AFTER THE STORM DISPUTING SOME COMMON TREE FAILURE BELIEFS

AFTER THE STORM DISPUTING SOME COMMON TREE FAILURE BELIEFS

I began my arboriculture career working for my dad at the age of 16. I am ASCA RCA #633. I have been a Certified Arborist for over ten years. I have been TRAQ d for over 5 years. I am also a Municipal & Utility Specialist, CTW and a Board Member of the PNWISA I have pruned, removed and assessed thousands of trees and have assessed thousands of tree failures for the PNWTFD and the CTFD.

PNWTFD The Pacific North West Tree Failure Database was officially started in 2017. We collect data from all the areas that are represented in the PNW-ISA. So far we have collected over 2,000 tree failure reports. Most reports have come from the lowland Puget Sound area of WA but we are also getting many reports from the Portland OR metro area, Corvallis OR, Victoria B.C., Vancouver B.C. and Bend, OR. 3

WHICH TREE DO YOU THINK THE PNWTFD HAVE THE MOST TREE FAILURE REPORTS OF? Acer macrophylum, bigleaf maple Alnus rubra, red alder Arbutus menziesii, madrone Populus trichocarpa, black cottonwood Pseudotsuga menziesii, Douglas fir Go to: www.menti.com Enter Code: 30 50 35 4

COMMON TREE BELIEFS OF EUCALYPTUS Nothing grows under Eucalyptus trees Eucalyptus tree kill native short-beaked CA birds through beak gumming Birds can not nest in Eucalyptus trees because their nests slip off the smooth bark Eucalyptus tree are extremely invasive and should be cut down Eucalyptus trees explode in fires Eucalyptus trees fail more then other trees (third most reported genera of tree failures by CTFD. Reported half as often as Quercus) 5

I DON T MIND WHEN COTTONWOODS GET REMOVED Cottonwood trees are demonized to the extent Eucalyptus trees were in California. They are said to be weak and weedy trees which are very susceptible to wood decay organism infection and that they don t compartmentalize well. They also have a reputation for sidewalk lifting and branch failure. Many of these branch failures occur during warm weather and are attributed to Sudden/Summer Limb Drop. 6

COTTONWOOD FACTS July Acer macrophyllum 25 Alnus rubra 8 Liquidambar styraciflua 7 Salix sp. 6 Populus trichocarpa 5 Black Cottonwood Branch Failures August Acer macrophyllum 22 Alnus rubra 17 Liquidambar styraciflua 7 Pseudotsuga menziesii 6 Arbutus menziesii 5 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Populus trichocarpa Branch September Acer macrophyllum 32 Alnus rubra 21 Populus trichocarpa 12 Pseudotsuga menziesii 10 Robinia pseudoacacia 6 7

MADRONES ARE BOMB PROOF Madrones are a beloved native species that are not doing well in adapting to our changing environment What I have heard arborists say Madrones are bomb proof and nothing can knock them down. I have heard people say that they have never seen a madrone fail and that a dead madrone can stand forever. What I have seen Madrones fail regularly. The ones which I have seen fail are often close to trails within natural areas. Most of the failures that I have seen are root failures or codominant stem failures. They often involve decay organisms and extensive wood decay. Most live madrone failures that I have seen occur in storms. Many madrones failed in the February 2017 Snowstorm. I have seen dead trees fail any time. I have seen many madrone snags fail. 8

Results from Mentimeter 9

DATA ON MADRONE FAILURES Madrone Failures by Date Madrone vs. Other Species Failures Acer macrophyllum 391 Alnus rubra 252 Pseudotsuga menziesii 92 Arbutus menziesii 90 Populus trichocarpa 83 Tsuga heterophylla 38 Salix sp. 35 Cedrus deodara 34 Feb Mar May Jun Aug Oct Nov Jan Feb Mar Apr May Aug Sep Oct Nov Dec Feb Mar Apr Jun Jul Oct Nov Dec Branch Root Stem Arbutus menziesii Thuja plicata 32 Pinus monticola 32 10

MADRONE DISORDERS Madrone are not dealing well with urbanization Madrone twig dieback, Botryosphaeria dothidea and madrone canker, Neofusicoccum arbuti which effect the branches of madrone Several species of Phytopthora cause root or collar rot on the trunks or roots. Madrone are also susceptible to Armillaria sp. and Heterobasidion occdentale. 11

IT DIDN T FALL OVER IN LAST YEARS STORM Tree failures cascade. At some point in time a change in structural stability occurs which weakens a point on the tree and the whole thing begins to progressively fail. This failure can happen fast or slow. The change in structural stability can be many unpredictable things including a small break in wood due to torsion forces in the wind or a tiny piece of wood being devoured by a wood decay organism. Just because a tree with stood some forces before is not guarantee that it will continue to do so. 12

WHAT IS YOUR TREE RISK ASSESSMENT BIAS? Retain trees Removed trees Be apathetic Go to: www.menti.com Enter Code: 30 50 35 13

IT WAS ROTTEN, Y ALL SHOULD HAVE KNOWN? 14

What is the answer to trees and decay? Majority of trees in the PNWTFD are in good condition Know your trees and know your decay Understand that there are benefits and negatives associated with rotten trees Accept that you may be inadequate and may have a bias Be impartial, unbiased, do what another arborist would do and not rely on snap judgements or common knowledge Every situation and trees is unique Don't make a situation worse though your pruning and consider retrenching a god damn tree before removing it TREE FAILURES BY CONDITION 18% 20% 25% 37% Dead Fair Good Poor

Results from Mentimeter 16

IT WAS A LOW RISK TREE 17

IT WAS A LOW RISK TREE 18

THIS TREE FAILURE OCCURRED DURING A STORM AND TRA ARE ONLY GOOD DURING NORMAL WEATHER TRAQ Form has you to consider the Common Weather when performing an TRA. Common Weather: Regular occurring climatic conditions that trees adapt to. 2 nd Edition TRAQ Manual, consider normal storms and extreme storms not abnormally extreme storms. Normal storms occur several times during defined time frame and affect most trees in the area. Extreme storms occur less frequently and may impact a smaller portion of the region (thunderstorms, accumulations of freezing rain, and straight-line winds). 110 King County storms record by NOAA in the last 30 years, Only 6 storms in Seattle which had over 50 kts per hour winds in last 30 years. Anything above that is not an act of god, its just not what a industry standard TRA covers. 19

WHAT CAUSES TREES TO FAIL 1: Weather forces (wind, rain, snow) 2: Soil failure (steep slopes, super saturation) 3: Structural defects (lean, co-dominate attachments) 4: Decay organisms present 20

TREE FAILURES BY MONTH 21 0 50 100 150 200 250 May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 Jan-16 Feb-16 Mar-16 Apr-16 May-16 Jun-16 Jul-16 Aug-16 Sep-16 Oct-16 Nov-16 Dec-16 Jan-17 Feb-17 Mar-17 Apr-17 May-17 Jun-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Nov-18 Failures by Month

QUESTIONS? Go to: www.menti.com Enter Code: 30 50 35 22

THANK YOU Christopher.rippey@gmail.com www.southsoundarborist.com www.pnwtreefailuredb.com