Canada’s human footprint reveals large intact areas juxtaposed against areas under immense anthropogenic pressure

Efforts are underway in Canada to set aside terrestrial lands for conservation, thereby protecting them from anthropogenic pressures. Here we produce the first Canadian human footprint map to identify intact and modified lands and ecosystems. Our results showed strong spatial variation in pressures across the country, with just 18% of Canada experiencing measurable human pressure. However, some ecosystems are experiencing very high pressure, such as the Great Lakes Plains and Prairies national ecological areas which have over 75% and 56% of their areas, respectively, with a high human footprint. In contrast, the Arctic and Northern Mountains have less than 0.02% and 0.2% under high human footprint. A validation of the final map resulted in a Cohen Kappa statistic of 0.911, signifying an ‘almost perfect’ agreement between the human footprint and the validation data set. By increasing the number and accuracy of mapped pressures, our map demonstrates much more widespread pressures in Canada than were indicated by previous global mapping efforts, demonstrating the value in specific national data applications. Ecological areas with immense anthropogenic pressure, highlight challenges that may arise when planning for ecologically representative protected areas.


Introduction 30
Global pressures to biodiversity are increasing as human use continues to alter terrestrial 31 ecosystems (Steffen et al., 2015;Venter et al., 2016a), leading to accelerating biodiversity 32 declines (Maxwell et al., 2016;Newbold et al., 2015). Anthropogenic pressures to biodiversity are 33 actions taken by humans that have the potential to harm natural systems (Venter et al., 2016a).  Table 2). 193

Navigable waterways 194
Navigable waterways like roads and rails act as means of access to wilderness areas. Canada's 195 waterways have a long history of human use as they have enabled travel from sea to sea (Brine, 196 1995). Once the people's 'highway', settlements were formed along the waterways to allow 197 movement and access. Used by First Nations in pre-colonial times, the knowledge was shared 198 when the first European explorers arrived. These waterways were later instrumental in the fur trade 199 (Brine, 1995;O'Donnell, 1989). 200 We used the dataset generated for navigable coasts for 2009 from the global human footprint with 201 a 1 km 2 spatial resolution (Venter et al., 2016b). The layer included the Great Lakes, as they can 202 act like inland seas and was generated using distance to settlements, stream depth and hydrological 203 data (Venter et al., 2016b). We found the centreline of the waterway then weighted them to follow 204 the other access-based layers (Table 3). 205

Dams and reservoirs 206
Dams directly change hydrology of the areas and they modify the 207 environment, often producing human-made flooded reservoirs (Woolmer et al., 2008). The vector 208 dataset was obtained from 'Large Dams and Reservoirs of Canada' (Global Forest Watch Canada, 209 al., 2016aCanada, 209 al., , 2016bWoolmer et al., 2008). We scored dams and associated reservoirs in the same 211 manner as navigable waterways given that they can provide additional access to areas by watercraft 212 (Table 3). 213

Mining 214
Mining often alters topography, watercourses and removes topsoil as a form of land conversion. 215 Mining can be a point source for air and water pollution (Woolmer et al., 2008 The forest-harvest data were obtained from an annual forest disturbance characterization project 241 for Canada that has a 30-metre spatial resolution ( (Fig. 1). With the 12 pressures included, we found that 82% of Canada's land 280 areas had a human footprint score of less than 1, and therefore were considered intact (Allan et al., 281 2017). In this context, intact is defined as landscapes that are mostly free of the 12 human 282 disturbances we mapped. To conceptualize this definition of intact, cells that had a population 283 density of one or more people per square kilometre obtained a pressure score of one or above and 284 were therefore not considered intact. However, pressures such as seismic lines, pollution or 285 invasive species were not mapped and may be present in areas that we identified as intact. The low 286 human footprint state was defined as areas where the human footprint score was between one and 287 four. The upper limit was determined based on the assignment of a score of four for pasture land, 288 which would often have fences fragmenting the connectedness (Venter et al., 2016a). 289 Approximately 5% of Canada was classified in the low human footprint state. The moderate human 290 footprint areas had scores between four and 10 and covered 7% of the country. The areas of high 291 human footprint, with a value of 10 or higher, covered 6% of Canada and highlighted areas with 292 multiple overlapping pressures to biodiversity (Fig. 1). 293 We used national ecological areas defined by COSEWIC as a means of comparing the different 294 ecological regions of Canada (COSEWIC, 2018). The human footprint differs markedly across 295 those areas, with 84% of the Boreal ecological area, which covers the largest extent of Canada, 296 still being intact. The Great Lakes Plains, the smallest ecological area, has 76% in the high human 297 footprint category, being the largest percentage in the high category compared to all other 298 ecological areas. The Prairies follow the Great Lakes Plains as the second largest values in the 299 high human footprint category with 57%. The Great Lakes Plains has the smallest percentage in 300 the intact category with a value of 0.6% followed by the Prairies with 8%. Conversely, the Arctic, 301 which is the second largest ecological area, is over 99% intact. 302 The pressure layer that contributes the most towards the mean human footprint of Canada is roads 303 with a mean human footprint score of 0.72 (Fig. 2)  showing a lower human footprint score than the global one ( Fig. 3 d, e, f). In natural resource 316 intensive areas, higher scores for the Canadian human footprint are present compared to the global 317 product that missed these features across Canada. For example, in the boreal ecological area, 318 forestry harvest and infrastructure from oil and gas could be included with the Canadian human 319 footprint (Fig. 3 g, h, i). 320 When mapping nationally explicit data the greatest improvements to the global datasets were found 321 with the National Roads Network and the Annual Crop Inventory. The global human footprint 322 scores roads within Canada as 50% less of a pressure than the Canadian human footprint. The 323 Annual Crop Inventory that was used for mapping crop land for Canada captured over 285,000 324 km 2 more than the global product (Fig. 2). plots (96.8%) were within 20% agreement. While the results from the validation represent almost 334 perfect agreement, it appears from the higher false-negative rate that the human footprint map may 335 be underrepresenting the pressure scores across some proportion of the country. The maps should 336 therefore be considered as conservative estimates of anthropogenic pressures on the environment 337 (Fig. 4). When applying a more rigorous threshold for agreement, within 15% of one another, we 338 found that the Cohen Kappa statistic was of substantial strength with a score of 0.772. When 339 applying a less rigorous threshold of 25%, the Cohen Kappa statistic increased to 0.952 (almost 340 perfect strength) ( Supplementary Information, S3). , 358 yet they experience increasing pressures from human land use. There is therefore a need to protect 359 intact areas to help conserve biodiversity and ecosystem services. Furthermore, the importance of 360 large-scale and intact ecosystems is increasing as these areas become rarer (Watson et al., 2016). 361 When applying the 12 anthropogenic pressures, to the eight national ecological areas in Canada,362 we find that five of those areas have a terrestrial land mass that is over 50% in an intact state. In 363 particular, the Arctic has over 99%, the Northern Mountains has over 95% and the Boreal follows Producing the human footprint for Canada allows us to include datasets that are nationally relevant 408 and offer more information and detail than many of the global footprint maps. The largest increase 409 in mean human footprint score comes from crop land which has a mean human footprint score 410 over six times more extensive than that in the global product. The improved accuracy for mapping 411 crop land could be part of the reason we see higher footprint values in the Prairies when compared 412 to the global product, as the Prairies are a large agricultural centre for the country. Furthermore, 413 the Canadian dataset for roads allowed for the inclusion of minor roads which the global dataset 414 could not include (Venter et al., 2016b). The Canadian data also led to a near doubling of the mean 415 human footprint score for roads when compared to Canada's score with the global data. However, 416 there is still room for improvement in mapping linear infrastructure in Canada. When we compare 417 the national roads with some provincial road data, we find that the national data do not capture all 418 the resource roads and some of the smaller roads that are mapped at a provincial or territorial scale. 419 The global human footprint and the Canadian human footprint show the same overall patterns of 420 pressures. However, we find more disagreements in areas where there are more cumulative 421 pressures. By developing a finer resolution national product with Canadian data, we can measure 422 the improvements from global human footprints and confirm the soundness of our human footprint 423 with the almost perfect validation score. This demonstrates the importance of national studies for 424 conservation of biodiversity and ecosystem services (Woolmer et al., 2008). 425

Future directions 426
This is the first national product for the Canadian human footprint, with room for future 427 refinements. Firstly, linear features besides roads, such as seismic lines or outdoor recreation such 428 as trails, should be included if possible, in future revisions. These features appeared in 429 approximately 1% of the validation plots but were not mapped as there were no national datasets 430 for oil and gas exploration and recreation. Also, recreation more broadly can have significant 431 impacts (Mullins and Wright, 2016), and should be included as data become available. These data 432 should be a priority for future improvements to our work. Other pressures such as extreme weather 433 and introduced species are important, but inherently difficult to map (Venter et al., 2006; Woo-Secondly, the built environments dataset did not cover the full extent of the country (only to 59 436 degrees north), therefore the theoretical max north of 59 degrees latitude is 10 lower for the human 437 footprint, leading to a potential underestimation of anthropogenic pressure. This is unlikely to be 438 a major omission, as these pressures are sparse or absent above this latitude. Despite lower 439 population density in the north, natural resource exploration has increased, bringing with it more 440 temporary workers and work camps (Ensign et al., 2014). Thirdly, the datasets we used to map  scoring. The distances represent the scores associated with each of the buffers. 707 Table 2: Rail Pressure Scoring, separated by operational and discontinued. The distances 708 represent the scores associated with each of the buffers. 709      0-600ⅿ 600-1500ⅿ 1500-2400ⅿ 2400-5100ⅿ 5100-10000ⅿ

Mine Type
Open pit (large) 8 8 4 2 1 Open pit (small)  Information, S1. (a) the visual interpretation score assigned and location for plots, and (b) the disagreement between the Canadian human footprint score and the visual interpreted score for validation normalized on a 0-1 scale.