Evaluation of a Landscape Analysis Approach for Migratory Birds and Species at Risk Habitat Conservation Planning in the Mixedwood Plains Ecozone: Case Study in Lake Saint-Pierre

Environment Canada’s Canadian Wildlife Service (CWS), Quebec Region, has conducted a pilot project to develop and test a method to identify priority sites for migratory bird conservation within Bird Conservation Region (BCR) 13, located in the Mixedwood Plains ecozone. The approach is based on the landscape ecology theory, making it possible to associate habitat needs of priority bird species with a finer description of habitat composition and spatial distribution. This landscape-based approach is more integrative and allows for work on a broader scale instead of the more conservative approach based on known priority sites (hot spots) traditionally used in conservation planning. A logic model illustrating the steps for preparing a conservation plan was developed and tested. The Lake Saint-Pierre region (included within BCR 13) was selected as the study area. The goal of the project was to determine the current and potential structure of the landscape in order to maintain and restore functional and viable habitats for the priority species for this project. A total of 48 species identified in the BCR 13 conservation plan as species of conservation concern were selected, including species at risk for which critical habitat was proposed or designated. The issue regarding those priority species is for the most part associated with breeding habitat availability. A land cover map of the study region has been produced and validated. A total of 7 general (anthropogenic, shrubland, annual crops, perennial crops, water, forest, wetland) and 21 detailed land cover classes were delineated. Data on the protected areas and species at risk present in the study area were also compiled. The analysis performed with ArcGIS and FRAGSTATS software was divided into two major components: 1, descriptive analysis; and 2, landscape functionality. The analysis was performed at the study area level, at the regional county municipality (RCM) scale and at the watershed scale. The last two spatial units were selected because they foster effective implementation of the conservation recommendations whereby priority sites can be considered in regional land-use planning activities. The study area is largely dominated by agriculture: annual and perennial crops cover 31% and 20% of the study area respectively, followed by forest (24%), open water (10%), wetlands (10%), anthropogenic areas (4%) and shrubland (which accounts for only 1% of the area). A detailed analysis also identified portions of the study area most suitable for forest birds, where forest fragmentation is reduced and where forest interior habitats still prevail. Landscape functionality was analyzed by comparing the composition of the landscape with known habitat thresholds, by identifying movement corridors for forest birds, and by assessing the availability of certain classes of priority habitat. The thresholds used to compare the landscape of the study area, RCM and watersheds were taken from the document How Much Habitat is Enough? and focused on forest habitat, wetlands and riparian buffer strips. Forest habitats are under-represented in the study area, though forest interior habitats could probably support forest bird populations. Wetlands are abundant around Lake Saint-Pierre, but their presence is limited in the rest of the area. Furthermore, the integrity of these habitats is at risk because the adjacent habitats are strongly influenced by human activity. The same is true for riparian buffer strips. The identification of movement corridors for forest birds focused on connecting forest patches > 1000 ha. Using Corridor Designer software, 14 movement corridors were selected based on pre-established criteria (width > 300 m; distance between woodlots 100 ha, perennial crops > 40 ha, shrubland > 5 ha, marsh > 5 ha, shrub swamp > 5 ha, peatland > 20 ha). All patches of forest swamp and wet meadow were considered priority sites because no minimum area threshold is known for those habitat classes. The best patches in each habitat class were then prioritized according to a series of criteria related to their significance for the establishment and maintenance of nesting bird populations (e.g. patch shape, % of interior habitat) or their ecological role in the landscape (e.g. creation of a buffer zone around protected areas, presence of species at risk). Finally, other habitat components specific to certain species (fine-filter approach) such as sand pits and rocky outcrops in forest environments were also identified. A diagnosis of the ability of the landscape to provide functional habitat for priority bird species was performed. The deficiencies noted in the study area included the limited surface area occupied by shrubland (1%), the lack of forest cover (< 30%), the inadequate distribution of wetlands (few are located outside the immediate vicinity of Lake Saint-Pierre), severe disturbance of riparian buffer strips, and forest corridors that do not meet the established criteria. A conservation plan for migratory bird and species at risk habitat was developed taking into account the description and analysis of landscape functionality, as well as regional development issues. The conservation plan proposes detailed conservation actions at the RCM and watershed scales: prioritization of spatially explicit habitat patches (habitat of avian species at risk, coarse- and fine-filter patches, forest corridors), protection of non-spatially explicit habitat components (e.g. large-diameter snags, Purple Martin nest boxes), and landscape attributes to be considered for the maintenance of ecological processes (e.g. vegetated riparian buffer strips). The conservation plan must be validated at the site level because the data on certain habitats may be outdated. Possible actions and proposals for the implementation of the conservation plan are also presented. Lastly, a general summary of the project points out the benefits and some shortcomings of the landscape-based approach that was used and highlights some problems encountered. A suite of recommendations are proposed to help with the application of the approach and to support a joint involvement of partners and stakeholders in land use planning.

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