# USA Forests' Deforestation

L. David Roper
http://www.roperld.com/personal/roperldavid.htm
7 September, 2017

Rain Forests

## Introduction

In my quest to analyze data of global systems that are affected by or affect global warming, I have been looking for data about the deforestation of USA forests to analyze.

## United States Forests' Data

The best data I have found are in the following graph:

Go to top.

I digitized all four curves and added the results to get values for the entire USA:

 year South North Pacific Rocky Mts Total (10^6 acres) 1630 356 297 242 155 1050 1669 356 298 242 155 1051 1712 356 296 242 155 1049 1733 356 295 242 155 1048 1743 356 294 242 155 1047 1754 355 293 242 155 1045 1765 353 293 242 155 1043 1776 353 288 242 155 1038 1787 352 287 242 155 1036 1797 350 282 242 155 1029 1807 348 275 242 155 1020 1817 346 267 242 155 1010 1828 342 255 242 155 994 1839 337 241 242 155 974 1849 331 226 242 155 954 1860 327 219 242 155 943 1869 313 204 241 154 912 1880 305 185 240 153 883 1890 284 159 239 152 834 1900 265 149 238 152 804 1912 244 139 237 151 772 1923 230 135 238 149 752 1934 223 153 237 148 761 1944 229 158 231 142 760 1954 229 163 231 141 764 1965 221 163 226 140 750 1974 214 164 223 141 742 1983 215 166 222 142 746 2002 218 167 222 143 751

More recent data: 2010: 751.3; 2012: 766.2

## Fit to the Data

I used the hyperbolic tangent function to fit the data. The best fit is:

The fit is , where a = 1043, b = 757.0, t0 = 1869 and w = 42.23 .

Go to top.

## Conclusion

Forest area in the United States has stopped the sharp decline that existed for about 100 years. However, recent research indicates that USA forests are slowly continuing to decline area by about 6x106 acres per year.

## References

http://news.mongabay.com/2010/0427-hance_forestloss.html:

Go to top.

## Forest Fires

From https://www.nifc.gov/fireInfo/fireInfo_stats_totalFires.html:

L. David Roper interdisciplinary studies

L. David Roper, http://www.roperld.com/personal/roperldavid.htm