Comparability of Scots pine biomass functions in Baltic and Nordic countries

Transcription

1 The Nordic-Baltic-EFINORD Co-operation group for forest inventory. Mariehamn, 2/ Comparability of Scots pine biomass functions in Baltic and Nordic countries Gintaras Kulbokas, Andrius Kuliešis Lithuanian State Forest Service web: Aleksandras Stulginskis University web:

2 Relevance of aboveground biomass functions comparability Reliable tree biomass data provided by different sources is one of the most important prerequisites for: successful forestry efficiency analysis, planning of sustainable forest resources use, comparable carbon budget estimation and monitoring in forest. The data of study can be used for: analysis of tree biomass data provided by European NFI (project SC13), improvement of European Dynamics Model EFDM (SC14, SC15), development of compatible set of biomass equations (Diabolo Task T2.2) 2

3 The goal of study The goal of the study is to evaluate the comparability of Scots pine trees aboveground biomass and its components, estimated by various tree level functions, which can be used in NFI of Nordic and Baltic countries 3

4 Aboveground tree biomass structure used in study Tree AGB Crown Stem Green branches Dead branches Stem bark Stem wood Foliage (leaves, needles) 4

5 Biomass functions used for study 47 various tree level functions (1 publications) from 3 countries were used for study. Biomass of Albrektso n et al., 1984 Briggs & Cunia, 1982 (1) Briggs & Cunia, 1983 (2) Hakkila, 1991 Korhonen & Maltamo, 199 Mäkelä & Vanninen, 1998 Marklund, 1988 (1) Marklund, 1989 (2) Miksys et al., 27 Repola et al., 27 Sweden Finland Finland Finland Finland Finland Sweden Sweden Lithuania Finland Stem wood SW D, H D D D, H D, H D, H 6 Stem bark SB D, H D, H D D D, H D, H D, H 7 Total stem ST D, H D D, H D, H 4 SST=SW+SB x x x 3 Green branches BR D, H D D, H D D, H D, H 6 Needles NE D, H D D D D D D, H D, H D, H 9 Dead branches DB D D D, H D, H D, H 5 Total crown CR D D, H D D* D, H* D, H 6 SCR=BR+NE+DB x x 2 Total aboveground AB D D D D, H 4 SAB=ST+CR+DB x x x x 4 Total Independent variables of functions: D- tree DBH, H- tree height. SST, SCR, SAB biomass estimated by summary of separate tree part biomass. * - total crown biomass was corrected adding biomass of dead branches. 5

6 The data used for comparison Data for comparison Scots pine trees from 2 5 permanent sample plots of Lithuanian NFI Study object all pine trees in all forest stands of Lithuania stand area ha (34% of country area) mean growing stock volume in all stands 251 m 3 /ha in Scots pine stands 32 m 3 /ha share of pine 32,4% of total stand area 36,6% of total growing stock volume 6

7 1. Comparison of predicted biomass for mean tree in Scots pine stands of Lithuania Mean data in Scots pine stands. NFI 214 Age class* Height, m DBH, cm * 2 age class consist of years old stands 7

8 Biomass, kg dm / tree The estimation of biomass for mean tree in Scots pine stands Albrektson Briggs, 1 Briggs, 2 Hakkila Mäkelä Marklund, 1 Marklund, 2 Mikšys Repola Total crown biomass Needles Dead branches Green branches Age classes Age classes 8

9 Biomass, kg dm / tree The estimation of biomass for mean tree in Scots pine stands 5 Stem bark Stem wood Total stem biomass Age classes Age classes 9

10 Biomass, kg dm / tree The estimation of biomass for mean tree in Scots pine stands Age class Height, m DBH, cm Total aboveground biomass 5 4 Selected functions Age classes 1

11 2. Loess analysis of differences between biomass estimations for Scots pine trees measured in all stands Selected biomass functions: Briggs and Cunia, 1982 Korhonen and Maltamo, 199 Marclund, 1988, 1989 Mikšys et al., 27 Repola et al., 27 11

12 Difference, kg dm / tree The differences of tree crown biomass predicted by various functions comparing with LT estimation. Loess analysis Biomass LT (Mikšys), kg dm / tree 12

13 Difference, kg dm / tree The differences of tree stem biomass predicted by various functions comparing with LT estimation. Loess analysis Biomass LT (Mikšys), kg dm / tree 13

14 Difference, kg dm / tree The differences of aboveground tree biomass predicted by various functions comparing with LT estimation. Loess analysis Biomass LT (Mikšys), kg dm / tree 14

15 The differences of biomass predicted by various functions comparing with LT estimation (Loess curves) Green branches Dead branches Needles Stem bark Stem wood Total aboveground 15

16 3. Estimation of biomass difference by DBH, age and site index H1 16

17 Mean difference from LT (Mikšys), % Mean difference from LT (Mikšys), % The mean tree biomass differences comparing with LT estimation by tree DBH Crown (needles+branches) Stem (bark+wood) > > DBH, cm 1 8 Total aboveground > DBH, cm 17

18 Mean difference from LT (Mikšys), % Mean difference from LT (Mikšys), % The mean tree biomass differences comparing with LT estimation by tree age Crown (needles+branches) Stem (bark+wood) Age, years Total aboveground Age, years 18

19 Difference from LT (Mikšys), % Difference from LT (Mikšys), % The mean tree biomass differences comparing with LT estimation by site index H Crown (needles+branches) > Stem (bark+wood) > H 1, cm Total aboveground > H 1, cm 19

20 Total biomass, Mt dm The prediction of total crown and stem biomass in Lithuania by various functions Crown biomass Stem biomass Briggs, 1 Marklund, 1 Marklund, 2 Marklund, 2 Repola Mikšys Repola Mikšys Korhonen Marklund, standard error 2

21 Total biomass, Mt dm The prediction of total Scots pine tree aboveground biomass in Lithuania Total aboveground biomass Mikšys Briggs, 1 Marklund, 1 Marklund, 2 Repola 1.96 standard error 21

22 CONCLUSIONS Differences of aboveground biomass of Scots pine, predicted using functions of Briggs and Cunia, 1982; Korhonen and Maltamo, 199; Marklund, 1988, 1989; Repola et al., 27 and Lithuanian function (Mikšys et al., 27) do not exceed 2 %. The least differences of predicted biomass comparing with predicted by Lithuanian function was received for stem biomass functions of Marklund, 1989, (1%) and Korhonen and Maltamo, 199 (3%), for total aboveground biomass - by functions of Marklund, 1989 (5%). The bigger differences in biomass were defined for marginal values of tree diameters (up to 14 and more than 38 cm) and ages (up to 4 and more than 12 year). 22

23 Thank you!