Historical summaries

In early Forest Resources of Ontario reports, forest cover was surveyed according to broad cover types and seral stages, essentially mature, immature and young growth forest, as the inventory was purely for commercial logging purposes. It wasn’t until 1986 that the concept of age class was introduced to the report. Working groups (dominant species) and 20 year age classes were published in 1986 and this report series has carried that tradition through for comparative purposes. Forest units based on ecological characteristics were not introduced until the mid-1990s.

Volume measurements (growing stock) were published earlier than age class summaries. Therefore the growing stock historical summaries report back to 1963. It should also be noted that changes in the methods of data collection and summarization should be considered when examining historical trends.

Area by age class and year - all working groups

vertical bar graph of all working groups area by age class including light brown for 1986, brown for 1996, green for 2006 and charcoal for 2016.

Total area by tree species group and report year–AOU (area in hectares) footnote *

Working group 1986 1996 2001 2006 2011 2016
White Pine 574,446 693,682 778,947 790,899 789,788 790,324
Red Pine 159,378 132,590 149,180 164,582 174,875 175,375
Jack Pine 4,425,377 4,608,320 4,598,671 4,678,563 4,752,693 4,733,043
Black Spruce 13,477,431 13,095,277 12,952,361 12,976,168 12,774,963 12,816,829
White Spruce 285,109 295,956 303,819 326,835 330,990 337,443
Balsam Fir 1,873,475 1,775,390 1,371,623 926,922 935,450 937,419
White Cedar 693,596 652,253 725,226 786,220 765,007 765,495
Hemlock 159,769 150,181 152,371 150,579 157,654 159,640
Other Conifers 212,934 171,277 196,392 210,849 258,564 261,934
Poplar 5,041,874 5,704,712 5,874,789 5,937,184 5,907,699 5,911,289
White Birch 2,845,871 2,950,846 2,998,912 3,114,749 3,190,415 3,218,226
Hard Maple 2,205,012 1,856,763 1,855,585 1,875,522 1,838,283 1,823,569
Oak 285,743 226,311 308,283 284,090 280,896 283,797
Yellow Birch 163,897 138,992 155,178 153,907 165,695 165,937
Other Hardwoods 475,969 423,664 441,425 485,693 473,017 482,443
Total: 32,879,880 32,876,215 32,862,762 32,862,762 32,795,989 32,862,762

Generating summaries for the Forest Resources series prior to the 1990s was a significant undertaking, as most work was done on paper maps and ledgers. The focus of the reports was generally on more important commercial species such as spruce and pine. Photo interpreters would often ignore small amounts of Poplar or White Birch in large coniferous stands.

During the 1990s, stand sizes started to shrink and become more complex, as interpreters were highlighting subtle differences in height, species composition or other physical features. Small amounts of other species were introduced into the provincial inventory, giving the impression to those viewing summaries that there was an increase in these species. In reality it was simply an increase in detail. An examination of the successive inventories where no harvest or natural disturbance has occurred has shown a 50-80% increase in the number of stands marked as individual polygons, and a significant increase in Poplar, Balsam Fir and other incidental species.

Footnotes

  • footnote[*] Back to paragraph Note: there have been adjustments made to historical numbers to match the current AOU boundary; numbers do not reflect the Whitefeather Forest.