ISA TRAQ case studies

ISA TRAQ · Put your knowledge to work in context.

The ISA Tree Risk Assessment Qualification (TRAQ) is a credential offered by the International Society of Arboriculture, the body whose credential pages describe ISA credentials as helping "consumers identify qualified, knowledgeable tree care professionals." TRAQ sits among the ISA credential types aimed at people who want to advance a career in arboriculture, and it is built around a single practical skill: judging the likelihood and consequences of tree failure and communicating that judgment to whoever owns or manages the tree. Candidates typically include consulting arborists, municipal and utility vegetation managers, insurance and legal reviewers, and crew leaders who sign off on hazard work. The ISA TRAQ case studies are 5 cases and about 4,573 words.

White oak with active butt-rot conks beside a picnic table

A 22 m tall white oak (Quercus alba), 85 cm DBH, grows in mowed turf in a public park. On the north side of the root flare, at and slightly below grade, there are three fresh Inonotus dryadeus conks, one of which is exuding amber droplets.

981 words, about 5 min 2

Cracked codominant union over a school sidewalk before a forecast wind event

A 14 m tall Norway maple (Acer platanoides), 45 cm DBH, stands in a 1.2 m turf strip between a 2.4 m public sidewalk and the street, directly in front of an elementary school. At 2.5 m the trunk forks into two codominant stems of nearly equal diameter, with a pronounced bark ridge and included bark running into the union.

940 words, about 5 min 3

Beech with directional crown symptoms before a driveway excavation inside the root zone

A 70 cm DBH European beech (Fagus sylvatica), 19 m tall, stands 11 m from a two-storey house in a residential garden. The owner has approval to build a driveway along the west side of the tree, passing 3 m from the trunk and requiring a 25 cm excavation over roughly 40% of the tree's root zone; delivery vehicles and a plate compactor will work in the same area.

906 words, about 5 min 4

Freshly uprooted birch above a busy trail, with a second leaning tree for contrast

After 100 mm of rain in 48 hours, a 48 cm DBH yellow birch (Betula alleghaniensis), 17 m tall, is leaning about 18 degrees from vertical, downhill toward a paved multi-use trail. On the uphill side, 2.5 m from the trunk, there is a crescent-shaped crack in the soil with a 10 cm raised lip behind it, and one root is visibly pulled and splintered at the crack.

860 words, about 4 min 5

Canary Island date palm with a basal conk and a proposal to chisel it off

At a resort, a 9 m tall Canary Island date palm (Phoenix canariensis) with a 65 cm trunk stands 1.5 m from a 1.2 m wide concrete walkway used by roughly 600 guests a day, with a valet podium 4 m away staffed 16 hours a day. At the base, about 20 cm above grade on the east side, there is a single shelf-shaped conk with a brown edge, roughly 15 cm across.

886 words, about 4 min