Empirical equations for dry biomass of trees and their components for Scots pine growing in various stocking

Size: px

Start display at page:

Download "Empirical equations for dry biomass of trees and their components for Scots pine growing in various stocking"

Annice Benson
6 years ago
Views:

1 Empirical equations for dry biomass of trees and their components for Scots pine growing in various stocking Karol Bronisz, Szymon Bijak, Agnieszka Bronisz, Maciej Czajkowski, Łukasz Ludwisiak, Robert Tomusiak, Rafał Wojtan, Michał Zasada Warsaw University of Life Sciences - SGGW Forest Biomass Conference 2013, October 7-9, 2013, Mierzęcin, Poland

2 Rationale/Background Biomass and carbon sequestration has recently become quite important issue. It is essential to have a tool that enables the estimation of amount of carbon accumulated in trees and forests. Empirical allometric equations allow determining dry biomass of trees and their parts on the basis of tree characteristics (e.g. height and diameter).

Objective Elaboration of system of aboveground biomass equations based on data from old Scots pine stands (81-100 years old) with varying density.

3 Objective Elaboration of system of aboveground biomass equations based on data from old Scots pine stands ( years old) with varying density. Compare this system with existing equations for Scots pine based on different empirical material. Assessment of biomass of Scots pine trees and stands from western Poland.

4 Study site development of biomass equations system Drawno Forest District 5 pine stands with varying density 50 felled and weighted trees 10 in each stand Biomass of: stem, small, thick and dead branches, cones, needles

5 Study site existing biomass equations Gubin and Lubsko Forest District 18 pine stands 90 felled and weighted trees Biomass of: wood, bark, live and dead branches, branches with needles

6 Study sites Drawno Lubsko and Gubin We are here

7 Material - Drawno Stocking class Number Sample trees Dbh (cm) H (m) mean max min mean max min All I II III IV V

8 Methods - Drawno Investigate the relationship between the various parts of the tree biomass and various independent variables (dbh - D and height - H). Search for function that describes the relationship between the independent variables and biomass (W) the best. W = b 0 D^b 1 [1] W = b 0 H^b 1 [2] W = b 0 D^b 1 H^b 2 [3] W = b 0 D^2 H ^b 1 [4] W = b 0 D^2 H^2 ^b 1 [5]

9 Methods - Drawno Equations parameterization nonlinear least-squares estimation residual standard error RSE Akaike s Information Criterion Coefficient of determination independent variables usually obtained during the measurement of forest minimum number of parameters necessary to obtain a satisfactory result

10 Methods - Drawno Equations parameterization Total aboveground biomass of a tree can be estimated directly from dbh and height or by summing estimates of biomass of individual tree components. Logical condition - sum of the estimated biomass of tree parts match the estimated total tree biomass assuring the additivity of the biomass equations. Seemingly Unrelated Regression (SUR)

11 Methods - Drawno Calculations and analyzes were performed using the systemfit and nlme packages in R environment

12 Methods Lubsko and Gubin Photo: Karol Bronisz Photo: Karol Bronisz

13 Methods Lubsko and Gubin Photo: Karol Bronisz

14 Methods Lubsko and Gubin nonlinear least-squares estimation (Zasada et al. 2008) root mean squared error (RMSE) Akaike s Information Criterion (AIC) coefficient of determination (R 2 ) mean error (ME) independent variables usually obtained during the measurement of forest minimum number of parameters necessary to obtain a satisfactory result seemingly unrelated regression (SUR) Zasada M. Bronisz K. Bijak S. Wojtan R. Tomusiak R. Dudek A. Michalak K. Wróblewski L Wzory empiryczne do określania suchej biomasy nadziemnej części drzew i ich komponentów. Sylwan

15 Results - Drawno Estimates of parameters in equations for stem biomass Equation AIC R 2 RSE W = b 0 D^2 H^2 ^b 1 [5]

16 Results - Drawno Estimates of parameters in equations for needles biomass Equation AIC R 2 RSE W = b 0 D b 1 [1]

17 Results - Drawno Estimates of parameters in equations for small branches and cones biomass Equation AIC R 2 RSE W = b 0 D 2 H b 1 [4]

18 Results - Drawno Estimates of parameters in equations for thick branches biomass Equation AIC R 2 RSE W = b 0 D b 1 H b 2 [3]

19 Results - Drawno Estimates of parameters in equations for dead branches biomass Equation AIC R 2 RSE W = b 0 D b 1 H b 2 [3]

20 Results - Drawno Finally: Wdrs = b 0 D 2 H 2 b 1 Wis = b 2 D b 3 Wdgs = b 4 D 2 H b 5 Wggs = b 6 D b 7 H b 8 Wsgs = b 9 D b 10 H b 11 stem needles small branches and cones thick branches dead branches WAlls = Wdrs + Wis + Wdgs + Wggs + Wsgs Total aboveground biomass

21 Results - Drawno parameters: Stand b0 b1 b2 b3 b4 b5 All I II III IV V b6 b7 b8 b9 b10 b11 All I II III IV V

22 Results biomass in Drawno % dead br. thick br. small br.&cones needles stem Alls I II III IV V Stand

23 Results - total aboveground biomass (kg) Theoretical values: Dbh = cm H =15 m Lubsko&Gubin Drawno Dbh (cm)

24 Results - total aboveground biomass (kg) Theoretical values: Dbh = cm H = 20 m Drawno Lubsko&Gubin Dbh (cm)

25 Results - total aboveground biomass (kg) Theoretical values: Dbh = cm H = 25 m Drawno Lubsko&Gubin Dbh (cm)

26 Conclusions Differences between biomass estimates in Drawno and Lubsko&Gubin. Those differences depend mainly on tree height. No influence of stand density on calculated biomass allocation for old Scots pine stands. The need to know the history of the stand in order to assess the impact of density on biomass allocation.

27 T H A N K Y O U F O R Y O U R A T T E N T I O N! contact: karol.bronisz@wl.sggw.pl

Comparability of Scots pine biomass functions in Baltic and Nordic countries

The Nordic-Baltic-EFINORD Co-operation group for forest inventory. Mariehamn, 2/3 9 215 Comparability of Scots pine biomass functions in Baltic and Nordic countries Gintaras Kulbokas, Andrius Kuliešis