About Terratree

Terratree Pty Ltd is an environmental consultancy based in Fremantle, Western Australia, specialising in ecological assessment, management and revegetation planning. The company was established in 2012 and services the resources sector, land developers, utilities, state and local governments. Terratree is a network of specialist environmental consultants, all of whom have substantial experience in servicing these sectors.

Terratree ecologists and environmental consultants possess a comprehensive understanding of the environmental regulatory framework and requirements relating to environmental impact assessment and management in Western Australia. This understanding has been gained through extensive experience working in industry, environmental consulting, and government environmental regulatory agencies.

At Terratree, we make every effort to avoid unnecessary delays and minimise the cost of environmental assessment and approvals for our clients. The team at Terratree takes a pragmatic, outcome-based approach to ecological assessment. Field surveys are designed to collect the correct data as safely and efficiently as possible. We take pride in the quality and integrity of our reports which incorporate the latest in ecological research and environmental impact assessment techniques. We have substantial relevant experience in liaising with regulatory agencies and developing strong relationships with stakeholders.

Mission and Values

Terratree’s mission is to provide appropriate and accurate environmental consulting services and advice to our clients based on a clear understanding of environmental legislation, regulatory guidelines and relevant biological science.

The Core Values which Terratree operate under are:

  • To run our business professionally and with integrity
  • To be respectful, honest and ethical in all our activities
  • To be a good corporate citizen by supporting the community in which we operate
  • To strive for continual improvement through professional development, research, adaptive management and innovation
  • To promote the principles of sustainable development


Director and Principal Ecologist, Joseph Grehan

Post Grad Dip (Env Mgt) BSc. (Env Science) Advanced Cert. Land Management

Joe is the Principal Ecologist at Terratree Pty Ltd and has over ten years of experience in delivering professional advice to both public and private sector clients. He is an experienced environmental consultant with specialist skills in environmental impact assessment and management planning, botanical surveys (EPA Level 1 & 2) as well as Phytophthora Dieback detection, diagnosis, mapping, and management planning. He has gained substantial experience in environmental impact assessment, management planning, and coordinating regulatory approvals for resource and land development projects throughout Western Australia. During his career, Joe has worked in senior roles including Practice Leader of Ecology at Cardno, Senior Environmental Advisor at Iluka Resources Ltd, and Project Coordinator at the Environmental Management Branch of the Department of Environment and Conservation.

Terratree works with a team of qualified consultants depending on the project being completed.


There are currently no vacancies available at Terratree. However, if you are interested in working with us, please get in touch using our Contact Us page.