PRINCE GEORGE NATURAL AREAS AND THE EFFECTS OF CLIMATE CHANGE: CASE STUDY
Natural Areas in Prince George The City of Prince George is dominated by natural, undeveloped areas within city limits and in adjacent areas. The extensive forests and natural areas found within its municipal boundaries provide excellent recreational opportunities and add to the overall health and aesthetics of the community. Residents of Prince George consistently identify the natural areas as a key value of the City and they have a strong desire to look after the environment. Natural areas provide important habitat to hundreds of species of animals and plants, as well as many bacteria, fungi and other smaller organisms. The age and composition of natural areas determine what species are present and how that ecosystem functions on the land base. For example, one natural area may provide breeding habitat for birds in the spring, food for deer in the winter, it may stabilize steep slopes through the root systems, absorb greenhouse gases, and reduce the risk of flooding and erosion. In order to protect and promote natural areas for the future, the City of Prince George has embarked on numerous projects to map natural areas, identify the most sensitive areas, assess how climate change may affect these areas over time, and develop strategies to manage and monitor natural areas within city limits. 1
Climate Change Impacts on Prince George The earth is currently experiencing a global warming trend and Prince George natural areas will change over time. Within the Prince George region, it is expected that there will be increased levels of precipitation, increased air temperatures, and reduced amounts of water available in the soil for plants. The recent Mountain Pine Beetle epidemic and the increase in wildfires within the Prince George region are both connected to rising temperatures during the winters seasons. As a result of the pine beetle epidemic, the majority of pine forests in and around Prince George have been destroyed, leaving a drastically changed landscape and a general concern about the community s safety and economic future. Information about the potential effects of climate change on natural areas in Prince George is a valuable resource for successful long term planning. Natural Areas Project Overview During the Integrated Community Sustainability Plan (mypg) process and Official Community Plan review, the city of Prince George recognized that both processes would benefit from additional studies of the city s natural areas. In an effort to better understand and manage the natural areas within city limits, the City of Prince George embarked on a series of studies between 2010 and 2012: Phase I: Mapping of Natural Areas; Phase II: Effects of Climate Change on Natural Areas; Phase III: Management and Monitoring Plans ; and Phase IV: User-Friendly Information Release. This series of projects may be useful to other local governments looking to incorporate the potential impacts of climate change into their land use decisions and management of natural areas. The project steps can be completed concurrently or broken up into logical phases in order to secure support for each of the individual studies. 2
Study 1: Mapping Natural Areas A foundation inventory of natural areas provides many benefits to a municipality and can be used in various studies and planning exercises for many years to come. Ecosystem maps provide a foundation inventory of the natural areas and are used in different ecological assessments such as climate change modeling, biodiversity monitoring, and wildlife habitat suitability mapping. This information can help multiple user groups discover what the biological resources are in the city, where they occur, and how they are connected. With natural areas mapping, city managers and planners can use a landscape-level ecological framework (i.e. mapped natural areas with similar vegetation structure and composition) when making decisions regarding future land use for these areas. In 2010, the city of Prince George hired a specialist to prepare a detailed Terrestrial Ecosystem Map (TEM) and associated Sensitive Ecosystem Inventory (SEI) for all of the undeveloped and natural areas within the city s limits. TEM is a very technical, but standardized method in British Columbia that divides the landscape into map units based on features such as climate, soil, and vegetation. The maps produced using this method are a comprehensive display of a significant amount of ecological data. Simplification of these maps for uses by non-experts was necessary and is described later. SEI uses the information from the ecosystem mapping and highlights those areas that are sensitive. An ecosystem is often considered sensitive if it: is listed by provincial experts as endangered, threatened, or of special concern; contains known species at risk; has important wildlife habitat or; has other values such as improving drinking water quality, providing natural fire-breaks The full report for the TEM and SEI project is available on the City of Prince George website at: http://princegeorge.ca/citybusiness/longrangeplanning/temandsei/default. 3
Simplified Ecosystem Mapping The TEM and SEI maps and data is very complex and only ecological experts can typically use and understand the data. To make the information usable by a wide variety of people and groups, the 116 ecosystems identified in the TEM and SEI were combined into 14 simplified map units. The simplification process ensured that ecosystems were combined based on their similarities in function on the landbase, their sensitivity to climate change, as well as their unique management requirements. These are listed below: Provincially Sensitive Ecosystems 1. Rare Dry Forest; 2. Rare Mature Forest; 3. Rare Riparian Areas and Wetlands; 4. Rare Grassland; Locally Sensitive Ecosystems 5. Sensitive Dry Forests; 6. Sensitive Dry Non-Forested Ecosystem; 7. Sensitive Riparian Areas and Wetlands; 8. Sensitive Old Growth Forests; Non-Sensitive Ecosystems 9. Common Douglas-fir Forest; 10. Common Coniferous Forest; 11. Common Mixed Forest; 12. Common Deciduous Forest; 13. Common Non-forested Area; and 14. Urban / Developed Areas. 4
Final Simplified Ecosystem Map This map can also be viewed online through the PGMAP tool available at: http://princegeorge.ca/cityservices/online/pgmap/pages/default.aspx 5
Area (ha) Study 2: Effects of Climate Change on Natural Areas Drought is expected to be one of the main causes of climate change related effects on forest ecosystems because available soil moisture is often a limiting factor to vegetation establishment and growth. A study completed in 2009 by the Pacific Climate Impacts Consortium identifies the following possible effects of a warming climate in Prince George: precipitation is expected to increase by 3-10% by 2050; temperature is expected to increase by 1.6 C to 2.5 C by 2050 and; with warmer temperatures, the speed of water evaporating from the soil increases as does the speed of water uptake from plants. In response to increasing concerns about the potential impacts of a warming climate, Prince George hired modeling experts to study the expected changes in available water to natural areas and sensitive ecosystems. Climate Change Impacts on Soil Moisture The climate change study started by reviewing potential soil moisture changes because drought is predicted to be one of the biggest effects resulting from warmer temperatures. With drought conditions, there is less water available to trees and other plants which can have a huge impact on the distribution of tree and plant species in the Prince George area. The analysis focused on the forested areas because they represent over 80% of the natural areas in Prince George and drought tolerance models already exist for the tree species found in the area. The models utilized the soil moisture information collected during the TEM portion of the project. This TEM information was converted to actual soil moisture regime (ASMR) and provides an excellent measure of the moisture in the soil now and in the future. The ASMR data formed the basis for the climate change effects modeling. Extremely Dry Very Dry 2 Very Dry 1 Moderately Dry Slightly Dry Fresh Moist Very Moist 25,000 20,000 15,000 10,000 5,000-2011 2020 2050 2080 Year Future climate scenarios were modeled using the TACA model (a well-known modeling tool) in order to predict the ASMR changes over time. As expected, the soil moisture in Prince George s natural areas currently range from wet to excessively dry. The drier the soil moisture is, the higher the risk is for ecological degradation from the effects of 6
climatic change. The results showed the most rapid change in soil moisture is expected to happen from 2011 to 2020 where most of the natural areas experience a shift from being moderately at risk to climatic effects to being at higher risk to climatic effects. 2011 2020 2050 2080 Changes in Soil Moisture due to Climate Change from 2011 to 2080. Climate Change Impacts on Tree Species The risk to individual trees was also examined as trees are the dominant vegetation in most natural areas and play a significant role in an ecosystem s structure, composition and function. The level of risk of climate change related mortality or increased stress to tree health is based on the site characteristics and the species sensitivity to drought. Site specific information available from this phase provides land managers with resources to consider the possible effects of increased temperatures on tree species within the city of Prince George. 7
Area (ha) Climate Change Impacts on Sensitive Ecosystems Climate change impacts on sensitive ecosystems are important to consider because many of these sensitive areas support trees that are already experiencing dry growing conditions. Even small reductions in soil moisture can cause stress and mortality in the species within those areas. The sensitive ecosystems studied included ecosystems that were considered rare or endangered in BC. Of the identified provincially sensitive areas from the natural area mapping study, approximately 77% were found to have high or very high risk of impacts from climate change. 2,000 1,800 1,600 1,400 1,200 1,000 800 600 400 200 - Very High High Low Blue Red SEI Class The full report for the Climate Change Effect on Natural Areas project is available on the City of Prince George website at: http://princegeorge.ca/citybusiness/longrangeplanning/temandsei/default 8
Study 3: Management and Monitoring Plans for Climate Change Effects on Natural Areas For the next phase of this project, it was time to focus on putting the information learned from the earlier phases into action. This involved developing clear management strategies, best management practices, and a monitoring plan for the predicted effects of climate change on Prince George s natural areas. Maintaining large areas of undisturbed forests and wetlands is considered key for maintaining sensitive ecosystems, wildlife species and their habitat. These high conservation value areas require important management consideration. Specific management strategies vary according to the realities associated with different zones such as urban, future urban and rural areas, as well as safety considerations, wildfire control, etc. Management plans were established by completing the following: Identify high conservation value areas; Identify unique management zones; Write best management practices for each natural area; and Develop monitoring strategies. Identifying High Conservation Value Areas Not all natural areas have the same value from a conservation and management perspective. For example, a wetland on the edge of a major highway has less wildlife value than a wetland in the middle of an undisturbed forested area. It was therefore important to classify the conservation value of each natural area within city limits to allow for different management practices to be used for high value versus standard value areas. To assign conservation value, characteristics of the natural areas were evaluated including: Intactness of forest Ecosystem size Ecosystem age since last disturbance Leading tree species Existing OCP zone 9
Identifying Unique Management Zones Management of natural areas must account for the existing uses, future uses identified in the official community plan, and areas previously identified by the city as being extraordinary in some manner. The following zones were considered to have unique management requirements: Wildfire Interface Zones Agricultural Land Reserve Parks Riparian Protection Development Permit Areas Groundwater Protection Development Permit Areas Landslide Hazard Areas Flood Hazard Areas Rural Resources Areas Rural Areas Urban Areas Proposed Urban Areas Best Management Practices for Natural Areas The best management practices (BMP s) were written for each combination of ecosystem / conservation value / management zone. Every natural area polygon has BMP s available to provide guidance on their value and management. The BMP s were designed to be easily implementable and understandable for a wide range of users including managers, planners and the general public. Example BMP statements include: This high conservation value site should remain as undisturbed as possible, with a 100m no disturbance buffer, Avoid fuel management and vegetation conversion within this polygon if possible Actively remove the invasive species found within 1km of this site Inform and educate the landowner about the presence of a rare ecosystem on property These areas are especially susceptible to vegetation conversion due to climate change - where forest health issues are prevalent, under-plant these slopes with Douglas-fir Stabilize slumping areas with vegetation native to this rare ecosystem such as soopolallie and common juniper Maintain connectivity corridor between wetlands and riparian areas If new permanent structures are planned within GPDP, do not develop within 30m of rare riparian areas and wetlands 10
Develop Monitoring Strategy Monitoring the effects of climate change and the impacts of best management practices on the structure, composition and function of natural areas over time is clearly important to meet the City s objectives concerning the environment. Prior to developing a monitoring framework, it was important to identify what type of monitoring is being completed and the objectives of the monitoring plan. There are several forms of monitoring that are typically undertaken for ecological diversity and health of ecosystems. The appropriate type and level of monitoring was selected based on several factors including the project area, management objectives, climate change risk assessment, and general management practices being used in the area. Effectiveness monitoring of legislated requirements and best management practices for environment values was considered an appropriate form of monitoring natural areas in Prince George over time. The general landscape level values to monitor are captured in the City OCP and in the existing Environment Strategy for Open Space. Several environmental values are identified in the OCP; however, the following are the most relevant landscape values that require monitoring in the face of climate change and municipal development: Environmentally sensitive areas; Key wildlife habitat; and Riparian areas. The following analyses were selected to be completed as a component of the monitoring plan over time: Indicator 1: The number of hectares of high conservation value Environmentally Sensitive Areas on the land base; Indicator 2: The number of hectares of Environmentally Sensitive Areas Protected in Parks; Indicator 3: The number of hectares of key wildlife habitat; and Indicator 4: The percentage of new development with appropriate setbacks from streams and wetlands. Each of these indicators has a description of the importance, baseline data generated for 2012 conditions, targets for future results and instructions on how to monitor the indicator. The full report for the Climate Change Effect on Natural Areas project is available on the City of Prince George website at: http://princegeorge.ca/citybusiness/longrangeplanning/temandsei/default 11
Study 4: User-Friendly Information Release Ecosystems and climate change are complicated and connected subjects, however the evidence of climate change effects are becoming increasingly obvious. By providing the valuable information about Prince George s natural areas and the potential impacts of climate change in an easy to understand format, it is hoped that there will be better discussions and more informed decisions about land use and planning developments in the city. Sharing information about these studies with other local governments is hoped to encourage environmental considerations and stewardship in their planning processes as well. All information related to these studies has been made available on the Prince George website. The interactive mapping tool on the Prince George website called PGMAP (http://princegeorge.ca/cityservices/online/pgmap/pages/default.aspx) houses all of the simplified ecosystem maps and related documents. Users can select the property they are interested in and determine the type of natural area, its sensitivity to climate warming, and the best management practices for that property. In addition, this case study is available on the city website, as well as a copy of a powerpoint presentation describing these projects in slide format. 12
Where to From Here? Now that the information has been collected and a management plan has been developed, it is time to apply these strategies and best management practices in the natural areas planning processes. The recommended monitoring plan will help measure how effective these strategies are at meeting the targets. Just as the climate and the nature of ecosystems changes over time, so do the questions that surround these issues. In order to consider these potential changes and review any existing management strategies in the development of future management plans, some recommendations for future action include: studying the effects of climatic change on wildfire activity and on invasive species; revisiting and updating the forest inventory; setting up a network of permanent sample plots to monitor the effects of climate change over time adjusting the monitoring plan to include results of field monitoring forest health maps; invasive species maps; carbon budget modeling; wildlife corridor mapping. By pursuing these strategies for managing the natural areas and potential climatic effects in Prince George, the city is reinforcing the importance and value that these natural areas have for the community. As suggested in Prince George s Sustainability Plan, the city continues to be guided by a sustainability consciousness, and this series of projects has demonstrated that the City of Prince George is a strong champion of sustainable development. 13