. pilularis north coast NSW 10. Ximenes et al. (2004) 13 Corymbia maculata, 11. Dean and Roxburgh (2006) E. regnans with adjustment for decay. 14 Solid lines represent the size range of trees harvested for biomass measurements. 15 [Figure A1] 16 References 17 1. Applegate GB (1982) Biomass of Blackbutt (Eucalyptus pilularis Sm.) forests on Fraser 18 19 Island. unpublished Masters thesis. University of New England, Armidale. 2. Montagu KD, Düttmer K, Barton CVM, Cowie AL (2005) Developing general allometric 20 relationships for regional estimates of carbon sequestration – an example using 21 Eucalyptus pilularis from seven contrasting sites. Forest Ecology and Management, 204, 22 113-127. 2 1 3. Keith H, Leuning R, Jacobsen KL et al. (2009) Multiple measurements constrain estimates of 2 net carbon exchange by a Eucalyptus forest. Agricultural and Forest Meteorology, 149, 3 535-558. 4 4. Keith H, Barrett D, Keenan R (2000) Review of allometric relationships for woody biomass 5 for NSW, ACT, Vic., Tas., SA. Australian Greenhouse Office, NCAS Technical Report 6 5b. 7 8 9 10 11 5. Ash J, Helman C (1990) Floristics and vegetation biomass of a catchment, Kioloa, south coastal New South Wales. Cunninghamia, 2, 167-182. 6. Adams MA and Attiwill PM (1988) Nutrient cycling in forests of north-east Tasmania. Research Report 1 Tasmanian Forest Research Council Inc., Hobart. 7. Keith H, Barrett D, Keenan R (2000) Review of allometric relationships for woody biomass 12 for NSW, ACT, Vic., Tas., SA. Australian Greenhouse Office, NCAS Technical Report 13 5b. 14 15 16 17 18 8. Turner J, Lambert M J, Kelly J (1989) Nutrient cycling in a New South Wales subtropical rainforest: Organic matter and phosphorus. Annals of Botany, 63,635-642. 9. Mackowski CM (1987) Wildlife hollows and timber management in Blackbutt forest: University of New England, Masters thesis. 10. Ximenes F deA, Gardner WD, Marchant JF (2004) Total biomass measurement and recovery 19 of biomass in log products in spotted gum (Corymbia maculata) forests of SE NSW. 20 Australian Greenhouse Office, NCAS Technical Report 47. 21 22 11. Dean C, Roxburgh SH (2006) Improving visualisation of mature, high-carbon-sequestering forests. Forest Biometry, Modelling and Information Sciences, 1, 48-69. 3 1 Dean C, Roxburgh S, Mackey BG (2003) Growth modelling of Eucalyptus regnans for carbon 2 accounting at the landscape scale. In: Modelling Forest Systems. Eds. A Amaro, D Reed & P 3 Soares, CABI, Oxon. pp. 27-39. 4 Lindenmayer DB, Cunningham RB, Pope ML, Gibbons P, Donnelly CF (2000) Cavity sizes and 5 types in Australian eucalypts from wet and dry forest types – a simple rule of thumb for 6 estimating size and number of cavities. Forest Ecology and Management, 137, 139-150. 7 Roxburgh SH, Wood SW, Mackey BG, Woldendorp G, Gibbons P (2006) Assessing the carbon 8 sequestration potential of managed forests: a case study from temperate Australia. Journal 9 of. Applied Ecology, 43, 1149-1159. 4 1 Appendix 2: Site carbon stock database for southeast Australia. 2 Table A2: Summary of key site attributes and modelled variables used in the analysis on a regional basis, with mean, ±SD and range. Living biomass (tC ha-1) Dead biomass (tC ha-1) Total biomass (tC ha-1) SE Queensland 397 (± 377) 67 (± 59) 465 (± 435) (99 - 821) (29 - 135) (129 - 956) North coast NSW 334 (± 125) 98 (± 66) (223 - 505) (30 - 181) South coast NSW 382 (± 191) (78 - 818) Southern tablelands NSW 299 East Gippsland, Victoria 406 (± 186) Region (± 2) (298 - 300) Central Highlands, Victoria (21 - 520) (± 38) (104 - 179) 29 (± 7) 15 (± 4) 19 (± 2) 1523 (± 67) 214 (± 6) (21 - 34) (11 - 18) (17 - 21) (1448 - 1574) (208 - 221) 432 (± 190) 152 (± 47) 30 (± 2) 15 (± 1) 16 (± 2) 1412 (± 158) 212 (± 1) (252 - 686) (94 - 192) (27 - 31) (13 - 15) (14 - 19) (1192 - 1548) (212 - 213) 82 (± 47) 464 (± 227) 293 (± 134) 27 (± 2) 13 (± 1) 12 (± 2) 1024 (± 84) 186 (± 2) (17 - 222) (95 - 980) (100 - 652) (20 - 30) (9 - 15) (9 - 16) (841 - 1243) (183 - 189) 105 (± 35) 404 (± 33) 180 (± 74) 27 (± 1) 12 (± 1) 11 (± 0) 916 (± 62) (80 - 129) (381 - 427) (128 - 232) (26 - 28) (12 - 13) (11 - 11) (872 - 959) (± 52) (9 - 266) 510 (± 228) 373 (± 99) 27 (± 2) 12 (± 1) 11 (± 2) 1075 (± 223) 183 (± 1) (55 - 1116) (174 - 631) (22 - 30) (10 - 14) (7 - 14) (671 - 1682) (181 - 185) (± 37) (4 - 173) 240 (± 140) 323 (± 140) 25 (± 3) 11 (± 1) 1173 (± 297) 189 (± 4) (24 - 635) (113 - 547) (17 - 28) (8 - 13) (6 - 13) (640 - 1650) (182 - 194) (± 42) (310 - 513) 27 (± 1) 13 (± 1) 10 (± 1) 1644 (± 179) 178 (± 1) (25 - 28) (12 - 13) (7 - 13) (790 - 1845) (177 - 181) 977 (± 315) 432 (± 145) 25 (± 0) 12 (± 0) 9 (± 1) 1572 (± 130) 148 (± 2) (673 - 1302) (303 - 589) (25 - 25) (12 - 12) (9 - 10) (1490 - 1722) (146 - 149) 105 50 501 (± 451) 1102 (± 656) (120 - 2092) (113 - 1865) (262 - 2884) (554 - 1100) Mean annual radiation (W m-2) NPP 581 (± 479) 810 (± 274) Tasmania Mean annual precipitation (mm) GPP (46 - 913) 190 (± 113) Montane Soil (tC ha-1) Mean annual temperature (C) 166 (± 43) (119 - 202) 144 421 9 (± 2) No. plots References 3 1, 2, 3 5 4, 5 62 6, 7, 8, 9, 10 2 11 114 9, 12, 13, 14 41 9, 11 54 15, 16, 17 3 11, 18 190 (± 1) (190 - 191) 5 1 References 2 1. Westman WE, Rogers RW (1977) Biomass and structure of a subtropical eucalypt forest, 3 4 5 6 7 8 9 10 11 North Stradbroke Island. Australian Journal of Botany, 25,171-191. 2. Applegate GB (1982) Biomass of Blackbutt (Eucalyptus pilularis Sm.) forests on Fraser Island. unpublished Masters thesis. University of New England, Armidale. 3. Hegarty EE (1991) Leaf litter production by lianas and trees in a sub-tropical Australian rain forest. Journal of Tropical Ecology, 7,201-214. 4. Mackowski CM (1987) Wildlife hollows and timber management in Blackbutt forest: University of New England, Masters thesis. 5. Turner J, Lambert M J, Kelly J (1989) Nutrient cycling in a New South Wales subtropical rainforest: Organic matter and phosphorus. Annals of Botany, 63,635-642. 12 6. Woldendorp G (2000) Estimating carbon in mature Eucalypt forests. BSc. Hons. Thesis, ANU. 13 7. Mackey BG (unpublished data) 14 8. Turner J, Lambert MJ (1986) Effects of forest harvesting nutrient removals on soil nutrient 15 reserves. Oecologia, 70,140-148. 16 9. Claridge A. (unpublished data) 17 10. Ximenes F deA, Gardner WD, Marchant JF (2004) Total biomass measurement and recovery 18 of biomass in log products in spotted gum (Corymbia maculata) forests of SE NSW. 19 Australian Greenhouse Office, NCAS Technical Report 47. 20 11. Keith H (unpublished data) In: Keith H, Barrett D, Keenan R (2000) Review of allometric 21 relationships for woody biomass for NSW, ACT, Vic., Tas., SA. Australian Greenhouse 22 Office, NCAS Technical Report 5b. 6 1 12. Jacobsen KL (unpublished data) 2 13. Stewart HTL, Flinn DW, Aeberli BC (1979) Above-ground biomass of a mixed Eucalypt 3 forest in eastern Victoria. Australian Journal of Botany, 27,725-740. 4 14. Gibbons P (unpublished data) 5 15. Ashton DH (1976) Phosphorus in forest ecosystems at Beenak, Victoria. Journal of Ecology, 6 7 64, 171 -186. 16. Van Pelt R, Sillett SC, Nadkarni NM (2004) Quantifying and visualizing canopy structure in 8 tall forests: methods and a case study. In: Forest Canopies, eds. MD Lowman, HB Rinker, 9 Elsevier Academic Press. pp 49-72 10 17. Lindenmayer DB (unpublished data) 11 18. Dean C, Roxburgh S, Mackey BG (2003) Growth modelling of Eucalyptus regnans for 12 carbon accounting at the landscape scale. In: Modelling Forest Systems. Eds. A Amaro, D 13 Reed, P Soares, CABI, Oxon. pp. 27-39. 7 1 Appendix 3: Global site data for NPP:GPP. 2 Table A3. Field site data for forest trees with measured GPP and NPP. Climate data was obtained from www.cru.uea.ac.uk/cru/data/tmc.htm if site data 3 was not provided in the reference. Climate data was extracted for the site latitude and longitude from the 10 minute grid cell and mean annual 4 temperature and precipitation calculated from the mean monthly values. Modelled Species Biome Tree type Latitude Longitude Pglobal Tglobal W Qs_global (mm yr-1) (°C) (mm yr-1) (MJ m-2 yr-1) GPP (tCha-1yr-1) NPP:GPP NPP:GPP Ref. Picea mariana (north) Pinus banksiana (north) Populus tremuloides (north) Picea mariana (south) Pinus banksiana (south) Populus tremuloides (south) boreal conifer 55.8833º N 98.3333º W 519 -3.3 -1026 3784 8.6 0.29 boreal conifer 55.8833º N 98.3333º W 519 -3.3 -1026 3784 6.8 0.34 boreal deciduous 55.8833º N 98.3333º W 519 -3.3 -1026 3784 9.0 0.46 boreal conifer 55.8833º N 104.8833º W 469 -0.3 -1268 4257 7.9 0.39 boreal conifer 55.8833º N 104.8833º W 469 -0.3 -1268 4257 5.5 0.43 boreal deciduous 55.5666º N 106.2333º W 484 -0.4 -1060 3784 10.4 0.42 Pinus sylvestris Picea sitchensis, Tsuga heterophylla boreal conifer 62.8666º N 30.8167º E 633 1.8 -397 2523 10.2 0.54 temperate conifer 45.0500º N 123.9500º W 2023 9.5 92 4730 14.0 0.49 Alnus rubra Pseudotsuga menziesii, Quercus garryana Tsuga heterophylla, Pseudotsuga menziesii Tsuga mertensiana, Abies, Picea temperate deciduous 45.0500º N 123.9500º W 2023 9.5 92 4730 15.6 0.52 temperate conifer 44.6000º N 123.2667º W 1151 11.0 -780 4730 16.7 0.46 temperate conifer 44.6667º N 122.6000º W 1871 8.3 -60 4730 24.0 0.47 temperate conifer 44.4167º N 121.8333º W 1241 6.3 -690 4730 8.8 0.42 Pinus ponderosa temperate conifer 44.4167º N 121.6667º W 1241 6.3 -690 4730 3.6 0.44 0.39 1 0.39 1 0.42 1 0.40 1 0.40 1 0.45 1 0.50 2 0.51 3 0.55 3 0.50 3 0.50 3 0.46 3 0.46 3 8 Juniperus occidentalis Pinus radiata – control Pinus radiata – irrigated Pinus radiata – irrigated and fertilized Quercus rubra, Acer rubrum Q. alba, Q. pinus, Carya ovata Pinus ponderosa E. delegatensis 2001-02 E. delegatensis 2002-03 Pinus sylvestris, Quercus robur E. pauciflora – control E. pauciflora - P fertilizer Pseudotsuga menziesii 17 yr Pseudotsuga menziesii 56 yr tropical forest old growth temperate conifer 44.2833º N 121.3333º W 359 8.3 -1572 4730 3.0 0.40 temperate conifer 35.3500º S 148.9333º E 873 12.6 -1702 6307 24.2 0.46 temperate conifer 35.3500º S 148.9333º E 873 12.6 -1702 6307 25.3 0.50 temperate conifer 35.3500º S 148.9333º E 873 12.6 -1702 6307 34.4 0.48 temperate deciduous 42.5333º N 72.1833º W 1698 8.0 -233 4730 12.5 0.53 temperate deciduous 35.9500º N 84.2833º W 1323 14.1 -994 5676 17.3 0.55 temperate conifer 44.0500º N 121.6167º W 1078 3.8 -1111 5361 9.0 0.45 temperate evergreen 35.6434ºS 148.1456ºE 1104 12.7 -1470 6307 22.1 0.51 temperate evergreen 35.6434ºS 148.1456ºE 1104 12.7 -1470 6307 17.0 0.49 temperate conifer 51.3092º N 4.5206ºE 792 10.0 -495 3154 10.4 0.56 temperate evergreen 35.3897ºS 148.8039ºE 1088 10.9 -1487 6307 17.0 0.43 temperate evergreen 35.3897ºS 148.8039ºE 1088 10.9 -1487 6307 16.8 0.48 temperate conifer 49.5217º N 124.9031ºW 1572 8.6 -101 4100 13.4 0.56 temperate conifer 49.8706º N 125.3367ºW 1986 8.0 313 4100 20.8 0.61 tropical evergreen 2.5833º S 50.1000ºW 2374 27.0 -458 6938 30.4 0.51 0.45 3 0.45 3 0.45 3 0.45 3 0.52 3 0.53 4 0.41 5 0.46 6 0.46 6 0.54 7 0.45 8 0.45 8 0.51 9 0.53 9 0.60 4 9 1 Figure A3 2 Global data for NPP:GPP at forest sites, distinguished by tree type: () evergreen, () deciduous, 3 () conifer forests. The dashed line represents a constant ratio of 0.47 that is commonly used in 4 carbon models. 5 [Figure A3] 6 References 7 1. Ryan MG, Lavigne MB, Gower ST (1997) Annual carbon cost of autotrophic respiration in 8 boreal forest ecosystems in relation to species and climate. Journal of Geophysical Research 9 102:28871-28883. 10 2. Zha T, Xing Z, Wang K-Y, Kellomäki S, Barr AG (2007) Total and component carbon fluxes 11 of a Scots pine ecosystem from chamber measurements and eddy covariance. Annals of Botany 12 99:345-353. 13 3. Waring RH, Landsberg JJ, Williams M (1998) Net primary production of forests: a constant 14 fraction of gross primary production? Tree Physiology 18: 129-134. 15 4. Malhi Y, Baldocchi DD and Jarvis PG (1999) The carbon balance of tropical, temperate and 16 boreal forests. Plant, Cell and Environment 22: 715-740. 17 5. Law BE, Ryan MG, Anthoni PM (1999) Seasonal and annual respiration of a ponderosa pine 18 ecosystem. Global Change Biology 5: 169-182. 19 6. Keith , Leuning R, Jacobsen KL, Cleugh HA, van Gorsel E, Raison RJ, Medlyn BE, Winters 20 A, Keitel C (2009) Multiple measurements constrain estimates of net carbon exchange by a 21 Eucalyptus forest. Agricultural and Forest Meteorology 149: 535 – 558. 10 1 7. Nagy MT, Janssens IA, Yuste JC, Carrara A, Ceulemans R (2006) Footprint-adjusted net 2 ecosystem CO2 exchange and carbon balance components of a temperate forest. Agricultural and 3 Forest Meteorology 139:344-360. 4 8. Keith H, Raison RJ, Jacobsen KL (1996) Allocation of carbon in a mature eucalypt forest and 5 some effects of soil phosphorus availability. Plant and Soil 196: 81-99. 6 9. Schwalm CR, Black TA, Morgenstern K, Humphries ER (2007) A method for deriving net 7 primary productivity and component respiratory fluxes from tower-based eddy covariance data: a 8 case study using a 17-year data record from a Douglas-fir chronosequence. Global Change 9 Biology 13:370-385. 10 11 1 Appendix 4: Method for calculation of Gross Primary Productivity over the southeast 2 Australia case study region 3 A spatial data layer of GPP was calculated from climate and satellite imagery of forest cover 4 using the simplified light-use efficiency model of GPP as formulated by Roderick et al. (2001). 5 PG e' f *C ' 6 where, e (mol CO2 mol-1 PAR) is the efficiency of the canopy modified to account for diffuse 7 light as described below, f is the fraction of photosynthetically active radiation (PAR, = 400 to 8 700 nm) absorbed by the canopy, Rs is solar irradiance (MJ m-2 d-1) received at the surface, Ro is 9 the global solar irradiance at the top of the atmosphere, and C is a conversion factor to convert * Rs ' Ro ' Ro ' (3) 10 MJ to mol PAR (2.3 mol PAR MJ-1). The superscripts denote that the input variables are: ′ 11 monthly (long term) averages (m2 d-1), or * values specific to a particular month and year. This 12 formulation takes into account the effect of diffuse solar radiance on the carbon assimilation rate 13 of the canopy (Roderick et al. 2001). 14 Roderick et al. (2001) derived the following general equations to estimate e for Australia; 15 e' 0.024 16 Rd ' R' 1.11 1.31 s Rs ' Ro ' Rd ' 0.012 Rs ' (4) (5) 17 where Rd ' Rs ' is the estimated fraction of the solar irradiance received at the surface that is 18 diffuse. Solar irradiance received at the surface (Rs′) was computed using monthly averages from 19 the BIOCLIM database. Solar irradiance received at the top of the atmosphere (Ro′) was 20 computed for monthly time steps using the formulae given in Roderick (1999). 12 1 The fraction of photosynthetically active radiation absorbed by the canopy (f*) was estimated 2 from a time series of MODIS 16-Day L3 Global 250m (MOD13Q1) satellite imagery (Land 3 Processes Distributed Active Archive Center and the National Aeronautic and Space 4 Administration with final MODIS data products processed/re-formatted by CSIRO Marine and 5 Atmospheric Research using the MODIS Reprojection Tool ('mrtmosaic', 'resample')). The 6 MODIS product used was Normalized Difference Vegetation Index (NDVI) for the 5 year period 7 from July 2000 to July 2005 covering the Australian continent. A time series of f* at a monthly 8 time step was produced from the NDVI data using a linear function, following Roderick et al. 9 (1999) and Berry & Roderick (2002), but with NDVI endpoint values specific to the MODIS 10 11 imagery calibrated for bare soil. f * 1.118 NDVI * 0.168 where NDVI * 0.15 (6) 12 and f * 0 where NDVI * 0.15 13 Following the calculation of PG* (mol CO2 m-2 day-1) for each 250 m grid cell for the 60 month 14 time-series of f, we calculated GPP for each calendar month and then computed annual sums of 15 GPP (mol CO2 m2 yr-1) for the five years commencing in July 2000. 16 17 References 18 Berry SL, Roderick ML (2002) Estimating mixtures of leaf functional types using continental- 19 scale satellite and climatic data. Global Ecology and Biogeography, 11, 23-40. 20 21 Roderick ML (1999) Estimating the diffuse component from daily and monthly measurements of global radiation. Agricultural and Forest Meteorology, 95, 169-185. 13 1 Roderick ML, Noble IR, Cridland SW (1999) Estimating woody and herbaceous vegetation cover 2 from time series satellite observations. Global Ecology and Biogeography Letters, 8, 501- 3 508. 4 Roderick ML, Farquhar GD, Berry SL, Noble IR (2001) On the direct effect of clouds and 5 atmospheric particles on the productivity and structure of the vegetation. Oecologia, 129, 6 21-31. 7 14 1 Appendix 5: Biomass carbon model coefficients 2 Coefficients for factorial combinations of vegetation, topography and geology in Table 4. 3 Factor classes are described in Table 2. 4 1. Values of the regression constant a: geol 1 2 3 4 veg topo 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 Total Biomass 2 3 9.10 6.78 9.08 8.61 7.64 9.09 6.77 9.07 8.60 7.63 8.90 6.58 8.88 8.41 7.44 9.05 6.73 9.03 8.56 7.59 9.76 7.43 9.74 9.26 8.30 9.75 7.43 9.73 9.26 8.29 9.56 7.23 9.54 9.06 8.10 9.71 7.39 9.69 9.22 8.25 Living Biomass 2 3 8.28 7.14 9.30 8.99 8.03 8.25 7.11 9.27 8.96 8.00 8.06 6.92 9.08 8.77 7.81 8.19 7.05 9.22 8.91 7.94 9.33 8.19 10.36 10.05 9.08 9.30 8.17 10.33 10.02 9.06 9.11 7.98 10.14 9.83 8.86 9.25 8.11 10.27 9.96 9.00 5 6 2. Values of the coefficient b2: Total Biomass Living Biomass veg 2 3 2 3 topo 1 0.0022 0.0028 0.0014 0.0024 2 0.0003 0.0010 0.0004 0.0014 3 0.0022 0.0028 0.0022 0.0032 4 0.0018 0.0025 0.0019 0.0029 5 0.0015 0.0021 0.0016 0.0026 7 8 15