Council

Aaron Hirota
President

Aaron is a Principal Landscape Architect and Ontario Practice Lead with Architecture49 in Ottawa. He enjoys working on all facets of the profession especially project management, urban design, parks and open space development. His current interests include heritage and cultural landscapes, accessible and equitable design, and sustainability. Aaron is working on projects in Ottawa and across Eastern Ontario. He is a full member of the Ontario Association of Landscape Architects (OALA) and an out of province member of the Manitoba Association of Landscape Architects (MALA), L’Association des architectes paysagistes du Québec (AAPQ) and the Saskatchewan Association of Landscape Architects (SALA). He graduated from the University of Manitoba with a Bachelor of Environmental Design degree in 1998 and a Masters degree in Landscape Architecture in 2005. Aaron has served on Council since 2021, most recently as Vice President from 2023-2024.

Justin Whalen
Vice-President 

Justin is a Senior Landscape Architect at GSP Group in Kitchener with experience working in a wide range of projects from streetscape and trail designs, residential and industrial developments to wayfinding, parks and recreation and campus master plans. With an eye for detail and excellent communication skills, Justin works effectively with allied professionals, clients, stakeholders and contractors to ensure projects are brought to fruition. He has a strong interest in the design of trails and public spaces, with the intent of creating meaningful spaces to connect people to the places where they play, live and work. As a project manager, Justin leads projects from conceptual design to construction, participating in all stages, from site inventory and analysis, to refining detailed designs and developing working drawing sets. He has a strong skill set in overseeing and directing the implementation of projects through construction administration in order to see ideas become reality.

Justin obtained his Bachelor of Landscape Architecture from the University of Guelph in 2014 and his Full Membership with the OALA in 2018.

Justin has been serving on the OALA Council since 2016, when he was first elected as an Intern Representative, and then to a Councillor position in 2018. Now in his fifth term, he is honoured to continue representing both existing and new members of the OALA membership as Vice President, in addition to working with Council to further advance the profession within Ontario and support the OALA.

Kate Preston
Treasurer

Kate is a senior landscape architect and Partner at Dillon Consulting Limited, with over 22 years of experience in public space design, park revitalization, streetscapes, and trail and open space planning. She serves as both the national Discipline Lead for Landscape Architecture and Urban Design and the Business Development Manager for Dillon’s Public Space Design service offering.

In these leadership roles, Kate drives strategic growth and promotes design excellence across multidisciplinary teams— experience that directly informs her perspective and contributions as a new member of the OALA Council. Her ability to bridge business development, design leadership, and professional advocacy positions her to support the advancement of the profession and the Association’s goals.

Kate specializes in designing functional, pedestrian-focused public spaces for large-scale municipal park projects, and brings extensive experience in transit-integrated public realm design. Her design approach is rooted in equity, accessibility, and quality, with a focus on delivering inclusive, and innovative solutions that balance functionality with aesthetics.

She holds a professional diploma in Landscape Architecture from Toronto Metropolitan University and is a full member with seal of both the Ontario Association of Landscape Architects and the Atlantic Provinces Association of Landscape Architects. Kate also contributes to the profession through volunteer engagement with the University of Guelph and remains actively engaged in OALA events and initiatives.

Matthew Campbell
Secretary

Matt is a Senior Contractor Administrator at CF Crozier & Associates in Collingwood. He has worked on projects of all sizes, which include, large four-season resorts, transit projects, public parks, trails, private sector development and small residential designs. Matt obtained his Bachelor of Landscape Architecture from the University of Guelph in 2014. He has a strong background in plant material and construction. Having the ability to translate ideas into practical and workable designs, Matt enjoys bringing projects full circle from concept design to the final built form. He is looking forward to the opportunity to represent the OALA membership and to work with Council to advance the profession of landscape architecture in Ontario.

Steve Barnhart
Past President

Steve Barnhart is a Senior Director at Niagara Parks responsible for parks operations, horticulture programming and environmental planning. Prior to Niagara Parks Steve was responsible for managing forestry and horticulture operations and design development and implementation of open space capital projects for the City of Hamilton. Steve has worked on a wide range of projects including master plans, waterfront development, transportation, storm water management systems and visual impact assessments. Steve has been a full member of the OALA since 2000 and graduated with a Master of Landscape Architecture from the University of Guelph. Steve has previously served for 6 years as a volunteer on the OALA Continuing Education Committee. Steve is also an Adjunct Professor at the University of Guelph Environmental Design and Rural Development. In 2016 Steve received the OALA Public Practice award.

Ashley Hosker
Councillor

Ashley is a landscape architect with the City of Kitchener. Her experience spans large- and small-scale projects across diverse communities through both private consulting and municipal practice. Experience in consulting provided a strong foundation in design, project delivery, and interdisciplinary collaboration, and has informed her transition to the municipal side of the profession. This dual perspective allows her to understand both the challenges and the broad role landscape architects play in shaping strong, resilient communities through creative problem-solving.

Ashley obtained her Bachelor of Landscape Architecture from the University of Guelph in 2018 and became a Full Member of the OALA in 2022. She has been actively involved with the OALA Honours, Awards and Protocol (HAP) Committee since 2022 and is excited for the opportunity to represent the OALA membership on Council and strengthen connections across the profession.

Lynda Macdonald
Councillor

Bio coming soon

Matthew Perotto
Councillor

Matt Perotto, OALA, CSLA, ASLA, is a Principal Urban Designer and Landscape Architect at Urban Strategies Inc. His work focuses on the integration of landscape architecture and urban design through socio-cultural and ecological systems, advancing how public realm projects engage with computation, data, and emerging artificial intelligence.

Prior to joining Urban Strategies, Matt was a Senior Associate at Janet Rosenberg & Studio, where he led the development of the Studio Research Lab, including the firm’s Sustainability Action Plan and in-house computational design tools.

Alongside practice, Matt is a Sessional Lecturer II at the University of Toronto Daniels Faculty, where he teaches visual communication, computation, and integrated urbanism, and advises graduate thesis work.

Matt has served as a Councillor with the Ontario Association of Landscape Architects since 2023 and actively contributes to various committees within the OALA and the ASLA’s Digital Technologies Professional Practice Network.

Khadija Kushalgadhwala
Intern Councillor

Khadija is an Intermediate Landscape and Urban Designer with 7+ years of experience in landscape architecture, urban planning, and project management across Canada and the Middle East. She has contributed to streetscapes, urban parks, residential communities, and municipal projects, integrating sustainability, accessibility, and aesthetics. With a Master’s in Urban Planning from Newcastle University and a Bachelor’s in Architecture from NMIMS, she combines strong academic knowledge with hands-on expertise. Her work with multidisciplinary teams, municipalities, and international firms at Fathom Studio in Halifax and previous roles in Dubai and India has given her a global perspective on landscape design trends and best practices.

Emiley Switzer-Martell
Intern Councillor

Bio coming soon

Elise Shelley
Appointed Educator, Daniels Faculty of Architecture, Landscape and Design, University of Toronto

Elise Shelley is an Associate Professor at the Daniels Faculty of Architecture, Landscape, and Design at the University of Toronto and the Director of Landscape at gh3*. She a registered landscape architect with 20 years of experience in projects of all scales. Shelley’s background and training in both architecture and landscape has enabled a method of practice that emphasizes the physical, experiential and functional connections between interior and exterior space. Her teaching portfolio includes Site Engineering, Studio, Planting Design, Professional Practice and Thesis advising.

Focused on the interdisciplinary nature of urban places, Shelley’s work addresses material innovation, community. engagement and ecological resilience. Award-winning urban playspace projects include gardens and playgrounds for city daycares, public schools and non-profit organizations. In addition to having her Landscape Architecture licensure in the United States and Canada (Ontario and Alberta), Shelley is certified in Playground Safety Inspection by the U.S. National Recreation and Park Association.

Shelley has lectured throughout North America and Europe and her work on resilient landscapes and contemporary children’s playspaces has been presented at several international conferences.

Afshin Ashari
Assistant Professor, Landscape Architecture at the School of Environmental Design and Rural Development, University of Guelph

Afshin Ashari is an Assistant Professor in Landscape Architecture at the School of Environmental Design and Rural Development (SEDRD). Prior to joining SEDRD, he was engaged in a range of architectural and landscape architectural projects in both public and private sectors and most recently working with Brook McIlroy Inc. in Toronto; an interdisciplinary firm of architects, landscape architects, planners, and urban designers.

He has a Masters in Landscape Architecture from the University of Toronto and a Bachelor of Computer Engineering from the Azad University of Tehran. Afshin has always been passionate about merging the two worlds of computer science and design. He is interested in implementing novel approaches that bridge traditional and computational design processes, with the hope of avoiding analogue habits of design and landscape homogenization.

Taking advantage of his interdisciplinary background in landscape architecture and computer science, his research interests lay within the fields of computational, parametric, and digital design representation activities for landscape architecture involving advanced technological tools in contemporary design media and professional practice.

Karen Liu
Lay Councillor

Dr. Karen Liu is the Green Roof Specialist at Next Level Stormwater Management, bringing over 25 years of green roof experience across North America, Europe and Asia. As a seasoned researcher and educator formerly with the National Research Council Canada and the British Columbia Institute of Technology, she bridges technical expertise with practical application in nature-based solutions. Karen actively contributes to industry advancement as a member of the CSA A123 Technical Committee, serves on the Editorial Board of Green Roofs for Healthy Cities’ Living Architecture Monitor and on the Board of Directors for the Green Roof Infrastructure Network BC. Passionate about climate resilience, Karen collaborates closely with landscape architects on many green roof projects to build a sustainable future and is honoured to serve as the Lay Councillor for the OALA.

Amber Mays
Student Representative, University of Guelph

Amber Mays is currently pursuing her bachelor's degree of Landscape Architecture at the University of Guelph and previously served as Co-President of the University of Guelph's Landscape Architecture Student Society. Amber’s strong passion for the environment has led to employment as a tree planter and she has also worked for the city of Toronto with Parks and Recreation. She loves working in collaborative environments and enjoyed volunteering with LABASH in 2025. Amber is excited to connect the OALA with students and hopes to share her passion for the environment with others.

Jeffrey Carter
Student Representative, University of Toronto

Bio coming soon