Big Tree Registry

Photo by Alex Harris /
Raincoast Conservation Foundation.

Big Tree Registries are community-science driven initiatives that not only raise awareness about the importance of healthy trees and forests but also help identify areas of high conservation priority, providing valuable information to encourage the protection of iconic trees.

Pender Islands Big Tree Registry

The Pender Islands Big Tree Registry was launched in September 2019 aims to raise awareness about the rare and endangered status of Coastal Douglas-fir (CDF) forests and associated ecosystems characteristic to the Gulf Islands. It is a growing database of the big trees found around North and South Pender Islands, with plans to expand to additional southern Gulf Islands in late 2021. The registry has been modelled, with permission, after the University of British Columbia’s (UBC) big tree registry.

The CDF biogeoclimatic zone is among the most biodiverse zones in the province. It is also the most degraded. It is the least-protected zone in BC with less than 1% of its forests remaining as old growth and less than 10% older than 120 years.

Contribute to the Pender Islands Big Tree Registry

Like other big tree registries, trees are nominated by community members who collect species information along with a few simple measurements including trunk diameter at breast height (DBH), height, and crown spread. Nominations are made using the iNaturalist smartphone app, a Google Form submission, or manually using a prepared datasheet (PDF) depending on the nominator’s preference. These nominations are then verified by a qualified professional working with Raincoast Conservation Foundation to ensure measurements and location information have been accurately recorded. Findings will be used to document the biodiversity on Pender Islands and data may be useful for a number of potential projects.

For more information on big tree registries on the Gulf Islands or to submit your manual nomination forms, contact .

We currently are running a contest in collaboration with Nerdy About Nature and Patagonia where you have a chance to win a great prize pack filled with nifty tools to measure big trees.

Measurement guidelines

For more information on how to measure big trees, including tools you will need, photography tips, safety information, and how to measure irregular trees use Raincoast’s big tree measurement guidelines. 

Other registries

Find out about other registries from other regions.

Mother Trees and mycorrhizal fungi on Pender Island

Sep 26, 20227 min read
Projects like Raincoast’s Pender Islands Big Tree Registry (PIBTR) have been initiated in an effort to safeguard big trees and biological diversity in this region.

Tree projects across BC are coming together to advance research objectives and protections

May 5, 20227 min read
These local giants inspire connection to forests, and nature, and encourage people to reflect on their relationships with the land more broadly. 

The Pender Islands Big Tree Registry is helping property owners connect with the forest

Feb 1, 20224 min read
We asked one property owner to share her experience with the Big Tree Registry.

Conserving endangered Gulf Islands forests

Jan 7, 20222 min read
The Coastal Douglas-fir (CDF) bio-geoclimatic zone is the smallest and most endangered of 16 such zones in British Columbia. According to BC’s Conservation Data Centre, nearly every ecological community in the CDF is provincially listed as threatened or endangered. The Gulf Islands represent 33.2% of CDF forests and associated habitats, and are the Traditional Territories…

Ethics of making the location of big trees accessible to the public

Sep 1, 20217 min read
The benefits and implications of unrestricted access to tree location need to be carefully considered.

Interview: Big tree registries, BC’s logging practices and Nerdy about Nature

Aug 30, 202112 min read
We posed some questions to Ross Reid, of Nerdy about Nature, so you can get to know him better.