Dendroecology and Dendroclimatology of a Tasmanian bog forest

Dendroecology and Dendroclimatology of a Tasmanian bog forest Daniel J. Balanzategui, Carolyn A. Copenheaver, David C. Frank, Liya Jin, Nicolas Latte, Mauro Monteiro, Zhiyuan Shang, Franziska Slotta, James H. Speer, Alexander “Zan” Stine and Jen A. Wilkinson

Introduction Tasmanian montane bog forest �microhabitat for climate sensitive species �contributes to regional diversity Limited understanding of forest dynamics and climatic influences

Objectives Explore the wood anatomy of all species on the site Reconstruct the demographic structure and stand dynamics of a mature Tasmanian bog forest Compare the dendroclimatic response of King Billy Pine and Celery Top Pine

Study Area Magg’s Mountain in northern Tasmania West of Lake Rowal (41. 71 °S, 146. 19 °E, 800 masl) Publically-owned and managed forestland Cool climate montane mature bog forest Dominant species: King Billy Pine (Athrotaxis selaginoides), Celery Top Pine (Phyllodladus aspleniifolius), Tea Tree (Leptospermum sp. ), Myrtle (Nothofagus cunninghamii)

Field methods 38 trees sampled along a belt transect additional King Billy Pine, Celery Top Pine, and Tea Tree (N=25) were cored from outside of the plot to increase sample size of these species 10 cross sections

Sample design 4 m 50 m All trees > 4 cm Diameter at breast height 3 cores (2 at 0. 3 m and 1 at 1. 3 m) Species All trees > 30 cm Diameter at breast height 3 cores (2 at 0. 3 m and 1 at 1. 3 m) Species

Sample preparation Cores were glued on wooden core holders Sanded with progressively finer sand paper Characteristics of wood anatomy were studied

Laboratory Methods Skeleton plot Cores dated prior to measuring Narrow rings used for the list year method of visual crossdating Skeleton plot for dating samples with missing outermost rings

Laboratory Methods Crossdating was verified with COFECHA Chronologies of King Billy Pine and Celery Top Pine were detrended by a 30 -year spline in ARSTAN Climate analyses were conducted in RStudio and MATLAB Growth releases and suppressions were identified with the radial growth averaging criteria developed by Nowacki & Abrams

Data Analyses Growth release %growth change year X = (ave. 10 prior years – ave. 10 following years) x 100 ave. 10 following years Criteria: at least 10 years in a row with %growth change ≥ 25 % Growth suppression %growth change year X = (ave. 10 prior years – ave. 10 following years) x 100 ave. 10 following years Criteria: at least 10 years in a row with %growth change ≤ -25 %

King Billy Pine Athrotaxis selaginoides Annual ring Late wood Early wood

Celery Top Pine Phyllocladus aspleniifolius Annual ring Late wood Early wood

Tea tree Leptospermum sp. Annual ring

Myrtle Nothofagus cunninghamii Annual ring

Waratah Telopea trunctata Annual ring

Results - Dendroecology 50 45 40 35 30 25 20 15 10 5 0 -2 -1 0 1 2 Sample distribution along transect

m 5 c -4 41 m 0 c -4 36 m 5 c 31 -3 m cm -3 0 26 5 c 0 -2 200 21 400 -2 0 c m 600 16 800 -18 12 -18 18 2 23 2 -1 18 832 33 -1 18 842 43 -1 18 852 53 -1 18 862 63 -1 18 872 73 -1 18 882 83 -1 19 892 93 -19 19 02 03 -1 19 912 13 -1 19 922 23 -1 19 932 33 -1 19 942 43 -1 19 952 53 -1 19 962 63 -1 19 972 73 -1 19 982 83 -1 19 992 93 -2 01 2 13 18 03 18 Number of trees 6 1115 cm 1000 cm 1200 610 5 c m 0 - Stems per hectare Results - Dendroecology Age class distribution 5 4 3 2 1 Stems too small to include in study 0 Size class distribution Stems too small to include in study NOTHOFAGUS CUNNINGHAMII PHYLLOCLADUS ASPLENIIFOLIUS TASMANNIAN LANTIALA ATHROTAXIS SELAGINOIDES LEPTOSPERMUM SP. TELOPIA TRUNCATA

Results - Releases Percent of trees with release events 100 90 80 70 60 50 40 30 20 10 0 1820 1830 1840 1850 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 ATHROTAXIS SELAGINOIDES King Billy Pine NOTHOFAGUS CUNNINGHAMII Celery Top Pine

70 Decade King Billy Pine (light blue) and Celery Top Pine (dark blue) 80 20 00 20 10 90 19 19 70 19 60 19 50 19 40 19 30 19 20 19 10 19 00 19 90 80 18 18 18 60 50 18 18 30 40 18 18 20 18 Percent of trees with release events Results - Suppressions 100 90 80 70 60 50 40 30 20 10 0

CLIMATE: Raw data Crossdated series Celery Top (23 cores / 15 trees) King Billy (22 cores / 13 trees)

Raw data: King Billy Vs. Celery Top

Climate: Detrending Series detrending with arstan (spline 30 years cutoff)

Standard indices King Billy Vs. Celery Top Standard

Climate data Monthly climate data Regionally-averaged Tasmanian weather stations (1911 -2009 )

Climate correlation: Celery Top Precipitation

Climate correlation: King Billy Precipitation

Climate correlation: Celery Top Maximum temperature

Climate correlation: King Billy Maximum temperature

Conclusions The Tasmanian bog forest established as a stand in the early 1800`s After establishment, there was a period of high competition and few new trees started growing Currently, the forest has frequent, local disturbance events

Conclusions Tree-ring width is positively correlated with the previous year`s precipitation, particularly in Celery Top Pine Tree-ring width is negatively, correlated with the previous year`s temperature In Celery Top Pine, tree-ring width is positively correlated with temperature from 2 years earlier