The impact of competition for growing space to diameter, basal area and height growth of trees

Transcription

1 The impact of competition for growing space to diameter, basal area and height growth of trees Authors: E. Linkevičius, A. Kuliešis, Aleksandras Stulginskis University H. Röhle, Technische Universität Dresden J. Schröder, Eberswalde Forest Research Station M. Aleinikovas Lithuanian Research Centre for Agriculture and Forestry, Institute of Forestry. 1

2 Contents Introduction Materials and methods Results Conclusions 2

3 Introduction Aim of the research: To compare distance dependent and distance independent competition indices and find the best ones with highest predictive capacity to simulate basal area and height growth of pine trees under Lithuanian conditions. To describe the impact of growth dependent competition to tree diameter and height growth of pine trees. 3

4 Introduction Hypothesis: Distance dependent competition indices had higher partial correlation with tree basal area and height increment than distance independent competition indices. Growth dependent competition has negative effect to tree diameter and height growth of pine trees in Lithuania. 4

5 Materials and methods Experimental data: 18 experimental plots used for analysis, established in

6 Materials and methods Plots were re-measured 6 times. Data collected: Tree diameter at breast height (d), Tree height (h), Height to crown base (hcb), Crown width (cw), Coordinates of each tree (X, Y). 6

7 Materials and methods Analysis of competition for growing space Competitor selection methods tested. Height to crown base 80 degrees (HCB80) Height to widest crown width 60 degrees (HWCW60) Stem base 60 degrees (SB60) 7

8 Materials and methods Analysis of competition for growing space Distance independent competition indices tested: WYKOFF et al. (1982) CI 1 Kj j1 BAL HEGYI (1974) CI 2 Kj j1 d d j i Where: BAL=basal area of larger trees cm 2, K=number of trees per plot, i=subject tree, j=competitor(s), d=diameter at breast height cm 2, dist ij =distance between competitor and target trees m. 8

9 Materials and methods Analysis of competition for growing space Distance dependent competition indices tested: HEGYI (1974) BIGGING & DOBBERTIN (1992) BIGGING & DOBBERTIN (1992) Where: K=number of trees per plot, i=subject tree, j=competitor(s), d=diameter at breast height cm 2, dist ij =distance between competitor and target trees m, hca=tree horizontal crown area m 2, cv=crown volume m 3, SH=height of intersection of search cone and tree axis. CI 3 CI 4 CI 5 Kj j1 Kj j1 Kj d j 1 i hca cv cv d j ( dist j hca i j SH i SH ij 1) 9

10 Materials and methods Analysis of competition for growing space Distance dependent competition indices tested: PRETZSCH (1992) SCHRÖDER (2004) Kj 6 j1 Kj NAGEL (1999) CI 8 hca j ( HWCW i ) j1 Where: K=number of trees per plot, i=subject tree, j=competitor, dist ij =distance between competitor and target trees m, hca=tree horizontal crown area m 2, SH=height of intersection of search cone and tree axis, β =gradient of straight line connecting base of search cone and top of competitor tree, vca=vertical crown area m 2, HSCB=height of search-cone base, HWCW=height of greatest crown width in 66% of subject tree height m. 10 CI CI 7 Kj j1 hca vca vca i j ( HSCBi ) j hca i ( dist ij 1)

11 Materials and methods Analysis of competition for growing space VCA j1 VCA j2 80 VCA i H CB i dist SCHRÖDER (2004) 11

12 Materials and methods Analysis of competition for growing space Establishing the buffer zones in each plot. 46 m 0 The impact of competition was evaluated by partial correlation analysis in each experimental plot and inventory. Mean results presented. 46 m 12

13 Materials and methods The impact of growth dependent competition to tree diameter and height growth of pine. While analyzing the impact of competition to tree diameter growth, trees were grouped according to competition values to intervals with step of 2, (0; 2], (2; 4], (4; 6].... While analyzing the impact of competition to tree height growth, interval length till its value 4 was equal to 1, then it continued with step of 2, (0; 1], (1; 2], (2; 3], (3; 4], (4; 6]... For each interval, mean values were found. 13

14 ln(1+ci 4 ) Res 2 Results Main relations of partial correlation y = -4,6872x + 11,118 R² = 0, y = 0,0272x - 0,9796 R² = 0,5305 i ba, cm i ba, cm ,0 1,0 2,0 3,0 ln(1+ci 4 ) ba, cm 2 3 y = -0,0045x + 2,3099 R² = 0, y = -0,0714x + 0,0131 R² = 0, ba, cm Res 1 14

15 Mean partial r value Results The partial impact of competition to influence mean annual periodic basal area increment. 0,1 HCB 80 CI4 HCB 80 CI5 0,05 HCB 80 CI6 HCB 80 CI7 i ba =f(ba) mean R ,05-0,1 HWCW 60 CI7 SB 60 CI5 HCB 80 CI8 HWCW 60 CI3 HWCW 60 CI4 HWCW 60 CI8 SB 60 CI7 HCB 80 CI3 SB 60 CI4 SB 60 CI3 SB 60 CI6 HWCW 60 CI6-0,15 HWCW 60 CI5 SB 60 CI8-0,2 HCB80 CI 4 CI2 CI1 15

16 Significant cases from all cases Results The partial impact of competition. Significant cases from all cases. 45% 40% 35% 30% 25% HCB80 CI 4 HCB 80 C4 HCB 80 C6 SB 60 CI6 HWCW 60 CI7 SB 60 CI5 HCB 80 C5 HCB 80 C7 HWCW 60 CI6 HWCW 60 CI8 SB 60 CI7 20% HCB 80 C8 HCB 80 C3 15% HWCW 60 CI3 SB 60 CI4 10% 5% 0% HWCW 60 CI4 HWCW 60 CI5 CI2 SB 60 CI3 SB 60 CI8 CI1 16

17 Mean partial r value Results The partial impact of competition to influence mean annual periodic height increment. i h =f(h) mean R ,1 0,05 0-0,05-0,1-0,15 SB60 CI 4 CI2 SB 60 CI4 SB 60 CI5 SB 60 CI3 SB 60 CI6 HCB 80 CI7 SB 60 CI7 HCB 80 CI6 HCB 80 CI5 HCB 80 CI3 CI1 HCB 80 CI4 HWCW 60 CI6 HWCW 60 CI7-0,2-0,25-0,3 HWCW 60 CI4 HWCW 60 CI3 HCB 80 CI8 HWCW 60 CI5 HWCW 60 CI8 SB 60 CI8 17

18 Significant cases from all cases Results The partial impact of competition. Significant cases from all cases. 30% 25% 20% SB60 CI 4 CI2 SB 60 CI4 SB 60 CI5 SB 60 CI3 SB 60 CI6 HCB 80 CI7 SB 60 CI7 HCB 80 CI6 15% HCB 80 CI5 CI1 HCB 80 CI3 HCB 80 CI4 10% HWCW 60 CI6 HWCW 60 CI7 HWCW 60 CI4 HWCW 60 CI5 5% HWCW 60 CI3 HWCW 60 CI8 0% HCB 80 CI8 SB 60 CI8 18

19 Results naudojami geriausi rysiai The impact of growth dependent competition to tree diameter and height growth of pine. 1 0,8 y = -0,335ln(x) + 1,2656 R² = 0,9863 1,0 0,8 y = x 1- e - x ,6 0,6 R 2 = ,4 0,4 0,2 0, , HCB80 CI 4 SB60 CI 4 19

20 Conclusions While modeling periodic mean annual tree basal area incrementint, competitor selection method HCB 80 combined with competition index CI 4 showed the best results. While modeling periodic mean annual tree height increment, distance independent competition index CI 2 showed the best results and outcompeted all distance dependent competition indices. 20

21 Conclusions Competition has only negative impact to tree diameter growth. With increasing competition tree diameter increment only decreases. Small amount of competition increases tree height growth. However, stronger competition have negative impact to tree height growth as well. 21

22 THANK YOU FOR YOUR ATTENTION!!! 22