Tree Diversity in Prairie Urban Centers

Based on tables presented above there are several conclusions:

• Tree diversity (species richness) in Prairie urban municipalities is extremely high comparing to natural forest surrounding the urban areas.

• Genus diversity (genus richness) is also very high including tree species that belong to Plant Hardiness Zone 5, 6 and 7.

• Despite high species richness, normally a few genus (elm, ash, poplar, spruce, and pine) dominate the urban tree population.

• Ulmus, Populus and Fraxinus genus are most dominant hardwoods (40-55 %) by total number of trees.

• Picea and Pinus genus are most dominant coniferous (15-30 %) by total number of trees.

• There is significant number of tree varieties and clones planted in urban areas.

• There are some variations regarding tree species diversity among various urban municipalities. Variations are based on local climate, site, and soil but also on urban forest managers’ decision on species selection as well as available local tree nursery stock supply.

• Flowering tree species (Malus, Prunus and Tilia) consist of 5-20 % of the urban trees.

• Total number of trees planted and inventoried is significant considering that just 100 years ago most of urban municipalities were Prairie grassland.

Summary

As this is first time that Prairie urban municipality tree diversity is summarized and analyzed (partially), we offer the following suggestions to prairie urban municipalities:

• Standardize the tree inventory methodology and software across the prairie provinces.

• “Clean up” tree data to remove overlapping and incomplete data information.

• Use latest technologies (e.g. LiDAR, AI, air photo, SEGMA software, Google street view, etc.) to conduct tree inventory, that is cheaper and faster than traditional individual tree inventory.

• Perform tree inventory audits to analyze your tree data not just on tree diversity but also on tree age, overall health and vigour, survival rates, site conditions, pest infestation, care, and maintenance history.

• Analyze species diversity, but also diversity within a species, cultivars, clones, as well as age and size diversity.

• Most of tree species are not native but introduced tree species have already adapted, survived, grown, and thrived in last 120 years in Prairie urban centers.

• Climate change will impact trees in urban centers in many ways but many tree species already adapted to impact of climate change.

• Analyze the performance of each tree species and determine which species, cultivars and clones are best suited to your urban environment.

• Collaborative work is required among urban municipalities, landscape architects, developers, tree nursery growers, research institutions, colleges, and universities to develop climate change adaptive tree species selection system.

• Pests threat is real to trees in urban centers and developing coordinated plan how to monitor, survey and control spread of pests.

As Prairie urban centers are experiencing recent pest outbreaks as well as the environmental changes resulting from climate change, understanding current tree species diversity, and planning for future tree diversity is crucial. Urban Prairie environment is tough to many trees but as we already have over 100 years experience with tree diversity in urban centers and through proper past assessment, knowledge and experience we can achieve a resistant, diverse, and resilient future urban forest. ATTS Group Inc offers reliable, practical, and innovative tree and forestry consulting and advisory services to urban municipalities. We offer tree audits, inventory, management plans and arborist consulting services.